w1_ds28e04.rst (1314B)
1======================== 2Kernel driver w1_ds28e04 3======================== 4 5Supported chips: 6 7 * Maxim DS28E04-100 4096-Bit Addressable 1-Wire EEPROM with PIO 8 9supported family codes: 10 11 ================= ==== 12 W1_FAMILY_DS28E04 0x1C 13 ================= ==== 14 15Author: Markus Franke, <franke.m@sebakmt.com> <franm@hrz.tu-chemnitz.de> 16 17Description 18----------- 19 20Support is provided through the sysfs files "eeprom" and "pio". CRC checking 21during memory accesses can optionally be enabled/disabled via the device 22attribute "crccheck". The strong pull-up can optionally be enabled/disabled 23via the module parameter "w1_strong_pullup". 24 25Memory Access 26 27 A read operation on the "eeprom" file reads the given amount of bytes 28 from the EEPROM of the DS28E04. 29 30 A write operation on the "eeprom" file writes the given byte sequence 31 to the EEPROM of the DS28E04. If CRC checking mode is enabled only 32 fully aligned blocks of 32 bytes with valid CRC16 values (in bytes 30 33 and 31) are allowed to be written. 34 35PIO Access 36 37 The 2 PIOs of the DS28E04-100 are accessible via the "pio" sysfs file. 38 39 The current status of the PIO's is returned as an 8 bit value. Bit 0/1 40 represent the state of PIO_0/PIO_1. Bits 2..7 do not care. The PIO's are 41 driven low-active, i.e. the driver delivers/expects low-active values.