Re: [PATCH v3 12/12] watchdog: s3c2410: Add Exynos850 support

[Sam Protsenko <semen.protsenko@linaro.org>]

On Sat, 20 Nov 2021 at 22:29, Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 11/7/21 12:29 PM, Sam Protsenko wrote:
> > Exynos850 is a bit different from SoCs already supported in WDT driver:
> >    - AUTOMATIC_WDT_RESET_DISABLE register is removed, so its value is
> >      always 0; .disable_auto_reset callback is not set for that reason
> >    - MASK_WDT_RESET_REQUEST register is replaced with
> >      CLUSTERx_NONCPU_IN_EN register; instead of masking (disabling) WDT
> >      reset interrupt it's now enabled with the same value; .mask_reset
> >      callback is reused for that functionality though
> >    - To make WDT functional, WDT counter needs to be enabled in
> >      CLUSTERx_NONCPU_OUT register; it's done using .enable_counter
> >      callback
> >
> > Also Exynos850 has two CPU clusters, each has its own dedicated WDT
> > instance. Different PMU registers and bits are used for each cluster. So
> > driver data is now modified in probe, adding needed info depending on
> > cluster index passed from device tree.
> >
> > Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> > ---
> > Changes in v3:
> >    - Renamed "samsung,index" property to more descriptive
> >      "samsung,cluster-index"
> >    - Used pre-defined and completely set driver data for cluster0 and
> >      cluster1
> >
> > Changes in v2:
> >    - Used single compatible for Exynos850, populating missing driver data
> >      in probe
> >    - Added "index" property to specify CPU cluster index
> >
> >   drivers/watchdog/s3c2410_wdt.c | 62 +++++++++++++++++++++++++++++++++-
> >   1 file changed, 61 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> > index 96aa5d9c6ed4..1456201f27de 100644
> > --- a/drivers/watchdog/s3c2410_wdt.c
> > +++ b/drivers/watchdog/s3c2410_wdt.c
> > @@ -56,6 +56,13 @@
> >   #define EXYNOS5_RST_STAT_REG_OFFSET         0x0404
> >   #define EXYNOS5_WDT_DISABLE_REG_OFFSET              0x0408
> >   #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET   0x040c
> > +#define EXYNOS850_CLUSTER0_NONCPU_OUT                0x1220
> > +#define EXYNOS850_CLUSTER0_NONCPU_INT_EN     0x1244
> > +#define EXYNOS850_CLUSTER1_NONCPU_OUT                0x1620
> > +#define EXYNOS850_CLUSTER1_NONCPU_INT_EN     0x1644
> > +
> > +#define EXYNOS850_CLUSTER0_WDTRESET_BIT              24
> > +#define EXYNOS850_CLUSTER1_WDTRESET_BIT              23
> >
> >   /**
> >    * Quirk flags for different Samsung watchdog IP-cores.
> > @@ -205,6 +212,30 @@ static const struct s3c2410_wdt_variant drv_data_exynos7 = {
> >                 QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
> >   };
> >
> > +static const struct s3c2410_wdt_variant drv_data_exynos850_cl0 = {
> > +     .mask_reset_reg = EXYNOS850_CLUSTER0_NONCPU_INT_EN,
> > +     .mask_bit = 2,
> > +     .mask_reset_inv = true,
> > +     .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
> > +     .rst_stat_bit = EXYNOS850_CLUSTER0_WDTRESET_BIT,
> > +     .cnt_en_reg = EXYNOS850_CLUSTER0_NONCPU_OUT,
> > +     .cnt_en_bit = 7,
> > +     .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
> > +               QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
> > +};
> > +
> > +static const struct s3c2410_wdt_variant drv_data_exynos850_cl1 = {
> > +     .mask_reset_reg = EXYNOS850_CLUSTER1_NONCPU_INT_EN,
> > +     .mask_bit = 2,
> > +     .mask_reset_inv = true,
> > +     .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
> > +     .rst_stat_bit = EXYNOS850_CLUSTER1_WDTRESET_BIT,
> > +     .cnt_en_reg = EXYNOS850_CLUSTER1_NONCPU_OUT,
> > +     .cnt_en_bit = 7,
> > +     .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
> > +               QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
> > +};
> > +
> >   static const struct of_device_id s3c2410_wdt_match[] = {
> >       { .compatible = "samsung,s3c2410-wdt",
> >         .data = &drv_data_s3c2410 },
> > @@ -216,6 +247,8 @@ static const struct of_device_id s3c2410_wdt_match[] = {
> >         .data = &drv_data_exynos5420 },
> >       { .compatible = "samsung,exynos7-wdt",
> >         .data = &drv_data_exynos7 },
> > +     { .compatible = "samsung,exynos850-wdt",
> > +       .data = &drv_data_exynos850_cl0 },
> >       {},
> >   };
> >   MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
> > @@ -587,14 +620,38 @@ static inline const struct s3c2410_wdt_variant *
> >   s3c2410_get_wdt_drv_data(struct platform_device *pdev)
> >   {
> >       const struct s3c2410_wdt_variant *variant;
> > +     struct device *dev = &pdev->dev;
> >
> > -     variant = of_device_get_match_data(&pdev->dev);
> > +     variant = of_device_get_match_data(dev);
> >       if (!variant) {
> >               /* Device matched by platform_device_id */
> >               variant = (struct s3c2410_wdt_variant *)
> >                          platform_get_device_id(pdev)->driver_data;
> >       }
> >
> > +     /* Choose Exynos850 driver data w.r.t. cluster index */
> > +     if (variant == &drv_data_exynos850_cl0) {
>
> 0-day has a point here. drv_data_exynos850_cl0 is declared inside a CONFIG_OF
> conditional, causing compile failure if CONFIG_OF is not enabled.
>
> Please fix and resubmit.
>

Right. I missed that this driver has also platform device table. Will
send v4 soon.

> Guenter