This patch-set includes the two features as following. The generic
exynos bus frequency driver is able to support almost Exynos SoCs
for bus frequency scaling. And the new passive governor is able to
make the dependency on between devices for frequency/voltage
scaling. I had posted the patch-set[2] with the similiar concept.
This is is revised version for exynos bus frequency. - Generic
exynos bus frequency driver - New passive governor of DEVFREQ
framework

Depend on: - next-20151210 tag of linux-next (master branch). -
Merge the latest devfreq patches on devfreq.git[2] (for-rafael
branch). [1]
https://git.kernel.org/cgit/linux/kernel/git/mzx/devfreq.git/
(branch: for-rafael) [2] https://lkml.org/lkml/2015/1/7/872 :
[PATCHv3 0/8] devfreq: Add generic exynos memory-bus frequency
driver

Changes from v3: (https://lkml.org/lkml/2015/12/11/75) - Add the
reviewed-by tag from Krzysztof Kozlowski (patch2/3/13/14/15/16/17) 
- Fix typo of the description on patch14 - Modify the subject and
description of patch17 - Reorder the 'bus_xxx' device tree node
alphabetically in both exynos3250-rinato/monk.dts and
exynos4412-trats/odroidu3

Changes from v2: (https://lkml.org/lkml/2015/12/8/869) - Fix typo
on documentation - Modify the more appropriate sentence on patch
description - Add the detailed description about both parent and
passive bus device - Modify the DMC frequency for Exynos4x12 DMC
bus (200MHz -> 267MHz) - Modify the voltage of 200MHz was included
in Exynos3250 DMC bus (800mV -> 825mV) - Rename OPP nodes as
'opp@<opp-hz>' - Delete the duplicate 'opp-microvolt' property of
passive devfreq device - Reorder the 'bus_xxx' device tree node
alphabetically in exynos3250-rinato/monk.dts - Reorder the
'bus_xxx' device tree node alphabetically in
exynos4412-trats/odroidu3 - Add new exynos4412-ppmu-common.dtsi to
remove the duplicate PPMU dt node on rinato/monk/trats2/odroid-u3
board - Add the log message if bus device is registered to devfreq
framework successfully - Add the reviewed-by tag from Krzysztof
Kozlowski - Add the tested-by tag from Anand Moon on Odroid U3 -
Add 'SAMSUNG BUS FREQUENCY DRIVER' entry to MAINTAINERS

Changes from v1: (https://lkml.org/lkml/2015/11/26/260) - Check
whether the instance of regulator is NULL or not when executing
regulator_disable() because of only parent devfreq device has the
regulator instance. After fixing it, the wake-up from suspend state
is well working. (patch1) - Fix bug which checks 'bus-clk' instead
of 'bus->regulator' after calling devm_clk_get() (on patch1) -
Update the documentation to remove the description about 
DEVFREQ-EVENT subsystem (on patch2) - Add the full name of DMC
(Dynamic Memory Controller) (on patch2) - Modify the detailed
correlation of buses for Exynos3250 on documentation (patch2) - Add
the MFC bus node for Exynos3250 (on patch11, patch12) - Fix the
duplicate frequency of bus_display on Exynos4x12.dtsi - Add the
PPMU node for exynos4412-odroidu3 - Add the support of bus
frequency for exynos4412-odroidu3

Detailed descirption for patch-set: 1. Add generic exynos bus
frequency driver : This patch-set adds the generic exynos bus
frequency driver for AXI bus of sub-blocks in exynos SoC. The
Samsung Exynos SoC have the common architecture for bus between
DRAM and sub-blocks in SoC.

There are the different buses according to Exynos SoC because
Exynos SoC has the differnt sub-blocks and bus speed. In spite of
this difference among Exynos SoCs, this driver is able to support
almost Exynos SoC by adding unique data of each bus in the
devicetree file.

In devicetree, each bus node has a bus clock, regulator,
operation-point and devfreq-event devices which measure the
utilization of each bus block.

For example, - The bus of DMC block in exynos3250.dtsi are listed
below:

bus_dmc: bus_dmc { compatible = "samsung,exynos-bus"; clocks =
<&cmu_dmc CLK_DIV_DMC>; clock-names = "bus"; operating-points-v2 =
<&bus_dmc_opp_table>; status = "disabled"; };

bus_dmc_opp_table: opp_table1 { compatible =
"operating-points-v2"; opp-shared;

opp@50000000 { opp-hz = /bits/ 64 <50000000>; opp-microvolt =
<800000>; }; opp@100000000 { opp-hz = /bits/ 64 <100000000>; 
opp-microvolt = <800000>; }; opp@134000000 { opp-hz = /bits/ 64
<134000000>; opp-microvolt = <800000>; }; opp@200000000 { opp-hz =
/bits/ 64 <200000000>; opp-microvolt = <825000>; }; opp@400000000
{ opp-hz = /bits/ 64 <400000000>; opp-microvolt = <875000>; }; };

- Usage case to handle the frequency and voltage of bus on runtime 
in exynos3250-rinato.dts are listed below:

&bus_dmc { devfreq-events = <&ppmu_dmc0_3>, <&ppmu_dmc1_3>; 
vdd-supply = <&buck1_reg>;	/* VDD_MIF */ status = "okay"; };

2. Add new passive governor of DEVFREQ framework (patch5-patch7) :
This patch-set add the new passive governor for DEVFREQ framework. 
The existing governors (ondemand, performance and so on) are used
for DVFS (Dynamic Voltage and Frequency Scaling) drivers. The
existing governors are independently used for specific device
driver which don't give the influence to other device drviers and
also don't receive the effect from other device drivers.

The passive governor depends on operation of parent driver with
existing governors(ondemand, performance and so on) extremely and
is not able to decide the new frequency by oneself. According to
the decided new frequency of parent driver with governor, the
passive governor uses it to decide the appropriate frequency for
own device driver. The passive governor must need the following
information from device tree:

For exameple, There are one more bus device drivers in Exynos3250
which need to change their source clock according to their
utilization on runtime. But, they share the same power line (e.g.,
regulator). So, LEFTBUS bus driver is operated as parent with
ondemand governor and then the rest device driver with passive
governor.

The buses of Internal block in exynos3250.dtsi are listed below: 
When LEFTBUS bus driver (parent) changes the bus frequency with 
ondemand governor on runtime, the rest bus devices which sharing 
the same power line (VDD_INT) will change the each bus frequency 
according to the decision of LEFTBUS bus driver (parent).

- INT (Internal) block : VDD_INT |--- LEFTBUS |--- PERIL |--- MFC 
|--- G3D |--- RIGHTBUS |--- FSYS |--- LCD0 |--- PERIR |--- ISP |---
CAM

- The buss of INT block in exynos3250.dtsi are listed below: 
bus_leftbus: bus_leftbus { compatible = "samsung,exynos-bus"; 
clocks = <&cmu CLK_DIV_GDL>; clock-names = "bus"; 
operating-points-v2 = <&bus_leftbus_opp_table>; status =
"disabled"; };

bus_rightbus: bus_rightbus { compatible = "samsung,exynos-bus"; 
clocks = <&cmu CLK_DIV_GDR>; clock-names = "bus"; 
operating-points-v2 = <&bus_leftbus_opp_table>; status =
"disabled"; };

(Omit the rest bus dt node)

- Usage case to handle the frequency and voltage of bus on runtime 
in exynos3250-rinato.dts are listed below: /* Parent bus device of
VDD_INT */ &bus_leftbus { devfreq-events = <&ppmu_leftbus_3>,
<&ppmu_rightbus_3>; vdd-supply = <&buck3_reg>; status = "okay"; };

/* Passive bus device depend on LEFTBUS bus. */ &bus_rightbus { 
devfreq = <&bus_leftbus>; /* 'devfreq' property indicates the
phandle of parent device. */ status = "okay"; };

(Omit the rest bus dt node)

Chanwoo Choi (20): PM / devfreq: exynos: Add generic exynos bus
frequency driver PM / devfreq: exynos: Add documentation for
generic exynos bus frequency driver ARM: dts: Add DMC bus node for
Exynos3250 ARM: dts: Add DMC bus frequency for
exynos3250-rinato/monk PM / devfreq: Add new passive governor PM /
devfreq: Add devfreq_get_devfreq_by_phandle() PM / devfreq: Show
the related information according to governor type PM / devfreq:
exynos: Add support of bus frequency of sub-blocks using passive
governor PM / devfreq: exynos: Update documentation for bus devices
using passive governor PM / devfreq: exynos: Add the detailed
correlation between sub-blocks and power line PM / devfreq: exynos:
Remove unused exynos4/5 busfreq driver MAINTAINERS: Add samsung bus
frequency driver entry ARM: dts: Add bus nodes using VDD_INT for
Exynos3250 ARM: dts: Add bus nodes using VDD_MIF for Exynos4x12 
ARM: dts: Add bus nodes using VDD_INT for Exynos4x12 ARM: dts: Add
bus nodes using VDD_MIF for Exynos4210 ARM: dts: Add
exynos4412-ppmu-common dtsi to delete duplicate PPMU nodes ARM:
dts: Add support of bus frequency using VDD_INT for
exynos3250-rinato ARM: dts: Expand the voltage range of buck1/3
regulator for exynos4412-odroidu3 ARM: dts: Add support of bus
frequency for exynos4412-trats/odroidu3

.../devicetree/bindings/devfreq/exynos-bus.txt     |  388 +++++++ 
MAINTAINERS                                        |    9 + 
arch/arm/boot/dts/exynos3250-monk.dts              |   47 +- 
arch/arm/boot/dts/exynos3250-rinato.dts            |   88 +- 
arch/arm/boot/dts/exynos3250.dtsi                  |  181 ++++ 
arch/arm/boot/dts/exynos4210.dtsi                  |  159 +++ 
arch/arm/boot/dts/exynos4412-odroid-common.dtsi    |   54 +- 
arch/arm/boot/dts/exynos4412-ppmu-common.dtsi      |   50 + 
arch/arm/boot/dts/exynos4412-trats2.dts            |   88 +- 
arch/arm/boot/dts/exynos4x12.dtsi                  |  174 ++++ 
drivers/devfreq/Kconfig                            |   37 +- 
drivers/devfreq/Makefile                           |    2 + 
drivers/devfreq/devfreq.c                          |  120 ++- 
drivers/devfreq/exynos/Makefile                    |    3 +- 
drivers/devfreq/exynos/exynos-bus.c                |  556
+++++++++++ drivers/devfreq/exynos/exynos4_bus.c               |
1055 -------------------- drivers/devfreq/exynos/exynos4_bus.h
|  110 -- drivers/devfreq/exynos/exynos5_bus.c               |  431
-------- drivers/devfreq/exynos/exynos_ppmu.c               |  119

--- drivers/devfreq/exynos/exynos_ppmu.h               |   86 -- 

drivers/devfreq/governor.h                         |    7 + 
drivers/devfreq/governor_passive.c                 |  109 ++ 
drivers/devfreq/governor_performance.c             |    1 + 
drivers/devfreq/governor_powersave.c               |    1 + 
drivers/devfreq/governor_simpleondemand.c          |    1 + 
drivers/devfreq/governor_userspace.c               |    1 + 
include/linux/devfreq.h                            |   26 + 27
files changed, 1955 insertions(+), 1948 deletions(-) create mode
100644 Documentation/devicetree/bindings/devfreq/exynos-bus.txt 
create mode 100644 arch/arm/boot/dts/exynos4412-ppmu-common.dtsi 
create mode 100644 drivers/devfreq/exynos/exynos-bus.c delete mode
100644 drivers/devfreq/exynos/exynos4_bus.c delete mode 100644
drivers/devfreq/exynos/exynos4_bus.h delete mode 100644
drivers/devfreq/exynos/exynos5_bus.c delete mode 100644
drivers/devfreq/exynos/exynos_ppmu.c delete mode 100644
drivers/devfreq/exynos/exynos_ppmu.h create mode 100644
drivers/devfreq/governor_passive.c