#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/irq.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <asm/arch/regs-gpio.h>
#include <asm/hardware.h>
#define DEVICE_NAME "buttons"
#define BUTTON_MAJOR 232
struct button_irq_desc {
int irq;
unsigned long flags;
char *name;
};
static struct button_irq_desc button_irqs [] = {
{IRQ_EINT2, IRQF_TRIGGER_FALLING, "KEY1"}, /* K1 */
{IRQ_EINT3, IRQF_TRIGGER_FALLING, "KEY2"}, /* K2 */
{IRQ_EINT4, IRQF_TRIGGER_FALLING, "KEY3"}, /* K3 */
{IRQ_EINT5, IRQF_TRIGGER_FALLING, "KEY4"}, /* K4 */
};
static volatile int press_cnt [] = {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)
{
volatile int *press_cnt = (volatile int *)dev_id;
*press_cnt = *press_cnt + 1;
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;
for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++) {
err = request_irq(button_irqs[i].irq, buttons_interrupt, button_irqs[i].flags,
button_irqs[i].name, (void *)&press_cnt[i]);
if (err)
break;
}
if (err) {
i--;
for (; i >= 0; i--)
free_irq(button_irqs[i].irq, (void *)&press_cnt[i]);
return -EBUSY;
}
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++) {
free_irq(button_irqs[i].irq, (void *)&press_cnt[i]);
}
return 0;
}
static int s3c24xx_buttons_read(struct file *filp, char __user *buff, size_t count, loff_t *offp)
{
unsigned long err;
wait_event_interruptible(button_waitq, ev_press);
ev_press = 0;
err = copy_to_user(buff, (const void *)press_cnt, min(sizeof(press_cnt), count));
memset((void *)press_cnt, 0, sizeof(press_cnt));
return err ? -EFAULT : 0;
}
static struct file_operations s3c24xx_buttons_fops = {
.owner = THIS_MODULE,
.open = s3c24xx_buttons_open,
.release = s3c24xx_buttons_close,
.read = s3c24xx_buttons_read,
};
static int __init s3c24xx_buttons_init(void)
{
int ret;
ret = register_chrdev(BUTTON_MAJOR, DEVICE_NAME, &s3c24xx_buttons_fops);
if (ret < 0) {
printk(DEVICE_NAME " can‘t register major number\n");
return ret;
}
printk(DEVICE_NAME " initialized\n");
return 0;
}
static void __exit s3c24xx_buttons_exit(void)
{
unregister_chrdev(BUTTON_MAJOR, DEVICE_NAME);
}
module_init(s3c24xx_buttons_init);
module_exit(s3c24xx_buttons_exit);
MODULE_AUTHOR("litingting");
MODULE_DESCRIPTION("gec2440 BUTTON Driver");
MODULE_LICENSE("GPL");