怎样在Linux驱动中创建proc节点（示例）

一、定义proc节点的读、写函数

static int tp_switch_writeproc(struct file *file,const char *buffer,

unsigned long count,void *data)

{

sscanf(buffer,"%d", &tp_dbg);

printk("tpd: proc-->tp_dbg = %d\n", tp_dbg);

return count;

}

static int tp_switch_readproc(char *page, char **start, off_t off,

int count,int *eof, void *data)

{

int len;

unsigned char tmp =tp_dbg&0x0F;

len = sprintf(page,"%c\n", tmp);

return 2;

}

二、驱动加载时创建proc节点的入口

#include <linux/proc_fs.h>
static struct proc_dir_entry *tp_root;
static struct proc_dir_entry *debug_entry;
#define USER_ROOT_DIR "tp_debug"
#define USER_ENTRY1 "debug_switch"

staticint goodix_ts_probe(struct i2c_client *client, const struct i2c_device_id *id)

{

… …

init_debug_port(); //创建proc调试节点

… …

}

static int init_debug_port(void)

{

pt_root =proc_mkdir(USER_ROOT_DIR, NULL);

if (NULL==pt_root)

{

printk(KERN_ALERT"Create dir /proc/%s error!\n", USER_ROOT_DIR);

return -1;

}

printk(KERN_INFO"Create dir /proc/%s\n", USER_ROOT_DIR);

// Create a test entryunder USER_ROOT_DIR

pt_entry1 =create_proc_entry(USER_ENTRY1, 0666, pt_root);

if (NULL ==pt_entry1)

{

printk(KERN_ALERT"Create entry %s under /proc/%s error!\n",

USER_ENTRY1,USER_ROOT_DIR);

goto err_out;

}

pt_entry1->write_proc= tp_switch_writeproc;

pt_entry1->read_proc =tp_switch_readproc;

printk(KERN_INFO"Create /proc/%s/%s\n",

USER_ROOT_DIR,USER_ENTRY1);

return 0;

err_out:

pt_entry1->read_proc =NULL;

pt_entry1->write_proc= NULL;

remove_proc_entry(USER_ROOT_DIR,pt_root);

return -1;

}

三、卸载驱动时删除proc节点

static void remove_debug_port(void)

{

remove_proc_entry(USER_ENTRY1,pt_root);

remove_proc_entry(USER_ROOT_DIR,NULL);

}

static int goodix_ts_remove(struct i2c_client *client)

{

… …

remove_debug_port();

… …

}