s3c2410按键驱动完整版.doc

/* 2410 中断按键驱动*基于s3c2410的16个按键驱动，采用中断的方式，实现了阻塞和非阻塞，并用定时*器进行了消抖处理消抖，也实现的异步通知，POLL机制，每个源文件我都加了比较 *详细的注释。各位刚刚学习ARM/Linux *驱动的同学可以参考。*/ button_irq_driver .c 驱动源文件 / button_irq_test.c 应用程序-按键测试（open可实现阻塞和非阻塞）/ button_poll_test.c 应用程序-poll机制按键测试/ button_fasync.c 应用程序-异步通知方式按键测试/* button_irq_driver .c */#include#include#include#include#include#include#include#include#include#includestatic unsigned int buttons_major = 0;/本地结构体,表示一个按键struct fsbuttons_cdevstruct cdev *buttons_cdev; /按键设备结构体struct class *buttons_class;/所属类unsigned int key_buttons; /按键管脚电?1 /0wait_queue_head_t buttons_wq;struct timer_list button_timer;static struct fsbuttons_cdev *fs_buttons ;/构建一个结构体,用来描述中断管脚struct fspinint irq;int pin;char *name;int num;int row_input;int row_output;int int_put;int key_val;static struct fspin fspin_desc4=IRQ_EINT0,S3C2410_GPF0,row0, 0, S3C2410_GPF0_INP,S3C2410_GPF0_OUTP,S3C2410_GPF0_EINT0,IRQ_EINT2,S3C2410_GPF2,row1, 1, S3C2410_GPF2_INP, S3C2410_GPF2_OUTP,S3C2410_GPF2_EINT2,IRQ_EINT11,S3C2410_GPG3,row2, 2,S3C2410_GPG3_INP, S3C2410_GPG3_OUTP,S3C2410_GPG3_EINT11,IRQ_EINT19,S3C2410_GPG11,row3,3, S3C2410_GPG11_INP, S3C2410_GPG11_OUTP,S3C2410_GPG11_EINT19,;struct pin_col int pin;int col_input;int col_output;static struct pin_col col_line4 = S3C2410_GPE11,S3C2410_GPE11_INP,S3C2410_GPE11_OUTP,S3C2410_GPG6,S3C2410_GPG6_INP,S3C2410_GPG6_OUTP,S3C2410_GPE13,S3C2410_GPE13_INP,S3C2410_GPE13_OUTP,S3C2410_GPG2,S3C2410_GPG2_INP,S3C2410_GPG2_OUTP,;static int key_comfirm44=10,11,12,16,7,8,9,15,4,5,6,14,1,2,3,13,;/*构建异步通知注册函数用到的结构体*/struct fasync_struct *fsbuttons_fasync;struct fspin *cur_pin;static void set_col_output(void)int i;for(i = 0;i4;i+)s3c2410_gpio_cfgpin(col_linei.pin, col_linei.col_output);s3c2410_gpio_setpin(col_linei.pin,0);static void set_col_input(void)inti;for(i = 0;ipin);if(val_sec != cur_pin-key_val)return IRQ_NONE;row = cur_pin-num;/*将发生中断的引脚配置为输出低电平*/s3c2410_gpio_cfgpin(cur_pin-pin, cur_pin-row_output);s3c2410_gpio_setpin(cur_pin-pin, 0);/*将kscan0-kscan3设为输入并拉高*/set_col_input();/* 轮询列线，看哪个管脚为0，为0的那列保存起来*/for(i = 0;ikey_buttons= key_comfirmrowcol;/*恢复*/*将列线恢复为输出，并且输出为0*/set_col_output();/*将产生中断的管脚，再次恢复为中断功能*/s3c2410_gpio_cfgpin(cur_pin-pin,cur_pin-int_put);/*唤醒休眠的进程*/wake_up_interruptible(&(fs_buttons-buttons_wq);/*异步通知，发信号*/kill_fasync(&fsbuttons_fasync, SIGIO, POLLIN);return IRQ_HANDLED;/typedef int irqreturn_t;/#define IRQ_NONE(0)/处理失败/#define IRQ_HANDLED(1)/处理成功/#define IRQ_RETVAL(x)(x) != 0)/无效的static irqreturn_t buttons_irq_handler_fun(int irq, void *dev_id)cur_pin = (struct fspin *)dev_id;/*获取管脚状态*/cur_pin-key_val= s3c2410_gpio_getpin(cur_pin-pin);/*有键按 键按下*/if(cur_pin-key_val= 0)/*重载定时器*/mod_timer(&fs_buttons-button_timer, jiffies +5);returnIRQ_HANDLED;static int buttons_open(struct inode *inode, struct file *file)int i ;int ret = -1;/*初始化设备*/*设置 kscan0 引脚 为输出。输出为0*/set_col_output();/*注册中断 ,下降沿触发，中断 名，中断id*/for(i =0 ;ibutton_timer);fs_buttons-button_timer.expires= jiffies +5;fs_buttons-button_timer.function =(void *)button_timer_fun;/*加载定时器*/add_timer(&fs_buttons-button_timer);/*初始化 等待队列头*/init_waitqueue_head(&fs_buttons-buttons_wq);return 0;static ssize_t buttons_read(struct file *filp, char _user *buf, size_t count, loff_t *opps)int ret;/*1.如果没有按键,而且应用程序是以非阻塞方式打开,就直接返回*/if(fs_buttons-key_buttons = 0) & (filp-f_flags & O_NONBLOCK)return 0;/*1.如果没有键值key_buttons = 0 ,则休眠*/wait_event_interruptible(fs_buttons-buttons_wq,fs_buttons-key_buttons);/*2.如果有键值,将键值返回用户空间*/*如果拷贝成功则返回0,否则返回剩下的没有拷贝完的字节数*/ret = copy_to_user(buf, &fs_buttons-key_buttons, count);fs_buttons-key_buttons = 0; /键值清0return 1;static ssize_t buttons_write(struct file *file, const char _user *buf, size_t count, loff_t *opps)return 0;/*异步通知*/int buttons_fasync(int fd, struct file *file , int on)int error = 0;/*想办法将file中的某些参数拿出来,实际上就是在设置fsbuttons_fasync结构体*/error = fasync_helper(fd, file, on, &fsbuttons_fasync);return error;static unsigned int buttons_poll(struct file * file, struct poll_table_struct *wait)int mask = 0;/*1.将进程挂入等待队列,但是并不休眠*/poll_wait(file, &(fs_buttons-buttons_wq), wait);/*2.查看是否有事件*/if(fs_buttons-key_buttons)mask |= POLLIN;return mask;int buttons_close(struct inode *inode, struct file *file)int i;for(i = 0;ibuttons_cdev = cdev_alloc();/*初始化*/cdev_init(fs_buttons-buttons_cdev, &buttons_fops);/*加载cdev*/cdev_add(fs_buttons-buttons_cdev, MKDEV(buttons_major,0), 1);static int _init buttons_init(void)int devno;/*申请设备号，注册*/if(buttons_major)/*静态方式*/devno = MKDEV(buttons_major,0);register_chrdev_region(devno, 1, buttons_driver);else/*动态方式*/alloc_chrdev_region(&devno, 0, 1, buttons_driver);buttons_major = MAJOR(devno);/*2.分配空间, *GFP_KERNEL:如果分配空间不成功,则会休眠 */fs_buttons=kmalloc(sizeof(fs_buttons), GFP_KERNEL);/*构建cdev*/setup_fsbuttons_cdev();/*创建设备文件*/fs_buttons-buttons_class = class_create(THIS_MODULE,buttons);class_device_create(fs_buttons-buttons_class, NULL, MKDEV(buttons_major,0), NULL, buttons);return 0;static void _exit buttons_exit(void)unregister_chrdev_region(MKDEV(buttons_major,0), 1);kfree(fs_buttons);cdev_del(fs_buttons-buttons_cdev);class_device_destroy(fs_buttons-buttons_class, MKDEV(buttons_major,0);class_destroy(fs_buttons-buttons_class);module_init(buttons_init);module_exit(buttons_exit);MODULE_LICENSE(GPL);/* button_irq_test.c */#include#include#include #include #include int main(void)int fd = -1;int val = -1;int ret = -1;/fd = open(/dev/buttons,O_RDWR|O_NONBLOCK);fd = open(/dev/buttons,O_RDWR);if(fd 0)perror(open);exit(-1);while(1)ret = read(fd,&val,4);if(ret 0)perror(read);exit(-1); printf(val = %dn,val);return 0;/* button_poll_test.c */#include#include#include #include #include #include int main(void)int fd = -1;int val = -1;int ret = -1;struct pollfd poll_fd1;/fd = open(/dev/buttons,O_RDWR|O_NONBLOCK);f