OpenCloudOS-Kernel/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt

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Rockchip EMMC PHY
-----------------------
Required properties:
- compatible: rockchip,rk3399-emmc-phy
- #phy-cells: must be 0
- reg: PHY register address offset and length in "general
register files"
Optional properties:
- clock-names: Should contain "emmcclk". Although this is listed as optional
(because most boards can get basic functionality without having
access to it), it is strongly suggested.
See ../clock/clock-bindings.txt for details.
- clocks: Should have a phandle to the card clock exported by the SDHCI driver.
- drive-impedance-ohm: Specifies the drive impedance in Ohm.
Possible values are 33, 40, 50, 66 and 100.
If not set, the default value of 50 will be applied.
Example:
grf: syscon@ff770000 {
compatible = "rockchip,rk3399-grf", "syscon", "simple-mfd";
#address-cells = <1>;
#size-cells = <1>;
...
emmcphy: phy@f780 {
compatible = "rockchip,rk3399-emmc-phy";
reg = <0xf780 0x20>;
clocks = <&sdhci>;
clock-names = "emmcclk";
drive-impedance-ohm = <50>;
#phy-cells = <0>;
};
};