[PATCH 5.3 067/135] watchdog: imx_sc_wdt: Pretimeout should follow SCU firmware format

[Greg Kroah-Hartman]

From: Anson Huang <Anson.Huang@xxxxxxx>

[ Upstream commit 2c50a6b825b3463a7600d6e6acadba73211c3d2c ]

SCU firmware calculates pretimeout based on current time stamp
instead of watchdog timeout stamp, need to convert the pretimeout
to SCU firmware's timeout value.

Fixes: 15f7d7fc5542 ("watchdog: imx_sc: Add pretimeout support")
Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/watchdog/imx_sc_wdt.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c
index 78eaaf75a263f..9545d1e07421a 100644
--- a/drivers/watchdog/imx_sc_wdt.c
+++ b/drivers/watchdog/imx_sc_wdt.c
@@ -99,8 +99,14 @@ static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog,
 {
 	struct arm_smccc_res res;
 
+	/*
+	 * SCU firmware calculates pretimeout based on current time
+	 * stamp instead of watchdog timeout stamp, need to convert
+	 * the pretimeout to SCU firmware's timeout value.
+	 */
 	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG,
-		      pretimeout * 1000, 0, 0, 0, 0, 0, &res);
+		      (wdog->timeout - pretimeout) * 1000, 0, 0, 0,
+		      0, 0, &res);
 	if (res.a0)
 		return -EACCES;
 
-- 
2.20.1