[PATCH v2 5.10.y-cip 11/12] watchdog: rzg2l_wdt: Use force reset for WDT reset

Biju Das

commit f43e6ddbd7d7b63b9e71927a1f50860f8d55f9cc upstream.

This patch uses the force reset(WDTRSTB) for triggering WDT reset for
restart callback. This method(ie, Generate Reset (WDTRSTB) Signal on
parity error)is faster compared to the overflow method for triggering
watchdog reset.

Overflow method:
reboot: Restarting system
Reboot failed -- System halted
NOTICE: BL2: v2.5(release):v2.5/rzg2l-1.00-27-gf48f1440c

Parity error method:
reboot: Restarting system
NOTICE: BL2: v2.5(release):v2.5/rzg2l-1.00-27-gf48f1440c

Signed-off-by: Biju Das <biju.das.jz@...>
Reviewed-by: Geert Uytterhoeven <geert+renesas@...>
Reviewed-by: Guenter Roeck <linux@...>
Link: https://lore.kernel.org/r/20220225175320.11041-7-biju.das.jz@bp.renesas.com
Signed-off-by: Guenter Roeck <linux@...>
Signed-off-by: Wim Van Sebroeck <wim@...>
Signed-off-by: Biju Das <biju.das.jz@...>
drivers/watchdog/rzg2l_wdt.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 73b667ed3e99..4e7107655cc2 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -21,8 +21,11 @@
#define WDTSET 0x04
#define WDTTIM 0x08
#define WDTINT 0x0C
+#define PECR 0x10
+#define PEEN 0x14
+#define PEEN_FORCE BIT(0)


@@ -117,17 +120,14 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev,
struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);

- /* Reset the module before we modify any register */
- reset_control_reset(priv->rstc);

- /* smallest counter value to reboot soon */
- rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(1), WDTSET);
+ /* Generate Reset (WDTRSTB) Signal on parity error */
+ rzg2l_wdt_write(priv, 0, PECR);

- /* Enable watchdog timer*/
- rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT);
+ /* Force parity error */
+ rzg2l_wdt_write(priv, PEEN_FORCE, PEEN);

return 0;

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