[PATCH v2 3/7] watchdog: imx7ulp_wdt: Check CMD32EN in wdog init

Alice Guo (OSS) posted 7 patches 3 years, 7 months ago
[PATCH v2 3/7] watchdog: imx7ulp_wdt: Check CMD32EN in wdog init
Posted by Alice Guo (OSS) 3 years, 7 months ago
From: Ye Li <ye.li@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@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>
---

Changes for v2:
 - none

 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
Re: [PATCH v2 3/7] watchdog: imx7ulp_wdt: Check CMD32EN in wdog init
Posted by Guenter Roeck 3 years, 6 months ago
On Thu, Aug 25, 2022 at 04:32:52PM +0800, Alice Guo (OSS) wrote:
> From: Ye Li <ye.li@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@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>

> ---
> 
> Changes for v2:
>  - none
> 
>  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
>