2015-12-30 12:36:17

by Henry Chen

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

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.

Signed-off-by: Henry Chen <[email protected]>
---
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);
/* 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

2015-12-31 14:19:26

by Daniel Kurtz

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

On Wed, Dec 30, 2015 at 8:36 PM, Henry Chen <[email protected]> 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 <[email protected]>
> ---
> 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
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/