MLK-11360-01 crypto: caam_snvs: add snvs clock management

caam_snvs driver involves snvs HP registers access that needs to
enable snvs clock source. The patch add the clock management.

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Dan Douglass <dan.douglass@freescale.com>
(Vipul: Fixed merge conflicts)
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>

Documentation/devicetree/bindings/crypto/fsl-sec4.txt

@@ -456,18 +456,14 @@ Secure Non-Volatile Storage (SNVS) Low Power (LP) RTC Node
 	value type: <u32>
 	Definition: LP register offset. default it is 0x34.
 
-   - clocks
-      Usage: optional, required if SNVS LP RTC requires explicit
-          enablement of clocks
-      Value type: <prop_encoded-array>
-      Definition:  a clock specifier describing the clock required for
-          enabling and disabling SNVS LP RTC.
-
-   - clock-names
-      Usage: optional, required if SNVS LP RTC requires explicit
-          enablement of clocks
-      Value type: <string>
-      Definition: clock name string should be "snvs-rtc".
+  - clocks
+      Usage: optional
+      Value type: <prop-encoded-array>
+      Definition: A standard property.  Specifies the source clock for
+	  snvs register access. If i.MX clk driver defines the clock node,
+	  it needs user to specify the clocks in device tree for all modules
+	  with snvs LP/HP registers access. The modules involved snvs LP/HP
+	  registers access are snvs-power key, snvs-rtc, and caam.
 
 EXAMPLE
 	sec_mon_rtc_lp@1 {

drivers/crypto/caam/secvio.c

@@ -51,12 +51,15 @@ static irqreturn_t snvs_secvio_interrupt(int irq, void *snvsdev)
 	struct device *dev = snvsdev;
 	struct snvs_secvio_drv_private *svpriv = dev_get_drvdata(dev);
 
+	clk_enable(svpriv->clk);
 	/* Check the HP secvio status register */
 	svpriv->irqcause = rd_reg32(&svpriv->svregs->hp.secvio_status) &
 				    HP_SECVIOST_SECVIOMASK;
 
-	if (!svpriv->irqcause)
+	if (!svpriv->irqcause) {
+		clk_disable(svpriv->clk);
 		return IRQ_NONE;
+	}
 
 	/* Now ACK cause */
 	clrsetbits_32(&svpriv->svregs->hp.secvio_status, 0, svpriv->irqcause);
@@ -66,6 +69,8 @@ static irqreturn_t snvs_secvio_interrupt(int irq, void *snvsdev)
 	tasklet_schedule(&svpriv->irqtask[smp_processor_id()]);
 	preempt_enable();
 
+	clk_disable(svpriv->clk);
+
 	return IRQ_HANDLED;
 }
 
@@ -176,6 +181,7 @@ static int snvs_secvio_remove(struct platform_device *pdev)
 	svdev = &pdev->dev;
 	svpriv = dev_get_drvdata(svdev);
 
+	clk_enable(svpriv->clk);
 	/* Set all sources to nonfatal */
 	wr_reg32(&svpriv->svregs->hp.secvio_intcfg, 0);
 
@@ -183,6 +189,7 @@ static int snvs_secvio_remove(struct platform_device *pdev)
 	for_each_possible_cpu(i)
 		tasklet_kill(&svpriv->irqtask[i]);
 
+	clk_disable_unprepare(svpriv->clk);
 	free_irq(svpriv->irq, svdev);
 	iounmap(svpriv->svregs);
 	kfree(svpriv);
@@ -227,6 +234,12 @@ static int snvs_secvio_probe(struct platform_device *pdev)
 	}
 	svpriv->svregs = (struct snvs_full __force *)snvsregs;
 
+	svpriv->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(svpriv->clk)) {
+		dev_err(&pdev->dev, "can't get snvs clock\n");
+		svpriv->clk = NULL;
+	}
+
 	 /* Device data set up. Now init interrupt source descriptions */
 	for (i = 0; i < MAX_SECVIO_SOURCES; i++) {
 		svpriv->intsrc[i].intname = violation_src_name[i];
@@ -248,6 +261,7 @@ static int snvs_secvio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	clk_prepare_enable(svpriv->clk);
 	/*
 	 * Configure all sources as fatal violations except LP section,
 	 * source #5 (typically used as an external tamper detect), and
@@ -263,6 +277,8 @@ static int snvs_secvio_probe(struct platform_device *pdev)
 	dev_info(svdev, "violation handlers armed - %s state\n",
 		 snvs_ssm_state_name[hpstate]);
 
+	clk_disable(svpriv->clk);
+
 	return 0;
 }
 

drivers/crypto/caam/secvio.h

@@ -55,6 +55,7 @@ struct snvs_secvio_drv_private {
 	spinlock_t svlock ____cacheline_aligned;
 	struct tasklet_struct irqtask[NR_CPUS];
 	struct snvs_full __iomem *svregs;	/* both HP and LP domains */
+	struct clk *clk;
 	int irq;
 	u32 irqcause; /* stashed cause of violation interrupt */