远程视频监控之驱动篇（按键）

       转载请注明出处：http://blog.csdn.net/ruoyunliufeng/article/details/38515211

       这里我只贴出了代码和应用，没有进行其他的讲解。因为之前我写过的按键驱动的恩恩怨怨，讲解的非常清楚，这个驱动就是根据之前写的改写而成。连接：http://blog.csdn.net/ruoyunliufeng/article/details/23946487

一.代码

#include <linux/module.h>#include <linux/sched.h>#include <linux/kernel.h>#include <linux/fs.h>#include <linux/init.h>#include <linux/delay.h>#include <linux/irq.h>#include <asm/uaccess.h>#include <asm/irq.h>#include <asm/io.h>#include <linux/device.h>#include <mach/gpio.h>#include <linux/interrupt.h>#include <linux/poll.h>static struct class *wvm_buttons_class;static  int major;volatile unsigned long *gpfcon;volatile unsigned long *gpfdat;volatile unsigned long *gpgcon;volatile unsigned long *gpgdat;static struct timer_list buttons_timer;static DECLARE_WAIT_QUEUE_HEAD(button_waitq);/* 中断事件标志, 中断服务程序将它置1，sixth_drv_read将它清0 */static volatile int ev_press = 0;static struct fasync_struct *button_async;struct pin_desc{unsigned int pin;unsigned int key_val;};/* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 *//* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */static unsigned char key_val;struct pin_desc pins_desc[4] = {{S3C2410_GPF(0), 0x01},{S3C2410_GPF(3), 0x02},{S3C2410_GPG(5), 0x03},{S3C2410_GPG(6), 0x04},};static struct pin_desc *irq_pd;struct semaphore button_lock;/*  * 确定按键值  */static irqreturn_t buttons_irq(int irq, void *dev_id){/* 20ms后启动定时器 */irq_pd = (struct pin_desc *)dev_id;mod_timer(&buttons_timer, jiffies+HZ/50);return IRQ_RETVAL(IRQ_HANDLED);}static int wvm_buttons_drv_open(struct inode *inode, struct file *file){        static int IRQ_EINT8_r,IRQ_EINT11_r,IRQ_EINT13_r,IRQ_EINT14_r;if (file->f_flags & O_NONBLOCK){       if (down_trylock(&button_lock))return -EBUSY;}else{/* 获取信号量 */down(&button_lock);}/* 配置GPF0,2为输入引脚 *//* 配置GPG3,11为输入引脚 */IRQ_EINT8_r=request_irq(IRQ_EINT8,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S2", &pins_desc[0]);if (IRQ_EINT8_r)return -EBUSY;IRQ_EINT11_r=request_irq(IRQ_EINT11,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S3", &pins_desc[1]);if (IRQ_EINT11_r)return -EBUSY;IRQ_EINT13_r=request_irq(IRQ_EINT13, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S4", &pins_desc[2]);if (IRQ_EINT13_r)return -EBUSY;IRQ_EINT14_r=request_irq(IRQ_EINT14, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S5", &pins_desc[3]);if (IRQ_EINT14_r)return -EBUSY;return 0;}ssize_t wvm_buttons_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) //应用中没用到这种方式{int val;if (size != 1)return -EINVAL;if (file->f_flags & O_NONBLOCK){if (!ev_press)return -EAGAIN;}else{/* 如果没有按键动作, 休眠 */wait_event_interruptible(button_waitq, ev_press);}/* 如果有按键动作, 返回键值 */val=copy_to_user(buf, &key_val, 1);if(val)return -EAGAIN;ev_press = 0;return 1;}static int wvm_buttons_drv_fasync (int fd, struct file *filp, int on){printk("driver: wvm_buttons_fasync\n");return fasync_helper (fd, filp, on, &button_async);}int wvm_buttons_drv_close(struct inode *inode, struct file *file){//atomic_inc(&canopen);free_irq(IRQ_EINT8,  &pins_desc[0]);free_irq(IRQ_EINT11, &pins_desc[1]);free_irq(IRQ_EINT13, &pins_desc[2]);free_irq(IRQ_EINT14, &pins_desc[3]);up(&button_lock);return 0;}static struct file_operations wvm_buttons_drv_fops = {        .owner   =  THIS_MODULE,    /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */        .open    =  wvm_buttons_drv_open,     .read =  wvm_buttons_drv_read,   .release =  wvm_buttons_drv_close,.fasync =  wvm_buttons_drv_fasync,};static void buttons_timer_function(unsigned long data){struct pin_desc * pindesc = irq_pd;unsigned int pinval;if (!pindesc)return;pinval = s3c2410_gpio_getpin(pindesc->pin);if (pinval){/* 松开 */key_val = 0x80 | pindesc->key_val;}else{/* 按下 */key_val = pindesc->key_val;}        ev_press = 1;                  /* 表示中断发生了 */        wake_up_interruptible(&button_waitq);   /* 唤醒休眠的进程 */kill_fasync (&button_async, SIGIO, POLL_IN);}static int wvm_buttons_drv_init(void) //入口{init_timer(&buttons_timer);buttons_timer.function = buttons_timer_function;add_timer(&buttons_timer); major = register_chrdev(0, "wvm_buttons", &wvm_buttons_drv_fops);if(major < 0)        {          printk(  " wvm_buttons register falid!/n");          return major;        }wvm_buttons_class = class_create(THIS_MODULE, "wvm_buttons");if(IS_ERR(wvm_buttons_class))        {          printk( " wvm_buttons register class falid!/n");          return -1;        }/* 为了让mdev根据这些信息来创建设备节点 */device_create(wvm_buttons_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);gpfdat = gpfcon + 1;gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);gpgdat = gpgcon + 1;sema_init(&button_lock, 1);return 0;}static void wvm_buttons_drv_exit(void)  //出口{unregister_chrdev(major, "wvm_buttons");device_destroy(wvm_buttons_class, MKDEV(major, 0));class_destroy(wvm_buttons_class);iounmap(gpfcon);iounmap(gpgcon);}module_init(wvm_buttons_drv_init);module_exit(wvm_buttons_drv_exit);MODULE_LICENSE("GPL");

二.应用测试

#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <stdio.h>#include <poll.h>#include <signal.h>#include <sys/types.h>#include <unistd.h>#include <fcntl.h>/* wvm_buttonstest   */int fd;void my_signal_fun(int signum){unsigned char key_val;read(fd, &key_val, 1);printf("key_val: 0x%x\n", key_val);}int main(int argc, char **argv){unsigned char key_val;int ret;int Oflags;signal(SIGIO, my_signal_fun);fd = open("/dev/buttons", O_RDWR);if (fd < 0){printf("can't open!\n");}fcntl(fd, F_SETOWN, getpid());Oflags = fcntl(fd, F_GETFL); fcntl(fd, F_SETFL, Oflags | FASYNC);while (1){sleep(1000);}return 0;}