自己写的第一个驱动LED（s5pc100处理器的）

头文件 #define LED_ON _IO('L',0) /*给ioctl函数用的*/ #define LED_OFF _IO('L',1) /*给ioctl函数用的*/ /*给write函数来实现时用的*/ struct led_action { int action; /*ON = LED_ON, OFF = LED_OFF*/ int nr; /*0 = LED1,1 = LED2,2 =LED3, 3 = LED4*/ }; 应用层序 #include #include #include #include #include "led.h" int main(int argc, const char *argv[]) { int fd; int i = 0; fd = open("/dev/led", O_RDWR); if(fd < 0) { perror("open"); exit(1); } while(1) { ioctl(fd, LED_ON, i); usleep(100000); ioctl(fd, LED_OFF, i); usleep(100000); i++; if(i == 4) i = 0; } return 0; } 驱动实现函数 #include #include #include #include #include #include #include #include #include "led.h" #define s5pc100_GPG3CON 0xe03001c0 #define s5pc100_GPG3DAT 0xe03001c4 dev_t devno; int led_major = 250; int led_minor = 0; int number_of_devices = 1; MODULE_LICENSE("GPL"); struct led_device { struct cdev cdev; void __iomem *gpg3con; void __iomem *gpg3dat; }; struct led_device *led_device; static int s5pc100_led_open(struct inode *inode,struct file *file) { return 0; } static int s5pc100_led_close(struct inode *inode,struct file *file) { return 0; } static int s5pc100_led_ioctl(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long arg) { switch(cmd) { case LED_ON: writel((readl(led_device->gpg3dat) & ~0xf)| 0x1 << arg,led_device->gpg3dat); break; case LED_OFF: writel(readl(led_device->gpg3dat) & ~(0x1 cdev,&led_fops); led_device->cdev.owner = THIS_MODULE; ret = cdev_add(&led_device->cdev,devno,number_of_devices); if(ret < 0) { printk(KERN_ERR "can't add led_device error = %d\n",ret); goto err2; } printk(KERN_INFO "device have done!\n"); /*映射IO*/ led_device->gpg3con = ioremap(s5pc100_GPG3CON,4); if(led_device->gpg3con == NULL) { ret = -ENOMEM; goto err3; } led_device->gpg3dat = ioremap(s5pc100_GPG3DAT,4); if(led_device->gpg3dat == NULL) { ret = -ENOMEM; goto err4; } /*初始化寄存器，设置io为输出模式，并让灯全亮*/ writel((readl(led_device->gpg3con) & ~0xffff)| 0x1111,led_device->gpg3con); writel(readl(led_device->gpg3dat) | 0xf,led_device->gpg3dat); printk(KERN_INFO "write ok!\n"); return 0; err4: iounmap(led_device->gpg3con); err3: cdev_del(&led_device->cdev); err2: kfree(led_device); err1: unregister_chrdev_region(devno,number_of_devices); return ret; } static void __exit s5pc100_led_exit(void) { iounmap(led_device->gpg3dat); iounmap(led_device->gpg3con); cdev_del(&led_device->cdev); kfree(led_device); unregister_chrdev_region(devno,number_of_devices); } module_init(s5pc100_led_init); module_exit(s5pc100_led_exit);