[PATCH v3 4/4] Input: charlieplex_keypad: add GPIO charlieplex keypad

[Dmitry Torokhov]

On Wed, Feb 25, 2026 at 11:56:52AM -0500, Hugo Villeneuve wrote:
> On Wed, 25 Feb 2026 11:41:55 -0500
> Hugo Villeneuve <hugo at hugovil.com> wrote:
> 
> > Hi Andy,
> > thank you for the review.
> > 
> > On Wed, 25 Feb 2026 18:12:13 +0200
> > Andy Shevchenko <andriy.shevchenko at intel.com> wrote:
> > 
> > > On Wed, Feb 25, 2026 at 10:54:01AM -0500, Hugo Villeneuve wrote:
> > > 
> > > > Add support for GPIO-based charlieplex keypad, allowing to control
> > > > N^2-N keys using N GPIO lines.
> > > > 
> > > > Reuse matrix keypad keymap to simplify, even if there is no concept
> > > > of rows and columns in this type of keyboard.
> > > 
> > > ...
> > > 
> > > > +/*
> > > > + *  GPIO driven charlieplex keypad driver
> > > > + *
> > > > + *  Copyright (c) 2025 Hugo Villeneuve <hvilleneuve at dimonoff.com>
> > > > + *
> > > > + *  Based on matrix_keyboard.c
> > > 
> > > A single space after asterisk is enough.
> > 
> > Ok, leftover from copy/paste from matrix_keyboard.c :)
> > 
> > > 
> > > > + */
> > > 
> > > ...
> > > 
> > > + bitops.h
> > > 
> > > > +#include <linux/delay.h>
> > > 
> > > + dev_printk.h
> > > + device/devres.h
> > > + err.h
> > > 
> > > > +#include <linux/gpio/consumer.h>
> > > > +#include <linux/input.h>
> > > > +#include <linux/input/matrix_keypad.h>
> > > 
> > > + math.h
> > 
> > Ok.
> > 
> > 
> > > 
> > > > +#include <linux/module.h>
> > > 
> > > > +#include <linux/of.h>
> > > 
> > > Is this in use? Or you wanted mod_devicetable.h for OF ID table?
> > 
> > I need only OF ID table, so will replace with mod_devicetable.h.
> 
> Hi Andy,
> finally I need <linux/of.h> for of_match_ptr()...
> 
> But I will keep <mod_devicetable.h> ...

Do we need the dependency on OF? We may include of match pointer
unconditionally and the driver could be used on ACPI systems with
PRP0001 HID.

Thanks.

-- 
Dmitry