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Diffstat (limited to 'Documentation/w1/slaves')
| -rw-r--r-- | Documentation/w1/slaves/index.rst | 16 | ||||
| -rw-r--r-- | Documentation/w1/slaves/w1_ds2406.rst | 27 | ||||
| -rw-r--r-- | Documentation/w1/slaves/w1_ds2413.rst | 59 | ||||
| -rw-r--r-- | Documentation/w1/slaves/w1_ds2423.rst | 54 | ||||
| -rw-r--r-- | Documentation/w1/slaves/w1_ds2438.rst | 86 | ||||
| -rw-r--r-- | Documentation/w1/slaves/w1_ds28e04.rst | 41 | ||||
| -rw-r--r-- | Documentation/w1/slaves/w1_ds28e17.rst | 72 | ||||
| -rw-r--r-- | Documentation/w1/slaves/w1_therm.rst | 144 |
8 files changed, 499 insertions, 0 deletions
diff --git a/Documentation/w1/slaves/index.rst b/Documentation/w1/slaves/index.rst new file mode 100644 index 000000000..d0697b202 --- /dev/null +++ b/Documentation/w1/slaves/index.rst @@ -0,0 +1,16 @@ +. SPDX-License-Identifier: GPL-2.0 + +==================== +1-wire Slave Drivers +==================== + +.. toctree:: + :maxdepth: 1 + + w1_ds2406 + w1_ds2413 + w1_ds2423 + w1_ds2438 + w1_ds28e04 + w1_ds28e17 + w1_therm diff --git a/Documentation/w1/slaves/w1_ds2406.rst b/Documentation/w1/slaves/w1_ds2406.rst new file mode 100644 index 000000000..d3e682660 --- /dev/null +++ b/Documentation/w1/slaves/w1_ds2406.rst @@ -0,0 +1,27 @@ +======================= +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/Documentation/w1/slaves/w1_ds2413.rst b/Documentation/w1/slaves/w1_ds2413.rst new file mode 100644 index 000000000..c15bb5b91 --- /dev/null +++ b/Documentation/w1/slaves/w1_ds2413.rst @@ -0,0 +1,59 @@ +======================= +Kernel driver w1_ds2413 +======================= + +Supported chips: + + * Maxim DS2413 1-Wire Dual Channel Addressable Switch + +supported family codes: + + ================ ==== + W1_FAMILY_DS2413 0x3A + ================ ==== + +Author: Mariusz Bialonczyk <manio@skyboo.net> + +Description +----------- + +The DS2413 chip has two open-drain outputs (PIO A and PIO B). +Support is provided through the sysfs files "output" and "state". + +Reading state +------------- +The "state" file provides one-byte value which is in the same format as for +the chip PIO_ACCESS_READ command (refer the datasheet for details): + +======== ============================================================= +Bit 0: PIOA Pin State +Bit 1: PIOA Output Latch State +Bit 2: PIOB Pin State +Bit 3: PIOB Output Latch State +Bit 4-7: Complement of Bit 3 to Bit 0 (verified by the kernel module) +======== ============================================================= + +This file is readonly. + +Writing output +-------------- +You can set the PIO pins using the "output" file. +It is writable, you can write one-byte value to this sysfs file. +Similarly the byte format is the same as for the PIO_ACCESS_WRITE command: + +======== ====================================== +Bit 0: PIOA +Bit 1: PIOB +Bit 2-7: No matter (driver will set it to "1"s) +======== ====================================== + + +The chip has some kind of basic protection against transmission errors. +When reading the state, there is a four complement bits. +The driver is checking this complement, and when it is wrong then it is +returning I/O error. + +When writing output, the master must repeat the PIO Output Data byte in +its inverted form and it is waiting for a confirmation. +If the write is unsuccessful for three times, the write also returns +I/O error. diff --git a/Documentation/w1/slaves/w1_ds2423.rst b/Documentation/w1/slaves/w1_ds2423.rst new file mode 100644 index 000000000..755d659ad --- /dev/null +++ b/Documentation/w1/slaves/w1_ds2423.rst @@ -0,0 +1,54 @@ +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/Documentation/w1/slaves/w1_ds2438.rst b/Documentation/w1/slaves/w1_ds2438.rst new file mode 100644 index 000000000..4fa671fbc --- /dev/null +++ b/Documentation/w1/slaves/w1_ds2438.rst @@ -0,0 +1,86 @@ +Kernel driver w1_ds2438 +======================= + +Supported chips: + + * Maxim DS2438 Smart Battery Monitor + +supported family codes: + ================ ==== + W1_FAMILY_DS2438 0x26 + ================ ==== + +Author: Mariusz Bialonczyk <manio@skyboo.net> + +Description +----------- + +The DS2438 chip provides several functions that are desirable to carry in +a battery pack. It also has a 40 bytes of nonvolatile EEPROM. +Because the ability of temperature, current and voltage measurement, the chip +is also often used in weather stations and applications such as: rain gauge, +wind speed/direction measuring, humidity sensing, etc. + +Current support is provided through the following sysfs files (all files +except "iad" and "offset" are readonly): + +"iad" +----- +This file controls the 'Current A/D Control Bit' (IAD) in the +Status/Configuration Register. +Writing a zero value will clear the IAD bit and disables the current +measurements. +Writing value "1" is setting the IAD bit (enables the measurements). +The IAD bit is enabled by default in the DS2438. + +When writing to sysfs file bits 2-7 are ignored, so it's safe to write ASCII. +An I/O error is returned when there is a problem setting the new value. + +"page0" +------- +This file provides full 8 bytes of the chip Page 0 (00h). +This page contains the most frequently accessed information of the DS2438. +Internally when this file is read, the additional CRC byte is also obtained +from the slave device. If it is correct, the 8 bytes page data are passed +to userspace, otherwise an I/O error is returned. + +"page1" +------- +This file provides full 8 bytes of the chip Page 1 (01h). +This page contains the ICA, elapsed time meter and current offset data of the DS2438. +Internally when this file is read, the additional CRC byte is also obtained +from the slave device. If it is correct, the 8 bytes page data are passed +to userspace, otherwise an I/O error is returned. + +"offset" +-------- +This file controls the 2-byte Offset Register of the chip. +Writing a 2-byte value will change the Offset Register, which changes the +current measurement done by the chip. Changing this register to the two's complement +of the current register while forcing zero current through the load will calibrate +the chip, canceling offset errors in the current ADC. + + +"temperature" +------------- +Opening and reading this file initiates the CONVERT_T (temperature conversion) +command of the chip, afterwards the temperature is read from the device +registers and provided as an ASCII decimal value. + +Important: The returned value has to be divided by 256 to get a real +temperature in degrees Celsius. + +"vad", "vdd" +------------ +Opening and reading this file initiates the CONVERT_V (voltage conversion) +command of the chip. + +Depending on a sysfs filename a different input for the A/D will be selected: + +vad: + general purpose A/D input (VAD) +vdd: + battery input (VDD) + +After the voltage conversion the value is returned as decimal ASCII. +Note: To get a volts the value has to be divided by 100. diff --git a/Documentation/w1/slaves/w1_ds28e04.rst b/Documentation/w1/slaves/w1_ds28e04.rst new file mode 100644 index 000000000..b12b11889 --- /dev/null +++ b/Documentation/w1/slaves/w1_ds28e04.rst @@ -0,0 +1,41 @@ +======================== +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/Documentation/w1/slaves/w1_ds28e17.rst b/Documentation/w1/slaves/w1_ds28e17.rst new file mode 100644 index 000000000..e2d9f96d8 --- /dev/null +++ b/Documentation/w1/slaves/w1_ds28e17.rst @@ -0,0 +1,72 @@ +======================== +Kernel driver w1_ds28e17 +======================== + +Supported chips: + + * Maxim DS28E17 1-Wire-to-I2C Master Bridge + +supported family codes: + + ================= ==== + W1_FAMILY_DS28E17 0x19 + ================= ==== + +Author: Jan Kandziora <jjj@gmx.de> + + +Description +----------- +The DS28E17 is a Onewire slave device which acts as an I2C bus master. + +This driver creates a new I2C bus for any DS28E17 device detected. I2C buses +come and go as the DS28E17 devices come and go. I2C slave devices connected to +a DS28E17 can be accessed by the kernel or userspace tools as if they were +connected to a "native" I2C bus master. + + +An udev rule like the following:: + + SUBSYSTEM=="i2c-dev", KERNEL=="i2c-[0-9]*", ATTRS{name}=="w1-19-*", \ + SYMLINK+="i2c-$attr{name}" + +may be used to create stable /dev/i2c- entries based on the unique id of the +DS28E17 chip. + + +Driver parameters are: + +speed: + This sets up the default I2C speed a DS28E17 get configured for as soon + it is connected. The power-on default of the DS28E17 is 400kBaud, but + chips may come and go on the Onewire bus without being de-powered and + as soon the "w1_ds28e17" driver notices a freshly connected, or + reconnected DS28E17 device on the Onewire bus, it will re-apply this + setting. + + Valid values are 100, 400, 900 [kBaud]. Any other value means to leave + alone the current DS28E17 setting on detect. The default value is 100. + +stretch: + This sets up the default stretch value used for freshly connected + DS28E17 devices. It is a multiplier used on the calculation of the busy + wait time for an I2C transfer. This is to account for I2C slave devices + which make heavy use of the I2C clock stretching feature and thus, the + needed timeout cannot be pre-calculated correctly. As the w1_ds28e17 + driver checks the DS28E17's busy flag in a loop after the precalculated + wait time, it should be hardly needed to tweak this setting. + + Leave it at 1 unless you get ETIMEDOUT errors and a "w1_slave_driver + 19-00000002dbd8: busy timeout" in the kernel log. + + Valid values are 1 to 9. The default is 1. + + +The driver creates sysfs files /sys/bus/w1/devices/19-<id>/speed and +/sys/bus/w1/devices/19-<id>/stretch for each device, preloaded with the default +settings from the driver parameters. They may be changed anytime. In addition a +directory /sys/bus/w1/devices/19-<id>/i2c-<nnn> for the I2C bus master sysfs +structure is created. + + +See https://github.com/ianka/w1_ds28e17 for even more information. diff --git a/Documentation/w1/slaves/w1_therm.rst b/Documentation/w1/slaves/w1_therm.rst new file mode 100644 index 000000000..6aec04dd0 --- /dev/null +++ b/Documentation/w1/slaves/w1_therm.rst @@ -0,0 +1,144 @@ +====================== +Kernel driver w1_therm +====================== + +Supported chips: + + * Maxim ds18*20 based temperature sensors. + * Maxim ds1825 based temperature sensors. + * GXCAS GX20MH01 temperature sensor. + * Maxim MAX31850 thermoelement interface. + +Author: Evgeniy Polyakov <johnpol@2ka.mipt.ru> + + +Description +----------- + +w1_therm provides basic temperature conversion for ds18*20, ds28ea00, GX20MH01 +and MAX31850 devices. + +Supported family codes: + +==================== ==== +W1_THERM_DS18S20 0x10 +W1_THERM_DS1822 0x22 +W1_THERM_DS18B20 0x28 +W1_THERM_DS1825 0x3B +W1_THERM_DS28EA00 0x42 +==================== ==== + +Support is provided through the sysfs entry ``w1_slave``. 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=. + +Alternatively, temperature can be read using ``temperature`` sysfs, it +returns only the temperature in millidegrees Centigrade. + +A bulk read of all devices on the bus could be done writing ``trigger`` +to ``therm_bulk_read`` entry at w1_bus_master level. This will +send the convert command to all devices on the bus, and if parasite +powered devices are detected on the bus (and strong pullup is enabled +in the module), it will drive the line high during the longer conversion +time required by parasited powered device on the line. Reading +``therm_bulk_read`` will return 0 if no bulk conversion pending, +-1 if at least one sensor still in conversion, 1 if conversion is complete +but at least one sensor value has not been read yet. Result temperature is +then accessed by reading the ``temperature`` entry of each device, which +may return empty if conversion is still in progress. Note that if a bulk +read is sent but one sensor is not read immediately, the next access to +``temperature`` on this device will return the temperature measured at the +time of issue of the bulk read command (not the current temperature). + +A strong pullup will be applied during the conversion if required. + +``conv_time`` is used to get current conversion time (read), and +adjust it (write). A temperature conversion time depends on the device type and +its current resolution. Default conversion time is set by the driver according +to the device datasheet. A conversion time for many original device clones +deviate from datasheet specs. There are three options: 1) manually set the +correct conversion time by writing a value in milliseconds to ``conv_time``; 2) +auto measure and set a conversion time by writing ``1`` to +``conv_time``; 3) use ``features`` to enable poll for conversion +completion. Options 2, 3 can't be used in parasite power mode. To get back to +the default conversion time write ``0`` to ``conv_time``. + +Writing a resolution value (in bits) to ``w1_slave`` will change the +precision of the sensor for the next readings. Allowed resolutions are defined by +the sensor. Resolution is reset when the sensor gets power-cycled. + +To store the current resolution in EEPROM, write ``0`` to ``w1_slave``. +Since the EEPROM has a limited amount of writes (>50k), this command should be +used wisely. + +Alternatively, resolution can be read or written using the dedicated +``resolution`` entry on each device, if supported by the sensor. + +Some non-genuine DS18B20 chips are fixed in 12-bit mode only, so the actual +resolution is read back from the chip and verified. + +Note: Changing the resolution reverts the conversion time to default. + +The write-only sysfs entry ``eeprom_cmd`` is an alternative for EEPROM operations. +Write ``save`` to save device RAM to EEPROM. Write ``restore`` to restore EEPROM +data in device RAM. + +``ext_power`` entry allows checking the power state of each device. Reads +``0`` if the device is parasite powered, ``1`` if the device is externally powered. + +Sysfs ``alarms`` allow read or write TH and TL (Temperature High an Low) alarms. +Values shall be space separated and in the device range (typical -55 degC +to 125 degC). Values are integer as they are store in a 8bit register in +the device. Lowest value is automatically put to TL. Once set, alarms could +be search at master level. + +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. + +The DS28EA00 provides an additional two pins for implementing a sequence +detection algorithm. This feature allows you to determine the physical +location of the chip in the 1-wire bus without needing pre-existing +knowledge of the bus ordering. Support is provided through the sysfs +``w1_seq``. The file will contain a single line with an integer value +representing the device index in the bus starting at 0. + +``features`` sysfs entry controls optional driver settings per device. +Insufficient power in parasite mode, line noise and insufficient conversion +time may lead to conversion failure. Original DS18B20 and some clones allow for +detection of invalid conversion. Write bit mask ``1`` to ``features`` to enable +checking the conversion success. If byte 6 of scratchpad memory is 0xC after +conversion and temperature reads 85.00 (powerup value) or 127.94 (insufficient +power), the driver returns a conversion error. Bit mask ``2`` enables poll for +conversion completion (normal power only) by generating read cycles on the bus +after conversion starts. In parasite power mode this feature is not available. +Feature bit masks may be combined (OR). More details in +Documentation/ABI/testing/sysfs-driver-w1_therm + +GX20MH01 device shares family number 0x28 with DS18*20. The device is generally +compatible with DS18B20. Added are lowest 2\ :sup:`-5`, 2\ :sup:`-6` temperature +bits in Config register; R2 bit in Config register enabling 13 and 14 bit +resolutions. The device is powered up in 14-bit resolution mode. The conversion +times specified in the datasheet are too low and have to be increased. The +device supports driver features ``1`` and ``2``. + +MAX31850 device shares family number 0x3B with DS1825. The device is generally +compatible with DS1825. The higher 4 bits of Config register read all 1, +indicating 15, but the device is always operating in 14-bit resolution mode. |