On Fri, 2013-11-15 at 15:16 +0800, Liu Gang wrote: > For MPC8572/MPC8536, the status of GPIOs defined as output > cannot be determined by reading GPDAT register, so the code > use shadow data register instead. But if the input pins are > asserted high, they will always read high due to the shadow > data, even if the pins are set to low. > > So the input pins should be read directly from GPDAT, not > the shadow data. > > Signed-off-by: Liu Gang <gang....@freescale.com> > --- > drivers/gpio/gpio-mpc8xxx.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c > index 9ae29cc..1d4ac75 100644 > --- a/drivers/gpio/gpio-mpc8xxx.c > +++ b/drivers/gpio/gpio-mpc8xxx.c > @@ -71,6 +71,7 @@ static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned > int gpio) > struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm); > > val = in_be32(mm->regs + GPIO_DAT) & ~in_be32(mm->regs + GPIO_DIR); > + mpc8xxx_gc->data &= in_be32(mm->regs + GPIO_DIR); > > return (val | mpc8xxx_gc->data) & mpc8xxx_gpio2mask(gpio); > }
It seems odd to update ->data in a function that's supposed to be reading things... Perhaps it would be better to keep ->data in a good state from the beginning. -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
