Re: [PATCH v2 -next] Input: gpio_keys: set input direction explicitly for gpio keys

From: Sudeep Holla
Date: Wed Nov 16 2016 - 12:42:24 EST

On 16/11/16 17:36, Dmitry Torokhov wrote:
On Wed, Nov 16, 2016 at 01:42:14PM +0000, Sudeep Holla wrote:
Commit 700a38b27eef ("Input: gpio_keys - switch to using generic device
properties") switched to use generic device properties for GPIO keys and
commit 5feeca3c1e39 ("Input: gpio_keys - add support for GPIO descriptors")
switched from legacy GPIO numbers to GPIO descriptors.

Previously devm_gpio_request_one was explicitly passed GPIOF_DIR_IN flag
to set the GPIO direction as input. However devm_get_gpiod_from_child
doesn't have such provisions and hence fwnode_get_named_gpiod can't set
it as input.

This breaks few platforms with the following error:
" gpiochip_lock_as_irq: tried to flag a GPIO set as output for IRQ
unable to lock HW IRQ <n> for IRQ
genirq: Failed to request resources for POWER (irq <x>) on irqchip
gpio_keys: Unable to claim irq <x>; error -22
gpio-keys: probe failed with error -22 "

This patch fixes the issue by setting input direction explicitly for
gpio input keys. It also remove the existing GPIOF_DIR_IN flag setting
for the legacy gpios and merges into single gpiod_direction_input call.

Fixes: 700a38b27eef ("Input: gpio_keys - switch to using generic device properties")
Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
drivers/input/keyboard/gpio_keys.c | 5 ++++-
drivers/input/keyboard/gpio_keys_polled.c | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)

- Fix the build(had sent a wrong version by accident)

Hi Dmitry,

The other option would be to pass the flag explicitly and add support to
handle it in the path devm_get_gpiod_from_child would take.

Hi Sudeep,

No, I think explicitly configuring it for input is good (at least for
now), but we need error handling.

Sure, a quick glance makes me think: all I need is to return the error
as everything is handled by devm_* APIs. If so I will respin with that
change, otherwise please let me know if I am missing anything here.