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kernel2.6.32.2mini2440led驱动之中断（去抖动）处理
kernel2.6.32.2mini2440led驱动之中断（去抖动）处理
时间：2021-07-01 10:21:17
帮助过：37人阅读
#include linux/module.h #include linux/init.h #include linux/mm.h #include linux/slab.h #include linux/types.h #include linux/semaphore.h #include linux/cdev.h #include linux/fs.h #include linux/semaphore.h #include linux/irq.h #include asm
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define LED_MAJOR 250
#define LED_NAME "leds"
#define KEY_COUNT 4
#define KEY_DELAY HZ/50
DECLARE_WAIT_QUEUE_HEAD(r_wait); ／／初始化等待队列
//wait_queue_head_t r_wait;
//init_waitqueue_head(&r_wait);
static struct timer_list key_timers[KEY_COUNT]; ／／定义定时器
static volatile bool idetify;
static void buttons_timer(unsigned long);
static unsigned long led_table [] = {
S3C2410_GPB(5),
S3C2410_GPB(6),
S3C2410_GPB(7),
S3C2410_GPB(8),
};／／位地址
static unsigned int led_cfg_table [] = {
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
};／／控制led为输入
struct button_irq_key{
int irq;
int pin;
unsigned long flags;
char *name;
};
static struct button_irq_key button_irqs[] = {
{IRQ_EINT8, S3C2410_GPG(0), IRQF_TRIGGER_FALLING, "key1"},
{IRQ_EINT11, S3C2410_GPG(3), IRQF_TRIGGER_FALLING, "key2"},
{IRQ_EINT13, S3C2410_GPG(5), IRQF_TRIGGER_FALLING, "key3"},
{IRQ_EINT14, S3C2410_GPG(6), IRQF_TRIGGER_FALLING, "key4"},
};
static volatile int press_cnt[] = {0, 0, 0, 0};
static volatile int pressed = 0;
struct leds_cdev
{
struct cdev cdev;
struct semaphore sem;
};
int leds_major = LED_MAJOR;
struct leds_cdev dev;
static irqreturn_t buttons_interrupt(int irq, void *dev_id)／／按键中断处理函数
{
// volatile int *press_count = (volatile int*)dev_id;
//disable_irq(irq);
int key = 0;
switch(irq){
case 52:
key = 0;
break;
case 55:
key = 1;
break;
case 57:
key = 2;
break;
case 58:
key = 3;
break;
default:break;
}
key_timers[key].data = key;
mod_timer(&key_timers[key], jiffies + KEY_DELAY);
printk(KERN_EMERG "irq success");
return IRQ_HANDLED;
}
static void buttons_timer(unsigned long arg)／／定时器中断处理函数，去抖实现
{
int key = arg;
int condition;
int nf;
condition = s3c2410_gpio_getpin(button_irqs[key].pin);
if(!condition)
{
while(!s3c2410_gpio_getpin(button_irqs[key].pin));
key_timers[key].expires = jiffies + KEY_DELAY;
add_timer(&key_timers[key]);
idetify = 1;
printk(KERN_EMERG "lower is appear");
}else{
if(!idetify)
return;
press_cnt[key] += 1;
nf = press_cnt[key]%2;
s3c2410_gpio_setpin(led_table[key], nf);
pressed = 1;
wake_up_interruptible(&r_wait);
idetify = 0;
printk(KERN_EMERG "up is appear%d", nf);
// enable_irq(button_irqs[key].irq);
}
// printk(KERN_EMERG "success of interruptible");
}
static int led_buttons_open(struct inode *inode, struct file *filp)
{
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]); ／／请求中断
if(err)
break;
/* init_timer(&key_timers[i]);
key_timers[i].data = i;
key_timers[i].function = buttons_timer;
*/
setup_timer(&key_timers[i], buttons_timer, i);初始化定时器
}
//key_timers[0].expires = jiffies + 3 * HZ;
//add_timer(&key_timers[0]);
if(err){
i--;
for(; i >= 0; i--)
free_irq(button_irqs[i].irq, (void *)press_cnt[i]);
return -EBUSY;
}
return 0;
}
static ssize_t led_buttons_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
{
unsigned long err;
wait_event_interruptible(r_wait, pressed);
pressed = 0;
err = copy_to_user(buf, (const void *)press_cnt, sizeof(press_cnt));
memset((void *)press_cnt, 0, sizeof(press_cnt));
return err ? -EFAULT : 0 ;
}
static int led_buttons_close(struct inode *inode, struct file *filp)
{
int i;
for(i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++){
free_irq(button_irqs[i].irq, (void*)&press_cnt[i]);／／释放中断号
del_timer(&key_timers[i]);
}
return 0;
}
static int leds_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
{
switch(cmd)
{
case 0:
if(arg > 4){
return -EINVAL;
}
down(&dev.sem);
s3c2410_gpio_setpin(led_table[arg], 0);
up(&dev.sem);
return 0;
case 1:
if(arg > 4){
return -EINVAL;
}
down(&dev.sem);
s3c2410_gpio_setpin(led_table[arg], 1);
up(&dev.sem);
return 0;
default:
return -EINVAL;
}
}
struct file_operations cdev_fops = {
.owner = THIS_MODULE,
.ioctl = leds_ioctl,
.open = led_buttons_open,
.read = led_buttons_read,
.release = led_buttons_close,
};
static void leds_setup(struct leds_cdev *dev, int index)
{
int err, devno = MKDEV(leds_major, index);
cdev_init(&dev->cdev, &cdev_fops);
dev->cdev.owner = THIS_MODULE;
dev->cdev.ops = &cdev_fops;
err = cdev_add(&dev->cdev, devno, 1);
if(err)
printk(KERN_NOTICE "Error %d adding LED %d\n", err, index);
}
static int __init dev_init(void) ／／module初始化与注册
{
int result;
int i;
// struct class *my_class;
dev_t devno = MKDEV(leds_major, 0);
for(i = 0; i < 4; i++ ){
s3c2410_gpio_cfgpin(led_table[i], led_cfg_table[i]);
s3c2410_gpio_setpin(led_table[i], 0);
}
if(leds_major)
result = register_chrdev_region(devno, 1, "leds");
else{
result = alloc_chrdev_region(&devno, 0, 1, "leds");
leds_major = devno;
}
if(result < 0)
return result;
leds_setup(&dev, 0);
sema_init(&dev.sem, 1);
/* my_class = class_create(THIS_MODULE, LED_NAME);
if(IS_ERR(my_class))
{
printk("Err:failed in creating class.\n");
return -1;
}
device_create(my_class, NULL, MKDEV(leds_major, 0), LED_NAME, 0);
*/
return 0;
}
void __exit dev_exit(void)
{
cdev_del(&dev.cdev);
unregister_chrdev_region(MKDEV(leds_major, 0), 1);
}
module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("emperor");
MODULE_DESCRIPTION("LED MODULE");
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