[PATCH 2/2] ledtrig-gpio: 0 is a valid GPIO number

[Kun Yi]

GPIO number 0 is a valid case to handle. Use -1 as initial value
and use gpio_is_valid() to determine validity of the GPIO
number.

Signed-off-by: Kun Yi <ku...@google.com>
Change-Id: I4a29f98b237fd0d8ba4dd2a28219d4429f2ccfff
---
 drivers/leds/trigger/ledtrig-gpio.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/leds/trigger/ledtrig-gpio.c 
b/drivers/leds/trigger/ledtrig-gpio.c
index f6d50e031492..48d8ef8538bd 100644
--- a/drivers/leds/trigger/ledtrig-gpio.c
+++ b/drivers/leds/trigger/ledtrig-gpio.c
@@ -22,7 +22,7 @@ struct gpio_trig_data {
 
        unsigned desired_brightness;    /* desired brightness when led is on */
        unsigned inverted;              /* true when gpio is inverted */
-       unsigned gpio;                  /* gpio that triggers the leds */
+       int gpio;                       /* gpio that triggers the leds */
 };
 
 static irqreturn_t gpio_trig_irq(int irq, void *_led)
@@ -114,13 +114,12 @@ static ssize_t gpio_trig_gpio_show(struct device *dev,
 {
        struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
 
-       return sprintf(buf, "%u\n", gpio_data->gpio);
+       return sprintf(buf, "%d\n", gpio_data->gpio);
 }
 
-static inline void free_used_gpio_if_valid(unsigned int gpio,
-                                          struct led_classdev *led)
+static inline void free_used_gpio_if_valid(int gpio, struct led_classdev *led)
 {
-       if (gpio == 0)
+       if (!gpio_is_valid(gpio))
                return;
 
        free_irq(gpio_to_irq(gpio), led);
@@ -144,12 +143,6 @@ static ssize_t gpio_trig_gpio_store(struct device *dev,
        if (gpio_data->gpio == gpio)
                return n;
 
-       if (!gpio) {
-               free_used_gpio_if_valid(gpio_data->gpio, led);
-               gpio_data->gpio = 0;
-               return n;
-       }
-
        ret = gpio_request(gpio, "ledtrig-gpio");
        if (ret) {
                dev_err(dev, "gpio_request failed with error %d\n", ret);
@@ -195,6 +188,7 @@ static int gpio_trig_activate(struct led_classdev *led)
                return -ENOMEM;
 
        gpio_data->led = led;
+       gpio_data->gpio = -1;
        led_set_trigger_data(led, gpio_data);
 
        return 0;
-- 
2.21.0.1020.gf2820cf01a-goog