Re: [PATCH v1 4/6] Input: mt6779-keypad - support double keys matrix

AngeloGioacchino Del Regno
2022-07-21T14:55:24Z

Il 21/07/22 16:51, Mattijs Korpershoek ha scritto:
> On Thu, Jul 21, 2022 at 10:34, AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> wrote:
>
>> Il 20/07/22 16:48, Mattijs Korpershoek ha scritto:
>>> MediaTek keypad has 2 modes of detecting key events:
>>> - single key: each (row, column) can detect one key
>>> - double key: each (row, column) is a group of 2 keys
>>>
>>> Double key support exists to minimize cost, since it reduces the number
>>> of pins required for physical keys.
>>>
>>> Double key is configured by setting BIT(0) of the KP_SEL register.
>>>
>>> Enable double key matrix support based on the mediatek,double-keys
>>> device tree property.
>>>
>>> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
>>> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
>>>
>>> diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c
>>> index bf447bf598fb..9a5dbd415dac 100644
>>> --- a/drivers/input/keyboard/mt6779-keypad.c
>>> +++ b/drivers/input/keyboard/mt6779-keypad.c
>>> @@ -18,6 +18,7 @@
>>> #define MTK_KPD_DEBOUNCE_MASK GENMASK(13, 0)
>>> #define MTK_KPD_DEBOUNCE_MAX_MS 256
>>> #define MTK_KPD_SEL 0x0020
>>> +#define MTK_KPD_SEL_DOUBLE_KP_MODE BIT(0)
>>> #define MTK_KPD_SEL_COL GENMASK(15, 10)
>>> #define MTK_KPD_SEL_ROW GENMASK(9, 4)
>>> #define MTK_KPD_SEL_COLMASK(c) GENMASK((c) + 9, 10)
>>> @@ -31,6 +32,7 @@ struct mt6779_keypad {
>>> struct clk *clk;
>>> u32 n_rows;
>>> u32 n_cols;
>>> + bool double_keys;
>>> DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
>>> };
>>>
>>> @@ -67,8 +69,13 @@ static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
>>> continue;
>>>
>>> key = bit_nr / 32 * 16 + bit_nr % 32;
>>> - row = key / 9;
>>> - col = key % 9;
>>> + if (keypad->double_keys) {
>>> + row = key / 13;
>>> + col = (key % 13) / 2;
>>> + } else {
>>> + row = key / 9;
>>> + col = key % 9;
>>> + }
>>
>> I don't fully like this if branch permanently evaluating true or false, as no
>> runtime can actually change this result...
>>
>> In practice, it's fine, but I was wondering if anyone would disagree with the
>> following proposal...
>>
>> struct mt6779_keypad {
>> .......
>> void (*calc_row_col)(unsigned int *row, unsigned int *col);
>> };
>>
>> In mt6779_keypad_irq_handler:
>>
>> key = bit_nr / 32 * 16 + bit_nr % 32;
>> keypad->calc_row_col(&row, &col);
>>
>> and below...
>>
>>>
>>> scancode = MATRIX_SCAN_CODE(row, col, row_shift);
>>> /* 1: not pressed, 0: pressed */
>>> @@ -150,6 +157,8 @@ static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
>>>
>>> wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
>>>
>>> + keypad->double_keys = device_property_read_bool(&pdev->dev, "mediatek,double-keys");
>>> +
>>> dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
>>> keypad->n_rows, keypad->n_cols, debounce);
>>>
>>> @@ -166,6 +175,10 @@ static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
>>> regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
>>> (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);
>>>
>>> + if (keypad->double_keys)
>>
>> keypad->calc_row_col = mt6779_keypad_calc_row_col_double_kp;
>>
>>> + regmap_update_bits(keypad->regmap, MTK_KPD_SEL,
>>> + MTK_KPD_SEL_DOUBLE_KP_MODE, MTK_KPD_SEL_DOUBLE_KP_MODE);
>>> +
>>
>> } else {
>> keypad->calc_row_col = mt6779_keypad_calc_row_col_single_kp;
>> }
>>
>>> regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_ROW,
>>> MTK_KPD_SEL_ROWMASK(keypad->n_rows));
>>> regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_COL,
>>
>> what do you think?
>
> Hi Angelo,
>
> Thank you for your detailed suggestion. I like it and since I have to
> resend a v2 anyways, I will consider implementing it.
> On the other hand, I'm a little reluctant because it means that I'll
> have to remove Matthias's reviewed-by :(
>

Yes, you will have to. In that case:

Matthias, any considerations about this idea? :)))

>>
>> Cheers,
>> Angelo