【Linux内核驱动】基于platform总线的miscdevice驱动（LED）

驱动模块编写步骤：

1. 查找并调用所需的内核函数，同时为所需的结构体命名
2. 补全所需的结构体，使用vim -t查找结构体声明
3. 通过结构体声明所在的文件补全头文件

#include <linux/kernel.h>#include <linux/module.h>#include <linux/platform_device.h>#include <linux/miscdevice.h>#include <linux/gpio.h>     //gpio_request#include <plat/gpio-cfg.h>  //s3c_gpio_cfgpin#include <mach/gpio.h>      //GPIO 宏 #include <linux/fs.h>#define DRIVER_NAME "led_test"#define DEVICE_NAME "led_dev"MODULE_LICENSE("Dual BSD/GPL");MODULE_AUTHOR("[e-mail]");//避免出现struct declared inside parameter liststruct platform_deivce;struct miscdevice;static int led_plat_probe(struct platform_device *pdev);static int led_plat_remove(struct platform_deivce *pdev);struct platform_driver led_pdri = {    .probe = led_plat_probe,    .remove = led_plat_remove,    .driver = {        .name = DRIVER_NAME,        .owner = THIS_MODULE,    }};static int led_open(struct inode *inode, struct file *filp);static int led_release(struct inode *inode, struct file *filp);static long led_ioctl(struct file *filp, unsigned int cmd, unsigned int arg);struct file_operations led_fops = {    .open = led_open,    .release = led_release,    .unlocked_ioctl = led_ioctl,};struct miscdevice led_mdev = {    .minor = 10,    .name = DEVICE_NAME,    .fops = &led_fops,};/*define file operation functions*/static int led_open(struct inode *inode, struct file *filp){    printk("led open\n");    return 0;}static int led_release(struct inode *inode, struct file *filp){    printk("led release\n");    return 0;}static long led_ioctl(struct file *filp, unsigned int cmd, unsigned int arg){    printk("led ioctl\n");    switch(cmd) {        case 0:            gpio_set_value(EXYNOS4_GPL2(0), 0);            break;        case 1:            gpio_set_value(EXYNOS4_GPL2(0), 1);            break;        default:            printk("wrong cmd\n");    }    return 0;}/*define platform driver functions*/static int led_plat_probe(struct platform_device *pdev){    int error;    printk("led platform driver probe\n");    error = gpio_request(EXYNOS4_GPL2(0), "led1");    if(error < 0)        goto err_gpio_request;    s3c_gpio_cfgpin(EXYNOS4_GPL2(0), S3C_GPIO_OUTPUT);    misc_register(&led_mdev);    return 0;err_gpio_request:    printk("fail to request gpio\n");    return error;}static int led_plat_remove(struct platform_deivce *pdev){    printk("led platform driver remove\n");    misc_deregister(&led_mdev);    gpio_free(EXYNOS4_GPL2(0));    return 0;}static int led_mod_init(void){    int error;    printk("led module init\n");    printk("register led platform driver\n");    error = platform_driver_register(&led_pdri);    if(error < 0)        goto error_register_platform_driver;    printk("register platform driver success\n");    return 0;error_register_platform_driver:    printk("fail to register platform driver\n");    return -1;}static void led_mod_exit(void){    printk("led module exit\n");    printk("unregister led platform driver\n");    platform_driver_unregister(&led_pdri);}module_init(led_mod_init);module_exit(led_mod_exit);