42 lines
1.3 KiB
ReStructuredText
42 lines
1.3 KiB
ReStructuredText
|
========================
|
||
|
|
Kernel driver w1_ds28e04
|
||
|
|
========================
|
||
|
|
|
||
|
|
Supported chips:
|
||
|
|
|
||
|
|
* Maxim DS28E04-100 4096-Bit Addressable 1-Wire EEPROM with PIO
|
||
|
|
|
||
|
|
supported family codes:
|
||
|
|
|
||
|
|
================= ====
|
||
|
|
W1_FAMILY_DS28E04 0x1C
|
||
|
|
================= ====
|
||
|
|
|
||
|
|
Author: Markus Franke, <franke.m@sebakmt.com> <franm@hrz.tu-chemnitz.de>
|
||
|
|
|
||
|
|
Description
|
||
|
|
-----------
|
||
|
|
|
||
|
|
Support is provided through the sysfs files "eeprom" and "pio". CRC checking
|
||
|
|
during memory accesses can optionally be enabled/disabled via the device
|
||
|
|
attribute "crccheck". The strong pull-up can optionally be enabled/disabled
|
||
|
|
via the module parameter "w1_strong_pullup".
|
||
|
|
|
||
|
|
Memory Access
|
||
|
|
|
||
|
|
A read operation on the "eeprom" file reads the given amount of bytes
|
||
|
|
from the EEPROM of the DS28E04.
|
||
|
|
|
||
|
|
A write operation on the "eeprom" file writes the given byte sequence
|
||
|
|
to the EEPROM of the DS28E04. If CRC checking mode is enabled only
|
||
|
|
fully aligned blocks of 32 bytes with valid CRC16 values (in bytes 30
|
||
|
|
and 31) are allowed to be written.
|
||
|
|
|
||
|
|
PIO Access
|
||
|
|
|
||
|
|
The 2 PIOs of the DS28E04-100 are accessible via the "pio" sysfs file.
|
||
|
|
|
||
|
|
The current status of the PIO's is returned as an 8 bit value. Bit 0/1
|
||
|
|
represent the state of PIO_0/PIO_1. Bits 2..7 do not care. The PIO's are
|
||
|
|
driven low-active, i.e. the driver delivers/expects low-active values.
|