Thread (5 messages) 5 messages, 2 authors, 2016-01-06

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

From: Daniel Kurtz <hidden>
Date: 2015-12-31 14:19:26
Also in: linux-arm-kernel, lkml

On Wed, Dec 30, 2015 at 8:36 PM, Henry Chen [off-list ref] 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)".
quoted hunk ↗ jump to hunk
Signed-off-by: Henry Chen <henryc.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
 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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