Support for software/virtual sensors

[aleksamagicka]

Track progress on this here instead of in #24, so we can merge parts of this more granularly when they're reverse engineered and/or implemented.

• Read and expose virtual sensors from the sensors report
  • D5 Next
  • Farbwerk 360
  • Octo
  • Quadro
  • Farbwerk
  • High Flow Next
  • Aquaero (supports "software" sensors from aquasuite)
  • Leakshield
• Implement writing to sysfs entries and saving them to the device (need to RE offsets/reports?)
  • D5 Next
  • Farbwerk 360
  • Octo
  • Quadro
  • Farbwerk
  • High Flow Next
  • Aquaero
  • Leakshield
• Explain/note everything in kernel and normal docs

It seems like virtual temp sensors expire on the device automatically after 10-15 seconds of no updates.

[aleksamagicka]

@dankamongmen Looking at the manual, the HFN has 8 software sensors available. Can you please RE their offset in the sensor report (the automatic one that is sent every second)? They're usually laid out in series next to each other and empty ones are 7FFF, so they shouldn't be hard to spot. If you want to work on this, consider it assigned to you.

[dankamongmen]

sure, i'll get on this over the weekend

[aleksamagicka]

(General info on writing these)

Virtual sensor values are sent through a USB bulk report, like this:

0000   04 7f ff 0e ea 13 88 7f ff 7f ff 7f ff 7f ff 7f
0010   ff 7f ff 7f ff 7f ff 7f ff 13 88 7f ff 7f ff 00
0020   3c 00 03 03 00 00 00 00 00 00 00 00 00 03 00 00
0030   07 64 64 64 64 64 64 64 64 64 64 64 64 64 64 64
0040   64 f5 68

The report ID is 0x04, and (at least for the Quadro) 16 virtual (software) sensors start at 0x01. As usual, each one is 2 bytes long. Here, the sixteenth one would have a value of 0x003c (60C).