[RFC PATCH 0/3] UP Squared board drivers

[Javier Arteaga <javier@emutex.com>]

Hi all,

This series adds platform support for AAEON's UP Squared, a x86 SBC
based on Apollo Lake [1]. Specifically, it enables control for the board
pin headers and for the LEDs, as both of these features are only
available behind a FPGA-based platform controller.

This is structured around a MFD driver that provides a regmap interface
to that platform controller to each MFD cell.

The series is carved out from an out-of-tree support patchset, initially
written by Dan O'Donovan for the original UP Board [2] and then extended
through the past year to support new entries in the lineup (UP Board, UP
Squared and UP Core) [3].

Here we only submit support for UP Squared to simplify review. Still,
the driver is designed so that it can easily gain support for the other
boards.

Questions:

* Is MFD the right fit for the platform controller?
  The intention here is to encapsulate the custom GPIO-bitbanged control
  protocol by sharing the regmap between the drivers.

* Is our use of two chained pinctrls (in patch 3/3) valid?

Thank you!

[1]: http://www.up-board.org/upsquared/specifications-up2/
[2]: https://lkml.kernel.org/r/1467648434-29080-1-git-send-email-dan@emutex.com
[3]: https://github.com/emutex/ubilinux-kernel/commits/upboard-4.9

Javier Arteaga (3):
  mfd: upboard: Add UP2 platform controller driver
  leds: upboard: Add LED support
  pinctrl: upboard: Add pinctrl and gpio driver

 drivers/leds/Kconfig              |  10 +
 drivers/leds/Makefile             |   1 +
 drivers/leds/leds-upboard.c       |  87 +++++
 drivers/mfd/Kconfig               |  17 +
 drivers/mfd/Makefile              |   1 +
 drivers/mfd/upboard.c             | 273 ++++++++++++++++
 drivers/pinctrl/Kconfig           |  13 +
 drivers/pinctrl/Makefile          |   1 +
 drivers/pinctrl/pinctrl-upboard.c | 523 ++++++++++++++++++++++++++++++
 include/linux/mfd/upboard.h       |  70 ++++
 10 files changed, 996 insertions(+)
 create mode 100644 drivers/leds/leds-upboard.c
 create mode 100644 drivers/mfd/upboard.c
 create mode 100644 drivers/pinctrl/pinctrl-upboard.c
 create mode 100644 include/linux/mfd/upboard.h

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2.17.0