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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
这里我仅仅贴出了代码和应用,没有进行其它的解说。由于之前我写过的按键驱动的恩恩怨怨,解说的很清楚,这个驱动就是依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) //应用中没用到这样的方式 { int val; if (size != 1) return -EINVAL; if (file->f_flags & O_NONBLOCK) { if (!ev_press) return -EAGAIN; } else { /* 假设没有按键动作, 休眠 */ wait_event_interruptible(button_waitq, ev_press); } /* 假设有按键动作, 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,推向编译模块时自己主动创建的__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依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.应用測试
#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; }
远程视频监控之驱动篇(按键)
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