EmbedSky-irq.c
#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>
#define DEVICE_NAME "IRQ-Test"
struct button_irq_desc {
int irq;//按键对应的中断号
int pin;//按键所对应的GPIO脚
int pin_setting;//
int number;//定义键值 以传递给应用层
char *name; //按键名称
};
#if !defined (CONFIG_SKY2440_IRQ_TEST)
static struct button_irq_desc button_irqs [] = {
{IRQ_EINT1, S3C2410_GPF1, S3C2410_GPF1_EINT1, 0, "KEY1"}, /* K1 */
{IRQ_EINT4, S3C2410_GPF4, S3C2410_GPF4_EINT4, 1, "KEY2"}, /* K2 */
{IRQ_EINT2, S3C2410_GPF2, S3C2410_GPF2_EINT2, 2, "KEY3"}, /* K3 */
{IRQ_EINT0, S3C2410_GPF0, S3C2410_GPF0_EINT0, 3, "KEY4"}, /* K4 */
};
#else
static struct button_irq_desc button_irqs [] = {
{IRQ_EINT9, S3C2410_GPG1, S3C2410_GPG1_EINT9, 0, "KEY1"}, /* K1 */
{IRQ_EINT11, S3C2410_GPG3, S3C2410_GPG3_EINT11, 1, "KEY2"}, /* K2 */
{IRQ_EINT2, S3C2410_GPF2, S3C2410_GPF2_EINT2, 2, "KEY3"}, /* K3 */
{IRQ_EINT0, S3C2410_GPF0, S3C2410_GPF0_EINT0, 3, "KEY4"}, /* K4 */
};
#endif
static volatile char key_values [] = {'0', '0', '0', '0'};
static DECLARE_WAIT_QUEUE_HEAD(button_waitq);
static volatile int ev_press = 0;//没有按键按下
static irqreturn_t irq_interrupt(int irq, void *dev_id)
{
struct button_irq_desc *button_irqs = (struct button_irq_desc *)dev_id;
int down;
down = !s3c2410_gpio_getpin(button_irqs->pin);//读取dat寄存器的值,down=1表示有键按下
if (down != (key_values[button_irqs->number] & 1))
{
key_values[button_irqs->number] = '0' + down;
ev_press = 1;
wake_up_interruptible(&button_waitq);
}
return IRQ_RETVAL(IRQ_HANDLED);
}
static int tq2440_irq_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, irq_interrupt, IRQ_TYPE_EDGE_BOTH,
button_irqs.name, (void *)&button_irqs);//申请中断四个终端共用一个中断处理程序:中断号,中断处理函数,双沿触发
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 tq2440_irq_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 tq2440_irq_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)//默认为阻塞方式处理
return -EAGAIN;
else
wait_event_interruptible(button_waitq, ev_press);
}//执行到此处ev_press值为1,有按键按下了;
ev_press = 0;
err = copy_to_user(buff, (const void *)key_values, min(sizeof(key_values), count));//把按键键值拷贝给用户空间
return err ? -EFAULT : min(sizeof(key_values), count);
}
static unsigned int tq2440_irq_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 = tq2440_irq_open,
.release = tq2440_irq_close,
.read = tq2440_irq_read,
.poll = tq2440_irq_poll,//对应于select系统调用,多路监控
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,//次设备号
.name = DEVICE_NAME,
.fops = &dev_fops,
};
static int __init dev_init(void)
{
int ret;
ret = misc_register(&misc);//注册混杂设备,主设备号为10;
printk (DEVICE_NAME" initialized\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("www.embedsky.net");
MODULE_DESCRIPTION("IRQ Test for EmbedSky SKY2440/TQ2440 Board");
自己写的测试程序app-button.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/time.h>
#include <errno.h>
int main(void)
{
int buttons_fd;
int key_value;
buttons_fd = open("/dev/IRQ-Test", 0);
if (buttons_fd < 0) {
perror("open device buttons");
exit(1);
}
for (;;) {
fd_set rds;
int ret;
FD_ZERO(&rds);
FD_SET(buttons_fd, &rds);
ret = select(buttons_fd + 1, &rds, NULL, NULL, NULL);
if (ret < 0) {
perror("select");
exit(1);
}
if (ret == 0) {
printf("Timeout.\n");
} else if (FD_ISSET(buttons_fd, &rds)) {
int ret = read(buttons_fd, &key_value, sizeof key_value);
if (ret != sizeof key_value) {
if (errno != EAGAIN)
perror("read buttons\n");
continue;
} else {
printf("buttons_value: %d\n", key_value+1);
}
}
}
close(buttons_fd);
return 0;
}
程序运行之后截图入下:
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