watchdog: xilinx: Add clock support

Add support for the clock. Currently we enable
at probe and relinquish at remove.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 23 insertions, 2 deletions

diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
index b2e1b4cbbdc1..fae7fe929ea3 100644
--- a/drivers/watchdog/of_xilinx_wdt.c
+++ b/drivers/watchdog/of_xilinx_wdt.c
@@ -10,6 +10,7 @@
  * 2 of the License, or (at your option) any later version.
  */
 
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/types.h>
@@ -45,6 +46,7 @@ struct xwdt_device {
 	u32 wdt_interval;
 	spinlock_t spinlock;
 	struct watchdog_device xilinx_wdt_wdd;
+	struct clk		*clk;
 };
 
 static int xilinx_wdt_start(struct watchdog_device *wdd)
@@ -195,16 +197,30 @@ 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");
+		return rc;
+	}
+
 	rc = xwdt_selftest(xdev);
 	if (rc == XWT_TIMER_FAILED) {
 		dev_err(&pdev->dev, "SelfTest routine error\n");
-		return rc;
+		goto err_clk_disable;
 	}
 
 	rc = watchdog_register_device(xilinx_wdt_wdd);
 	if (rc) {
 		dev_err(&pdev->dev, "Cannot register watchdog (err=%d)\n", rc);
-		return rc;
+		goto err_clk_disable;
 	}
 
 	dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
@@ -213,6 +229,10 @@ static int xwdt_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, xdev);
 
 	return 0;
+err_clk_disable:
+	clk_disable_unprepare(xdev->clk);
+
+	return rc;
 }
 
 static int xwdt_remove(struct platform_device *pdev)
@@ -220,6 +240,7 @@ static int xwdt_remove(struct platform_device *pdev)
 	struct xwdt_device *xdev = platform_get_drvdata(pdev);
 
 	watchdog_unregister_device(&xdev->xilinx_wdt_wdd);
+	clk_disable_unprepare(xdev->clk);
 
 	return 0;
 }