[PATCH v22 0/7] soc: mediatek: SVS: introduce MTK SVS engine

[Roger Lu]

The Smart Voltage Scaling(SVS) engine is a piece of hardware
which calculates suitable SVS bank voltages to OPP voltage table.
Then, DVFS driver could apply those SVS bank voltages to PMIC/Buck
when receiving OPP_EVENT_ADJUST_VOLTAGE.

1. SVS driver uses OPP adjust event in [1] to update OPP table voltage part.
2. SVS driver gets thermal/GPU device by node [2][3] and CPU device by get_cpu_device().
After retrieving subsys device, SVS driver calls device_link_add() to make sure probe/suspend callback priority.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm.git/commit/?h=opp/linux-next&id=25cb20a212a1f989385dfe23230817e69c62bee5
[2] https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm.git/commit/?h=opp/linux-next&id=b325ce39785b1408040d90365a6ab1aa36e94f87
[3] https://git.kernel.org/pub/scm/linux/kernel/git/matthias.bgg/linux.git/commit/?h=v5.16-next/dts64&id=a8168cebf1bca1b5269e8a7eb2626fb76814d6e2

change since v21:
- Rebase to kernel 5.17-rc1.
- Remove unnecessary "maxItems" from nvmem-cells in mtk-svs.yaml.
- Move svs_platform_data definition to the beginning of the file for increased readability.
- For better performance purpose, we add "thermal_zone_device" memeber in svs bank structure and cache it at driver probe time.
- Remove svs_get_zone_temperature() and call thermal_zone_get_temp() directly when we needs to read temperature.
- Drop mt8192 svs node patch and we'll submit another complete mt8192.dtsi patch including mt8192 svs node.
- Replace mask7_0 with GENMASK macro and bits8/reg_bytes with corresponding definition.
- Separate definition with "register common configuration" and "related setting" for better categorization.
- Remove redundant codes including "svsb->suspended concept" and refine comments.
- Move devm_regulator_get_optional() to svs_bank_resource_setup() for better understanding.

Roger Lu (7):
  [v22,1/7] dt-bindings: soc: mediatek: add mtk svs dt-bindings
  [v22,2/7] arm64: dts: mt8183: add svs device information
  [v22,3/7] soc: mediatek: SVS: introduce MTK SVS engine
  [v22,4/7] soc: mediatek: SVS: add monitor mode
  [v22,5/7] soc: mediatek: SVS: add debug commands
  [v22,6/7] dt-bindings: soc: mediatek: add mt8192 svs dt-bindings
  [v22,7/7] soc: mediatek: SVS: add mt8192 SVS GPU driver

 .../bindings/soc/mediatek/mtk-svs.yaml        |   91 +
 arch/arm64/boot/dts/mediatek/mt8183.dtsi      |   16 +
 drivers/soc/mediatek/Kconfig                  |   10 +
 drivers/soc/mediatek/Makefile                 |    1 +
 drivers/soc/mediatek/mtk-svs.c                | 2439 +++++++++++++++++
 5 files changed, 2557 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mtk-svs.yaml
 create mode 100644 drivers/soc/mediatek/mtk-svs.c