watchdog: renesas_wdt: Add restart handler

On iWave's boards iwg20d and iwg22d the only way to reboot the system is
by means of the watchdog.
This patch adds a restart handler to rwdt_ops, and also makes sure we
keep its priority to the lowest level, in order to not override other
more effective handlers.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
index 0dede5beb3f1..6b8c6ddfe30b 100644
--- a/drivers/watchdog/renesas_wdt.c
+++ b/drivers/watchdog/renesas_wdt.c
@@ -110,6 +110,16 @@ static unsigned int rwdt_get_timeleft(struct watchdog_device *wdev)
         return DIV_BY_CLKS_PER_SEC(priv, 65536 - val);
 }
 
+static int rwdt_restart(struct watchdog_device *wdev, unsigned long action,
+                        void *data)
+{
+        struct rwdt_priv *priv = watchdog_get_drvdata(wdev);
+
+        rwdt_start(wdev);
+        rwdt_write(priv, 0xffff, RWTCNT);
+        return 0;
+}
+
 static const struct watchdog_info rwdt_ident = {
         .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
         .identity = "Renesas WDT Watchdog",
@@ -121,6 +131,7 @@ static const struct watchdog_ops rwdt_ops = {
         .stop = rwdt_stop,
         .ping = rwdt_init_timeout,
         .get_timeleft = rwdt_get_timeleft,
+        .restart = rwdt_restart,
 };
 
 #if defined(CONFIG_ARCH_RCAR_GEN2) && defined(CONFIG_SMP)
@@ -220,6 +231,7 @@ static int rwdt_probe(struct platform_device *pdev)
         platform_set_drvdata(pdev, priv);
         watchdog_set_drvdata(&priv->wdev, priv);
         watchdog_set_nowayout(&priv->wdev, nowayout);
+        watchdog_set_restart_priority(&priv->wdev, 0);
 
         /* This overrides the default timeout only if DT configuration was found */
         ret = watchdog_init_timeout(&priv->wdev, 0, &pdev->dev);