On 01/31/2018 10:24 AM, Fabrizio Castro wrote:
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 a medium level, in order to not override other more
effective handlers.

Signed-off-by: Fabrizio Castro <fabrizio.cas...@bp.renesas.com>
Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasunda...@bp.renesas.com>

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

---
v3->v4:
* New patch spawn out from patch 12/16. The restart handler on Gen3 is
   controversial, hopefully this patch will help finalizing the discussion.

  drivers/watchdog/renesas_wdt.c | 20 ++++++++++++++++++++
  1 file changed, 20 insertions(+)

diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
index 0a1a402..6d1c4b9 100644
--- a/drivers/watchdog/renesas_wdt.c
+++ b/drivers/watchdog/renesas_wdt.c
@@ -107,6 +107,24 @@ 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);
+
+       pm_runtime_get_sync(wdev->parent);
+
+       rwdt_write(priv, 0x00, RWTCSRB);
+       rwdt_write(priv, 0x00, RWTCSRA);
+       rwdt_write(priv, 0xffff, RWTCNT);
+
+       while (readb_relaxed(priv->base + RWTCSRA) & RWTCSRA_WRFLG)
+               cpu_relax();
+
+       rwdt_write(priv, 0x80, RWTCSRA);
+       return 0;
+}
+
  static const struct watchdog_info rwdt_ident = {
        .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
        .identity = "Renesas WDT Watchdog",
@@ -118,6 +136,7 @@ static const struct watchdog_ops rwdt_ops = {
        .stop = rwdt_stop,
        .ping = rwdt_init_timeout,
        .get_timeleft = rwdt_get_timeleft,
+       .restart = rwdt_restart,
  };
static int rwdt_probe(struct platform_device *pdev)
@@ -176,6 +195,7 @@ 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, 128);
/* This overrides the default timeout only if DT configuration was found */
        ret = watchdog_init_timeout(&priv->wdev, 0, &pdev->dev);


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