w1_ds2406.rst (1059B)
1======================= 2w1_ds2406 kernel driver 3======================= 4 5Supported chips: 6 7 * Maxim DS2406 (and other family 0x12) addressable switches 8 9Author: Scott Alfter <scott@alfter.us> 10 11Description 12----------- 13 14The w1_ds2406 driver allows connected devices to be switched on and off. 15These chips also provide 128 bytes of OTP EPROM, but reading/writing it is 16not supported. In TSOC-6 form, the DS2406 provides two switch outputs and 17can be provided with power on a dedicated input. In TO-92 form, it provides 18one output and uses parasitic power only. 19 20The driver provides two sysfs files. state is readable; it gives the 21current state of each switch, with PIO A in bit 0 and PIO B in bit 1. The 22driver ORs this state with 0x30, so shell scripts get an ASCII 0/1/2/3 to 23work with. output is writable; bits 0 and 1 control PIO A and B, 24respectively. Bits 2-7 are ignored, so it's safe to write ASCII data. 25 26CRCs are checked on read and write. Failed checks cause an I/O error to be 27returned. On a failed write, the switch status is not changed.