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