Re: [PATCH v9 2/6] mfd: mp2629: Add support for mps battery charger

[saravanan sekar]

Hi Lee,

On 27/04/20 10:51 am, Lee Jones wrote:
> On Fri, 24 Apr 2020, saravanan sekar wrote:
>
> > On 24/04/20 12:53 pm, Lee Jones wrote:
> > > On Fri, 24 Apr 2020, saravanan sekar wrote:
> > >
> > > > Hi Lee,
> > > >
> > > > On 24/04/20 11:37 am, Lee Jones wrote:
> > > > > On Fri, 24 Apr 2020, saravanan sekar wrote:
> > > > >
> > > > > > Hi Lee,
> > > > > >
> > > > > > On 24/04/20 9:18 am, Lee Jones wrote:
> > > > > > > On Wed, 15 Apr 2020, Saravanan Sekar wrote:
> > > > > > >
> > > > > > > > mp2629 is a highly-integrated switching-mode battery charge management
> > > > > > > > device for single-cell Li-ion or Li-polymer battery.
> > > > > > > >
> > > > > > > > Add MFD core enables chip access for ADC driver for battery readings,
> > > > > > > > and a power supply battery-charger driver
> > > > > > > >
> > > > > > > > Signed-off-by: Saravanan Sekar <sravanhome@xxxxxxxxx>
> > > > > > > > ---
> > > > > > > >      drivers/mfd/Kconfig        |  9 ++++
> > > > > > > >      drivers/mfd/Makefile       |  2 +
> > > > > > > >      drivers/mfd/mp2629.c       | 86 ++++++++++++++++++++++++++++++++++++++
> > > > > > > >      include/linux/mfd/mp2629.h | 19 +++++++++
> > > > > > > >      4 files changed, 116 insertions(+)
> > > > > > > >      create mode 100644 drivers/mfd/mp2629.c
> > > > > > > >      create mode 100644 include/linux/mfd/mp2629.h
> > > > > > > How is this driver registered?
> > > > > > >
> > > > > > > Looks like it has device tree support.  Is there another way?
> > > > > > Yes, only using device tree
> > > > > Then how about using 'simple-mfd' and 'syscon'?
> > > > >
> > > > > Then you can omit this driver completely.
> > > > The exception is to support for non device tree platform as well, but I have
> > > > tested only for ARM device tree platform.
> > > Is that a reality though?
> > >
> > > How else do you see this realistically being registered?
> > I understand that acpi related device table are not covered here, well I
> > don't have to platform to test so.
> > If you ask me to cover acpi related table, I can do but hard to test.
> I don't know of any reasons why syscon can't be used by ACPI.
>
> Please try to solve this issue using 'simple-mfd' and 'syscon'.
Well the simple-mfd and syscon topic recommended by you when Device tree 
alone is used.
I wounder still I receive review/improvements comments for this mfd 
patch and also another
to omit this driver using simple-mfd (rework the series).
Confused, not sure which is valid and will be accepted at the end.
> > > > > > > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > > > > > > > index 3c547ed575e6..85be799795aa 100644
> > > > > > > > --- a/drivers/mfd/Kconfig
> > > > > > > > +++ b/drivers/mfd/Kconfig
> > > > > > > > @@ -434,6 +434,15 @@ config MFD_MC13XXX_I2C
> > > > > > > >      	help
> > > > > > > >      	  Select this if your MC13xxx is connected via an I2C bus.
> > > > > > > > +config MFD_MP2629
> > > > > > > > +	tristate "Monolithic power system MP2629 ADC and Battery charger"
> > > > > > > > +	depends on I2C
> > > > > > > > +	select REGMAP_I2C
> > > > > > > > +	help
> > > > > > > > +	  Select this option to enable support for monolithic power system
> > > > > > > > +	  battery charger. This provides ADC, thermal, battery charger power
> > > > > > > > +	  management functions on the systems.