[PATCH 02/12] drivers: mfd: Add support for Exynos PMU driver

[Pankaj Dubey]

Hi Lee,

On Monday, November 03, 2014 8:56 PM, Lee Jones wrote,
> Subject: Re: [PATCH 02/12] drivers: mfd: Add support for Exynos PMU driver
> 
> On Mon, 03 Nov 2014, Amit Daniel Kachhap wrote:
> 
> > From: Pankaj Dubey <pankaj.dubey at samsung.com>
> >
> > This patch moves Exynos PMU driver implementation from "arm/mach-exynos"
> > to "drivers/mfd". This driver is mainly used for setting misc bits of
> > register from PMU IP of Exynos SoC which will be required to configure
> > before Suspend/Resume. Currently all these settings are done in
> > "arch/arm/mach-exynos/pmu.c" but moving ahead for ARM64 based SoC
> > support, there is a need of DT based implementation of PMU driver.
> >
> > This driver uses already existing DT binding information.
> >
> > CC: Sangbeom Kim <sbkim73 at samsung.com>
> > CC: Samuel Ortiz <sameo at linux.intel.com>
> > CC: Lee Jones <lee.jones at linaro.org>
> > Signed-off-by: Pankaj Dubey <pankaj.dubey at samsung.com>
> > Signed-off-by: Amit Daniel Kachhap <amit.daniel at samsung.com>
> > ---
> >  arch/arm/mach-exynos/Kconfig                       |    1 +
> >  arch/arm/mach-exynos/Makefile                      |    2 +-
> >  drivers/mfd/Kconfig                                |    9 +++++++++
> >  drivers/mfd/Makefile                               |    1 +
> >  .../mach-exynos/pmu.c => drivers/mfd/exynos-pmu.c  |    0
> >  5 files changed, 12 insertions(+), 1 deletion(-)  rename
> > arch/arm/mach-exynos/pmu.c => drivers/mfd/exynos-pmu.c (100%)
> 
> I thought we spoke about this already [1]?  What's changed?
> 
> [1] https://lkml.org/lkml/2014/4/29/193
> 

Yes correct, we had discussion about this in above post. But at that time I was not having enough points to
put forward for keeping Exynos PMU driver in MFD folder.
At that point there was only one idea behind keeping Exynos PMU that in future it will be reused for ARM64
based SoC for PM related functionalities.
But in this series we have implemented Exynos Power Domain for Samsung's ARM64 based SoCs.

As far as I can see this will in following ways -

1: Moving out PM domain specific code from mach-exynos and reuse of same code for ARM64 based SoC also.
2: Since PM domain relies on PMU registers and does not have its own DT binding, MFD client and MFD device
is most suitable for making this kind of platform drivers.

> --
> Lee Jones
> Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software
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