68 static int i2c_device_match(struct device *dev, struct device_driver *drv)
69 {
70 struct i2c_client *client = i2c_verify_client(dev);
71 struct i2c_driver *driver;
72
73 if (!client)
74 return 0;
75
76 /* Attempt an OF style match */
77 if (of_driver_match_device(dev, drv))
78 return 1;
79
80 driver = to_i2c_driver(drv);
81 /* match on an id table if there is one */
82 if (driver->id_table)
83 return i2c_match_id(driver->id_table, client) != NULL;
84
85 return 0;
86 }
106 static int i2c_device_probe(struct device *dev)
107 {
108 struct i2c_client *client = i2c_verify_client(dev);
109 struct i2c_driver *driver;
110 int status;
111
112 if (!client)
113 return 0;
114
115 driver = to_i2c_driver(dev->driver);
116 if (!driver->probe || !driver->id_table)
117 return -ENODEV;
118 client->driver = driver;
119 if (!device_can_wakeup(&client->dev))
120 device_init_wakeup(&client->dev,
121 client->flags & I2C_CLIENT_WAKE);
122 dev_dbg(dev, "probe\n");
123
124 status = driver->probe(client, i2c_match_id(driver->id_table, client));// 调用底层驱动的i2c_driver结构 //实现的probe函数,i2c_match_id()函数比较的是i2c_driver结构中id_table成员的name是否与client结 //构的name一致
125 if (status) {
126 client->driver = NULL;
127 i2c_set_clientdata(client, NULL);
128 }
129 return status;
130 }
315 struct bus_type i2c_bus_type = {
316 .name = "i2c",
317 .match = i2c_device_match,
318 .probe = i2c_device_probe,
319 .remove = i2c_device_remove,
320 .shutdown = i2c_device_shutdown,
321 .pm = &i2c_device_pm_ops,
322 };
323 EXPORT_SYMBOL_GPL(i2c_bus_type);
324
325 static struct device_type i2c_client_type = {
326 .groups = i2c_dev_attr_groups,
327 .uevent = i2c_device_uevent,
328 .release = i2c_client_dev_release,
329 };
函数原型分析：
1、i2c_verify_client(struct device *dev)
332 /**
333 * i2c_verify_client - return parameter as i2c_client, or NULL
334 * @dev: device, probably from some driver model iterator
335 *
336 * When traversing the driver model tree, perhaps using driver model
337 * iterators like @device_for_each_child(), you can't assume very much
338 * about the nodes you find. Use this function to avoid oopses caused
339 * by wrongly treating some non-I2C device as an i2c_client.
340 */
341 struct i2c_client *i2c_verify_client(struct device *dev)
342 {
343 return (dev->type == &i2c_client_type)
344 ? to_i2c_client(dev)
345 : NULL;
346 }
347 EXPORT_SYMBOL(i2c_verify_client);
2、i2c_chech_client_addr_validity(const struct i2c_client *client)
i2c地址有效性检查，分10位地址、7位地址两种情况，7位地址范围为:0x00< i2c_addr <=0x7f
350 /* This is a permissive address validity check, I2C address map constraints
351 * are purposely not enforced, except for the general call address. */
352 static int i2c_check_client_addr_validity(const struct i2c_client *client)
353 {
354 if (client->flags & I2C_CLIENT_TEN) {
355 /* 10-bit address, all values are valid */
356 if (client->addr > 0x3ff)
357 return -EINVAL;
358 } else {
359 /* 7-bit address, reject the general call address */
360 if (client->addr == 0x00 || client->addr > 0x7f)
361 return -EINVAL;
362 }
363 return 0;
364 }
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