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lf-6.6.y
linux-imx/drivers/iio/adc/adi-axi-adc.c
Nuno Sa 955c824d54 iio: adc: axi-adc: make sure AXI clock is enabled 
commit 80721776c5 upstream.

We can only access the IP core registers if the bus clock is enabled. As
such we need to get and enable it and not rely on anyone else to do it.

Note this clock is a very fundamental one that is typically enabled
pretty early during boot. Independently of that, we should really rely on
it to be enabled.

Fixes: ef04070692 ("iio: adc: adi-axi-adc: add support for AXI ADC IP core")
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240426-ad9467-new-features-v2-4-6361fc3ba1cc@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-21 14:38:42 +02:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Analog Devices Generic AXI ADC IP core
* Link: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
*
* Copyright 2012-2020 Analog Devices Inc.
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/fpga/adi-axi-common.h>
#include <linux/iio/backend.h>
#include <linux/iio/buffer-dmaengine.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
/*
* Register definitions:
* https://wiki.analog.com/resources/fpga/docs/axi_adc_ip#register_map
*/
/* ADC controls */
#define ADI_AXI_REG_RSTN 0x0040
#define ADI_AXI_REG_RSTN_CE_N BIT(2)
#define ADI_AXI_REG_RSTN_MMCM_RSTN BIT(1)
#define ADI_AXI_REG_RSTN_RSTN BIT(0)
/* ADC Channel controls */
#define ADI_AXI_REG_CHAN_CTRL(c) (0x0400 + (c) * 0x40)
#define ADI_AXI_REG_CHAN_CTRL_LB_OWR BIT(11)
#define ADI_AXI_REG_CHAN_CTRL_PN_SEL_OWR BIT(10)
#define ADI_AXI_REG_CHAN_CTRL_IQCOR_EN BIT(9)
#define ADI_AXI_REG_CHAN_CTRL_DCFILT_EN BIT(8)
#define ADI_AXI_REG_CHAN_CTRL_FMT_MASK GENMASK(6, 4)
#define ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT BIT(6)
#define ADI_AXI_REG_CHAN_CTRL_FMT_TYPE BIT(5)
#define ADI_AXI_REG_CHAN_CTRL_FMT_EN BIT(4)
#define ADI_AXI_REG_CHAN_CTRL_PN_TYPE_OWR BIT(1)
#define ADI_AXI_REG_CHAN_CTRL_ENABLE BIT(0)
#define ADI_AXI_REG_CHAN_CTRL_DEFAULTS \
(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT | \
ADI_AXI_REG_CHAN_CTRL_FMT_EN | \
ADI_AXI_REG_CHAN_CTRL_ENABLE)
struct adi_axi_adc_state {
struct regmap *regmap;
struct device *dev;
};
static int axi_adc_enable(struct iio_backend *back)
{
struct adi_axi_adc_state *st = iio_backend_get_priv(back);
int ret;
ret = regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
ADI_AXI_REG_RSTN_MMCM_RSTN);
if (ret)
return ret;
fsleep(10000);
return regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
}
static void axi_adc_disable(struct iio_backend *back)
{
struct adi_axi_adc_state *st = iio_backend_get_priv(back);
regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
}
static int axi_adc_data_format_set(struct iio_backend *back, unsigned int chan,
const struct iio_backend_data_fmt *data)
{
struct adi_axi_adc_state *st = iio_backend_get_priv(back);
u32 val;
if (!data->enable)
return regmap_clear_bits(st->regmap,
ADI_AXI_REG_CHAN_CTRL(chan),
ADI_AXI_REG_CHAN_CTRL_FMT_EN);
val = FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_EN, true);
if (data->sign_extend)
val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT, true);
if (data->type == IIO_BACKEND_OFFSET_BINARY)
val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_TYPE, true);
return regmap_update_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
ADI_AXI_REG_CHAN_CTRL_FMT_MASK, val);
}
static int axi_adc_chan_enable(struct iio_backend *back, unsigned int chan)
{
struct adi_axi_adc_state *st = iio_backend_get_priv(back);
return regmap_set_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
ADI_AXI_REG_CHAN_CTRL_ENABLE);
}
static int axi_adc_chan_disable(struct iio_backend *back, unsigned int chan)
{
struct adi_axi_adc_state *st = iio_backend_get_priv(back);
return regmap_clear_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
ADI_AXI_REG_CHAN_CTRL_ENABLE);
}
static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
struct iio_dev *indio_dev)
{
struct adi_axi_adc_state *st = iio_backend_get_priv(back);
struct iio_buffer *buffer;
const char *dma_name;
int ret;
if (device_property_read_string(st->dev, "dma-names", &dma_name))
dma_name = "rx";
buffer = iio_dmaengine_buffer_alloc(st->dev, dma_name);
if (IS_ERR(buffer)) {
dev_err(st->dev, "Could not get DMA buffer, %ld\n",
PTR_ERR(buffer));
return ERR_CAST(buffer);
}
indio_dev->modes |= INDIO_BUFFER_HARDWARE;
ret = iio_device_attach_buffer(indio_dev, buffer);
if (ret)
return ERR_PTR(ret);
return buffer;
}
static void axi_adc_free_buffer(struct iio_backend *back,
struct iio_buffer *buffer)
{
iio_dmaengine_buffer_free(buffer);
}
static const struct regmap_config axi_adc_regmap_config = {
.val_bits = 32,
.reg_bits = 32,
.reg_stride = 4,
.max_register = 0x0800,
};
static const struct iio_backend_ops adi_axi_adc_generic = {
.enable = axi_adc_enable,
.disable = axi_adc_disable,
.data_format_set = axi_adc_data_format_set,
.chan_enable = axi_adc_chan_enable,
.chan_disable = axi_adc_chan_disable,
.request_buffer = axi_adc_request_buffer,
.free_buffer = axi_adc_free_buffer,
};
static int adi_axi_adc_probe(struct platform_device *pdev)
{
const unsigned int *expected_ver;
struct adi_axi_adc_state *st;
void __iomem *base;
unsigned int ver;
struct clk *clk;
int ret;
st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
if (!st)
return -ENOMEM;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
st->dev = &pdev->dev;
st->regmap = devm_regmap_init_mmio(&pdev->dev, base,
&axi_adc_regmap_config);
if (IS_ERR(st->regmap))
return PTR_ERR(st->regmap);
expected_ver = device_get_match_data(&pdev->dev);
if (!expected_ver)
return -ENODEV;
clk = devm_clk_get_enabled(&pdev->dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
/*
* Force disable the core. Up to the frontend to enable us. And we can
* still read/write registers...
*/
ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
if (ret)
return ret;
ret = regmap_read(st->regmap, ADI_AXI_REG_VERSION, &ver);
if (ret)
return ret;
if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
dev_err(&pdev->dev,
"Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
ADI_AXI_PCORE_VER_MAJOR(*expected_ver),
ADI_AXI_PCORE_VER_MINOR(*expected_ver),
ADI_AXI_PCORE_VER_PATCH(*expected_ver),
ADI_AXI_PCORE_VER_MAJOR(ver),
ADI_AXI_PCORE_VER_MINOR(ver),
ADI_AXI_PCORE_VER_PATCH(ver));
return -ENODEV;
}
ret = devm_iio_backend_register(&pdev->dev, &adi_axi_adc_generic, st);
if (ret)
return ret;
dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%c) probed\n",
ADI_AXI_PCORE_VER_MAJOR(ver),
ADI_AXI_PCORE_VER_MINOR(ver),
ADI_AXI_PCORE_VER_PATCH(ver));
return 0;
}
static unsigned int adi_axi_adc_10_0_a_info = ADI_AXI_PCORE_VER(10, 0, 'a');
/* Match table for of_platform binding */
static const struct of_device_id adi_axi_adc_of_match[] = {
{ .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
{ /* end of list */ }
};
MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
static struct platform_driver adi_axi_adc_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = adi_axi_adc_of_match,
},
.probe = adi_axi_adc_probe,
};
module_platform_driver(adi_axi_adc_driver);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices Generic AXI ADC IP core driver");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(IIO_DMAENGINE_BUFFER);
MODULE_IMPORT_NS(IIO_BACKEND);
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