获取设备树中GPIO的第三个参数

1 imx6-led{
2         compatible = "imx6,led";
3         led-green = <&gpio1 8 GPIO_ACTIVE_LOW>;
4         status = "okay";
5     };

 1 #include <linux/of.h>
 2 #include <linux/of_gpio.h>
 3
 4
 5  
 6 static int imx6_led_probe(struct platform_device *pdev)
 7 {   int gpio, flag;
 8     struct device_node *led_node = pdev->dev.of_node;
 9  
10     gpio = of_get_named_gpio_flags(led_node, "led-green", 0, &flag);
11     if (!gpio_is_valid(gpio)){
12         printk("invalid led-green: %d\n",gpio);
13         return -1;
14     } 
15     if (gpio_request(gpio, "led_green")) {
16         printk("gpio %d request failed!\n",gpio);
17         return ret;
18     }
19     gpio_direction_output(gpio, flag);//flag 即第三个参数“GPIO_ACTIVE_LOW”
20 　　////////xxxxxxxxxx
21　　 ////////xxxxxxxxxx
22
23 }