[PATCH 1/2] watchdog: of_xilinx_wdt: Add support for reading freq via CCF

[PATCH 1/2] watchdog: of_xilinx_wdt: Add support for reading freq via CCF

[Michal Simek]

From: Maulik Jodhani <maulik.jodhani@xilinx.com>

Improve CLK handling in the code to read freq via CCF.
Also disable CLK asap and add clk handling code to start and stop.

Signed-off-by: Maulik Jodhani <maulik.jodhani@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

 drivers/watchdog/of_xilinx_wdt.c | 45 ++++++++++++++++++++++++++++------------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
index fae7fe929ea3..41edeb93a327 100644
--- a/drivers/watchdog/of_xilinx_wdt.c
+++ b/drivers/watchdog/of_xilinx_wdt.c
@@ -51,9 +51,16 @@ struct xwdt_device {
 
 static int xilinx_wdt_start(struct watchdog_device *wdd)
 {
+	int ret;
 	u32 control_status_reg;
 	struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
 
+	ret = clk_enable(xdev->clk);
+	if (ret) {
+		dev_err(wdd->parent, "Failed to enable clock\n");
+		return ret;
+	}
+
 	spin_lock(&xdev->spinlock);
 
 	/* Clean previous status and enable the watchdog timer */
@@ -85,6 +92,9 @@ static int xilinx_wdt_stop(struct watchdog_device *wdd)
 	iowrite32(0, xdev->base + XWT_TWCSR1_OFFSET);
 
 	spin_unlock(&xdev->spinlock);
+
+	clk_disable(xdev->clk);
+
 	pr_info("Stopped!\n");
 
 	return 0;
@@ -167,11 +177,6 @@ static int xwdt_probe(struct platform_device *pdev)
 	if (IS_ERR(xdev->base))
 		return PTR_ERR(xdev->base);
 
-	rc = of_property_read_u32(pdev->dev.of_node, "clock-frequency", &pfreq);
-	if (rc)
-		dev_warn(&pdev->dev,
-			 "The watchdog clock frequency cannot be obtained\n");
-
 	rc = of_property_read_u32(pdev->dev.of_node, "xlnx,wdt-interval",
 				  &xdev->wdt_interval);
 	if (rc)
@@ -186,6 +191,26 @@ static int xwdt_probe(struct platform_device *pdev)
 
 	watchdog_set_nowayout(xilinx_wdt_wdd, enable_once);
 
+	xdev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(xdev->clk)) {
+		if (PTR_ERR(xdev->clk) != -ENOENT)
+			return PTR_ERR(xdev->clk);
+
+		/*
+		 * Clock framework support is optional, continue on
+		 * anyways if we don't find a matching clock.
+		 */
+		xdev->clk = NULL;
+
+		rc = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+					  &pfreq);
+		if (rc)
+			dev_warn(&pdev->dev,
+				 "The watchdog clock freq cannot be obtained\n");
+	} else {
+		pfreq = clk_get_rate(xdev->clk);
+	}
+
 	/*
 	 * Twice of the 2^wdt_interval / freq  because the first wdt overflow is
 	 * ignored (interrupt), reset is only generated at second wdt overflow
@@ -197,14 +222,6 @@ static int xwdt_probe(struct platform_device *pdev)
 	spin_lock_init(&xdev->spinlock);
 	watchdog_set_drvdata(xilinx_wdt_wdd, xdev);
 
-	xdev->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(xdev->clk)) {
-		if (PTR_ERR(xdev->clk) == -ENOENT)
-			xdev->clk = NULL;
-		else
-			return PTR_ERR(xdev->clk);
-	}
-
 	rc = clk_prepare_enable(xdev->clk);
 	if (rc) {
 		dev_err(&pdev->dev, "unable to enable clock\n");
@@ -223,6 +240,8 @@ static int xwdt_probe(struct platform_device *pdev)
 		goto err_clk_disable;
 	}
 
+	clk_disable(xdev->clk);
+
 	dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
 		 xdev->base, xilinx_wdt_wdd->timeout);
 
-- 
1.9.1

[PATCH 2/2] watchdog: of_xilinx_wdt: Add suspend/resume support

[Michal Simek]

Add suspend/resume support to driver.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

 drivers/watchdog/of_xilinx_wdt.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
index 41edeb93a327..1cf286945b7a 100644
--- a/drivers/watchdog/of_xilinx_wdt.c
+++ b/drivers/watchdog/of_xilinx_wdt.c
@@ -264,6 +264,43 @@ static int xwdt_remove(struct platform_device *pdev)
 	return 0;
 }
 
+/**
+ * xwdt_suspend - Suspend the device.
+ *
+ * @dev: handle to the device structure.
+ * Return: 0 always.
+ */
+static int __maybe_unused xwdt_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct xwdt_device *xdev = platform_get_drvdata(pdev);
+
+	if (watchdog_active(&xdev->xilinx_wdt_wdd))
+		xilinx_wdt_stop(&xdev->xilinx_wdt_wdd);
+
+	return 0;
+}
+
+/**
+ * xwdt_resume - Resume the device.
+ *
+ * @dev: handle to the device structure.
+ * Return: 0 on success, errno otherwise.
+ */
+static int __maybe_unused xwdt_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct xwdt_device *xdev = platform_get_drvdata(pdev);
+	int ret = 0;
+
+	if (watchdog_active(&xdev->xilinx_wdt_wdd))
+		ret = xilinx_wdt_start(&xdev->xilinx_wdt_wdd);
+
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(xwdt_pm_ops, xwdt_suspend, xwdt_resume);
+
 /* Match table for of_platform binding */
 static const struct of_device_id xwdt_of_match[] = {
 	{ .compatible = "xlnx,xps-timebase-wdt-1.00.a", },
@@ -278,6 +315,7 @@ static int xwdt_remove(struct platform_device *pdev)
 	.driver = {
 		.name  = WATCHDOG_NAME,
 		.of_match_table = xwdt_of_match,
+		.pm = &xwdt_pm_ops,
 	},
 };
 
-- 
1.9.1

Re: [1/2] watchdog: of_xilinx_wdt: Add support for reading freq via CCF

[Guenter Roeck]

On Mon, Aug 07, 2017 at 01:24:22PM +0200, Michal Simek wrote:
> From: Maulik Jodhani <maulik.jodhani@xilinx.com>
> 
> Improve CLK handling in the code to read freq via CCF.
> Also disable CLK asap and add clk handling code to start and stop.
> 
> Signed-off-by: Maulik Jodhani <maulik.jodhani@xilinx.com>
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
>  drivers/watchdog/of_xilinx_wdt.c | 45 ++++++++++++++++++++++++++++------------
>  1 file changed, 32 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
> index fae7fe929ea3..41edeb93a327 100644
> --- a/drivers/watchdog/of_xilinx_wdt.c
> +++ b/drivers/watchdog/of_xilinx_wdt.c
> @@ -51,9 +51,16 @@ struct xwdt_device {
>  
>  static int xilinx_wdt_start(struct watchdog_device *wdd)
>  {
> +	int ret;
>  	u32 control_status_reg;
>  	struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
>  
> +	ret = clk_enable(xdev->clk);
> +	if (ret) {
> +		dev_err(wdd->parent, "Failed to enable clock\n");
> +		return ret;
> +	}
> +
>  	spin_lock(&xdev->spinlock);
>  
>  	/* Clean previous status and enable the watchdog timer */
> @@ -85,6 +92,9 @@ static int xilinx_wdt_stop(struct watchdog_device *wdd)
>  	iowrite32(0, xdev->base + XWT_TWCSR1_OFFSET);
>  
>  	spin_unlock(&xdev->spinlock);
> +
> +	clk_disable(xdev->clk);
> +
>  	pr_info("Stopped!\n");
>  
>  	return 0;
> @@ -167,11 +177,6 @@ static int xwdt_probe(struct platform_device *pdev)
>  	if (IS_ERR(xdev->base))
>  		return PTR_ERR(xdev->base);
>  
> -	rc = of_property_read_u32(pdev->dev.of_node, "clock-frequency", &pfreq);
> -	if (rc)
> -		dev_warn(&pdev->dev,
> -			 "The watchdog clock frequency cannot be obtained\n");
> -
>  	rc = of_property_read_u32(pdev->dev.of_node, "xlnx,wdt-interval",
>  				  &xdev->wdt_interval);
>  	if (rc)
> @@ -186,6 +191,26 @@ static int xwdt_probe(struct platform_device *pdev)
>  
>  	watchdog_set_nowayout(xilinx_wdt_wdd, enable_once);
>  
> +	xdev->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(xdev->clk)) {
> +		if (PTR_ERR(xdev->clk) != -ENOENT)
> +			return PTR_ERR(xdev->clk);
> +
> +		/*
> +		 * Clock framework support is optional, continue on
> +		 * anyways if we don't find a matching clock.
> +		 */
> +		xdev->clk = NULL;
> +
> +		rc = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
> +					  &pfreq);
> +		if (rc)
> +			dev_warn(&pdev->dev,
> +				 "The watchdog clock freq cannot be obtained\n");
> +	} else {
> +		pfreq = clk_get_rate(xdev->clk);
> +	}
> +
>  	/*
>  	 * Twice of the 2^wdt_interval / freq  because the first wdt overflow is
>  	 * ignored (interrupt), reset is only generated at second wdt overflow
> @@ -197,14 +222,6 @@ static int xwdt_probe(struct platform_device *pdev)
>  	spin_lock_init(&xdev->spinlock);
>  	watchdog_set_drvdata(xilinx_wdt_wdd, xdev);
>  
> -	xdev->clk = devm_clk_get(&pdev->dev, NULL);
> -	if (IS_ERR(xdev->clk)) {
> -		if (PTR_ERR(xdev->clk) == -ENOENT)
> -			xdev->clk = NULL;
> -		else
> -			return PTR_ERR(xdev->clk);
> -	}
> -
>  	rc = clk_prepare_enable(xdev->clk);
>  	if (rc) {
>  		dev_err(&pdev->dev, "unable to enable clock\n");
> @@ -223,6 +240,8 @@ static int xwdt_probe(struct platform_device *pdev)
>  		goto err_clk_disable;
>  	}
>  
> +	clk_disable(xdev->clk);
> +
>  	dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
>  		 xdev->base, xilinx_wdt_wdd->timeout);
>  

Re: [2/2] watchdog: of_xilinx_wdt: Add suspend/resume support

[Guenter Roeck]

On Mon, Aug 07, 2017 at 01:24:23PM +0200, Michal Simek wrote:
> Add suspend/resume support to driver.
> 
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
>  drivers/watchdog/of_xilinx_wdt.c | 38 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
> index 41edeb93a327..1cf286945b7a 100644
> --- a/drivers/watchdog/of_xilinx_wdt.c
> +++ b/drivers/watchdog/of_xilinx_wdt.c
> @@ -264,6 +264,43 @@ static int xwdt_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +/**
> + * xwdt_suspend - Suspend the device.
> + *
> + * @dev: handle to the device structure.
> + * Return: 0 always.
> + */
> +static int __maybe_unused xwdt_suspend(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct xwdt_device *xdev = platform_get_drvdata(pdev);
> +
> +	if (watchdog_active(&xdev->xilinx_wdt_wdd))
> +		xilinx_wdt_stop(&xdev->xilinx_wdt_wdd);
> +
> +	return 0;
> +}
> +
> +/**
> + * xwdt_resume - Resume the device.
> + *
> + * @dev: handle to the device structure.
> + * Return: 0 on success, errno otherwise.
> + */
> +static int __maybe_unused xwdt_resume(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct xwdt_device *xdev = platform_get_drvdata(pdev);
> +	int ret = 0;
> +
> +	if (watchdog_active(&xdev->xilinx_wdt_wdd))
> +		ret = xilinx_wdt_start(&xdev->xilinx_wdt_wdd);
> +
> +	return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(xwdt_pm_ops, xwdt_suspend, xwdt_resume);
> +
>  /* Match table for of_platform binding */
>  static const struct of_device_id xwdt_of_match[] = {
>  	{ .compatible = "xlnx,xps-timebase-wdt-1.00.a", },
> @@ -278,6 +315,7 @@ static int xwdt_remove(struct platform_device *pdev)
>  	.driver = {
>  		.name  = WATCHDOG_NAME,
>  		.of_match_table = xwdt_of_match,
> +		.pm = &xwdt_pm_ops,
>  	},
>  };
>