Re: [PATCH v3 05/12] watchdog: s3c2410: Make reset disable register optional

From: Guenter Roeck <linux@roeck-us.net>
To: Sam Protsenko <semen.protsenko@linaro.org>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
	linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org
Subject: Re: [PATCH v3 05/12] watchdog: s3c2410: Make reset disable register optional
Date: Wed, 17 Nov 2021 05:35:12 -0800	[thread overview]
Message-ID: <20211117133512.GE2435591@roeck-us.net> (raw)
In-Reply-To: <20211107202943.8859-6-semen.protsenko@linaro.org>

On Sun, Nov 07, 2021 at 10:29:36PM +0200, 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@linaro.org>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> Changes in v3:
>   - Aligned arguments with opening parentheses
>   - Added R-b tag by Krzysztof Kozlowski
> 
> 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..2cc4923a98a5 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);
> +		if (ret < 0)
> +			goto error;
> +	}
>  
>  	ret = regmap_update_bits(wdt->pmureg,
>  			wdt->drv_data->mask_reset_reg,
> -- 
> 2.30.2
>