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Sender: Guenter Roeck <groeck7@gmail.com>
Date:   Sun, 25 Sep 2022 10:37:57 -0700
From:   Guenter Roeck <linux@roeck-us.net>
To:     "Alice Guo (OSS)" <alice.guo@oss.nxp.com>
Cc:     m.felsch@pengutronix.de, wim@linux-watchdog.org,
        shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com,
        kernel@pengutronix.de, linux-imx@nxp.com,
        linux-watchdog@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/7] watchdog: imx7ulp_wdt: Check CMD32EN in wdog init
Message-ID: <20220925173757.GC1763764@roeck-us.net>
References: <20220825083256.14565-1-alice.guo@oss.nxp.com>
 <20220825083256.14565-4-alice.guo@oss.nxp.com>
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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
>