#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>//定义并初始化LED设备的相关资源
static struct resource led_resource =
{.start = 0xE0200240,.end = 0xE0200240 + 8 - 1,.flags = IORESOURCE_MEM,
};//定义并初始化LED设备信息
static struct platform_device led_dev =
{.name = "led",             //设备名称.id = -1,                  //设备数量，-1表示只有一个设备.num_resources = 1,        //资源数量.resource = &led_resource, //资源指针.dev = {.release = led_release,},
};//注册LED设备
static int __init led_device_init(void)
{return platform_device_register(&led_dev);
}//注销LED设备
static void __exit led_device_exit(void)
{platform_device_unregister(&led_dev);
}module_init(led_device_init);
module_exit(led_device_exit);MODULE_AUTHOR("Lin");
MODULE_DESCRIPTION("led device for x210");
MODULE_LICENSE("GPL");

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <linux/leds.h>
#include <asm/uaccess.h>
#include <linux/cdev.h>
#include <linux/kdev_t.h>
#include <linux/ioctl.h>#define LED_IOC_MAGIC  'l'                　　//ioctl幻数
#define LED_IOC_MAXNR    2                　　//ioctl最大命令序数
#define    LED_ON    _IO(LED_IOC_MAGIC, 0)   //ioctl自定义命令
#define    LED_OFF    _IO(LED_IOC_MAGIC, 1)#define DEVNAME "led"        //设备名称static int led_major = 0;    //主设备号
static int led_minor = 0;    //次设备号
const  int led_count = 1;    //次设备数量//GPIO寄存器变量定义
typedef struct GPJ0REG
{volatile unsigned int gpj0con;volatile unsigned int gpj0dat;
}gpj0_reg_t;static gpj0_reg_t *pGPIOREG = NULL;static dev_t led_devnum;                 //设备号
static struct cdev *led_cdev = NULL;     //设备对象static struct class *led_cls = NULL;     //设备类
static struct device *led_dev = NULL;    //设备//LED设备的ioctl函数实现
static int led_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
{int reg_value = 0;//检测命令的有效性if (_IOC_TYPE(cmd) != LED_IOC_MAGIC) return -EINVAL;if (_IOC_NR(cmd) > LED_IOC_MAXNR) return -EINVAL;//根据命令，执行相应的硬件操作switch(cmd) {case LED_ON:reg_value = readl(&pGPIOREG->gpj0dat); reg_value &= ~((1 << 3) | (1 << 4) | (1 << 5));writel(&pGPIOREG->gpj0dat, reg_value);break;case LED_OFF:reg_value = readl(&pGPIOREG->gpj0dat); reg_value |= (1 << 3) | (1 << 4) | (1 << 5);writel(&pGPIOREG->gpj0dat, reg_value);break;default:  return -EINVAL;}return 0;
}static int led_open(struct inode *inode, struct file *filp)
{return 0;
}static int led_release(struct inode *inode, struct file *filp)
{return 0;
}//LED设备的write函数实现
static ssize_t led_write(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos)
{char kbuf[20] = {0};int reg_value = 0;memset(kbuf, 0, sizeof(kbuf));if (copy_from_user(kbuf, user_buf, count)){return -EFAULT;}if (kbuf[0] == '0'){reg_value = readl(&(pGPIOREG->gpj0dat)); reg_value |= (1 << 3) | (1 << 4) | (1 << 5);writel(reg_value, &(pGPIOREG->gpj0dat));}else{reg_value = readl(&(pGPIOREG->gpj0dat));  reg_value &= ~((1 << 3) | (1 << 4) | (1 << 5));writel(reg_value, &(pGPIOREG->gpj0dat));}return 1;
}//定义并初始化LED设备的操作集
static const struct file_operations led_ops =
{.owner      = THIS_MODULE,.open       = led_open,.write      = led_write,.ioctl      = led_ioctl,.release    = led_release,
};//LED设备的probe函数实现
static int led_probe(struct platform_device *pdev)
{struct resource *res_led = NULL;int ret = -1;int reg_value = 0;int i = 0;/****************************申请资源*******************************///获取资源res_led = platform_get_resource(pdev, IORESOURCE_MEM, 0);if (!res_led) {return -ENOMEM;}//动态内存映射if (!request_mem_region(res_led->start, resource_size(res_led), "GPIOJ0")){return -EBUSY;}pGPIOREG = ioremap(res_led->start, resource_size(res_led));if (pGPIOREG ==  NULL) {ret = -ENOENT;goto ERR_STEP;}/****************************初始化资源*******************************///设置GPIO为输出模式reg_value = readl(&(pGPIOREG->gpj0con)); reg_value |= (1 << (3*4)) | (1 << (4*4)) | (1 << (5*4));writel(reg_value, &(pGPIOREG->gpj0con));/***************************创建接口（cdev）***************************///申请cdev内存led_cdev = cdev_alloc();if (led_cdev == NULL){ret = -ENOMEM;goto ERR_STEP1;}//初始化led_cdev(将led_cdev于led_ops关联)cdev_init(led_cdev, &led_ops);//申请设备号ret = alloc_chrdev_region(&led_devnum, led_minor, led_count, DEVNAME);if (ret < 0){goto ERR_STEP1;}//注册LED设备对象(将cdev添加至系统字符设备链表中)ret = cdev_add(led_cdev, led_devnum, led_count);if (ret < 0){goto ERR_STEP2;}//创建设备类led_cls = class_create(THIS_MODULE, DEVNAME);if (IS_ERR(led_cls)) {ret = PTR_ERR(led_cls);goto ERR_STEP3;}//在设备类下创建设备文件led_major = MAJOR(led_devnum);for(i = led_minor; i < (led_count + led_minor); i++){led_dev = device_create(led_cls, NULL, MKDEV(led_major, i), NULL, "%s%d", DEVNAME, i);if(IS_ERR(led_dev)){ret = PTR_ERR(led_dev);goto ERR_STEP4;}}return 0;/*******************************倒映式错误处理*******************************/
ERR_STEP4:for(--i; i >= led_minor; i--){device_destroy(led_cls, MKDEV(led_major, i));}class_destroy(led_cls);ERR_STEP3:cdev_del(led_cdev);ERR_STEP2:unregister_chrdev_region(led_devnum, led_count);ERR_STEP1:iounmap(pGPIOREG);    ERR_STEP:release_mem_region(res_led->start, resource_size(res_led));return ret;
}int led_remove(struct platform_device *pdev)
{int i = 0;//删除设备文件for(i = led_minor; i < (led_count + led_minor); i++){device_destroy(led_cls, MKDEV(led_major, i));}//删除设备类
    class_destroy(led_cls);//删除设备对象
    cdev_del(led_cdev);//注销设备号
    unregister_chrdev_region(led_devnum, led_count);//释放内存
    iounmap(pGPIOREG);return 0;
}//定义并初始化LED驱动信息
static struct platform_driver led_drv =
{.driver = {.name  = "led",.owner = THIS_MODULE,},.probe = led_probe,.remove = led_remove,
};//注册LED驱动
static int __init led_driver_init(void)
{return platform_driver_register(&led_drv);
}//注销LED驱动
static void __exit led_driver_exit(void)
{platform_driver_unregister(&led_drv);
}module_init(led_driver_init);
module_exit(led_driver_exit);MODULE_AUTHOR("Lin");
MODULE_DESCRIPTION("led driver for x210");
MODULE_LICENSE("GPL");

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>#define    FILE_NAME    "/dev/led0"#define    LED_ON    _IO(LED_IOC_MAGIC, 0)
#define    LED_OFF    _IO(LED_IOC_MAGIC, 1)char WriteBuf[30];
char ReadBuf[30];
char ScanBuf[30];int main(void)
{int fd = -1;int i = 0;//打开设备文件if ((fd = open(FILE_NAME, O_RDWR)) < 0){printf("%s open error\n", FILE_NAME);return -1;}while (1){memset(ScanBuf, 0, sizeof(ScanBuf));printf("please input data for LED\n");if (scanf("%s", ScanBuf)){//打开LED设备if (!strcmp(ScanBuf, "on")){write(fd, "1", 1);}//关闭LED设备else if (!strcmp(ScanBuf, "off")){write(fd, "0", 1);}//闪烁LED设备else if (!strcmp(ScanBuf, "flash")){for (i=5; i>0; i--){ioctl(fd, LED_ON);sleep(1);ioctl(fd, LED_OFF);sleep(1);}}else {break;}}}close(fd);return 0;
}