0001 =======================
0002 w1_ds2406 kernel driver
0003 =======================
0004
0005 Supported chips:
0006
0007 * Maxim DS2406 (and other family 0x12) addressable switches
0008
0009 Author: Scott Alfter <scott@alfter.us>
0010
0011 Description
0012 -----------
0013
0014 The w1_ds2406 driver allows connected devices to be switched on and off.
0015 These chips also provide 128 bytes of OTP EPROM, but reading/writing it is
0016 not supported. In TSOC-6 form, the DS2406 provides two switch outputs and
0017 can be provided with power on a dedicated input. In TO-92 form, it provides
0018 one output and uses parasitic power only.
0019
0020 The driver provides two sysfs files. state is readable; it gives the
0021 current state of each switch, with PIO A in bit 0 and PIO B in bit 1. The
0022 driver ORs this state with 0x30, so shell scripts get an ASCII 0/1/2/3 to
0023 work with. output is writable; bits 0 and 1 control PIO A and B,
0024 respectively. Bits 2-7 are ignored, so it's safe to write ASCII data.
0025
0026 CRCs are checked on read and write. Failed checks cause an I/O error to be
0027 returned. On a failed write, the switch status is not changed.
