|
- /*
- misc device driver ,add the extern interrupt to asy connect with
- the user application.
- */
- #include <linux/module.h>
- #include <linux/fs.h>
- #include <linux/miscdevice.h>
- #include <linux/init.h>
- #include <linux/gpio.h>
- #include <linux/interrupt.h>
- #include <linux/mm.h>
- #include <linux/slab.h>
- #include <linux/sched.h>
- #include <asm/uaccess.h>
- #define GPIO_TO_PIN(bank, gpio) (32 * (bank) + (gpio))
- #define DEVICE_NAME "hello"
- #define MAX_KEY_BUF 16
- #define KEY_NUM 2
- #define KEYSTATUS_UP 0
- #define KEYSTATUS_DOWNX 2
- #define KEYSTATUS_DOWN 1
- #define KEY_TIMER_DELAY 200
- typedef unsigned char KEY_RET ;
- static struct key_info
- {
- const char *desc;
- int gpio_port;
- int key_no;
- } key_info_tab[KEY_NUM] =
- {
- {"KEY_1",GPIO_TO_PIN(1, 16),0},
- {"KEY_2",GPIO_TO_PIN(1, 17),1},
- };
- static struct key_dev
- {
- unsigned int keystatus[KEY_NUM];
- KEY_RET buf[MAX_KEY_BUF];
- unsigned int head ,tail;
- wait_queue_head_t wq;
- struct miscdevice miscdev;
- } *keydevp;
- static struct timer_list key_timer[KEY_NUM];/*按键的延时*/
- int ISKEY_DOWN(int k)
- {
- unsigned int gpio = key_info_tab[k].gpio_port;
- printk("gpio(%d)_get_value:%d\n",gpio,gpio_get_value(gpio));
- return gpio_get_value(gpio);
- }
- /*按键延时处理函数*/
- void keyboard_timer_handler(unsigned long data)
- {
- int key = data;
- printk("handler data is:%d",key);
- if (ISKEY_DOWN(key))
- {
- if (keydevp->keystatus[key] == KEYSTATUS_DOWNX)
- {
- keydevp->keystatus[key] = KEYSTATUS_DOWN;
- if(keydevp->tail<MAX_KEY_BUF)
- {
- keydevp->buf[keydevp->tail] = key;
- keydevp->tail++;
- }
- else
- {
- keydevp->tail=0;
- keydevp->buf[keydevp->tail] = key;
- keydevp->tail++;
- }
- wake_up_interruptible(&(keydevp->wq));
- key_timer[key].expires = jiffies + KEY_TIMER_DELAY;
- add_timer(&key_timer[key]);
- }
- else
- {
- key_timer[key].expires = jiffies + KEY_TIMER_DELAY;
- add_timer(&key_timer[key]);
- }
- }
- else
- {
- keydevp->keystatus[key] = KEYSTATUS_UP;
- del_timer(&key_timer[key]);
- enable_irq(gpio_to_irq(key_info_tab[key].gpio_port));
- }
- }
- /*中断处理顶半部*/
- static irqreturn_t keyboard_interrupt(int irq,void *dev_id){
- struct key_info *key;
- key = dev_id;
- disable_irq(gpio_to_irq(key->gpio_port));
- keydevp->keystatus[key->key_no] = KEYSTATUS_DOWNX;
- key_timer[key->key_no].expires = jiffies + KEY_TIMER_DELAY;
- add_timer(&key_timer[key->key_no]);
- return IRQ_HANDLED;
- }
- static ssize_t hello_read(struct file *filp, char __user *buf, size_t count,loff_t*ppos)
- {
- int ret ;
- retry: if (keydevp->head != keydevp->tail)
- {
- if(keydevp->head<MAX_KEY_BUF)
- {
- ret=copy_to_user(buf,&keydevp->buf[keydevp->head],1);
- keydevp->buf[keydevp->head]=0;
- keydevp->head++;
- return ret;
- }
- else
- {
- keydevp->head=0;
- ret=copy_to_user(buf,&keydevp->buf[keydevp->head],1);
- keydevp->buf[keydevp->head]=0;
- keydevp->head++;
- return ret;
- }
- }
- else
- {
- if (filp->f_flags &O_NONBLOCK)
- {
- return - EAGAIN;
- }
- interruptible_sleep_on(&(keydevp->wq));
- goto retry;
- }
- return 0;
- }
- static int hello_open(struct inode *inode, struct file *file)
- {
- return 0;
- }
- static int hello_close(struct inode *inode, struct file *file)
- {
- return 0;
- }
- static struct file_operations hello_fops=
- {
- .owner = THIS_MODULE,
- .open = hello_open,
- .release = hello_close,
- .read = hello_read,
- };
- static struct miscdevice misc = {
- .minor = MISC_DYNAMIC_MINOR,
- .name = DEVICE_NAME,
- .fops = &hello_fops,
- };
- /*注册按键中断*/
- int keyboard_request_irqs(void)
- {
- struct key_info *k;
- int i, ret ,irq ,irqflags;
- for(i=0;i<sizeof(key_info_tab)/sizeof(struct key_info);i++)
- {
- k = &key_info_tab[i];
- /*缺少外部中断状态设置*/
- ret = gpio_request(k->gpio_port,k->desc);
- if(ret < 0 )
- {
- printk("can't request gpio!%d error:%d\n",k->gpio_port,ret);
- return -1;
- }
- ret = gpio_direction_input(k->gpio_port);
- if(ret < 0)
- {
- printk("can't config gpio!%d error:%d\n",k->gpio_port,ret);
- return -1;
- }
- /*
- ret = gpio_set_debounce(k->gpio_port,2000);
- if(ret < 0)
- {
- printk("can't set debounce!%d error:%d\n",k->gpio_port,ret);
- return -1;
- }
- */
- irq = gpio_to_irq(k->gpio_port);
- irqflags = IRQF_SHARED | IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING;
- if(irq < 0)
- {
- printk("unable to get irq number for GPIO%d\n",k->gpio_port);
- return -1;
- }
- else
- printk("get irq(%d) number for GPIO\n",irq);
- enable_irq(irq);
- ret = request_irq(irq,keyboard_interrupt,irqflags,k->desc,k);
- if(ret < 0)
- {
- printk("can't request irq!%d error:%d\n",irq,ret);
- return -1;
- }
- printk("request resources ok!%d\n",i);
- }
- return 0;
- }
- /*释放按键中断*/
- void keyboard_free_irqs(void)
- {
- struct key_info *k;
- int i;
- for (i = 0; i < sizeof(key_info_tab) / sizeof(struct key_info); i++)
- {
- k = &key_info_tab[i];
- gpio_free(k->gpio_port);
- free_irq(gpio_to_irq(k->gpio_port), k);
- printk("free resources ok!%d\n",i);
- }
- }
- static int __init hello_init(void)
- {
- int ret , i;
- ret=keyboard_request_irqs();
-
- /*初始化设备结构体*/
- keydevp=kmalloc(sizeof(struct key_dev),GFP_KERNEL);
- if(!keydevp)
- return - ENOMEM;
- memset(keydevp, 0, sizeof(struct key_dev));
- keydevp->head=keydevp->tail = 0;
- keydevp->miscdev=misc;
- for(i=0;i<KEY_NUM;i++)
- keydevp->keystatus[i] = KEYSTATUS_UP;
- /*初始化等待队列*/
- init_waitqueue_head(&(keydevp->wq));
- /*初始化延时定时器*/
- for(i=0;i<KEY_NUM;i++)
- setup_timer(&key_timer[i],keyboard_timer_handler,i);
- /*注册misc设备*/
- ret = misc_register(&(keydevp->miscdev));
- if(ret!=0)
- {
- printk("init hello unsuccessfully!\n");
- return -1;
- }
- printk("hello init!\n");
- return 0;
- }
- static void __exit hello_exit(void)
- {
- int i ;
- keyboard_free_irqs();
- for(i=0;i<KEY_NUM;i++)
- del_timer(&key_timer[i]);
- kfree(keydevp);
- misc_deregister(&(keydevp->miscdev));
- printk("hello exit!\n");
- }
- MODULE_LICENSE("GPL");
- module_init(hello_init);
- module_exit(hello_exit);
复制代码
这是我的全部代码,照着一些书上的例子做的。 |
|