gpio: mpc8xxx: don't modify gpdat when setting gpio as input
Since some chips don't support reading back the value of output gpios
from the gpdat register, we should not do a RMW cycle (i.e., the
clrbits_be32) on the gpdat register when setting a gpio as input, as
that might accidentally change the value of some other (still
configured as output) gpio.
The extra indirection through mpc8xxx_gpio_set_in() does not help
readability, so just fold the gpdir update into
mpc8xxx_gpio_direction_input().
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
diff --git a/drivers/gpio/mpc8xxx_gpio.c b/drivers/gpio/mpc8xxx_gpio.c
index c273c2c..d4f3092 100644
--- a/drivers/gpio/mpc8xxx_gpio.c
+++ b/drivers/gpio/mpc8xxx_gpio.c
@@ -57,13 +57,6 @@
return in_be32(&base->gpdir) & mask;
}
-static inline void mpc8xxx_gpio_set_in(struct ccsr_gpio *base, u32 gpios)
-{
- clrbits_be32(&base->gpdat, gpios);
- /* GPDIR register 0 -> input */
- clrbits_be32(&base->gpdir, gpios);
-}
-
static inline void mpc8xxx_gpio_set_low(struct ccsr_gpio *base, u32 gpios)
{
clrbits_be32(&base->gpdat, gpios);
@@ -100,8 +93,11 @@
static int mpc8xxx_gpio_direction_input(struct udevice *dev, uint gpio)
{
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
+ u32 mask = gpio_mask(gpio);
- mpc8xxx_gpio_set_in(data->base, gpio_mask(gpio));
+ /* GPDIR register 0 -> input */
+ clrbits_be32(&data->base->gpdir, mask);
+
return 0;
}