Charge counter on droid 4

[tony@atomide.com (Tony Lindgren)]

* Pavel Machek <pavel@ucw.cz> [180615 08:34]:
> On Fri 2018-06-15 10:00:14, Pavel Machek wrote:
> > Hi!
> > 
> > Droid 4 has non-removable battery, yet the charge counter is reset to
> > near zero on each boot of linux.

Not sure if we actively do anything to reset it. I'm guessing
it's the Motorola bootloader that resets everything on boot.

> > Unfortunately, that makes charge counter pretty much useless on d4, as
> > the "battery full" and "battery empty" limits will be different during
> > each boot.

>From what I've seen also the stock kernel starts only with
voltage based estimate initially after a reboot?

> Hmm, and could we refrain from providing "power" values?
> 
> I was thinking great, we have hardware that does proper power
> measuerement for us. No.... it is driver providing synthetic
> values. As userland has enough information to do that itself, I
> believe we should not do this in kernel.

Hmm I don't follow you, why would we want to remove these as
they implement a standard sysfs interface?

I use the sysfs interface all the time to monitor the power
consumption and the output seems to match what I was seeing
with my power supply.

Note that we also have the IIO raw data also available if that
might help.

Regards,

Tony