Re: [PATCH 1/1] [INPUT/KEYPAD] gpio keypad: Replace current blackfin specific pfbutton driver with kernel generic gpio key driver

[Mike Frysinger]

On Mon, May 12, 2008 at 8:11 AM, Bryan Wu <cooloney@xxxxxxxxxx> wrote:
> On Mon, May 12, 2008 at 7:42 PM, Mike Frysinger <vapier.adi@xxxxxxxxx> wrote:
>> On Mon, May 12, 2008 at 7:27 AM, pHilipp Zabel
<philipp.zabel@xxxxxxxxx> wrote:
>>  > On Mon, May 12, 2008 at 12:17 PM, Bryan Wu <cooloney@xxxxxxxxxx> wrote:
>>  >> From: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
>>  >>
>>  >>  It's an actual deficiency in the hardware that we can't address,
>>  >>  so it needs to be worked around in software.
>>  >>
>>  >>  Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
>>  >>  Signed-off-by: Bryan Wu <cooloney@xxxxxxxxxx>
>>  >>  ---
>>  >>   drivers/input/keyboard/gpio_keys.c |   15 ++++++++++++++-
>>  >>   1 files changed, 14 insertions(+), 1 deletions(-)
>>  >>
>>  >>  diff --git a/drivers/input/keyboard/gpio_keys.c
>>  b/drivers/input/keyboard/gpio_keys.c
>>  >>  index bbd00c3..d856eb9 100644
>>  >>  --- a/drivers/input/keyboard/gpio_keys.c
>>  >>  +++ b/drivers/input/keyboard/gpio_keys.c
>>  >>  @@ -26,6 +26,18 @@
>>  >>
>>  >>   #include <asm/gpio.h>
>>  >>
>>  >>  +#if defined(CONFIG_BLACKFIN) && !defined(BF548_FAMILY)
>>  >>  +
>>  >>  +/*
>>  >>  + * On some Blackfin CPUs reading edge triggered
>>  >>  + * GPIOs doesn't return the current value
>>  >>  + */
>>  >
>>  > If this is a generic problem, shouldn't this be addressed inside
gpio_get_value?
>>
>>  it's an issue only when the GPIO is an interrupt source and the
>>  trigger condition is set to both rising and falling.  but i guess your
>>  point is that in gpio_get_value(), we can check to see if these
>>  conditions are met and if so, temporarily fiddle things there ?
>>
>>  Michael: that sounds reasonable, what do you think ?
>
> IMO, maybe it is feasible for fix this in generic GPIO layer, or will
> break other things?

where are you referring to ?  i think what's being proposed is to move
these checks to arch/blackfin/kernel/bfin_gpio.c ... any call to
gpio_get_value() under these circumstances will need the edge sense
toggle ...
-mike
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