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

[Chanwoo Choi <cw00.choi@samsung.com>]

Hi Anand,

On 2015년 12월 10일 13:14, Anand Moon wrote:
> Hi Chanwoo Choi,
> 
> On 10 December 2015 at 05:42, Chanwoo Choi <cw00.choi@samsung.com> wrote:
>> Hi Anand,
>>
>> First of all, thanks for trying to test this series.
>>
>> On 2015년 12월 10일 04:05, Anand Moon wrote:
>>> 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
>>
>> This log indicates the problem of 'trats_stat' sysfs entry of devfreq framework
>> during kernel booting. But, this log don't affect the behavior of bus frequency
>> on Odroid-U3.
>>
>> After completing kernel and platform booting, you can check the operation
>> of Bus frequency with follwoing sysfs entry:
>>
>> root@localhost:~# ls -al /sys/class/devfreq
>> total 0
>> drwxr-xr-x  2 root root 0 Dec 31 17:00 .
>> drwxr-xr-x 44 root root 0 Dec 31 17:00 ..
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_acp -> ../../devices/platform/bus_acp/devfreq/bus_acp
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_c2c -> ../../devices/platform/bus_c2c/devfreq/bus_c2c
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_display -> ../../devices/platform/bus_display/devfreq/bus_display
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_dmc -> ../../devices/platform/bus_dmc/devfreq/bus_dmc
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_fsys -> ../../devices/platform/bus_fsys/devfreq/bus_fsys
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_leftbus -> ../../devices/platform/bus_leftbus/devfreq/bus_leftbus
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_mfc -> ../../devices/platform/bus_mfc/devfreq/bus_mfc
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_peri -> ../../devices/platform/bus_peri/devfreq/bus_peri
>> lrwxrwxrwx  1 root root 0 Dec 31 17:00 bus_rightbus -> ../../devices/platform/bus_rightbus/devfreq/bus_rightbus
>>
>> root@localhost:~# cat /sys/class/devfreq/bus_leftbus/trans_stat
>>      From  :   To
>>            : 100000000 134000000 160000000 200000000   time(ms)
>>   100000000:         0         0         0        24      2020
>>   134000000:         0         0         0        10      1190
>>   160000000:         0         0         0         0         0
>> * 200000000:        24        10         0         0    118160
>> Total transition : 68
>>
>> Also, when changing the frequency of each bus, exynos-bus.c show
>> the debug message. If you need more detailed information,
>> you could check this log message.
>>
>> Regards,
>> Chanwoo Choi
> 
> Thanks for you input. It seem to be working I have see the counter increment.
> Sorry for the noise.

No problem.

> 
> root@odroidu3:~# cat /sys/class/devfreq/bus_dmc/trans_stat
>      From  :   To
>            : 100000000 134000000 160000000 200000000 400000000   time(ms)
>   100000000:         0         0         0         0         2       560
>   134000000:         0         0         0         0         1       190
>   160000000:         0         0         0         0         0         0
>   200000000:         0         0         0         0         2       310
> * 400000000:         2         1         0         2         0    332400
> Total transition : 10
> root@odroidu3:~# cat /sys/class/devfreq/bus_rightbus/trans_stat
> Not Supported.
> root@odroidu3:~#
> 
> Tested on Odroid U3
> Tested-by: Anand Moon <linux.amoon@gmail.com>

Thanks for your test.

Best Regards,
Chanwoo Choi