linux/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
Alexandru M Stan f8085bbada mmc: dw_mmc-rockchip: dt-binding: Add tuning related things
Add ciu_drive, ciu_sample clocks and default-sample-phase. This will later
be used by tuning code.

We do not touch ciu_drive (and by extension define default-drive-phase).
Drive phase is mostly used to define minimum hold times, while one could
write some code to determine what phase meets the minimum hold time
(ex 10 degrees) this will not work with the current clock phase framework
(which floors angles, so we'll get 0 deg, and there's no way to know what
resolution the floors happen at). We assume that the default drive angles
set by the hardware are good enough.

Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-10-26 16:00:11 +01:00

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* Rockchip specific extensions to the Synopsys Designware Mobile
Storage Host Controller
The Synopsys designware mobile storage host controller is used to interface
a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
differences between the core Synopsys dw mshc controller properties described
by synopsys-dw-mshc.txt and the properties used by the Rockchip specific
extensions to the Synopsys Designware Mobile Storage Host Controller.
Required Properties:
* compatible: should be
- "rockchip,rk2928-dw-mshc": for Rockchip RK2928 and following,
before RK3288
- "rockchip,rk3288-dw-mshc": for Rockchip RK3288
Optional Properties:
* clocks: from common clock binding: if ciu_drive and ciu_sample are
specified in clock-names, should contain handles to these clocks.
* clock-names: Apart from the clock-names described in synopsys-dw-mshc.txt
two more clocks "ciu-drive" and "ciu-sample" are supported. They are used
to control the clock phases, "ciu-sample" is required for tuning high-
speed modes.
* rockchip,default-sample-phase: The default phase to set ciu_sample at
probing, low speeds or in case where all phases work at tuning time.
If not specified 0 deg will be used.
Example:
rkdwmmc0@12200000 {
compatible = "rockchip,rk3288-dw-mshc";
reg = <0x12200000 0x1000>;
interrupts = <0 75 0>;
#address-cells = <1>;
#size-cells = <0>;
};