Re: [PATCH v2 00/19] PM / devferq: Add generic exynos bus frequency driver and new passive governor

From: Anand Moon <linux.amoon@gmail.com>
To: Chanwoo Choi <cw00.choi@samsung.com>
Cc: myungjoo.ham@samsung.com,
	"Krzysztof Kozłowski" <k.kozlowski@samsung.com>,
	"Kukjin Kim" <kgene@kernel.org>,
	"Kyungmin Park" <kyungmin.park@samsung.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Pawel Moll" <pawel.moll@arm.com>,
	"Mark Rutland" <mark.rutland@arm.com>,
	"Ian Campbell" <ijc+devicetree@hellion.org.uk>,
	"Kumar Gala" <galak@codeaurora.org>,
	"Russell King" <linux@arm.linux.org.uk>,
	"Tobias Jakobi" <tjakobi@math.uni-bielefeld.de>,
	"Linux Kernel" <linux-kernel@vger.kernel.org>,
	"Linux PM list" <linux-pm@vger.kernel.org>,
	"linux-samsung-soc@vger.kernel.org"
	<linux-samsung-soc@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>
Subject: Re: [PATCH v2 00/19] PM / devferq: Add generic exynos bus frequency driver and new passive governor
Date: Thu, 10 Dec 2015 00:35:57 +0530	[thread overview]
Message-ID: <CANAwSgS17rJW+ey3aFmR=uf54w9mjfW-drZr3=cQwvg7p0C9Lg@mail.gmail.com> (raw)
In-Reply-To: <1449634091-1842-1-git-send-email-cw00.choi@samsung.com>

Hi Chanwoo Choi,

On 9 December 2015 at 09:37, Chanwoo Choi <cw00.choi@samsung.com> wrote:
> 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[1]
> with the similiar concept. This is is revised version for exynos bus frequency.
> - Generic exynos bus frequency driver
> - New passive governor of DEVFREQ framework
>
> Depends on:
> - This patch-set is based on devfreq.git[2].
> [1] https://lkml.org/lkml/2015/1/7/872
>    : [PATCHv3 0/8] devfreq: Add generic exynos memory-bus frequency driver
> [2] https://git.kernel.org/cgit/linux/kernel/git/mzx/devfreq.git/ (branch: for-rafael)
>
> 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_table0 {
>                 compatible = "operating-points-v2";
>                 opp-shared;
>
>                 opp00 {
>                         opp-hz = /bits/ 64 <50000000>;
>                         opp-microvolt = <800000>;
>                 };
>                 opp01 {
>                         opp-hz = /bits/ 64 <100000000>;
>                         opp-microvolt = <800000>;
>                 };
>                 opp02 {
>                         opp-hz = /bits/ 64 <134000000>;
>                         opp-microvolt = <800000>;
>                 };
>                 opp03 {
>                         opp-hz = /bits/ 64 <200000000>;
>                         opp-microvolt = <800000>;
>                 };
>                 opp04 {
>                         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 (19):
>   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
>   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 PPMU node for exynos4412-odroidu3
>   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     |  383 +++++++
>  arch/arm/boot/dts/exynos3250-monk.dts              |    6 +
>  arch/arm/boot/dts/exynos3250-rinato.dts            |   47 +
>  arch/arm/boot/dts/exynos3250.dtsi                  |  194 ++++
>  arch/arm/boot/dts/exynos4210.dtsi                  |  172 ++++
>  arch/arm/boot/dts/exynos4412-odroid-common.dtsi    |   93 +-
>  arch/arm/boot/dts/exynos4412-trats2.dts            |   47 +
>  arch/arm/boot/dts/exynos4x12.dtsi                  |  184 ++++
>  drivers/devfreq/Kconfig                            |   37 +-
>  drivers/devfreq/Makefile                           |    2 +
>  drivers/devfreq/devfreq.c                          |  120 ++-
>  drivers/devfreq/exynos/Makefile                    |    3 +-
>  drivers/devfreq/exynos/exynos-bus.c                |  549 ++++++++++
>  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                            |   28 +
>  25 files changed, 1958 insertions(+), 1828 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/devfreq/exynos-bus.txt
>  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
>
> --
> 1.9.1
>

I could not get this series to work with my Odroid U3.

[    4.602768] input: gpio_keys as /devices/platform/gpio_keys/input/input0
[    4.605527] devfreq bus_leftbus: Couldn't update frequency
transition information.
[    4.607319] devfreq bus_dmc: Couldn't update frequency transition
information.
[    4.625096] usb 1-3: New USB device found, idVendor=0424, idProduct=3503

-Anand Moon