The MediaTek keypad has a total of 6 input rows and 6 input columns.
By default, rows/columns 0-2 are enabled.
This is controlled by the KP_SEL register:
- bits[9:4] control row selection
- bits[15:10] control column selection
Each bit enables the corresponding row/column number (e.g KP_SEL[4]
enables ROW0)
Depending on how the keypad is wired, this may result in wrong readings
of the keypad state.
Program the KP_SEL register to limit the key detection to n_rows,
n_cols we retrieve from the device tree.
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20220707075236.126631-3-mkorpershoek@baylibre.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
The MediaTek keypad has a set of bits representing keys,
from KEY0 to KEY77, arranged in 5 chunks of 15 bits split into 5 32-bit
registers.
In our implementation, we simply decided to use register number as row
and offset in the register as column when encoding our "matrix".
Because of this, we can have a 5x32 matrix which does not match the
hardware at all, which is confusing.
Change the row/column calculation to match the hardware.
Fixes: f28af984e7 ("Input: mt6779-keypad - add MediaTek keypad driver")
Co-developed-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20220707075236.126631-2-mkorpershoek@baylibre.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
