[PATCH v21 0/8] 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 v20:
- Rebase to kernel 5.16-rc1
- Separate mt8183 svs as two patches for minimun version support. patch1 (init01 ~ init02) and patch2 (mon mode).
- Remove unused flags in each patch.
- Move @SVSB_PHASE_ERROR before @SVSB_PHASE_INIT01 for order correctness.
- Reorder the struct member comment and coding for the consistenty. Also revise the ambiguous comments.
- Use [writel,readl]_relaxed instead of [writel,readl].
- Fix ->efuse_parsing() not return "false" mistake.
- Move more commen settings out of svs bank structure for shrinking data structure size.
- Split up the "get platform data" and "platform probe" behavior.
- Change the naming of "svs_is_supported()" to "svs_is_efuse_data_correct()" for better understanding.
- SVSB_DC_SIGNED_BIT is configured as BIT(15) instead of 0x8000.
- Add the missing variables comments back in the structure.
- Add define "MAX_OPP_ENTRIES" for representing opp total count.
- Add more kernel log description when error happens.
- Add missing error handler when using nvmem_cell_read().

Roger Lu (8):
  [v21,1/8] dt-bindings: soc: mediatek: add mtk svs dt-bindings
  [v21,2/8] arm64: dts: mt8183: add svs device information
  [v21,3/8] soc: mediatek: SVS: introduce MTK SVS engine
  [v21,4/8] soc: mediatek: SVS: add monitor mode
  [v21,5/8] soc: mediatek: SVS: add debug commands
  [v21,6/8] dt-bindings: soc: mediatek: add mt8192 svs dt-bindings
  [v21,7/8] arm64: dts: mt8192: add svs device information
  [v21,8/8] soc: mediatek: SVS: add mt8192 SVS GPU driver

 .../bindings/soc/mediatek/mtk-svs.yaml        |   92 +
 arch/arm64/boot/dts/mediatek/mt8183.dtsi      |   16 +
 arch/arm64/boot/dts/mediatek/mt8192.dtsi      |   39 +
 drivers/soc/mediatek/Kconfig                  |   10 +
 drivers/soc/mediatek/Makefile                 |    1 +
 drivers/soc/mediatek/mtk-svs.c                | 2461 +++++++++++++++++
 6 files changed, 2619 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mtk-svs.yaml
 create mode 100644 drivers/soc/mediatek/mtk-svs.c