驱动代码：
#include <linux/init.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/miscdevice.h> #include <linux/fs.h> #include <linux/gpio.h> #include <plat/gpio-cfg.h> #include <mach/gpio.h> #include <mach/gpio-exynos4.h> MODULE_LICENSE("GPL"); //设备节点 #define NODE_NAME "leds_node" static int leds_open(struct inode *node, struct file *fp) { printk("leds open.\n"); return 0; } static int leds_release(struct inode *node, struct file *fp) { printk("leds release.\n"); return 0; } static int leds_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) { printk("leds ioctl, cmd: %d, arg: %d\n", cmd, arg); switch (cmd) { case 0: gpio_direction_output(EXYNOS4_GPL2(0), arg); break; default: break; } return 0; } struct file_operations leds_ops = { .owner = THIS_MODULE, .open = leds_open, .release = leds_release, .unlocked_ioctl = leds_ioctl, }; struct miscdevice leds_misc_dev = { .minor = MISC_DYNAMIC_MINOR, //自动分配次设备号 .name = NODE_NAME, .fops = &leds_ops, }; static int leds_probe(struct platform_device *dev) { printk("leds probe, device name: %s\n", dev->name); int ret = gpio_request(EXYNOS4_GPL2(0), "LEDS"); if (ret) { printk("gpio request gpl0(2) failed.\n"); return -1; } //gpio_direction_output(EXYNOS4_GPL2(0), 1); s3c_gpio_cfgpin(EXYNOS4_GPL2(0), GPIO_OUTPUT); misc_register(&leds_misc_dev); return 0; } static int leds_remove(struct platform_device *dev) { printk("leds remove, device name: %s\n", dev->name); gpio_free(EXYNOS4_GPL2(0)); misc_deregister(&leds_misc_dev); return 0; } struct platform_driver leds_driver = { .probe = leds_probe, .remove = leds_remove, .driver = { .name = "leds_ctl", .owner = THIS_MODULE, } }; struct platform_device leds_dev = { .name = "leds_ctl", .id = -1, }; static int leds_init() { printk(KERN_EMERG "leds init.\n"); platform_device_register(&leds_dev); platform_driver_register(&leds_driver); return 0; } static void leds_exit() { printk(KERN_EMERG "leds exit.\n"); platform_driver_unregister(&leds_driver); platform_device_unregister(&leds_dev); } module_init(leds_init); module_exit(leds_exit);应用代码：
#include <stdio.h> //printf() #include <stdlib.h> //exit() #include <string.h> //strlen(), bzero(); #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> int main(int argc, char *argv[]) { int fd = open("/dev/leds_node", O_RDWR | O_NDELAY); while (1) { ioctl(fd, 0, 1); sleep(1); ioctl(fd, 0, 0); sleep(1); } close(fd); return 0; }