Hi,
On Mon, May 2, 2022 at 9:22 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:
>
> In commit 4352e23a7ff2 ("Input: cros-ec-keyb - only register keyboard if
> rows/columns exist") we skipped registration of the keyboard if the
> row/columns property didn't exist, but that has a slight problem for
> existing DTBs. The DTBs have the rows/columns properties, so removing
> the properties to indicate only switches exist makes this keyboard
> driver fail to probe, resulting in broken power and volume buttons. Ease
> the migration of existing DTBs by skipping keyboard registration if the
> google,cros-ec-keyb-switches compatible exists.
>
> The end result is that new DTBs can either choose to remove the matrix
> keymap properties or leave them in place and add this new compatible
> indicating the matrix keyboard properties should be ignored. Existing
> DTBs will continue to work, but they will keep registering the keyboard
> that does nothing. To fix that problem we can add this extra compatible
> to existing devicetrees and the keyboard will stop being registered.
> Finally, if google,cros-ec-keyb is missing then this driver won't even
> attempt to register the matrix keyboard. Of course, this driver won't
> probe until this patch is applied in that scenario, but that's OK. This
> last case is likely only going to be used by new devicetrees created
> after this commit.
>
> Cc: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: <devicetree@xxxxxxxxxxxxxxx>
> Cc: Benson Leung <bleung@xxxxxxxxxxxx>
> Cc: Guenter Roeck <groeck@xxxxxxxxxxxx>
> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Cc: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> Cc: "Joseph S. Barrera III" <joebar@xxxxxxxxxxxx>
> Fixes: 4352e23a7ff2 ("Input: cros-ec-keyb - only register keyboard if rows/columns exist")
> Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> ---
> drivers/input/keyboard/cros_ec_keyb.c | 20 +++++++++++---------
> 1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
> index eef909e52e23..04c550aaf897 100644
> --- a/drivers/input/keyboard/cros_ec_keyb.c
> +++ b/drivers/input/keyboard/cros_ec_keyb.c
> @@ -536,14 +536,11 @@ static int cros_ec_keyb_register_matrix(struct cros_ec_keyb *ckdev)
> u32 *physmap;
> u32 key_pos;
> unsigned int row, col, scancode, n_physmap;
> + bool register_keyboard;
>
> - /*
> - * No rows and columns? There isn't a matrix but maybe there are
> - * switches to register in cros_ec_keyb_register_bs() because
> - * this is a detachable device.
> - */
> - if (!device_property_present(dev, "keypad,num-rows") &&
> - !device_property_present(dev, "keypad,num-cols"))
> + /* Skip matrix registration if no keyboard */
> + register_keyboard = device_get_match_data(dev);
> + if (!register_keyboard)
> return 0;
I'm a little on the fence about the local variable. It could have been
shorter as:
/* Skip matrix registration if no keyboard */
if (!device_get_match_data(dev))
...but I guess the "register_keyboard" maybe makes it more a little
more obvious?
In any case, I'm happy either way:
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
