[PATCH v2 5/7] Input: mt6779-keypad - support double keys matrix

From: Mattijs Korpershoek
Date: Tue Jul 26 2022 - 08:56:57 EST


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,keys-per-group
device tree property.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxxxx>

diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c
index 39c931974bde..f70b02396de4 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)
@@ -102,12 +103,21 @@ static void mt6779_keypad_calc_row_col_single(unsigned int key,
*col = key % 9;
}

+static void mt6779_keypad_calc_row_col_double(unsigned int key,
+ unsigned int *row,
+ unsigned int *col)
+{
+ *row = key / 13;
+ *col = (key % 13) / 2;
+}
+
static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
{
struct mt6779_keypad *keypad;
void __iomem *base;
int irq;
u32 debounce;
+ u32 keys_per_group;
bool wakeup;
int error;

@@ -156,7 +166,20 @@ static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
return -EINVAL;
}

- keypad->calc_row_col = mt6779_keypad_calc_row_col_single;
+ if (device_property_read_u32(&pdev->dev, "mediatek,keys-per-group", &keys_per_group))
+ keys_per_group = 1;
+
+ switch (keys_per_group) {
+ case 1:
+ keypad->calc_row_col = mt6779_keypad_calc_row_col_single;
+ break;
+ case 2:
+ keypad->calc_row_col = mt6779_keypad_calc_row_col_double;
+ break;
+ default:
+ dev_err(&pdev->dev, "Invalid keys-per-group: %d\n", keys_per_group);
+ return -EINVAL;
+ }

wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");

@@ -176,6 +199,10 @@ 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 (keys_per_group == 2)
+ regmap_update_bits(keypad->regmap, MTK_KPD_SEL,
+ MTK_KPD_SEL_DOUBLE_KP_MODE, MTK_KPD_SEL_DOUBLE_KP_MODE);
+
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,

--
b4 0.10.0-dev-78725