IIC驱动程序分析（三）

来源：互联网发布：c语言编程我爱你编辑：程序博客网时间：2024/05/15 02:42

上面两个程序我们主要实现了设备的识别，但是我们发现当卸载驱动的时候并没有相关的打印信息，这时怎么回事儿呢？其实原因我们之前已经提到过了，那是因为我们在i2c_probe(adapter, &addr_data, at24cxx_detect);的功能函数at24cxx_detect里面并没有建立设备、驱动、适配器的联系，因为没有建立联系，所以卸载的时候当然不会解除联系了！那么具体应该怎么做呢？我们来看代码：

#include <linux/kernel.h>#include <linux/init.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/jiffies.h>#include <linux/i2c.h>#include <linux/mutex.h>static unsigned short ignore[]      = { I2C_CLIENT_END };static unsigned short normal_addr[] = { 0x50, I2C_CLIENT_END }; static unsigned short force_addr[] = {ANY_I2C_BUS, 0x60, I2C_CLIENT_END};static unsigned short * forces[] = {force_addr, NULL};          static struct i2c_client_address_data addr_data = { .normal_i2c = normal_addr,  .probe  = ignore, .ignore  = ignore,};static struct i2c_driver at24cxx_driver;static int at24cxx_detect(struct i2c_adapter *adapter, int address, int kind){ struct i2c_client *new_client;  printk("at24cxx_detect\n"); /* 构构一个i2c_client结构体: 以后收改数据时会用到它 */ new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);//分配 new_client->addr    = address;//这是设备地址 new_client->adapter = adapter;这时适配器 new_client->driver  = &at24cxx_driver;//这是驱动 strcpy(new_client->name, "at24cxx");//这是名字 i2c_attach_client(new_client);//添加联系  return 0;}static int at24cxx_attach(struct i2c_adapter *adapter){ return i2c_probe(adapter, &addr_data, at24cxx_detect);}static int at24cxx_detach(struct i2c_client *client){ printk("at24cxx_detach\n"); i2c_detach_client(client); kfree(i2c_get_clientdata(client)); return 0;}static struct i2c_driver at24cxx_driver = { .driver = {  .name = "at24cxx", }, .attach_adapter = at24cxx_attach, .detach_client  = at24cxx_detach,};static int at24cxx_init(void){ i2c_add_driver(&at24cxx_driver); return 0;}static void at24cxx_exit(void){ i2c_del_driver(&at24cxx_driver);}module_init(at24cxx_init);module_exit(at24cxx_exit);MODULE_LICENSE("GPL");

这样的话卸载的时候就会有打印信息了！