watchdog: rzg2l_wdt: Add set_timeout callback

This patch adds support for set_timeout callback.

Once WDT is started, the WDT cycle setting register(WDTSET) can be updated
only after issuing a module reset. Otherwise, it will ignore the writes
and will hold the previous value. This patch updates the WDTSET register
if it is active.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220225175320.11041-8-biju.das.jz@bp.renesas.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 4e7107655cc226d1be00d0985327bf25d1c43c8f..6eea0ee4af49eae9b9a98c2c9a8878118bf89214 100644 (file)
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -115,6 +115,25 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
        return 0;
 }
 
+static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout)
+{
+       struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+       wdev->timeout = timeout;
+
+       /*
+        * If the watchdog is active, reset the module for updating the WDTSET
+        * register so that it is updated with new timeout values.
+        */
+       if (watchdog_active(wdev)) {
+               pm_runtime_put(wdev->parent);
+               reset_control_reset(priv->rstc);
+               rzg2l_wdt_start(wdev);
+       }
+
+       return 0;
+}
+
 static int rzg2l_wdt_restart(struct watchdog_device *wdev,
                             unsigned long action, void *data)
 {
@@ -151,6 +170,7 @@ static const struct watchdog_ops rzg2l_wdt_ops = {
        .start = rzg2l_wdt_start,
        .stop = rzg2l_wdt_stop,
        .ping = rzg2l_wdt_ping,
+       .set_timeout = rzg2l_wdt_set_timeout,
        .restart = rzg2l_wdt_restart,
 };