1What:		/sys/bus/w1/devices/.../alarms
2Date:		May 2020
3Contact:	Akira Shimahara <akira215corp@gmail.com>
4Description:
5		(RW) read or write TH and TL (Temperature High an Low) alarms.
6		Values shall be space separated and in the device range
7		(typical -55 degC to 125 degC), if not values will be trimmed
8		to device min/max capabilities. Values are integer as they are
9		stored in a 8bit register in the device. Lowest value is
10		automatically put to TL. Once set, alarms could be search at
11		master level, refer to Documentation/w1/w1-generic.rst for
12		detailed information
13Users:		any user space application which wants to communicate with
14		w1_term device
15
16
17What:		/sys/bus/w1/devices/.../eeprom
18Date:		May 2020
19Contact:	Akira Shimahara <akira215corp@gmail.com>
20Description:
21		(WO) writing that file will either trigger a save of the
22		device data to its embedded EEPROM, either restore data
23		embedded in device EEPROM. Be aware that devices support
24		limited EEPROM writing cycles (typical 50k)
25			* 'save': save device RAM to EEPROM
26			* 'restore': restore EEPROM data in device RAM
27Users:		any user space application which wants to communicate with
28		w1_term device
29
30
31What:		/sys/bus/w1/devices/.../ext_power
32Date:		May 2020
33Contact:	Akira Shimahara <akira215corp@gmail.com>
34Description:
35		(RO) return the power status by asking the device
36			* '0': device parasite powered
37			* '1': device externally powered
38			* '-xx': xx is kernel error when reading power status
39Users:		any user space application which wants to communicate with
40		w1_term device
41
42
43What:		/sys/bus/w1/devices/.../resolution
44Date:		May 2020
45Contact:	Akira Shimahara <akira215corp@gmail.com>
46Description:
47		(RW) get or set the device resolution (on supported devices,
48		if not, this entry is not present). Note that the resolution
49		will be changed only in device RAM, so it will be cleared when
50		power is lost. Trigger a 'save' to EEPROM command to keep
51		values after power-on. Read or write are :
52			* '9..14': device resolution in bit
53			or resolution to set in bit
54			* '-xx': xx is kernel error when reading the resolution
55			* Anything else: do nothing
56		Some DS18B20 clones are fixed in 12-bit resolution, so the
57		actual resolution is read back from the chip and verified. Error
58		is reported if the results differ.
59Users:		any user space application which wants to communicate with
60		w1_term device
61
62
63What:		/sys/bus/w1/devices/.../temperature
64Date:		May 2020
65Contact:	Akira Shimahara <akira215corp@gmail.com>
66Description:
67		(RO) return the temperature in 1/1000 degC.
68			* If a bulk read has been triggered, it will directly
69			return the temperature computed when the bulk read
70			occurred, if available. If not yet available, nothing
71			is returned (a debug kernel message is sent), you
72			should retry later on.
73			* If no bulk read has been triggered, it will trigger
74			a conversion and send the result. Note that the
75			conversion duration depend on the resolution (if
76			device support this feature). It takes 94ms in 9bits
77			resolution, 750ms for 12bits.
78Users:		any user space application which wants to communicate with
79		w1_term device
80
81
82What:		/sys/bus/w1/devices/.../w1_slave
83Date:		May 2020
84Contact:	Akira Shimahara <akira215corp@gmail.com>
85Description:
86		(RW) return the temperature in 1/1000 degC.
87		*read*: return 2 lines with the hexa output data sent on the
88		bus, return the CRC check and temperature in 1/1000 degC
89		*write* :
90			* '0' : save the 2 or 3 bytes to the device EEPROM
91			(i.e. TH, TL and config register)
92			* '9..14' : set the device resolution in RAM
93			(if supported)
94			* Anything else: do nothing
95		refer to Documentation/w1/slaves/w1_therm.rst for detailed
96		information.
97Users:		any user space application which wants to communicate with
98		w1_term device
99
100
101What:		/sys/bus/w1/devices/w1_bus_masterXX/therm_bulk_read
102Date:		May 2020
103Contact:	Akira Shimahara <akira215corp@gmail.com>
104Description:
105		(RW) trigger a bulk read conversion. read the status
106		*read*:
107			* '-1': conversion in progress on at least 1 sensor
108			* '1' :	conversion complete but at least one sensor
109				value has not been read yet
110			* '0' :	no bulk operation. Reading temperature will
111				trigger a conversion on each device
112		*write*: 'trigger': trigger a bulk read on all supporting
113			devices on the bus
114		Note that if a bulk read is sent but one sensor is not read
115		immediately, the next access to temperature on this device
116		will return the temperature measured at the time of issue
117		of the bulk read command (not the current temperature).
118Users:		any user space application which wants to communicate with
119		w1_term device
120
121
122What:		/sys/bus/w1/devices/.../conv_time
123Date:		July 2020
124Contact:	Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
125Description:
126		(RW) Get, set, or measure a temperature conversion time. The
127		setting remains active until a resolution change. Then it is
128		reset to default (datasheet) conversion time for a new
129		resolution.
130
131		*read*: Actual conversion time in milliseconds. *write*:
132			'0': Set the default conversion time from the datasheet.
133			'1': Measure and set the conversion time. Make a single
134			     temperature conversion, measure an actual value.
135			     Increase it by 20% for temperature range. A new
136			     conversion time can be obtained by reading this
137			     same attribute.
138			other positive value:
139			     Set the conversion time in milliseconds.
140
141Users:		An application using the w1_term device
142
143
144What:		/sys/bus/w1/devices/.../features
145Date:		July 2020
146Contact:	Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
147Description:
148		(RW) Control optional driver settings.
149		Bit masks to read/write (bitwise OR):
150
151                1: Enable check for conversion success. If byte 6 of
152                   scratchpad memory is 0xC after conversion, and
153                   temperature reads 85.00 (powerup value) or 127.94
154                   (insufficient power) - return a conversion error.
155
156                2: Enable poll for conversion completion. Generate read cycles
157                   after the conversion start and wait for 1's. In parasite
158                   power mode this feature is not available.
159
160		*read*:  Currently selected features.
161		*write*: Select features.
162
163Users:		An application using the w1_term device
164