static const struct i2c_device_id *
i2c_match_id(const struct i2c_device_id *id,const struct i2c_client *client)
{
while (id->name[0]) {
if (strcmp(client->name, id->name) == 0)
//比較名字
return id;
id++;
}
return NULL;
}
static int
i2c_device_match(struct device *dev, struct device_driver *drv)
{
struct i2c_client *client = i2c_verify_client(dev);
struct i2c_driver *driver;
if (!client)
return 0;
driver = to_i2c_driver(drv);
/* match on an id table if there is one */
if (driver->id_table)
//id_table表示該驅動所支持的設備的id表
return
i2c_match_id(driver->id_table, client) != NULL;
return 0;
}
static int i2c_device_probe(struct device *dev)
{
struct i2c_client *client = i2c_verify_client(dev);
struct i2c_driver *driver;
driver = to_i2c_driver(dev->driver);
.....
status =
driver->probe(client, i2c_match_id(driver->id_table, client));
//probe
...
}
struct bus_type
i2c_bus_type = {
.name = "
i2c",
.match =
i2c_device_match,
.probe = i2c_device_probe,
.remove = i2c_device_remove,
.shutdown = i2c_device_shutdown,
.suspend = i2c_device_suspend,
.resume = i2c_device_resume,
};
static int __init i2c_init(void)
{
int retval;
retval =
bus_register(&
i2c_bus_type);
if (retval)
return retval;
#ifdef CONFIG_I2C_COMPAT
i2c_adapter_compat_class = class_compat_register("i2c-adapter");
if (!i2c_adapter_compat_class) {
retval = -ENOMEM;
goto bus_err;
}
#endif
retval =
i2c_add_driver(&dummy_driver);
//虛擬的驅動
if (retval)
goto class_err;
return 0;
}
/* We must initialize early, because some subsystems register i2c drivers
* in subsys_initcall() code, but are linked (and initialized) before i2c.
*/
postcore_initcall(i2c_init);
