Summary
HOST
When the I2C host probe , it will make one adapter and some clients those share the same adapter. The program will initiate the client->dev , and put the dev into the kernel, at same time the program will fill the client->name with the device info (from the __i2c_board_list) .
DEVICE
When use i2c_add_driver add I2C driver , the program will use the i2c_device_id name find the client (which has the same name ),and fill the client-driver with the I2C driver.