[PATCH V4 0/2] Add OpenPiton board support

[Tianrui Wei]

This patch set is to add OpenPiton board support. Patches are split into
several parts:

- [PATCH 1/2] add OpenPiton support to mmc driver
- [PATCH 2/2] add support for OpenPiton board

Description

- for mmc driver, it's settings are automatically configured at hardware level.
  We only need to expose the memory mapped interface through U-Boot driver model
- For OpenPiton, as we need to embed the device tree blob into the bitstream,
  there is currently no itb support

Tests checks

- Able to boot Debian Linux from SD card on Digilent Genesys 2
- Checkpatch is performed, with some warnings ignored

Changelogs
- V2
  . fix styles and typos in [1/2] and [2/2]
  . add board documentation in [2/2]
- V3
  . fix styles in [1/2]
- V4
  . fix checkpatch warnings in [1/2] except MAINTAINERS

 arch/riscv/Kconfig                      |   4 +
 arch/riscv/dts/Makefile                 |   1 +
 arch/riscv/dts/openpiton-riscv64.dts    | 159 +++++
 board/openpiton/riscv/Kconfig           |  42 ++
 board/openpiton/riscv/MAINTAINERS       |   6 +
 board/openpiton/riscv/Makefile          |   5 +
 board/openpiton/riscv/openpiton-riscv.c |  41 ++
 configs/openpiton_riscv64_defconfig     | 132 ++++
 doc/board/index.rst                     |   1 +
 doc/board/openpiton/index.rst           |   9 +
 doc/board/openpiton/riscv64.rst         | 885 ++++++++++++++++++++++++
 drivers/mmc/Kconfig                     |   7 +
 drivers/mmc/Makefile                    |   1 +
 drivers/mmc/piton_mmc.c                 | 172 +++++
 include/configs/openpiton-riscv.h       |  58 ++
 15 files changed, 1523 insertions(+)
 create mode 100644 arch/riscv/dts/openpiton-riscv64.dts
 create mode 100644 board/openpiton/riscv/Kconfig
 create mode 100644 board/openpiton/riscv/MAINTAINERS
 create mode 100644 board/openpiton/riscv/Makefile
 create mode 100644 board/openpiton/riscv/openpiton-riscv.c
 create mode 100644 configs/openpiton_riscv64_defconfig
 create mode 100644 doc/board/openpiton/index.rst
 create mode 100644 doc/board/openpiton/riscv64.rst
 create mode 100644 drivers/mmc/piton_mmc.c
 create mode 100644 include/configs/openpiton-riscv.h
--
2.17.1