linux-kernel - Re: [PATCH v2 05/12] watchdog: s3c2410: Make reset disable register optional

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Message-ID: <9846cb60-4628-0d06-4ec2-5687cfaefece@canonical.com>
Date:   Tue, 2 Nov 2021 10:52:32 +0100
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
To:     Sam Protsenko <semen.protsenko@...aro.org>,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        Guenter Roeck <linux@...ck-us.net>,
        Rob Herring <robh+dt@...nel.org>
Cc:     linux-watchdog@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org
Subject: Re: [PATCH v2 05/12] watchdog: s3c2410: Make reset disable register
 optional

On 31/10/2021 13:22, Sam Protsenko wrote:
> On new Exynos chips (e.g. Exynos850 and Exynos9) the
> AUTOMATIC_WDT_RESET_DISABLE register was removed, and its value can be
> thought of as "always 0x0". Add correspondig quirk bit, so that the
> driver can omit accessing it if it's not present.
> 
> This commit doesn't bring any functional change to existing devices, but
> merely provides an infrastructure for upcoming chips support.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@...aro.org>
> ---
> Changes in v2:
>   - Used quirks instead of callbacks for all added PMU registers
>   - Used BIT() macro
>   - Extracted splitting the s3c2410wdt_mask_and_disable_reset() function
>     to separate patch
>   - Extracted cleanup code to separate patch to minimize changes and
>     ease the review and porting
> 
>  drivers/watchdog/s3c2410_wdt.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 0845c05034a1..048ca47d0b8a 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -59,10 +59,12 @@
>  #define QUIRK_HAS_PMU_CONFIG			(1 << 0)
>  #define QUIRK_HAS_RST_STAT			(1 << 1)
>  #define QUIRK_HAS_WTCLRINT_REG			(1 << 2)
> +#define QUIRK_HAS_PMU_AUTO_DISABLE		(1 << 3)
>  
>  /* These quirks require that we have a PMU register map */
>  #define QUIRKS_HAVE_PMUREG			(QUIRK_HAS_PMU_CONFIG | \
> -						 QUIRK_HAS_RST_STAT)
> +						 QUIRK_HAS_RST_STAT | \
> +						 QUIRK_HAS_PMU_AUTO_DISABLE)
>  
>  static bool nowayout	= WATCHDOG_NOWAYOUT;
>  static int tmr_margin;
> @@ -137,7 +139,7 @@ static const struct s3c2410_wdt_variant drv_data_exynos5250  = {
>  	.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
>  	.rst_stat_bit = 20,
>  	.quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
> -		  | QUIRK_HAS_WTCLRINT_REG,
> +		  | QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_AUTO_DISABLE,
>  };
>  
>  static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
> @@ -147,7 +149,7 @@ static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
>  	.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
>  	.rst_stat_bit = 9,
>  	.quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
> -		  | QUIRK_HAS_WTCLRINT_REG,
> +		  | QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_AUTO_DISABLE,
>  };
>  
>  static const struct s3c2410_wdt_variant drv_data_exynos7 = {
> @@ -157,7 +159,7 @@ static const struct s3c2410_wdt_variant drv_data_exynos7 = {
>  	.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
>  	.rst_stat_bit = 23,	/* A57 WDTRESET */
>  	.quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
> -		  | QUIRK_HAS_WTCLRINT_REG,
> +		  | QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_AUTO_DISABLE,
>  };
>  
>  static const struct of_device_id s3c2410_wdt_match[] = {
> @@ -213,11 +215,13 @@ static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
>  	if (mask)
>  		val = mask_val;
>  
> -	ret = regmap_update_bits(wdt->pmureg,
> -			wdt->drv_data->disable_reg,
> -			mask_val, val);
> -	if (ret < 0)
> -		goto error;
> +	if (wdt->drv_data->quirks & QUIRK_HAS_PMU_AUTO_DISABLE) {
> +		ret = regmap_update_bits(wdt->pmureg,
> +				wdt->drv_data->disable_reg,
> +				mask_val, val);

While shuffling the code, please align the arguments with opening
parentheses.

Beside that looks ok:

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>

Best regards,
Krzysztof