diff mbox series

[v2,3/4] watchdog: rzg2l_wdt: Add set_timeout callback

Message ID 20211213152658.26225-3-biju.das.jz@bp.renesas.com
State Superseded
Headers show
Series [v2,1/4] watchdog: rzg2l_wdt: Fix 32bit overflow issue | expand

Commit Message

Biju Das Dec. 13, 2021, 3:26 p.m. UTC
Once watchdog is started, WDT cycle setting register(WDTSET) cannot be
changed. However we can reconfigure the new value for WDSET, after a
module reset. Otherwise it will ignore the writes and will hold the
previous value instead of the updated one.

This patch add support for set_timeout callback by doing module
reset, which allows us to update WDTSET register. Based on the
watchdog timer state, it may restart WDT with the modified values.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
V1->V2:
 * Updated commit description
 * Removed stop/start and started using reset() instead.
 * After reset, Start WDT based on watchdog timer state.
---
 drivers/watchdog/rzg2l_wdt.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
diff mbox series

Patch

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 0e62d7be153c..d1b5cb70d56c 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -110,6 +110,33 @@  static int rzg2l_wdt_stop(struct watchdog_device *wdev)
 	return reset_control_reset(priv->rstc);
 }
 
+static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout)
+{
+	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	int ret;
+
+	wdev->timeout = timeout;
+
+	/*
+	 * We need to reset the module for updating WDTSET register
+	 * If watchdog is active, then decrement the PM counter to make
+	 * it balanced, after reset operation.
+	 */
+	if (watchdog_active(wdev))
+		pm_runtime_put(wdev->parent);
+
+	/* Reset the module for updating WDTSET register */
+	ret = reset_control_reset(priv->rstc);
+	if (watchdog_active(wdev)) {
+		if (ret)
+			pm_runtime_get_sync(wdev->parent);
+		else
+			rzg2l_wdt_start(wdev);
+	}
+
+	return ret;
+}
+
 static int rzg2l_wdt_restart(struct watchdog_device *wdev,
 			     unsigned long action, void *data)
 {
@@ -153,6 +180,7 @@  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,
 };