Re: [PATCH v4 00/13] Support CPU frequency scaling on QCS404

[Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>]

On 7/31/19 22:29, Jorge Ramirez-Ortiz wrote:
> The following patchset enables CPU frequency scaling support on the
> QCS404 (with dynamic voltage scaling).
> 
> It is important to notice that this functionality will be superseded
> by Core Power Reduction (CPR), a more accurate form of AVS found on
> certain Qualcomm SoCs.
> 
> Some of the changes required to support CPR do conflict with the
> configuration required for CPUFreq.
> 
> In particular, the following commit for CPR - already merged - will
> need to be reverted in order to enable CPUFreq.
> 
>    Author: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
>    Date:   Thu Jul 25 12:41:36 2019 +0200
>        cpufreq: Add qcs404 to cpufreq-dt-platdev blacklist
>     
> Patch 8 "clk: qcom: hfpll: CLK_IGNORE_UNUSED" is a bit controversial;
> in this platform, this PLL provides the clock signal to a CPU
> core. But in others it might not.
> 
> We opted for the minimal ammount of changes without affecting the
> default functionality: simply bypassing the COMMON_CLK_DISABLE_UNUSED
> framework and letting the firwmare chose whether to enable or disable
> the clock at boot. However maybe a DT property and marking the clock
> as critical would be more appropriate for this PLL. we'd appreciate the
> maintainer's input on this topic.
> 
> v2:
>    - dts: ms8916: apcs mux/divider: new bindings
>      (the driver can still support the old bindings)
> 
>    - qcs404.dtsi
>      fix apcs-hfpll definition
>      fix cpu_opp_table definition
> 
>    - GPLL0_AO_OUT operating frequency
>      define new alpha_pll_fixed_ops to limit the operating frequency
> 
> v3:
>   - qcom-apcs-ipc-mailbox
>     replace goto to ease readability
> 
>   - apcs-msm8916.c
>     rework patch to use of_clk_parent_fill
> 
>   - hfpll.c
>     add relevant comments to the code
> 
>   - qcs404.dtsi
>     add voltage scaling support
> 
> v4:
>  - squash OPP definition and DVFS enablement in dts
>    (patches 10 and 13 in previous version)
>    
>  - qcom-apcs-ipc-mailbox
>    replace return condition for readability
>    
>  - answer one question on CLK_IGNORE_UNUSED in mailing list
> 
> Jorge Ramirez-Ortiz, Niklas Cassel (13):
>   clk: qcom: gcc: limit GPLL0_AO_OUT operating frequency
>   mbox: qcom: add APCS child device for QCS404
>   mbox: qcom: replace integer with valid macro
>   dt-bindings: mailbox: qcom: Add clock-name optional property
>   clk: qcom: apcs-msm8916: get parent clock names from DT
>   clk: qcom: hfpll: get parent clock names from DT
>   clk: qcom: hfpll: register as clock provider
>   clk: qcom: hfpll: CLK_IGNORE_UNUSED
>   arm64: dts: qcom: msm8916: Add the clocks for the APCS mux/divider
>   arm64: dts: qcom: qcs404: Add HFPLL node
>   arm64: dts: qcom: qcs404: Add the clocks for APCS mux/divider
>   arm64: dts: qcom: qcs404: Add DVFS support
>   arm64: defconfig: Enable HFPLL
> 
>  .../mailbox/qcom,apcs-kpss-global.txt         | 24 +++++++++--
>  arch/arm64/boot/dts/qcom/msm8916.dtsi         |  3 +-
>  arch/arm64/boot/dts/qcom/qcs404.dtsi          | 43 +++++++++++++++++++
>  arch/arm64/configs/defconfig                  |  1 +
>  drivers/clk/qcom/apcs-msm8916.c               | 23 ++++++++--
>  drivers/clk/qcom/clk-alpha-pll.c              |  8 ++++
>  drivers/clk/qcom/clk-alpha-pll.h              |  1 +
>  drivers/clk/qcom/gcc-qcs404.c                 |  2 +-
>  drivers/clk/qcom/hfpll.c                      | 25 ++++++++++-
>  drivers/mailbox/qcom-apcs-ipc-mailbox.c       | 11 +++--
>  10 files changed, 128 insertions(+), 13 deletions(-)
> 

any feedback on this set?

TIA