watchdog: imx7ulp_wdt: Check CMD32EN in wdog init

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@nxp.com>
Signed-off-by: Alice Guo <alice.guo@nxp.com>
Reviewed-by: Jacky Bai <ping.bai@nxp.com>
Acked-by: Jason Liu <jason.hui.liu@nxp.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220825083256.14565-4-alice.guo@oss.nxp.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/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
index b8ac0cb..a0f6b8c 100644 (file)
--- 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)