Commit | Line | Data |
---|---|---|
17fecb55 ML |
1 | Kernel driver w1_ds2423 |
2 | ======================= | |
3 | ||
4 | Supported chips: | |
5 | * Maxim DS2423 based counter devices. | |
6 | ||
7 | supported family codes: | |
8 | W1_THERM_DS2423 0x1D | |
9 | ||
10 | Author: Mika Laitio <lamikr@pilppa.org> | |
11 | ||
12 | Description | |
13 | ----------- | |
14 | ||
15 | Support is provided through the sysfs w1_slave file. Each opening and | |
16 | read sequence of w1_slave file initiates the read of counters and ram | |
17 | available in DS2423 pages 12 - 15. | |
18 | ||
19 | Result of each page is provided as an ASCII output where each counter | |
20 | value and associated ram buffer is outpputed to own line. | |
21 | ||
22 | Each lines will contain the values of 42 bytes read from the counter and | |
23 | memory page along the crc=YES or NO for indicating whether the read operation | |
25985edc LDM |
24 | was successful and CRC matched. |
25 | If the operation was successful, there is also in the end of each line | |
17fecb55 ML |
26 | a counter value expressed as an integer after c= |
27 | ||
28 | Meaning of 42 bytes represented is following: | |
29 | - 1 byte from ram page | |
30 | - 4 bytes for the counter value | |
31 | - 4 zero bytes | |
32 | - 2 bytes for crc16 which was calculated from the data read since the previous crc bytes | |
33 | - 31 remaining bytes from the ram page | |
34 | - crc=YES/NO indicating whether read was ok and crc matched | |
35 | - c=<int> current counter value | |
36 | ||
25985edc | 37 | example from the successful read: |
17fecb55 ML |
38 | 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 |
39 | 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 | |
40 | 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 | |
41 | 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 | |
42 | ||
43 | example from the read with crc errors: | |
44 | 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 | |
45 | 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 | |
46 | 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 | |
47 | 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 |