Messages in this thread | | | Date | Fri, 17 Dec 2010 18:09:48 -0800 | From | Andres Salomon <> | Subject | Re: [PATCH 1/2] cs5535-gpio: don't apply errata #36 to edge detect GPIOs |
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Note: these two patches fix problems with commit 853ff883, so they should definitely go in for 3.6.37.
On Wed, 15 Dec 2010 11:28:07 -0800 Andres Salomon <dilinger@queued.net> wrote:
> > The edge detect status GPIOs function differently from the other > atomic model CS5536 GPIO registers; writing 1 to the high bits clears > the GPIO, but writing 1 to the lower bits also clears the bit. This > means that read-modify-write doesn't actually work for it, so don't > apply the errata here. If a negative edge status gets lost after > resume.. well, we tried our best! > > Signed-off-by: Andres Salomon <dilinger@queued.net> > Tested-by: Daniel Drake <dsd@laptop.org> > --- > drivers/gpio/cs5535-gpio.c | 15 +++++++++++---- > 1 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpio/cs5535-gpio.c b/drivers/gpio/cs5535-gpio.c > index 599f6c9..79eb9c5 100644 > --- a/drivers/gpio/cs5535-gpio.c > +++ b/drivers/gpio/cs5535-gpio.c > @@ -56,15 +56,22 @@ static struct cs5535_gpio_chip { > * registers, see include/linux/cs5535.h. > */ > > -static void errata_outl(u32 val, unsigned long addr) > +static void errata_outl(struct cs5535_gpio_chip *chip, u32 val, > + unsigned int reg) > { > + unsigned long addr = chip->base + 0x80 + reg; > + > /* > * According to the CS5536 errata (#36), after suspend > * a write to the high bank GPIO register will clear all > * non-selected bits; the recommended workaround is a > * read-modify-write operation. > + * > + * Don't apply this errata to the edge status GPIOs, as > writing > + * to their lower bits will clear them. > */ > - val |= inl(addr); > + if (reg != GPIO_POSITIVE_EDGE_STS && reg != > GPIO_NEGATIVE_EDGE_STS) > + val |= inl(addr); > outl(val, addr); > } > > @@ -76,7 +83,7 @@ static void __cs5535_gpio_set(struct > cs5535_gpio_chip *chip, unsigned offset, outl(1 << offset, chip->base > + reg); else > /* high bank register */ > - errata_outl(1 << (offset - 16), chip->base + 0x80 + > reg); > + errata_outl(chip, 1 << (offset - 16), reg); > } > > void cs5535_gpio_set(unsigned offset, unsigned int reg) > @@ -98,7 +105,7 @@ static void __cs5535_gpio_clear(struct > cs5535_gpio_chip *chip, unsigned offset, outl(1 << (offset + 16), > chip->base + reg); else > /* high bank register */ > - errata_outl(1 << offset, chip->base + 0x80 + reg); > + errata_outl(chip, 1 << offset, reg); > } > > void cs5535_gpio_clear(unsigned offset, unsigned int reg)
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