pinctrl: amd: use higher precision for 512 RtcClk

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

diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
index eab078244a4c3e8c4c6bfea829e41edab62f76c4..3918f4fb3962acfa02df0c38e1db78d249b2945d 100644 (file)
--- a/drivers/pinctrl/pinctrl-amd.c
+++ b/drivers/pinctrl/pinctrl-amd.c
@@ -153,7 +153,7 @@ static int amd_gpio_set_debounce(struct gpio_chip *gc, unsigned offset,
                        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);