[PATCH 4.4 39/64] pinctrl: amd: use higher precision for 512 RtcClk

From: Greg Kroah-Hartman
Date: Tue Nov 17 2020 - 08:07:44 EST


From: Coiby Xu <coiby.xu@xxxxxxxxx>

commit c64a6a0d4a928c63e5bc3b485552a8903a506c36 upstream.

RTC is 32.768kHz thus 512 RtcClk equals 15625 usec. The documentation
likely has dropped precision and that's why the driver mistakenly took
the slightly deviated value.

Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Suggested-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Suggested-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Coiby Xu <coiby.xu@xxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Link: https://lore.kernel.org/linux-gpio/2f4706a1-502f-75f0-9596-cc25b4933b6c@xxxxxxxxxx/
Link: https://lore.kernel.org/r/20201105231912.69527-3-coiby.xu@xxxxxxxxx
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/pinctrl/pinctrl-amd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pinctrl/pinctrl-amd.c
+++ b/drivers/pinctrl/pinctrl-amd.c
@@ -144,7 +144,7 @@ static int amd_gpio_set_debounce(struct
pin_reg |= BIT(DB_TMR_OUT_UNIT_OFF);
pin_reg &= ~BIT(DB_TMR_LARGE_OFF);
} else if (debounce < 250000) {
- time = debounce / 15600;
+ time = debounce / 15625;
pin_reg |= time & DB_TMR_OUT_MASK;
pin_reg &= ~BIT(DB_TMR_OUT_UNIT_OFF);
pin_reg |= BIT(DB_TMR_LARGE_OFF);