[RFC v2 0/4] power: supply: Add Support for RK817 Charger

[Peter Geis]

On Wed, Jul 28, 2021 at 10:15 AM Chris Morgan <macromorgan at hotmail.com> wrote:
>
> On Wed, Jul 28, 2021 at 08:57:52AM -0400, Peter Geis wrote:
> > On Mon, Jul 26, 2021 at 3:02 PM Chris Morgan <macroalpha82 at gmail.com> wrote:
> > >
> > > From: Chris Morgan <macromorgan at hotmail.com>
> > >
> > > As this is my first charger driver, I'm submitting it as an RFC so I
> > > can get input from the community on what else is needed to make the
> > > driver consistent with the quality upstream expects.
> > >
> > > This series is to add support for the Rockchip rk817 battery charger
> > > which is present in all Rockchip RK817 PMICs. The driver was written
> > > as a joint effort by Maya Matuszczyk <maccraft123mc at gmail.com> and
> > > myself Chris Morgan <macromorgan at hotmail.com>.
> > >
> > > The driver requires some basic parameters be described about the
> > > battery in the devicetree such as the maximum capacity, the minimum
> > > and maximum voltage for the battery, the maximum charge current, the
> > > maximum charge voltage, and the value of sample resistors and sleep
> > > currents.
> > >
> > > The hardware itself contains an ADC capable of measuring the voltage,
> > > current, and temperature of the battery (though my implementation of an
> > > Odroid Go Advance lacks a thermistor for temperature). It also contains
> > > a columb counter, registers for tracking the measured voltage and
> > > current at boot, and a few bytes of nvram for storing data.
> >
> > Feel free to add my Tested-by: Peter Geis <pgwipeout at gmail.com>
>
> Thank you. Have you checked out the audio driver yet? Would be nice to
> see how it works on a device other than the Odroid Go Advance.

I would love to, but we still need to port the i2s-tdm driver over for
that functionality in the rk356x.
Once we have that, I'll be happy to test it.

>
> >
> > Tested on the Pine64 Quartz64 Model A.
> > We can't go as low on the battery voltage, otherwise the SOC becomes
> > unstable before it can shut down.
> > <3625000 0> seems sufficient for us though (adding this for the
> > benefit of anyone else testing).
> >
> > Voltages are accurate as measured at the battery.
> > Are there plans to expose the thermal sensor (if that's possible)?
>
> Unfortunately it might be more than we are capable of. The output of
> the thermal sensor from the ADC is stored in register 0x7c and 0x7d,
> however the datasheet doesn't tell me the scale/how to translate it
> to degrees. For the other ADC values there were coefficients in the
> BSP kernel, but there is nothing for the temperature unfortunately.
> Additionally, my hardware doesn't have a thermistor, so even if I
> wanted to reverse engineer it some way I don't have the means. For
> me those registers just read 0xff 0xff, which I assume is what it
> reads when the values are not present.

Okay, we have the thermistor connected so I can look into this.

>
> >
> > >
> > > Changes from V1:
> > >
> > >  - Fixed a CLANG warning regarding an uninitalized variable.
> > >  - Fixed a CLANG warning regarding a pointer as a bool value always
> > >    returning as true.
> > >  - Added Maya Matuszczyk to the Signed-off-by.
> > >
> > > Chris Morgan (4):
> > >   [RFC v2 1/4] dt-bindings: Add Rockchip rk817 battery charger support
> > >   [RFC v2 2/4] mfd: Add Rockchip rk817 battery charger support
> > >   [RFC v2 3/4] power: supply: Add charger driver for Rockchip RK817
> > >   [RFC 4/4] arm64: dts: rockchip: add rk817 charger to Odroid Go Advance
> > >
> > >  .../devicetree/bindings/mfd/rk808.txt         |  35 +-
> > >  .../boot/dts/rockchip/rk3326-odroid-go2.dts   |  25 +
> > >  drivers/mfd/rk808.c                           |  16 +-
> > >  drivers/power/supply/Kconfig                  |   6 +
> > >  drivers/power/supply/Makefile                 |   1 +
> > >  drivers/power/supply/rk817_charger.c          | 932 ++++++++++++++++++
> > >  include/linux/mfd/rk808.h                     |  87 ++
> > >  7 files changed, 1099 insertions(+), 3 deletions(-)
> > >  create mode 100644 drivers/power/supply/rk817_charger.c
> > >
> > > --
> > > 2.25.1
> > >
> > >
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