字符设备中添加系统休眠与唤醒接口

本例实现在字符设备中添加系统休眠与唤醒的接口，使得在系统进入休眠和唤醒时候能够调用相关代码。关于休眠相关理论知识请自行上网查阅。

#include <linux/module.h>#include <linux/kernel.h>#include <linux/fs.h>#include <linux/init.h>#include <linux/delay.h>#include <asm/uaccess.h>#include <asm/irq.h>#include <asm/io.h>#include <mach/gpio.h>#include <mach/hardware.h>#include <linux/device.h>#include <linux/cdev.h> #include <linux/slab.h>#include <linux/gpio.h>#include <linux/platform_device.h>#include <mach/sys_config.h>#define DEV_DBG_EN   1#if(DEV_DBG_EN == 1)   #define rwbuffer_dev_dbg(x,arg...) printk(KERN_INFO"[LS_DEBUG][RWBUFF]"x,##arg)#else   #define rwbuffer_dev_dbg(x,arg...) #endif#define rwbuffer_dev_err(x,arg...) printk(KERN_ERR"[LS_ERR][RWBUFF]"x,##arg)#define rwbuffer_dev_print(x,arg...) printk(KERN_INFO"[LS_PRINT][RWBUFF]"x,##arg)#define CHRDEV_NAME      "rwbuffer"#define CLASS_NAME       "rwbuffer"#define DEVICE_NAME      "rwbuffer"static dev_t         devid;static struct cdev*  rwbuff_cdev;static struct class* rwbuff_class;#define EDOG_POWER_GPIO        (GPIOH(07))static int rwbuff_open(struct inode *inode,struct file *file)  {    rwbuffer_dev_dbg("open rwbuffer device!");    return 0;}static ssize_t rwbuff_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)  {rwbuffer_dev_dbg("write rwbuffer device!");return count;}static int rwbuff_release(struct inode *inode, struct file *file)  {    rwbuffer_dev_dbg("close rwbuffer device!");    return 0;}static int __init edog_power_probe(struct platform_device *pdev)  {rwbuffer_dev_dbg("call %s\n",__func__);     return 0;}static int __exit edog_power_remove(struct platform_device *pdev)  {rwbuffer_dev_dbg("call %s\n",__func__);return 0;}static int edog_power_suspend(struct platform_device *pdev, pm_message_t mesg)  {rwbuffer_dev_dbg("call %s\n",__func__);return 0;}static int edog_power_resume(struct platform_device *pdev)  {rwbuffer_dev_dbg("call %s\n",__func__);return 0;}static struct platform_driver rwbuffer_driver = {.driver = {.name= "rwbuffer",.owner= THIS_MODULE,},.probe      = edog_power_probe,.remove= __exit_p(edog_power_remove),.suspend= edog_power_suspend,.resume= edog_power_resume,};static struct platform_device rwbuff_device = {.name           = "rwbuffer",    .id             = 0,};static struct file_operations fops_rwbuff = {   .owner          = THIS_MODULE,   .open           = rwbuff_open,   .release        = rwbuff_release,   .write          = rwbuff_write,};/** @function:edog_power_init* This function is a init function of this modules,it such as module_init.* @return unknown.*/static int __init edog_power_init(void)  {int ret;//get dev number.ret = alloc_chrdev_region(&devid,0,1,CHRDEV_NAME);if(ret)  {rwbuffer_dev_err("alloc char driver error!\n");return ret;}//register char dev.rwbuff_cdev = cdev_alloc();cdev_init(rwbuff_cdev,&fops_rwbuff);rwbuff_cdev->owner = THIS_MODULE;ret = cdev_add(rwbuff_cdev,devid,1);if(ret)  {rwbuffer_dev_err("cdev create error!\n");goto regiseter_clean;}//create device.rwbuff_class = class_create(THIS_MODULE,CLASS_NAME);if(IS_ERR(rwbuff_class))  {        rwbuffer_dev_err("create class error\n");goto cdev_clean;}device_create(rwbuff_class,NULL,devid,NULL,DEVICE_NAME);ret = platform_device_register(&rwbuff_device);if (ret) {rwbuffer_dev_err("platform device register failed\n");goto device_clean;}    return  platform_driver_probe(&rwbuffer_driver, edog_power_probe);;device_clean:device_destroy(rwbuff_class,devid);class_clean:class_destroy(rwbuff_class);cdev_clean:cdev_del(rwbuff_cdev);regiseter_clean:unregister_chrdev_region(devid,1);return -ENOMEM;}/*** @function:edog_power_exit* This function is a clean function of this module.*/static void __exit edog_power_exit(void) {    rwbuffer_dev_dbg("edog driver exit is ok!\n");    platform_driver_unregister(&rwbuffer_driver);device_destroy(rwbuff_class,devid);class_destroy(rwbuff_class);cdev_del(rwbuff_cdev);unregister_chrdev_region(devid,1);}late_initcall(edog_power_init);module_exit(edog_power_exit);MODULE_AUTHOR("[e-mail]");MODULE_DESCRIPTION("landsem sysconfig driver.");MODULE_LICENSE("GPL");