TTY/Serial driver updates for 6.15-rc1

Here is the big set of serial and tty driver updates for 6.15-rc1.
 Include in here are the following:
   - more great tty layer cleanups from Jiri.  Someday this will be done,
     but that's not going to be any year soon...
   - kdb debug driver reverts to fix a reported issue
   - lots of .dts binding updates for different devices with serial
     devices
   - lots of tiny updates and tweaks and a few bugfixes for different
     serial drivers.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of serial and tty driver updates for 6.15-rc1.
  Include in here are the following:

   - more great tty layer cleanups from Jiri. Someday this will be done,
     but that's not going to be any year soon...

   - kdb debug driver reverts to fix a reported issue

   - lots of .dts binding updates for different devices with serial
     devices

   - lots of tiny updates and tweaks and a few bugfixes for different
     serial drivers.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (79 commits)
  tty: serial: fsl_lpuart: Fix unused variable 'sport' build warning
  serial: stm32: do not deassert RS485 RTS GPIO prematurely
  serial: 8250: add driver for NI UARTs
  dt-bindings: serial: snps-dw-apb-uart: document RZ/N1 binding without DMA
  serial: icom: fix code format problems
  serial: sh-sci: Save and restore more registers
  tty: serial: pl011: remove incorrect of_match_ptr annotation
  dt-bindings: serial: snps-dw-apb-uart: Add support for rk3562
  tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register
  tty: caif: removed unused function debugfs_tx()
  serial: 8250_dma: terminate correct DMA in tx_dma_flush()
  tty: serial: fsl_lpuart: rename register variables more specifically
  tty: serial: fsl_lpuart: use port struct directly to simply code
  tty: serial: fsl_lpuart: Use u32 and u8 for register variables
  tty: serial: fsl_lpuart: disable transmitter before changing RS485 related registers
  tty: serial: 8250: Add Brainboxes XC devices
  dt-bindings: serial: fsl-lpuart: support i.MX94
  tty: serial: 8250: Add some more device IDs
  dt-bindings: serial: samsung: add exynos7870-uart compatible
  serial: 8250_dw: Comment possible corner cases in serial_out() implementation
  ...

Documentation/devicetree/bindings/serial/8250.yaml

@@ -77,7 +77,6 @@ properties:
               - altr,16550-FIFO64
               - altr,16550-FIFO128
               - fsl,16550-FIFO64
-              - fsl,ns16550
               - andestech,uart16550
               - nxp,lpc1850-uart
               - opencores,uart16550-rtlsvn105
@@ -86,6 +85,7 @@ properties:
       - items:
           - enum:
               - ns16750
+              - fsl,ns16550
               - cavium,octeon-3860-uart
               - xlnx,xps-uart16550-2.00.b
               - ralink,rt2880-uart

Documentation/devicetree/bindings/serial/fsl-lpuart.yaml

@@ -30,6 +30,7 @@ properties:
       - items:
           - enum:
               - fsl,imx93-lpuart
+              - fsl,imx94-lpuart
               - fsl,imx95-lpuart
           - const: fsl,imx8ulp-lpuart
           - const: fsl,imx7ulp-lpuart

Documentation/devicetree/bindings/serial/nvidia,tegra264-utc.yaml

@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/nvidia,tegra264-utc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra UTC (UART Trace Controller) client
+
+maintainers:
+  - Kartik Rajput <kkartik@nvidia.com>
+  - Thierry Reding <thierry.reding@gmail.com>
+  - Jonathan Hunter <jonathanh@nvidia.com>
+
+description:
+  Represents a client interface of the Tegra UTC (UART Trace Controller). The
+  Tegra UTC allows multiple clients within the Tegra SoC to share a physical
+  UART interface. It supports up to 16 clients. Each client operates as an
+  independent UART endpoint with a dedicated interrupt and 128-character TX/RX
+  FIFOs.
+
+  The Tegra UTC clients use 8-N-1 configuration and operates on a baudrate
+  configured by the bootloader at the controller level.
+
+allOf:
+  - $ref: serial.yaml#
+
+properties:
+  compatible:
+    const: nvidia,tegra264-utc
+
+  reg:
+    items:
+      - description: TX region.
+      - description: RX region.
+
+  reg-names:
+    items:
+      - const: tx
+      - const: rx
+
+  interrupts:
+    maxItems: 1
+
+  tx-threshold:
+    minimum: 1
+    maximum: 128
+
+  rx-threshold:
+    minimum: 1
+    maximum: 128
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - interrupts
+  - tx-threshold
+  - rx-threshold
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    tegra_utc: serial@c4e0000 {
+        compatible = "nvidia,tegra264-utc";
+        reg = <0xc4e0000 0x8000>, <0xc4e8000 0x8000>;
+        reg-names = "tx", "rx";
+        interrupts = <GIC_SPI 514 IRQ_TYPE_LEVEL_HIGH>;
+        tx-threshold = <4>;
+        rx-threshold = <4>;
+    };

Documentation/devicetree/bindings/serial/pl011.yaml

@@ -92,6 +92,9 @@ properties:
       3000ms.
     default: 3000
 
+  power-domains:
+    maxItems: 1
+
   resets:
     maxItems: 1
 

Documentation/devicetree/bindings/serial/samsung_uart.yaml

@@ -42,6 +42,10 @@ properties:
               - samsung,exynosautov9-uart
               - samsung,exynosautov920-uart
           - const: samsung,exynos850-uart
+      - items:
+          - enum:
+              - samsung,exynos7870-uart
+          - const: samsung,exynos8895-uart
 
   reg:
     maxItems: 1

Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml

@@ -13,6 +13,20 @@ allOf:
   - $ref: serial.yaml#
   - $ref: rs485.yaml#
 
+  - if:
+      properties:
+        compatible:
+          items:
+            - enum:
+                - renesas,r9a06g032-uart
+                - renesas,r9a06g033-uart
+            - const: renesas,rzn1-uart
+            - const: snps,dw-apb-uart
+    then:
+      properties:
+        dmas: false
+        dma-names: false
+
   - if:
       properties:
         compatible:
@@ -30,6 +44,12 @@ allOf:
 properties:
   compatible:
     oneOf:
+      - items:
+          - enum:
+              - renesas,r9a06g032-uart
+              - renesas,r9a06g033-uart
+          - const: renesas,rzn1-uart
+          - const: snps,dw-apb-uart
       - items:
           - enum:
               - renesas,r9a06g032-uart
@@ -51,6 +71,7 @@ properties:
               - rockchip,rk3368-uart
               - rockchip,rk3399-uart
               - rockchip,rk3528-uart
+              - rockchip,rk3562-uart
               - rockchip,rk3568-uart
               - rockchip,rk3576-uart
               - rockchip,rk3588-uart

Documentation/devicetree/bindings/serial/sprd-uart.yaml

@@ -17,13 +17,18 @@ properties:
     oneOf:
       - items:
           - enum:
-              - sprd,sc9632-uart
+              - sprd,ums9632-uart
+          - const: sprd,sc9632-uart
+      - items:
+          - enum:
               - sprd,sc9860-uart
               - sprd,sc9863a-uart
               - sprd,ums512-uart
               - sprd,ums9620-uart
           - const: sprd,sc9836-uart
-      - const: sprd,sc9836-uart
+      - enum:
+          - sprd,sc9632-uart
+          - sprd,sc9836-uart
 
   reg:
     maxItems: 1

Documentation/driver-api/serial/driver.rst

@@ -101,6 +101,6 @@ Modem control lines via GPIO
 Some helpers are provided in order to set/get modem control lines via GPIO.
 
 .. kernel-doc:: drivers/tty/serial/serial_mctrl_gpio.c
-   :identifiers: mctrl_gpio_init mctrl_gpio_free mctrl_gpio_to_gpiod
+   :identifiers: mctrl_gpio_init mctrl_gpio_to_gpiod
            mctrl_gpio_set mctrl_gpio_get mctrl_gpio_enable_ms
-           mctrl_gpio_disable_ms
+           mctrl_gpio_disable_ms_sync mctrl_gpio_disable_ms_no_sync

Documentation/driver-api/tty/tty_driver.rst

@@ -25,6 +25,8 @@ freed.
 For reference, both allocation and deallocation functions are explained here in
 detail:
 
+.. kernel-doc:: include/linux/tty_driver.h
+   :identifiers: tty_alloc_driver
 .. kernel-doc:: drivers/tty/tty_io.c
    :identifiers: __tty_alloc_driver tty_driver_kref_put
 
@@ -35,7 +37,7 @@ Here comes the documentation of flags accepted by tty_alloc_driver() (or
 __tty_alloc_driver()):
 
 .. kernel-doc:: include/linux/tty_driver.h
-   :doc: TTY Driver Flags
+   :identifiers: tty_driver_flag
 
 ----
 

Documentation/driver-api/tty/tty_struct.rst

@@ -72,7 +72,7 @@ TTY Struct Flags
 ================
 
 .. kernel-doc:: include/linux/tty.h
-   :doc: TTY Struct Flags
+   :identifiers: tty_struct_flags
 
 TTY Struct Reference
 ====================

MAINTAINERS

@@ -16550,6 +16550,12 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next
 F:	drivers/mtd/nand/
 F:	include/linux/mtd/*nand*.h
 
+NATIONAL INSTRUMENTS SERIAL DRIVER
+M:	Chaitanya Vadrevu <chaitanya.vadrevu@emerson.com>
+L:	linux-serial@vger.kernel.org
+S:	Maintained
+F:	drivers/tty/serial/8250/8250_ni.c
+
 NATIVE INSTRUMENTS USB SOUND INTERFACE DRIVER
 M:	Daniel Mack <zonque@gmail.com>
 L:	linux-sound@vger.kernel.org

arch/alpha/kernel/srmcons.c

@@ -196,40 +196,44 @@ static const struct tty_operations srmcons_ops = {
 static int __init
 srmcons_init(void)
 {
+	struct tty_driver *driver;
+	int err;
+
 	timer_setup(&srmcons_singleton.timer, srmcons_receive_chars, 0);
-	if (srm_is_registered_console) {
-		struct tty_driver *driver;
-		int err;
 
-		driver = tty_alloc_driver(MAX_SRM_CONSOLE_DEVICES, 0);
+	if (!srm_is_registered_console)
-		if (IS_ERR(driver))
+		return -ENODEV;
-			return PTR_ERR(driver);
 
-		tty_port_init(&srmcons_singleton.port);
+	driver = tty_alloc_driver(MAX_SRM_CONSOLE_DEVICES, 0);
+	if (IS_ERR(driver))
+		return PTR_ERR(driver);
 
-		driver->driver_name = "srm";
+	tty_port_init(&srmcons_singleton.port);
-		driver->name = "srm";
-		driver->major = 0; 	/* dynamic */
-		driver->minor_start = 0;
-		driver->type = TTY_DRIVER_TYPE_SYSTEM;
-		driver->subtype = SYSTEM_TYPE_SYSCONS;
-		driver->init_termios = tty_std_termios;
-		tty_set_operations(driver, &srmcons_ops);
-		tty_port_link_device(&srmcons_singleton.port, driver, 0);
-		err = tty_register_driver(driver);
-		if (err) {
-			tty_driver_kref_put(driver);
-			tty_port_destroy(&srmcons_singleton.port);
-			return err;
-		}
-		srmcons_driver = driver;
-	}
 
-	return -ENODEV;
+	driver->driver_name = "srm";
+	driver->name = "srm";
+	driver->major = 0;	/* dynamic */
+	driver->minor_start = 0;
+	driver->type = TTY_DRIVER_TYPE_SYSTEM;
+	driver->subtype = SYSTEM_TYPE_SYSCONS;
+	driver->init_termios = tty_std_termios;
+	tty_set_operations(driver, &srmcons_ops);
+	tty_port_link_device(&srmcons_singleton.port, driver, 0);
+	err = tty_register_driver(driver);
+	if (err)
+		goto err_free_drv;
+
+	srmcons_driver = driver;
+
+	return 0;
+err_free_drv:
+	tty_driver_kref_put(driver);
+	tty_port_destroy(&srmcons_singleton.port);
+
+	return err;
 }
 device_initcall(srmcons_init);
 
-
 /*
  * The console driver
  */

drivers/net/caif/caif_serial.c

@@ -330,7 +330,7 @@ static int ldisc_open(struct tty_struct *tty)
 	ser->tty = tty_kref_get(tty);
 	ser->dev = dev;
 	debugfs_init(ser, tty);
-	tty->receive_room = N_TTY_BUF_SIZE;
+	tty->receive_room = 4096;
 	tty->disc_data = ser;
 	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 	rtnl_lock();

drivers/staging/greybus/uart.c

@@ -948,7 +948,8 @@ static int gb_tty_init(void)
 {
 	int retval = 0;
 
-	gb_tty_driver = tty_alloc_driver(GB_NUM_MINORS, 0);
+	gb_tty_driver = tty_alloc_driver(GB_NUM_MINORS, TTY_DRIVER_REAL_RAW |
+					 TTY_DRIVER_DYNAMIC_DEV);
 	if (IS_ERR(gb_tty_driver)) {
 		pr_err("Can not allocate tty driver\n");
 		retval = -ENOMEM;
@@ -961,7 +962,6 @@ static int gb_tty_init(void)
 	gb_tty_driver->minor_start = 0;
 	gb_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
 	gb_tty_driver->subtype = SERIAL_TYPE_NORMAL;
-	gb_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 	gb_tty_driver->init_termios = tty_std_termios;
 	gb_tty_driver->init_termios.c_cflag = B9600 | CS8 |
 		CREAD | HUPCL | CLOCAL;

drivers/tty/Kconfig

@@ -210,7 +210,7 @@ config SERIAL_NONSTANDARD
 
 config MOXA_INTELLIO
 	tristate "Moxa Intellio support"
-	depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
+	depends on SERIAL_NONSTANDARD && PCI
 	select FW_LOADER
 	help
 	  Say Y here if you have a Moxa Intellio multiport serial card.

drivers/tty/moxa.c

@@ -43,15 +43,6 @@
 #include <linux/ratelimit.h>
 
 #include <asm/io.h>
-#include <linux/uaccess.h>
-
-#define	MOXA			0x400
-#define MOXA_GET_IQUEUE		(MOXA + 1)	/* get input buffered count */
-#define MOXA_GET_OQUEUE		(MOXA + 2)	/* get output buffered count */
-#define MOXA_GETDATACOUNT       (MOXA + 23)
-#define MOXA_GET_IOQUEUE	(MOXA + 27)
-#define MOXA_FLUSH_QUEUE	(MOXA + 28)
-#define MOXA_GETMSTATUS         (MOXA + 65)
 
 /*
  *    System Configuration
@@ -347,8 +338,6 @@
 #define	MX_PARMARK	0xA0
 #define	MX_PARSPACE	0x20
 
-#define MOXA_VERSION		"6.0k"
-
 #define MOXA_FW_HDRLEN		32
 
 #define MOXAMAJOR		172
@@ -357,33 +346,21 @@
 #define MAX_PORTS_PER_BOARD	32	/* Don't change this value */
 #define MAX_PORTS		(MAX_BOARDS * MAX_PORTS_PER_BOARD)
 
-#define MOXA_IS_320(brd) ((brd)->boardType == MOXA_BOARD_C320_ISA || \
+#define MOXA_IS_320(brd)	((brd)->boardType == MOXA_BOARD_C320_PCI)
-		(brd)->boardType == MOXA_BOARD_C320_PCI)
-
-/*
- *    Define the Moxa PCI vendor and device IDs.
- */
-#define MOXA_BUS_TYPE_ISA	0
-#define MOXA_BUS_TYPE_PCI	1
 
 enum {
 	MOXA_BOARD_C218_PCI = 1,
-	MOXA_BOARD_C218_ISA,
 	MOXA_BOARD_C320_PCI,
-	MOXA_BOARD_C320_ISA,
 	MOXA_BOARD_CP204J,
 };
 
 static char *moxa_brdname[] =
 {
 	"C218 Turbo PCI series",
-	"C218 Turbo ISA series",
 	"C320 Turbo PCI series",
-	"C320 Turbo ISA series",
 	"CP-204J series",
 };
 
-#ifdef CONFIG_PCI
 static const struct pci_device_id moxa_pcibrds[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_MOXA, PCI_DEVICE_ID_MOXA_C218),
 		.driver_data = MOXA_BOARD_C218_PCI },
@@ -394,14 +371,12 @@ static const struct pci_device_id moxa_pcibrds[] = {
 	{ 0 }
 };
 MODULE_DEVICE_TABLE(pci, moxa_pcibrds);
-#endif /* CONFIG_PCI */
 
 struct moxa_port;
 
 static struct moxa_board_conf {
 	int boardType;
 	int numPorts;
-	int busType;
 
 	unsigned int ready;
 
@@ -413,19 +388,6 @@ static struct moxa_board_conf {
 	void __iomem *intTable;
 } moxa_boards[MAX_BOARDS];
 
-struct mxser_mstatus {
-	tcflag_t cflag;
-	int cts;
-	int dsr;
-	int ri;
-	int dcd;
-};
-
-struct moxaq_str {
-	int inq;
-	int outq;
-};
-
 struct moxa_port {
 	struct tty_port port;
 	struct moxa_board_conf *board;
@@ -440,12 +402,6 @@ struct moxa_port {
 	u8 lowChkFlag;
 };
 
-struct mon_str {
-	int tick;
-	int rxcnt[MAX_PORTS];
-	int txcnt[MAX_PORTS];
-};
-
 /* statusflags */
 #define TXSTOPPED	1
 #define LOWWAIT 	2
@@ -455,17 +411,11 @@ struct mon_str {
 #define WAKEUP_CHARS		256
 
 static int ttymajor = MOXAMAJOR;
-static struct mon_str moxaLog;
 static unsigned int moxaFuncTout = HZ / 2;
 static unsigned int moxaLowWaterChk;
 static DEFINE_MUTEX(moxa_openlock);
 static DEFINE_SPINLOCK(moxa_lock);
 
-static unsigned long baseaddr[MAX_BOARDS];
-static unsigned int type[MAX_BOARDS];
-static unsigned int numports[MAX_BOARDS];
-static struct tty_port moxa_service_port;
-
 MODULE_AUTHOR("William Chen");
 MODULE_DESCRIPTION("MOXA Intellio Family Multiport Board Device Driver");
 MODULE_LICENSE("GPL");
@@ -473,13 +423,6 @@ MODULE_FIRMWARE("c218tunx.cod");
 MODULE_FIRMWARE("cp204unx.cod");
 MODULE_FIRMWARE("c320tunx.cod");
 
-module_param_array(type, uint, NULL, 0);
-MODULE_PARM_DESC(type, "card type: C218=2, C320=4");
-module_param_hw_array(baseaddr, ulong, ioport, NULL, 0);
-MODULE_PARM_DESC(baseaddr, "base address");
-module_param_array(numports, uint, NULL, 0);
-MODULE_PARM_DESC(numports, "numports (ignored for C218)");
-
 module_param(ttymajor, int, 0);
 
 /*
@@ -583,104 +526,6 @@ static void moxa_low_water_check(void __iomem *ofsAddr)
  * TTY operations
  */
 
-static int moxa_ioctl(struct tty_struct *tty,
-		      unsigned int cmd, unsigned long arg)
-{
-	struct moxa_port *ch = tty->driver_data;
-	void __user *argp = (void __user *)arg;
-	int status, ret = 0;
-
-	if (tty->index == MAX_PORTS) {
-		if (cmd != MOXA_GETDATACOUNT && cmd != MOXA_GET_IOQUEUE &&
-				cmd != MOXA_GETMSTATUS)
-			return -EINVAL;
-	} else if (!ch)
-		return -ENODEV;
-
-	switch (cmd) {
-	case MOXA_GETDATACOUNT:
-		moxaLog.tick = jiffies;
-		if (copy_to_user(argp, &moxaLog, sizeof(moxaLog)))
-			ret = -EFAULT;
-		break;
-	case MOXA_FLUSH_QUEUE:
-		MoxaPortFlushData(ch, arg);
-		break;
-	case MOXA_GET_IOQUEUE: {
-		struct moxaq_str __user *argm = argp;
-		struct moxaq_str tmp;
-		struct moxa_port *p;
-		unsigned int i, j;
-
-		for (i = 0; i < MAX_BOARDS; i++) {
-			p = moxa_boards[i].ports;
-			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {
-				memset(&tmp, 0, sizeof(tmp));
-				spin_lock_bh(&moxa_lock);
-				if (moxa_boards[i].ready) {
-					tmp.inq = MoxaPortRxQueue(p);
-					tmp.outq = MoxaPortTxQueue(p);
-				}
-				spin_unlock_bh(&moxa_lock);
-				if (copy_to_user(argm, &tmp, sizeof(tmp)))
-					return -EFAULT;
-			}
-		}
-		break;
-	} case MOXA_GET_OQUEUE:
-		status = MoxaPortTxQueue(ch);
-		ret = put_user(status, (unsigned long __user *)argp);
-		break;
-	case MOXA_GET_IQUEUE:
-		status = MoxaPortRxQueue(ch);
-		ret = put_user(status, (unsigned long __user *)argp);
-		break;
-	case MOXA_GETMSTATUS: {
-		struct mxser_mstatus __user *argm = argp;
-		struct mxser_mstatus tmp;
-		struct moxa_port *p;
-		unsigned int i, j;
-
-		for (i = 0; i < MAX_BOARDS; i++) {
-			p = moxa_boards[i].ports;
-			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {
-				struct tty_struct *ttyp;
-				memset(&tmp, 0, sizeof(tmp));
-				spin_lock_bh(&moxa_lock);
-				if (!moxa_boards[i].ready) {
-				        spin_unlock_bh(&moxa_lock);
-					goto copy;
-                                }
-
-				status = MoxaPortLineStatus(p);
-				spin_unlock_bh(&moxa_lock);
-
-				if (status & 1)
-					tmp.cts = 1;
-				if (status & 2)
-					tmp.dsr = 1;
-				if (status & 4)
-					tmp.dcd = 1;
-
-				ttyp = tty_port_tty_get(&p->port);
-				if (!ttyp)
-					tmp.cflag = p->cflag;
-				else
-					tmp.cflag = ttyp->termios.c_cflag;
-				tty_kref_put(ttyp);
-copy:
-				if (copy_to_user(argm, &tmp, sizeof(tmp)))
-					return -EFAULT;
-			}
-		}
-		break;
-	}
-	default:
-		ret = -ENOIOCTLCMD;
-	}
-	return ret;
-}
-
 static int moxa_break_ctl(struct tty_struct *tty, int state)
 {
 	struct moxa_port *port = tty->driver_data;
@@ -697,7 +542,6 @@ static const struct tty_operations moxa_ops = {
 	.write_room = moxa_write_room,
 	.flush_buffer = moxa_flush_buffer,
 	.chars_in_buffer = moxa_chars_in_buffer,
-	.ioctl = moxa_ioctl,
 	.set_termios = moxa_set_termios,
 	.stop = moxa_stop,
 	.start = moxa_start,
@@ -725,7 +569,6 @@ static DEFINE_TIMER(moxaTimer, moxa_poll);
 static int moxa_check_fw_model(struct moxa_board_conf *brd, u8 model)
 {
 	switch (brd->boardType) {
-	case MOXA_BOARD_C218_ISA:
 	case MOXA_BOARD_C218_PCI:
 		if (model != 1)
 			goto err;
@@ -769,7 +612,6 @@ static int moxa_load_bios(struct moxa_board_conf *brd, const u8 *buf,
 	msleep(2000);
 
 	switch (brd->boardType) {
-	case MOXA_BOARD_C218_ISA:
 	case MOXA_BOARD_C218_PCI:
 		tmp = readw(baseAddr + C218_key);
 		if (tmp != C218_KeyCode)
@@ -833,7 +675,6 @@ static int moxa_real_load_code(struct moxa_board_conf *brd, const void *ptr,
 
 	switch (brd->boardType) {
 	case MOXA_BOARD_CP204J:
-	case MOXA_BOARD_C218_ISA:
 	case MOXA_BOARD_C218_PCI:
 		key = C218_key;
 		loadbuf = C218_LoadBuf;
@@ -898,15 +739,9 @@ static int moxa_real_load_code(struct moxa_board_conf *brd, const void *ptr,
 		return -EIO;
 
 	if (MOXA_IS_320(brd)) {
-		if (brd->busType == MOXA_BUS_TYPE_PCI) {	/* ASIC board */
+		writew(0x3800, baseAddr + TMS320_PORT1);
-			writew(0x3800, baseAddr + TMS320_PORT1);
+		writew(0x3900, baseAddr + TMS320_PORT2);
-			writew(0x3900, baseAddr + TMS320_PORT2);
+		writew(28499, baseAddr + TMS320_CLOCK);
-			writew(28499, baseAddr + TMS320_CLOCK);
-		} else {
-			writew(0x3200, baseAddr + TMS320_PORT1);
-			writew(0x3400, baseAddr + TMS320_PORT2);
-			writew(19999, baseAddr + TMS320_CLOCK);
-		}
 	}
 	writew(1, baseAddr + Disable_IRQ);
 	writew(0, baseAddr + Magic_no);
@@ -957,7 +792,6 @@ static int moxa_load_code(struct moxa_board_conf *brd, const void *ptr,
 		return retval;
 
 	switch (brd->boardType) {
-	case MOXA_BOARD_C218_ISA:
 	case MOXA_BOARD_C218_PCI:
 	case MOXA_BOARD_CP204J:
 		port = brd->ports;
@@ -1141,7 +975,6 @@ static int moxa_init_board(struct moxa_board_conf *brd, struct device *dev)
 	}
 
 	switch (brd->boardType) {
-	case MOXA_BOARD_C218_ISA:
 	case MOXA_BOARD_C218_PCI:
 		file = "c218tunx.cod";
 		break;
@@ -1227,7 +1060,6 @@ static void moxa_board_deinit(struct moxa_board_conf *brd)
 	kfree(brd->ports);
 }
 
-#ifdef CONFIG_PCI
 static int moxa_pci_probe(struct pci_dev *pdev,
 		const struct pci_device_id *ent)
 {
@@ -1270,7 +1102,6 @@ static int moxa_pci_probe(struct pci_dev *pdev,
 
 	board->boardType = board_type;
 	switch (board_type) {
-	case MOXA_BOARD_C218_ISA:
 	case MOXA_BOARD_C218_PCI:
 		board->numPorts = 8;
 		break;
@@ -1282,7 +1113,6 @@ static int moxa_pci_probe(struct pci_dev *pdev,
 		board->numPorts = 0;
 		break;
 	}
-	board->busType = MOXA_BUS_TYPE_PCI;
 
 	retval = moxa_init_board(board, &pdev->dev);
 	if (retval)
@@ -1318,21 +1148,12 @@ static struct pci_driver moxa_pci_driver = {
 	.probe = moxa_pci_probe,
 	.remove = moxa_pci_remove
 };
-#endif /* CONFIG_PCI */
 
 static int __init moxa_init(void)
 {
-	unsigned int isabrds = 0;
 	int retval = 0;
-	struct moxa_board_conf *brd = moxa_boards;
-	unsigned int i;
 
-	printk(KERN_INFO "MOXA Intellio family driver version %s\n",
+	moxaDriver = tty_alloc_driver(MAX_PORTS,
-			MOXA_VERSION);
-
-	tty_port_init(&moxa_service_port);
-
-	moxaDriver = tty_alloc_driver(MAX_PORTS + 1,
 			TTY_DRIVER_REAL_RAW |
 			TTY_DRIVER_DYNAMIC_DEV);
 	if (IS_ERR(moxaDriver))
@@ -1348,8 +1169,6 @@ static int __init moxa_init(void)
 	moxaDriver->init_termios.c_ispeed = 9600;
 	moxaDriver->init_termios.c_ospeed = 9600;
 	tty_set_operations(moxaDriver, &moxa_ops);
-	/* Having one more port only for ioctls is ugly */
-	tty_port_link_device(&moxa_service_port, moxaDriver, MAX_PORTS);
 
 	if (tty_register_driver(moxaDriver)) {
 		printk(KERN_ERR "can't register MOXA Smartio tty driver!\n");
@@ -1357,64 +1176,16 @@ static int __init moxa_init(void)
 		return -1;
 	}
 
-	/* Find the boards defined from module args. */
-
-	for (i = 0; i < MAX_BOARDS; i++) {
-		if (!baseaddr[i])
-			break;
-		if (type[i] == MOXA_BOARD_C218_ISA ||
-				type[i] == MOXA_BOARD_C320_ISA) {
-			pr_debug("Moxa board %2d: %s board(baseAddr=%lx)\n",
-					isabrds + 1, moxa_brdname[type[i] - 1],
-					baseaddr[i]);
-			brd->boardType = type[i];
-			brd->numPorts = type[i] == MOXA_BOARD_C218_ISA ? 8 :
-					numports[i];
-			brd->busType = MOXA_BUS_TYPE_ISA;
-			brd->basemem = ioremap(baseaddr[i], 0x4000);
-			if (!brd->basemem) {
-				printk(KERN_ERR "MOXA: can't remap %lx\n",
-						baseaddr[i]);
-				continue;
-			}
-			if (moxa_init_board(brd, NULL)) {
-				iounmap(brd->basemem);
-				brd->basemem = NULL;
-				continue;
-			}
-
-			printk(KERN_INFO "MOXA isa board found at 0x%.8lx and "
-					"ready (%u ports, firmware loaded)\n",
-					baseaddr[i], brd->numPorts);
-
-			brd++;
-			isabrds++;
-		}
-	}
-
-#ifdef CONFIG_PCI
 	retval = pci_register_driver(&moxa_pci_driver);
-	if (retval) {
+	if (retval)
 		printk(KERN_ERR "Can't register MOXA pci driver!\n");
-		if (isabrds)
-			retval = 0;
-	}
-#endif
 
 	return retval;
 }
 
 static void __exit moxa_exit(void)
 {
-	unsigned int i;
-
-#ifdef CONFIG_PCI
 	pci_unregister_driver(&moxa_pci_driver);
-#endif
-
-	for (i = 0; i < MAX_BOARDS; i++) /* ISA boards */
-		if (moxa_boards[i].ready)
-			moxa_board_deinit(&moxa_boards[i]);
 
 	del_timer_sync(&moxaTimer);
 
@@ -1457,9 +1228,6 @@ static int moxa_open(struct tty_struct *tty, struct file *filp)
 	int port;
 
 	port = tty->index;
-	if (port == MAX_PORTS) {
-		return capable(CAP_SYS_ADMIN) ? 0 : -EPERM;
-	}
 	if (mutex_lock_interruptible(&moxa_openlock))
 		return -ERESTARTSYS;
 	brd = &moxa_boards[port / MAX_PORTS_PER_BOARD];
@@ -2182,7 +1950,6 @@ static ssize_t MoxaPortWriteData(struct tty_struct *tty, const u8 *buffer,
 	c = (head > tail) ? (head - tail - 1) : (head - tail + tx_mask);
 	if (c > len)
 		c = len;
-	moxaLog.txcnt[port->port.tty->index] += c;
 	total = c;
 	if (spage == epage) {
 		bufhead = readw(ofsAddr + Ofs_txb);
@@ -2224,7 +1991,6 @@ static ssize_t MoxaPortWriteData(struct tty_struct *tty, const u8 *buffer,
 
 static int MoxaPortReadData(struct moxa_port *port)
 {
-	struct tty_struct *tty = port->port.tty;
 	void __iomem *baseAddr, *ofsAddr, *ofs;
 	u8 *dst;
 	unsigned int count, len, total;
@@ -2243,7 +2009,6 @@ static int MoxaPortReadData(struct moxa_port *port)
 		return 0;
 
 	total = count;
-	moxaLog.rxcnt[tty->index] += total;
 	if (spage == epage) {
 		bufhead = readw(ofsAddr + Ofs_rxb);
 		writew(spage, baseAddr + Control_reg);
@@ -2331,8 +2096,6 @@ static int moxa_get_serial_info(struct tty_struct *tty,
 {
 	struct moxa_port *info = tty->driver_data;
 
-	if (tty->index == MAX_PORTS)
-		return -EINVAL;
 	if (!info)
 		return -ENODEV;
 	mutex_lock(&info->port.mutex);
@@ -2352,8 +2115,6 @@ static int moxa_set_serial_info(struct tty_struct *tty,
 	struct moxa_port *info = tty->driver_data;
 	unsigned int close_delay;
 
-	if (tty->index == MAX_PORTS)
-		return -EINVAL;
 	if (!info)
 		return -ENODEV;
 

drivers/tty/n_tty.c

@@ -56,6 +56,8 @@
  */
 #define WAKEUP_CHARS 256
 
+#define N_TTY_BUF_SIZE 4096
+
 /*
  * This defines the low- and high-watermarks for throttling and
  * unthrottling the TTY driver.  These watermarks are used for
@@ -79,14 +81,6 @@
 #define ECHO_BLOCK		256
 #define ECHO_DISCARD_WATERMARK	N_TTY_BUF_SIZE - (ECHO_BLOCK + 32)
 
-
-#undef N_TTY_TRACE
-#ifdef N_TTY_TRACE
-# define n_tty_trace(f, args...)	trace_printk(f, ##args)
-#else
-# define n_tty_trace(f, args...)	no_printk(f, ##args)
-#endif
-
 struct n_tty_data {
 	/* producer-published */
 	size_t read_head;
@@ -486,18 +480,13 @@ static int do_output_char(u8 c, struct tty_struct *tty, int space)
 static int process_output(u8 c, struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	int	space, retval;
 
-	mutex_lock(&ldata->output_lock);
+	guard(mutex)(&ldata->output_lock);
 
-	space = tty_write_room(tty);
+	if (do_output_char(c, tty, tty_write_room(tty)) < 0)
-	retval = do_output_char(c, tty, space);
-
-	mutex_unlock(&ldata->output_lock);
-	if (retval < 0)
 		return -1;
-	else
+
-		return 0;
+	return 0;
 }
 
 /**
@@ -522,17 +511,15 @@ static ssize_t process_output_block(struct tty_struct *tty,
 				    const u8 *buf, unsigned int nr)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	int	space;
+	unsigned int space, i;
-	int	i;
 	const u8 *cp;
 
-	mutex_lock(&ldata->output_lock);
+	guard(mutex)(&ldata->output_lock);
 
 	space = tty_write_room(tty);
-	if (space <= 0) {
+	if (space == 0)
-		mutex_unlock(&ldata->output_lock);
+		return 0;
-		return space;
+
-	}
 	if (nr > space)
 		nr = space;
 
@@ -544,18 +531,18 @@ static ssize_t process_output_block(struct tty_struct *tty,
 			if (O_ONLRET(tty))
 				ldata->column = 0;
 			if (O_ONLCR(tty))
-				goto break_out;
+				goto do_write;
 			ldata->canon_column = ldata->column;
 			break;
 		case '\r':
 			if (O_ONOCR(tty) && ldata->column == 0)
-				goto break_out;
+				goto do_write;
 			if (O_OCRNL(tty))
-				goto break_out;
+				goto do_write;
 			ldata->canon_column = ldata->column = 0;
 			break;
 		case '\t':
-			goto break_out;
+			goto do_write;
 		case '\b':
 			if (ldata->column > 0)
 				ldata->column--;
@@ -563,18 +550,15 @@ static ssize_t process_output_block(struct tty_struct *tty,
 		default:
 			if (!iscntrl(c)) {
 				if (O_OLCUC(tty))
-					goto break_out;
+					goto do_write;
 				if (!is_continuation(c, tty))
 					ldata->column++;
 			}
 			break;
 		}
 	}
-break_out:
+do_write:
-	i = tty->ops->write(tty, buf, i);
+	return tty->ops->write(tty, buf, i);
-
-	mutex_unlock(&ldata->output_lock);
-	return i;
 }
 
 static int n_tty_process_echo_ops(struct tty_struct *tty, size_t *tail,
@@ -696,7 +680,7 @@ static int n_tty_process_echo_ops(struct tty_struct *tty, size_t *tail,
 static size_t __process_echoes(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	int	space, old_space;
+	unsigned int space, old_space;
 	size_t tail;
 	u8 c;
 
@@ -2034,9 +2018,6 @@ static bool canon_copy_from_read_buf(const struct tty_struct *tty, u8 **kbp,
 	tail = MASK(ldata->read_tail);
 	size = min_t(size_t, tail + n, N_TTY_BUF_SIZE);
 
-	n_tty_trace("%s: nr:%zu tail:%zu n:%zu size:%zu\n",
-		    __func__, *nr, tail, n, size);
-
 	eol = find_next_bit(ldata->read_flags, size, tail);
 	more = n - (size - tail);
 	if (eol == N_TTY_BUF_SIZE && more) {
@@ -2054,9 +2035,6 @@ static bool canon_copy_from_read_buf(const struct tty_struct *tty, u8 **kbp,
 	if (!found || read_buf(ldata, eol) != __DISABLED_CHAR)
 		n = c;
 
-	n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n",
-		    __func__, eol, found, n, c, tail, more);
-
 	tty_copy(tty, *kbp, tail, n);
 	*kbp += n;
 	*nr -= n;
@@ -2133,6 +2111,66 @@ static int job_control(struct tty_struct *tty, struct file *file)
 	return __tty_check_change(tty, SIGTTIN);
 }
 
+/*
+ * We still hold the atomic_read_lock and the termios_rwsem, and can just
+ * continue to copy data.
+ */
+static ssize_t n_tty_continue_cookie(struct tty_struct *tty, u8 *kbuf,
+				   size_t nr, void **cookie)
+{
+	struct n_tty_data *ldata = tty->disc_data;
+	u8 *kb = kbuf;
+
+	if (ldata->icanon && !L_EXTPROC(tty)) {
+		/*
+		 * If we have filled the user buffer, see if we should skip an
+		 * EOF character before releasing the lock and returning done.
+		 */
+		if (!nr)
+			canon_skip_eof(ldata);
+		else if (canon_copy_from_read_buf(tty, &kb, &nr))
+			return kb - kbuf;
+	} else {
+		if (copy_from_read_buf(tty, &kb, &nr))
+			return kb - kbuf;
+	}
+
+	/* No more data - release locks and stop retries */
+	n_tty_kick_worker(tty);
+	n_tty_check_unthrottle(tty);
+	up_read(&tty->termios_rwsem);
+	mutex_unlock(&ldata->atomic_read_lock);
+	*cookie = NULL;
+
+	return kb - kbuf;
+}
+
+static int n_tty_wait_for_input(struct tty_struct *tty, struct file *file,
+				struct wait_queue_entry *wait, long *timeout)
+{
+	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+		return -EIO;
+	if (tty_hung_up_p(file))
+		return 0;
+	/*
+	 * Abort readers for ttys which never actually get hung up.
+	 * See __tty_hangup().
+	 */
+	if (test_bit(TTY_HUPPING, &tty->flags))
+		return 0;
+	if (!*timeout)
+		return 0;
+	if (tty_io_nonblock(tty, file))
+		return -EAGAIN;
+	if (signal_pending(current))
+		return -ERESTARTSYS;
+
+	up_read(&tty->termios_rwsem);
+	*timeout = wait_woken(wait, TASK_INTERRUPTIBLE, *timeout);
+	down_read(&tty->termios_rwsem);
+
+	return 1;
+}
 
 /**
  * n_tty_read		-	read function for tty
@@ -2166,36 +2204,9 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf,
 	bool packet;
 	size_t old_tail;
 
-	/*
+	/* Is this a continuation of a read started earlier? */
-	 * Is this a continuation of a read started earler?
+	if (*cookie)
-	 *
+		return n_tty_continue_cookie(tty, kbuf, nr, cookie);
-	 * If so, we still hold the atomic_read_lock and the
-	 * termios_rwsem, and can just continue to copy data.
-	 */
-	if (*cookie) {
-		if (ldata->icanon && !L_EXTPROC(tty)) {
-			/*
-			 * If we have filled the user buffer, see
-			 * if we should skip an EOF character before
-			 * releasing the lock and returning done.
-			 */
-			if (!nr)
-				canon_skip_eof(ldata);
-			else if (canon_copy_from_read_buf(tty, &kb, &nr))
-				return kb - kbuf;
-		} else {
-			if (copy_from_read_buf(tty, &kb, &nr))
-				return kb - kbuf;
-		}
-
-		/* No more data - release locks and stop retries */
-		n_tty_kick_worker(tty);
-		n_tty_check_unthrottle(tty);
-		up_read(&tty->termios_rwsem);
-		mutex_unlock(&ldata->atomic_read_lock);
-		*cookie = NULL;
-		return kb - kbuf;
-	}
 
 	retval = job_control(tty, file);
 	if (retval < 0)
@@ -2250,34 +2261,12 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf,
 			tty_buffer_flush_work(tty->port);
 			down_read(&tty->termios_rwsem);
 			if (!input_available_p(tty, 0)) {
-				if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+				int ret = n_tty_wait_for_input(tty, file, &wait,
-					retval = -EIO;
+							       &timeout);
+				if (ret <= 0) {
+					retval = ret;
 					break;
 				}
-				if (tty_hung_up_p(file))
-					break;
-				/*
-				 * Abort readers for ttys which never actually
-				 * get hung up.  See __tty_hangup().
-				 */
-				if (test_bit(TTY_HUPPING, &tty->flags))
-					break;
-				if (!timeout)
-					break;
-				if (tty_io_nonblock(tty, file)) {
-					retval = -EAGAIN;
-					break;
-				}
-				if (signal_pending(current)) {
-					retval = -ERESTARTSYS;
-					break;
-				}
-				up_read(&tty->termios_rwsem);
-
-				timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
-						timeout);
-
-				down_read(&tty->termios_rwsem);
 				continue;
 			}
 		}
@@ -2292,21 +2281,8 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf,
 				nr--;
 			}
 
-			/*
+			if (copy_from_read_buf(tty, &kb, &nr) && kb - kbuf >= minimum)
-			 * Copy data, and if there is more to be had
+				goto more_to_be_read;
-			 * and we have nothing more to wait for, then
-			 * let's mark us for retries.
-			 *
-			 * NOTE! We return here with both the termios_sem
-			 * and atomic_read_lock still held, the retries
-			 * will release them when done.
-			 */
-			if (copy_from_read_buf(tty, &kb, &nr) && kb - kbuf >= minimum) {
-more_to_be_read:
-				remove_wait_queue(&tty->read_wait, &wait);
-				*cookie = cookie;
-				return kb - kbuf;
-			}
 		}
 
 		n_tty_check_unthrottle(tty);
@@ -2333,6 +2309,18 @@ more_to_be_read:
 		retval = kb - kbuf;
 
 	return retval;
+more_to_be_read:
+	/*
+	 * There is more to be had and we have nothing more to wait for, so
+	 * let's mark us for retries.
+	 *
+	 * NOTE! We return here with both the termios_sem and atomic_read_lock
+	 * still held, the retries will release them when done.
+	 */
+	remove_wait_queue(&tty->read_wait, &wait);
+	*cookie = cookie;
+
+	return kb - kbuf;
 }
 
 /**

drivers/tty/serdev/core.c

@@ -316,17 +316,6 @@ void serdev_device_write_flush(struct serdev_device *serdev)
 }
 EXPORT_SYMBOL_GPL(serdev_device_write_flush);
 
-int serdev_device_write_room(struct serdev_device *serdev)
-{
-	struct serdev_controller *ctrl = serdev->ctrl;
-
-	if (!ctrl || !ctrl->ops->write_room)
-		return 0;
-
-	return serdev->ctrl->ops->write_room(ctrl);
-}
-EXPORT_SYMBOL_GPL(serdev_device_write_room);
-
 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
 {
 	struct serdev_controller *ctrl = serdev->ctrl;

drivers/tty/serdev/serdev-ttyport.c

@@ -92,14 +92,6 @@ static void ttyport_write_flush(struct serdev_controller *ctrl)
 	tty_driver_flush_buffer(tty);
 }
 
-static int ttyport_write_room(struct serdev_controller *ctrl)
-{
-	struct serport *serport = serdev_controller_get_drvdata(ctrl);
-	struct tty_struct *tty = serport->tty;
-
-	return tty_write_room(tty);
-}
-
 static int ttyport_open(struct serdev_controller *ctrl)
 {
 	struct serport *serport = serdev_controller_get_drvdata(ctrl);
@@ -259,7 +251,6 @@ static int ttyport_break_ctl(struct serdev_controller *ctrl, unsigned int break_
 static const struct serdev_controller_ops ctrl_ops = {
 	.write_buf = ttyport_write_buf,
 	.write_flush = ttyport_write_flush,
-	.write_room = ttyport_write_room,
 	.open = ttyport_open,
 	.close = ttyport_close,
 	.set_flow_control = ttyport_set_flow_control,

drivers/tty/serial/8250/8250_dma.c

@@ -162,7 +162,7 @@ void serial8250_tx_dma_flush(struct uart_8250_port *p)
 	 */
 	dma->tx_size = 0;
 
-	dmaengine_terminate_async(dma->rxchan);
+	dmaengine_terminate_async(dma->txchan);
 }
 
 int serial8250_rx_dma(struct uart_8250_port *p)

drivers/tty/serial/8250/8250_dw.c

@@ -107,11 +107,23 @@ static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
 	return value;
 }
 
+/*
+ * This function is being called as part of the uart_port::serial_out()
+ * routine. Hence, it must not call serial_port_out() or serial_out()
+ * against the modified registers here, i.e. LCR.
+ */
 static void dw8250_force_idle(struct uart_port *p)
 {
 	struct uart_8250_port *up = up_to_u8250p(p);
 	unsigned int lsr;
 
+	/*
+	 * The following call currently performs serial_out()
+	 * against the FCR register. Because it differs to LCR
+	 * there will be no infinite loop, but if it ever gets
+	 * modified, we might need a new custom version of it
+	 * that avoids infinite recursion.
+	 */
 	serial8250_clear_and_reinit_fifos(up);
 
 	/*
@@ -120,14 +132,19 @@ static void dw8250_force_idle(struct uart_port *p)
 	 * enabled.
 	 */
 	if (up->fcr & UART_FCR_ENABLE_FIFO) {
-		lsr = p->serial_in(p, UART_LSR);
+		lsr = serial_port_in(p, UART_LSR);
 		if (!(lsr & UART_LSR_DR))
 			return;
 	}
 
-	(void)p->serial_in(p, UART_RX);
+	serial_port_in(p, UART_RX);
 }
 
+/*
+ * This function is being called as part of the uart_port::serial_out()
+ * routine. Hence, it must not call serial_port_out() or serial_out()
+ * against the modified registers here, i.e. LCR.
+ */
 static void dw8250_check_lcr(struct uart_port *p, int offset, int value)
 {
 	struct dw8250_data *d = to_dw8250_data(p->private_data);
@@ -139,7 +156,7 @@ static void dw8250_check_lcr(struct uart_port *p, int offset, int value)
 
 	/* Make sure LCR write wasn't ignored */
 	while (tries--) {
-		unsigned int lcr = p->serial_in(p, offset);
+		unsigned int lcr = serial_port_in(p, offset);
 
 		if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
 			return;
@@ -260,7 +277,7 @@ static int dw8250_handle_irq(struct uart_port *p)
 {
 	struct uart_8250_port *up = up_to_u8250p(p);
 	struct dw8250_data *d = to_dw8250_data(p->private_data);
-	unsigned int iir = p->serial_in(p, UART_IIR);
+	unsigned int iir = serial_port_in(p, UART_IIR);
 	bool rx_timeout = (iir & 0x3f) == UART_IIR_RX_TIMEOUT;
 	unsigned int quirks = d->pdata->quirks;
 	unsigned int status;
@@ -281,7 +298,7 @@ static int dw8250_handle_irq(struct uart_port *p)
 		status = serial_lsr_in(up);
 
 		if (!(status & (UART_LSR_DR | UART_LSR_BI)))
-			(void) p->serial_in(p, UART_RX);
+			serial_port_in(p, UART_RX);
 
 		uart_port_unlock_irqrestore(p, flags);
 	}
@@ -303,7 +320,7 @@ static int dw8250_handle_irq(struct uart_port *p)
 
 	if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
 		/* Clear the USR */
-		(void)p->serial_in(p, d->pdata->usr_reg);
+		serial_port_in(p, d->pdata->usr_reg);
 
 		return 1;
 	}
@@ -390,7 +407,7 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
 static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
 {
 	struct uart_8250_port *up = up_to_u8250p(p);
-	unsigned int mcr = p->serial_in(p, UART_MCR);
+	unsigned int mcr = serial_port_in(p, UART_MCR);
 
 	if (up->capabilities & UART_CAP_IRDA) {
 		if (termios->c_line == N_IRDA)
@@ -398,7 +415,7 @@ static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
 		else
 			mcr &= ~DW_UART_MCR_SIRE;
 
-		p->serial_out(p, UART_MCR, mcr);
+		serial_port_out(p, UART_MCR, mcr);
 	}
 	serial8250_do_set_ldisc(p, termios);
 }
@@ -421,6 +438,18 @@ static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
 	return param == chan->device->dev;
 }
 
+static void dw8250_setup_dma_filter(struct uart_port *p, struct dw8250_data *data)
+{
+	/* Platforms with iDMA 64-bit */
+	if (platform_get_resource_byname(to_platform_device(p->dev), IORESOURCE_MEM, "lpss_priv")) {
+		data->data.dma.rx_param = p->dev->parent;
+		data->data.dma.tx_param = p->dev->parent;
+		data->data.dma.fn = dw8250_idma_filter;
+	} else {
+		data->data.dma.fn = dw8250_fallback_dma_filter;
+	}
+}
+
 static u32 dw8250_rzn1_get_dmacr_burst(int max_burst)
 {
 	if (max_burst >= 8)
@@ -459,8 +488,8 @@ static void dw8250_prepare_rx_dma(struct uart_8250_port *p)
 
 static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 {
-	unsigned int quirks = data->pdata ? data->pdata->quirks : 0;
+	unsigned int quirks = data->pdata->quirks;
-	u32 cpr_value = data->pdata ? data->pdata->cpr_value : 0;
+	u32 cpr_value = data->pdata->cpr_value;
 
 	if (quirks & DW_UART_QUIRK_CPR_VALUE)
 		data->data.cpr_value = cpr_value;
@@ -491,14 +520,6 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 		p->serial_in = dw8250_serial_in32;
 		data->uart_16550_compatible = true;
 	}
-
-	/* Platforms with iDMA 64-bit */
-	if (platform_get_resource_byname(to_platform_device(p->dev),
-					 IORESOURCE_MEM, "lpss_priv")) {
-		data->data.dma.rx_param = p->dev->parent;
-		data->data.dma.tx_param = p->dev->parent;
-		data->data.dma.fn = dw8250_idma_filter;
-	}
 }
 
 static void dw8250_reset_control_assert(void *data)
@@ -520,7 +541,6 @@ static int dw8250_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, -EINVAL, "no registers defined\n");
 
 	spin_lock_init(&p->lock);
-	p->handle_irq	= dw8250_handle_irq;
 	p->pm		= dw8250_do_pm;
 	p->type		= PORT_8250;
 	p->flags	= UPF_FIXED_PORT;
@@ -532,13 +552,8 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (!data)
 		return -ENOMEM;
 
-	data->data.dma.fn = dw8250_fallback_dma_filter;
-	data->pdata = device_get_match_data(p->dev);
 	p->private_data = &data->data;
 
-	data->uart_16550_compatible = device_property_read_bool(dev,
-						"snps,uart-16550-compatible");
-
 	p->mapbase = regs->start;
 	p->mapsize = resource_size(regs);
 
@@ -626,11 +641,19 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
-	dw8250_quirks(p, data);
+	data->uart_16550_compatible = device_property_read_bool(dev, "snps,uart-16550-compatible");
+
+	data->pdata = device_get_match_data(p->dev);
+	if (data->pdata)
+		dw8250_quirks(p, data);
 
 	/* If the Busy Functionality is not implemented, don't handle it */
 	if (data->uart_16550_compatible)
 		p->handle_irq = NULL;
+	else if (data->pdata)
+		p->handle_irq = dw8250_handle_irq;
+
+	dw8250_setup_dma_filter(p, data);
 
 	if (!data->skip_autocfg)
 		dw8250_setup_port(p);

drivers/tty/serial/8250/8250_fsl.c

@@ -32,7 +32,7 @@ int fsl8250_handle_irq(struct uart_port *port)
 
 	uart_port_lock_irqsave(&up->port, &flags);
 
-	iir = port->serial_in(port, UART_IIR);
+	iir = serial_port_in(port, UART_IIR);
 	if (iir & UART_IIR_NO_INT) {
 		uart_port_unlock_irqrestore(&up->port, flags);
 		return 0;
@@ -54,12 +54,12 @@ int fsl8250_handle_irq(struct uart_port *port)
 	if (unlikely((iir & UART_IIR_ID) == UART_IIR_RLSI &&
 		     (up->lsr_saved_flags & UART_LSR_BI))) {
 		up->lsr_saved_flags &= ~UART_LSR_BI;
-		port->serial_in(port, UART_RX);
+		serial_port_in(port, UART_RX);
 		uart_port_unlock_irqrestore(&up->port, flags);
 		return 1;
 	}
 
-	lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR);
+	lsr = orig_lsr = serial_port_in(port, UART_LSR);
 
 	/* Process incoming characters first */
 	if ((lsr & (UART_LSR_DR | UART_LSR_BI)) &&
@@ -71,7 +71,7 @@ int fsl8250_handle_irq(struct uart_port *port)
 	if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {
 		unsigned long delay;
 
-		up->ier = port->serial_in(port, UART_IER);
+		up->ier = serial_port_in(port, UART_IER);
 		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
 			port->ops->stop_rx(port);
 		} else {

drivers/tty/serial/8250/8250_ni.c

@@ -0,0 +1,461 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * NI 16550 UART Driver
+ *
+ * The National Instruments (NI) 16550 is a UART that is compatible with the
+ * TL16C550C and OX16C950B register interfaces, but has additional functions
+ * for RS-485 transceiver control. This driver implements support for the
+ * additional functionality on top of the standard serial8250 core.
+ *
+ * Copyright 2012-2023 National Instruments Corporation
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/clk.h>
+
+#include "8250.h"
+
+/* Extra bits in UART_ACR */
+#define NI16550_ACR_AUTO_DTR_EN			BIT(4)
+
+/* TFS - TX FIFO Size */
+#define NI16550_TFS_OFFSET	0x0C
+/* RFS - RX FIFO Size */
+#define NI16550_RFS_OFFSET	0x0D
+
+/* PMR - Port Mode Register */
+#define NI16550_PMR_OFFSET	0x0E
+/* PMR[1:0] - Port Capabilities */
+#define NI16550_PMR_CAP_MASK		GENMASK(1, 0)
+#define NI16550_PMR_NOT_IMPL		FIELD_PREP(NI16550_PMR_CAP_MASK, 0) /* not implemented */
+#define NI16550_PMR_CAP_RS232		FIELD_PREP(NI16550_PMR_CAP_MASK, 1) /* RS-232 capable */
+#define NI16550_PMR_CAP_RS485		FIELD_PREP(NI16550_PMR_CAP_MASK, 2) /* RS-485 capable */
+#define NI16550_PMR_CAP_DUAL		FIELD_PREP(NI16550_PMR_CAP_MASK, 3) /* dual-port */
+/* PMR[4] - Interface Mode */
+#define NI16550_PMR_MODE_MASK		GENMASK(4, 4)
+#define NI16550_PMR_MODE_RS232		FIELD_PREP(NI16550_PMR_MODE_MASK, 0) /* currently 232 */
+#define NI16550_PMR_MODE_RS485		FIELD_PREP(NI16550_PMR_MODE_MASK, 1) /* currently 485 */
+
+/* PCR - Port Control Register */
+/*
+ * Wire Mode      | Tx enabled?          | Rx enabled?
+ * ---------------|----------------------|--------------------------
+ * PCR_RS422      | Always               | Always
+ * PCR_ECHO_RS485 | When DTR asserted    | Always
+ * PCR_DTR_RS485  | When DTR asserted    | Disabled when TX enabled
+ * PCR_AUTO_RS485 | When data in TX FIFO | Disabled when TX enabled
+ */
+#define NI16550_PCR_OFFSET	0x0F
+#define NI16550_PCR_WIRE_MODE_MASK		GENMASK(1, 0)
+#define NI16550_PCR_RS422			FIELD_PREP(NI16550_PCR_WIRE_MODE_MASK, 0)
+#define NI16550_PCR_ECHO_RS485			FIELD_PREP(NI16550_PCR_WIRE_MODE_MASK, 1)
+#define NI16550_PCR_DTR_RS485			FIELD_PREP(NI16550_PCR_WIRE_MODE_MASK, 2)
+#define NI16550_PCR_AUTO_RS485			FIELD_PREP(NI16550_PCR_WIRE_MODE_MASK, 3)
+#define NI16550_PCR_TXVR_ENABLE_BIT		BIT(3)
+#define NI16550_PCR_RS485_TERMINATION_BIT	BIT(6)
+
+/* flags for ni16550_device_info */
+#define NI_HAS_PMR		BIT(0)
+
+struct ni16550_device_info {
+	u32 uartclk;
+	u8 prescaler;
+	u8 flags;
+};
+
+struct ni16550_data {
+	int line;
+	struct clk *clk;
+};
+
+static int ni16550_enable_transceivers(struct uart_port *port)
+{
+	u8 pcr;
+
+	pcr = port->serial_in(port, NI16550_PCR_OFFSET);
+	pcr |= NI16550_PCR_TXVR_ENABLE_BIT;
+	dev_dbg(port->dev, "enable transceivers: write pcr: 0x%02x\n", pcr);
+	port->serial_out(port, NI16550_PCR_OFFSET, pcr);
+
+	return 0;
+}
+
+static int ni16550_disable_transceivers(struct uart_port *port)
+{
+	u8 pcr;
+
+	pcr = port->serial_in(port, NI16550_PCR_OFFSET);
+	pcr &= ~NI16550_PCR_TXVR_ENABLE_BIT;
+	dev_dbg(port->dev, "disable transceivers: write pcr: 0x%02x\n", pcr);
+	port->serial_out(port, NI16550_PCR_OFFSET, pcr);
+
+	return 0;
+}
+
+static int ni16550_rs485_config(struct uart_port *port,
+				struct ktermios *termios,
+				struct serial_rs485 *rs485)
+{
+	struct uart_8250_port *up = container_of(port, struct uart_8250_port, port);
+	u8 pcr;
+
+	pcr = serial_in(up, NI16550_PCR_OFFSET);
+	pcr &= ~NI16550_PCR_WIRE_MODE_MASK;
+
+	if ((rs485->flags & SER_RS485_MODE_RS422) ||
+	    !(rs485->flags & SER_RS485_ENABLED)) {
+		/* RS-422 */
+		pcr |= NI16550_PCR_RS422;
+		up->acr &= ~NI16550_ACR_AUTO_DTR_EN;
+	} else {
+		/* RS-485 2-wire Auto */
+		pcr |= NI16550_PCR_AUTO_RS485;
+		up->acr |= NI16550_ACR_AUTO_DTR_EN;
+	}
+
+	dev_dbg(port->dev, "config rs485: write pcr: 0x%02x, acr: %02x\n", pcr, up->acr);
+	serial_out(up, NI16550_PCR_OFFSET, pcr);
+	serial_icr_write(up, UART_ACR, up->acr);
+
+	return 0;
+}
+
+static bool is_pmr_rs232_mode(struct uart_8250_port *up)
+{
+	u8 pmr = serial_in(up, NI16550_PMR_OFFSET);
+	u8 pmr_mode = pmr & NI16550_PMR_MODE_MASK;
+	u8 pmr_cap = pmr & NI16550_PMR_CAP_MASK;
+
+	/*
+	 * If the PMR is not implemented, then by default NI UARTs are
+	 * connected to RS-485 transceivers
+	 */
+	if (pmr_cap == NI16550_PMR_NOT_IMPL)
+		return false;
+
+	if (pmr_cap == NI16550_PMR_CAP_DUAL)
+		/*
+		 * If the port is dual-mode capable, then read the mode bit
+		 * to know the current mode
+		 */
+		return pmr_mode == NI16550_PMR_MODE_RS232;
+	/*
+	 * If it is not dual-mode capable, then decide based on the
+	 * capability
+	 */
+	return pmr_cap == NI16550_PMR_CAP_RS232;
+}
+
+static void ni16550_config_prescaler(struct uart_8250_port *up,
+				     u8 prescaler)
+{
+	/*
+	 * Page in the Enhanced Mode Registers
+	 * Sets EFR[4] for Enhanced Mode.
+	 */
+	u8 lcr_value;
+	u8 efr_value;
+
+	lcr_value = serial_in(up, UART_LCR);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+	efr_value = serial_in(up, UART_EFR);
+	efr_value |= UART_EFR_ECB;
+
+	serial_out(up, UART_EFR, efr_value);
+
+	/* Page out the Enhanced Mode Registers */
+	serial_out(up, UART_LCR, lcr_value);
+
+	/* Set prescaler to CPR register. */
+	serial_out(up, UART_SCR, UART_CPR);
+	serial_out(up, UART_ICR, prescaler);
+}
+
+static const struct serial_rs485 ni16550_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_MODE_RS422 | SER_RS485_RTS_ON_SEND |
+		 SER_RS485_RTS_AFTER_SEND,
+	/*
+	 * delay_rts_* and RX_DURING_TX are not supported.
+	 *
+	 * RTS_{ON,AFTER}_SEND are supported, but ignored; the transceiver
+	 * is connected in only one way and we don't need userspace to tell
+	 * us, but want to retain compatibility with applications that do.
+	 */
+};
+
+static void ni16550_rs485_setup(struct uart_port *port)
+{
+	port->rs485_config = ni16550_rs485_config;
+	port->rs485_supported = ni16550_rs485_supported;
+	/*
+	 * The hardware comes up by default in 2-wire auto mode and we
+	 * set the flags to represent that
+	 */
+	port->rs485.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND;
+}
+
+static int ni16550_port_startup(struct uart_port *port)
+{
+	int ret;
+
+	ret = serial8250_do_startup(port);
+	if (ret)
+		return ret;
+
+	return ni16550_enable_transceivers(port);
+}
+
+static void ni16550_port_shutdown(struct uart_port *port)
+{
+	ni16550_disable_transceivers(port);
+
+	serial8250_do_shutdown(port);
+}
+
+static int ni16550_get_regs(struct platform_device *pdev,
+			    struct uart_port *port)
+{
+	struct resource *regs;
+
+	regs = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (regs) {
+		port->iotype = UPIO_PORT;
+		port->iobase = regs->start;
+
+		return 0;
+	}
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (regs) {
+		port->iotype = UPIO_MEM;
+		port->mapbase = regs->start;
+		port->mapsize = resource_size(regs);
+		port->flags |= UPF_IOREMAP;
+
+		port->membase = devm_ioremap(&pdev->dev, port->mapbase,
+					     port->mapsize);
+		if (!port->membase)
+			return -ENOMEM;
+
+		return 0;
+	}
+
+	dev_err(&pdev->dev, "no registers defined\n");
+	return -EINVAL;
+}
+
+/*
+ * Very old implementations don't have the TFS or RFS registers
+ * defined, so we may read all-0s or all-1s. For such devices,
+ * assume a FIFO size of 128.
+ */
+static u8 ni16550_read_fifo_size(struct uart_8250_port *uart, int reg)
+{
+	u8 value = serial_in(uart, reg);
+
+	if (value == 0x00 || value == 0xFF)
+		return 128;
+
+	return value;
+}
+
+static void ni16550_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	up->mcr |= UART_MCR_CLKSEL;
+	serial8250_do_set_mctrl(port, mctrl);
+}
+
+static int ni16550_probe(struct platform_device *pdev)
+{
+	const struct ni16550_device_info *info;
+	struct device *dev = &pdev->dev;
+	struct uart_8250_port uart = {};
+	unsigned int txfifosz, rxfifosz;
+	unsigned int prescaler = 0;
+	struct ni16550_data *data;
+	const char *portmode;
+	bool rs232_property;
+	int ret;
+	int irq;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	spin_lock_init(&uart.port.lock);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = ni16550_get_regs(pdev, &uart.port);
+	if (ret < 0)
+		return ret;
+
+	/* early setup so that serial_in()/serial_out() work */
+	serial8250_set_defaults(&uart);
+
+	info = device_get_match_data(dev);
+
+	uart.port.dev		= dev;
+	uart.port.irq		= irq;
+	uart.port.irqflags	= IRQF_SHARED;
+	uart.port.flags		= UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF
+					| UPF_FIXED_PORT | UPF_FIXED_TYPE;
+	uart.port.startup	= ni16550_port_startup;
+	uart.port.shutdown	= ni16550_port_shutdown;
+
+	/*
+	 * Hardware instantiation of FIFO sizes are held in registers.
+	 */
+	txfifosz = ni16550_read_fifo_size(&uart, NI16550_TFS_OFFSET);
+	rxfifosz = ni16550_read_fifo_size(&uart, NI16550_RFS_OFFSET);
+
+	dev_dbg(dev, "NI 16550 has TX FIFO size %u, RX FIFO size %u\n",
+		txfifosz, rxfifosz);
+
+	uart.port.type		= PORT_16550A;
+	uart.port.fifosize	= txfifosz;
+	uart.tx_loadsz		= txfifosz;
+	uart.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10;
+	uart.capabilities	= UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR;
+
+	/*
+	 * Declaration of the base clock frequency can come from one of:
+	 * - static declaration in this driver (for older ACPI IDs)
+	 * - a "clock-frquency" ACPI
+	 */
+	if (info->uartclk)
+		uart.port.uartclk = info->uartclk;
+	if (device_property_read_u32(dev, "clock-frequency",
+				     &uart.port.uartclk)) {
+		data->clk = devm_clk_get_enabled(dev, NULL);
+		if (!IS_ERR(data->clk))
+			uart.port.uartclk = clk_get_rate(data->clk);
+	}
+
+	if (!uart.port.uartclk) {
+		dev_err(dev, "unable to determine clock frequency!\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	if (info->prescaler)
+		prescaler = info->prescaler;
+	device_property_read_u32(dev, "clock-prescaler", &prescaler);
+
+	if (prescaler != 0) {
+		uart.port.set_mctrl = ni16550_set_mctrl;
+		ni16550_config_prescaler(&uart, (u8)prescaler);
+	}
+
+	/*
+	 * The determination of whether or not this is an RS-485 or RS-232 port
+	 * can come from the PMR (if present), otherwise we're solely an RS-485
+	 * port.
+	 *
+	 * This is a device-specific property, and there are old devices in the
+	 * field using "transceiver" as an ACPI property, so we have to check
+	 * for that as well.
+	 */
+	if (!device_property_read_string(dev, "transceiver", &portmode)) {
+		rs232_property = strncmp(portmode, "RS-232", 6) == 0;
+
+		dev_dbg(dev, "port is in %s mode (via device property)\n",
+			rs232_property ? "RS-232" : "RS-485");
+	} else if (info->flags & NI_HAS_PMR) {
+		rs232_property = is_pmr_rs232_mode(&uart);
+
+		dev_dbg(dev, "port is in %s mode (via PMR)\n",
+			rs232_property ? "RS-232" : "RS-485");
+	} else {
+		rs232_property = 0;
+
+		dev_dbg(dev, "port is fixed as RS-485\n");
+	}
+
+	if (!rs232_property) {
+		/*
+		 * Neither the 'transceiver' property nor the PMR indicate
+		 * that this is an RS-232 port, so it must be an RS-485 one.
+		 */
+		ni16550_rs485_setup(&uart.port);
+	}
+
+	ret = serial8250_register_8250_port(&uart);
+	if (ret < 0)
+		goto err;
+	data->line = ret;
+
+	platform_set_drvdata(pdev, data);
+	return 0;
+
+err:
+	return ret;
+}
+
+static void ni16550_remove(struct platform_device *pdev)
+{
+	struct ni16550_data *data = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(data->line);
+}
+
+#ifdef CONFIG_ACPI
+/* NI 16550 RS-485 Interface */
+static const struct ni16550_device_info nic7750 = {
+	.uartclk = 33333333,
+};
+
+/* NI CVS-145x RS-485 Interface */
+static const struct ni16550_device_info nic7772 = {
+	.uartclk = 1843200,
+	.flags = NI_HAS_PMR,
+};
+
+/* NI cRIO-904x RS-485 Interface */
+static const struct ni16550_device_info nic792b = {
+	/* Sets UART clock rate to 22.222 MHz with 1.125 prescale */
+	.uartclk = 22222222,
+	.prescaler = 0x09,
+};
+
+/* NI sbRIO 96x8 RS-232/485 Interfaces */
+static const struct ni16550_device_info nic7a69 = {
+	/* Set UART clock rate to 29.629 MHz with 1.125 prescale */
+	.uartclk = 29629629,
+	.prescaler = 0x09,
+};
+static const struct acpi_device_id ni16550_acpi_match[] = {
+	{ "NIC7750",	(kernel_ulong_t)&nic7750 },
+	{ "NIC7772",	(kernel_ulong_t)&nic7772 },
+	{ "NIC792B",	(kernel_ulong_t)&nic792b },
+	{ "NIC7A69",	(kernel_ulong_t)&nic7a69 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, ni16550_acpi_match);
+#endif
+
+static struct platform_driver ni16550_driver = {
+	.driver = {
+		.name = "ni16550",
+		.acpi_match_table = ACPI_PTR(ni16550_acpi_match),
+	},
+	.probe = ni16550_probe,
+	.remove = ni16550_remove,
+};
+
+module_platform_driver(ni16550_driver);
+
+MODULE_AUTHOR("Emerson Electric Co.");
+MODULE_DESCRIPTION("NI 16550 Driver");
+MODULE_LICENSE("GPL");

drivers/tty/serial/8250/8250_omap.c

@@ -692,7 +692,7 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
 
 		/* Synchronize UART_IER access against the console. */
 		uart_port_lock(port);
-		up->ier = port->serial_in(port, UART_IER);
+		up->ier = serial_port_in(port, UART_IER);
 		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
 			port->ops->stop_rx(port);
 		} else {

drivers/tty/serial/8250/8250_pci.c

@@ -2727,6 +2727,22 @@ static struct pci_serial_quirk pci_serial_quirks[] = {
 		.init		= pci_oxsemi_tornado_init,
 		.setup		= pci_oxsemi_tornado_setup,
 	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4026,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
+	{
+		.vendor		= PCI_VENDOR_ID_INTASHIELD,
+		.device		= 0x4021,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.init		= pci_oxsemi_tornado_init,
+		.setup		= pci_oxsemi_tornado_setup,
+	},
 	{
 		.vendor         = PCI_VENDOR_ID_INTEL,
 		.device         = 0x8811,
@@ -5253,6 +5269,14 @@ static const struct pci_device_id serial_pci_tbl[] = {
 		PCI_ANY_ID, PCI_ANY_ID,
 		0, 0,
 		pbn_b2_2_115200 },
+	{       PCI_VENDOR_ID_INTASHIELD, 0x0BA2,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
+	{       PCI_VENDOR_ID_INTASHIELD, 0x0BA3,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_2_115200 },
 	/*
 	 * Brainboxes UC-235/246
 	 */
@@ -5373,6 +5397,14 @@ static const struct pci_device_id serial_pci_tbl[] = {
 		PCI_ANY_ID, PCI_ANY_ID,
 		0, 0,
 		pbn_b2_4_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C42,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_4_115200 },
+	{	PCI_VENDOR_ID_INTASHIELD, 0x0C43,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_b2_4_115200 },
 	/*
 	 * Brainboxes UC-420
 	 */
@@ -5599,6 +5631,20 @@ static const struct pci_device_id serial_pci_tbl[] = {
 		PCI_ANY_ID, PCI_ANY_ID,
 		0, 0,
 		pbn_oxsemi_1_15625000 },
+	/*
+	 * Brainboxes XC-235
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4026,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_1_15625000 },
+	/*
+	 * Brainboxes XC-475
+	 */
+	{	PCI_VENDOR_ID_INTASHIELD, 0x4021,
+		PCI_ANY_ID, PCI_ANY_ID,
+		0, 0,
+		pbn_oxsemi_1_15625000 },
 
 	/*
 	 * Perle PCI-RAS cards

drivers/tty/serial/8250/8250_port.c

@@ -1678,7 +1678,7 @@ static void serial8250_disable_ms(struct uart_port *port)
 	if (up->bugs & UART_BUG_NOMSR)
 		return;
 
-	mctrl_gpio_disable_ms(up->gpios);
+	mctrl_gpio_disable_ms_no_sync(up->gpios);
 
 	up->ier &= ~UART_IER_MSI;
 	serial_port_out(port, UART_IER, up->ier);
@@ -2406,28 +2406,26 @@ int serial8250_do_startup(struct uart_port *port)
 	 * test if we receive TX irq.  This way, we'll never enable
 	 * UART_BUG_TXEN.
 	 */
-	if (up->port.quirks & UPQ_NO_TXEN_TEST)
+	if (!(up->port.quirks & UPQ_NO_TXEN_TEST)) {
-		goto dont_test_tx_en;
+		/*
+		 * Do a quick test to see if we receive an interrupt when we
+		 * enable the TX irq.
+		 */
+		serial_port_out(port, UART_IER, UART_IER_THRI);
+		lsr = serial_port_in(port, UART_LSR);
+		iir = serial_port_in(port, UART_IIR);
+		serial_port_out(port, UART_IER, 0);
 
-	/*
+		if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
-	 * Do a quick test to see if we receive an interrupt when we enable
+			if (!(up->bugs & UART_BUG_TXEN)) {
-	 * the TX irq.
+				up->bugs |= UART_BUG_TXEN;
-	 */
+				dev_dbg(port->dev, "enabling bad tx status workarounds\n");
-	serial_port_out(port, UART_IER, UART_IER_THRI);
+			}
-	lsr = serial_port_in(port, UART_LSR);
+		} else {
-	iir = serial_port_in(port, UART_IIR);
+			up->bugs &= ~UART_BUG_TXEN;
-	serial_port_out(port, UART_IER, 0);
-
-	if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
-		if (!(up->bugs & UART_BUG_TXEN)) {
-			up->bugs |= UART_BUG_TXEN;
-			dev_dbg(port->dev, "enabling bad tx status workarounds\n");
 		}
-	} else {
-		up->bugs &= ~UART_BUG_TXEN;
 	}
 
-dont_test_tx_en:
 	uart_port_unlock_irqrestore(port, flags);
 
 	/*
@@ -2968,7 +2966,6 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
 {
 	unsigned int size = serial8250_port_size(up);
 	struct uart_port *port = &up->port;
-	int ret = 0;
 
 	switch (port->iotype) {
 	case UPIO_AU:
@@ -2977,32 +2974,28 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
 	case UPIO_MEM32BE:
 	case UPIO_MEM16:
 	case UPIO_MEM:
-		if (!port->mapbase) {
+		if (!port->mapbase)
-			ret = -EINVAL;
+			return -EINVAL;
-			break;
-		}
 
-		if (!request_mem_region(port->mapbase, size, "serial")) {
+		if (!request_mem_region(port->mapbase, size, "serial"))
-			ret = -EBUSY;
+			return -EBUSY;
-			break;
-		}
 
 		if (port->flags & UPF_IOREMAP) {
 			port->membase = ioremap(port->mapbase, size);
 			if (!port->membase) {
 				release_mem_region(port->mapbase, size);
-				ret = -ENOMEM;
+				return -ENOMEM;
 			}
 		}
-		break;
+		return 0;
-
 	case UPIO_HUB6:
 	case UPIO_PORT:
 		if (!request_region(port->iobase, size, "serial"))
-			ret = -EBUSY;
+			return -EBUSY;
-		break;
+		return 0;
 	}
-	return ret;
+
+	return 0;
 }
 
 static void serial8250_release_std_resource(struct uart_8250_port *up)

drivers/tty/serial/8250/8250_rsa.c

@@ -16,30 +16,27 @@ static unsigned int probe_rsa_count;
 
 static int rsa8250_request_resource(struct uart_8250_port *up)
 {
-	unsigned long start = UART_RSA_BASE << up->port.regshift;
-	unsigned int size = 8 << up->port.regshift;
 	struct uart_port *port = &up->port;
-	int ret = -EINVAL;
+	unsigned long start = UART_RSA_BASE << port->regshift;
+	unsigned int size = 8 << port->regshift;
 
 	switch (port->iotype) {
 	case UPIO_HUB6:
 	case UPIO_PORT:
 		start += port->iobase;
-		if (request_region(start, size, "serial-rsa"))
+		if (!request_region(start, size, "serial-rsa"))
-			ret = 0;
+			return -EBUSY;
-		else
+		return 0;
-			ret = -EBUSY;
+	default:
-		break;
+		return -EINVAL;
 	}
-
-	return ret;
 }
 
 static void rsa8250_release_resource(struct uart_8250_port *up)
 {
-	unsigned long offset = UART_RSA_BASE << up->port.regshift;
-	unsigned int size = 8 << up->port.regshift;
 	struct uart_port *port = &up->port;
+	unsigned long offset = UART_RSA_BASE << port->regshift;
+	unsigned int size = 8 << port->regshift;
 
 	switch (port->iotype) {
 	case UPIO_HUB6:

drivers/tty/serial/8250/Kconfig

@@ -569,6 +569,19 @@ config SERIAL_8250_BCM7271
 	  including DMA support and high accuracy BAUD rates, say
 	  Y to this option. If unsure, say N.
 
+config SERIAL_8250_NI
+	tristate "NI 16550 based serial port"
+	depends on SERIAL_8250
+	depends on (X86 && ACPI) || COMPILE_TEST
+	help
+	  This driver supports the integrated serial ports on National
+	  Instruments (NI) controller hardware. This is required for all NI
+	  controller models with onboard RS-485 or dual-mode RS-485/RS-232
+	  ports.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called 8250_ni.
+
 config SERIAL_OF_PLATFORM
 	tristate "Devicetree based probing for 8250 ports"
 	depends on SERIAL_8250 && OF

drivers/tty/serial/8250/Makefile

@@ -40,6 +40,7 @@ obj-$(CONFIG_SERIAL_8250_LPSS)		+= 8250_lpss.o
 obj-$(CONFIG_SERIAL_8250_MEN_MCB)	+= 8250_men_mcb.o
 obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
 obj-$(CONFIG_SERIAL_8250_MT6577)	+= 8250_mtk.o
+obj-$(CONFIG_SERIAL_8250_NI)		+= 8250_ni.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o
 obj-$(CONFIG_SERIAL_8250_OMAP)		+= 8250_omap.o
 obj-$(CONFIG_SERIAL_8250_PARISC)	+= 8250_parisc.o

drivers/tty/serial/Kconfig

@@ -179,25 +179,6 @@ config SERIAL_ATMEL_TTYAT
 
 	  Say Y if you have an external 8250/16C550 UART.  If unsure, say N.
 
-config SERIAL_KGDB_NMI
-	bool "Serial console over KGDB NMI debugger port"
-	depends on KGDB_SERIAL_CONSOLE
-	help
-	  This special driver allows you to temporary use NMI debugger port
-	  as a normal console (assuming that the port is attached to KGDB).
-
-	  Unlike KDB's disable_nmi command, with this driver you are always
-	  able to go back to the debugger using KGDB escape sequence ($3#33).
-	  This is because this console driver processes the input in NMI
-	  context, and thus is able to intercept the magic sequence.
-
-	  Note that since the console interprets input and uses polling
-	  communication methods, for things like PPP you still must fully
-	  detach debugger port from the KGDB NMI (i.e. disable_nmi), and
-	  use raw console.
-
-	  If unsure, say N.
-
 config SERIAL_MESON
 	tristate "Meson serial port support"
 	depends on ARCH_MESON || COMPILE_TEST
@@ -306,6 +287,29 @@ config SERIAL_TEGRA_TCU_CONSOLE
 
 	  If unsure, say Y.
 
+config SERIAL_TEGRA_UTC
+	tristate "NVIDIA Tegra UART Trace Controller"
+	depends on ARCH_TEGRA || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  Support for Tegra UTC (UART Trace controller) client serial port.
+
+	  UTC is a HW based serial port that allows multiplexing multiple data
+	  streams of up to 16 UTC clients into a single hardware serial port.
+
+config SERIAL_TEGRA_UTC_CONSOLE
+	bool "Support for console on a Tegra UTC serial port"
+	depends on SERIAL_TEGRA_UTC
+	select SERIAL_CORE_CONSOLE
+	default SERIAL_TEGRA_UTC
+	help
+	  If you say Y here, it will be possible to use a Tegra UTC client as
+	  the system console (the system console is the device which receives
+	  all kernel messages and warnings and which allows logins in single
+	  user mode).
+
+	  If unsure, say Y.
+
 config SERIAL_MAX3100
 	tristate "MAX3100/3110/3111/3222 support"
 	depends on SPI

drivers/tty/serial/Makefile

@@ -86,6 +86,7 @@ obj-$(CONFIG_SERIAL_STM32)		+= stm32-usart.o
 obj-$(CONFIG_SERIAL_SUNPLUS)		+= sunplus-uart.o
 obj-$(CONFIG_SERIAL_TEGRA)		+= serial-tegra.o
 obj-$(CONFIG_SERIAL_TEGRA_TCU)		+= tegra-tcu.o
+obj-$(CONFIG_SERIAL_TEGRA_UTC)		+= tegra-utc.o
 obj-$(CONFIG_SERIAL_TIMBERDALE)		+= timbuart.o
 obj-$(CONFIG_SERIAL_TXX9)		+= serial_txx9.o
 obj-$(CONFIG_SERIAL_UARTLITE)		+= uartlite.o
@@ -96,6 +97,5 @@ obj-$(CONFIG_SERIAL_ZS)			+= zs.o
 # GPIOLIB helpers for modem control lines
 obj-$(CONFIG_SERIAL_MCTRL_GPIO)	+= serial_mctrl_gpio.o
 
-obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
 obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_NUVOTON_MA35D1) += ma35d1_serial.o

drivers/tty/serial/amba-pl011.c

@@ -272,6 +272,7 @@ struct uart_amba_port {
 	enum pl011_rs485_tx_state	rs485_tx_state;
 	struct hrtimer		trigger_start_tx;
 	struct hrtimer		trigger_stop_tx;
+	bool			console_line_ended;
 #ifdef CONFIG_DMA_ENGINE
 	/* DMA stuff */
 	unsigned int		dmacr;		/* dma control reg */
@@ -2366,50 +2367,7 @@ static void pl011_console_putchar(struct uart_port *port, unsigned char ch)
 	while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
 		cpu_relax();
 	pl011_write(ch, uap, REG_DR);
-}
+	uap->console_line_ended = (ch == '\n');
-
-static void
-pl011_console_write(struct console *co, const char *s, unsigned int count)
-{
-	struct uart_amba_port *uap = amba_ports[co->index];
-	unsigned int old_cr = 0, new_cr;
-	unsigned long flags;
-	int locked = 1;
-
-	clk_enable(uap->clk);
-
-	if (oops_in_progress)
-		locked = uart_port_trylock_irqsave(&uap->port, &flags);
-	else
-		uart_port_lock_irqsave(&uap->port, &flags);
-
-	/*
-	 *	First save the CR then disable the interrupts
-	 */
-	if (!uap->vendor->always_enabled) {
-		old_cr = pl011_read(uap, REG_CR);
-		new_cr = old_cr & ~UART011_CR_CTSEN;
-		new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
-		pl011_write(new_cr, uap, REG_CR);
-	}
-
-	uart_console_write(&uap->port, s, count, pl011_console_putchar);
-
-	/*
-	 *	Finally, wait for transmitter to become empty and restore the
-	 *	TCR. Allow feature register bits to be inverted to work around
-	 *	errata.
-	 */
-	while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr)
-						& uap->vendor->fr_busy)
-		cpu_relax();
-	if (!uap->vendor->always_enabled)
-		pl011_write(old_cr, uap, REG_CR);
-
-	if (locked)
-		uart_port_unlock_irqrestore(&uap->port, flags);
-
-	clk_disable(uap->clk);
 }
 
 static void pl011_console_get_options(struct uart_amba_port *uap, int *baud,
@@ -2472,6 +2430,8 @@ static int pl011_console_setup(struct console *co, char *options)
 	if (ret)
 		return ret;
 
+	uap->console_line_ended = true;
+
 	if (dev_get_platdata(uap->port.dev)) {
 		struct amba_pl011_data *plat;
 
@@ -2555,14 +2515,105 @@ static int pl011_console_match(struct console *co, char *name, int idx,
 	return -ENODEV;
 }
 
+static void
+pl011_console_write_atomic(struct console *co, struct nbcon_write_context *wctxt)
+{
+	struct uart_amba_port *uap = amba_ports[co->index];
+	unsigned int old_cr = 0;
+
+	if (!nbcon_enter_unsafe(wctxt))
+		return;
+
+	clk_enable(uap->clk);
+
+	if (!uap->vendor->always_enabled) {
+		old_cr = pl011_read(uap, REG_CR);
+		pl011_write((old_cr & ~UART011_CR_CTSEN) | (UART01x_CR_UARTEN | UART011_CR_TXE),
+				uap, REG_CR);
+	}
+
+	if (!uap->console_line_ended)
+		uart_console_write(&uap->port, "\n", 1, pl011_console_putchar);
+	uart_console_write(&uap->port, wctxt->outbuf, wctxt->len, pl011_console_putchar);
+
+	while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr) & uap->vendor->fr_busy)
+		cpu_relax();
+
+	if (!uap->vendor->always_enabled)
+		pl011_write(old_cr, uap, REG_CR);
+
+	clk_disable(uap->clk);
+
+	nbcon_exit_unsafe(wctxt);
+}
+
+static void
+pl011_console_write_thread(struct console *co, struct nbcon_write_context *wctxt)
+{
+	struct uart_amba_port *uap = amba_ports[co->index];
+	unsigned int old_cr = 0;
+
+	if (!nbcon_enter_unsafe(wctxt))
+		return;
+
+	clk_enable(uap->clk);
+
+	if (!uap->vendor->always_enabled) {
+		old_cr = pl011_read(uap, REG_CR);
+		pl011_write((old_cr & ~UART011_CR_CTSEN) | (UART01x_CR_UARTEN | UART011_CR_TXE),
+				uap, REG_CR);
+	}
+
+	if (nbcon_exit_unsafe(wctxt)) {
+		int i;
+		unsigned int len = READ_ONCE(wctxt->len);
+
+		for (i = 0; i < len; i++) {
+			if (!nbcon_enter_unsafe(wctxt))
+				break;
+			uart_console_write(&uap->port, wctxt->outbuf + i, 1, pl011_console_putchar);
+			if (!nbcon_exit_unsafe(wctxt))
+				break;
+		}
+	}
+
+	while (!nbcon_enter_unsafe(wctxt))
+		nbcon_reacquire_nobuf(wctxt);
+
+	while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr) & uap->vendor->fr_busy)
+		cpu_relax();
+
+	if (!uap->vendor->always_enabled)
+		pl011_write(old_cr, uap, REG_CR);
+
+	clk_disable(uap->clk);
+
+	nbcon_exit_unsafe(wctxt);
+}
+
+static void
+pl011_console_device_lock(struct console *co, unsigned long *flags)
+{
+	__uart_port_lock_irqsave(&amba_ports[co->index]->port, flags);
+}
+
+static void
+pl011_console_device_unlock(struct console *co, unsigned long flags)
+{
+	__uart_port_unlock_irqrestore(&amba_ports[co->index]->port, flags);
+}
+
 static struct uart_driver amba_reg;
 static struct console amba_console = {
 	.name		= "ttyAMA",
-	.write		= pl011_console_write,
 	.device		= uart_console_device,
 	.setup		= pl011_console_setup,
 	.match		= pl011_console_match,
-	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
+	.write_atomic	= pl011_console_write_atomic,
+	.write_thread	= pl011_console_write_thread,
+	.device_lock	= pl011_console_device_lock,
+	.device_unlock	= pl011_console_device_unlock,
+	.flags		= CON_PRINTBUFFER | CON_ANYTIME | CON_NBCON,
 	.index		= -1,
 	.data		= &amba_reg,
 };
@@ -3000,7 +3051,7 @@ static const struct of_device_id sbsa_uart_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, sbsa_uart_of_match);
 
-static const struct acpi_device_id __maybe_unused sbsa_uart_acpi_match[] = {
+static const struct acpi_device_id sbsa_uart_acpi_match[] = {
 	{ "ARMH0011", 0 },
 	{ "ARMHB000", 0 },
 	{},
@@ -3013,8 +3064,8 @@ static struct platform_driver arm_sbsa_uart_platform_driver = {
 	.driver	= {
 		.name	= "sbsa-uart",
 		.pm	= &pl011_dev_pm_ops,
-		.of_match_table = of_match_ptr(sbsa_uart_of_match),
+		.of_match_table = sbsa_uart_of_match,
-		.acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match),
+		.acpi_match_table = sbsa_uart_acpi_match,
 		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
 	},
 };

drivers/tty/serial/atmel_serial.c

@@ -700,7 +700,7 @@ static void atmel_disable_ms(struct uart_port *port)
 
 	atmel_port->ms_irq_enabled = false;
 
-	mctrl_gpio_disable_ms(atmel_port->gpios);
+	mctrl_gpio_disable_ms_no_sync(atmel_port->gpios);
 
 	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS))
 		idr |= ATMEL_US_CTSIC;

drivers/tty/serial/icom.c

@@ -1764,11 +1764,10 @@ static int icom_probe(struct pci_dev *dev,
 		goto probe_exit1;
 	}
 
-	 /* save off irq and request irq line */
+	/* save off irq and request irq line */
-	 retval = request_irq(dev->irq, icom_interrupt, IRQF_SHARED, ICOM_DRIVER_NAME, (void *)icom_adapter);
+	retval = request_irq(dev->irq, icom_interrupt, IRQF_SHARED, ICOM_DRIVER_NAME, icom_adapter);
-	 if (retval) {
+	if (retval)
-		  goto probe_exit2;
+		goto probe_exit2;
-	 }
 
 	retval = icom_load_ports(icom_adapter);
 

drivers/tty/serial/imx.c

@@ -1608,7 +1608,7 @@ static void imx_uart_shutdown(struct uart_port *port)
 		imx_uart_dma_exit(sport);
 	}
 
-	mctrl_gpio_disable_ms(sport->gpios);
+	mctrl_gpio_disable_ms_sync(sport->gpios);
 
 	uart_port_lock_irqsave(&sport->port, &flags);
 	ucr2 = imx_uart_readl(sport, UCR2);

drivers/tty/serial/kgdb_nmi.c

@@ -1,280 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * KGDB NMI serial console
- *
- * Copyright 2010 Google, Inc.
- *		  Arve Hjønnevåg <arve@android.com>
- *		  Colin Cross <ccross@android.com>
- * Copyright 2012 Linaro Ltd.
- *		  Anton Vorontsov <anton.vorontsov@linaro.org>
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/compiler.h>
-#include <linux/slab.h>
-#include <linux/errno.h>
-#include <linux/atomic.h>
-#include <linux/console.h>
-#include <linux/tty.h>
-#include <linux/tty_driver.h>
-#include <linux/tty_flip.h>
-#include <linux/serial_core.h>
-#include <linux/interrupt.h>
-#include <linux/hrtimer.h>
-#include <linux/tick.h>
-#include <linux/kfifo.h>
-#include <linux/kgdb.h>
-#include <linux/kdb.h>
-
-static atomic_t kgdb_nmi_num_readers = ATOMIC_INIT(0);
-
-static int kgdb_nmi_console_setup(struct console *co, char *options)
-{
-	arch_kgdb_ops.enable_nmi(1);
-
-	/* The NMI console uses the dbg_io_ops to issue console messages. To
-	 * avoid duplicate messages during kdb sessions we must inform kdb's
-	 * I/O utilities that messages sent to the console will automatically
-	 * be displayed on the dbg_io.
-	 */
-	dbg_io_ops->cons = co;
-
-	return 0;
-}
-
-static void kgdb_nmi_console_write(struct console *co, const char *s, uint c)
-{
-	int i;
-
-	for (i = 0; i < c; i++)
-		dbg_io_ops->write_char(s[i]);
-}
-
-static struct tty_driver *kgdb_nmi_tty_driver;
-
-static struct tty_driver *kgdb_nmi_console_device(struct console *co, int *idx)
-{
-	*idx = co->index;
-	return kgdb_nmi_tty_driver;
-}
-
-static struct console kgdb_nmi_console = {
-	.name	= "ttyNMI",
-	.setup  = kgdb_nmi_console_setup,
-	.write	= kgdb_nmi_console_write,
-	.device	= kgdb_nmi_console_device,
-	.flags	= CON_PRINTBUFFER | CON_ANYTIME,
-	.index	= -1,
-};
-
-/*
- * This is usually the maximum rate on debug ports. We make fifo large enough
- * to make copy-pasting to the terminal usable.
- */
-#define KGDB_NMI_BAUD		115200
-#define KGDB_NMI_FIFO_SIZE	roundup_pow_of_two(KGDB_NMI_BAUD / 8 / HZ)
-
-struct kgdb_nmi_tty_priv {
-	struct tty_port port;
-	struct timer_list timer;
-	STRUCT_KFIFO(char, KGDB_NMI_FIFO_SIZE) fifo;
-};
-
-static struct tty_port *kgdb_nmi_port;
-
-/*
- * The tasklet is cheap, it does not cause wakeups when reschedules itself,
- * instead it waits for the next tick.
- */
-static void kgdb_nmi_tty_receiver(struct timer_list *t)
-{
-	struct kgdb_nmi_tty_priv *priv = from_timer(priv, t, timer);
-	char ch;
-
-	priv->timer.expires = jiffies + (HZ/100);
-	add_timer(&priv->timer);
-
-	if (likely(!atomic_read(&kgdb_nmi_num_readers) ||
-		   !kfifo_len(&priv->fifo)))
-		return;
-
-	while (kfifo_out(&priv->fifo, &ch, 1))
-		tty_insert_flip_char(&priv->port, ch, TTY_NORMAL);
-	tty_flip_buffer_push(&priv->port);
-}
-
-static int kgdb_nmi_tty_activate(struct tty_port *port, struct tty_struct *tty)
-{
-	struct kgdb_nmi_tty_priv *priv =
-	    container_of(port, struct kgdb_nmi_tty_priv, port);
-
-	kgdb_nmi_port = port;
-	priv->timer.expires = jiffies + (HZ/100);
-	add_timer(&priv->timer);
-
-	return 0;
-}
-
-static void kgdb_nmi_tty_shutdown(struct tty_port *port)
-{
-	struct kgdb_nmi_tty_priv *priv =
-	    container_of(port, struct kgdb_nmi_tty_priv, port);
-
-	del_timer(&priv->timer);
-	kgdb_nmi_port = NULL;
-}
-
-static const struct tty_port_operations kgdb_nmi_tty_port_ops = {
-	.activate	= kgdb_nmi_tty_activate,
-	.shutdown	= kgdb_nmi_tty_shutdown,
-};
-
-static int kgdb_nmi_tty_install(struct tty_driver *drv, struct tty_struct *tty)
-{
-	struct kgdb_nmi_tty_priv *priv;
-	int ret;
-
-	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
-
-	INIT_KFIFO(priv->fifo);
-	timer_setup(&priv->timer, kgdb_nmi_tty_receiver, 0);
-	tty_port_init(&priv->port);
-	priv->port.ops = &kgdb_nmi_tty_port_ops;
-	tty->driver_data = priv;
-
-	ret = tty_port_install(&priv->port, drv, tty);
-	if (ret) {
-		pr_err("%s: can't install tty port: %d\n", __func__, ret);
-		goto err;
-	}
-	return 0;
-err:
-	tty_port_destroy(&priv->port);
-	kfree(priv);
-	return ret;
-}
-
-static void kgdb_nmi_tty_cleanup(struct tty_struct *tty)
-{
-	struct kgdb_nmi_tty_priv *priv = tty->driver_data;
-
-	tty->driver_data = NULL;
-	tty_port_destroy(&priv->port);
-	kfree(priv);
-}
-
-static int kgdb_nmi_tty_open(struct tty_struct *tty, struct file *file)
-{
-	struct kgdb_nmi_tty_priv *priv = tty->driver_data;
-	unsigned int mode = file->f_flags & O_ACCMODE;
-	int ret;
-
-	ret = tty_port_open(&priv->port, tty, file);
-	if (!ret && (mode == O_RDONLY || mode == O_RDWR))
-		atomic_inc(&kgdb_nmi_num_readers);
-
-	return ret;
-}
-
-static void kgdb_nmi_tty_close(struct tty_struct *tty, struct file *file)
-{
-	struct kgdb_nmi_tty_priv *priv = tty->driver_data;
-	unsigned int mode = file->f_flags & O_ACCMODE;
-
-	if (mode == O_RDONLY || mode == O_RDWR)
-		atomic_dec(&kgdb_nmi_num_readers);
-
-	tty_port_close(&priv->port, tty, file);
-}
-
-static void kgdb_nmi_tty_hangup(struct tty_struct *tty)
-{
-	struct kgdb_nmi_tty_priv *priv = tty->driver_data;
-
-	tty_port_hangup(&priv->port);
-}
-
-static unsigned int kgdb_nmi_tty_write_room(struct tty_struct *tty)
-{
-	/* Actually, we can handle any amount as we use polled writes. */
-	return 2048;
-}
-
-static ssize_t kgdb_nmi_tty_write(struct tty_struct *tty, const u8 *buf,
-				  size_t c)
-{
-	int i;
-
-	for (i = 0; i < c; i++)
-		dbg_io_ops->write_char(buf[i]);
-	return c;
-}
-
-static const struct tty_operations kgdb_nmi_tty_ops = {
-	.open		= kgdb_nmi_tty_open,
-	.close		= kgdb_nmi_tty_close,
-	.install	= kgdb_nmi_tty_install,
-	.cleanup	= kgdb_nmi_tty_cleanup,
-	.hangup		= kgdb_nmi_tty_hangup,
-	.write_room	= kgdb_nmi_tty_write_room,
-	.write		= kgdb_nmi_tty_write,
-};
-
-int kgdb_register_nmi_console(void)
-{
-	int ret;
-
-	if (!arch_kgdb_ops.enable_nmi)
-		return 0;
-
-	kgdb_nmi_tty_driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
-	if (IS_ERR(kgdb_nmi_tty_driver)) {
-		pr_err("%s: cannot allocate tty\n", __func__);
-		return PTR_ERR(kgdb_nmi_tty_driver);
-	}
-	kgdb_nmi_tty_driver->driver_name	= "ttyNMI";
-	kgdb_nmi_tty_driver->name		= "ttyNMI";
-	kgdb_nmi_tty_driver->num		= 1;
-	kgdb_nmi_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
-	kgdb_nmi_tty_driver->subtype		= SERIAL_TYPE_NORMAL;
-	kgdb_nmi_tty_driver->init_termios	= tty_std_termios;
-	tty_termios_encode_baud_rate(&kgdb_nmi_tty_driver->init_termios,
-				     KGDB_NMI_BAUD, KGDB_NMI_BAUD);
-	tty_set_operations(kgdb_nmi_tty_driver, &kgdb_nmi_tty_ops);
-
-	ret = tty_register_driver(kgdb_nmi_tty_driver);
-	if (ret) {
-		pr_err("%s: can't register tty driver: %d\n", __func__, ret);
-		goto err_drv_reg;
-	}
-
-	register_console(&kgdb_nmi_console);
-
-	return 0;
-err_drv_reg:
-	tty_driver_kref_put(kgdb_nmi_tty_driver);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(kgdb_register_nmi_console);
-
-int kgdb_unregister_nmi_console(void)
-{
-	int ret;
-
-	if (!arch_kgdb_ops.enable_nmi)
-		return 0;
-	arch_kgdb_ops.enable_nmi(0);
-
-	ret = unregister_console(&kgdb_nmi_console);
-	if (ret)
-		return ret;
-
-	tty_unregister_driver(kgdb_nmi_tty_driver);
-	tty_driver_kref_put(kgdb_nmi_tty_driver);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(kgdb_unregister_nmi_console);

drivers/tty/serial/kgdboc.c

@@ -186,8 +186,6 @@ static void cleanup_kgdboc(void)
 	if (configured != 1)
 		return;
 
-	if (kgdb_unregister_nmi_console())
-		return;
 	kgdboc_unregister_kbd();
 	kgdb_unregister_io_module(&kgdboc_io_ops);
 }
@@ -250,16 +248,10 @@ do_register:
 	if (err)
 		goto noconfig;
 
-	err = kgdb_register_nmi_console();
-	if (err)
-		goto nmi_con_failed;
-
 	configured = 1;
 
 	return 0;
 
-nmi_con_failed:
-	kgdb_unregister_io_module(&kgdboc_io_ops);
 noconfig:
 	kgdboc_unregister_kbd();
 	configured = 0;

drivers/tty/serial/ma35d1_serial.c

@@ -799,7 +799,7 @@ static struct platform_driver ma35d1serial_driver = {
 	.resume     = ma35d1serial_resume,
 	.driver     = {
 		.name   = "ma35d1-uart",
-		.of_match_table = of_match_ptr(ma35d1_serial_of_match),
+		.of_match_table = ma35d1_serial_of_match,
 	},
 };
 

drivers/tty/serial/mpc52xx_uart.c

@@ -1351,7 +1351,6 @@ static const struct uart_ops mpc52xx_uart_ops = {
 	.startup	= mpc52xx_uart_startup,
 	.shutdown	= mpc52xx_uart_shutdown,
 	.set_termios	= mpc52xx_uart_set_termios,
-/*	.pm		= mpc52xx_uart_pm,		Not supported yet */
 	.type		= mpc52xx_uart_type,
 	.release_port	= mpc52xx_uart_release_port,
 	.request_port	= mpc52xx_uart_request_port,

drivers/tty/serial/pch_uart.c

@@ -1515,7 +1515,6 @@ static const struct uart_ops pch_uart_ops = {
 	.startup = pch_uart_startup,
 	.shutdown = pch_uart_shutdown,
 	.set_termios = pch_uart_set_termios,
-/*	.pm		= pch_uart_pm,		Not supported yet */
 	.type = pch_uart_type,
 	.release_port = pch_uart_release_port,
 	.request_port = pch_uart_request_port,

drivers/tty/serial/serial_core.c

@@ -895,8 +895,8 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
 {
 	struct uart_port *uport = uart_port_check(state);
 	unsigned long new_port;
-	unsigned int change_irq, change_port, closing_wait;
+	unsigned int old_custom_divisor, close_delay, closing_wait;
-	unsigned int old_custom_divisor, close_delay;
+	bool change_irq, change_port;
 	upf_t old_flags, new_flags;
 	int retval;
 
@@ -2013,9 +2013,8 @@ static const char *uart_type(struct uart_port *port)
 
 #ifdef CONFIG_PROC_FS
 
-static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
+static void uart_line_info(struct seq_file *m, struct uart_state *state)
 {
-	struct uart_state *state = drv->state + i;
 	struct tty_port *port = &state->port;
 	enum uart_pm_state pm_state;
 	struct uart_port *uport;
@@ -2100,7 +2099,7 @@ static int uart_proc_show(struct seq_file *m, void *v)
 
 	seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
 	for (i = 0; i < drv->nr; i++)
-		uart_line_info(m, drv, i);
+		uart_line_info(m, drv->state + i);
 	return 0;
 }
 #endif
@@ -3156,7 +3155,6 @@ static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *u
 	if (uport->cons && uport->dev)
 		of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
 
-	tty_port_link_device(port, drv->tty_driver, uport->line);
 	uart_configure_port(drv, state, uport);
 
 	port->console = uart_console(uport);

drivers/tty/serial/serial_mctrl_gpio.c

@@ -217,7 +217,7 @@ static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
  *
  * This will get the {cts,rts,...}-gpios from device tree if they are present
  * and request them, set direction etc, and return an allocated structure.
- * `devm_*` functions are used, so there's no need to call mctrl_gpio_free().
+ * `devm_*` functions are used, so there's no need to explicitly free.
  * As this sets up the irq handling, make sure to not handle changes to the
  * gpio input lines in your driver, too.
  */
@@ -267,32 +267,6 @@ struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
 }
 EXPORT_SYMBOL_GPL(mctrl_gpio_init);
 
-/**
- * mctrl_gpio_free - explicitly free uart gpios
- * @dev: uart port's device
- * @gpios: gpios structure to be freed
- *
- * This will free the requested gpios in mctrl_gpio_init(). As `devm_*`
- * functions are used, there's generally no need to call this function.
- */
-void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
-{
-	enum mctrl_gpio_idx i;
-
-	if (gpios == NULL)
-		return;
-
-	for (i = 0; i < UART_GPIO_MAX; i++) {
-		if (gpios->irq[i])
-			devm_free_irq(gpios->port->dev, gpios->irq[i], gpios);
-
-		if (gpios->gpio[i])
-			devm_gpiod_put(dev, gpios->gpio[i]);
-	}
-	devm_kfree(dev, gpios);
-}
-EXPORT_SYMBOL_GPL(mctrl_gpio_free);
-
 /**
  * mctrl_gpio_enable_ms - enable irqs and handling of changes to the ms lines
  * @gpios: gpios to enable
@@ -322,11 +296,7 @@ void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
 }
 EXPORT_SYMBOL_GPL(mctrl_gpio_enable_ms);
 
-/**
+static void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios, bool sync)
- * mctrl_gpio_disable_ms - disable irqs and handling of changes to the ms lines
- * @gpios: gpios to disable
- */
-void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
 {
 	enum mctrl_gpio_idx i;
 
@@ -342,10 +312,34 @@ void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
 		if (!gpios->irq[i])
 			continue;
 
-		disable_irq(gpios->irq[i]);
+		if (sync)
+			disable_irq(gpios->irq[i]);
+		else
+			disable_irq_nosync(gpios->irq[i]);
 	}
 }
-EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms);
+
+/**
+ * mctrl_gpio_disable_ms_sync - disable irqs and handling of changes to the ms
+ * lines, and wait for any pending IRQ to be processed
+ * @gpios: gpios to disable
+ */
+void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios)
+{
+	mctrl_gpio_disable_ms(gpios, true);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms_sync);
+
+/**
+ * mctrl_gpio_disable_ms_no_sync - disable irqs and handling of changes to the
+ * ms lines, and return immediately
+ * @gpios: gpios to disable
+ */
+void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios)
+{
+	mctrl_gpio_disable_ms(gpios, false);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms_no_sync);
 
 void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios)
 {

drivers/tty/serial/serial_mctrl_gpio.h

@@ -59,7 +59,7 @@ struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
 /*
  * Request and set direction of modem control line GPIOs and set up irq
  * handling.
- * devm_* functions are used, so there's no need to call mctrl_gpio_free().
+ * devm_* functions are used, so there's no need to explicitly free.
  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
  * allocation error.
  */
@@ -67,29 +67,29 @@ struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx);
 
 /*
  * Request and set direction of modem control line GPIOs.
- * devm_* functions are used, so there's no need to call mctrl_gpio_free().
+ * devm_* functions are used, so there's no need to explicitly free.
  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
  * allocation error.
  */
 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev,
 					   unsigned int idx);
 
-/*
- * Free the mctrl_gpios structure.
- * Normally, this function will not be called, as the GPIOs will
- * be disposed of by the resource management code.
- */
-void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
-
 /*
  * Enable gpio interrupts to report status line changes.
  */
 void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
 
 /*
- * Disable gpio interrupts to report status line changes.
+ * Disable gpio interrupts to report status line changes, and block until
+ * any corresponding IRQ is processed
  */
-void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
+void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios);
+
+/*
+ * Disable gpio interrupts to report status line changes, and return
+ * immediately
+ */
+void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios);
 
 /*
  * Enable gpio wakeup interrupts to enable wake up source.
@@ -139,16 +139,15 @@ struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
 	return NULL;
 }
 
-static inline
-void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
-{
-}
-
 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
 {
 }
 
-static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
+static inline void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios)
+{
+}
+
+static inline void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios)
 {
 }
 

drivers/tty/serial/sh-sci.c

@@ -104,6 +104,20 @@ struct plat_sci_reg {
 	u8 offset, size;
 };
 
+struct sci_suspend_regs {
+	u16 scdl;
+	u16 sccks;
+	u16 scsmr;
+	u16 scscr;
+	u16 scfcr;
+	u16 scsptr;
+	u16 hssrr;
+	u16 scpcr;
+	u16 scpdr;
+	u8 scbrr;
+	u8 semr;
+};
+
 struct sci_port_params {
 	const struct plat_sci_reg regs[SCIx_NR_REGS];
 	unsigned int fifosize;
@@ -134,6 +148,8 @@ struct sci_port {
 	struct dma_chan			*chan_tx;
 	struct dma_chan			*chan_rx;
 
+	struct reset_control		*rstc;
+
 #ifdef CONFIG_SERIAL_SH_SCI_DMA
 	struct dma_chan			*chan_tx_saved;
 	struct dma_chan			*chan_rx_saved;
@@ -153,6 +169,7 @@ struct sci_port {
 	int				rx_trigger;
 	struct timer_list		rx_fifo_timer;
 	int				rx_fifo_timeout;
+	struct sci_suspend_regs		suspend_regs;
 	u16				hscif_tot;
 
 	bool has_rtscts;
@@ -2297,7 +2314,7 @@ static void sci_shutdown(struct uart_port *port)
 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
 
 	s->autorts = false;
-	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
+	mctrl_gpio_disable_ms_sync(to_sci_port(port)->gpios);
 
 	uart_port_lock_irqsave(port, &flags);
 	sci_stop_rx(port);
@@ -3373,6 +3390,7 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
 	}
 
 	sp = &sci_ports[id];
+	sp->rstc = rstc;
 	*dev_id = id;
 
 	p->type = SCI_OF_TYPE(data);
@@ -3545,13 +3563,77 @@ static int sci_probe(struct platform_device *dev)
 	return 0;
 }
 
+static void sci_console_save(struct sci_port *s)
+{
+	struct sci_suspend_regs *regs = &s->suspend_regs;
+	struct uart_port *port = &s->port;
+
+	if (sci_getreg(port, SCDL)->size)
+		regs->scdl = sci_serial_in(port, SCDL);
+	if (sci_getreg(port, SCCKS)->size)
+		regs->sccks = sci_serial_in(port, SCCKS);
+	if (sci_getreg(port, SCSMR)->size)
+		regs->scsmr = sci_serial_in(port, SCSMR);
+	if (sci_getreg(port, SCSCR)->size)
+		regs->scscr = sci_serial_in(port, SCSCR);
+	if (sci_getreg(port, SCFCR)->size)
+		regs->scfcr = sci_serial_in(port, SCFCR);
+	if (sci_getreg(port, SCSPTR)->size)
+		regs->scsptr = sci_serial_in(port, SCSPTR);
+	if (sci_getreg(port, SCBRR)->size)
+		regs->scbrr = sci_serial_in(port, SCBRR);
+	if (sci_getreg(port, HSSRR)->size)
+		regs->hssrr = sci_serial_in(port, HSSRR);
+	if (sci_getreg(port, SCPCR)->size)
+		regs->scpcr = sci_serial_in(port, SCPCR);
+	if (sci_getreg(port, SCPDR)->size)
+		regs->scpdr = sci_serial_in(port, SCPDR);
+	if (sci_getreg(port, SEMR)->size)
+		regs->semr = sci_serial_in(port, SEMR);
+}
+
+static void sci_console_restore(struct sci_port *s)
+{
+	struct sci_suspend_regs *regs = &s->suspend_regs;
+	struct uart_port *port = &s->port;
+
+	if (sci_getreg(port, SCDL)->size)
+		sci_serial_out(port, SCDL, regs->scdl);
+	if (sci_getreg(port, SCCKS)->size)
+		sci_serial_out(port, SCCKS, regs->sccks);
+	if (sci_getreg(port, SCSMR)->size)
+		sci_serial_out(port, SCSMR, regs->scsmr);
+	if (sci_getreg(port, SCSCR)->size)
+		sci_serial_out(port, SCSCR, regs->scscr);
+	if (sci_getreg(port, SCFCR)->size)
+		sci_serial_out(port, SCFCR, regs->scfcr);
+	if (sci_getreg(port, SCSPTR)->size)
+		sci_serial_out(port, SCSPTR, regs->scsptr);
+	if (sci_getreg(port, SCBRR)->size)
+		sci_serial_out(port, SCBRR, regs->scbrr);
+	if (sci_getreg(port, HSSRR)->size)
+		sci_serial_out(port, HSSRR, regs->hssrr);
+	if (sci_getreg(port, SCPCR)->size)
+		sci_serial_out(port, SCPCR, regs->scpcr);
+	if (sci_getreg(port, SCPDR)->size)
+		sci_serial_out(port, SCPDR, regs->scpdr);
+	if (sci_getreg(port, SEMR)->size)
+		sci_serial_out(port, SEMR, regs->semr);
+}
+
 static __maybe_unused int sci_suspend(struct device *dev)
 {
 	struct sci_port *sport = dev_get_drvdata(dev);
 
-	if (sport)
+	if (sport) {
 		uart_suspend_port(&sci_uart_driver, &sport->port);
 
+		if (!console_suspend_enabled && uart_console(&sport->port))
+			sci_console_save(sport);
+		else
+			return reset_control_assert(sport->rstc);
+	}
+
 	return 0;
 }
 
@@ -3559,8 +3641,18 @@ static __maybe_unused int sci_resume(struct device *dev)
 {
 	struct sci_port *sport = dev_get_drvdata(dev);
 
-	if (sport)
+	if (sport) {
+		if (!console_suspend_enabled && uart_console(&sport->port)) {
+			sci_console_restore(sport);
+		} else {
+			int ret = reset_control_deassert(sport->rstc);
+
+			if (ret)
+				return ret;
+		}
+
 		uart_resume_port(&sci_uart_driver, &sport->port);
+	}
 
 	return 0;
 }

drivers/tty/serial/stm32-usart.c

@@ -944,7 +944,7 @@ static void stm32_usart_enable_ms(struct uart_port *port)
 
 static void stm32_usart_disable_ms(struct uart_port *port)
 {
-	mctrl_gpio_disable_ms(to_stm32_port(port)->gpios);
+	mctrl_gpio_disable_ms_sync(to_stm32_port(port)->gpios);
 }
 
 /* Transmit stop */
@@ -965,10 +965,8 @@ static void stm32_usart_start_tx(struct uart_port *port)
 {
 	struct tty_port *tport = &port->state->port;
 
-	if (kfifo_is_empty(&tport->xmit_fifo) && !port->x_char) {
+	if (kfifo_is_empty(&tport->xmit_fifo) && !port->x_char)
-		stm32_usart_rs485_rts_disable(port);
 		return;
-	}
 
 	stm32_usart_rs485_rts_enable(port);
 

drivers/tty/serial/sunsu.c

@@ -150,16 +150,6 @@ static void serial_out(struct uart_sunsu_port *up, int offset, int value)
 	}
 }
 
-/*
- * We used to support using pause I/O for certain machines.  We
- * haven't supported this for a while, but just in case it's badly
- * needed for certain old 386 machines, I've left these #define's
- * in....
- */
-#define serial_inp(up, offset)		serial_in(up, offset)
-#define serial_outp(up, offset, value)	serial_out(up, offset, value)
-
-
 /*
  * For the 16C950
  */
@@ -169,20 +159,6 @@ static void serial_icr_write(struct uart_sunsu_port *up, int offset, int value)
 	serial_out(up, UART_ICR, value);
 }
 
-#if 0 /* Unused currently */
-static unsigned int serial_icr_read(struct uart_sunsu_port *up, int offset)
-{
-	unsigned int value;
-
-	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
-	serial_out(up, UART_SCR, offset);
-	value = serial_in(up, UART_ICR);
-	serial_icr_write(up, UART_ACR, up->acr);
-
-	return value;
-}
-#endif
-
 #ifdef CONFIG_SERIAL_8250_RSA
 /*
  * Attempts to turn on the RSA FIFO.  Returns zero on failure.
@@ -193,12 +169,12 @@ static int __enable_rsa(struct uart_sunsu_port *up)
 	unsigned char mode;
 	int result;
 
-	mode = serial_inp(up, UART_RSA_MSR);
+	mode = serial_in(up, UART_RSA_MSR);
 	result = mode & UART_RSA_MSR_FIFO;
 
 	if (!result) {
-		serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
+		serial_out(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
-		mode = serial_inp(up, UART_RSA_MSR);
+		mode = serial_in(up, UART_RSA_MSR);
 		result = mode & UART_RSA_MSR_FIFO;
 	}
 
@@ -217,7 +193,7 @@ static void enable_rsa(struct uart_sunsu_port *up)
 			uart_port_unlock_irq(&up->port);
 		}
 		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
-			serial_outp(up, UART_RSA_FRR, 0);
+			serial_out(up, UART_RSA_FRR, 0);
 	}
 }
 
@@ -236,12 +212,12 @@ static void disable_rsa(struct uart_sunsu_port *up)
 	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
 		uart_port_lock_irq(&up->port);
 
-		mode = serial_inp(up, UART_RSA_MSR);
+		mode = serial_in(up, UART_RSA_MSR);
 		result = !(mode & UART_RSA_MSR_FIFO);
 
 		if (!result) {
-			serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
+			serial_out(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
-			mode = serial_inp(up, UART_RSA_MSR);
+			mode = serial_in(up, UART_RSA_MSR);
 			result = !(mode & UART_RSA_MSR_FIFO);
 		}
 
@@ -326,7 +302,7 @@ receive_chars(struct uart_sunsu_port *up, unsigned char *status)
 	int saw_console_brk = 0;
 
 	do {
-		ch = serial_inp(up, UART_RX);
+		ch = serial_in(up, UART_RX);
 		flag = TTY_NORMAL;
 		up->port.icount.rx++;
 
@@ -387,7 +363,7 @@ receive_chars(struct uart_sunsu_port *up, unsigned char *status)
 			 */
 			 tty_insert_flip_char(port, 0, TTY_OVERRUN);
 	ignore_char:
-		*status = serial_inp(up, UART_LSR);
+		*status = serial_in(up, UART_LSR);
 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
 
 	if (saw_console_brk)
@@ -401,7 +377,7 @@ static void transmit_chars(struct uart_sunsu_port *up)
 	int count;
 
 	if (up->port.x_char) {
-		serial_outp(up, UART_TX, up->port.x_char);
+		serial_out(up, UART_TX, up->port.x_char);
 		up->port.icount.tx++;
 		up->port.x_char = 0;
 		return;
@@ -460,7 +436,7 @@ static irqreturn_t sunsu_serial_interrupt(int irq, void *dev_id)
 	uart_port_lock_irqsave(&up->port, &flags);
 
 	do {
-		status = serial_inp(up, UART_LSR);
+		status = serial_in(up, UART_LSR);
 		if (status & UART_LSR_DR)
 			receive_chars(up, &status);
 		check_modem_status(up);
@@ -498,7 +474,7 @@ static void sunsu_change_mouse_baud(struct uart_sunsu_port *up)
 static void receive_kbd_ms_chars(struct uart_sunsu_port *up, int is_break)
 {
 	do {
-		unsigned char ch = serial_inp(up, UART_RX);
+		unsigned char ch = serial_in(up, UART_RX);
 
 		/* Stop-A is handled by drivers/char/keyboard.c now. */
 		if (up->su_type == SU_PORT_KBD) {
@@ -530,7 +506,7 @@ static irqreturn_t sunsu_kbd_ms_interrupt(int irq, void *dev_id)
 	struct uart_sunsu_port *up = dev_id;
 
 	if (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT)) {
-		unsigned char status = serial_inp(up, UART_LSR);
+		unsigned char status = serial_in(up, UART_LSR);
 
 		if ((status & UART_LSR_DR) || (status & UART_LSR_BI))
 			receive_kbd_ms_chars(up, (status & UART_LSR_BI) != 0);
@@ -619,14 +595,14 @@ static int sunsu_startup(struct uart_port *port)
 	if (up->port.type == PORT_16C950) {
 		/* Wake up and initialize UART */
 		up->acr = 0;
-		serial_outp(up, UART_LCR, 0xBF);
+		serial_out(up, UART_LCR, 0xBF);
-		serial_outp(up, UART_EFR, UART_EFR_ECB);
+		serial_out(up, UART_EFR, UART_EFR_ECB);
-		serial_outp(up, UART_IER, 0);
+		serial_out(up, UART_IER, 0);
-		serial_outp(up, UART_LCR, 0);
+		serial_out(up, UART_LCR, 0);
 		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
-		serial_outp(up, UART_LCR, 0xBF);
+		serial_out(up, UART_LCR, 0xBF);
-		serial_outp(up, UART_EFR, UART_EFR_ECB);
+		serial_out(up, UART_EFR, UART_EFR_ECB);
-		serial_outp(up, UART_LCR, 0);
+		serial_out(up, UART_LCR, 0);
 	}
 
 #ifdef CONFIG_SERIAL_8250_RSA
@@ -642,19 +618,19 @@ static int sunsu_startup(struct uart_port *port)
 	 * (they will be reenabled in set_termios())
 	 */
 	if (uart_config[up->port.type].flags & UART_CLEAR_FIFO) {
-		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+		serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
-		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+		serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
 				UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
-		serial_outp(up, UART_FCR, 0);
+		serial_out(up, UART_FCR, 0);
 	}
 
 	/*
 	 * Clear the interrupt registers.
 	 */
-	(void) serial_inp(up, UART_LSR);
+	(void) serial_in(up, UART_LSR);
-	(void) serial_inp(up, UART_RX);
+	(void) serial_in(up, UART_RX);
-	(void) serial_inp(up, UART_IIR);
+	(void) serial_in(up, UART_IIR);
-	(void) serial_inp(up, UART_MSR);
+	(void) serial_in(up, UART_MSR);
 
 	/*
 	 * At this point, there's no way the LSR could still be 0xff;
@@ -662,7 +638,7 @@ static int sunsu_startup(struct uart_port *port)
 	 * here.
 	 */
 	if (!(up->port.flags & UPF_BUGGY_UART) &&
-	    (serial_inp(up, UART_LSR) == 0xff)) {
+	    (serial_in(up, UART_LSR) == 0xff)) {
 		printk("ttyS%d: LSR safety check engaged!\n", up->port.line);
 		return -ENODEV;
 	}
@@ -682,7 +658,7 @@ static int sunsu_startup(struct uart_port *port)
 	/*
 	 * Now, initialize the UART
 	 */
-	serial_outp(up, UART_LCR, UART_LCR_WLEN8);
+	serial_out(up, UART_LCR, UART_LCR_WLEN8);
 
 	uart_port_lock_irqsave(&up->port, &flags);
 
@@ -697,7 +673,7 @@ static int sunsu_startup(struct uart_port *port)
 	 * anyway, so we don't enable them here.
 	 */
 	up->ier = UART_IER_RLSI | UART_IER_RDI;
-	serial_outp(up, UART_IER, up->ier);
+	serial_out(up, UART_IER, up->ier);
 
 	if (up->port.flags & UPF_FOURPORT) {
 		unsigned int icp;
@@ -712,10 +688,10 @@ static int sunsu_startup(struct uart_port *port)
 	/*
 	 * And clear the interrupt registers again for luck.
 	 */
-	(void) serial_inp(up, UART_LSR);
+	(void) serial_in(up, UART_LSR);
-	(void) serial_inp(up, UART_RX);
+	(void) serial_in(up, UART_RX);
-	(void) serial_inp(up, UART_IIR);
+	(void) serial_in(up, UART_IIR);
-	(void) serial_inp(up, UART_MSR);
+	(void) serial_in(up, UART_MSR);
 
 	return 0;
 }
@@ -730,7 +706,7 @@ static void sunsu_shutdown(struct uart_port *port)
 	 * Disable interrupts from this port
 	 */
 	up->ier = 0;
-	serial_outp(up, UART_IER, 0);
+	serial_out(up, UART_IER, 0);
 
 	uart_port_lock_irqsave(&up->port, &flags);
 	if (up->port.flags & UPF_FOURPORT) {
@@ -746,11 +722,11 @@ static void sunsu_shutdown(struct uart_port *port)
 	/*
 	 * Disable break condition and FIFOs
 	 */
-	serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
+	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
-	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
 				  UART_FCR_CLEAR_RCVR |
 				  UART_FCR_CLEAR_XMIT);
-	serial_outp(up, UART_FCR, 0);
+	serial_out(up, UART_FCR, 0);
 
 #ifdef CONFIG_SERIAL_8250_RSA
 	/*
@@ -872,22 +848,22 @@ sunsu_change_speed(struct uart_port *port, unsigned int cflag,
 	serial_out(up, UART_IER, up->ier);
 
 	if (uart_config[up->port.type].flags & UART_STARTECH) {
-		serial_outp(up, UART_LCR, 0xBF);
+		serial_out(up, UART_LCR, 0xBF);
-		serial_outp(up, UART_EFR, cflag & CRTSCTS ? UART_EFR_CTS :0);
+		serial_out(up, UART_EFR, cflag & CRTSCTS ? UART_EFR_CTS :0);
 	}
-	serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
+	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
-	serial_outp(up, UART_DLL, quot & 0xff);		/* LS of divisor */
+	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
-	serial_outp(up, UART_DLM, quot >> 8);		/* MS of divisor */
+	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
 	if (up->port.type == PORT_16750)
-		serial_outp(up, UART_FCR, fcr);		/* set fcr */
+		serial_out(up, UART_FCR, fcr);		/* set fcr */
-	serial_outp(up, UART_LCR, cval);		/* reset DLAB */
+	serial_out(up, UART_LCR, cval);		/* reset DLAB */
 	up->lcr = cval;					/* Save LCR */
 	if (up->port.type != PORT_16750) {
 		if (fcr & UART_FCR_ENABLE_FIFO) {
 			/* emulated UARTs (Lucent Venus 167x) need two steps */
-			serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+			serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
 		}
-		serial_outp(up, UART_FCR, fcr);		/* set fcr */
+		serial_out(up, UART_FCR, fcr);		/* set fcr */
 	}
 
 	up->cflag = cflag;
@@ -1051,18 +1027,18 @@ static void sunsu_autoconfig(struct uart_sunsu_port *up)
 		 * 0x80 is a non-existent port; which should be safe since
 		 * include/asm/io.h also makes this assumption.
 		 */
-		scratch = serial_inp(up, UART_IER);
+		scratch = serial_in(up, UART_IER);
-		serial_outp(up, UART_IER, 0);
+		serial_out(up, UART_IER, 0);
 #ifdef __i386__
 		outb(0xff, 0x080);
 #endif
-		scratch2 = serial_inp(up, UART_IER);
+		scratch2 = serial_in(up, UART_IER);
-		serial_outp(up, UART_IER, 0x0f);
+		serial_out(up, UART_IER, 0x0f);
 #ifdef __i386__
 		outb(0, 0x080);
 #endif
-		scratch3 = serial_inp(up, UART_IER);
+		scratch3 = serial_in(up, UART_IER);
-		serial_outp(up, UART_IER, scratch);
+		serial_out(up, UART_IER, scratch);
 		if (scratch2 != 0 || scratch3 != 0x0F)
 			goto out;	/* We failed; there's nothing here */
 	}
@@ -1080,16 +1056,16 @@ static void sunsu_autoconfig(struct uart_sunsu_port *up)
 	 * that conflicts with COM 1-4 --- we hope!
 	 */
 	if (!(up->port.flags & UPF_SKIP_TEST)) {
-		serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
+		serial_out(up, UART_MCR, UART_MCR_LOOP | 0x0A);
-		status1 = serial_inp(up, UART_MSR) & 0xF0;
+		status1 = serial_in(up, UART_MSR) & 0xF0;
-		serial_outp(up, UART_MCR, save_mcr);
+		serial_out(up, UART_MCR, save_mcr);
 		if (status1 != 0x90)
 			goto out;	/* We failed loopback test */
 	}
-	serial_outp(up, UART_LCR, 0xBF);	/* set up for StarTech test */
+	serial_out(up, UART_LCR, 0xBF);	/* set up for StarTech test */
-	serial_outp(up, UART_EFR, 0);		/* EFR is the same as FCR */
+	serial_out(up, UART_EFR, 0);		/* EFR is the same as FCR */
-	serial_outp(up, UART_LCR, 0);
+	serial_out(up, UART_LCR, 0);
-	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
 	scratch = serial_in(up, UART_IIR) >> 6;
 	switch (scratch) {
 		case 0:
@@ -1107,19 +1083,19 @@ static void sunsu_autoconfig(struct uart_sunsu_port *up)
 	}
 	if (up->port.type == PORT_16550A) {
 		/* Check for Startech UART's */
-		serial_outp(up, UART_LCR, UART_LCR_DLAB);
+		serial_out(up, UART_LCR, UART_LCR_DLAB);
 		if (serial_in(up, UART_EFR) == 0) {
 			up->port.type = PORT_16650;
 		} else {
-			serial_outp(up, UART_LCR, 0xBF);
+			serial_out(up, UART_LCR, 0xBF);
 			if (serial_in(up, UART_EFR) == 0)
 				up->port.type = PORT_16650V2;
 		}
 	}
 	if (up->port.type == PORT_16550A) {
 		/* Check for TI 16750 */
-		serial_outp(up, UART_LCR, save_lcr | UART_LCR_DLAB);
+		serial_out(up, UART_LCR, save_lcr | UART_LCR_DLAB);
-		serial_outp(up, UART_FCR,
+		serial_out(up, UART_FCR,
 			    UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
 		scratch = serial_in(up, UART_IIR) >> 5;
 		if (scratch == 7) {
@@ -1129,24 +1105,24 @@ static void sunsu_autoconfig(struct uart_sunsu_port *up)
 			 * mode if the UART_FCR7_64BYTE bit was set
 			 * while UART_LCR_DLAB was latched.
 			 */
- 			serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+			serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
-			serial_outp(up, UART_LCR, 0);
+			serial_out(up, UART_LCR, 0);
-			serial_outp(up, UART_FCR,
+			serial_out(up, UART_FCR,
 				    UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
 			scratch = serial_in(up, UART_IIR) >> 5;
 			if (scratch == 6)
 				up->port.type = PORT_16750;
 		}
-		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+		serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
 	}
-	serial_outp(up, UART_LCR, save_lcr);
+	serial_out(up, UART_LCR, save_lcr);
 	if (up->port.type == PORT_16450) {
 		scratch = serial_in(up, UART_SCR);
-		serial_outp(up, UART_SCR, 0xa5);
+		serial_out(up, UART_SCR, 0xa5);
 		status1 = serial_in(up, UART_SCR);
-		serial_outp(up, UART_SCR, 0x5a);
+		serial_out(up, UART_SCR, 0x5a);
 		status2 = serial_in(up, UART_SCR);
-		serial_outp(up, UART_SCR, scratch);
+		serial_out(up, UART_SCR, scratch);
 
 		if ((status1 != 0xa5) || (status2 != 0x5a))
 			up->port.type = PORT_8250;
@@ -1163,15 +1139,15 @@ static void sunsu_autoconfig(struct uart_sunsu_port *up)
 	 */
 #ifdef CONFIG_SERIAL_8250_RSA
 	if (up->port.type == PORT_RSA)
-		serial_outp(up, UART_RSA_FRR, 0);
+		serial_out(up, UART_RSA_FRR, 0);
 #endif
-	serial_outp(up, UART_MCR, save_mcr);
+	serial_out(up, UART_MCR, save_mcr);
-	serial_outp(up, UART_FCR, (UART_FCR_ENABLE_FIFO |
+	serial_out(up, UART_FCR, (UART_FCR_ENABLE_FIFO |
 				     UART_FCR_CLEAR_RCVR |
 				     UART_FCR_CLEAR_XMIT));
-	serial_outp(up, UART_FCR, 0);
+	serial_out(up, UART_FCR, 0);
 	(void)serial_in(up, UART_RX);
-	serial_outp(up, UART_IER, 0);
+	serial_out(up, UART_IER, 0);
 
 out:
 	uart_port_unlock_irqrestore(&up->port, flags);

drivers/tty/serial/tegra-utc.c

@@ -0,0 +1,625 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// NVIDIA Tegra UTC (UART Trace Controller) driver.
+
+#include <linux/bits.h>
+#include <linux/console.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/iopoll.h>
+#include <linux/kfifo.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/types.h>
+
+#define TEGRA_UTC_ENABLE			0x000
+#define TEGRA_UTC_ENABLE_CLIENT_ENABLE		BIT(0)
+
+#define TEGRA_UTC_FIFO_THRESHOLD		0x008
+
+#define TEGRA_UTC_COMMAND			0x00c
+#define TEGRA_UTC_COMMAND_RESET			BIT(0)
+#define TEGRA_UTC_COMMAND_FLUSH			BIT(1)
+
+#define TEGRA_UTC_DATA				0x020
+
+#define TEGRA_UTC_FIFO_STATUS			0x100
+#define TEGRA_UTC_FIFO_EMPTY			BIT(0)
+#define TEGRA_UTC_FIFO_FULL			BIT(1)
+#define TEGRA_UTC_FIFO_REQ			BIT(2)
+#define TEGRA_UTC_FIFO_OVERFLOW			BIT(3)
+#define TEGRA_UTC_FIFO_TIMEOUT			BIT(4)
+
+#define TEGRA_UTC_FIFO_OCCUPANCY		0x104
+
+#define TEGRA_UTC_INTR_STATUS			0x108
+#define TEGRA_UTC_INTR_SET			0x10c
+#define TEGRA_UTC_INTR_MASK			0x110
+#define TEGRA_UTC_INTR_CLEAR			0x114
+#define TEGRA_UTC_INTR_EMPTY			BIT(0)
+#define TEGRA_UTC_INTR_FULL			BIT(1)
+#define TEGRA_UTC_INTR_REQ			BIT(2)
+#define TEGRA_UTC_INTR_OVERFLOW			BIT(3)
+#define TEGRA_UTC_INTR_TIMEOUT			BIT(4)
+
+#define TEGRA_UTC_UART_NR			16
+
+#define TEGRA_UTC_INTR_COMMON	(TEGRA_UTC_INTR_REQ | TEGRA_UTC_INTR_FULL | TEGRA_UTC_INTR_EMPTY)
+
+struct tegra_utc_port {
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+	struct console console;
+#endif
+	struct uart_port port;
+
+	void __iomem *rx_base;
+	void __iomem *tx_base;
+
+	u32 tx_irqmask;
+	u32 rx_irqmask;
+
+	unsigned int fifosize;
+	u32 tx_threshold;
+	u32 rx_threshold;
+};
+
+static u32 tegra_utc_rx_readl(struct tegra_utc_port *tup, unsigned int offset)
+{
+	void __iomem *addr = tup->rx_base + offset;
+
+	return readl_relaxed(addr);
+}
+
+static void tegra_utc_rx_writel(struct tegra_utc_port *tup, u32 val, unsigned int offset)
+{
+	void __iomem *addr = tup->rx_base + offset;
+
+	writel_relaxed(val, addr);
+}
+
+static u32 tegra_utc_tx_readl(struct tegra_utc_port *tup, unsigned int offset)
+{
+	void __iomem *addr = tup->tx_base + offset;
+
+	return readl_relaxed(addr);
+}
+
+static void tegra_utc_tx_writel(struct tegra_utc_port *tup, u32 val, unsigned int offset)
+{
+	void __iomem *addr = tup->tx_base + offset;
+
+	writel_relaxed(val, addr);
+}
+
+static void tegra_utc_enable_tx_irq(struct tegra_utc_port *tup)
+{
+	tup->tx_irqmask = TEGRA_UTC_INTR_REQ;
+
+	tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_MASK);
+	tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_SET);
+}
+
+static void tegra_utc_disable_tx_irq(struct tegra_utc_port *tup)
+{
+	tup->tx_irqmask = 0x0;
+
+	tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_MASK);
+	tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_SET);
+}
+
+static void tegra_utc_stop_tx(struct uart_port *port)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+	tegra_utc_disable_tx_irq(tup);
+}
+
+static void tegra_utc_init_tx(struct tegra_utc_port *tup)
+{
+	/* Disable TX. */
+	tegra_utc_tx_writel(tup, 0x0, TEGRA_UTC_ENABLE);
+
+	/* Update the FIFO Threshold. */
+	tegra_utc_tx_writel(tup, tup->tx_threshold, TEGRA_UTC_FIFO_THRESHOLD);
+
+	/* Clear and mask all the interrupts. */
+	tegra_utc_tx_writel(tup, TEGRA_UTC_INTR_COMMON, TEGRA_UTC_INTR_CLEAR);
+	tegra_utc_disable_tx_irq(tup);
+
+	/* Enable TX. */
+	tegra_utc_tx_writel(tup, TEGRA_UTC_ENABLE_CLIENT_ENABLE, TEGRA_UTC_ENABLE);
+}
+
+static void tegra_utc_init_rx(struct tegra_utc_port *tup)
+{
+	tup->rx_irqmask = TEGRA_UTC_INTR_REQ | TEGRA_UTC_INTR_TIMEOUT;
+
+	tegra_utc_rx_writel(tup, TEGRA_UTC_COMMAND_RESET, TEGRA_UTC_COMMAND);
+	tegra_utc_rx_writel(tup, tup->rx_threshold, TEGRA_UTC_FIFO_THRESHOLD);
+
+	/* Clear all the pending interrupts. */
+	tegra_utc_rx_writel(tup, TEGRA_UTC_INTR_TIMEOUT | TEGRA_UTC_INTR_OVERFLOW |
+			    TEGRA_UTC_INTR_COMMON, TEGRA_UTC_INTR_CLEAR);
+	tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_MASK);
+	tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_SET);
+
+	/* Enable RX. */
+	tegra_utc_rx_writel(tup, TEGRA_UTC_ENABLE_CLIENT_ENABLE, TEGRA_UTC_ENABLE);
+}
+
+static bool tegra_utc_tx_chars(struct tegra_utc_port *tup)
+{
+	struct uart_port *port = &tup->port;
+	unsigned int pending;
+	u8 c;
+
+	pending = uart_port_tx(port, c,
+		     !(tegra_utc_tx_readl(tup, TEGRA_UTC_FIFO_STATUS) & TEGRA_UTC_FIFO_FULL),
+		     tegra_utc_tx_writel(tup, c, TEGRA_UTC_DATA));
+
+	return pending;
+}
+
+static void tegra_utc_rx_chars(struct tegra_utc_port *tup)
+{
+	struct tty_port *port = &tup->port.state->port;
+	unsigned int max_chars = 256;
+	u32 status;
+	int sysrq;
+	u32 ch;
+
+	while (max_chars--) {
+		status = tegra_utc_rx_readl(tup, TEGRA_UTC_FIFO_STATUS);
+		if (status & TEGRA_UTC_FIFO_EMPTY)
+			break;
+
+		ch = tegra_utc_rx_readl(tup, TEGRA_UTC_DATA);
+		tup->port.icount.rx++;
+
+		if (status & TEGRA_UTC_FIFO_OVERFLOW)
+			tup->port.icount.overrun++;
+
+		uart_port_unlock(&tup->port);
+		sysrq = uart_handle_sysrq_char(&tup->port, ch);
+		uart_port_lock(&tup->port);
+
+		if (!sysrq)
+			tty_insert_flip_char(port, ch, TTY_NORMAL);
+	}
+
+	tty_flip_buffer_push(port);
+}
+
+static irqreturn_t tegra_utc_isr(int irq, void *dev_id)
+{
+	struct tegra_utc_port *tup = dev_id;
+	unsigned int handled = 0;
+	u32 status;
+
+	uart_port_lock(&tup->port);
+
+	/* Process RX_REQ and RX_TIMEOUT interrupts. */
+	do {
+		status = tegra_utc_rx_readl(tup, TEGRA_UTC_INTR_STATUS) & tup->rx_irqmask;
+		if (status) {
+			tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_CLEAR);
+			tegra_utc_rx_chars(tup);
+			handled = 1;
+		}
+	} while (status);
+
+	/* Process TX_REQ interrupt. */
+	do {
+		status = tegra_utc_tx_readl(tup, TEGRA_UTC_INTR_STATUS) & tup->tx_irqmask;
+		if (status) {
+			tegra_utc_tx_writel(tup, tup->tx_irqmask, TEGRA_UTC_INTR_CLEAR);
+			tegra_utc_tx_chars(tup);
+			handled = 1;
+		}
+	} while (status);
+
+	uart_port_unlock(&tup->port);
+
+	return IRQ_RETVAL(handled);
+}
+
+static unsigned int tegra_utc_tx_empty(struct uart_port *port)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+	return tegra_utc_tx_readl(tup, TEGRA_UTC_FIFO_OCCUPANCY) ? 0 : TIOCSER_TEMT;
+}
+
+static void tegra_utc_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int tegra_utc_get_mctrl(struct uart_port *port)
+{
+	return 0;
+}
+
+static void tegra_utc_start_tx(struct uart_port *port)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+	if (tegra_utc_tx_chars(tup))
+		tegra_utc_enable_tx_irq(tup);
+}
+
+static void tegra_utc_stop_rx(struct uart_port *port)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+	tup->rx_irqmask = 0x0;
+	tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_MASK);
+	tegra_utc_rx_writel(tup, tup->rx_irqmask, TEGRA_UTC_INTR_SET);
+}
+
+static void tegra_utc_hw_init(struct tegra_utc_port *tup)
+{
+	tegra_utc_init_tx(tup);
+	tegra_utc_init_rx(tup);
+}
+
+static int tegra_utc_startup(struct uart_port *port)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+	int ret;
+
+	tegra_utc_hw_init(tup);
+
+	/* Interrupt is dedicated to this UTC client. */
+	ret = request_irq(port->irq, tegra_utc_isr, 0, dev_name(port->dev), tup);
+	if (ret < 0)
+		dev_err(port->dev, "failed to register interrupt handler\n");
+
+	return ret;
+}
+
+static void tegra_utc_shutdown(struct uart_port *port)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+	tegra_utc_rx_writel(tup, 0x0, TEGRA_UTC_ENABLE);
+	free_irq(port->irq, tup);
+}
+
+static void tegra_utc_set_termios(struct uart_port *port, struct ktermios *termios,
+				  const struct ktermios *old)
+{
+	/* The Tegra UTC clients supports only 8-N-1 configuration without HW flow control */
+	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
+	termios->c_cflag &= ~(CMSPAR | CRTSCTS);
+	termios->c_cflag |= CS8 | CLOCAL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static int tegra_utc_poll_init(struct uart_port *port)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+	tegra_utc_hw_init(tup);
+	return 0;
+}
+
+static int tegra_utc_get_poll_char(struct uart_port *port)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+	if (tegra_utc_rx_readl(tup, TEGRA_UTC_FIFO_STATUS) & TEGRA_UTC_FIFO_EMPTY)
+		return NO_POLL_CHAR;
+
+	return tegra_utc_rx_readl(tup, TEGRA_UTC_DATA);
+}
+
+static void tegra_utc_put_poll_char(struct uart_port *port, unsigned char ch)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+	u32 val;
+
+	read_poll_timeout_atomic(tegra_utc_tx_readl, val, !(val & TEGRA_UTC_FIFO_FULL),
+				 0, USEC_PER_SEC, false, tup, TEGRA_UTC_FIFO_STATUS);
+
+	tegra_utc_tx_writel(tup, ch, TEGRA_UTC_DATA);
+}
+
+#endif
+
+static const struct uart_ops tegra_utc_uart_ops = {
+	.tx_empty = tegra_utc_tx_empty,
+	.set_mctrl = tegra_utc_set_mctrl,
+	.get_mctrl = tegra_utc_get_mctrl,
+	.stop_tx = tegra_utc_stop_tx,
+	.start_tx = tegra_utc_start_tx,
+	.stop_rx = tegra_utc_stop_rx,
+	.startup = tegra_utc_startup,
+	.shutdown = tegra_utc_shutdown,
+	.set_termios = tegra_utc_set_termios,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_init = tegra_utc_poll_init,
+	.poll_get_char = tegra_utc_get_poll_char,
+	.poll_put_char = tegra_utc_put_poll_char,
+#endif
+};
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+#define TEGRA_UTC_DEFAULT_FIFO_THRESHOLD	4
+#define TEGRA_UTC_EARLYCON_MAX_BURST_SIZE	128
+
+static void tegra_utc_putc(struct uart_port *port, unsigned char c)
+{
+	writel(c, port->membase + TEGRA_UTC_DATA);
+}
+
+static void tegra_utc_early_write(struct console *con, const char *s, unsigned int n)
+{
+	struct earlycon_device *dev = con->data;
+
+	while (n) {
+		u32 burst_size = TEGRA_UTC_EARLYCON_MAX_BURST_SIZE;
+
+		burst_size -= readl(dev->port.membase + TEGRA_UTC_FIFO_OCCUPANCY);
+		if (n < burst_size)
+			burst_size = n;
+
+		uart_console_write(&dev->port, s, burst_size, tegra_utc_putc);
+
+		n -= burst_size;
+		s += burst_size;
+	}
+}
+
+static int __init tegra_utc_early_console_setup(struct earlycon_device *device, const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	/* Configure TX */
+	writel(TEGRA_UTC_COMMAND_FLUSH | TEGRA_UTC_COMMAND_RESET,
+		device->port.membase + TEGRA_UTC_COMMAND);
+	writel(TEGRA_UTC_DEFAULT_FIFO_THRESHOLD, device->port.membase + TEGRA_UTC_FIFO_THRESHOLD);
+
+	/* Clear and mask all the interrupts. */
+	writel(TEGRA_UTC_INTR_COMMON, device->port.membase + TEGRA_UTC_INTR_CLEAR);
+
+	writel(0x0, device->port.membase + TEGRA_UTC_INTR_MASK);
+	writel(0x0, device->port.membase + TEGRA_UTC_INTR_SET);
+
+	/* Enable TX. */
+	writel(TEGRA_UTC_ENABLE_CLIENT_ENABLE, device->port.membase + TEGRA_UTC_ENABLE);
+
+	device->con->write = tegra_utc_early_write;
+
+	return 0;
+}
+OF_EARLYCON_DECLARE(tegra_utc, "nvidia,tegra264-utc", tegra_utc_early_console_setup);
+
+static void tegra_utc_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct tegra_utc_port *tup = container_of(port, struct tegra_utc_port, port);
+
+	tegra_utc_tx_writel(tup, ch, TEGRA_UTC_DATA);
+}
+
+static void tegra_utc_console_write_atomic(struct console *cons, struct nbcon_write_context *wctxt)
+{
+	struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+	unsigned int len;
+	char *outbuf;
+
+	if (!nbcon_enter_unsafe(wctxt))
+		return;
+
+	outbuf = wctxt->outbuf;
+	len = wctxt->len;
+
+	while (len) {
+		u32 burst_size = tup->fifosize;
+
+		burst_size -= tegra_utc_tx_readl(tup, TEGRA_UTC_FIFO_OCCUPANCY);
+		if (len < burst_size)
+			burst_size = len;
+
+		uart_console_write(&tup->port, outbuf, burst_size, tegra_utc_console_putchar);
+
+		outbuf += burst_size;
+		len -= burst_size;
+	};
+
+	nbcon_exit_unsafe(wctxt);
+}
+
+static void tegra_utc_console_write_thread(struct console *cons, struct nbcon_write_context *wctxt)
+{
+	struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+	unsigned int len = READ_ONCE(wctxt->len);
+	unsigned int i;
+	u32 val;
+
+	for (i = 0; i < len; i++) {
+		if (!nbcon_enter_unsafe(wctxt))
+			break;
+
+		read_poll_timeout_atomic(tegra_utc_tx_readl, val, !(val & TEGRA_UTC_FIFO_FULL),
+					 0, USEC_PER_SEC, false, tup, TEGRA_UTC_FIFO_STATUS);
+		uart_console_write(&tup->port, wctxt->outbuf + i, 1, tegra_utc_console_putchar);
+
+		if (!nbcon_exit_unsafe(wctxt))
+			break;
+	}
+}
+
+static void tegra_utc_console_device_lock(struct console *cons, unsigned long *flags)
+{
+	struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+	struct uart_port *port = &tup->port;
+
+	__uart_port_lock_irqsave(port, flags);
+}
+
+static void tegra_utc_console_device_unlock(struct console *cons, unsigned long flags)
+{
+	struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+	struct uart_port *port = &tup->port;
+
+	__uart_port_unlock_irqrestore(port, flags);
+}
+
+static int tegra_utc_console_setup(struct console *cons, char *options)
+{
+	struct tegra_utc_port *tup = container_of(cons, struct tegra_utc_port, console);
+
+	tegra_utc_init_tx(tup);
+
+	return 0;
+}
+#endif
+
+static struct uart_driver tegra_utc_driver = {
+	.driver_name	= "tegra-utc",
+	.dev_name	= "ttyUTC",
+	.nr		= TEGRA_UTC_UART_NR,
+};
+
+static int tegra_utc_setup_port(struct device *dev, struct tegra_utc_port *tup)
+{
+	tup->port.dev			= dev;
+	tup->port.fifosize		= tup->fifosize;
+	tup->port.flags			= UPF_BOOT_AUTOCONF;
+	tup->port.iotype		= UPIO_MEM;
+	tup->port.ops			= &tegra_utc_uart_ops;
+	tup->port.type			= PORT_TEGRA_TCU;
+	tup->port.private_data		= tup;
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+	strscpy(tup->console.name, "ttyUTC", sizeof(tup->console.name));
+	tup->console.write_atomic	= tegra_utc_console_write_atomic;
+	tup->console.write_thread	= tegra_utc_console_write_thread;
+	tup->console.device_lock	= tegra_utc_console_device_lock;
+	tup->console.device_unlock	= tegra_utc_console_device_unlock;
+	tup->console.device		= uart_console_device;
+	tup->console.setup		= tegra_utc_console_setup;
+	tup->console.flags		= CON_PRINTBUFFER | CON_NBCON;
+	tup->console.data		= &tegra_utc_driver;
+#endif
+
+	return uart_read_port_properties(&tup->port);
+}
+
+static int tegra_utc_register_port(struct tegra_utc_port *tup)
+{
+	int ret;
+
+	ret = uart_add_one_port(&tegra_utc_driver, &tup->port);
+	if (ret)
+		return ret;
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+	register_console(&tup->console);
+#endif
+
+	return 0;
+}
+
+static int tegra_utc_probe(struct platform_device *pdev)
+{
+	const unsigned int *soc_fifosize;
+	struct device *dev = &pdev->dev;
+	struct tegra_utc_port *tup;
+	int ret;
+
+	tup = devm_kzalloc(dev, sizeof(*tup), GFP_KERNEL);
+	if (!tup)
+		return -ENOMEM;
+
+	ret = device_property_read_u32(dev, "tx-threshold", &tup->tx_threshold);
+	if (ret)
+		return dev_err_probe(dev, ret, "missing %s property\n", "tx-threshold");
+
+	ret = device_property_read_u32(dev, "rx-threshold", &tup->rx_threshold);
+	if (ret)
+		return dev_err_probe(dev, ret, "missing %s property\n", "rx-threshold");
+
+	soc_fifosize = device_get_match_data(dev);
+	tup->fifosize = *soc_fifosize;
+
+	tup->tx_base = devm_platform_ioremap_resource_byname(pdev, "tx");
+	if (IS_ERR(tup->tx_base))
+		return PTR_ERR(tup->tx_base);
+
+	tup->rx_base = devm_platform_ioremap_resource_byname(pdev, "rx");
+	if (IS_ERR(tup->rx_base))
+		return PTR_ERR(tup->rx_base);
+
+	ret = tegra_utc_setup_port(dev, tup);
+	if (ret)
+		dev_err_probe(dev, ret, "failed to setup uart port\n");
+
+	platform_set_drvdata(pdev, tup);
+
+	return tegra_utc_register_port(tup);
+}
+
+static void tegra_utc_remove(struct platform_device *pdev)
+{
+	struct tegra_utc_port *tup = platform_get_drvdata(pdev);
+
+#if IS_ENABLED(CONFIG_SERIAL_TEGRA_UTC_CONSOLE)
+	unregister_console(&tup->console);
+#endif
+	uart_remove_one_port(&tegra_utc_driver, &tup->port);
+}
+
+static const unsigned int tegra264_utc_soc = 128;
+
+static const struct of_device_id tegra_utc_of_match[] = {
+	{ .compatible = "nvidia,tegra264-utc", .data = &tegra264_utc_soc },
+	{}
+};
+MODULE_DEVICE_TABLE(of, tegra_utc_of_match);
+
+static struct platform_driver tegra_utc_platform_driver = {
+	.probe = tegra_utc_probe,
+	.remove = tegra_utc_remove,
+	.driver = {
+		.name = "tegra-utc",
+		.of_match_table = tegra_utc_of_match,
+	},
+};
+
+static int __init tegra_utc_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&tegra_utc_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&tegra_utc_platform_driver);
+	if (ret)
+		uart_unregister_driver(&tegra_utc_driver);
+
+	return ret;
+}
+module_init(tegra_utc_init);
+
+static void __exit tegra_utc_exit(void)
+{
+	platform_driver_unregister(&tegra_utc_platform_driver);
+	uart_unregister_driver(&tegra_utc_driver);
+}
+module_exit(tegra_utc_exit);
+
+MODULE_AUTHOR("Kartik Rajput <kkartik@nvidia.com>");
+MODULE_DESCRIPTION("Tegra UART Trace Controller");
+MODULE_LICENSE("GPL");

drivers/tty/tty_audit.c

@@ -12,12 +12,14 @@
 #include <linux/tty.h>
 #include "tty.h"
 
+#define TTY_AUDIT_BUF_SIZE	4096
+
 struct tty_audit_buf {
 	struct mutex mutex;	/* Protects all data below */
 	dev_t dev;		/* The TTY which the data is from */
 	bool icanon;
 	size_t valid;
-	u8 *data;		/* Allocated size N_TTY_BUF_SIZE */
+	u8 *data;		/* Allocated size TTY_AUDIT_BUF_SIZE */
 };
 
 static struct tty_audit_buf *tty_audit_buf_ref(void)
@@ -37,7 +39,7 @@ static struct tty_audit_buf *tty_audit_buf_alloc(void)
 	if (!buf)
 		goto err;
 
-	buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+	buf->data = kmalloc(TTY_AUDIT_BUF_SIZE, GFP_KERNEL);
 	if (!buf->data)
 		goto err_buf;
 
@@ -235,14 +237,14 @@ void tty_audit_add_data(const struct tty_struct *tty, const void *data,
 	do {
 		size_t run;
 
-		run = N_TTY_BUF_SIZE - buf->valid;
+		run = TTY_AUDIT_BUF_SIZE - buf->valid;
 		if (run > size)
 			run = size;
 		memcpy(buf->data + buf->valid, data, run);
 		buf->valid += run;
 		data += run;
 		size -= run;
-		if (buf->valid == N_TTY_BUF_SIZE)
+		if (buf->valid == TTY_AUDIT_BUF_SIZE)
 			tty_audit_buf_push(buf);
 	} while (size != 0);
 	mutex_unlock(&buf->mutex);

drivers/tty/tty_io.c

@@ -3329,10 +3329,12 @@ EXPORT_SYMBOL(tty_unregister_device);
  * __tty_alloc_driver - allocate tty driver
  * @lines: count of lines this driver can handle at most
  * @owner: module which is responsible for this driver
- * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags
+ * @flags: some of enum tty_driver_flag, will be set in driver->flags
  *
- * This should not be called directly, some of the provided macros should be
+ * This should not be called directly, tty_alloc_driver() should be used
- * used instead. Use IS_ERR() and friends on @retval.
+ * instead.
+ *
+ * Returns: struct tty_driver or a PTR-encoded error (use IS_ERR() and friends).
  */
 struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
 		unsigned long flags)

drivers/tty/tty_ldsem.c

@@ -366,23 +366,6 @@ int __sched ldsem_down_write(struct ld_semaphore *sem, long timeout)
 	return __ldsem_down_write_nested(sem, 0, timeout);
 }
 
-/*
- * trylock for writing -- returns 1 if successful, 0 if contention
- */
-int ldsem_down_write_trylock(struct ld_semaphore *sem)
-{
-	long count = atomic_long_read(&sem->count);
-
-	while ((count & LDSEM_ACTIVE_MASK) == 0) {
-		if (atomic_long_try_cmpxchg(&sem->count, &count, count + LDSEM_WRITE_BIAS)) {
-			rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_);
-			lock_acquired(&sem->dep_map, _RET_IP_);
-			return 1;
-		}
-	}
-	return 0;
-}
-
 /*
  * release a read lock
  */

include/linux/kgdb.h

@@ -257,7 +257,6 @@ extern void kgdb_arch_late(void);
  * hardware breakpoints.
  * @correct_hw_break: Allow an architecture to specify how to correct the
  * hardware debug registers.
- * @enable_nmi: Manage NMI-triggered entry to KGDB
  */
 struct kgdb_arch {
 	unsigned char		gdb_bpt_instr[BREAK_INSTR_SIZE];
@@ -270,8 +269,6 @@ struct kgdb_arch {
 	void	(*disable_hw_break)(struct pt_regs *regs);
 	void	(*remove_all_hw_break)(void);
 	void	(*correct_hw_break)(void);
-
-	void	(*enable_nmi)(bool on);
 };
 
 /**
@@ -306,14 +303,6 @@ extern const struct kgdb_arch		arch_kgdb_ops;
 
 extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);
 
-#ifdef CONFIG_SERIAL_KGDB_NMI
-extern int kgdb_register_nmi_console(void);
-extern int kgdb_unregister_nmi_console(void);
-#else
-static inline int kgdb_register_nmi_console(void) { return 0; }
-static inline int kgdb_unregister_nmi_console(void) { return 0; }
-#endif
-
 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
 extern struct kgdb_io *dbg_io_ops;

include/linux/serdev.h

@@ -84,7 +84,6 @@ enum serdev_parity {
 struct serdev_controller_ops {
 	ssize_t (*write_buf)(struct serdev_controller *, const u8 *, size_t);
 	void (*write_flush)(struct serdev_controller *);
-	int (*write_room)(struct serdev_controller *);
 	int (*open)(struct serdev_controller *);
 	void (*close)(struct serdev_controller *);
 	void (*set_flow_control)(struct serdev_controller *, bool);
@@ -212,7 +211,6 @@ int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
 void serdev_device_write_wakeup(struct serdev_device *);
 ssize_t serdev_device_write(struct serdev_device *, const u8 *, size_t, long);
 void serdev_device_write_flush(struct serdev_device *);
-int serdev_device_write_room(struct serdev_device *);
 
 /*
  * serdev device driver functions
@@ -273,10 +271,6 @@ static inline ssize_t serdev_device_write(struct serdev_device *sdev,
 	return -ENODEV;
 }
 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
-static inline int serdev_device_write_room(struct serdev_device *sdev)
-{
-	return 0;
-}
 
 #define serdev_device_driver_register(x)
 #define serdev_device_driver_unregister(x)

include/linux/tty.h

@@ -239,7 +239,6 @@ struct tty_struct {
 
 	struct list_head tty_files;
 
-#define N_TTY_BUF_SIZE 4096
 	struct work_struct SAK_work;
 } __randomize_layout;
 
@@ -251,7 +250,7 @@ struct tty_file_private {
 };
 
 /**
- * DOC: TTY Struct Flags
+ * enum tty_struct_flags - TTY Struct Flags
  *
  * These bits are used in the :c:member:`tty_struct.flags` field.
  *
@@ -260,62 +259,64 @@ struct tty_file_private {
  * tty->write.  Thus, you must use the inline functions set_bit() and
  * clear_bit() to make things atomic.
  *
- * TTY_THROTTLED
+ * @TTY_THROTTLED:
  *	Driver input is throttled. The ldisc should call
  *	:c:member:`tty_driver.unthrottle()` in order to resume reception when
  *	it is ready to process more data (at threshold min).
  *
- * TTY_IO_ERROR
+ * @TTY_IO_ERROR:
  *	If set, causes all subsequent userspace read/write calls on the tty to
  *	fail, returning -%EIO. (May be no ldisc too.)
  *
- * TTY_OTHER_CLOSED
+ * @TTY_OTHER_CLOSED:
  *	Device is a pty and the other side has closed.
  *
- * TTY_EXCLUSIVE
+ * @TTY_EXCLUSIVE:
  *	Exclusive open mode (a single opener).
  *
- * TTY_DO_WRITE_WAKEUP
+ * @TTY_DO_WRITE_WAKEUP:
  *	If set, causes the driver to call the
  *	:c:member:`tty_ldisc_ops.write_wakeup()` method in order to resume
  *	transmission when it can accept more data to transmit.
  *
- * TTY_LDISC_OPEN
+ * @TTY_LDISC_OPEN:
  *	Indicates that a line discipline is open. For debugging purposes only.
  *
- * TTY_PTY_LOCK
+ * @TTY_PTY_LOCK:
  *	A flag private to pty code to implement %TIOCSPTLCK/%TIOCGPTLCK logic.
  *
- * TTY_NO_WRITE_SPLIT
+ * @TTY_NO_WRITE_SPLIT:
  *	Prevent driver from splitting up writes into smaller chunks (preserve
  *	write boundaries to driver).
  *
- * TTY_HUPPED
+ * @TTY_HUPPED:
  *	The TTY was hung up. This is set post :c:member:`tty_driver.hangup()`.
  *
- * TTY_HUPPING
+ * @TTY_HUPPING:
  *	The TTY is in the process of hanging up to abort potential readers.
  *
- * TTY_LDISC_CHANGING
+ * @TTY_LDISC_CHANGING:
  *	Line discipline for this TTY is being changed. I/O should not block
  *	when this is set. Use tty_io_nonblock() to check.
  *
- * TTY_LDISC_HALTED
+ * @TTY_LDISC_HALTED:
  *	Line discipline for this TTY was stopped. No work should be queued to
  *	this ldisc.
  */
-#define TTY_THROTTLED		0
+enum tty_struct_flags {
-#define TTY_IO_ERROR		1
+	TTY_THROTTLED,
-#define TTY_OTHER_CLOSED	2
+	TTY_IO_ERROR,
-#define TTY_EXCLUSIVE		3
+	TTY_OTHER_CLOSED,
-#define TTY_DO_WRITE_WAKEUP	5
+	TTY_EXCLUSIVE,
-#define TTY_LDISC_OPEN		11
+	TTY_DO_WRITE_WAKEUP,
-#define TTY_PTY_LOCK		16
+	TTY_LDISC_OPEN,
-#define TTY_NO_WRITE_SPLIT	17
+	TTY_PTY_LOCK,
-#define TTY_HUPPED		18
+	TTY_NO_WRITE_SPLIT,
-#define TTY_HUPPING		19
+	TTY_HUPPED,
-#define TTY_LDISC_CHANGING	20
+	TTY_HUPPING,
-#define TTY_LDISC_HALTED	22
+	TTY_LDISC_CHANGING,
+	TTY_LDISC_HALTED,
+};
 
 static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
 {

include/linux/tty_driver.h

@@ -16,6 +16,92 @@ struct tty_driver;
 struct serial_icounter_struct;
 struct serial_struct;
 
+/**
+ * enum tty_driver_flag -- TTY Driver Flags
+ *
+ * These are flags passed to tty_alloc_driver().
+ *
+ * @TTY_DRIVER_INSTALLED:
+ *	Whether this driver was succesfully installed. This is a tty internal
+ *	flag. Do not touch.
+ *
+ * @TTY_DRIVER_RESET_TERMIOS:
+ *	Requests the tty layer to reset the termios setting when the last
+ *	process has closed the device. Used for PTYs, in particular.
+ *
+ * @TTY_DRIVER_REAL_RAW:
+ *	Indicates that the driver will guarantee not to set any special
+ *	character handling flags if this is set for the tty:
+ *
+ *	``(IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || !INPCK)``
+ *
+ *	That is, if there is no reason for the driver to
+ *	send notifications of parity and break characters up to the line
+ *	driver, it won't do so.  This allows the line driver to optimize for
+ *	this case if this flag is set.  (Note that there is also a promise, if
+ *	the above case is true, not to signal overruns, either.)
+ *
+ * @TTY_DRIVER_DYNAMIC_DEV:
+ *	The individual tty devices need to be registered with a call to
+ *	tty_register_device() when the device is found in the system and
+ *	unregistered with a call to tty_unregister_device() so the devices will
+ *	be show up properly in sysfs.  If not set, all &tty_driver.num entries
+ *	will be created by the tty core in sysfs when tty_register_driver() is
+ *	called.  This is to be used by drivers that have tty devices that can
+ *	appear and disappear while the main tty driver is registered with the
+ *	tty core.
+ *
+ * @TTY_DRIVER_DEVPTS_MEM:
+ *	Don't use the standard arrays (&tty_driver.ttys and
+ *	&tty_driver.termios), instead use dynamic memory keyed through the
+ *	devpts filesystem. This is only applicable to the PTY driver.
+ *
+ * @TTY_DRIVER_HARDWARE_BREAK:
+ *	Hardware handles break signals. Pass the requested timeout to the
+ *	&tty_operations.break_ctl instead of using a simple on/off interface.
+ *
+ * @TTY_DRIVER_DYNAMIC_ALLOC:
+ *	Do not allocate structures which are needed per line for this driver
+ *	(&tty_driver.ports) as it would waste memory. The driver will take
+ *	care. This is only applicable to the PTY driver.
+ *
+ * @TTY_DRIVER_UNNUMBERED_NODE:
+ *	Do not create numbered ``/dev`` nodes. For example, create
+ *	``/dev/ttyprintk`` and not ``/dev/ttyprintk0``. Applicable only when a
+ *	driver for a single tty device is being allocated.
+ */
+enum tty_driver_flag {
+	TTY_DRIVER_INSTALLED		= BIT(0),
+	TTY_DRIVER_RESET_TERMIOS	= BIT(1),
+	TTY_DRIVER_REAL_RAW		= BIT(2),
+	TTY_DRIVER_DYNAMIC_DEV		= BIT(3),
+	TTY_DRIVER_DEVPTS_MEM		= BIT(4),
+	TTY_DRIVER_HARDWARE_BREAK	= BIT(5),
+	TTY_DRIVER_DYNAMIC_ALLOC	= BIT(6),
+	TTY_DRIVER_UNNUMBERED_NODE	= BIT(7),
+};
+
+enum tty_driver_type {
+	TTY_DRIVER_TYPE_SYSTEM,
+	TTY_DRIVER_TYPE_CONSOLE,
+	TTY_DRIVER_TYPE_SERIAL,
+	TTY_DRIVER_TYPE_PTY,
+	TTY_DRIVER_TYPE_SCC,
+	TTY_DRIVER_TYPE_SYSCONS,
+};
+
+enum tty_driver_subtype {
+	SYSTEM_TYPE_TTY = 1,
+	SYSTEM_TYPE_CONSOLE,
+	SYSTEM_TYPE_SYSCONS,
+	SYSTEM_TYPE_SYSPTMX,
+
+	PTY_TYPE_MASTER = 1,
+	PTY_TYPE_SLAVE,
+
+	SERIAL_TYPE_NORMAL = 1,
+};
+
 /**
  * struct tty_operations -- interface between driver and tty
  *
@@ -414,8 +500,8 @@ struct tty_operations {
  * @major: major /dev device number (zero for autoassignment)
  * @minor_start: the first minor /dev device number
  * @num: number of devices allocated
- * @type: type of tty driver (%TTY_DRIVER_TYPE_)
+ * @type: type of tty driver (enum tty_driver_type)
- * @subtype: subtype of tty driver (%SYSTEM_TYPE_, %PTY_TYPE_, %SERIAL_TYPE_)
+ * @subtype: subtype of tty driver (enum tty_driver_subtype)
  * @init_termios: termios to set to each tty initially (e.g. %tty_std_termios)
  * @flags: tty driver flags (%TTY_DRIVER_)
  * @proc_entry: proc fs entry, used internally
@@ -447,8 +533,8 @@ struct tty_driver {
 	int	major;
 	int	minor_start;
 	unsigned int	num;
-	short	type;
+	enum tty_driver_type type;
-	short	subtype;
+	enum tty_driver_subtype subtype;
 	struct ktermios init_termios;
 	unsigned long	flags;
 	struct proc_dir_entry *proc_entry;
@@ -478,7 +564,13 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line);
 
 void tty_driver_kref_put(struct tty_driver *driver);
 
-/* Use TTY_DRIVER_* flags below */
+/**
+ * tty_alloc_driver - allocate tty driver
+ * @lines: count of lines this driver can handle at most
+ * @flags: some of enum tty_driver_flag, will be set in driver->flags
+ *
+ * Returns: struct tty_driver or a PTR-encoded error (use IS_ERR() and friends).
+ */
 #define tty_alloc_driver(lines, flags) \
 		__tty_alloc_driver(lines, THIS_MODULE, flags)
 
@@ -494,84 +586,6 @@ static inline void tty_set_operations(struct tty_driver *driver,
 	driver->ops = op;
 }
 
-/**
- * DOC: TTY Driver Flags
- *
- * TTY_DRIVER_RESET_TERMIOS
- *	Requests the tty layer to reset the termios setting when the last
- *	process has closed the device. Used for PTYs, in particular.
- *
- * TTY_DRIVER_REAL_RAW
- *	Indicates that the driver will guarantee not to set any special
- *	character handling flags if this is set for the tty:
- *
- *	``(IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || !INPCK)``
- *
- *	That is, if there is no reason for the driver to
- *	send notifications of parity and break characters up to the line
- *	driver, it won't do so.  This allows the line driver to optimize for
- *	this case if this flag is set.  (Note that there is also a promise, if
- *	the above case is true, not to signal overruns, either.)
- *
- * TTY_DRIVER_DYNAMIC_DEV
- *	The individual tty devices need to be registered with a call to
- *	tty_register_device() when the device is found in the system and
- *	unregistered with a call to tty_unregister_device() so the devices will
- *	be show up properly in sysfs.  If not set, all &tty_driver.num entries
- *	will be created by the tty core in sysfs when tty_register_driver() is
- *	called.  This is to be used by drivers that have tty devices that can
- *	appear and disappear while the main tty driver is registered with the
- *	tty core.
- *
- * TTY_DRIVER_DEVPTS_MEM
- *	Don't use the standard arrays (&tty_driver.ttys and
- *	&tty_driver.termios), instead use dynamic memory keyed through the
- *	devpts filesystem. This is only applicable to the PTY driver.
- *
- * TTY_DRIVER_HARDWARE_BREAK
- *	Hardware handles break signals. Pass the requested timeout to the
- *	&tty_operations.break_ctl instead of using a simple on/off interface.
- *
- * TTY_DRIVER_DYNAMIC_ALLOC
- *	Do not allocate structures which are needed per line for this driver
- *	(&tty_driver.ports) as it would waste memory. The driver will take
- *	care. This is only applicable to the PTY driver.
- *
- * TTY_DRIVER_UNNUMBERED_NODE
- *	Do not create numbered ``/dev`` nodes. For example, create
- *	``/dev/ttyprintk`` and not ``/dev/ttyprintk0``. Applicable only when a
- *	driver for a single tty device is being allocated.
- */
-#define TTY_DRIVER_INSTALLED		0x0001
-#define TTY_DRIVER_RESET_TERMIOS	0x0002
-#define TTY_DRIVER_REAL_RAW		0x0004
-#define TTY_DRIVER_DYNAMIC_DEV		0x0008
-#define TTY_DRIVER_DEVPTS_MEM		0x0010
-#define TTY_DRIVER_HARDWARE_BREAK	0x0020
-#define TTY_DRIVER_DYNAMIC_ALLOC	0x0040
-#define TTY_DRIVER_UNNUMBERED_NODE	0x0080
-
-/* tty driver types */
-#define TTY_DRIVER_TYPE_SYSTEM		0x0001
-#define TTY_DRIVER_TYPE_CONSOLE		0x0002
-#define TTY_DRIVER_TYPE_SERIAL		0x0003
-#define TTY_DRIVER_TYPE_PTY		0x0004
-#define TTY_DRIVER_TYPE_SCC		0x0005	/* scc driver */
-#define TTY_DRIVER_TYPE_SYSCONS		0x0006
-
-/* system subtypes (magic, used by tty_io.c) */
-#define SYSTEM_TYPE_TTY			0x0001
-#define SYSTEM_TYPE_CONSOLE		0x0002
-#define SYSTEM_TYPE_SYSCONS		0x0003
-#define SYSTEM_TYPE_SYSPTMX		0x0004
-
-/* pty subtypes (magic, used by tty_io.c) */
-#define PTY_TYPE_MASTER			0x0001
-#define PTY_TYPE_SLAVE			0x0002
-
-/* serial subtype definitions */
-#define SERIAL_TYPE_NORMAL	1
-
 int tty_register_driver(struct tty_driver *driver);
 void tty_unregister_driver(struct tty_driver *driver);
 struct device *tty_register_device(struct tty_driver *driver, unsigned index,

include/linux/tty_ldisc.h

@@ -39,7 +39,6 @@ do {								\
 int ldsem_down_read(struct ld_semaphore *sem, long timeout);
 int ldsem_down_read_trylock(struct ld_semaphore *sem);
 int ldsem_down_write(struct ld_semaphore *sem, long timeout);
-int ldsem_down_write_trylock(struct ld_semaphore *sem);
 void ldsem_up_read(struct ld_semaphore *sem);
 void ldsem_up_write(struct ld_semaphore *sem);
 

kernel/debug/debug_core.c

@@ -837,10 +837,6 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
 {
 	struct kgdb_state kgdb_var;
 	struct kgdb_state *ks = &kgdb_var;
-	int ret = 0;
-
-	if (arch_kgdb_ops.enable_nmi)
-		arch_kgdb_ops.enable_nmi(0);
 	/*
 	 * Avoid entering the debugger if we were triggered due to an oops
 	 * but panic_timeout indicates the system should automatically
@@ -858,15 +854,11 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
 	ks->linux_regs		= regs;
 
 	if (kgdb_reenter_check(ks))
-		goto out; /* Ouch, double exception ! */
+		return 0; /* Ouch, double exception ! */
 	if (kgdb_info[ks->cpu].enter_kgdb != 0)
-		goto out;
+		return 0;
 
-	ret = kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
+	return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
-out:
-	if (arch_kgdb_ops.enable_nmi)
-		arch_kgdb_ops.enable_nmi(1);
-	return ret;
 }
 NOKPROBE_SYMBOL(kgdb_handle_exception);
 

kernel/debug/kdb/kdb_main.c

@@ -25,7 +25,6 @@
 #include <linux/smp.h>
 #include <linux/utsname.h>
 #include <linux/vmalloc.h>
-#include <linux/atomic.h>
 #include <linux/moduleparam.h>
 #include <linux/mm.h>
 #include <linux/init.h>
@@ -2087,32 +2086,6 @@ static int kdb_dmesg(int argc, const char **argv)
 	return 0;
 }
 #endif /* CONFIG_PRINTK */
-
-/* Make sure we balance enable/disable calls, must disable first. */
-static atomic_t kdb_nmi_disabled;
-
-static int kdb_disable_nmi(int argc, const char *argv[])
-{
-	if (atomic_read(&kdb_nmi_disabled))
-		return 0;
-	atomic_set(&kdb_nmi_disabled, 1);
-	arch_kgdb_ops.enable_nmi(0);
-	return 0;
-}
-
-static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
-{
-	if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
-		return -EINVAL;
-	arch_kgdb_ops.enable_nmi(1);
-	return 0;
-}
-
-static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
-	.set = kdb_param_enable_nmi,
-};
-module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
-
 /*
  * kdb_cpu - This function implements the 'cpu' command.
  *	cpu	[<cpunum>]
@@ -2804,20 +2777,10 @@ static kdbtab_t maintab[] = {
 	},
 };
 
-static kdbtab_t nmicmd = {
-	.name = "disable_nmi",
-	.func = kdb_disable_nmi,
-	.usage = "",
-	.help = "Disable NMI entry to KDB",
-	.flags = KDB_ENABLE_ALWAYS_SAFE,
-};
-
 /* Initialize the kdb command table. */
 static void __init kdb_inittab(void)
 {
 	kdb_register_table(maintab, ARRAY_SIZE(maintab));
-	if (arch_kgdb_ops.enable_nmi)
-		kdb_register_table(&nmicmd, 1);
 }
 
 /* Execute any commands defined in kdb_cmds.  */