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..12': 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 56Users: any user space application which wants to communicate with 57 w1_term device 58 59 60What: /sys/bus/w1/devices/.../temperature 61Date: May 2020 62Contact: Akira Shimahara <akira215corp@gmail.com> 63Description: 64 (RO) return the temperature in 1/1000 degC. 65 * If a bulk read has been triggered, it will directly 66 return the temperature computed when the bulk read 67 occurred, if available. If not yet available, nothing 68 is returned (a debug kernel message is sent), you 69 should retry later on. 70 * If no bulk read has been triggered, it will trigger 71 a conversion and send the result. Note that the 72 conversion duration depend on the resolution (if 73 device support this feature). It takes 94ms in 9bits 74 resolution, 750ms for 12bits. 75Users: any user space application which wants to communicate with 76 w1_term device 77 78 79What: /sys/bus/w1/devices/.../w1_slave 80Date: May 2020 81Contact: Akira Shimahara <akira215corp@gmail.com> 82Description: 83 (RW) return the temperature in 1/1000 degC. 84 *read*: return 2 lines with the hexa output data sent on the 85 bus, return the CRC check and temperature in 1/1000 degC 86 *write* : 87 * '0' : save the 2 or 3 bytes to the device EEPROM 88 (i.e. TH, TL and config register) 89 * '9..12' : set the device resolution in RAM 90 (if supported) 91 * Anything else: do nothing 92 refer to Documentation/w1/slaves/w1_therm.rst for detailed 93 information. 94Users: any user space application which wants to communicate with 95 w1_term device 96 97 98What: /sys/bus/w1/devices/w1_bus_masterXX/therm_bulk_read 99Date: May 2020 100Contact: Akira Shimahara <akira215corp@gmail.com> 101Description: 102 (RW) trigger a bulk read conversion. read the status 103 *read*: 104 * '-1': conversion in progress on at least 1 sensor 105 * '1' : conversion complete but at least one sensor 106 value has not been read yet 107 * '0' : no bulk operation. Reading temperature will 108 trigger a conversion on each device 109 *write*: 'trigger': trigger a bulk read on all supporting 110 devices on the bus 111 Note that if a bulk read is sent but one sensor is not read 112 immediately, the next access to temperature on this device 113 will return the temperature measured at the time of issue 114 of the bulk read command (not the current temperature). 115Users: any user space application which wants to communicate with 116 w1_term device 117