mfd: AXP20x: Add support for AXP202 and AXP209

During the merging of v6 several patches were left out. This v7 comprises all the patches that are still pending.

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AXP209 and AXP202 are the PMUs (Power Management Unit) used by A10, A13 and A20 SoCs and developed by X-Powers, a sister company of Allwinner. AXP20x comprises an adaptive USB-Compatible PWM charger, 2 BUCK DC-DC converters, 5 LDOs, multiple 12-bit ADCs of voltage, current and temperature as well as 4 configurable GPIOs.

This set of patches introduces the core driver and support for two different subsystems:
- Regulators
- PEK (Power Enable Key)

Changes since v1:

- Added a new standalone patch for defconfig

- MFD core:
* Removed axp,system-power-controller property

- Bindings documentation:
* Corrected description for dcdc-workmode property
* Removed unused axp20x-pek compatible

- Input misc PEK driver:
* Fixed seconds in lower case

- Regulators subsystem:
* Fixed axp20x_set_suspend_voltage()
* Switched to using multi-bit control for regulators
* When "regulators" node is not found driver doesn't quit
* Driver is now using devm_regulator_register()
* Added module_platform_driver() instead of subsys_initcall()

- DT:
* Added new DTSI for AXP209
* Added support for cubietruck and olinuxino-micro

Changes since v2:

- Added a new patch for multi_v7_defconfig to enable MFD core and subsystems

- DT:
* Dropped axp,system-power-controller property from DTS
* Moved compatible and interrupt-related properties from the DTSI file to the DTS board files

- Regulators subsystem:
* Deleted useless struct axp20x_regulators
* Added a warning when out of specs values are used for the dcdc frequency

- MFD core:
* Fixed coding style
* Removed IDs from device table for i2c

- Bindings documentation:
* Several corrections and fixes

Changes since v3:

- Removed x-powers-axp209.dtsi file
- Rewritten bindings document

- MFD core:
* Fixed casting
* Better comments / documentation

- Input misc PEK driver:
* Timings are now expressed in ms and the sysfs appies the closest possible value
* No more useless pretty-printing
* Removed devm_request_threaded_irq in favour of devm_request_any_context_irq
* Moved from input attributes to platform device attributes

- Regulators subsystem:
* Removed suspend mode (axp20x_set_suspend_voltage)
* Added regulators input supply

- DT:
* DTs doesn't include anymore the dtsi
* Added input supplies for regulators

Changes since v4:

- Removed regulator patches already applied / acked by Mark Brown

- Input misc PEK driver:
* Don't print anymore the "us" unit
* Added cleanup for attributes when unbindind the device
* Fixed error code returned when device_create_file() fails

- DT:
* Enable all the regulators on at boot-time
* Removed min and max microvolts for all the regulators but DCDC2
* Moved the axp_ipsout regulator outside the MFD node

- MFD core:
* The supply regulators are now specified in the MFD driver using regulator_bulk_register_supply_alias() and the .parent_supplies in the MFD cell

Changes since v5:
- Added ACKs
- Fixed compilation warning (reported by Hans De Goede)
- Vendor-prefixes are now sorted
- Removed DT patch

Carlo Caione (6):
mfd: AXP20x: Add bindings documentation
dt-bindings: add vendor-prefix for X-Powers
input: misc: Add driver for AXP20x Power Enable Key
input: misc: Add ABI docs for AXP20x PEK
ARM: sunxi: Add AXP20x support in defconfig
ARM: sunxi: Add AXP20x support multi_v7_defconfig

 .../ABI/testing/sysfs-driver-input-axp-pek         |  11 +
 Documentation/devicetree/bindings/mfd/axp20x.txt   |  93 +++++++
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 arch/arm/configs/multi_v7_defconfig                |   3 +
 arch/arm/configs/sunxi_defconfig                   |   3 +
 drivers/input/misc/Kconfig                         |  11 +
 drivers/input/misc/Makefile                        |   1 +
 drivers/input/misc/axp20x-pek.c                    | 281 +++++++++++++++++++++
 8 files changed, 404 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-input-axp-pek
 create mode 100644 Documentation/devicetree/bindings/mfd/axp20x.txt
 create mode 100644 drivers/input/misc/axp20x-pek.c