diff mbox

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

Message ID 1414986790-11940-3-git-send-email-amit.daniel@samsung.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Amit Kachhap Nov. 3, 2014, 3:53 a.m. UTC
From: Pankaj Dubey <pankaj.dubey@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@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>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@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%)

diff --git a/arch/arm/mach-exynos/pmu.c b/drivers/mfd/exynos-pmu.c
similarity index 100%
rename from arch/arm/mach-exynos/pmu.c
rename to drivers/mfd/exynos-pmu.c

Comments

Lee Jones Nov. 3, 2014, 3:26 p.m. UTC | #1
On Mon, 03 Nov 2014, Amit Daniel Kachhap wrote:

> From: Pankaj Dubey <pankaj.dubey@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@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>
> Signed-off-by: Amit Daniel Kachhap <amit.daniel@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
Pankaj Dubey Nov. 4, 2014, 3:18 a.m. UTC | #2
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@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@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>
> > Signed-off-by: Amit Daniel Kachhap <amit.daniel@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
> for ARM SoCs Follow Linaro: Facebook | Twitter | Blog

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Lee Jones Nov. 4, 2014, 8:24 a.m. UTC | #3
On Tue, 04 Nov 2014, Pankaj Dubey wrote:
> 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@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@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>
> > > Signed-off-by: Amit Daniel Kachhap <amit.daniel@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.

There are no valid points for keeping PMU code in MFD.

> 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.

MFD can be used to register the device, but the driver must not live
in MFD.  Please relocate it into drivers/power.
On 04/11/14 04:18, Pankaj Dubey wrote:
> 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.

We have DT binding for the Exynos power domains:
Documentation/devicetree/bindings/arm/exynos/power_domain.txt
In fact the IO memory regions used in the power domain bindings
fall within the (sparse) PMU registers region.

There is also DT binding for the PMU subsystem:
Documentation/devicetree/bindings/arm/samsung/pmu.txt

I guess a platform device driver in drivers/power would be a better
fit than drivers/mfd. I doubt introducing an mfd driver now makes
much sense, we have already DT bindings for PHYs, the power domains,
etc.

--
Thanks,
Sylwester
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diff mbox

Patch

diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index 96d56ab..c2aef3f 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -25,6 +25,7 @@  menuconfig ARCH_EXYNOS
 	select S5P_DEV_MFC
 	select SRAM
 	select MFD_SYSCON
+	select MFD_EXYNOS_PMU
 	help
 	  Support for SAMSUNG EXYNOS SoCs (EXYNOS4/5)
 
diff --git a/arch/arm/mach-exynos/Makefile b/arch/arm/mach-exynos/Makefile
index bcefb54..b91b382 100644
--- a/arch/arm/mach-exynos/Makefile
+++ b/arch/arm/mach-exynos/Makefile
@@ -9,7 +9,7 @@  ccflags-$(CONFIG_ARCH_MULTIPLATFORM) += -I$(srctree)/$(src)/include -I$(srctree)
 
 # Core
 
-obj-$(CONFIG_ARCH_EXYNOS)	+= exynos.o pmu.o exynos-smc.o firmware.o
+obj-$(CONFIG_ARCH_EXYNOS)	+= exynos.o exynos-smc.o firmware.o
 
 obj-$(CONFIG_EXYNOS_CPU_SUSPEND) += pm.o sleep.o
 obj-$(CONFIG_PM_SLEEP)		+= suspend.o
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index cbdb109..619a9ba 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1323,6 +1323,15 @@  config MFD_STW481X
 	  in various ST Microelectronics and ST-Ericsson embedded
 	  Nomadik series.
 
+config MFD_EXYNOS_PMU
+	tristate "Support Exynos Power Management Unit"
+	depends on ARM || ARM64
+	help
+	  Exynos SoC have Power Management Unit (PMU) which controls power and
+	  operation state of Exynos SoC in two different ways. This driver
+	  provides implementation of PMU driver and provides basic functionality
+	  required during these operation state.
+
 menu "Multimedia Capabilities Port drivers"
 	depends on ARCH_SA1100
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 8e679d6..33489b4 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -175,6 +175,7 @@  obj-$(CONFIG_MFD_STW481X)	+= stw481x.o
 obj-$(CONFIG_MFD_IPAQ_MICRO)	+= ipaq-micro.o
 obj-$(CONFIG_MFD_MENF21BMC)	+= menf21bmc.o
 obj-$(CONFIG_MFD_HI6421_PMIC)	+= hi6421-pmic-core.o
+obj-$(CONFIG_MFD_EXYNOS_PMU)	+= exynos-pmu.o
 
 intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o