191 строка
6.3 KiB
Plaintext
191 строка
6.3 KiB
Plaintext
What: /sys/bus/w1/devices/.../alarms
|
|
Date: May 2020
|
|
Contact: Akira Shimahara <akira215corp@gmail.com>
|
|
Description:
|
|
(RW) 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), if not values will be trimmed
|
|
to device min/max capabilities. Values are integer as they are
|
|
stored in a 8bit register in the device. Lowest value is
|
|
automatically put to TL. Once set, alarms could be search at
|
|
master level, refer to Documentation/w1/w1-generic.rst for
|
|
detailed information
|
|
Users: any user space application which wants to communicate with
|
|
w1_term device
|
|
|
|
|
|
What: /sys/bus/w1/devices/.../eeprom_cmd
|
|
Date: May 2020
|
|
Contact: Akira Shimahara <akira215corp@gmail.com>
|
|
Description:
|
|
(WO) writing that file will either trigger a save of the
|
|
device data to its embedded EEPROM, either restore data
|
|
embedded in device EEPROM. Be aware that devices support
|
|
limited EEPROM writing cycles (typical 50k)
|
|
|
|
* 'save': save device RAM to EEPROM
|
|
* 'restore': restore EEPROM data in device RAM
|
|
|
|
Users: any user space application which wants to communicate with
|
|
w1_term device
|
|
|
|
|
|
What: /sys/bus/w1/devices/.../ext_power
|
|
Date: May 2020
|
|
Contact: Akira Shimahara <akira215corp@gmail.com>
|
|
Description:
|
|
(RO) return the power status by asking the device
|
|
|
|
* '0': device parasite powered
|
|
* '1': device externally powered
|
|
* '-xx': xx is kernel error when reading power status
|
|
|
|
Users: any user space application which wants to communicate with
|
|
w1_term device
|
|
|
|
|
|
What: /sys/bus/w1/devices/.../resolution
|
|
Date: May 2020
|
|
Contact: Akira Shimahara <akira215corp@gmail.com>
|
|
Description:
|
|
(RW) get or set the device resolution (on supported devices,
|
|
if not, this entry is not present). Note that the resolution
|
|
will be changed only in device RAM, so it will be cleared when
|
|
power is lost. Trigger a 'save' to EEPROM command to keep
|
|
values after power-on. Read or write are :
|
|
|
|
* '9..14': device resolution in bit
|
|
or resolution to set in bit
|
|
* '-xx': xx is kernel error when reading the resolution
|
|
* Anything else: do nothing
|
|
|
|
Some DS18B20 clones are fixed in 12-bit resolution, so the
|
|
actual resolution is read back from the chip and verified. Error
|
|
is reported if the results differ.
|
|
Users: any user space application which wants to communicate with
|
|
w1_term device
|
|
|
|
|
|
What: /sys/bus/w1/devices/.../temperature
|
|
Date: May 2020
|
|
Contact: Akira Shimahara <akira215corp@gmail.com>
|
|
Description:
|
|
(RO) return the temperature in 1/1000 degC.
|
|
|
|
* If a bulk read has been triggered, it will directly
|
|
return the temperature computed when the bulk read
|
|
occurred, if available. If not yet available, nothing
|
|
is returned (a debug kernel message is sent), you
|
|
should retry later on.
|
|
* If no bulk read has been triggered, it will trigger
|
|
a conversion and send the result. Note that the
|
|
conversion duration depend on the resolution (if
|
|
device support this feature). It takes 94ms in 9bits
|
|
resolution, 750ms for 12bits.
|
|
|
|
Users: any user space application which wants to communicate with
|
|
w1_term device
|
|
|
|
|
|
What: /sys/bus/w1/devices/.../w1_slave
|
|
Date: May 2020
|
|
Contact: Akira Shimahara <akira215corp@gmail.com>
|
|
Description:
|
|
(RW) return the temperature in 1/1000 degC.
|
|
*read*: return 2 lines with the hexa output data sent on the
|
|
bus, return the CRC check and temperature in 1/1000 degC
|
|
*write*:
|
|
|
|
* '0' : save the 2 or 3 bytes to the device EEPROM
|
|
(i.e. TH, TL and config register)
|
|
* '9..14' : set the device resolution in RAM
|
|
(if supported)
|
|
* Anything else: do nothing
|
|
|
|
refer to Documentation/w1/slaves/w1_therm.rst for detailed
|
|
information.
|
|
Users: any user space application which wants to communicate with
|
|
w1_term device
|
|
|
|
|
|
What: /sys/bus/w1/devices/w1_bus_masterXX/therm_bulk_read
|
|
Date: May 2020
|
|
Contact: Akira Shimahara <akira215corp@gmail.com>
|
|
Description:
|
|
(RW) trigger a bulk read conversion. read the status
|
|
|
|
*read*:
|
|
* '-1':
|
|
conversion in progress on at least 1 sensor
|
|
* '1' :
|
|
conversion complete but at least one sensor
|
|
value has not been read yet
|
|
* '0' :
|
|
no bulk operation. Reading temperature will
|
|
trigger a conversion on each device
|
|
|
|
*write*:
|
|
'trigger': trigger a bulk read on all supporting
|
|
devices on the bus
|
|
|
|
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).
|
|
Users: any user space application which wants to communicate with
|
|
w1_term device
|
|
|
|
|
|
What: /sys/bus/w1/devices/.../conv_time
|
|
Date: July 2020
|
|
Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
|
|
Description:
|
|
(RW) Get, set, or measure a temperature conversion time. The
|
|
setting remains active until a resolution change. Then it is
|
|
reset to default (datasheet) conversion time for a new
|
|
resolution.
|
|
|
|
*read*:
|
|
Actual conversion time in milliseconds.
|
|
|
|
*write*:
|
|
* '0':
|
|
Set the default conversion time from the datasheet.
|
|
* '1':
|
|
Measure and set the conversion time. Make a single
|
|
temperature conversion, measure an actual value.
|
|
Increase it by 20% for temperature range. A new
|
|
conversion time can be obtained by reading this
|
|
same attribute.
|
|
* other positive value:
|
|
Set the conversion time in milliseconds.
|
|
|
|
Users: An application using the w1_term device
|
|
|
|
|
|
What: /sys/bus/w1/devices/.../features
|
|
Date: July 2020
|
|
Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
|
|
Description:
|
|
(RW) Control optional driver settings.
|
|
Bit masks to read/write (bitwise OR):
|
|
|
|
== ============================================================
|
|
1 Enable check for conversion success. If byte 6 of
|
|
scratchpad memory is 0xC after conversion, and
|
|
temperature reads 85.00 (powerup value) or 127.94
|
|
(insufficient power) - return a conversion error.
|
|
|
|
2 Enable poll for conversion completion. Generate read cycles
|
|
after the conversion start and wait for 1's. In parasite
|
|
power mode this feature is not available.
|
|
== ============================================================
|
|
|
|
*read*:
|
|
Currently selected features.
|
|
|
|
*write*:
|
|
Select features.
|
|
|
|
Users: An application using the w1_term device
|