linux/Documentation/devicetree/bindings/phy/rcar-gen2-phy.txt
Simon Horman 7777cb8ba0 phy: rcar-gen2: add fallback binding
In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 2 and Gen 3. But beyond that its not clear what the
relationship between IP blocks might be. For example, I believe that
r8a7790 is older than r8a7791 but that doesn't imply that the latter is a
descendant of the former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme being adopted for
drivers for Renesas SoCs.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2016-04-29 14:40:07 +05:30

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* Renesas R-Car generation 2 USB PHY
This file provides information on what the device node for the R-Car generation
2 USB PHY contains.
Required properties:
- compatible: "renesas,usb-phy-r8a7790" if the device is a part of R8A7790 SoC.
"renesas,usb-phy-r8a7791" if the device is a part of R8A7791 SoC.
"renesas,usb-phy-r8a7794" if the device is a part of R8A7794 SoC.
"renesas,rcar-gen2-usb-phy" for a generic R-Car Gen2 compatible device.
When compatible with the generic version, nodes must list the
SoC-specific version corresponding to the platform first
followed by the generic version.
- reg: offset and length of the register block.
- #address-cells: number of address cells for the USB channel subnodes, must
be <1>.
- #size-cells: number of size cells for the USB channel subnodes, must be <0>.
- clocks: clock phandle and specifier pair.
- clock-names: string, clock input name, must be "usbhs".
The USB PHY device tree node should have the subnodes corresponding to the USB
channels. These subnodes must contain the following properties:
- reg: the USB controller selector; see the table below for the values.
- #phy-cells: see phy-bindings.txt in the same directory, must be <1>.
The phandle's argument in the PHY specifier is the USB controller selector for
the USB channel; see the selector meanings below:
+-----------+---------------+---------------+
|\ Selector | | |
+ --------- + 0 | 1 |
| Channel \| | |
+-----------+---------------+---------------+
| 0 | PCI EHCI/OHCI | HS-USB |
| 2 | PCI EHCI/OHCI | xHCI |
+-----------+---------------+---------------+
Example (Lager board):
usb-phy@e6590100 {
compatible = "renesas,usb-phy-r8a7790", "renesas,rcar-gen2-usb-phy";
reg = <0 0xe6590100 0 0x100>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&mstp7_clks R8A7790_CLK_HSUSB>;
clock-names = "usbhs";
usb-channel@0 {
reg = <0>;
#phy-cells = <1>;
};
usb-channel@2 {
reg = <2>;
#phy-cells = <1>;
};
};