[POWER] battery calibration parameters from sysfs

[Stanislav Brabec]

Aras Vaichas wrote:

> Yes, but in that case you might as well just purchase a coulomb
> counter with a built-in accumulator and an I2C/SPI/microwire interface
> save yourself some PCB space and cost (maybe)

Well, Pavel attempts to implement a "poor man's Coulomb counter" or at
least "poor man's Ampere meter" for devices that are not equipped with
any of it.

- We know the time.
- We know the backlight power consumption, it's dependent only on
  brightness.
- We know how much eats the HDD and how long it is on.
- We know how much eats the CPU and companion chips (it is not as
  stable, but it eats less).
- We don't know, how much USB host eats, but we know how much USB
  clients claim to eat.
- Well, and we don't know how much eats CF and SD.

=> We can guess how many Coulombs the device already consumed. If the
Coulomb counting would be inaccurate, we can at least correct voltage ->
remaining energy table using current power consumption guess.


________________________________________________________________________
Stanislav Brabec
http://www.penguin.cz/~utx/zaurus