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>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c
index cd7dbb60f60f..b02c670ef01d 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 @@ static void gpio_extcon_work(struct work_struct *work)
                              work);
 
         state = gpio_get_value(data->gpio);
+        if (data->gpio_active_low)
+                state = !state;
         extcon_set_state(&data->edev, state);
 }
 
@@ -96,6 +99,7 @@ static int gpio_extcon_probe(struct platform_device *pdev)
 
         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)