[PATCH v1 00/30] Introduce core voltage scaling for NVIDIA Tegra20/30 SoCs

[Dmitry Osipenko]

Introduce core voltage scaling for NVIDIA Tegra20/30 SoCs, which reduces
power consumption and heating of the Tegra chips. Tegra SoC has multiple
hardware units which belong to a core power domain of the SoC and share
the core voltage. The voltage must be selected in accordance to a minimum
requirement of every core hardware unit.

The minimum core voltage requirement depends on:

  1. Clock enable state of a hardware unit.
  2. Clock frequency.
  3. Unit's internal idling/active state.

This series is tested on Acer A500 (T20), AC100 (T20), Nexus 7 (T30) and
Ouya (T30) devices. I also added voltage scaling to the Ventana (T20) and
Cardhu (T30) boards which are tested by NVIDIA's CI farm. Tegra30 is now up
to 5C cooler on Nexus 7 and stays cool on Ouya (instead of becoming burning
hot) while system is idling. It should be possible to improve this further
by implementing a more advanced power management features for the kernel
drivers.

The DVFS support is opt-in for all boards, meaning that older DTBs will
continue to work like they did it before this series. It should be possible
to easily add the core voltage scaling support for Tegra114+ SoCs based on
this grounding work later on, if anyone will want to implement it.

WARNING(!) This series is made on top of the memory interconnect patches
           which are currently under review [1]. The Tegra EMC driver
           and devicetree-related patches need to be applied on top of
           the ICC series.

[1] https://patchwork.ozlabs.org/project/linux-tegra/list/?series=212196

Dmitry Osipenko (30):
  dt-bindings: host1x: Document OPP and voltage regulator properties
  dt-bindings: mmc: tegra: Document OPP and voltage regulator properties
  dt-bindings: pwm: tegra: Document OPP and voltage regulator properties
  media: dt: bindings: tegra-vde: Document OPP and voltage regulator
    properties
  dt-binding: usb: ci-hdrc-usb2:  Document OPP and voltage regulator
    properties
  dt-bindings: usb: tegra-ehci: Document OPP and voltage regulator
    properties
  soc/tegra: Add sync state API
  soc/tegra: regulators: Support Tegra SoC device sync state API
  soc/tegra: regulators: Fix lockup when voltage-spread is out of range
  regulator: Allow skipping disabled regulators in
    regulator_check_consumers()
  drm/tegra: dc: Support OPP and SoC core voltage scaling
  drm/tegra: gr2d: Correct swapped device-tree compatibles
  drm/tegra: gr2d: Support OPP and SoC core voltage scaling
  drm/tegra: gr3d: Support OPP and SoC core voltage scaling
  drm/tegra: hdmi: Support OPP and SoC core voltage scaling
  gpu: host1x: Support OPP and SoC core voltage scaling
  mmc: sdhci-tegra: Support OPP and core voltage scaling
  pwm: tegra: Support OPP and core voltage scaling
  media: staging: tegra-vde: Support OPP and SoC core voltage scaling
  usb: chipidea: tegra: Support OPP and SoC core voltage scaling
  usb: host: ehci-tegra: Support OPP and SoC core voltage scaling
  memory: tegra20-emc: Support Tegra SoC device state syncing
  memory: tegra30-emc: Support Tegra SoC device state syncing
  ARM: tegra: Add OPP tables for Tegra20 peripheral devices
  ARM: tegra: Add OPP tables for Tegra30 peripheral devices
  ARM: tegra: ventana: Add voltage supplies to DVFS-capable devices
  ARM: tegra: paz00: Add voltage supplies to DVFS-capable devices
  ARM: tegra: acer-a500: Add voltage supplies to DVFS-capable devices
  ARM: tegra: cardhu-a04: Add voltage supplies to DVFS-capable devices
  ARM: tegra: nexus7: Add voltage supplies to DVFS-capable devices

 .../display/tegra/nvidia,tegra20-host1x.txt   |  56 +++
 .../bindings/media/nvidia,tegra-vde.txt       |  12 +
 .../bindings/mmc/nvidia,tegra20-sdhci.txt     |  12 +
 .../bindings/pwm/nvidia,tegra20-pwm.txt       |  13 +
 .../devicetree/bindings/usb/ci-hdrc-usb2.txt  |   4 +
 .../bindings/usb/nvidia,tegra20-ehci.txt      |   2 +
 .../boot/dts/tegra20-acer-a500-picasso.dts    |  30 +-
 arch/arm/boot/dts/tegra20-paz00.dts           |  40 +-
 .../arm/boot/dts/tegra20-peripherals-opp.dtsi | 386 ++++++++++++++++
 arch/arm/boot/dts/tegra20-ventana.dts         |  65 ++-
 arch/arm/boot/dts/tegra20.dtsi                |  14 +
 .../tegra30-asus-nexus7-grouper-common.dtsi   |  23 +
 arch/arm/boot/dts/tegra30-cardhu-a04.dts      |  44 ++
 .../arm/boot/dts/tegra30-peripherals-opp.dtsi | 415 ++++++++++++++++++
 arch/arm/boot/dts/tegra30.dtsi                |  13 +
 drivers/gpu/drm/tegra/Kconfig                 |   1 +
 drivers/gpu/drm/tegra/dc.c                    | 138 +++++-
 drivers/gpu/drm/tegra/dc.h                    |   5 +
 drivers/gpu/drm/tegra/gr2d.c                  | 140 +++++-
 drivers/gpu/drm/tegra/gr3d.c                  | 136 ++++++
 drivers/gpu/drm/tegra/hdmi.c                  |  63 ++-
 drivers/gpu/host1x/Kconfig                    |   1 +
 drivers/gpu/host1x/dev.c                      |  87 ++++
 drivers/memory/tegra/tegra20-emc.c            |   8 +-
 drivers/memory/tegra/tegra30-emc.c            |   8 +-
 drivers/mmc/host/Kconfig                      |   1 +
 drivers/mmc/host/sdhci-tegra.c                |  70 ++-
 drivers/pwm/Kconfig                           |   1 +
 drivers/pwm/pwm-tegra.c                       |  84 +++-
 drivers/regulator/core.c                      |  12 +-
 .../soc/samsung/exynos-regulator-coupler.c    |   2 +-
 drivers/soc/tegra/common.c                    | 152 ++++++-
 drivers/soc/tegra/regulators-tegra20.c        |  25 +-
 drivers/soc/tegra/regulators-tegra30.c        |  30 +-
 drivers/staging/media/tegra-vde/Kconfig       |   1 +
 drivers/staging/media/tegra-vde/vde.c         | 127 ++++++
 drivers/staging/media/tegra-vde/vde.h         |   1 +
 drivers/usb/chipidea/Kconfig                  |   1 +
 drivers/usb/chipidea/ci_hdrc_tegra.c          |  79 ++++
 drivers/usb/host/Kconfig                      |   1 +
 drivers/usb/host/ehci-tegra.c                 |  79 ++++
 include/linux/regulator/coupler.h             |   6 +-
 include/soc/tegra/common.h                    |  22 +
 43 files changed, 2360 insertions(+), 50 deletions(-)

-- 
2.27.0