linux-kernel - Re: [PATCH] soc: mediatek: PMIC wrap: clear the STAUPD_TRIG bit of WDT_SRC

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Message-ID: <CAGS+omCFOUgTHxeUn0snrkBjvcR1bSOAAmkBHppF8nM37P1vrw@mail.gmail.com>
Date:	Wed, 20 Jan 2016 02:32:27 -0800
From:	Daniel Kurtz <djkurtz@...omium.org>
To:	Henry Chen <henryc.chen@...iatek.com>
Cc:	Matthias Brugger <matthias.bgg@...il.com>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"moderated list:ARM/Mediatek SoC support" 
	<linux-mediatek@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] soc: mediatek: PMIC wrap: clear the STAUPD_TRIG bit of WDT_SRC_EN

On Tue, Jan 19, 2016 at 8:52 PM, Henry Chen <henryc.chen@...iatek.com> wrote:
> Since STAUPD interrupts aren't handled on mt8173, disable watchdog timeout
> monitor of STAUPD to avoid WDT_INT triggered by STAUPD.
>
> Signed-off-by: Henry Chen <henryc.chen@...iatek.com>

> ---
>  drivers/soc/mediatek/mtk-pmic-wrap.c | 19 +++++++++++++++++--
>  1 file changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
> index af919b1..998f561 100644
> --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
> +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
> @@ -60,6 +60,15 @@
>  #define PWRAP_MAN_CMD_OP_OUTD          (0x9 << 8)
>  #define PWRAP_MAN_CMD_OP_OUTQ          (0xa << 8)
>
> +/* macro for Watch Dog Timer Source */
> +#define PWRAP_WDT_SRC_EN_STAUPD_TRIG           (1 << 25)
> +#define PWRAP_WDT_SRC_EN_HARB_STAUPD_DLE       (1 << 20)
> +#define PWRAP_WDT_SRC_EN_HARB_STAUPD_ALE       (1 << 6)
> +#define PWRAP_WDT_SRC_MASK_ALL                 0xffffffff
> +#define PWRAP_WDT_SRC_MASK_NO_STAUPD   ~(PWRAP_WDT_SRC_EN_STAUPD_TRIG | \
> +                                         PWRAP_WDT_SRC_EN_HARB_STAUPD_DLE | \
> +                                         PWRAP_WDT_SRC_EN_HARB_STAUPD_ALE)
> +
>  /* macro for slave device wrapper registers */
>  #define PWRAP_DEW_BASE                 0xbc00
>  #define PWRAP_DEW_EVENT_OUT_EN         (PWRAP_DEW_BASE + 0x0)
> @@ -830,7 +839,7 @@ MODULE_DEVICE_TABLE(of, of_pwrap_match_tbl);
>
>  static int pwrap_probe(struct platform_device *pdev)
>  {
> -       int ret, irq;
> +       int ret, irq, wdt_src;
>         struct pmic_wrapper *wrp;
>         struct device_node *np = pdev->dev.of_node;
>         const struct of_device_id *of_id =
> @@ -920,7 +929,13 @@ static int pwrap_probe(struct platform_device *pdev)
>
>         /* Initialize watchdog, may not be done by the bootloader */
>         pwrap_writel(wrp, 0xf, PWRAP_WDT_UNIT);
> -       pwrap_writel(wrp, 0xffffffff, PWRAP_WDT_SRC_EN);
> +       /*
> +        * Since STAUPD was not used on mt8173 platform,
> +        * so STAUPD of WDT_SRC which should be turned off
> +        */

It is a little awkward that "!pwrap_is_mt8135(wrp)" means mt8173.  Is
this always true?
Why aren't we clearing STAUPD for mt8135 too?
I assume it is because mt8135 does not define this bit?
What about other devices that are not mt8135 or mt8173?

Perhaps change the comment to:
"This driver does not use STAUPD, so clear this WDT SRC for all
devices for which it exists to avoid unhandled interrupts"

Other than that, this patch is:
Reviewed-by: Daniel Kurtz <djkurtz@...omium.org>

> +       wdt_src = pwrap_is_mt8135(wrp) ?
> +                       PWRAP_WDT_SRC_MASK_ALL : PWRAP_WDT_SRC_MASK_NO_STAUPD;
> +       pwrap_writel(wrp, wdt_src, PWRAP_WDT_SRC_EN);
>         pwrap_writel(wrp, 0x1, PWRAP_TIMER_EN);
>         pwrap_writel(wrp, ~((1 << 31) | (1 << 1)), PWRAP_INT_EN);
>
> --
> 1.8.1.1.dirty
>