| Kernel driver w1_ds2423 | |
| ======================= | |
| Supported chips: | |
| * Maxim DS2423 based counter devices. | |
| supported family codes: | |
| W1_THERM_DS2423 0x1D | |
| Author: Mika Laitio <lamikr@pilppa.org> | |
| Description | |
| ----------- | |
| Support is provided through the sysfs w1_slave file. Each opening and | |
| read sequence of w1_slave file initiates the read of counters and ram | |
| available in DS2423 pages 12 - 15. | |
| Result of each page is provided as an ASCII output where each counter | |
| value and associated ram buffer is outpputed to own line. | |
| Each lines will contain the values of 42 bytes read from the counter and | |
| memory page along the crc=YES or NO for indicating whether the read operation | |
| was successful and CRC matched. | |
| If the operation was successful, there is also in the end of each line | |
| a counter value expressed as an integer after c= | |
| Meaning of 42 bytes represented is following: | |
| - 1 byte from ram page | |
| - 4 bytes for the counter value | |
| - 4 zero bytes | |
| - 2 bytes for crc16 which was calculated from the data read since the previous crc bytes | |
| - 31 remaining bytes from the ram page | |
| - crc=YES/NO indicating whether read was ok and crc matched | |
| - c=<int> current counter value | |
| example from the successful read: | |
| 00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 00 fe ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 | |
| 00 02 00 00 00 00 00 00 00 e0 1f 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 | |
| 00 29 c6 5d 18 00 00 00 00 04 37 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=408798761 | |
| 00 05 00 00 00 00 00 00 00 8d 39 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff crc=YES c=5 | |
| example from the read with crc errors: | |
| 00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 00 fe ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 | |
| 00 02 00 00 22 00 00 00 00 e0 1f 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=NO | |
| 00 e1 61 5d 19 00 00 00 00 df 0b 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=NO | |
| 00 05 00 00 20 00 00 00 00 8d 39 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff crc=NO |