Re: CONFIG_KEYBOARD_GPIO for debian linux-image-rpi

[Pali Rohár <pali@kernel.org>]

On Saturday 15 July 2023 10:31:53 Salvatore Bonaccorso wrote:
> Hi,
> 
> Let's loop in the Debian kernel team.
> 
> On Fri, Jul 14, 2023 at 10:51:19PM +0200, Pali Rohár wrote:
> > Hello! I'm not sure who to ask about this issue but you are the last
> > person who modified linux-image-rpi debian package for bookworm.
> > 
> > I have done clean install of bookworm for raspberrypi (armel, rev1b) and
> > I figured out that kernel does not contain CONFIG_KEYBOARD_GPIO anymore.
> > 
> >   $ uname -a
> >   Linux raspberrypi 6.1.0-10-rpi #1 Debian 6.1.37-1 (2023-07-03) armv6l GNU/Linux
> > 
> >   $ grep CONFIG_KEYBOARD_GPIO /boot/config-6.1.0-10-rpi
> >   # CONFIG_KEYBOARD_GPIO is not set
> >   # CONFIG_KEYBOARD_GPIO_POLLED is not set
> > 
> > So any gpio based keyboard on raspberry pi does not work. Personally I'm
> > using shutdown gpio button and I read more forums that lot of other
> > people are using gpio button for shutdown action too. So I think that in
> > raspberrypi kernel specific package, this driver can be useful to have.
> > 
> > It there any reason why CONFIG_KEYBOARD_GPIO is disabled in bookworm
> > kernel from linux-image-rpi package? And if not, would it be possible to
> > enable this driver?
> 
> I do not think there is any special reason for that, and just might be
> enabled for the rpi specific config, let's see what our arm* porters
> say. And if nothing speaks about it we might top-down (in the upper
> suites first, then maybe down to bookworm) enable it.

Ok, thank you for information. Just to note that lot of 32-bit and
64-bit ARM boards also use CONFIG_KEYBOARD_GPIO (for example run
git grep gpio-keys arch/arm{,64}/boot/dts), so maybe also other
configurations than rpi can benefit from having this driver enabled.

I have looked at my another debian system running on 64-bit ARM and in
older bullseye's kernel linux-image-5.10.0-23-arm64 package there is
CONFIG_KEYBOARD_GPIO driver, see:

  $ grep CONFIG_KEYBOARD_GPIO /boot/config-5.10.0-23-arm64
  CONFIG_KEYBOARD_GPIO=m
  # CONFIG_KEYBOARD_GPIO_POLLED is not set

> > CONFIG_KEYBOARD_GPIO is tristate symbol, so if there is space problem,
> > it can be enabled as loadable module and it would be loaded ondemand
> > only when needed.
> 
> In case of yes to above question, it should be enabled as loadable
> module.
> 
> Thanks for raising it.
> 
> Regards,
> Salvatore