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-rw-r--r--Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt2
-rw-r--r--drivers/input/keyboard/matrix_keypad.c13
-rw-r--r--include/linux/input/matrix_keypad.h3
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,