diff options
Diffstat (limited to 'kernel/Documentation/w1/slaves')
| -rw-r--r-- | kernel/Documentation/w1/slaves/00-INDEX | 8 | ||||
| -rw-r--r-- | kernel/Documentation/w1/slaves/w1_ds2406 | 25 | ||||
| -rw-r--r-- | kernel/Documentation/w1/slaves/w1_ds2423 | 47 | ||||
| -rw-r--r-- | kernel/Documentation/w1/slaves/w1_ds28e04 | 36 | ||||
| -rw-r--r-- | kernel/Documentation/w1/slaves/w1_therm | 50 |
5 files changed, 166 insertions, 0 deletions
diff --git a/kernel/Documentation/w1/slaves/00-INDEX b/kernel/Documentation/w1/slaves/00-INDEX new file mode 100644 index 000000000..6e18c70c3 --- /dev/null +++ b/kernel/Documentation/w1/slaves/00-INDEX @@ -0,0 +1,8 @@ +00-INDEX + - This file +w1_therm + - The Maxim/Dallas Semiconductor ds18*20 temperature sensor. +w1_ds2423 + - The Maxim/Dallas Semiconductor ds2423 counter device. +w1_ds28e04 + - The Maxim/Dallas Semiconductor ds28e04 eeprom. diff --git a/kernel/Documentation/w1/slaves/w1_ds2406 b/kernel/Documentation/w1/slaves/w1_ds2406 new file mode 100644 index 000000000..8137fe6f6 --- /dev/null +++ b/kernel/Documentation/w1/slaves/w1_ds2406 @@ -0,0 +1,25 @@ +w1_ds2406 kernel driver +======================= + +Supported chips: + * Maxim DS2406 (and other family 0x12) addressable switches + +Author: Scott Alfter <scott@alfter.us> + +Description +----------- + +The w1_ds2406 driver allows connected devices to be switched on and off. +These chips also provide 128 bytes of OTP EPROM, but reading/writing it is +not supported. In TSOC-6 form, the DS2406 provides two switch outputs and +can be provided with power on a dedicated input. In TO-92 form, it provides +one output and uses parasitic power only. + +The driver provides two sysfs files. state is readable; it gives the +current state of each switch, with PIO A in bit 0 and PIO B in bit 1. The +driver ORs this state with 0x30, so shell scripts get an ASCII 0/1/2/3 to +work with. output is writable; bits 0 and 1 control PIO A and B, +respectively. Bits 2-7 are ignored, so it's safe to write ASCII data. + +CRCs are checked on read and write. Failed checks cause an I/O error to be +returned. On a failed write, the switch status is not changed. diff --git a/kernel/Documentation/w1/slaves/w1_ds2423 b/kernel/Documentation/w1/slaves/w1_ds2423 new file mode 100644 index 000000000..3f98b505a --- /dev/null +++ b/kernel/Documentation/w1/slaves/w1_ds2423 @@ -0,0 +1,47 @@ +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 diff --git a/kernel/Documentation/w1/slaves/w1_ds28e04 b/kernel/Documentation/w1/slaves/w1_ds28e04 new file mode 100644 index 000000000..7819b65cf --- /dev/null +++ b/kernel/Documentation/w1/slaves/w1_ds28e04 @@ -0,0 +1,36 @@ +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. diff --git a/kernel/Documentation/w1/slaves/w1_therm b/kernel/Documentation/w1/slaves/w1_therm new file mode 100644 index 000000000..cc62a95e4 --- /dev/null +++ b/kernel/Documentation/w1/slaves/w1_therm @@ -0,0 +1,50 @@ +Kernel driver w1_therm +==================== + +Supported chips: + * Maxim ds18*20 based temperature sensors. + * Maxim ds1825 based temperature sensors. + +Author: Evgeniy Polyakov <johnpol@2ka.mipt.ru> + + +Description +----------- + +w1_therm provides basic temperature conversion for ds18*20 devices. +supported family codes: +W1_THERM_DS18S20 0x10 +W1_THERM_DS1822 0x22 +W1_THERM_DS18B20 0x28 +W1_THERM_DS1825 0x3B + +Support is provided through the sysfs w1_slave file. Each open and +read sequence will initiate a temperature conversion then provide two +lines of ASCII output. The first line contains the nine hex bytes +read along with a calculated crc value and YES or NO if it matched. +If the crc matched the returned values are retained. The second line +displays the retained values along with a temperature in millidegrees +Centigrade after t=. + +Parasite powered devices are limited to one slave performing a +temperature conversion at a time. If none of the devices are parasite +powered it would be possible to convert all the devices at the same +time and then go back to read individual sensors. That isn't +currently supported. The driver also doesn't support reduced +precision (which would also reduce the conversion time). + +The module parameter strong_pullup can be set to 0 to disable the +strong pullup, 1 to enable autodetection or 2 to force strong pullup. +In case of autodetection, the driver will use the "READ POWER SUPPLY" +command to check if there are pariste powered devices on the bus. +If so, it will activate the master's strong pullup. +In case the detection of parasite devices using this command fails +(seems to be the case with some DS18S20) the strong pullup can +be force-enabled. +If the strong pullup is enabled, the master's strong pullup will be +driven when the conversion is taking place, provided the master driver +does support the strong pullup (or it falls back to a pullup +resistor). The DS18b20 temperature sensor specification lists a +maximum current draw of 1.5mA and that a 5k pullup resistor is not +sufficient. The strong pullup is designed to provide the additional +current required. |