OK6410按键驱动程序(Linux)，测试通过后分享给大家

如果你的飞凌Linux-3.0.1内核源码没有编译过，编译时可能会出现：

scripts/basic/fixdep: 1: scripts/basic/fixdep: ELF

: not found
scripts/basic/fixdep: 2: scripts/basic/fixdep: Syntax error: "(" unexpected

这时要先到Linux-3.0.1目录下 执行make scripts

注意：由于OK6410的GPIO按键中断已经被飞凌自带的按键驱动注册，所以运行我们编写的按键驱动前要先去掉飞凌自带的按键驱动，方法：make menuconfig->Device Drivers->input device support->Key Boards->GPIO Buttons 去掉前面的*，即不选该项即可。

按键驱动：

#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/sched.h>#include <linux/gpio.h>#include <mach/gpio-bank-n.h>#define DEVICE_NAME     "buttons"struct button_irq_desc {    int irq;    int pin;    int pin_setting;    int number;    char *name;};static struct button_irq_desc button_irqs [] = {    {IRQ_EINT(0), S3C64XX_GPN(0) ,  S3C64XX_GPN0_EINT0 , 0, "KEY0"},    {IRQ_EINT(1), S3C64XX_GPN(1) ,  S3C64XX_GPN1_EINT1 , 1, "KEY1"},    {IRQ_EINT(2), S3C64XX_GPN(2) ,  S3C64XX_GPN2_EINT2 , 2, "KEY2"},    {IRQ_EINT(3), S3C64XX_GPN(3) ,  S3C64XX_GPN3_EINT3 , 3, "KEY3"},    {IRQ_EINT(4), S3C64XX_GPN(4) ,  S3C64XX_GPN4_EINT4 , 4, "KEY4"},    {IRQ_EINT(5), S3C64XX_GPN(5),   S3C64XX_GPN5_EINT5 , 5, "KEY5"},};static volatile int key_values [] = {0, 0, 0, 0, 0, 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);    down = !gpio_get_value(button_irqs->pin);//按键发生了变化    if (down != (key_values[button_irqs->number] & 1)) { // Changedkey_values[button_irqs->number] = 0 + down;        ev_press = 1;        wake_up_interruptible(&button_waitq);    }        return IRQ_RETVAL(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;}/*注册中断，六个按钮全都由buttons_interrupt中断函数处理，上升下降沿都触发中断 这里用button_irqs[i]的地址作为dev_id,保证dev_id的唯一性，发生中断的时候， 会把这个指针传递给中断处理函数*/        err = request_irq(button_irqs[i].irq, buttons_interrupt, IRQ_TYPE_EDGE_BOTH,                           button_irqs[i].name, (void *)&button_irqs[i]);        if (err)            break;    }//如果注册中断过程中出错，则注销注册成功的中断    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 = 1;        return 0;}static int s3c24xx_buttons_close(struct inode *inode, struct file *file){    int i;    //注销中断    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;    if (!ev_press) {//没有新按键事件处理，如果用户要求不阻塞就直接返回，否则阻塞在button_waitq队列上。if (filp->f_flags & O_NONBLOCK)    return -EAGAIN;else    wait_event_interruptible(button_waitq, ev_press);    }        ev_press = 0;    err = copy_to_user(buff, (const void *)key_values, min(sizeof(key_values), count));    return err ? -EFAULT : min(sizeof(key_values), count);}static unsigned int s3c24xx_buttons_poll( struct file *file, struct poll_table_struct *wait){    unsigned int mask = 0;//使用poll_wait将等待队列添加到poll_table中    poll_wait(file, &button_waitq, wait);//返回掩码:设备可读通常返回（POLLIN|POLLRDNORM）。设备可写通常返回（POLLOUT|POLLWRNORM）    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);printk (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("wuwuchuan");

Makefile

    ifneq ($(KERNELRELEASE),)            obj-m := buttons.o            else                KDIR := /home/wu55uw/forlinx/linux-3.0.1      all:          make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=arm-linux-      clean:          rm -f *.ko *.o *.mod.o *.mod.c *.symvers  modul*            endif  

测试程序：

 #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/ioctl.h> int main(int argc, char **argv) {     int fd;     int val;     int i;     int key_value[6];           fd = open("/dev/buttons",0);     if(fd<0) {       printf("open devie error\n");       return -1;     }     while(1) {       val = read(fd,key_value, sizeof(key_value));       if(val<0) {         printf("read error\n");         continue;       }       for(i=0;i<6;i++) {          if(key_value[i])          printf("KEY%d pressed\n",(i+1),key_value[i]);  else  printf("KEY%d released\n",(i+1),key_value[i]);       }         printf("----------------new key event----------------\n");     }     close(fd);     return 0; }

测试结果：