Charge counter on droid 4

* Pavel Machek [off-list ref] [180615 08:34]:

On Fri 2018-06-15 10:00:14, Pavel Machek wrote:

quoted

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.

quoted

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