MIME-Version: 1.0
References: <20211121165647.26706-1-semen.protsenko@linaro.org>
 <20211121165647.26706-10-semen.protsenko@linaro.org> <20211123160623.GB2326185@roeck-us.net>
In-Reply-To: <20211123160623.GB2326185@roeck-us.net>
From:   Sam Protsenko <semen.protsenko@linaro.org>
Date:   Tue, 23 Nov 2021 18:17:01 +0200
Message-ID: <CAPLW+4mwhH5C6zSxWDboNucZPvt2c=F7Qaa9V_XJHbJzbFNL3w@mail.gmail.com>
Subject: Re: [PATCH v4 09/12] watchdog: s3c2410: Cleanup PMU related code
To:     Guenter Roeck <linux@roeck-us.net>
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
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, 23 Nov 2021 at 18:06, Guenter Roeck <linux@roeck-us.net> wrote:
>
> On Sun, Nov 21, 2021 at 06:56:44PM +0200, Sam Protsenko wrote:
> > Now that PMU enablement code was extended for new Exynos SoCs, it
> > doesn't look very cohesive and consistent anymore. Do a bit of renaming,
> > grouping and style changes, to make it look good again. While at it, add
> > quirks documentation as well.
> >
> > No functional change, just a refactoring commit.
> >
> > 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 v4:
> >   - Added R-b tag by Guenter Roeck
> >
> > Changes in v3:
> >   - Added quirks documentation
> >   - Added R-b tag by Krzysztof Kozlowski
> >
> > Changes in v2:
> >   - (none): it's a new patch
> >
> >  drivers/watchdog/s3c2410_wdt.c | 83 ++++++++++++++++++++++++----------
> >  1 file changed, 58 insertions(+), 25 deletions(-)
> >
> > diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> > index ec341c876225..f211be8bf976 100644
> > --- a/drivers/watchdog/s3c2410_wdt.c
> > +++ b/drivers/watchdog/s3c2410_wdt.c
> > @@ -56,17 +56,51 @@
> >  #define EXYNOS5_RST_STAT_REG_OFFSET          0x0404
> >  #define EXYNOS5_WDT_DISABLE_REG_OFFSET               0x0408
> >  #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET    0x040c
> > -#define QUIRK_HAS_PMU_CONFIG                 (1 << 0)
> > -#define QUIRK_HAS_RST_STAT                   (1 << 1)
> > -#define QUIRK_HAS_WTCLRINT_REG                       (1 << 2)
> > +
> > +/**
>
> 0-day complains:
>
> drivers/watchdog/s3c2410_wdt.c:94: warning: expecting prototype for Quirk flags for different Samsung watchdog IP(). Prototype was for QUIRK_HAS_WTCLRINT_REG() instead
>
> It doesn't seem to like the idea of documented bit masks. Not really sure
> what to do here. I am inclined to ignore it, but I don't want to get flooded
> by 0-day complaints until I retire either. Any idea ?
>

Seems like 0-day thinks this kernel-doc comment is for the first
define only, and thus the comment has wrong format, or something like
that. I tried to follow the same style as GFP_KERNEL and others are
documented.

Anyway, if you don't like 0-day complaints, can you please just
replace kernel-doc comment (/**) with regular comment (/*), by
removing one asterisk in the patch? Or I can re-send the patch
correspondingly -- then just let me know.

> Guenter
>
> > + * Quirk flags for different Samsung watchdog IP-cores.
> > + *
> > + * This driver supports multiple Samsung SoCs, each of which might have
> > + * different set of registers and features supported. As watchdog block
> > + * sometimes requires modifying PMU registers for proper functioning, register
> > + * differences in both watchdog and PMU IP-cores should be accounted for. Quirk
> > + * flags described below serve the purpose of telling the driver about mentioned
> > + * SoC traits, and can be specified in driver data for each particular supported
> > + * device.
> > + *
> > + * %QUIRK_HAS_WTCLRINT_REG: Watchdog block has WTCLRINT register. It's used to
> > + * clear the interrupt once the interrupt service routine is complete. It's
> > + * write-only, writing any values to this register clears the interrupt, but
> > + * reading is not permitted.
> > + *
> > + * %QUIRK_HAS_PMU_MASK_RESET: PMU block has the register for disabling/enabling
> > + * WDT reset request. On old SoCs it's usually called MASK_WDT_RESET_REQUEST,
> > + * new SoCs have CLUSTERx_NONCPU_INT_EN register, which 'mask_bit' value is
> > + * inverted compared to the former one.
> > + *
> > + * %QUIRK_HAS_PMU_RST_STAT: PMU block has RST_STAT (reset status) register,
> > + * which contains bits indicating the reason for most recent CPU reset. If
> > + * present, driver will use this register to check if previous reboot was due to
> > + * watchdog timer reset.
> > + *
> > + * %QUIRK_HAS_PMU_AUTO_DISABLE: PMU block has AUTOMATIC_WDT_RESET_DISABLE
> > + * register. If 'mask_bit' bit is set, PMU will disable WDT reset when
> > + * corresponding processor is in reset state.
> > + *
> > + * %QUIRK_HAS_PMU_CNT_EN: PMU block has some register (e.g. CLUSTERx_NONCPU_OUT)
> > + * with "watchdog counter enable" bit. That bit should be set to make watchdog
> > + * counter running.
> > + */
> > +#define QUIRK_HAS_WTCLRINT_REG                       (1 << 0)
> > +#define QUIRK_HAS_PMU_MASK_RESET             (1 << 1)
> > +#define QUIRK_HAS_PMU_RST_STAT                       (1 << 2)
> >  #define QUIRK_HAS_PMU_AUTO_DISABLE           (1 << 3)
> >  #define QUIRK_HAS_PMU_CNT_EN                 (1 << 4)
> >
> >  /* These quirks require that we have a PMU register map */
> > -#define QUIRKS_HAVE_PMUREG                   (QUIRK_HAS_PMU_CONFIG | \
> > -                                              QUIRK_HAS_RST_STAT | \
> > -                                              QUIRK_HAS_PMU_AUTO_DISABLE | \
> > -                                              QUIRK_HAS_PMU_CNT_EN)
> > +#define QUIRKS_HAVE_PMUREG \
> > +     (QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_RST_STAT | \
> > +      QUIRK_HAS_PMU_AUTO_DISABLE | QUIRK_HAS_PMU_CNT_EN)
> >
> >  static bool nowayout = WATCHDOG_NOWAYOUT;
> >  static int tmr_margin;
> > @@ -146,8 +180,8 @@ static const struct s3c2410_wdt_variant drv_data_exynos5250  = {
> >       .mask_bit = 20,
> >       .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_PMU_AUTO_DISABLE,
> > +     .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
> > +               QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
> >  };
> >
> >  static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
> > @@ -156,8 +190,8 @@ static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
> >       .mask_bit = 0,
> >       .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_PMU_AUTO_DISABLE,
> > +     .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
> > +               QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
> >  };
> >
> >  static const struct s3c2410_wdt_variant drv_data_exynos7 = {
> > @@ -166,8 +200,8 @@ static const struct s3c2410_wdt_variant drv_data_exynos7 = {
> >       .mask_bit = 23,
> >       .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_PMU_AUTO_DISABLE,
> > +     .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
> > +               QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
> >  };
> >
> >  static const struct of_device_id s3c2410_wdt_match[] = {
> > @@ -253,24 +287,24 @@ static int s3c2410wdt_enable_counter(struct s3c2410_wdt *wdt, bool en)
> >       return ret;
> >  }
> >
> > -static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
> > +static int s3c2410wdt_enable(struct s3c2410_wdt *wdt, bool en)
> >  {
> >       int ret;
> >
> >       if (wdt->drv_data->quirks & QUIRK_HAS_PMU_AUTO_DISABLE) {
> > -             ret = s3c2410wdt_disable_wdt_reset(wdt, mask);
> > +             ret = s3c2410wdt_disable_wdt_reset(wdt, !en);
> >               if (ret < 0)
> >                       return ret;
> >       }
> >
> > -     if (wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG) {
> > -             ret = s3c2410wdt_mask_wdt_reset(wdt, mask);
> > +     if (wdt->drv_data->quirks & QUIRK_HAS_PMU_MASK_RESET) {
> > +             ret = s3c2410wdt_mask_wdt_reset(wdt, !en);
> >               if (ret < 0)
> >                       return ret;
> >       }
> >
> >       if (wdt->drv_data->quirks & QUIRK_HAS_PMU_CNT_EN) {
> > -             ret = s3c2410wdt_enable_counter(wdt, !mask);
> > +             ret = s3c2410wdt_enable_counter(wdt, en);
> >               if (ret < 0)
> >                       return ret;
> >       }
> > @@ -531,7 +565,7 @@ static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
> >       unsigned int rst_stat;
> >       int ret;
> >
> > -     if (!(wdt->drv_data->quirks & QUIRK_HAS_RST_STAT))
> > +     if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_RST_STAT))
> >               return 0;
> >
> >       ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
> > @@ -672,7 +706,7 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
> >       if (ret)
> >               goto err_cpufreq;
> >
> > -     ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
> > +     ret = s3c2410wdt_enable(wdt, true);
> >       if (ret < 0)
> >               goto err_unregister;
> >
> > @@ -707,7 +741,7 @@ static int s3c2410wdt_remove(struct platform_device *dev)
> >       int ret;
> >       struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
> >
> > -     ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
> > +     ret = s3c2410wdt_enable(wdt, false);
> >       if (ret < 0)
> >               return ret;
> >
> > @@ -724,8 +758,7 @@ static void s3c2410wdt_shutdown(struct platform_device *dev)
> >  {
> >       struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
> >
> > -     s3c2410wdt_mask_and_disable_reset(wdt, true);
> > -
> > +     s3c2410wdt_enable(wdt, false);
> >       s3c2410wdt_stop(&wdt->wdt_device);
> >  }
> >
> > @@ -740,7 +773,7 @@ static int s3c2410wdt_suspend(struct device *dev)
> >       wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
> >       wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
> >
> > -     ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
> > +     ret = s3c2410wdt_enable(wdt, false);
> >       if (ret < 0)
> >               return ret;
> >
> > @@ -760,7 +793,7 @@ static int s3c2410wdt_resume(struct device *dev)
> >       writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
> >       writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
> >
> > -     ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
> > +     ret = s3c2410wdt_enable(wdt, true);
> >       if (ret < 0)
> >               return ret;
> >
> > --
> > 2.30.2
> >