From: Linus Walleij <redacted>
Sent: Wednesday, August 31, 2022 2:24 PM
To: Sa, Nuno <Nuno.Sa@analog.com>
Cc: linux-input@vger.kernel.org; linux-gpio@vger.kernel.org;
devicetree@vger.kernel.org; Krzysztof Kozlowski
[off-list ref]; Hennerich, Michael
[off-list ref]; Bartosz Golaszewski
[off-list ref]; Andy Shevchenko [off-list ref];
Rob Herring [off-list ref]; Dmitry Torokhov
[off-list ref]
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 [off-list ref]
wrote:

quoted

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

quoted

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

quoted

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@analog.com>

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