If the device is a detachable, we may still probe this device because there are some button switches, e.g. volume buttons and power buttons, registered by this driver. Let's allow the device node to be missing row and column device properties to indicate that the keyboard matrix shouldn't be registered. This removes an input device on Trogdor devices such as Wormdingler that don't have a matrix keyboard, but still have power and volume buttons. That helps userspace understand there isn't a keyboard present when the detachable keyboard is disconnected. Cc: Benson Leung <bleung@xxxxxxxxxxxx> Cc: Guenter Roeck <groeck@xxxxxxxxxxxx> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx> Cc: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> --- I tried to use mkbp info to query the number of rows and columns, but my EC firmware doesn't have commit 8505881ed0b9 ("mkbp: Separate MKBP_INFO host command from the keyboard driver") so it always returns 8 and 13 for the rows and columns. Sigh. With updated firmware we could query it, or we could rely on DT like we do already. Originally I was setting the properties to 0, but matrix_keypad_parse_properties() spits out an error message in that case and so it seems better to delete the properties and check for their existence instead. Another alternative would be to change the compatible to be "google,cros-ec-keyb-switches" or something that indicates there are only switches and no matrix keyboard. drivers/input/keyboard/cros_ec_keyb.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c index 6534dfca60b4..ac9a953bff02 100644 --- a/drivers/input/keyboard/cros_ec_keyb.c +++ b/drivers/input/keyboard/cros_ec_keyb.c @@ -537,6 +537,15 @@ static int cros_ec_keyb_register_matrix(struct cros_ec_keyb *ckdev) u32 key_pos; unsigned int row, col, scancode, n_physmap; + /* + * 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_read_bool(dev, "keypad,num-rows") && + !device_property_read_bool(dev, "keypad,num-cols")) + return 0; + err = matrix_keypad_parse_properties(dev, &ckdev->rows, &ckdev->cols); if (err) return err; -- https://chromeos.dev