On Tue, Aug 11, 2009 at 12:04:18PM +0300, 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);
Are you sure about &&?
Plus, this are two reads instead of just one. I think it'll be better
to implement mpc8536_gpio_get(), and then do
if (of_device_is_compatible(np, ... 8536-gpio-bank ...))
gc->get = mpc8536_gpio_get;
else
gc->get = mpc8xxx_gpio_get;
> - 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)
Thanks,
--
Anton Vorontsov
email: cbouatmai...@gmail.com
irc://irc.freenode.net/bd2
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