| Message ID | 20200128120423.16667-2-rasmus.villemoes@prevas.dk |
|---|---|
| State | Accepted |
| Commit | 1d7ad9fa051e5b3057bccb6384ab62e4f9c206b2 |
| Headers | show |
| Series | gpio: mpc8xxx: honour shadow register when writing gpdat | expand |
On Tue, Jan 28, 2020 at 12:04:33PM +0000, Rasmus Villemoes wrote: > 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 at prevas.dk> Applied to u-boot/master, thanks!
diff --git a/drivers/gpio/mpc8xxx_gpio.c b/drivers/gpio/mpc8xxx_gpio.c index 9964d69035..5438196fe0 100644 --- a/drivers/gpio/mpc8xxx_gpio.c +++ b/drivers/gpio/mpc8xxx_gpio.c @@ -57,13 +57,6 @@ static inline u32 mpc8xxx_gpio_get_dir(struct ccsr_gpio *base, u32 mask) 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 inline void mpc8xxx_gpio_open_drain_off(struct ccsr_gpio *base, 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); + + /* GPDIR register 0 -> input */ + clrbits_be32(&data->base->gpdir, mask); - mpc8xxx_gpio_set_in(data->base, gpio_mask(gpio)); return 0; }
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 at prevas.dk> --- drivers/gpio/mpc8xxx_gpio.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)