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