[v5,0/5] UFS: Add OPP support

Hi,

This series adds OPP (Operating Points) support to UFSHCD driver.

Motivation behind adding OPP support is to scale both clocks as well as
regulators/performance state dynamically. Currently, UFSHCD just scales
clock frequency during runtime with the help of "freq-table-hz" property
defined in devicetree. With the addition of OPP tables in devicetree (as
done for Qcom SDM845 and SM8250 SoCs in this series) UFSHCD can now scale
both clocks and performance state of power domain which helps in power
saving.

For the addition of OPP support to UFSHCD, there are changes required to
the OPP framework and devfreq drivers. The OPP framework changes are already
merged and the devfreq change is added in this series.

Credits
=======

This series is a continuation of previous work by Krzysztof Kozlowski [1].

Testing
=======

This series is tested on 96Boards RB3 (SDM845 SoC) and RB5 (SM8250 SoC)
development boards.

Merging Strategy
================

Since the devfreq patch got an Ack from the maintainer, either it can be merged
to scsi tree with rest of the patches or merged separately through devfreq tree.

Thanks,
Mani

[1] https://lore.kernel.org/all/20220513061347.46480-1-krzysztof.kozlowski@linaro.org/

Changes in v5:

* Dropped the devfreq patch since it got applied
* Fixed the bindings issue reported by DT bot
* Rebased on top of mkp/scsi/for-next

Changes in v4:

* Rebased on top of v6.6-rc3

Changes in v3:

* Rebased on top of linux-next/master tag: next-20230731
* Dropped the already applied patches (dts, opp binding and framework)
* Moved the interconnect patches to a separate series:
  https://lore.kernel.org/linux-scsi/20230731145020.41262-1-manivannan.sadhasivam@linaro.org/
* Moved ufshcd_opp_config_clks() API to ufshcd.c to fix the build failure
  reported by Kbuild bot: https://lore.kernel.org/all/202307210542.KoLHRbU6-lkp@intel.com/
* Collected Acks
* v2: https://lore.kernel.org/all/20230720054100.9940-1-manivannan.sadhasivam@linaro.org/

Changes in v2:

* Added more description to the bindings patch 2/15
* Fixed dev_pm_opp_put() usage in patch 10/15
* Added a new patch for adding enums for UFS lanes 14/15
* Changed the icc variables to mem_bw and cfg_bw and used
  the enums for gears and lanes in bw_table
* Collected review tags
* Added SCSI list and folks
* Removed duplicate patches

Krzysztof Kozlowski (2):
  dt-bindings: ufs: common: add OPP table
  arm64: dts: qcom: sdm845: Add OPP table support to UFSHC

Manivannan Sadhasivam (3):
  scsi: ufs: core: Add OPP support for scaling clocks and regulators
  scsi: ufs: host: Add support for parsing OPP
  arm64: dts: qcom: sm8250: Add OPP table support to UFSHC

 .../devicetree/bindings/ufs/ufs-common.yaml   |  35 +++-
 arch/arm64/boot/dts/qcom/sdm845.dtsi          |  42 +++-
 arch/arm64/boot/dts/qcom/sm8250.dtsi          |  39 +++-
 drivers/ufs/core/ufshcd.c                     | 179 ++++++++++++++----
 drivers/ufs/host/ufshcd-pltfrm.c              |  78 ++++++++
 include/ufs/ufshcd.h                          |   7 +
 6 files changed, 325 insertions(+), 55 deletions(-)

On 11/10/2023 14:25, Manivannan Sadhasivam wrote:
> From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> Except scaling UFS and bus clocks, it's necessary to scale also the
> voltages of regulators or power domain performance state levels.  Adding
> Operating Performance Points table allows to adjust power domain
> performance state, depending on the UFS clock speed.
> 
> OPPv2 deprecates previous property limited to clock scaling:
> freq-table-hz.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  .../devicetree/bindings/ufs/ufs-common.yaml   | 35 +++++++++++++++++--
>  1 file changed, 32 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
> index bbaee4f5f7b2..1cb022cdc349 100644
> --- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
> +++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
> @@ -6,6 +6,7 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
>  
>  title: Common properties for Universal Flash Storage (UFS) Host Controllers
>  
> +

Drop blank line.

>  maintainers:
>    - Alim Akhtar <alim.akhtar@samsung.com>
>    - Avri Altman <avri.altman@wdc.com>
> @@ -20,11 +21,24 @@ properties:
>        items:
>          - description: Minimum frequency for given clock in Hz
>          - description: Maximum frequency for given clock in Hz
> +    deprecated: true
>      description: |
> +      Preferred is operating-points-v2.
> +
>        Array of <min max> operating frequencies in Hz stored in the same order
> -      as the clocks property. If this property is not defined or a value in the
> -      array is "0" then it is assumed that the frequency is set by the parent
> -      clock or a fixed rate clock source.
> +      as the clocks property. If either this property or operating-points-v2 is
> +      not defined or a value in the array is "0" then it is assumed that the
> +      frequency is set by the parent clock or a fixed rate clock source.
> +
> +  operating-points-v2:
> +    description:
> +      Preferred over freq-table-hz.
> +      If present, each OPP must contain array of frequencies stored in the same
> +      order for each clock.  If clock frequency in the array is "0" then it is
> +      assumed that the frequency is set by the parent clock or a fixed rate
> +      clock source.
> +
> +  opp-table: true

opp-table:
  type: object



Best regards,
Krzysztof