Re: [PATCH V12 00/14] Krait clocks + Krait CPUfreq

From: Sricharan R
Date: Fri Sep 07 2018 - 05:57:52 EST


Hi Craig,


>> [v12]
>> * Added my signed-off that was missing in some patches.
>> * Added Bjorn's acked that i missed earlier.
>>
>
> Can you give this a try on your 8974 device and check if the
> pvs version reporting, scaling for higher frequencies are fine ?
> Sorry, i could not get hold of a 8974 device. So in-case if you still
> have the issues with higher frequencies, can you give a quick debug
> and report. That would be of great help.
>
Ping on this ..

Regards,
Sricharan

> Regards,
> Sricharan
>
>
>> [v11]
>> * Dropped patch 13 and 14 from v10 and
>> merged the qcom-cpufreq-krait driver to the existing qcom-cpufreq-kryo.c
>> * Rebased on top of clk-next
>> * Fixed a bug while populating the pvs version for krait.
>>
>> [v10]
>> * Addressed Stephen's comments to add clocks bindings properties
>> to the newly introduced nodes.
>> * Added a change to include opp-supported-hw to qcom-cpufreq.c
>> * Rebased on top of clk-next
>> * Although there were minor changes to bindings and the driver
>> retained the acked-by tags from Rob and Viresh respectively.
>>
>> [v9]
>> * Fixed a rebase issue in Makefile and added Tag from Robh.
>>
>> [v8]
>> * Fixed a bug in path#14 pointed out by Viresh and also added tags.
>> No change in any other patch.
>>
>> [v7]
>> * Fixed comments from Viresh for cleaning up the error handling
>> in qcom-cpufreq.c. Also changed the init function to lateinit
>> call. This is required because nvmem which gets initialised with
>> module_init needs to go first.
>> * Fixed Rob's comments for bindings documentation
>> * Fixed kbuild build issue in clk-lpc32xx.c
>> * Rebased on top of clk-next
>>
>> [v6]
>> * Adrressed comments from Viresh for patch #14 in v5 [5]
>> * Introduced a new binding operating-points-v2-krait-cpu
>> as per discussion with Rob
>> * Added Review tags
>>
>> [v5]
>> * Addressed comments from Rob for bindings
>> * Addressed comments from Viresh to use dev_pm_opp_set_prop_name, accordingly
>> dropped patch #12 and corrected patch #11 from previous patch set in [4]
>> * Converted to use #spdx tags for newly introduced files
>>
>> Mostly a resend of the v3 posted by Stephen quite some time back [1]
>> except for few changes.
>> Based on reading some feedback from list,
>> * Dropped the patch "clk: Add safe switch hook" from v3 [2].
>> Now this is taken care by patch#10 in this series only for Krait.
>> * Dropped the path "clk: Avoid sending high rates to downstream
>> clocks during set_rate" from v3 [3].
>> * Rebased on top of clk-next.
>> * Dropped the DT update from the series. Will send separately
>> * Now with cpufreq-dt+opp supporting voltage scaling, registering the
>> krait cpu supplies in DT should be sufficient. But one issue is,
>> the qcom-cpufreq drivers reads the efuse and based on that registers
>> the opp data and then registers the cpufreq-dt device. So when
>> cpufreq-dt driver probes and registers the regulator to the OPP framework,
>> it expects that the opp data for the device should not be registered before
>> the regulator. Will send a RFC patch removing that check, to find out the
>> right way of doing it.
>>
>> These patches provide cpufreq scaling on devices with Krait CPUs.
>> In Krait CPU designs there's one PLL and two muxes per CPU, allowing
>> us to switch CPU frequencies independently.
>>
>> secondary
>> +-----+ +
>> | QSB |-------+------------|\
>> +-----+ | | |-+
>> | +-------|/ |
>> | | + |
>> +-----+ | | |
>> | PLL |----+-------+ | primary
>> +-----+ | | | +
>> | | +-----|\ +------+
>> +-------+ | | | \ | |
>> | HFPLL |----------+-----------------| |-----| CPU0 |
>> +-------+ | | | | | | |
>> | | | +-----+ | / +------+
>> | | +-| / 2 |---------|/
>> | | +-----+ +
>> | | secondary
>> | | +
>> | +------------|\
>> | | |-+
>> +---------------|/ | primary
>> + | +
>> +-----|\ +------+
>> +-------+ | \ | |
>> | HFPLL |----------------------------| |-----| CPU1 |
>> +-------+ | | | | |
>> | +-----+ | / +------+
>> +-| / 2 |---------|/
>> +-----+ +
>>
>> To support this in the common clock framework we model the muxes,
>> dividers, and PLLs as different clocks. CPUfreq only interacts
>> with the primary mux (farthest right in the diagram). When CPUfreq
>> sets a rate, the mux code finds the best parent that can provide the rate.
>> Due to the design, QSB and the top PLL are always a fixed rate and thus
>> only support one frequency each. These sources provide the lowest
>> frequencies for the CPUs. The HFPLLs are where we can make the CPU go
>> faster (GHz range). Sometimes we need to run the HFPLL twice as
>> fast and divide it by two to get a particular frequency.
>>
>> When switching rates we can't leave the CPU clocked by the HFPLL because
>> we need to turn off the output of the PLL when changing its frequency.
>> This means we have to switch over to the secondary mux and use one of the
>> fixed sources. This is why we need something like the safe parent patch.
>>
>> [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/332607.html
>> [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/332615.html
>> [3] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/332608.html
>> [4] https://lwn.net/Articles/740994/
>> [5] https://lkml.org/lkml/2017/12/19/537
>>
>>
>> Sricharan R (3):
>> clk: qcom: Add safe switch hook for krait mux clocks
>> cpufreq: qcom: Re-organise kryo cpufreq to use it for other nvmem
>> based qcom socs
>> cpufreq: qcom: Add support for krait based socs
>>
>> Stephen Boyd (11):
>> ARM: Add Krait L2 register accessor functions
>> clk: qcom: Add support for High-Frequency PLLs (HFPLLs)
>> clk: qcom: Add HFPLL driver
>> dt-bindings: clock: Document qcom,hfpll
>> clk: qcom: Add MSM8960/APQ8064's HFPLLs
>> clk: qcom: Add IPQ806X's HFPLLs
>> clk: qcom: Add support for Krait clocks
>> clk: qcom: Add KPSS ACC/GCC driver
>> dt-bindings: arm: Document qcom,kpss-gcc
>> clk: qcom: Add Krait clock controller driver
>> dt-bindings: clock: Document qcom,krait-cc
>>
>> .../devicetree/bindings/arm/msm/qcom,kpss-acc.txt | 19 +
>> .../devicetree/bindings/arm/msm/qcom,kpss-gcc.txt | 44 +++
>> .../devicetree/bindings/clock/qcom,hfpll.txt | 60 ++++
>> .../devicetree/bindings/clock/qcom,krait-cc.txt | 34 ++
>> .../{kryo-cpufreq.txt => qcom-nvmem-cpufreq.txt} | 7 +-
>> arch/arm/common/Kconfig | 3 +
>> arch/arm/common/Makefile | 1 +
>> arch/arm/common/krait-l2-accessors.c | 48 +++
>> arch/arm/include/asm/krait-l2-accessors.h | 9 +
>> drivers/clk/qcom/Kconfig | 28 ++
>> drivers/clk/qcom/Makefile | 5 +
>> drivers/clk/qcom/clk-hfpll.c | 244 +++++++++++++
>> drivers/clk/qcom/clk-hfpll.h | 44 +++
>> drivers/clk/qcom/clk-krait.c | 126 +++++++
>> drivers/clk/qcom/clk-krait.h | 40 +++
>> drivers/clk/qcom/gcc-ipq806x.c | 82 +++++
>> drivers/clk/qcom/gcc-msm8960.c | 172 +++++++++
>> drivers/clk/qcom/hfpll.c | 96 +++++
>> drivers/clk/qcom/kpss-xcc.c | 87 +++++
>> drivers/clk/qcom/krait-cc.c | 397 +++++++++++++++++++++
>> drivers/cpufreq/Kconfig.arm | 6 +-
>> drivers/cpufreq/Makefile | 2 +-
>> drivers/cpufreq/cpufreq-dt-platdev.c | 5 +
>> drivers/cpufreq/qcom-cpufreq-kryo.c | 232 ------------
>> drivers/cpufreq/qcom-cpufreq-nvmem.c | 387 ++++++++++++++++++++
>> include/dt-bindings/clock/qcom,gcc-msm8960.h | 2 +
>> 26 files changed, 1941 insertions(+), 239 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,kpss-gcc.txt
>> create mode 100644 Documentation/devicetree/bindings/clock/qcom,hfpll.txt
>> create mode 100644 Documentation/devicetree/bindings/clock/qcom,krait-cc.txt
>> rename Documentation/devicetree/bindings/opp/{kryo-cpufreq.txt => qcom-nvmem-cpufreq.txt} (98%)
>> create mode 100644 arch/arm/common/krait-l2-accessors.c
>> create mode 100644 arch/arm/include/asm/krait-l2-accessors.h
>> create mode 100644 drivers/clk/qcom/clk-hfpll.c
>> create mode 100644 drivers/clk/qcom/clk-hfpll.h
>> create mode 100644 drivers/clk/qcom/clk-krait.c
>> create mode 100644 drivers/clk/qcom/clk-krait.h
>> create mode 100644 drivers/clk/qcom/hfpll.c
>> create mode 100644 drivers/clk/qcom/kpss-xcc.c
>> create mode 100644 drivers/clk/qcom/krait-cc.c
>> delete mode 100644 drivers/cpufreq/qcom-cpufreq-kryo.c
>> create mode 100644 drivers/cpufreq/qcom-cpufreq-nvmem.c
>>
>

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