Re: [RESUBMIT RFC PATCH v2 3/3] drivers: mfd: Add support for Exynos PMU driver

[Lee Jones <lee.jones@linaro.org>]

> >>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@samsung.com>
> >>CC: Samuel Ortiz <sameo@linux.intel.com>
> >>CC: Lee Jones <lee.jones@linaro.org>
> >>Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> >>---
> >>  arch/arm/mach-exynos/Kconfig                           |    2 ++
> >>  arch/arm/mach-exynos/Makefile                          |    2 --
> >>  drivers/mfd/Kconfig                                    |    9 +++++++++
> >>  drivers/mfd/Makefile                                   |    1 +
> >>  arch/arm/mach-exynos/pmu.c => drivers/mfd/exynos-pmu.c |    0
> >>  5 files changed, 12 insertions(+), 2 deletions(-)
> >>  rename arch/arm/mach-exynos/pmu.c => drivers/mfd/exynos-pmu.c (100%)
> >So I just took a look at the code as zero changes looks suspicious to
> >me. The driver can not simply be copied and pasted into the MFD
> >subsystem in its current state.
> >
> >The fundamental question is; is this chip actually an MFD? What does
> >it do besides Power Management?
> 
> Exynos PMU chip controls different power states of Exynos, so mainly it
> does power management related stuff. Apart from this it has few registers
> which controls PHY of various IP blocks of Exynos such as USB, HDMI,
> ADC etc. But these phy controlling register are currently being accessed
> via "syscon" driver provided regmap APIs. For same the same reason
> Exynos PMU has second compatibility string as "syscon".

I suggest that this is not suitable for the MFD subsystem then.

Try drivers/power.


-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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