From 90a0a63451e42e3638039dde2e511e95a8486880 Mon Sep 17 00:00:00 2001 From: Markus Burri Date: Tue, 25 Feb 2025 09:59:07 -0800 Subject: [PATCH] Input: matrix_keypad - add settle time after enabling all columns Matrix keypads with high capacity need a longer settle time after enabling all columns before re-enabling interrupts. The delay gives the system time to settle and avoids spurious interrupts. Add a new optional device property to configure the delay after enabling all columns. The default is no delay. Signed-off-by: Markus Burri Reviewed-by: Manuel Traut Link: https://lore.kernel.org/r/20250110054906.354296-7-markus.burri@mt.com Signed-off-by: Dmitry Torokhov --- 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 2a3b3bfc2878..889505e59f85 100644 --- a/drivers/input/keyboard/matrix_keypad.c +++ b/drivers/input/keyboard/matrix_keypad.c @@ -26,6 +26,7 @@ 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; @@ -77,6 +78,9 @@ 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) @@ -392,6 +396,8 @@ 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) -- 2.50.1