On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote:
> In mt6779_keypad_irq_handler(), we
> 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5
> 2. Use that hardware code to compute columns/rows for the standard
> keyboard matrix.
>
> According to the (non-public) datasheet, the
> map between the hardware code and the cols/rows is:
>
> |(0) |(1) |(2)
> ----*-----*-----*-----
> | | |
> |(9) |(10) |(11)
> ----*-----*-----*-----
> | | |
> |(18) |(19) |(20)
> ----*-----*-----*-----
> | | |
>
> This brings us to another formula:
> -> row = code / 9;
> -> col = code % 3;
What if there are more than 3 columns?
>
> Implement this mapping in bitnr_to_col_row() to fetch the
> correct input event from keypad->input_dev->keycode and report that
> back to userspace.
>
> Fixes: f28af984e771 ("Input: mt6779-keypad - add MediaTek keypad driver")
> Co-developed-by: Fabien Parent <fparent@xxxxxxxxxxxx>
> Signed-off-by: Fabien Parent <fparent@xxxxxxxxxxxx>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxxxx>
> ---
> drivers/input/keyboard/mt6779-keypad.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c
> index 2e7c9187c10f..23360de20da5 100644
> --- a/drivers/input/keyboard/mt6779-keypad.c
> +++ b/drivers/input/keyboard/mt6779-keypad.c
> @@ -36,6 +36,19 @@ static const struct regmap_config mt6779_keypad_regmap_cfg = {
> .max_register = 36,
> };
>
> +/*
> + * | hardware key code | col0 | col1 | col2|
> + * | ----------------- | -----| ---- | --- |
> + * | row0 | 0 | 1 | 2 |
> + * | row1 | 9 | 10 | 11 |
> + * | row2 | 18 | 19 | 20 |
> + */
> +static void bitnr_to_col_row(int bit_nr, int *col, int *row)
> +{
> + *row = bit_nr / 9;
> + *col = bit_nr % 3;
> +}
> +
> static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
> {
> struct mt6779_keypad *keypad = dev_id;
> @@ -61,8 +74,7 @@ static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
> if (bit_nr % 32 >= 16)
> continue;
>
> - row = bit_nr / 32;
> - col = bit_nr % 32;
> + bitnr_to_col_row(bit_nr, &col, &row);
> scancode = MATRIX_SCAN_CODE(row, col, row_shift);
> /* 1: not pressed, 0: pressed */
> pressed = !test_bit(bit_nr, new_state);
> --
> 2.32.0
>
--
Dmitry
