From aa0e26bb786b00eaa897e024769e299470815efe Mon Sep 17 00:00:00 2001 From: David Rivshin Date: Wed, 29 Mar 2017 00:14:16 -0700 Subject: [PATCH] Input: matrix_keypad - add option to drive inactive columns The gpio-matrix-keypad driver normally sets inactive columns as inputs while scanning. This does not work for all hardware, which may require the inactive columns to be actively driven in order to overcome any pull-ups/downs on the columns. Signed-off-by: David Rivshin Acked-by: Rob Herring Signed-off-by: Dmitry Torokhov --- .../bindings/input/gpio-matrix-keypad.txt | 2 ++ drivers/input/keyboard/matrix_keypad.c | 13 +++++++++---- include/linux/input/matrix_keypad.h | 3 +++ 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt index d0ea09ba249f..570dc10f0cd7 100644 --- a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt +++ b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt @@ -24,6 +24,8 @@ Optional Properties: - debounce-delay-ms: debounce interval in milliseconds - col-scan-delay-us: delay, measured in microseconds, that is needed before we can scan keypad after activating column gpio +- drive-inactive-cols: drive inactive columns during scan, + default is to turn inactive columns into inputs. Example: matrix-keypad { diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c index 18839cd5f76e..1f316d66e6f7 100644 --- a/drivers/input/keyboard/matrix_keypad.c +++ b/drivers/input/keyboard/matrix_keypad.c @@ -42,9 +42,10 @@ struct matrix_keypad { }; /* - * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause - * minmal side effect when scanning other columns, here it is configured to - * be input, and it should work on most platforms. + * NOTE: If drive_inactive_cols is false, then the GPIO has to be put into + * HiZ when de-activated to cause minmal side effect when scanning other + * columns. In that case it is configured here to be input, otherwise it is + * driven with the inactive value. */ static void __activate_col(const struct matrix_keypad_platform_data *pdata, int col, bool on) @@ -55,7 +56,8 @@ static void __activate_col(const struct matrix_keypad_platform_data *pdata, gpio_direction_output(pdata->col_gpios[col], level_on); } else { gpio_set_value_cansleep(pdata->col_gpios[col], !level_on); - gpio_direction_input(pdata->col_gpios[col]); + if (!pdata->drive_inactive_cols) + gpio_direction_input(pdata->col_gpios[col]); } } @@ -432,6 +434,9 @@ matrix_keypad_parse_dt(struct device *dev) if (of_get_property(np, "gpio-activelow", NULL)) pdata->active_low = true; + pdata->drive_inactive_cols = + of_property_read_bool(np, "drive-inactive-cols"); + of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms); of_property_read_u32(np, "col-scan-delay-us", &pdata->col_scan_delay_us); diff --git a/include/linux/input/matrix_keypad.h b/include/linux/input/matrix_keypad.h index 37b04a0fdea4..6174733a57eb 100644 --- a/include/linux/input/matrix_keypad.h +++ b/include/linux/input/matrix_keypad.h @@ -49,6 +49,8 @@ struct matrix_keymap_data { * @wakeup: controls whether the device should be set up as wakeup * source * @no_autorepeat: disable key autorepeat + * @drive_inactive_cols: drive inactive columns during scan, rather than + * making them inputs. * * This structure represents platform-specific data that use used by * matrix_keypad driver to perform proper initialization. @@ -73,6 +75,7 @@ struct matrix_keypad_platform_data { bool active_low; bool wakeup; bool no_autorepeat; + bool drive_inactive_cols; }; int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data, -- 2.20.1