s3c6410字符设备（一）led字符驱动与测试程序

来源：互联网发布：银泰证券软件下载编辑：程序博客网时间：2024/05/16 17:45

在前面gpio编程中已经写过led灯控制程序，那么现在写字符设备将变得简单许多，而且有更高级的函数让我们调用。

1.测试程序

#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <sys/ioctl.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>int main(int argc, char **argv){        int on;        int led_no;        int fd;        if (argc != 3 || sscanf(argv[1], "%d", &led_no) != 1 || sscanf(argv[2],"%d", &on) != 1 ||                        on < 0 || on > 1 || led_no < 0 || led_no > 3) {                fprintf(stderr, "Usage: leds led_no 0|1\n");                exit(1);        }        fd = open("/dev/leds0", 0); //打开设备文件        if (fd < 0) {                fd = open("/dev/leds", 0);        }        if (fd < 0) {                perror("open device leds");                exit(1);        }        ioctl(fd, on, led_no); //使用ioctl控制led        close(fd);        return 0;}

2.驱动程序

#include <linux/miscdevice.h>#include <linux/delay.h>#include <asm/irq.h>//#include <mach/regs-gpio.h>#include <mach/hardware.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/init.h>#include <linux/mm.h>#include <linux/fs.h>#include <linux/types.h>#include <linux/delay.h>#include <linux/moduleparam.h>#include <linux/slab.h>#include <linux/errno.h>#include <linux/ioctl.h>#include <linux/cdev.h>#include <linux/string.h>#include <linux/list.h>#include <linux/pci.h>#include <asm/uaccess.h>#include <asm/atomic.h>#include <asm/unistd.h>#include <mach/map.h>#include <mach/regs-clock.h>#include <mach/regs-gpio.h>#include <plat/gpio-cfg.h>#include <mach/gpio-bank-e.h>#include <mach/gpio-bank-k.h>#define DEVICE_NAME "leds"static long sbc2440_leds_ioctl(struct file *filp, unsigned int cmd, unsigned long arg){switch(cmd) {unsigned tmp;case 0:case 1:if (arg > 4) {return -EINVAL;}tmp = readl(S3C64XX_GPKDAT); //从内存映射的i/o空间读取32位数据tmp &= ~(1 << (4 + arg));tmp |= ( (!cmd) << (4 + arg) );writel(tmp, S3C64XX_GPKDAT); //向i/o地址写入32位数据//printk (DEVICE_NAME": %d %d\n", arg, cmd);return 0;default:return -EINVAL;}}static struct file_operations dev_fops = {.owner= THIS_MODULE,.unlocked_ioctl= sbc2440_leds_ioctl,};static struct miscdevice misc = {.minor = MISC_DYNAMIC_MINOR,.name = DEVICE_NAME,.fops = &dev_fops,};static int __init dev_init(void){int ret;{unsigned tmp;tmp = readl(S3C64XX_GPKCON);tmp = (tmp & ~(0xffffU<<16))|(0x1111U<<16);writel(tmp, S3C64XX_GPKCON); //初始化控制寄存器tmp = readl(S3C64XX_GPKDAT);tmp |= (0xF << 4);writel(tmp, S3C64XX_GPKDAT); //初始化数据寄存器}ret = misc_register(&misc); //注册主设备号为10的特殊字符设备printk (DEVICE_NAME"\tinitialized\n");return ret;}static void __exit dev_exit(void){misc_deregister(&misc);}module_init(dev_init);module_exit(dev_exit);MODULE_LICENSE("GPL");MODULE_AUTHOR("FriendlyARM Inc.");