[PATCH v5 15/20] watchdog: s3c2410_wdt: Add support for WTCON register DBGACK_MASK bit

[Peter Griffin]

Hi Sam,

On Sat, 2 Dec 2023 at 00:53, Sam Protsenko <semen.protsenko at linaro.org> wrote:
>
> On Fri, Dec 1, 2023 at 10:11 AM Peter Griffin <peter.griffin at linaro.org> wrote:
> >
> > The WDT uses the CPU core signal DBGACK to determine whether the SoC
> > is running in debug mode or not. If the DBGACK signal is asserted and
> > DBGACK_MASK bit is enabled, then WDT output and interrupt is masked
> > (disabled).
> >
> > Presence of the DBGACK_MASK bit is determined by adding a new
> > QUIRK_HAS_DBGACK_BIT quirk.
> >
> > Signed-off-by: Peter Griffin <peter.griffin at linaro.org>
> > ---
> >  drivers/watchdog/s3c2410_wdt.c | 27 ++++++++++++++++++++++++---
> >  1 file changed, 24 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> > index 0b4bd883ff28..39f3489e41d6 100644
> > --- a/drivers/watchdog/s3c2410_wdt.c
> > +++ b/drivers/watchdog/s3c2410_wdt.c
> > @@ -34,9 +34,10 @@
> >
> >  #define S3C2410_WTCNT_MAXCNT   0xffff
> >
> > -#define S3C2410_WTCON_RSTEN    (1 << 0)
> > -#define S3C2410_WTCON_INTEN    (1 << 2)
> > -#define S3C2410_WTCON_ENABLE   (1 << 5)
> > +#define S3C2410_WTCON_RSTEN            (1 << 0)
> > +#define S3C2410_WTCON_INTEN            (1 << 2)
> > +#define S3C2410_WTCON_ENABLE           (1 << 5)
> > +#define S3C2410_WTCON_DBGACK_MASK      (1 << 16)
>
> Suggest using BIT() macro. Btw, checkpatch with --strict option
> suggests it too :)

Yes indeed. I was somewhat reluctant to include changes that had
nothing to do with the DBGACK feature but I will update to use the BIT
macro in v6.
>
> >
> >  #define S3C2410_WTCON_DIV16    (0 << 3)
> >  #define S3C2410_WTCON_DIV32    (1 << 3)
> > @@ -100,12 +101,17 @@
> >   * %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.
> > + *
> > + * %QUIRK_HAS_DBGACK_BIT: WTCON register has DBGACK_MASK bit. Setting the
> > + * DBGACK_MASK bit disables the watchdog outputs when the SoC is in debug mode.
> > + * Debug mode is determined by the DBGACK CPU signal.
> >   */
> >  #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)
> > +#define QUIRK_HAS_DBGACK_BIT                   (1 << 5)
> >
> >  /* These quirks require that we have a PMU register map */
> >  #define QUIRKS_HAVE_PMUREG \
> > @@ -375,6 +381,19 @@ static int s3c2410wdt_enable(struct s3c2410_wdt *wdt, bool en)
> >         return 0;
> >  }
> >
> > +static void s3c2410wdt_mask_dbgack(struct s3c2410_wdt *wdt)
> > +{
> > +       unsigned long wtcon;
> > +
> > +       if (!(wdt->drv_data->quirks & QUIRK_HAS_DBGACK_BIT))
> > +               return;
> > +
> > +       /*  disable watchdog outputs if CPU is in debug mode */
>
> Double whitespace in the comment. Also, I'd move this comment up to
> the function declaration.

Will fix

>
> Other than that:
>
> Reviewed-by: Sam Protsenko <semen.protsenko at linaro.org>

Thanks,

Peter
>
> > +       wtcon = readl(wdt->reg_base + S3C2410_WTCON);
> > +       wtcon |= S3C2410_WTCON_DBGACK_MASK;
> > +       writel(wtcon, wdt->reg_base + S3C2410_WTCON);
> > +}
> > +
> >  static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
> >  {
> >         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
> > @@ -700,6 +719,8 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
> >         wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
> >         wdt->wdt_device.parent = dev;
> >
> > +       s3c2410wdt_mask_dbgack(wdt);
> > +
> >         /*
> >          * If "tmr_atboot" param is non-zero, start the watchdog right now. Also
> >          * set WDOG_HW_RUNNING bit, so that watchdog core can kick the watchdog.
> > --
> > 2.43.0.rc2.451.g8631bc7472-goog
> >