User manual

Page | 58
Sets GPIOs 136, 137, 138 and 139 as M4 (GPIO mode) and IDIS (input not
allowed)
1） Driver Design;
The source file: leds-gpio.c is saved under
/linux-2.6.32-sbc8140/drivers/leds/;
Call platform_driver_register to register gpio_leds driver;
static struct platform_driver gpio_led_driver = {
.probe = gpio_led_probe,
.remove = __devexit_p(gpio_led_remove),
.driver = {
.name = "leds-gpio",
.owner = THIS_MODULE,
},
};
static int __init gpio_led_init(void)
{
int ret;
#ifdef CONFIG_LEDS_GPIO_PLATFORM
ret = platform_driver_register(&gpio_led_driver);
if (ret)
return ret;
#endif
#ifdef CONFIG_LEDS_GPIO_OF
ret =
of_register_platform_driver(&of_gpio_leds_driver);
#endif
#ifdef CONFIG_LEDS_GPIO_PLATFORM
if (ret)
platform_driver_unregister(&gpio_led_driver);
#endif
return ret;
}
static void __exit gpio_led_exit(void)
{
#ifdef CONFIG_LEDS_GPIO_PLATFORM