1 Kernel driver w1_ds2423 1 Kernel driver w1_ds2423
2 ======================= 2 =======================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * Maxim DS2423 based counter devices. 6 * Maxim DS2423 based counter devices.
7 7
8 supported family codes: 8 supported family codes:
9 9
10 =============== ==== 10 =============== ====
11 W1_THERM_DS2423 0x1D 11 W1_THERM_DS2423 0x1D
12 =============== ==== 12 =============== ====
13 13
14 Author: Mika Laitio <lamikr@pilppa.org> 14 Author: Mika Laitio <lamikr@pilppa.org>
15 15
16 Description 16 Description
17 ----------- 17 -----------
18 18
19 Support is provided through the sysfs w1_slave 19 Support is provided through the sysfs w1_slave file. Each opening and
20 read sequence of w1_slave file initiates the r 20 read sequence of w1_slave file initiates the read of counters and ram
21 available in DS2423 pages 12 - 15. 21 available in DS2423 pages 12 - 15.
22 22
23 Result of each page is provided as an ASCII ou 23 Result of each page is provided as an ASCII output where each counter
24 value and associated ram buffer is outpputed t 24 value and associated ram buffer is outpputed to own line.
25 25
26 Each lines will contain the values of 42 bytes 26 Each lines will contain the values of 42 bytes read from the counter and
27 memory page along the crc=YES or NO for indica 27 memory page along the crc=YES or NO for indicating whether the read operation
28 was successful and CRC matched. 28 was successful and CRC matched.
29 If the operation was successful, there is also 29 If the operation was successful, there is also in the end of each line
30 a counter value expressed as an integer after 30 a counter value expressed as an integer after c=
31 31
32 Meaning of 42 bytes represented is following: 32 Meaning of 42 bytes represented is following:
33 33
34 - 1 byte from ram page 34 - 1 byte from ram page
35 - 4 bytes for the counter value 35 - 4 bytes for the counter value
36 - 4 zero bytes 36 - 4 zero bytes
37 - 2 bytes for crc16 which was calculated from 37 - 2 bytes for crc16 which was calculated from the data read since the previous crc bytes
38 - 31 remaining bytes from the ram page 38 - 31 remaining bytes from the ram page
39 - crc=YES/NO indicating whether read was ok a 39 - crc=YES/NO indicating whether read was ok and crc matched
40 - c=<int> current counter value 40 - c=<int> current counter value
41 41
42 example from the successful read:: 42 example from the successful read::
43 43
44 00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 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 00 00 00 00 00 e0 1f 00 ff ff 00 45 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
46 00 29 c6 5d 18 00 00 00 00 04 37 00 ff ff 00 46 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
47 00 05 00 00 00 00 00 00 00 8d 39 ff ff ff ff 47 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
48 48
49 example from the read with crc errors:: 49 example from the read with crc errors::
50 50
51 00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 51 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
52 00 02 00 00 22 00 00 00 00 e0 1f 00 ff ff 00 52 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
53 00 e1 61 5d 19 00 00 00 00 df 0b 00 ff ff 00 53 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
54 00 05 00 00 20 00 00 00 00 8d 39 ff ff ff ff 54 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
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