55 строки
2.4 KiB
ReStructuredText
55 строки
2.4 KiB
ReStructuredText
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Kernel driver w1_ds2423
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=======================
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Supported chips:
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* Maxim DS2423 based counter devices.
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supported family codes:
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=============== ====
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W1_THERM_DS2423 0x1D
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=============== ====
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Author: Mika Laitio <lamikr@pilppa.org>
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Description
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-----------
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Support is provided through the sysfs w1_slave file. Each opening and
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read sequence of w1_slave file initiates the read of counters and ram
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available in DS2423 pages 12 - 15.
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Result of each page is provided as an ASCII output where each counter
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value and associated ram buffer is outpputed to own line.
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Each lines will contain the values of 42 bytes read from the counter and
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memory page along the crc=YES or NO for indicating whether the read operation
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was successful and CRC matched.
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If the operation was successful, there is also in the end of each line
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a counter value expressed as an integer after c=
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Meaning of 42 bytes represented is following:
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- 1 byte from ram page
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- 4 bytes for the counter value
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- 4 zero bytes
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- 2 bytes for crc16 which was calculated from the data read since the previous crc bytes
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- 31 remaining bytes from the ram page
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- crc=YES/NO indicating whether read was ok and crc matched
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- c=<int> current counter value
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example from the successful read::
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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
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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
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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
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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
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example from the read with crc errors::
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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
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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
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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
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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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