NAME¶

struct_i2c_adapter_quirks - describe flaws of an i2c adapter

SYNOPSIS¶

struct i2c_adapter_quirks {
  u64 flags;
  int max_num_msgs;
  u16 max_write_len;
  u16 max_read_len;
  u16 max_comb_1st_msg_len;
  u16 max_comb_2nd_msg_len;
};  

MEMBERS¶

flags max_num_msgs max_write_len max_read_len max_comb_1st_msg_len max_comb_2nd_msg_len

DESCRIPTION¶

Note about combined messages: Some I2C controllers can only send one message per transfer, plus something called combined message or write-then-read. This is (usually) a small write message followed by a read message and barely enough to access register based devices like EEPROMs. There is a flag to support this mode. It implies max_num_msg = 2 and does the length checks with max_comb_*_len because combined message mode usually has its own limitations. Because of HW implementations, some controllers can actually do write-then-anything or other variants. To support that, write-then-read has been broken out into smaller bits like write-first and read-second which can be combined as needed.

COPYRIGHT¶