[RFC PATCH v5 0/9] Add external dma support for Synopsys MSHC

[Shawn Lin <shawn.lin@rock-chips.com>]

Synopsys DesignWare mobile storage host controller supports three
types of transfer mode: pio, internal dma and external dma. However,
dw_mmc can only supports pio and internal dma now. Thus some platforms
using dw-mshc integrated with generic dma can't work in dma mode. So we
submit this patch to achieve it.

And the config option, CONFIG_MMC_DW_IDMAC, was added by Will Newton
(commit:f95f3850) for the first version of dw_mmc and never be touched since
then. At that time dt-bindings hadn't been introduced into dw_mmc yet means
we should select CONFIG_MMC_DW_IDMAC to enable internal dma mode at compile
time. Nowadays, device-tree helps us to support a variety of boards with one
kernel. That's why we need to remove it and decide the transfer mode by reading
dw_mmc's HCON reg at runtime.

This RFC patch needs lots of ACKs. I know it's hard, but it does need someone
to make the running.

Patch does the following things:
- remove CONFIG_MMC_DW_IDMAC config option
- add bindings for edmac used by synopsys-dw-mshc
  at runtime
- add edmac support for synopsys-dw-mshc

Patch v1~v4 is based on next of git://git.linaro.org/people/ulf.hansson/mmc
Patch v5 is rebased on dw-mmc-for-ulf-v4.2 of https://github.com/jh80chung/dw-mmc.git


Changes in v5:
- add the title of cover letter
- fix typo of comment
- add macro for reading HCON register
- add "Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>" for exynos_defconfig patch
- add "Acked-by: Vineet Gupta <vgupta@synopsys.com>" for axs10x_defconfig patch
- add "Acked-by: Govindraj Raja <govindraj.raja@imgtec.com>" and
  "Acked-by: Ralf Baechle <ralf@linux-mips.org>" for pistachio_defconfig patch
- add "Acked-by: Joachim Eastwood <manabian@gmail.com>" for lpc18xx_defconfig patch
- add "Acked-by: Wei Xu <xuwei5@hisilicon.com>" for hisi_defconfig patch
- rebase on "https://github.com/jh80chung/dw-mmc.git tags/dw-mmc-for-ulf-v4.2" for merging easily

Changes in v4:
- remove "host->trans_mode" and use "host->use_dma" to indicate
  transfer mode.
- remove all bt-bindings' changes since we don't need new properities.
- check transfer mode at runtime by reading HCON reg
- spilt defconfig changes for each sub-architecture
- fix the title of cover letter
- reuse some code for reducing code size

Changes in v3:
- choose transfer mode at runtime
- remove all CONFIG_MMC_DW_IDMAC config option
- add supports-idmac property for some platforms

Changes in v2:
- Fix typo of dev_info msg
- remove unused dmach from declaration of dw_mci_dma_slave

Shawn Lin (9):
  mmc: dw_mmc: Add external dma interface support
  Documentation: synopsys-dw-mshc: add bindings for idmac and edmac
  mips: pistachio_defconfig: remove CONFIG_MMC_DW_IDMAC
  arc: axs10x_defconfig: remove CONFIG_MMC_DW_IDMAC
  arm: exynos_defconfig: remove CONFIG_MMC_DW_IDMAC
  arm: hisi_defconfig: remove CONFIG_MMC_DW_IDMAC
  arm: lpc18xx_defconfig: remove CONFIG_MMC_DW_IDMAC
  arm: multi_v7_defconfig: remove CONFIG_MMC_DW_IDMAC
  arm: zx_defconfig: remove CONFIG_MMC_DW_IDMAC

 .../devicetree/bindings/mmc/synopsys-dw-mshc.txt   |  25 +++
 arch/arc/configs/axs101_defconfig                  |   1 -
 arch/arc/configs/axs103_defconfig                  |   1 -
 arch/arc/configs/axs103_smp_defconfig              |   1 -
 arch/arm/configs/exynos_defconfig                  |   1 -
 arch/arm/configs/hisi_defconfig                    |   1 -
 arch/arm/configs/lpc18xx_defconfig                 |   1 -
 arch/arm/configs/multi_v7_defconfig                |   1 -
 arch/arm/configs/zx_defconfig                      |   1 -
 arch/mips/configs/pistachio_defconfig              |   1 -
 drivers/mmc/host/Kconfig                           |  11 +-
 drivers/mmc/host/dw_mmc-pltfm.c                    |   2 +
 drivers/mmc/host/dw_mmc.c                          | 209 ++++++++++++++++++---
 drivers/mmc/host/dw_mmc.h                          |   5 +
 include/linux/mmc/dw_mmc.h                         |  27 ++-
 15 files changed, 235 insertions(+), 53 deletions(-)

-- 
2.3.7