On Aug 11, 2009, at 4:04 AM, Felix Radensky wrote:
On MPC8536 Rev 1.0 the status of GPIO pins configured
as output cannot be determined by reading GPDAT register.
Workaround by reading the status of input pins from GPDAT
and the status of output pins from a shadow register.
Signed-off-by: Felix Radensky <fe...@embedded-sol.com>
---
arch/powerpc/sysdev/mpc8xxx_gpio.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/sysdev/mpc8xxx_gpio.c b/arch/powerpc/
sysdev/mpc8xxx_gpio.c
index 103eace..0b996f3 100644
--- a/arch/powerpc/sysdev/mpc8xxx_gpio.c
+++ b/arch/powerpc/sysdev/mpc8xxx_gpio.c
@@ -56,9 +56,13 @@ static void mpc8xxx_gpio_save_regs(struct
of_mm_gpio_chip *mm)
static int mpc8xxx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
{
+ u32 val;
struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
+ struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
+
+ val = in_be32(mm->regs + GPIO_DAT) && ~in_be32(mm->regs + GPIO_DIR);
it would be good to add a comment in the code about working around the
errata.
- return in_be32(mm->regs + GPIO_DAT) & mpc8xxx_gpio2mask(gpio);
+ return (val | mpc8xxx_gc->data) & mpc8xxx_gpio2mask(gpio);
}
static void mpc8xxx_gpio_set(struct gpio_chip *gc, unsigned int
gpio, int val)
--
1.5.4.3
- k
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