From mboxrd@z Thu Jan 1 00:00:00 1970 From: henryc.chen@mediatek.com (Henry Chen) Date: Mon, 4 Jan 2016 11:05:03 +0800 Subject: [PATCH] soc: mediatek: PMIC wrap: Enable STAUPD_PRD before WDT_SRC_EN enabled. In-Reply-To: References: <1451478961-5668-1-git-send-email-henryc.chen@mediatek.com> Message-ID: <1451876703.11408.10.camel@mtksdaap41> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 2015-12-31 at 22:19 +0800, Daniel Kurtz wrote: > On Wed, Dec 30, 2015 at 8:36 PM, Henry Chen 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"? > Yes, WDT_INT was triggered because the bit[25] of WDT_SRC_EN was enabled: bit[25] STAUPD_TRIG: STAUPD trigger signal timeout monitor Setting STAUPD_PRD will update the status of PMIC periodic to avoid this watchdog timeout. > 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 > > --- > > 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 > ok. > > > /* 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 majordomo at vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/