Matrix_keypad with high capacity need a longer settle time after enable
all columns and re-enabling interrupts.
This to give time stable the system and not generate interrupts.
Add a new optional device-tree property to configure the time before
enabling interrupts after disable all columns.
The default is no delay.
Signed-off-by: Markus Burri <markus.burri@xxxxxx>
---
drivers/input/keyboard/matrix_keypad.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c
index 2818915..46873b8 100644
--- a/drivers/input/keyboard/matrix_keypad.c
+++ b/drivers/input/keyboard/matrix_keypad.c
@@ -27,6 +27,7 @@ struct matrix_keypad {
unsigned int row_shift;
unsigned int col_scan_delay_us;
+ unsigned int all_cols_on_delay_us;
/* key debounce interval in milli-second */
unsigned int debounce_ms;
bool drive_inactive_cols;
@@ -78,6 +79,9 @@ static void activate_all_cols(struct matrix_keypad *keypad, bool on)
for (col = 0; col < keypad->num_col_gpios; col++)
__activate_col(keypad, col, on);
+
+ if (on && keypad->all_cols_on_delay_us)
+ fsleep(keypad->all_cols_on_delay_us);
}
static bool row_asserted(struct matrix_keypad *keypad, int row)
@@ -403,6 +407,8 @@ static int matrix_keypad_probe(struct platform_device *pdev)
&keypad->debounce_ms);
device_property_read_u32(&pdev->dev, "col-scan-delay-us",
&keypad->col_scan_delay_us);
+ device_property_read_u32(&pdev->dev, "all-cols-on-delay-us",
+ &keypad->all_cols_on_delay_us);
err = matrix_keypad_init_gpio(pdev, keypad);
if (err)
--
2.39.5
