On Wed, Feb 27, 2019 at 03:23:10PM +0800, Stanley Chu wrote:
> Add UFS and UFS PHY node document for Mediatek SoC chips.
>
> Signed-off-by: Stanley Chu <[email protected]>
> ---
> .../devicetree/bindings/ufs/ufs-mediatek.txt | 47 +++++++++++++++++++
> 1 file changed, 47 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/ufs/ufs-mediatek.txt
>
> diff --git a/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt
> b/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt
> new file mode 100644
> index 000000000000..5fc985928b3e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt
> @@ -0,0 +1,47 @@
> +* Mediatek Universal Flash Storage (UFS) Host Controller
> +
> +UFS nodes are defined to describe on-chip UFS hardware macro.
> +Each UFS Host Controller should have its own node.
> +
> +To bind UFS PHY with UFS host controller, the controller node should
> +contain a phandle reference to UFS M-PHY node.
> +
> +Required properties for UFS nodes:
> +- compatible : Compatible list, contains the following controller:
> + "mediatek,ufshci"
Needs an SoC specific compatible string.
> +- reg : Address and length of the UFS register set.
> +- interrupt-parent : Interrupt device.
Drop this. It is implied or may be in a parent node.
> +- phys : phandle to m-phy.
> +- clocks : List of phandle and clock specifier pairs.
> +- clock-names : List of clock input name strings sorted in the same
> + order as the clocks property. "ufs-clk" is mandatory.
> +- freq-table-hz : Array of <min max> operating frequencies stored in
> the same
> + order as the clocks property. If this property is not
> + defined or a value in the array is "0" then it is
> assumed
> + that the frequency is set by the parent clock or a
> + fixed rate clock source.
> +- vcc-supply : Power to the UFS device.
> +- vcc-fixed-regulator: Specify that vcc-supply is a fixed regulator.
Why is this needed? The driver could query the voltage range of the
regulator or you could check the regulator node.
> +- lanes-per-direction: Number of lanes available per direction. Shall be 1.
If this can only be one value, then it can be implied by the compatible
string.
> +
> +Example:
> +
> + ufs_mphy: ufs_mphy@11fa0000 {
> + ...
> + };
> +
> + ufshci:ufshci@11270000 {
> + compatible = "mediatek,ufshci";
> + reg = <0 0x11270000 0 0x2300>;
> + interrupts = <GIC_SPI 104 IRQ_TYPE_LEVEL_LOW>;
> + phys = <&ufs_mphy>;
> +
> + clocks = <&infracfg_ao INFRACFG_AO_UFS_CG>;
> + clock-names = "ufs-clk";
> + freq-table-hz = <0 0>;
> +
> + vcc-supply = <&mt_pmic_vemc_ldo_reg>;
> + vcc-fixed-regulator;
> +
> + lanes-per-direction = <1>;
> + };
> --
> 2.18.0
>
