| Message ID | 20220503042242.3597561-3-swboyd@chromium.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Input: cros-ec-keyb: Better matrixless support | expand |
Hi, On Mon, May 2, 2022 at 9:22 PM Stephen Boyd <swboyd@chromium.org> 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@kernel.org> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: <devicetree@vger.kernel.org> > Cc: Benson Leung <bleung@chromium.org> > Cc: Guenter Roeck <groeck@chromium.org> > Cc: Douglas Anderson <dianders@chromium.org> > Cc: Hsin-Yi Wang <hsinyi@chromium.org> > Cc: "Joseph S. Barrera III" <joebar@chromium.org> > Fixes: 4352e23a7ff2 ("Input: cros-ec-keyb - only register keyboard if rows/columns exist") > Signed-off-by: Stephen Boyd <swboyd@chromium.org> > --- > 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@chromium.org>
Quoting Doug Anderson (2022-05-03 08:09:11) > On Mon, May 2, 2022 at 9:22 PM Stephen Boyd <swboyd@chromium.org> wrote: > > > > 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? Yes, the idea is to make it more obvious to the point that the comment isn't needed. I'll change it to 'has_keyboard' and then drop the comment! > > In any case, I'm happy either way: > > Reviewed-by: Douglas Anderson <dianders@chromium.org>
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; err = matrix_keypad_parse_properties(dev, &ckdev->rows, &ckdev->cols); @@ -718,8 +715,13 @@ static int cros_ec_keyb_remove(struct platform_device *pdev) #ifdef CONFIG_OF static const struct of_device_id cros_ec_keyb_of_match[] = { - { .compatible = "google,cros-ec-keyb" }, - {}, + { + /* Must be first */ + .compatible = "google,cros-ec-keyb", + .data = (void *)true + }, + { .compatible = "google,cros-ec-keyb-switches" }, + {} }; MODULE_DEVICE_TABLE(of, cros_ec_keyb_of_match); #endif
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@kernel.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: <devicetree@vger.kernel.org> Cc: Benson Leung <bleung@chromium.org> Cc: Guenter Roeck <groeck@chromium.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Hsin-Yi Wang <hsinyi@chromium.org> Cc: "Joseph S. Barrera III" <joebar@chromium.org> Fixes: 4352e23a7ff2 ("Input: cros-ec-keyb - only register keyboard if rows/columns exist") Signed-off-by: Stephen Boyd <swboyd@chromium.org> --- drivers/input/keyboard/cros_ec_keyb.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)