diff options
| author |   Andres Salomon <dilinger@queued.net> | 2010-12-21 13:04:42 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2010-12-23 15:31:48 -0800 |
| commit | 001851659354cce436b749a793f3512a53394d80 (patch) | |
| tree | cbce3c7d8f68c384229c40b915514b4668051d4a /drivers/gpio | |
| parent | Merge branch 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 (diff) | |
| download | linux-dev-001851659354cce436b749a793f3512a53394d80.tar.xz linux-dev-001851659354cce436b749a793f3512a53394d80.zip | |
cs5535-gpio: don't apply errata #36 to edge detect GPIOs
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!
Tested-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | 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 599f6c9e0fbf..79eb9c5a2923 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) |