| 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. |
