46.Linux电源管理-休眠与唤醒

#include <linux/module.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/sched.h> #include <linux/pm.h> #include <linux/slab.h> #include <linux/sysctl.h> #include <linux/proc_fs.h> #include <linux/delay.h> #include <linux/platform_device.h> #include <linux/input.h> #include <linux/gpio_keys.h> #include <linux/workqueue.h> #include <linux/gpio.h> #include <linux/of_platform.h> #include <linux/of_gpio.h> #include <linux/spinlock.h> #include <soc/gpio.h> #define MYKEY_GPIO GPIO_PB(31) static DECLARE_WAIT_QUEUE_HEAD(mykey_waitqueue); struct mykey_button { unsigned int gpio; const char *desc; int wakeup; /*唤醒源*/ int debounce_interval; /* 防抖动 时间ms*/ int wait_event; /*等待队列事件*/ int key_val; /*按键值*/ int irq; struct timer_list timer; /*防抖动定时器*/ struct work_struct work; struct device *dev; }; static struct mykey_button mykey_data={ .gpio = MYKEY_GPIO, .desc = "mykey", .wakeup = 1, .debounce_interval = 10, //10ms .wait_event = 0, }; static void mykey_func(struct work_struct *work) { struct mykey_button *data = container_of(work, struct mykey_button, work); //通过work成员变量找到父结构体 if(data->wakeup) { pm_wakeup_event(data->dev, 0); } data->key_val =gpio_get_value(data->gpio); data->wait_event =1; wake_up_interruptible(&mykey_waitqueue); //唤醒队列 }
 static void mykey_irq_timer(unsigned long _data) { struct mykey_button *data =(struct mykey_button *)_data; schedule_work(&data->work); //调用mykey_func()函数 } static irqreturn_t mykey_irq(int irq, void *dev_id) { struct mykey_button *data = dev_id; if(data->debounce_interval) mod_timer(&data->timer, jiffies+msecs_to_jiffies(10)); else schedule_work(&data->work); return IRQ_HANDLED; } static ssize_t mykey_read(struct file *file, char __user *user, size_t count, loff_t *ppos) { wait_event_interruptible(mykey_waitqueue,mykey_data.wait_event ); //进入等待队列休眠,如果中断来数据,则跳出 copy_to_user(user, &mykey_data.key_val, sizeof(mykey_data.key_val)); mykey_data.wait_event =0; return 0; } static int mykey_open(struct inode *inode, struct file *file) { int err=0; int irq; err=gpio_request_one(mykey_data.gpio, GPIOF_DIR_IN, mykey_data.desc); //获取管脚,并设置管脚为输入 if (err < 0) { printk("mykey_open err : gpio_request_one err=%dn",err); return -EINVAL; } irq = gpio_to_irq(mykey_data.gpio); //获取IRQ中断号,用来注册中断 if(irq<0) { err =irq; printk("mykey_open err : gpio_to_irq err=%dn",irq); goto fail; } mykey_data.irq = irq; INIT_WORK(&mykey_data.work, mykey_func); //初始化工作队列  err=request_irq(irq,mykey_irq,IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING, mykey_data.desc,&mykey_data); if (err) { printk("mykey_open err : request_irq err=%dn",err); goto fail; } if(mykey_data.wakeup) enable_irq_wake(irq); //将引脚设为唤醒源 if(mykey_data.debounce_interval) setup_timer(&mykey_data.timer, mykey_irq_timer, (unsigned long)&mykey_data); //设置定时器return 0; fail: if (gpio_is_valid(mykey_data.gpio)) gpio_free(mykey_data.gpio); return err; }
 static int mykey_release(struct inode *inode, struct file *file) { free_irq(mykey_data.irq,&mykey_data); cancel_work_sync(&mykey_data.work); if(mykey_data.wakeup) disable_irq_wake(mykey_data.irq); if(mykey_data.debounce_interval) del_timer_sync(&mykey_data.timer); gpio_free(mykey_data.gpio); return 0; } struct file_operations mykey_ops={ .owner = THIS_MODULE, .open = mykey_open, .read = mykey_read, .release=mykey_release, }; static int major; static struct class *cls; static int mykey_init(void) { struct device *mydev; major=register_chrdev(0,"mykey", &mykey_ops); cls=class_create(THIS_MODULE, "mykey"); mydev = device_create(cls, 0, MKDEV(major,0),&mykey_data,"mykey"); mykey_data.dev = mydev; return 0; } static void mykey_exit(void) { device_destroy(cls, MKDEV(major,0)); class_destroy(cls); unregister_chrdev(major, "mykey"); } module_init(mykey_init); module_exit(mykey_exit); MODULE_LICENSE("GPL");