@@ -27,75 +27,72 @@ W1_THERM_DS1825 0x3B
2727W1_THERM_DS28EA00 0x42
2828==================== ====
2929
30- Support is provided through the sysfs w1_slave file . Each open and
31- read sequence will initiate a temperature conversion then provide two
30+ Support is provided through the sysfs entry `` w1_slave `` . Each open and
31+ read sequence will initiate a temperature conversion, then provide two
3232lines of ASCII output. The first line contains the nine hex bytes
3333read along with a calculated crc value and YES or NO if it matched.
3434If the crc matched the returned values are retained. The second line
3535displays the retained values along with a temperature in millidegrees
3636Centigrade after t=.
3737
38- Alternatively, temperature can be read using temperature sysfs, it
39- return only temperature in millidegrees Centigrade.
38+ Alternatively, temperature can be read using `` temperature `` sysfs, it
39+ returns only the temperature in millidegrees Centigrade.
4040
41- A bulk read of all devices on the bus could be done writing ' trigger'
42- in the therm_bulk_read sysfs entry at w1_bus_master level. This will
43- sent the convert command on all devices on the bus, and if parasite
44- powered devices are detected on the bus (and strong pullup is enable
41+ A bulk read of all devices on the bus could be done writing `` trigger ``
42+ to `` therm_bulk_read `` entry at w1_bus_master level. This will
43+ send the convert command to all devices on the bus, and if parasite
44+ powered devices are detected on the bus (and strong pullup is enabled
4545in the module), it will drive the line high during the longer conversion
4646time required by parasited powered device on the line. Reading
47- therm_bulk_read will return 0 if no bulk conversion pending,
47+ `` therm_bulk_read `` will return 0 if no bulk conversion pending,
4848-1 if at least one sensor still in conversion, 1 if conversion is complete
4949but at least one sensor value has not been read yet. Result temperature is
50- then accessed by reading the temperature sysfs entry of each device, which
50+ then accessed by reading the `` temperature `` entry of each device, which
5151may return empty if conversion is still in progress. Note that if a bulk
5252read is sent but one sensor is not read immediately, the next access to
53- temperature on this device will return the temperature measured at the
53+ `` temperature `` on this device will return the temperature measured at the
5454time of issue of the bulk read command (not the current temperature).
5555
5656A strong pullup will be applied during the conversion if required.
5757
58- ``conv_time `` sysfs entry is used to get current conversion time (read), and
58+ ``conv_time `` is used to get current conversion time (read), and
5959adjust it (write). A temperature conversion time depends on the device type and
6060it's current resolution. Default conversion time is set by the driver according
6161to the device datasheet. A conversion time for many original device clones
6262deviate from datasheet specs. There are three options: 1) manually set the
6363correct conversion time by writing a value in milliseconds to ``conv_time ``; 2)
6464auto measure and set a conversion time by writing ``1 `` to
65- ``conv_time ``; 3) use ``features `` entry to enable poll for conversion
65+ ``conv_time ``; 3) use ``features `` to enable poll for conversion
6666completion. Options 2, 3 can't be used in parasite power mode. To get back to
6767the default conversion time write ``0 `` to ``conv_time ``.
6868
69- Writing a value between 9 and 12 to the sysfs w1_slave file will change the
70- precision of the sensor for the next readings. This value is in (volatile)
71- SRAM, so it is reset when the sensor gets power-cycled.
69+ Writing a resolution value (in bits) to `` w1_slave `` will change the
70+ precision of the sensor for the next readings. Allowed resolutions are defined by
71+ the sensor. Resolution is reset when the sensor gets power-cycled.
7272
73- To store the current precision configuration into EEPROM, the value 0
74- has to be written to the sysfs w1_slave file. Since the EEPROM has a limited
75- amount of writes (>50k), this command should be used wisely.
73+ To store the current resolution in EEPROM, write `` 0 `` to `` w1_slave ``.
74+ Since the EEPROM has a limited amount of writes (>50k), this command should be
75+ used wisely.
7676
77- Alternatively, resolution can be set or read (value from 9 to 12) using the
78- dedicated resolution sysfs entry on each device. This sysfs entry is not present
79- for devices not supporting this feature.
77+ Alternatively, resolution can be read or written using the dedicated
78+ ``resolution `` entry on each device, if supported by the sensor.
8079
81- Some non-genuine DS18B20 chips are
82- fixed in 12-bit mode only, so the actual resolution is read back from the chip
83- and verified by the driver.
80+ Some non-genuine DS18B20 chips are fixed in 12-bit mode only, so the actual
81+ resolution is read back from the chip and verified.
8482
8583Note: Changing the resolution reverts the conversion time to default.
8684
87- The write-only sysfs entry eeprom is an alternative for EEPROM operations:
88- * ' save': will save device RAM to EEPROM
89- * 'restore': will restore EEPROM data in device RAM.
85+ The write-only sysfs entry `` eeprom `` is an alternative for EEPROM operations.
86+ Write `` save `` to save device RAM to EEPROM. Write `` restore `` to restore EEPROM
87+ data in device RAM.
9088
91- ext_power syfs entry allow tho check the power status of each device.
92- * '0': device parasite powered
93- * '1': device externally powered
89+ ``ext_power `` entry allows checking the power state of each device. Reads
90+ ``0 `` if the device is parasite powered, ``1 `` if the device is externally powered.
9491
95- sysfs alarms allow read or write TH and TL (Temperature High an Low) alarms.
92+ Sysfs `` alarms `` allow read or write TH and TL (Temperature High an Low) alarms.
9693Values shall be space separated and in the device range (typical -55 degC
9794to 125 degC). Values are integer as they are store in a 8bit register in
98- the device. Lowest value is automatically put to TL.Once set, alarms could
95+ the device. Lowest value is automatically put to TL. Once set, alarms could
9996be search at master level.
10097
10198The 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
119116detection algorithm. This feature allows you to determine the physical
120117location of the chip in the 1-wire bus without needing pre-existing
121118knowledge of the bus ordering. Support is provided through the sysfs
122- w1_seq file. The file will contain a single line with an integer value
119+ `` w1_seq ``. The file will contain a single line with an integer value
123120representing the device index in the bus starting at 0.
124121
125122``features `` sysfs entry controls optional driver settings per device.
126- Insufficient power in parasite mode, line noise and insufficient conversion time
127- may lead to conversion failure. Original DS18B20 and some clones allow for
123+ Insufficient power in parasite mode, line noise and insufficient conversion
124+ time may lead to conversion failure. Original DS18B20 and some clones allow for
128125detection of invalid conversion. Write bit mask ``1 `` to ``features `` to enable
129126checking the conversion success. If byte 6 of scratchpad memory is 0xC after
130127conversion and temperature reads 85.00 (powerup value) or 127.94 (insufficient
131128power), the driver returns a conversion error. Bit mask ``2 `` enables poll for
132129conversion completion (normal power only) by generating read cycles on the bus
133130after conversion starts. In parasite power mode this feature is not available.
134- Feature bit masks may be combined (OR). See accompanying sysfs documentation:
135- :ref: ` Documentation/w1/slaves/ w1_therm.rst < w1_therm >`
131+ Feature bit masks may be combined (OR). More details in
132+ Documentation/ABI/testing/sysfs-driver- w1_therm
136133
137134GX20MH01 device shares family number 0x28 with DS18*20. The device is generally
138- compatible with DS18B20. Added are lowest 2^-5 , 2^-6 temperature bits in Config
139- register; R2 bit in Config register enabling 13 and 14 bit resolutions. The
140- device is powered up in 14-bit resolution mode. The conversion times specified
141- in the datasheet are too low and have to be increased. The device supports
142- driver features ``1 `` and ``2 ``.
135+ compatible with DS18B20. Added are lowest 2\ :sup: `-5` , 2\ :sup: `-6` temperature
136+ bits in Config register; R2 bit in Config register enabling 13 and 14 bit
137+ resolutions. The device is powered up in 14-bit resolution mode. The conversion
138+ times specified in the datasheet are too low and have to be increased. The
139+ device supports driver features ``1 `` and ``2 ``.
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