RE: [PATCH v3 01/10] input: keyboard: adp5588-keys: support gpi key events as 'gpio keys'

["Sa, Nuno" <Nuno.Sa@xxxxxxxxxx>]

> From: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Sent: Wednesday, August 31, 2022 2:24 PM
> To: Sa, Nuno <Nuno.Sa@xxxxxxxxxx>
> Cc: linux-input@xxxxxxxxxxxxxxx; linux-gpio@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; Krzysztof Kozlowski
> <krzysztof.kozlowski+dt@xxxxxxxxxx>; Hennerich, Michael
> <Michael.Hennerich@xxxxxxxxxx>; Bartosz Golaszewski
> <brgl@xxxxxxxx>; Andy Shevchenko <andy.shevchenko@xxxxxxxxx>;
> Rob Herring <robh+dt@xxxxxxxxxx>; Dmitry Torokhov
> <dmitry.torokhov@xxxxxxxxx>
> Subject: Re: [PATCH v3 01/10] input: keyboard: adp5588-keys: support
> gpi key events as 'gpio keys'
> 
> [External]
> 
> On Thu, Jul 21, 2022 at 10:03 AM Nuno Sá <nuno.sa@xxxxxxxxxx>
> wrote:
> 
> > This change replaces the support for GPIs as key event generators.
> > Instead of reporting the events directly, we add a gpio based irqchip
> > so that these events can be consumed by keys defined in the gpio-
> keys
> > driver (as it's goal is indeed for keys on GPIOs capable of generating
> > interrupts). With this, the gpio-adp5588 driver can also be dropped.
> >
> > The basic idea is that all the pins that are not being used as part of
> > the keymap matrix can be possibly requested as GPIOs by gpio-keys
> > (it's also fine to use these pins as plain interrupts though that's not
> > really the point).
> >
> > Since the gpiochip now also has irqchip capabilities, we should only
> > remove it after we free the device interrupt (otherwise we could, in
> > theory, be handling GPIs interrupts while the gpiochip is concurrently
> > removed). Thus the call 'adp5588_gpio_add()' is moved and since the
> > setup phase also needs to come before making the gpios visible, we
> also
> > need to move 'adp5588_setup()'.
> >
> > While at it, always select GPIOLIB so that we don't need to use #ifdef
> > guards.
> >
> > Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
> 
> Is there any input-related content in the driver after this or
> should the whole driver just be moved over to drivers/gpio
> and replace the old GPIO driver that you delete in patch
> 2?
> 

Hi,

Yes there is... The main usage for the device is to use it as a
matrix keypad. However, all the keys that are not used will be then
exposed through a gpiochip to be consumed for example by gpio-keys

- Nuno Sá