Linux下 button 驱动

<pre name="code" class="cpp">#include <linux/module.h>#include <linux/kernel.h>#include <linux/fs.h>#include <linux/init.h>#include <linux/delay.h>#include <linux/poll.h>#include <linux/irq.h>#include <asm/irq.h>#include <linux/interrupt.h>#include <asm/uaccess.h>#include <mach/regs-gpio.h>#include <mach/hardware.h>#include <linux/platform_device.h>#include <linux/cdev.h>#include <linux/miscdevice.h>#include <linux/gpio.h>#include <linux/sched.h>#define DEVICE_NAME     "buttons_liu"//#define DEBUG struct button_irq_desc {    int irq;    int pin;    int pin_setting;    int number;    char *name;};#if !defined (CONFIG_QQ2440_BUTTONS)static struct button_irq_desc button_irqs [] = {    {IRQ_EINT8 , S3C2410_GPG0 ,  S3C2410_GPG0_EINT8  , 0, "KEY0"},    {IRQ_EINT11, S3C2410_GPG3 ,  S3C2410_GPG3_EINT11 , 1, "KEY1"},    {IRQ_EINT13, S3C2410_GPG5 ,  S3C2410_GPG5_EINT13 , 2, "KEY2"},    {IRQ_EINT14, S3C2410_GPG6 ,  S3C2410_GPG6_EINT14 , 3, "KEY3"},    {IRQ_EINT15, S3C2410_GPG7 ,  S3C2410_GPG7_EINT15 , 4, "KEY4"},    {IRQ_EINT19, S3C2410_GPG11,  S3C2410_GPG11_EINT19, 5, "KEY5"},};#else /* means QQ */static struct button_irq_desc button_irqs [] = {    {IRQ_EINT19, S3C2410_GPG11, S3C2410_GPG11_EINT19, 0, "KEY0"},    {IRQ_EINT11, S3C2410_GPG3,  S3C2410_GPG3_EINT11,  1, "KEY1"},    {IRQ_EINT2,  S3C2410_GPF2,  S3C2410_GPF2_EINT2,   2, "KEY2"},    {IRQ_EINT0,  S3C2410_GPF0,  S3C2410_GPF0_EINT0,   3, "KEY3"},    {       -1,            -1,                 -1,    4, "KEY4"},    {       -1,            -1,                 -1,    5, "KEY5"},};#endif//static volatile char key_values [] = {'0', '0', '0', '0', '0', '0'};static int key_values = 0;static DECLARE_WAIT_QUEUE_HEAD(button_waitq);static volatile int ev_press = 0;static irqreturn_t buttons_interrupt(int irq, void *dev_id){    struct button_irq_desc *button_irqs = (struct button_irq_desc *)dev_id;    int down;    // udelay(0);        /*上升沿触发，GPIO DAT 应该为非0 的数*/    down = !s3c2410_gpio_getpin(button_irqs->pin);  //按下down = 1 = !0 //松开down = 0 = !1    if (!down) { //printk("rising\n");key_values = button_irqs->number;        ev_press = 1;                          //表示中断发生了        wake_up_interruptible(&button_waitq);    }   else {//printk("falling\n");ev_press = 0;return 0;                           // irqrequest_t,可能返回两个特殊的值：IRQ_NONE和IRQ_HANDLED.   }                                                // 当中断处理程序检测到一个中断时，但该中断对应的设备并不是在注册处理函数期间指定的产生源时，返回IRQ_NONE;    return IRQ_RETVAL(IRQ_HANDLED);    // 当中断处理程序被正确调用，且确实是它所对应的设备产生了中断时，返回IRQ_HANDLED  }static int s3c24xx_buttons_open(struct inode *inode, struct file *file){    int i;    int err = 0;        for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++) {if (button_irqs[i].irq < 0) {continue;} /* 设置中断触发方式 IRQ_TYPE_EDGE_FALLING,IRQ_TYPE_EDGE_RISING,IRQ_TYPE_EDGE_BOTH ；我们这里设置为上升沿触发*/        //err = request_irq(button_irqs[i].irq, buttons_interrupt, IRQ_TYPE_EDGE_BOTH,         //                  button_irqs[i].name, (void *)&button_irqs[i]);        err = request_irq(button_irqs[i].irq, buttons_interrupt, IRQ_TYPE_EDGE_RISING,                           button_irqs[i].name, (void *)&button_irqs[i]);        if (err)            break;               //request_irq 返回0表示成功。    }    if (err) {        i--;        for (; i >= 0; i--) {    if (button_irqs[i].irq < 0) {continue;    }    disable_irq(button_irqs[i].irq);            free_irq(button_irqs[i].irq, (void *)&button_irqs[i]);        }        return -EBUSY;    }    ev_press = 0;        return 0;}static int s3c24xx_buttons_close(struct inode *inode, struct file *file){    int i;        for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++) {if (button_irqs[i].irq < 0) {    continue;}free_irq(button_irqs[i].irq, (void *)&button_irqs[i]);    }    return 0;}static int s3c24xx_buttons_read(struct file *filp, char __user *buff, size_t count, loff_t *offp){    unsigned long err;    //int i=0;    if (!ev_press) {if (filp->f_flags & O_NONBLOCK)    return -EAGAIN;else    wait_event_interruptible(button_waitq, ev_press);    }    if(count != sizeof key_values)return -EINVAL;    ev_press = 0;    err = copy_to_user(buff, &key_values, sizeof(key_values));    return sizeof(key_values);}static unsigned int s3c24xx_buttons_poll( struct file *file, struct poll_table_struct *wait){    unsigned int mask = 0;    poll_wait(file, &button_waitq, wait);    if (ev_press)        mask |= POLLIN | POLLRDNORM;    return mask;}static struct file_operations dev_fops = {    .owner   =   THIS_MODULE,    .open    =   s3c24xx_buttons_open,    .release =   s3c24xx_buttons_close,     .read    =   s3c24xx_buttons_read,    .poll    =   s3c24xx_buttons_poll,};static struct miscdevice misc = {.minor = MISC_DYNAMIC_MINOR,.name = DEVICE_NAME,.fops = &dev_fops,};static int __init dev_init(void){int ret;ret = misc_register(&misc);#ifdef DEBUGprintk("debug test\n");//ykz#endifprintk (DEVICE_NAME"\tinitialized\n");return ret;}static void __exit dev_exit(void){misc_deregister(&misc);}module_init(dev_init);module_exit(dev_exit);MODULE_LICENSE("GPL");MODULE_AUTHOR("FriendlyARM Inc.");