[PATCH] soc: mediatek: PMIC wrap: Enable STAUPD_PRD before WDT_SRC_EN enabled.

[djkurtz@chromium.org (Daniel Kurtz)]

On Wed, Dec 30, 2015 at 8:36 PM, Henry Chen <henryc.chen@mediatek.com> wrote:
>
> The STAUPD_TRIG will be enable when WDT_INT enable on probe function, if
> doesn't enable STAUPD_PRD together, interrupt will be triggered because
> STAUPD timeout. To avoid unexpected interrupt, enable periodic status
> update which will be updated to PMIC every selected time period.

Sorry, I don't really understand this.

What exactly is triggering the unexpected watchdog interrupt (WDT_INT)?

How does setting STAUPD_PRD disable this "unexpected interrupt"?

>From the MT8173 Datasheet, I can see that the value written to
STAUPD_PRD is the "periodic status update timing (period)".

> Signed-off-by: Henry Chen <henryc.chen@mediatek.com>
> ---
>  drivers/soc/mediatek/mtk-pmic-wrap.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
> index a8cde17..6e5c20f 100644
> --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
> +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
> @@ -904,6 +904,11 @@ static int pwrap_probe(struct platform_device *pdev)
>                 return -ENODEV;
>         }
>
> +       /*
> +        * Enable periodic status update which will be updated to PMIC
> +        * every selected time period.
> +        */
> +       pwrap_writel(wrp, 0x5, PWRAP_STAUPD_PRD);

nit: Perhaps use a define for 5, and specify the real period value.
Something like this:

#define PWRAP_STAUPD_98_5US  5


>         /* Initialize watchdog, may not be done by the bootloader */
>         pwrap_writel(wrp, 0xf, PWRAP_WDT_UNIT);
>         pwrap_writel(wrp, 0xffffffff, PWRAP_WDT_SRC_EN);
> --
> 1.9.1
>
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