Add Richtek RT9471 3A battery charger support

From: ChiYuan Huang <cy_huang@richtek.com>

This patch set is to add Richtek RT9471 charger support.

The RT9471/D is a highly-integrated 3A switch mode battery charge management
and system power path management device for single cell Li-Ion and Li-polymer
battery. The low impedance power path optimizes switch-mode operation
efficiency, reduces battery charging time and extends battery life during
discharging phase.

Since v7:
- Add irq wakeup capable.
- Add missing header 'module.h' for MODULE_DEVICE_TABLE.

Since v6:
- Use 'ATTRIBUTE_GROUPS' macro to simplify the attribute coding.
- Explain more details for sysoff_enable attribute.

Since v5:
- Remove one line wrapper.
- Merge header content into source file, remove header file.
- Remove 'charge_term_enable' sysfs entry and merge it into
  'charge_term_current' property control.
- Change MODULE_LICENSE from 'GPL v2' to 'GPL'.
  Following by the below discussion
  https://lore.kernel.org/all/YxAVAt2eWB3NFlrk@google.com/
- Recover all the change in sysfs-class-power.
- New a sysfs-class-power-rt9471 file.
- Remove 'charge_term_enable' sysfs entry, directly integrate it in
  'charge_term_current' power supply property control.

Since v4:
- Remove the line for the owner field in driver.
- Add the documentation for sysfs entries.

Since v3:
- Move unevaluatedProperties line after $ref for binding patch.
- Add Reviewed-by tag for binding patch.

Since v2:
- Remove the properties for interrupt controller things in the binding documentation.
- Fix dtc error for typo, it's 'regulator-name', not 'regulator-compatible'.
- Add regulator min/max microamp to allow otg vbus current adjustable in example.
- Specify the active-level for charge-enable-gpios in binding example.
- Fix checkpatch error about 'foo * bar' to 'foo *bar' in psy_device_to_chip function.
- Specify the member name directly for the use of linear range.

ChiYuan Huang (3):
  dt-bindings: power: supply: Add Richtek RT9471 battery charger
  power: supply: rt9471: Add Richtek RT9471 charger driver
  Documentation: power: rt9471: Document exported sysfs entries

 Documentation/ABI/testing/sysfs-class-power-rt9471 |  32 +
 .../bindings/power/supply/richtek,rt9471.yaml      |  73 ++
 drivers/power/supply/Kconfig                       |  16 +
 drivers/power/supply/Makefile                      |   1 +
 drivers/power/supply/rt9471.c                      | 934 +++++++++++++++++++++
 5 files changed, 1056 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-power-rt9471
 create mode 100644 Documentation/devicetree/bindings/power/supply/richtek,rt9471.yaml
 create mode 100644 drivers/power/supply/rt9471.c

-- 
2.7.4