mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-23 22:00:51 +07:00
docs: w1: w1_therm: Fix broken xref, mistakes, clarify text
sysfs attribute names are mixed with the same normal text terms. Use ReST to distinguish. Fix typos and mistakes. Reported-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> Link: https://lore.kernel.org/r/20201008054259.5461-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
51fbad388c
commit
78eef5d952
@ -146,7 +146,7 @@ Date: July 2020
|
||||
Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
|
||||
Description:
|
||||
(RW) Control optional driver settings.
|
||||
Bit masks to read/write (logical OR):
|
||||
Bit masks to read/write (bitwise OR):
|
||||
|
||||
1: Enable check for conversion success. If byte 6 of
|
||||
scratchpad memory is 0xC after conversion, and
|
||||
@ -157,7 +157,7 @@ Description:
|
||||
after the conversion start and wait for 1's. In parasite
|
||||
power mode this feature is not available.
|
||||
|
||||
*read*: Currently selected features, bitwise OR.
|
||||
*write*: Select features, bitwise OR.
|
||||
*read*: Currently selected features.
|
||||
*write*: Select features.
|
||||
|
||||
Users: An application using the w1_term device
|
||||
|
@ -27,75 +27,72 @@ W1_THERM_DS1825 0x3B
|
||||
W1_THERM_DS28EA00 0x42
|
||||
==================== ====
|
||||
|
||||
Support is provided through the sysfs w1_slave file. Each open and
|
||||
read sequence will initiate a temperature conversion then provide two
|
||||
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
|
||||
return only temperature in millidegrees Centigrade.
|
||||
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'
|
||||
in the therm_bulk_read sysfs entry at w1_bus_master level. This will
|
||||
sent the convert command on all devices on the bus, and if parasite
|
||||
powered devices are detected on the bus (and strong pullup is enable
|
||||
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,
|
||||
``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 sysfs entry of each device, which
|
||||
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
|
||||
``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`` sysfs entry is used to get current conversion time (read), and
|
||||
``conv_time`` is used to get current conversion time (read), and
|
||||
adjust it (write). A temperature conversion time depends on the device type and
|
||||
it's 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`` entry to enable poll for conversion
|
||||
``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 value between 9 and 12 to the sysfs w1_slave file will change the
|
||||
precision of the sensor for the next readings. This value is in (volatile)
|
||||
SRAM, so it is reset when the sensor gets power-cycled.
|
||||
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 precision configuration into EEPROM, the value 0
|
||||
has to be written to the sysfs w1_slave file. Since the EEPROM has a limited
|
||||
amount of writes (>50k), this command should be used wisely.
|
||||
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 set or read (value from 9 to 12) using the
|
||||
dedicated resolution sysfs entry on each device. This sysfs entry is not present
|
||||
for devices not supporting this feature.
|
||||
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 by the driver.
|
||||
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 is an alternative for EEPROM operations:
|
||||
* 'save': will save device RAM to EEPROM
|
||||
* 'restore': will restore EEPROM data in device RAM.
|
||||
The write-only sysfs entry ``eeprom`` 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 syfs entry allow tho check the power status of each device.
|
||||
* '0': device parasite powered
|
||||
* '1': device externally powered
|
||||
``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.
|
||||
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
|
||||
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
|
||||
@ -119,24 +116,24 @@ 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 file. The file will contain a single line with an integer value
|
||||
``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
|
||||
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). See accompanying sysfs documentation:
|
||||
:ref:`Documentation/w1/slaves/w1_therm.rst <w1_therm>`
|
||||
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^-5, 2^-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``.
|
||||
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``.
|
||||
|
Loading…
Reference in New Issue
Block a user