Dear, Rob.

On 02/25/2015 11:38 PM, Rob Herring wrote:

On Wed, Jan 28, 2015 at 8:41 PM, Alim Akhtar [off-list ref] wrote:

quoted

From: Seungwon Jeon <redacted>

Implements HS400 mode support for exynos host driver.
This also include some updates as new mode is added.

Signed-off-by: Seungwon Jeon <redacted>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
[Alim: addressed review comments]
---
 .../devicetree/bindings/mmc/exynos-dw-mshc.txt     |    7 +
 drivers/mmc/host/dw_mmc-exynos.c                   |  185 ++++++++++++++++----
 drivers/mmc/host/dw_mmc-exynos.h                   |   19 +-
 drivers/mmc/host/dw_mmc.c                          |   16 +-
 drivers/mmc/host/dw_mmc.h                          |    2 +
 5 files changed, 195 insertions(+), 34 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
index ee4fc05..aad9844 100644
--- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
+++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt

@@ -36,6 +36,8 @@ Required Properties:
   in transmit mode and CIU clock phase shift value in receive mode for double
   data rate mode operation. Refer notes below for the order of the cells and the
   valid values.
+* samsung,dw-mshc-hs400-timing: Specifies the value of CIU TX and RX clock phase
+  shift value for hs400 mode operation.

What are the units?

Do you means what is "sumsung,dw-mshci-hs400-timing" unit?
It's timing value for eMMC/SD/SDIO clock phase.(It's exynos specific value.)
Using timing value can shift the H/W clock phase.
If invalid timing value is set, eMMC/SD/SDIO can produce the CRC error.

Do you think it can't include into device-tree?
I want to know your thinking. let me know, plz.

Best Regards,
Jaehoon Chung

Rob