extcon: gpio: Add support for active-low presence to detect pins
This patch add 'gpio_active_low' field to 'struct gpio_extcon_data'
to check whether gpio active state is 1(high) or 0(low).
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c
index cd7dbb6..b02c670e 100644
--- a/drivers/extcon/extcon-gpio.c
+++ b/drivers/extcon/extcon-gpio.c
@@ -34,6 +34,7 @@
struct gpio_extcon_data {
struct extcon_dev edev;
unsigned gpio;
+ bool gpio_active_low;
const char *state_on;
const char *state_off;
int irq;
@@ -49,6 +50,8 @@
work);
state = gpio_get_value(data->gpio);
+ if (data->gpio_active_low)
+ state = !state;
extcon_set_state(&data->edev, state);
}
@@ -96,6 +99,7 @@
extcon_data->edev.name = pdata->name;
extcon_data->gpio = pdata->gpio;
+ extcon_data->gpio_active_low = pdata->gpio_active_low;
extcon_data->state_on = pdata->state_on;
extcon_data->state_off = pdata->state_off;
if (pdata->state_on && pdata->state_off)
diff --git a/include/linux/extcon/extcon-gpio.h b/include/linux/extcon/extcon-gpio.h
index 4ce1aa7..4195810 100644
--- a/include/linux/extcon/extcon-gpio.h
+++ b/include/linux/extcon/extcon-gpio.h
@@ -27,6 +27,9 @@
* struct gpio_extcon_platform_data - A simple GPIO-controlled extcon device.
* @name: The name of this GPIO extcon device.
* @gpio: Corresponding GPIO.
+ * @gpio_active_low: Boolean describing whether gpio active state is 1 or 0
+ * If true, low state of gpio means active.
+ * If false, high state of gpio means active.
* @debounce: Debounce time for GPIO IRQ in ms.
* @irq_flags: IRQ Flags (e.g., IRQF_TRIGGER_LOW).
* @state_on: print_state is overriden with state_on if attached.
@@ -41,6 +44,7 @@
struct gpio_extcon_platform_data {
const char *name;
unsigned gpio;
+ bool gpio_active_low;
unsigned long debounce;
unsigned long irq_flags;
