| Message ID | 20201116215842.29488-1-mark.tomlinson@alliedtelesis.co.nz |
|---|---|
| State | New |
| Headers | show |
| Series | pinctrl: bcm: pinctrl-iproc-gpio: Fix setting GPIO as output | expand |
On 11/16/2020 1:58 PM, Mark Tomlinson wrote: > When setting a GPIO pin to an output, it is important to set the value > correctly before enabling the output so that a glitch is not seen on the > pin. This glitch may be very short, but can be important if this is a > reset signal. > > Fixes: b64333ce769c ("pinctrl: cygnus: add gpio/pinconf driver") > Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz> > --- > drivers/pinctrl/bcm/pinctrl-iproc-gpio.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c b/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c > index e2bd2dce6bb4..cadcf5eb0466 100644 > --- a/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c > +++ b/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c > @@ -348,8 +348,8 @@ static int iproc_gpio_direction_output(struct gpio_chip *gc, unsigned gpio, > unsigned long flags; > > raw_spin_lock_irqsave(&chip->lock, flags); > - iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, true); > iproc_set_bit(chip, IPROC_GPIO_DATA_OUT_OFFSET, gpio, !!(val)); > + iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, true); > raw_spin_unlock_irqrestore(&chip->lock, flags); > > dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val); > Thanks. The fix looks good. Would you be able to also help fix this in pinctrl-nsp-gpio.c ? Acked-by: Ray Jui <ray.jui@broadcom.com>
diff --git a/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c b/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c index e2bd2dce6bb4..cadcf5eb0466 100644 --- a/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c +++ b/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c @@ -348,8 +348,8 @@ static int iproc_gpio_direction_output(struct gpio_chip *gc, unsigned gpio, unsigned long flags; raw_spin_lock_irqsave(&chip->lock, flags); - iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, true); iproc_set_bit(chip, IPROC_GPIO_DATA_OUT_OFFSET, gpio, !!(val)); + iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, true); raw_spin_unlock_irqrestore(&chip->lock, flags); dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
When setting a GPIO pin to an output, it is important to set the value correctly before enabling the output so that a glitch is not seen on the pin. This glitch may be very short, but can be important if this is a reset signal. Fixes: b64333ce769c ("pinctrl: cygnus: add gpio/pinconf driver") Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz> --- drivers/pinctrl/bcm/pinctrl-iproc-gpio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)