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>

diff --git a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
index 6d63782..c6ae9c9 100644 (file)
--- a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
@@ -7,6 +7,8 @@ Required properties:
 - reg                  : Physical base address and size
 
 Optional properties:
+- clocks               : Input clock specifier. Refer to common clock
+                         bindings.
 - clock-frequency      : Frequency of clock in Hz
 - xlnx,wdt-enable-once : 0 - Watchdog can be restarted
                          1 - Watchdog can be enabled just once
@@ -17,6 +19,7 @@ Example:
 axi-timebase-wdt@40100000 {
        clock-frequency = <50000000>;
        compatible = "xlnx,xps-timebase-wdt-1.00.a";
+       clocks = <&clkc 15>;
        reg = <0x40100000 0x10000>;
        xlnx,wdt-enable-once = <0x0>;
        xlnx,wdt-interval = <0x1b>;

diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
index b2e1b4c..fae7fe9 100644 (file)
--- 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;
 }