[PATCH 3/7] watchdog: imx7ulp_wdt: Check CMD32EN in wdog init

[Alice Guo (OSS)]

From: Ye Li <ye.li at nxp.com>

When bootloader has enabled the CMD32EN bit, switch to use 32bits
unlock command to unlock the CS register. Using 32bits command will
help on avoiding 16 bus cycle window violation for two 16 bits
commands.

Signed-off-by: Ye Li <ye.li at nxp.com>
Signed-off-by: Alice Guo <alice.guo at nxp.com>
Reviewed-by: Jacky Bai <ping.bai at nxp.com>
Acked-by: Jason Liu <jason.hui.liu at nxp.com>
---
 drivers/watchdog/imx7ulp_wdt.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
index b8ac0cb04d2f..a0f6b8cea78f 100644
--- a/drivers/watchdog/imx7ulp_wdt.c
+++ b/drivers/watchdog/imx7ulp_wdt.c
@@ -180,11 +180,16 @@ static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
 
 	local_irq_disable();
 
-	mb();
-	/* unlock the wdog for reconfiguration */
-	writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
-	writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
-	mb();
+	val = readl(base + WDOG_CS);
+	if (val & WDOG_CS_CMD32EN) {
+		writel(UNLOCK, base + WDOG_CNT);
+	} else {
+		mb();
+		/* unlock the wdog for reconfiguration */
+		writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
+		writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
+		mb();
+	}
 
 	ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK);
 	if (ret)
-- 
2.17.1