[PATCH v2 2/2] leds: trigger: gpio: Convert to use kstrtox()

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

sscanf() is a heavy one and moreover requires additional boundary checks.
Convert driver to use kstrtox() and replace kstrtoul() by kstrtobool()
in gpio_trig_inverted_store().

While here, check the desired brightness against maximum defined for
a certain LED.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
- check against max_brightness (Jacek)
 drivers/leds/trigger/ledtrig-gpio.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c
index dc64679b1a92..2d70c35588cb 100644
--- a/drivers/leds/trigger/ledtrig-gpio.c
+++ b/drivers/leds/trigger/ledtrig-gpio.c
@@ -60,10 +60,10 @@ static ssize_t gpio_trig_brightness_store(struct device *dev,
 	unsigned desired_brightness;
 	int ret;
 
-	ret = sscanf(buf, "%u", &desired_brightness);
-	if (ret < 1 || desired_brightness > 255) {
+	ret = kstrtouint(buf, 10, &desired_brightness);
+	if (ret || desired_brightness > gpio_data->led->max_brightness) {
 		dev_err(dev, "invalid value\n");
-		return -EINVAL;
+		return ret ? ret : -EINVAL;
 	}
 
 	gpio_data->desired_brightness = desired_brightness;
@@ -86,16 +86,13 @@ static ssize_t gpio_trig_inverted_store(struct device *dev,
 {
 	struct led_classdev *led = led_trigger_get_led(dev);
 	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
-	unsigned long inverted;
+	bool inverted;
 	int ret;
 
-	ret = kstrtoul(buf, 10, &inverted);
-	if (ret < 0)
+	ret = kstrtobool(buf, &inverted);
+	if (ret)
 		return ret;
 
-	if (inverted > 1)
-		return -EINVAL;
-
 	gpio_data->inverted = inverted;
 
 	/* After inverting, we need to update the LED. */
@@ -122,10 +119,10 @@ static ssize_t gpio_trig_gpio_store(struct device *dev,
 	unsigned gpio;
 	int ret;
 
-	ret = sscanf(buf, "%u", &gpio);
-	if (ret < 1) {
+	ret = kstrtouint(buf, 10, &gpio);
+	if (ret) {
 		dev_err(dev, "couldn't read gpio number\n");
-		return -EINVAL;
+		return ret;
 	}
 
 	if (gpio_data->gpio == gpio)
-- 
2.23.0.rc1