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2011-12-22 21:08:50
原文地址：ARM-linux嵌入式内核驱动——按键的驱动 作者：luozhiyong131
/*************************************
按键的驱动，在TX2440A上做测试
维护记录： 2009-10-28 V1.0
2009-03-08 V1.1
linux内核：2.6.31
硬件接法：
KEY1 --> GPF4
KEY2 --> GPF5
KEY3 --> GPF6
KEY4 --> GPF7
*************************************/
#include
#include
#include
#include
#include
#include
#include
#include
//#include
#include
//#include
#include
#include
#include
#include
#define BUFFER_SIZE 256
#define DEVICE_NAME "TX2440-button" /* 设备名称 */
static int BUTTON_MAJOR = 0; /* 主设备号 */
static volatile int key_values [] = {0, 0, 0, 0};
static DECLARE_WAIT_QUEUE_HEAD(button_waitq);
static volatile int ev_press = 0;
struct button_irq_desc
{
int irq;
int pin;
int pin_setting;
int number;
char *name;
};
/* 用来指定按键所用的外部中断引脚及中断触发方式, 名字 */
static struct button_irq_desc button_irqs [] =
{
{IRQ_EINT4, S3C2410_GPF(4), S3C2410_GPF4_EINT4, 0, "KEY1"}, /* K1 */
{IRQ_EINT5, S3C2410_GPF(5), S3C2410_GPF5_EINT5, 1, "KEY2"}, /* K2 */
{IRQ_EINT6, S3C2410_GPF(6), S3C2410_GPF6_EINT6, 2, "KEY3"}, /* K3 */
{IRQ_EINT7, S3C2410_GPF(7), S3C2410_GPF7_EINT7, 3, "KEY4"}, /* K4 */
};
static void open_irqs(void)
{
int i;
for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++)
{
enable_irq(button_irqs[i].irq);
}
}
static void close_irqs(void)
{
int i;
for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++)
{
disable_irq(button_irqs[i].irq);
}
}
static irqreturn_t buttons_interrupt(int irq, void *dev_id)
{
struct button_irq_desc *button_irqs = (struct button_irq_desc *)dev_id;
int key_press = s3c2410_gpio_getpin(button_irqs->pin);
if (key_press == 0)
{
mdelay(20);
key_press = s3c2410_gpio_getpin(button_irqs->pin);
if (key_press == 0)
{
key_values[button_irqs->number] = (button_irqs->number + 1);
ev_press = 1;
wake_up_interruptible(&button_waitq);
}
}
return IRQ_RETVAL(IRQ_HANDLED);
}
static void register_irqsrv(void)
{
int i;
int err;
for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++)
{
// 注册中断处理函数
s3c2410_gpio_cfgpin(button_irqs[i].pin,button_irqs[i].pin_setting);
err = request_irq(button_irqs[i].irq, buttons_interrupt, NULL, button_irqs[i].name, (void *)&button_irqs[i]);
if (err)
break;
}
if (err)
{
// 释放已经注册的中断
i--;
for (; i >= 0; i--)
{
disable_irq(button_irqs[i].irq);
free_irq(button_irqs[i].irq, (void *)&button_irqs[i]);
}
return -EBUSY;
}
}
static void unregister_irqsrv(void)
{
int i;
for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++)
{
free_irq(button_irqs[i].irq, (void *)&button_irqs[i]);
}
}
static int TX2440_button_open(struct inode *inode, struct file *file)
{
open_irqs();
printk("TX2440-BUTTON Driver Open Called!\n");
return 0;
}
static int TX2440_button_close(struct inode *inode, struct file *file)
{
close_irqs();
printk("TX2440-BUTTON Driver Release Called!\n");
return 0;
}
static int TX2440_button_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));
memset((void *)key_values, 0, sizeof(key_values));
return err ? -EFAULT : min(sizeof(key_values), count);
}
static unsigned int TX2440_button_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 TX2440_button_fops =
{
.owner = THIS_MODULE,
.open = TX2440_button_open,
.release = TX2440_button_close,
.read = TX2440_button_read,
.poll = TX2440_button_poll,
};
static struct class *button_class;
static int __init TX2440_button_init(void)
{
printk("TX2440 BUTTON DRIVER MODULE INIT\n");
register_irqsrv();
close_irqs();
BUTTON_MAJOR = register_chrdev(0, DEVICE_NAME, &TX2440_button_fops);
if (BUTTON_MAJOR < 0)
{
printk(DEVICE_NAME " can't register major number\n");
return BUTTON_MAJOR;
}
printk("register TX2440-Button Driver OK! Major = %d\n", BUTTON_MAJOR);
button_class = class_create(THIS_MODULE, DEVICE_NAME);
if(IS_ERR(button_class))
{
printk("Err: failed in TX2440-Button class. \n");
return -1;
}
device_create(button_class, NULL, MKDEV(BUTTON_MAJOR, 0), NULL, DEVICE_NAME);
printk(DEVICE_NAME " initialized\n");
return 0;
}
static void __exit TX2440_button_exit(void)
{
printk("TX2440 BUTTON DRIVER MODULE EXIT\n");
close_irqs();
unregister_irqsrv();
unregister_chrdev(BUTTON_MAJOR, DEVICE_NAME);
device_destroy(button_class, MKDEV(BUTTON_MAJOR, 0));
class_destroy(button_class);
}
module_init(TX2440_button_init);
module_exit(TX2440_button_exit);
MODULE_AUTHOR("www.txmcu.com");
MODULE_DESCRIPTION("TX2440 Button Driver");
MODULE_LICENSE("GPL");
源代码：
TX2440_button.rar
测试程序： key.rar
