dt-bindings: rockchip-dw-mshc: add optional rockchip, desired-num-phases

By default, dw_mmc-rockchip will execute tuning for each degree.
So we won't miss every point of the good sample windows. However,
probably the phases are linear inside the good sample window.
Actually we don't need to do tuning for each degree so that we could
save some time, for instance, probe the driver or resume from S3.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
index 18e33cbe7eec8419d67e32189f9211e3a418e5aa..49ed3ad2524a4e7d64661117be3225ef6718257a 100644 (file)
--- a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
+++ b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
@@ -32,6 +32,10 @@ Optional Properties:
   probing, low speeds or in case where all phases work at tuning time.
   If not specified 0 deg will be used.
 
+* rockchip,desired-num-phases: The desired number of times that the host
+  execute tuning when needed. If not specified, the host will do tuning
+  for 360 times, namely tuning for each degree.
+
 Example:
 
        rkdwmmc0@12200000 {