2440_key_driver.rar_按键2440

#include <linux/init.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/types.h> #include <linux/fs.h> #include <linux/slab.h> #include <linux/cdev.h> #include <linux/device.h> #include <linux/semaphore.h> #include <linux/sched.h> #include <linux/workqueue.h> #include <mach/hardware.h> #include <mach/regs-gpio.h> #include <mach/regs-gpioj.h> #include <asm/io.h> #include <asm/uaccess.h> #include <asm/delay.h> #include "key_io.h" #define KEY_MAJOR 0 // 定义主设备号 0--自动分配 非零手动分配 #define KEY_MINOR 0 // 定义次设备号 一般由0开始 typedef struct { struct cdev cdev; // 字符设备结构体 struct class *cls; struct device *dev; struct rw_semaphore rw_sem; struct timer_list timer; struct work_struct key_work; u16 key_data; u16 key_bak_data; u32 key_count; } ST_S3C_KEY_DRV, *LPST_S3C_KEY_DRV; static int key_open(struct inode *inode, struct file *filp); static int key_release(struct inode *inode, struct file *filp); static ssize_t key_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos); static void key_work_handler(struct work_struct *work); static inline u16 to_real_key_val(u32 ch); static inline void key_setup_pin(void); static void timer_handler(unsigned long data); static int key_major = KEY_MAJOR; static int key_minor = KEY_MINOR; static int key_nr_devs = 1; // 字符设备的个数 static const char key_dev_name[] = "s3c_key"; // 注册的名称 ST_S3C_KEY_DRV *pstS3ckeyDrv = NULL; //文件操作结构体 static const struct file_operations key_fops = { .owner = THIS_MODULE, .read = key_read, .open = key_open, .release = key_release, }; static int __init s3c_key_init(void) { int err; dev_t devno = MKDEV(key_major, 0); /***********************申请字符设备************************/ if(key_major) {// 手动申请 err = register_chrdev_region(devno, key_nr_devs, key_dev_name); } else {// 内核自动申请 err = alloc_chrdev_region(&devno, key_minor, key_nr_devs, key_dev_name); key_major = MAJOR(devno); } if (err < 0) { printk("s3c_key can't get the major %d\n", key_major); return err; } else { printk(KERN_DEBUG "s3c_key success get the major is %d\n", key_major); } /**************注册字符设备的具体方法**********************/ pstS3ckeyDrv = kmalloc(sizeof(ST_S3C_KEY_DRV), GFP_KERNEL); if (pstS3ckeyDrv == NULL) { err = -ENOMEM; goto fail_malloc; } memset(pstS3ckeyDrv, 0, sizeof(ST_S3C_KEY_DRV)); cdev_init(&pstS3ckeyDrv->cdev, &key_fops); // 与文件操作函数关联起来 pstS3ckeyDrv->cdev.owner = THIS_MODULE; init_rwsem(&pstS3ckeyDrv->rw_sem); INIT_WORK(&pstS3ckeyDrv->key_work, key_work_handler); init_timer(&pstS3ckeyDrv->timer); //add 后所有方法生效 在此之前进一步设置硬件 key_setup_pin(); pstS3ckeyDrv->key_data = to_real_key_val(0); pstS3ckeyDrv->key_bak_data = to_real_key_val(0); pstS3ckeyDrv->key_count = 10; err = cdev_add(&pstS3ckeyDrv->cdev, devno, 1); if (err < 0) { printk("cdev_add fail\n"); goto fail_cdev_add; } // 为proc文件系统 创建一个设备类 pstS3ckeyDrv->cls = class_create(THIS_MODULE, key_dev_name); // 为该类 创建一个设备 pstS3ckeyDrv->dev = device_create(pstS3ckeyDrv->cls, NULL, MKDEV(key_major, 0), NULL, "%s", "s3c_key_dev"); pstS3ckeyDrv->timer.function = timer_handler; pstS3ckeyDrv->timer.data = (unsigned long)pstS3ckeyDrv; pstS3ckeyDrv->timer.expires = jiffies + (10 * HZ / 1000); // 10ms为单位 add_timer(&pstS3ckeyDrv->timer); return 0; fail_cdev_add: kfree(pstS3ckeyDrv); fail_malloc: unregister_chrdev_region(MKDEV(key_major, key_minor),key_nr_devs); return err; } static void __exit s3c_key_exit(void) { del_timer(&pstS3ckeyDrv->timer); cdev_del(&pstS3ckeyDrv->cdev); unregister_chrdev_region(MKDEV(KEY_MAJOR, KEY_MINOR), key_nr_devs); device_destroy(pstS3ckeyDrv->cls, MKDEV(KEY_MAJOR, 0)); class_destroy(pstS3ckeyDrv->cls); kfree(pstS3ckeyDrv); printk(KERN_DEBUG "s3c_di exit...\n"); } static int key_open(struct inode *inode, struct file *filp) { return 0; } static int key_release(struct inode *inode, struct file *filp) { return 0; } static ssize_t key_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos) { if (size != sizeof(u16)) { //printk("size error\n"); return -EINVAL; } down_read(&pstS3ckeyDrv->rw_sem); if (copy_to_user(buf, &pstS3ckeyDrv->key_data, sizeof(u16))) { up_read(&pstS3ckeyDrv->rw_sem); //printk("copy_to_user error\n"); return -EBUSY; } else { up_read(&pstS3ckeyDrv->rw_sem); //printk("copy_to_user success\n"); return sizeof(u16); } } static inline u16 to_real_key_val(u32 ch) { if (ch >= 0 && ch <= 3) { if (s3c2410_gpio_getpin(S3C2410_GPF4 + ch)) { return 500; } else { return 0; } } else {// 超出范围 返回高电平 return 500; } } static void key_work_handler(struct work_struct *work) { LPST_S3C_KEY_DRV pS3cDiDrv = container_of(work, ST_S3C_KEY_DRV, key_work); pS3cDiDrv->key_bak_data = to_real_key_val(0); // 获取读锁 down_read(&pS3cDiDrv->rw_sem); if (pS3cDiDrv->key_bak_data != pS3cDiDrv->key_data) { up_read(&pS3cDiDrv->rw_sem); if (pS3cDiDrv->key_count) { pS3cDiDrv->key_count -= 1; if (pS3cDiDrv->key_count == 0) {// 更新key_data down_write(&pS3cDiDrv->rw_sem); pS3cDiDrv->key_data = pS3cDiDrv->key_bak_data; up_write(&pS3cDiDrv->rw_sem); } } } else { up_read(&pS3cDiDrv->rw_sem); pS3cDiDrv->key_count = 10; } } static void timer_handler(unsigned long data) { LPST_S3C_KEY_DRV pS3cDiDrv = (LPST_S3C_KEY_DRV)data; schedule_work(&pS3cDiDrv->key_work); mod_timer(&pS3cDiDrv->timer, jiffies + (10 * HZ / 1000)); } static inline void key_setup_pin(void) { // 4路DI输入 // // 9 s3c2410_gpio_cfgpin(S3C2410_GPF4, S3C2410_GPF4_INP); // 设置为输入 s3c2410_gpio_pullup(S3C2410_GPF4, 0); // 设置为内部上拉 // 10 //s3c2410_gpio_cfgpin(S3C2440_GPJ10, S3C2440_GPJ10_INP); // 设置为输入 //s3c2410_gpio_pullup(S3C2440_GPJ10, 0); // 设置为内部上拉 // 11 //s3c2410_gpio_cfgpin(S3C2440_GPJ11, S3C2440_GPJ11_INP); // 设置为输入 //s3c2410_gpio_pullup(S3C2440_GPJ11, 0); // 设置为内部上拉 // 12 //s3c2410_gpio_cfgpin(S3C2440_GPJ12, S3C2440_GPJ12_INP); // 设置为输入 //s3c2410_gpio_pullup(S3C2440_GPJ12, 0); // 设置为内部上拉 } module_init(s3c_key_init); module_exit(s3c_key_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("henry");