linux_dsm_epyc7002/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
Shawn Lin fca0c33003 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>
2017-06-29 17:13:09 +02:00

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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
- "rockchip,rv1108-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RV1108
- "rockchip,rk3036-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK3036
- "rockchip,rk3328-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK3328
- "rockchip,rk3368-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK3368
- "rockchip,rk3399-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK3399
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.
* 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 {
compatible = "rockchip,rk3288-dw-mshc";
reg = <0x12200000 0x1000>;
interrupts = <0 75 0>;
#address-cells = <1>;
#size-cells = <0>;
};