On Fri, 29 Oct 2021 at 03:16, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> On 10/28/21 11:35 AM, Sam Protsenko wrote:
> > Not all SoCs have AUTOMATIC_WDT_RESET_DISABLE register, examples are
> > Exynos850 and Exynos9. On such chips reset disable register shouldn't be
> > accessed. Provide a way to avoid handling that register. This is done by
> > introducing separate callbacks to driver data structure: one for reset
> > disable register, and one for mask reset register. Now those callbacks
> > can be checked and called only when those were set in driver data.
> >
> > This commit doesn't bring any functional change to existing devices, but
> > merely provides an infrastructure for upcoming chips support.
> >
>
> That doesn't explain why the callbacks are needed instead of additional
> feature flags.
>
Ok, I'll rework this patch using quirks, don't have a strong
preference on this one. That's actually how I did that on my first
attempt. Guess I just like "callbacks way" more, matter of taste :)
But we already have quirks for that, so yeah, probably makes sense to
use those for consistency.
> Guenter
>
> > Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
> > ---
> > drivers/watchdog/s3c2410_wdt.c | 81 ++++++++++++++++++++++++----------
> > 1 file changed, 58 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> > index 2395f353e52d..7c163a257d3c 100644
> > --- a/drivers/watchdog/s3c2410_wdt.c
> > +++ b/drivers/watchdog/s3c2410_wdt.c
> > @@ -83,6 +83,8 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> > __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> > MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, 0 to reboot (default 0)");
> >
> > +struct s3c2410_wdt;
> > +
> > /**
> > * struct s3c2410_wdt_variant - Per-variant config data
> > *
> > @@ -96,6 +98,11 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, 0 to
> > * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
> > * reset.
> > * @quirks: A bitfield of quirks.
> > + * @disable_auto_reset: If set, this function will be called to disable
> > + * automatic setting the WDT as a reset reason in RST_STAT on CPU reset; uses
> > + * disable_reg field.
> > + * @mask_reset: If set, this function will be called to mask WDT reset request;
> > + * uses mask_reset_reg and mask_bit fields.
> > */
> >
> > struct s3c2410_wdt_variant {
> > @@ -105,6 +112,8 @@ struct s3c2410_wdt_variant {
> > int rst_stat_reg;
> > int rst_stat_bit;
> > u32 quirks;
> > + int (*disable_auto_reset)(struct s3c2410_wdt *wdt, bool mask);
> > + int (*mask_reset)(struct s3c2410_wdt *wdt, bool mask);
> > };
> >
> > struct s3c2410_wdt {
> > @@ -121,6 +130,9 @@ struct s3c2410_wdt {
> > struct regmap *pmureg;
> > };
> >
> > +static int s3c2410wdt_disable_wdt_reset(struct s3c2410_wdt *wdt, bool mask);
> > +static int s3c2410wdt_mask_wdt_reset(struct s3c2410_wdt *wdt, bool mask);
> > +
> > static const struct s3c2410_wdt_variant drv_data_s3c2410 = {
> > .quirks = 0
> > };
> > @@ -138,6 +150,8 @@ static const struct s3c2410_wdt_variant drv_data_exynos5250 = {
> > .rst_stat_bit = 20,
> > .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
> > | QUIRK_HAS_WTCLRINT_REG,
> > + .disable_auto_reset = s3c2410wdt_disable_wdt_reset,
> > + .mask_reset = s3c2410wdt_mask_wdt_reset,
> > };
> >
> > static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
> > @@ -148,6 +162,8 @@ static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
> > .rst_stat_bit = 9,
> > .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
> > | QUIRK_HAS_WTCLRINT_REG,
> > + .disable_auto_reset = s3c2410wdt_disable_wdt_reset,
> > + .mask_reset = s3c2410wdt_mask_wdt_reset,
> > };
> >
> > static const struct s3c2410_wdt_variant drv_data_exynos7 = {
> > @@ -158,6 +174,8 @@ static const struct s3c2410_wdt_variant drv_data_exynos7 = {
> > .rst_stat_bit = 23, /* A57 WDTRESET */
> > .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
> > | QUIRK_HAS_WTCLRINT_REG,
> > + .disable_auto_reset = s3c2410wdt_disable_wdt_reset,
> > + .mask_reset = s3c2410wdt_mask_wdt_reset,
> > };
> >
> > static const struct of_device_id s3c2410_wdt_match[] = {
> > @@ -200,35 +218,53 @@ static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
> > return container_of(nb, struct s3c2410_wdt, freq_transition);
> > }
> >
> > -static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
> > +static int s3c2410wdt_disable_wdt_reset(struct s3c2410_wdt *wdt, bool mask)
> > {
> > + const u32 mask_val = 1 << wdt->drv_data->mask_bit;
> > + const u32 val = mask ? mask_val : 0;
> > int ret;
> > - u32 mask_val = 1 << wdt->drv_data->mask_bit;
> > - u32 val = 0;
> >
> > - /* No need to do anything if no PMU CONFIG needed */
> > - if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG))
> > - return 0;
> > + ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->disable_reg,
> > + mask_val, val);
> > + if (ret < 0)
> > + dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> >
> > - if (mask)
> > - val = mask_val;
> > + return ret;
> > +}
> >
> > - ret = regmap_update_bits(wdt->pmureg,
> > - wdt->drv_data->disable_reg,
> > - mask_val, val);
> > - if (ret < 0)
> > - goto error;
> > +static int s3c2410wdt_mask_wdt_reset(struct s3c2410_wdt *wdt, bool mask)
> > +{
> > + const u32 mask_val = 1 << wdt->drv_data->mask_bit;
> > + const u32 val = mask ? mask_val : 0;
> > + int ret;
> >
> > - ret = regmap_update_bits(wdt->pmureg,
> > - wdt->drv_data->mask_reset_reg,
> > - mask_val, val);
> > - error:
> > + ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->mask_reset_reg,
> > + mask_val, val);
> > if (ret < 0)
> > dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> >
> > return ret;
> > }
> >
> > +static int s3c2410wdt_enable(struct s3c2410_wdt *wdt, bool en)
> > +{
> > + int ret;
> > +
> > + if (wdt->drv_data->disable_auto_reset) {
> > + ret = wdt->drv_data->disable_auto_reset(wdt, !en);
> > + if (ret < 0)
> > + return ret;
> > + }
> > +
> > + if (wdt->drv_data->mask_reset) {
> > + ret = wdt->drv_data->mask_reset(wdt, !en);
> > + if (ret < 0)
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
> > {
> > struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
> > @@ -609,7 +645,7 @@ 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;
> >
> > @@ -655,7 +691,7 @@ 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;
> >
> > @@ -672,8 +708,7 @@ 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);
> > }
> >
> > @@ -688,7 +723,7 @@ 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;
> >
> > @@ -708,7 +743,7 @@ 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;
> >
> >
>
