spacemit: introduce P1 PMIC support

The SpacemiT P1 is an I2C-controlled PMIC that implements 6 buck
converters and 12 LDOs.  It contains a load switch, ADC channels,
GPIOs, a real-time clock, and a watchdog timer.

This series introduces a multifunction driver for the P1 PMIC as
well as drivers for its regulators and RTC.

After a sequence of attempts to add a new "max_register" value
to the simple_mfd_data structure in a way that would hopefully
be useful, we have reverted to the solution that was originally
proposed, which simply defines a regmap_config containing that
value along with reg_bits and val_bits (both 8).

This version removes the second patch, which contained the added
code to support the simple_mfd_data->max_register field.  It
also addresses a dependency issue in patch 4 (now 3) that was
pointed out by the Intel kernel test robot.

Note:  Yixun Lan suggested privately that I ensure the I2C_K1
config option gets enabled, but I'm going to do that as a
follow-on patch.

					-Alex

This series is available here:
  https://github.com/riscstar/linux/tree/outgoing/pmic-v11

Between version 9 and version 10:
  - Abandon trying to implement a simple_mfd_data->max_register field
  - Fix a missing dependency pointed out by the kernel test robot

Here is version 10 of this series:
  https://lore.kernel.org/lkml/20250726131003.3137282-1-eld...

Between version 9 and version 10:
  - The #address-cells and #size-cells for the i2c8 DTS node
    were moved into its primary definition in "k1.dtsi".
  - The interrupts property for the i2c8 DTS node was moved
    below its clock-related properties.
  - The status property in the pmic@41 DTS node was dropped.
  - The function that provides the regmap_config structure
    to use was reworked a bit.
  - A new function was added to free the regmap_config
    structure after it's no longer needed.

Here is version 9 of this series:
  https://lore.kernel.org/lkml/20250724202511.499288-1-elde...

Between version 8 and version 9:
  - The max_config value is always used if it is provided with the
    simple_mfd_data structure.
  - The regmap_config structure used is allocated dynamically if
    necessary; otherwise regmap_config_8r_8v is used.
  - A small duplicated comment is removed

Here is version 8 of this series:
  https://lore.kernel.org/lkml/20250710175107.1280221-1-eld...

More complete history is available at that link.

Alex Elder (7):
  dt-bindings: mfd: add support the SpacemiT P1 PMIC
  mfd: simple-mfd-i2c: add SpacemiT P1 support
  regulator: spacemit: support SpacemiT P1 regulators
  rtc: spacemit: support the SpacemiT P1 RTC
  riscv: dts: spacemit: enable the i2c8 adapter
  riscv: dts: spacemit: define fixed regulators
  riscv: dts: spacemit: define regulator constraints

 .../devicetree/bindings/mfd/spacemit,p1.yaml  |  86 +++++++++
 .../boot/dts/spacemit/k1-bananapi-f3.dts      | 135 ++++++++++++++
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi  |   7 +
 arch/riscv/boot/dts/spacemit/k1.dtsi          |  13 ++
 drivers/mfd/Kconfig                           |  11 ++
 drivers/mfd/simple-mfd-i2c.c                  |  18 ++
 drivers/regulator/Kconfig                     |  13 ++
 drivers/regulator/Makefile                    |   1 +
 drivers/regulator/spacemit-p1.c               | 157 ++++++++++++++++
 drivers/rtc/Kconfig                           |  10 ++
 drivers/rtc/Makefile                          |   1 +
 drivers/rtc/rtc-spacemit-p1.c                 | 167 ++++++++++++++++++
 12 files changed, 619 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/spacemit,p1.yaml
 create mode 100644 drivers/regulator/spacemit-p1.c
 create mode 100644 drivers/rtc/rtc-spacemit-p1.c


base-commit: b9ddaa95fd283bce7041550ddbbe7e764c477110
-- 
2.48.1