Hisi kernel state GPIO read and write operation example

Examples of kernel mode GPIO read and write operations:

Step 1 Register GPIO:

gpio_request(gpio_num,NULL);

Each group of gpio has 8 GPIO pins GPIO1_1 numbered as 1 8+1 = 9*

Step 2: Set the GPIO direction:

对于输入：gpio_direction_input(gpio_num)
对于输出：gpio_direction_output(gpio_num,gpio_out_val)
        gpio_out_val,输出的初始值，0或1

Step 3 View GPIO input value or set GPIO output value

 查看输入值：gpio_get_value(gpio_num);
 输出低：gpio_set_value(gpio_num,0);
 输出高：gpio_set_value(gpio_num,1);

Step 4: Release the registered GPIO number:

gpio_free(gpio_num);