[v3] input: add GPIO-based charlieplex keypad

[PATCH v3 0/4] input: add GPIO-based charlieplex keypad

Posted by Hugo Villeneuve 1 month, 1 week ago

From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

Hello,
this patch series add a new GPIO charlieplex keypad driver.

The first two patches simply commonize two properties that are present in
a few bindings, so that the actual patches for the charlieplex keypad driver
can reuse them instead of also redefining them.

I have tested the driver on a custom board with a Solidrun RZ/G2LC SOM
with three charlieplex keyboards, all connected thru a single PCA9416 I2C GPIO
expander.

Link: [v1] https://lore.kernel.org/all/20260203155023.536103-1-hugo@hugovil.com/
Link: [v2] https://lore.kernel.org/all/20260213171431.2228814-1-hugo@hugovil.com/

Changes for v3:
- Add ASCII diagram in bindings, and reference to it in example
- Reorder properties alphabetically
- Add patch to define common input settling-time-us property
- Add patch to define common input debounce-delay-ms property

Changes for v2:
- Fix yamllint error for example
- Remove unused debug variable (nkeys)
- Remove support for custom linux,no-autorepeat DT property
- Remove support for custom gpio-activelow DT property

Thank you.

Hugo Villeneuve (4):
  dt-bindings: input: add debounce-delay-ms common property
  dt-bindings: input: add settling-time-us common property
  dt-bindings: input: add GPIO charlieplex keypad
  Input: charlieplex_keypad: add GPIO charlieplex keypad

 .../bindings/auxdisplay/holtek,ht16k33.yaml   |   5 +-
 .../bindings/input/cirrus,ep9307-keypad.yaml  |   7 +-
 .../input/gpio-charlieplex-keypad.yaml        | 106 +++++++++
 .../bindings/input/gpio-matrix-keypad.yaml    |   5 +-
 .../devicetree/bindings/input/input.yaml      |  16 ++
 .../input/mediatek,mt6779-keypad.yaml         |   1 +
 .../devicetree/bindings/mfd/fsl,mc13xxx.yaml  |   2 -
 MAINTAINERS                                   |   7 +
 drivers/input/keyboard/Kconfig                |  14 ++
 drivers/input/keyboard/Makefile               |   1 +
 drivers/input/keyboard/charlieplex_keypad.c   | 213 ++++++++++++++++++
 11 files changed, 365 insertions(+), 12 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/gpio-charlieplex-keypad.yaml
 create mode 100644 drivers/input/keyboard/charlieplex_keypad.c


base-commit: ab2e361ca97a42b7af8be1d273646b30d3b75bf3
-- 
2.47.3

Re: [PATCH v3 0/4] input: add GPIO-based charlieplex keypad

Posted by Geert Uytterhoeven 1 month, 1 week ago

Hi Hugo,

Thanks for your series!

On Wed, 25 Feb 2026 at 16:54, Hugo Villeneuve <hugo@hugovil.com> wrote:
> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
>
> Hello,
> this patch series add a new GPIO charlieplex keypad driver.
>
> The first two patches simply commonize two properties that are present in
> a few bindings, so that the actual patches for the charlieplex keypad driver
> can reuse them instead of also redefining them.
>
> I have tested the driver on a custom board with a Solidrun RZ/G2LC SOM
> with three charlieplex keyboards, all connected thru a single PCA9416 I2C GPIO

PCA9416? The closest I could find is TCA9416, which is something
different.

> expander.
>
> Link: [v1] https://lore.kernel.org/all/20260203155023.536103-1-hugo@hugovil.com/
> Link: [v2] https://lore.kernel.org/all/20260213171431.2228814-1-hugo@hugovil.com/

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v3 0/4] input: add GPIO-based charlieplex keypad

Posted by Hugo Villeneuve 1 month, 1 week ago

Hi Geert,

On Thu, 26 Feb 2026 10:20:33 +0100
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> Hi Hugo,
> 
> Thanks for your series!
> 
> On Wed, 25 Feb 2026 at 16:54, Hugo Villeneuve <hugo@hugovil.com> wrote:
> > From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> >
> > Hello,
> > this patch series add a new GPIO charlieplex keypad driver.
> >
> > The first two patches simply commonize two properties that are present in
> > a few bindings, so that the actual patches for the charlieplex keypad driver
> > can reuse them instead of also redefining them.
> >
> > I have tested the driver on a custom board with a Solidrun RZ/G2LC SOM
> > with three charlieplex keyboards, all connected thru a single PCA9416 I2C GPIO
> 
> PCA9416? The closest I could find is TCA9416, which is something
> different.

Its a typo, it is PCA6416, thanks for catching that!

Hugo.


> 
> > expander.
> >
> > Link: [v1] https://lore.kernel.org/all/20260203155023.536103-1-hugo@hugovil.com/
> > Link: [v2] https://lore.kernel.org/all/20260213171431.2228814-1-hugo@hugovil.com/
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
> 


-- 
Hugo Villeneuve