diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-driver-w1_therm')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-driver-w1_therm | 51 |
1 files changed, 49 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-w1_therm b/Documentation/ABI/testing/sysfs-driver-w1_therm index 9b488c0afdfa..8873bbb075cb 100644 --- a/Documentation/ABI/testing/sysfs-driver-w1_therm +++ b/Documentation/ABI/testing/sysfs-driver-w1_therm @@ -49,10 +49,13 @@ Description: will be changed only in device RAM, so it will be cleared when power is lost. Trigger a 'save' to EEPROM command to keep values after power-on. Read or write are : - * '9..12': device resolution in bit + * '9..14': device resolution in bit or resolution to set in bit * '-xx': xx is kernel error when reading the resolution * Anything else: do nothing + Some DS18B20 clones are fixed in 12-bit resolution, so the + actual resolution is read back from the chip and verified. Error + is reported if the results differ. Users: any user space application which wants to communicate with w1_term device @@ -86,7 +89,7 @@ Description: *write* : * '0' : save the 2 or 3 bytes to the device EEPROM (i.e. TH, TL and config register) - * '9..12' : set the device resolution in RAM + * '9..14' : set the device resolution in RAM (if supported) * Anything else: do nothing refer to Documentation/w1/slaves/w1_therm.rst for detailed @@ -114,3 +117,47 @@ Description: of the bulk read command (not the current temperature). Users: any user space application which wants to communicate with w1_term device + + +What: /sys/bus/w1/devices/.../conv_time +Date: July 2020 +Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> +Description: + (RW) Get, set, or measure a temperature conversion time. The + setting remains active until a resolution change. Then it is + reset to default (datasheet) conversion time for a new + resolution. + + *read*: Actual conversion time in milliseconds. *write*: + '0': Set the default conversion time from the datasheet. + '1': Measure and set the conversion time. Make a single + temperature conversion, measure an actual value. + Increase it by 20% for temperature range. A new + conversion time can be obtained by reading this + same attribute. + other positive value: + Set the conversion time in milliseconds. + +Users: An application using the w1_term device + + +What: /sys/bus/w1/devices/.../features +Date: July 2020 +Contact: Ivan Zaentsev <ivan.zaentsev@wirenboard.ru> +Description: + (RW) Control optional driver settings. + Bit masks to read/write (bitwise OR): + + 1: Enable check for conversion success. If byte 6 of + scratchpad memory is 0xC after conversion, and + temperature reads 85.00 (powerup value) or 127.94 + (insufficient power) - return a conversion error. + + 2: Enable poll for conversion completion. Generate read cycles + after the conversion start and wait for 1's. In parasite + power mode this feature is not available. + + *read*: Currently selected features. + *write*: Select features. + +Users: An application using the w1_term device |