watchdog: imgpdc: Add reboot support

Register a restart handler that will restart the system by writing
to the watchdog's SOFT_RESET register.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Reviewed-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/watchdog/imgpdc_wdt.c b/drivers/watchdog/imgpdc_wdt.c
index ffeb1bf85252..28c10e292aa3 100644
--- a/drivers/watchdog/imgpdc_wdt.c
+++ b/drivers/watchdog/imgpdc_wdt.c
@@ -16,6 +16,7 @@
 #include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/reboot.h>
 #include <linux/slab.h>
 #include <linux/watchdog.h>
 
@@ -57,6 +58,7 @@ struct pdc_wdt_dev {
         struct clk *wdt_clk;
         struct clk *sys_clk;
         void __iomem *base;
+        struct notifier_block restart_handler;
 };
 
 static int pdc_wdt_keepalive(struct watchdog_device *wdt_dev)
@@ -136,6 +138,18 @@ static const struct watchdog_ops pdc_wdt_ops = {
         .set_timeout    = pdc_wdt_set_timeout,
 };
 
+static int pdc_wdt_restart(struct notifier_block *this, unsigned long mode,
+                           void *cmd)
+{
+        struct pdc_wdt_dev *wdt = container_of(this, struct pdc_wdt_dev,
+                                               restart_handler);
+
+        /* Assert SOFT_RESET */
+        writel(0x1, wdt->base + PDC_WDT_SOFT_RESET);
+
+        return NOTIFY_OK;
+}
+
 static int pdc_wdt_probe(struct platform_device *pdev)
 {
         int ret, val;
@@ -242,6 +256,13 @@ static int pdc_wdt_probe(struct platform_device *pdev)
         if (ret)
                 goto disable_wdt_clk;
 
+        pdc_wdt->restart_handler.notifier_call = pdc_wdt_restart;
+        pdc_wdt->restart_handler.priority = 128;
+        ret = register_restart_handler(&pdc_wdt->restart_handler);
+        if (ret)
+                dev_warn(&pdev->dev, "failed to register restart handler: %d\n",
+                         ret);
+
         return 0;
 
 disable_wdt_clk: