1 What: /sys/bus/w1/devices/.../alarms 1 What: /sys/bus/w1/devices/.../alarms
2 Date: May 2020 2 Date: May 2020
3 Contact: Akira Shimahara <akira215corp@g 3 Contact: Akira Shimahara <akira215corp@gmail.com>
4 Description: 4 Description:
5 (RW) read or write TH and TL ( 5 (RW) read or write TH and TL (Temperature High an Low) alarms.
6 Values shall be space separate 6 Values shall be space separated and in the device range
7 (typical -55 degC to 125 degC) 7 (typical -55 degC to 125 degC), if not values will be trimmed
8 to device min/max capabilities 8 to device min/max capabilities. Values are integer as they are
9 stored in a 8bit register in t 9 stored in a 8bit register in the device. Lowest value is
10 automatically put to TL. Once 10 automatically put to TL. Once set, alarms could be search at
11 master level, refer to Documen 11 master level, refer to Documentation/w1/w1-generic.rst for
12 detailed information 12 detailed information
13 Users: any user space application whi 13 Users: any user space application which wants to communicate with
14 w1_term device 14 w1_term device
15 15
16 16
17 What: /sys/bus/w1/devices/.../eeprom 17 What: /sys/bus/w1/devices/.../eeprom_cmd
18 Date: May 2020 18 Date: May 2020
19 Contact: Akira Shimahara <akira215corp@g 19 Contact: Akira Shimahara <akira215corp@gmail.com>
20 Description: 20 Description:
21 (WO) writing that file will ei 21 (WO) writing that file will either trigger a save of the
22 device data to its embedded EE 22 device data to its embedded EEPROM, either restore data
23 embedded in device EEPROM. Be 23 embedded in device EEPROM. Be aware that devices support
24 limited EEPROM writing cycles 24 limited EEPROM writing cycles (typical 50k)
25 25
26 * 'save': save device 26 * 'save': save device RAM to EEPROM
27 * 'restore': restore E 27 * 'restore': restore EEPROM data in device RAM
28 28
29 Users: any user space application whi 29 Users: any user space application which wants to communicate with
30 w1_term device 30 w1_term device
31 31
32 32
33 What: /sys/bus/w1/devices/.../ext_po 33 What: /sys/bus/w1/devices/.../ext_power
34 Date: May 2020 34 Date: May 2020
35 Contact: Akira Shimahara <akira215corp@g 35 Contact: Akira Shimahara <akira215corp@gmail.com>
36 Description: 36 Description:
37 (RO) return the power status b 37 (RO) return the power status by asking the device
38 38
39 * '0': device parasite 39 * '0': device parasite powered
40 * '1': device external 40 * '1': device externally powered
41 * '-xx': xx is kernel 41 * '-xx': xx is kernel error when reading power status
42 42
43 Users: any user space application whi 43 Users: any user space application which wants to communicate with
44 w1_term device 44 w1_term device
45 45
46 46
47 What: /sys/bus/w1/devices/.../resolu 47 What: /sys/bus/w1/devices/.../resolution
48 Date: May 2020 48 Date: May 2020
49 Contact: Akira Shimahara <akira215corp@g 49 Contact: Akira Shimahara <akira215corp@gmail.com>
50 Description: 50 Description:
51 (RW) get or set the device res 51 (RW) get or set the device resolution (on supported devices,
52 if not, this entry is not pres 52 if not, this entry is not present). Note that the resolution
53 will be changed only in device 53 will be changed only in device RAM, so it will be cleared when
54 power is lost. Trigger a 'save 54 power is lost. Trigger a 'save' to EEPROM command to keep
55 values after power-on. Read or 55 values after power-on. Read or write are :
56 56
57 * '9..14': device reso 57 * '9..14': device resolution in bit
58 or resolution to set 58 or resolution to set in bit
59 * '-xx': xx is kernel 59 * '-xx': xx is kernel error when reading the resolution
60 * Anything else: do no 60 * Anything else: do nothing
61 61
62 Some DS18B20 clones are fixed 62 Some DS18B20 clones are fixed in 12-bit resolution, so the
63 actual resolution is read back 63 actual resolution is read back from the chip and verified. Error
64 is reported if the results dif 64 is reported if the results differ.
65 Users: any user space application whi 65 Users: any user space application which wants to communicate with
66 w1_term device 66 w1_term device
67 67
68 68
69 What: /sys/bus/w1/devices/.../temper 69 What: /sys/bus/w1/devices/.../temperature
70 Date: May 2020 70 Date: May 2020
71 Contact: Akira Shimahara <akira215corp@g 71 Contact: Akira Shimahara <akira215corp@gmail.com>
72 Description: 72 Description:
73 (RO) return the temperature in 73 (RO) return the temperature in 1/1000 degC.
74 74
75 * If a bulk read has b 75 * If a bulk read has been triggered, it will directly
76 return the temperatu 76 return the temperature computed when the bulk read
77 occurred, if availab 77 occurred, if available. If not yet available, nothing
78 is returned (a debug 78 is returned (a debug kernel message is sent), you
79 should retry later o 79 should retry later on.
80 * If no bulk read has 80 * If no bulk read has been triggered, it will trigger
81 a conversion and sen 81 a conversion and send the result. Note that the
82 conversion duration 82 conversion duration depend on the resolution (if
83 device support this 83 device support this feature). It takes 94ms in 9bits
84 resolution, 750ms fo 84 resolution, 750ms for 12bits.
85 85
86 Users: any user space application whi 86 Users: any user space application which wants to communicate with
87 w1_term device 87 w1_term device
88 88
89 89
90 What: /sys/bus/w1/devices/.../w1_sla 90 What: /sys/bus/w1/devices/.../w1_slave
91 Date: May 2020 91 Date: May 2020
92 Contact: Akira Shimahara <akira215corp@g 92 Contact: Akira Shimahara <akira215corp@gmail.com>
93 Description: 93 Description:
94 (RW) return the temperature in 94 (RW) return the temperature in 1/1000 degC.
95 *read*: return 2 lines with th 95 *read*: return 2 lines with the hexa output data sent on the
96 bus, return the CRC check and 96 bus, return the CRC check and temperature in 1/1000 degC
97 *write*: 97 *write*:
98 98
99 * '0' : save the 2 or 99 * '0' : save the 2 or 3 bytes to the device EEPROM
100 (i.e. TH, TL and con 100 (i.e. TH, TL and config register)
101 * '9..14' : set the de 101 * '9..14' : set the device resolution in RAM
102 (if supported) 102 (if supported)
103 * Anything else: do no 103 * Anything else: do nothing
104 104
105 refer to Documentation/w1/slav 105 refer to Documentation/w1/slaves/w1_therm.rst for detailed
106 information. 106 information.
107 Users: any user space application whi 107 Users: any user space application which wants to communicate with
108 w1_term device 108 w1_term device
109 109
110 110
111 What: /sys/bus/w1/devices/w1_bus_mas 111 What: /sys/bus/w1/devices/w1_bus_masterXX/therm_bulk_read
112 Date: May 2020 112 Date: May 2020
113 Contact: Akira Shimahara <akira215corp@g 113 Contact: Akira Shimahara <akira215corp@gmail.com>
114 Description: 114 Description:
115 (RW) trigger a bulk read conve 115 (RW) trigger a bulk read conversion. read the status
116 116
117 *read*: 117 *read*:
118 * '-1': 118 * '-1':
119 conversion in 119 conversion in progress on at least 1 sensor
120 * '1' : 120 * '1' :
121 conversion com 121 conversion complete but at least one sensor
122 value has not 122 value has not been read yet
123 * '0' : 123 * '0' :
124 no bulk operat 124 no bulk operation. Reading temperature will
125 trigger a conv 125 trigger a conversion on each device
126 126
127 *write*: 127 *write*:
128 'trigger': trigger a b 128 'trigger': trigger a bulk read on all supporting
129 devices on the bus 129 devices on the bus
130 130
131 Note that if a bulk read is se 131 Note that if a bulk read is sent but one sensor is not read
132 immediately, the next access t 132 immediately, the next access to temperature on this device
133 will return the temperature me 133 will return the temperature measured at the time of issue
134 of the bulk read command (not 134 of the bulk read command (not the current temperature).
135 Users: any user space application whi 135 Users: any user space application which wants to communicate with
136 w1_term device 136 w1_term device
137 137
138 138
139 What: /sys/bus/w1/devices/.../conv_t 139 What: /sys/bus/w1/devices/.../conv_time
140 Date: July 2020 140 Date: July 2020
141 Contact: Ivan Zaentsev <ivan.zaentsev@wi 141 Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
142 Description: 142 Description:
143 (RW) Get, set, or measure a te 143 (RW) Get, set, or measure a temperature conversion time. The
144 setting remains active until a 144 setting remains active until a resolution change. Then it is
145 reset to default (datasheet) c 145 reset to default (datasheet) conversion time for a new
146 resolution. 146 resolution.
147 147
148 *read*: 148 *read*:
149 Actual conversion time 149 Actual conversion time in milliseconds.
150 150
151 *write*: 151 *write*:
152 * '0': 152 * '0':
153 Set the default c 153 Set the default conversion time from the datasheet.
154 * '1': 154 * '1':
155 Measure and set t 155 Measure and set the conversion time. Make a single
156 temperature conve 156 temperature conversion, measure an actual value.
157 Increase it by 20 157 Increase it by 20% for temperature range. A new
158 conversion time c 158 conversion time can be obtained by reading this
159 same attribute. 159 same attribute.
160 * other positive value 160 * other positive value:
161 Set the conversio 161 Set the conversion time in milliseconds.
162 162
163 Users: An application using the w1_te 163 Users: An application using the w1_term device
164 164
165 165
166 What: /sys/bus/w1/devices/.../featur 166 What: /sys/bus/w1/devices/.../features
167 Date: July 2020 167 Date: July 2020
168 Contact: Ivan Zaentsev <ivan.zaentsev@wi 168 Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru>
169 Description: 169 Description:
170 (RW) Control optional driver s 170 (RW) Control optional driver settings.
171 Bit masks to read/write (bitwi 171 Bit masks to read/write (bitwise OR):
172 172
173 == =========================== 173 == ============================================================
174 1 Enable check for conversion 174 1 Enable check for conversion success. If byte 6 of
175 scratchpad memory is 0xC af 175 scratchpad memory is 0xC after conversion, and
176 temperature reads 85.00 (po 176 temperature reads 85.00 (powerup value) or 127.94
177 (insufficient power) - retu 177 (insufficient power) - return a conversion error.
178 178
179 2 Enable poll for conversion 179 2 Enable poll for conversion completion. Generate read cycles
180 after the conversion start 180 after the conversion start and wait for 1's. In parasite
181 power mode this feature is 181 power mode this feature is not available.
182 == =========================== 182 == ============================================================
183 183
184 *read*: 184 *read*:
185 Currently selected feature 185 Currently selected features.
186 186
187 *write*: 187 *write*:
188 Select features. 188 Select features.
189 189
190 Users: An application using the w1_te 190 Users: An application using the w1_term device
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