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

Anand Moon
2015-12-10T04:14:49Z

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.

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>

-Anand Moon