[PATCH RFC 0/3] mmc: mxs-mmc: Implement DDR support

[Stefan Wahren <stefan.wahren@i2se.com>]

Based on these discussions: [1], [2] this patch series implements
DDR support for the MXS MMC host driver. This feature has never been
ported from the vendor kernel.

It has been tested on a i.MX28 board with eMMC which is currently
not in mainline (Duckbill 2).

* without DDR support
dd if=/dev/zero of=test bs=8k count=10000
81920000 bytes (82 MB) copied, 14.3321 s, 5.7 MB/s

* with DDR support:
dd if=/dev/zero of=test bs=8k count=10000
81920000 bytes (82 MB) copied, 13.4781 s, 6.1 MB/s

[1] - http://www.spinics.net/lists/linux-mmc/msg32285.html
[2] - http://www.spinics.net/lists/linux-mmc/msg34418.html

Stefan Wahren (3):
  DT: bindings: mmc: Add property for 3.3V only support
  mmc: core: add new cap for 3.3V only DDR MMCs
  mmc: mxs-mmc: Implement DDR support

 Documentation/devicetree/bindings/mmc/mmc.txt |    7 +++++--
 drivers/mmc/core/host.c                       |    2 ++
 drivers/mmc/core/mmc.c                        |    6 ++++++
 drivers/mmc/host/mxs-mmc.c                    |   22 ++++++++++++++++++++++
 include/linux/mmc/host.h                      |    1 +
 5 files changed, 36 insertions(+), 2 deletions(-)

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1.7.9.5