最近在看中断驱动，有些疑问：在按键中断程序（mini2440_buttons.c）中，好像没有看到和硬件初始化有关的部分，比如说把GPIO配置成中断输入， 中断相关寄存器（ EINTMASK、 EINTPEND）的设置等等，这些工作都是内核做的吗？是不是在request_irq指定要申请的中断号后，内核把中断号对应的硬件的相关工作已经做了？ 还有request_irq函数的dev_id参数，在非共享中断时是不是也可以使用？   求解答

本人新手 有木有人给解答下

可参考：http://www.aiothome.net/read.php?tid-13606.html

他那个是裸机下的，linux下友善给的内核里有个按键中断的例子，mini2440_buttons.c 代码如下
这里面好像没有设置中断相关寄存器的部分，是内核帮助完成的吗？

#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>

#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_EINT8 , S3C2410_GPG(0) , S3C2410_GPG0_EINT8 , 0, "KEY0"},
  {IRQ_EINT11, S3C2410_GPG(3) , S3C2410_GPG3_EINT11 , 1, "KEY1"},
  {IRQ_EINT13, S3C2410_GPG(5) , S3C2410_GPG5_EINT13 , 2, "KEY2"},
  {IRQ_EINT14, S3C2410_GPG(6) , S3C2410_GPG6_EINT14 , 3, "KEY3"},
  {IRQ_EINT15, S3C2410_GPG(7) , S3C2410_GPG7_EINT15 , 4, "KEY4"},
  {IRQ_EINT19, S3C2410_GPG(11), S3C2410_GPG11_EINT19, 5, "KEY5"},
};
static volatile char 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 = !s3c2410_gpio_getpin(button_irqs->pin);

  if (down != (key_values[button_irqs->number] & 1)) { // Changed

key_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.irq < 0) {
continue;
}
  err = request_irq(button_irqs.irq, buttons_interrupt, IRQ_TYPE_EDGE_BOTH,  
  button_irqs.name, (void *)&button_irqs);
  if (err)
  break;
  }

  if (err) {
  i--;
  for (; i >= 0; i--) {
if (button_irqs.irq < 0) {
continue;
}
disable_irq(button_irqs.irq);
  free_irq(button_irqs.irq, (void *)&button_irqs);
  }
  return -EBUSY;
  }

  ev_press = 1;
    
  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.irq < 0) {
continue;
}
free_irq(button_irqs.irq, (void *)&button_irqs);
  }

  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) {
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;
  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);

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("FriendlyARM Inc.");