Re: [PATCH v3 -next] Input: gpio_keys: set input direction explicitly for gpio keys

[Sudeep Holla]

On 17/11/16 01:18, Dmitry Torokhov wrote:
> On Wed, Nov 16, 2016 at 06:38:22PM +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        | 10 +++++++++-
> >  drivers/input/keyboard/gpio_keys_polled.c | 10 +++++++++-
> >  2 files changed, 18 insertions(+), 2 deletions(-)
> >
> > v2->v3:
> > 	- Added error handling and error message
> >
> > diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
> > index 5576f2ae0b71..ed38a05b3039 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;
>
> Sudeep, I looked into this aa bit deeper, and I have issue with this
> part: in absence of GPIOF_IN devm_gpio_request_one() will attempt to
> configure GPIO line as output, which may not work. Because of this I
> think we should move gpiod_direction_input() call into the "modern"
> branch and leave legacy branch as is.
>
> Does the version below work for you?

Yes it does and in fact I started with something similar and then saw
that I can make it common between legacy and new branch conditions. So I
am fine with the modified version you sent.

--
Regards,
Sudeep