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

From: Sudeep Holla
Date: Wed Nov 16 2016 - 08:42:28 EST


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(-)

v1->v2:
- 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.

Let me know your opinion.

Regards,
Sudeep

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 5576f2ae0b71..f5e2d377f5c1 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -502,7 +502,7 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
* Legacy GPIO number, so request the GPIO here and
* convert it to descriptor.
*/
- unsigned flags = GPIOF_IN;
+ unsigned flags = 0;

if (button->active_low)
flags |= GPIOF_ACTIVE_LOW;
@@ -521,6 +521,9 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
}

if (bdata->gpiod) {
+ /* set the GPIO direction to input */
+ gpiod_direction_input(bdata->gpiod);
+
if (button->debounce_interval) {
error = gpiod_set_debounce(bdata->gpiod,
button->debounce_interval * 1000);
diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index 72b350315d43..56bf0dc5e2e4 100644
--- a/drivers/input/keyboard/gpio_keys_polled.c
+++ b/drivers/input/keyboard/gpio_keys_polled.c
@@ -319,7 +319,7 @@ static int gpio_keys_polled_probe(struct platform_device *pdev)
* Legacy GPIO number so request the GPIO here and
* convert it to descriptor.
*/
- unsigned flags = GPIOF_IN;
+ unsigned flags = 0;

if (button->active_low)
flags |= GPIOF_ACTIVE_LOW;
@@ -342,6 +342,9 @@ static int gpio_keys_polled_probe(struct platform_device *pdev)
}
}

+ /* set the GPIO direction to input */
+ gpiod_direction_input(bdata->gpiod);
+
bdata->last_state = -1;
bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
pdata->poll_interval);
--
2.7.4