dt-bindings: usb: add the documentation for USB HCDs

A USB HCD may have several PHYs which need to be configured before the
the HCD starts working.
This adds the documentation for such a USB HCD as well as a reference to
the new "usb-hcd.txt" from all bindings that implement a USB HCD which
support one USB PHY per port.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Yixun Lan <yixun.lan@amlogic.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.con>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt

@@ -32,7 +32,7 @@ Required properties:
 	"mcu_ck": mcu_bus clock for register access,
 	"dma_ck": dma_bus clock for data transfer by DMA
 
- - phys : a list of phandle + phy specifier pairs
+ - phys : see usb-hcd.txt in the current directory
 
 Optional properties:
  - wakeup-source : enable USB remote wakeup;
@@ -52,6 +52,9 @@ Optional properties:
 	See: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
  - imod-interval-ns: default interrupt moderation interval is 5000ns
 
+additionally the properties from usb-hcd.txt (in the current directory) are
+supported.
+
 Example:
 usb30: usb@11270000 {
 	compatible = "mediatek,mt8173-xhci";

Documentation/devicetree/bindings/usb/mediatek,mtu3.txt

@@ -17,7 +17,7 @@ Required properties:
  - clock-names : must contain "sys_ck" for clock of controller,
 	the following clocks are optional:
 	"ref_ck", "mcu_ck" and "dam_ck";
- - phys : a list of phandle + phy specifier pairs
+ - phys : see usb-hcd.txt in the current directory
  - dr_mode : should be one of "host", "peripheral" or "otg",
 	refer to usb/generic.txt
 
@@ -53,6 +53,9 @@ Optional properties:
  - mediatek,u3p-dis-msk : mask to disable u3ports, bit0 for u3port0,
 	bit1 for u3port1, ... etc;
 
+additionally the properties from usb-hcd.txt (in the current directory) are
+supported.
+
 Sub-nodes:
 The xhci should be added as subnode to mtu3 as shown in the following example
 if host mode is enabled. The DT binding details of xhci can be found in:

Documentation/devicetree/bindings/usb/usb-ehci.txt

@@ -16,10 +16,12 @@ Optional properties:
  - has-transaction-translator : boolean, set this if EHCI have a Transaction
 				Translator built into the root hub.
  - clocks : a list of phandle + clock specifier pairs
- - phys : phandle + phy specifier pair
- - phy-names : "usb"
+ - phys : see usb-hcd.txt in the current directory
  - resets : phandle + reset specifier pair
 
+additionally the properties from usb-hcd.txt (in the current directory) are
+supported.
+
 Example (Sequoia 440EPx):
     ehci@e0000300 {
 	   compatible = "ibm,usb-ehci-440epx", "usb-ehci";

Documentation/devicetree/bindings/usb/usb-hcd.txt

@@ -0,0 +1,9 @@
+Generic USB HCD (Host Controller Device) Properties
+
+Optional properties:
+- phys: a list of all USB PHYs on this HCD
+
+Example:
+	&usb1 {
+		phys = <&usb2_phy1>, <&usb3_phy1>;
+	};

Documentation/devicetree/bindings/usb/usb-ohci.txt

@@ -13,10 +13,12 @@ Optional properties:
 - remote-wakeup-connected: remote wakeup is wired on the platform
 - num-ports : u32, to override the detected port count
 - clocks : a list of phandle + clock specifier pairs
-- phys : phandle + phy specifier pair
-- phy-names : "usb"
+- phys : see usb-hcd.txt in the current directory
 - resets : a list of phandle + reset specifier pairs
 
+additionally the properties from usb-hcd.txt (in the current directory) are
+supported.
+
 Example:
 
 	ohci0: usb@1c14400 {

Documentation/devicetree/bindings/usb/usb-uhci.txt

@@ -6,6 +6,9 @@ Required properties:
 - reg : Should contain 1 register ranges(address and length)
 - interrupts : UHCI controller interrupt
 
+additionally the properties from usb-hcd.txt (in the current directory) are
+supported.
+
 Example:
 
 	uhci@d8007b00 {

Documentation/devicetree/bindings/usb/usb-xhci.txt

@@ -32,6 +32,11 @@ Optional properties:
   - usb3-lpm-capable: determines if platform is USB3 LPM capable
   - quirk-broken-port-ped: set if the controller has broken port disable mechanism
   - imod-interval-ns: default interrupt moderation interval is 5000ns
+  - phys : see usb-hcd.txt in the current directory
+
+additionally the properties from usb-hcd.txt (in the current directory) are
+supported.
+
 
 Example:
 	usb@f0931000 {