Add support for MT6392 PMIC

The MediaTek MT6392 PMIC is usually found on devices powered by the MT8516/MT8167 SoC and is yet another MT6323/MT6397 variant.

This series is mostly based around patches submitted a couple years ago by Fabien Parent and not merged and from Val Packett's submission from Jan 2025 that included extra cleanups, fixes, and a new dtsi file similar to ones that exist for other PMICs. Some comments weren't addressed and the series was ultimately not merged.

These patches enable four functions: keys, regulator, pinctrl and RTC. Mono speaker amp will follow later as I need to work further on the audio codec.

I added a handful of device tree improvements to fix some dtbs_check errors, added support for the pinctrl device and addressed the comments from last year's reviews.

Please note that patch 0006 and 0008 depend on patch 0005 as they need the registers.h file, but belong to different driver areas. I'm not sure if I'm supposed to squash them even if they belong to different driver areas of if it's fine like this. Any advice is welcome.

Patch 0009 also depends on patch 0003 because of mt6392-regulator.h.

The series has been tested on Xiaomi Mi Smart Clock X04G, on the Lenovo Smart Clock 2 CD-24502F, on Sony PlayStation Classic Mini SCPH-1000R and on the Lenovo Tab E7 TB-7104F.

Changes in v12:
- Rebased over v7.4-rc1;
- The patch to convert all mt6397 cells to MFD_CELL_OF was removed from the series, as it's not strictly relevant for mt6392 support. It has been submitted separately [14] and can be applied independently.
- Added the regulator-always-on properties and basic voltage restrictions for core regulators for Pumpkin boards to prevent boot failures (suggested by Sashiko).

Changes in v11 [13]:
- Removed the example from the PMIC binding, fixing some bisecting issues.

Changes in v10 [12]:
- Removed the fallback on mediatek,mt6323 in the MFD binding document and in the dtsi file. Suggested by Sashiko [11], thus removed the Reviewed-by tag provided by Kryzsztof Kozlowski in patch #1, version 9.

Changes in v9 [10]:
- Correct binding for vrtc as it does not support mode setting.

From Sashiko:
- Added missing include in MFD documentation example.
- Fixed constraints for regulator-initial-mode in regulator binding.
- Fixed wrong register write while setting LDO standby mode.
- Added missing pmic interrupt definition in the pumpkin-common include.

Changes in v8 [9]:
From reviewers:
- Added example code to the MFD device binding, removed it from the regulators docs.
- Added minItems/maxItems constraints on the regulator mode definitions, improved the mode constants.
- Fixed formatting issues in the regulator binding.
- Import the mt6392.dtsi file in pumpkin-common.dtsi, as it was originally meant in [8].

From sashiko:
- Added more explicit constraints on the regulator modes definitions.
- Use the appropriate modeget register for LDO regulators, Buck registers don't have the corresponding register according to the data sheet.
- Added the missing of_map_mode function.
- Removed some debugging code that had no use and masked error codes.

Changes in v7 [7]:
- Removed patch 0008 dependency on patch 0003.
- Reintroduced the regulator driver. In earlier revisions of this series, it was proposed to remove the dedicated compatible for the regulator device [3]. The driver does not use actually it, but it is not possible at this time to remove it from the bindings since it's a required property.

Making the regulator-required property conditional was NACKed in [5], with the suggestion to create a separate binding altogether for devices that do not require the compatible property. I tried implementing this, but since the parent device needs to be declared as compatible with mt6323, it leads to a warning in dt_binding_check since mt6323 would be declared as a compatible in both mt6392 and mt6397.

In the end the only regulator driver from the mt6397 documentation that still declares an of_match is mt6397-regulator and it does not seem to be necessary, so it should be possible to remove it and make the regulator compatible optional for all regulators, but that change would probably deserve its own separate patch series.

Changes in v6 [6]:
- Dropped the regulators driver for the moment
- Explained the FCHR key name origin in the commit message
- Introduced the MFD_CELL_* macro in the sub-devices definitions. A separate, independent commit introduced MFD_CELL_* to all the subdevices in the mt6397-core.c file for consistency
- Replaced of_device_get_match_data with device_get_match_data
- Removed the mfd_match_data enum in favor of the preexisting chip_id enum
- Adjusted the error message if the device is unsupported

Changes in v5 [5]:
- Double checked regulator driver with data sheet and Android sources. The data sheet I have misses a lot of register descriptions, but Android sources have been helpful to fill the gaps
- Reintroduced the required attribute for the regulator compatible in the bindings
- Fixed the missing reference to the MT6392 schema
- Fixed casts/unused vars reported by kernel test robot
- Removed Reviewed-by tags from the regulator patches as they have been modified in this version

Changes in v4 [4]:
- Dropped usage of the regulator compatible
- Fixed commit messages text to properly reference the target subsystem
- Added supply rails to the regulator
- Reworked the regulator schema and PMIC dtsi. Now all supplies are documented and the schema no longer includes voltage information
- Removed redundant ldo- / buck- prefixes
- Renamed the pinfunc header to mediatek,mt6392-pinfunc.h
- Modified the MFD driver to use a simple identifier in the of_match data properties

Changes in v3 [3]:
- Added pinctrl device
- Changed mt6397-rtc fallback to mt6323-rtc
- Added schema for regulators
- Fixed checkpatch issues

Changes in v2 [2]:
- Replaced explicit compatibles with fallbacks

Initial version: [1]

[1] https://lore.kernel.org/linux-mediatek/[email protected]/
[2] https://lore.kernel.org/linux-mediatek/[email protected]/
[3] https://lore.kernel.org/linux-mediatek/[email protected]/
[4] https://lore.kernel.org/linux-mediatek/[email protected]/
[5] https://lore.kernel.org/linux-mediatek/[email protected]/
[6] https://lore.kernel.org/linux-mediatek/[email protected]/
[7] https://lore.kernel.org/linux-mediatek/[email protected]/
[8] https://lore.kernel.org/linux-mediatek/[email protected]/
[9] https://lore.kernel.org/linux-mediatek/[email protected]/
[10] https://lore.kernel.org/linux-mediatek/[email protected]/
[11] https://sashiko.dev/#/message/20260820125850.3B34D1F000E9%40smtp.kernel.org
[12] https://lore.kernel.org/linux-mediatek/[email protected]/
[13] https://lore.kernel.org/linux-mediatek/[email protected]/
[14] https://lore.kernel.org/linux-mediatek/[email protected]/

Fabien Parent (3):
dt-bindings: input: mtk-pmic-keys: Add MT6392 PMIC keys
mfd: mt6397: Add support for MT6392 PMIC
regulator: Add MediaTek MT6392 regulator

Luca Leonardo Scorcia (3):
dt-bindings: mfd: mt6397: Add MT6392 PMIC
regulator: dt-bindings: Add MediaTek MT6392 PMIC
pinctrl: mediatek: mt6397: Add MediaTek MT6392

Val Packett (2):
input: keyboard: mtk-pmic-keys: Add MT6392 support
arm64: dts: mediatek: Add MediaTek MT6392 PMIC dtsi

 .../bindings/input/mediatek,pmic-keys.yaml    |   1 +
 .../bindings/mfd/mediatek,mt6397.yaml         |   6 +
 .../regulator/mediatek,mt6392-regulator.yaml  | 112 +++
 arch/arm64/boot/dts/mediatek/mt6392.dtsi      | 145 ++++
 .../boot/dts/mediatek/pumpkin-common.dtsi     |  82 ++
 drivers/input/keyboard/mtk-pmic-keys.c        |  18 +
 drivers/mfd/mt6397-core.c                     |  97 ++-
 drivers/mfd/mt6397-irq.c                      |   8 +
 drivers/pinctrl/mediatek/pinctrl-mt6397.c     |  37 +-
 drivers/pinctrl/mediatek/pinctrl-mtk-mt6392.h |  64 ++
 drivers/regulator/Kconfig                     |   9 +
 drivers/regulator/Makefile                    |   1 +
 drivers/regulator/mt6392-regulator.c          | 764 ++++++++++++++++++
 .../regulator/mediatek,mt6392-regulator.h     |  23 +
 include/linux/mfd/mt6392/core.h               |  43 +
 include/linux/mfd/mt6392/registers.h          | 488 +++++++++++
 include/linux/mfd/mt6397/core.h               |   1 +
 include/linux/regulator/mt6392-regulator.h    |  42 +
 18 files changed, 1913 insertions(+), 28 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/regulator/mediatek,mt6392-regulator.yaml
 create mode 100644 arch/arm64/boot/dts/mediatek/mt6392.dtsi
 create mode 100644 drivers/pinctrl/mediatek/pinctrl-mtk-mt6392.h
 create mode 100644 drivers/regulator/mt6392-regulator.c
 create mode 100644 include/dt-bindings/regulator/mediatek,mt6392-regulator.h
 create mode 100644 include/linux/mfd/mt6392/core.h
 create mode 100644 include/linux/mfd/mt6392/registers.h
 create mode 100644 include/linux/regulator/mt6392-regulator.h

2.43.0