[PATCH v10] cpufreq: mediatek-hw: Add support for Mediatek cpufreq HW driver

[Matthias Brugger]

On 29/12/2020 07:17, Hector Yuan wrote:
> The CPUfreq HW present in some Mediatek chipsets offloads the steps necessary for changing the frequency of CPUs. 
> The driver implements the cpufreq driver interface for this hardware engine. 
> This patch depends on MT6779 DTS patchset[1] submitted by Hanks Chen.

This dependency got resolved, the patch is mainline since v5.11. Please delete
it in further revisions of the patch set to minimize confusion.

Thanks!

> 
> From v8 to v9, there are three more modifications.
> 1. Based on patchset[2], align binding with scmi for performance domain.
> 2. Add the CPUFREQ fast switch function support and define DVFS latency.
> 3. Based on patchser[3], add energy model API parameter for mW.
> 
> From v7 to v8, there are three more patches based on patchset v8[4].
> This patchset is about to register power table to Energy model for EAS and thermal usage.
> 1. EM CPU power table
> - Register energy model table for EAS and thermal cooling device usage.
> - Read the coresponding LUT for power table.
> 2. SVS initialization
> - The SVS(Smart Voltage Scaling) engine is a hardware which is
>   used to calculate optimized voltage values for CPU power domain.
>   DVFS driver could apply those optimized voltage values to reduce power consumption.
> - Driver will polling if HW engine is done for SVS initialization.
>   After that, driver will read power table and register it to EAS.
> - CPUs must be in power on state when doing SVS. Use pm_qos to block cpu-idle state for SVS initializing.
> 3. Cooling device flag
> - Add cooling device flag for thermal
> 
> [1]  https://lkml.org/lkml/2020/8/4/1094
> [2]  https://lore.kernel.org/lkml/20201116181356.804590-1-sudeep.holla@arm.com/
> [3]  https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?h=linux-next&id=c250d50fe2ce627ca9805d9c8ac11cbbf922a4a6
> [4]  https://lkml.org/lkml/2020/9/23/384
> 
> 
> Hector.Yuan (2):
>   cpufreq: mediatek-hw: Add support for CPUFREQ HW
>   dt-bindings: cpufreq: add bindings for MediaTek cpufreq HW
> 
>  .../bindings/cpufreq/cpufreq-mediatek-hw.yaml      |  116 ++++++
>  drivers/cpufreq/Kconfig.arm                        |   12 +
>  drivers/cpufreq/Makefile                           |    1 +
>  drivers/cpufreq/mediatek-cpufreq-hw.c              |  370 ++++++++++++++++++++
>  4 files changed, 499 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-mediatek-hw.yaml
>  create mode 100644 drivers/cpufreq/mediatek-cpufreq-hw.c
>