Hi Rob,
On Fri, Jan 13, 2017 at 9:08 PM, Rob Herring <robh@xxxxxxxxxx> wrote:
> On Wed, Jan 11, 2017 at 04:29:46PM +0100, Martin Blumenstingl wrote:
>> Many SoC platforms have separate devices for the USB PHY which are
>> registered through the generic PHY framework. These PHYs have to be
>> enabled to make the USB controller actually work. They also have to be
>> disabled again on shutdown/suspend.
>>
>> Currently (at least) the following HCI platform drivers are using custom
>> code to obtain all PHYs via devicetree for the roothub/controller and
>> disable/enable them when required:
>> - ehci-platform.c has ehci_platform_power_{on,off}
>> - xhci-mtk.c has xhci_mtk_phy_{init,exit,power_on,power_off}
>> - ohci-platform.c has ohci_platform_power_{on,off}
>>
>> These drivers are not using the generic devicetree USB device bindings
>> yet which were only introduced recently (documentation is available in
>> devicetree/bindings/usb/usb-device.txt).
>> With this new driver the usb2-phy and usb3-phy can be specified directly
>> in the child-node of the corresponding port of the roothub via
>> devicetree. This can be extended by not just parsing PHYs (some of the
>> other drivers listed above are for example also parsing a list of clocks
>> as well) when required.
>>
>> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
>> ---
>> .../devicetree/bindings/usb/usb-roothub.txt | 41 ++++++
>> drivers/usb/host/Kconfig | 3 +
>> drivers/usb/host/Makefile | 2 +
>> drivers/usb/host/platform-roothub.c | 146 +++++++++++++++++++++
>> drivers/usb/host/platform-roothub.h | 14 ++
>> 5 files changed, 206 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/usb/usb-roothub.txt
>> create mode 100644 drivers/usb/host/platform-roothub.c
>> create mode 100644 drivers/usb/host/platform-roothub.h
>>
>> diff --git a/Documentation/devicetree/bindings/usb/usb-roothub.txt b/Documentation/devicetree/bindings/usb/usb-roothub.txt
>> new file mode 100644
>> index 000000000000..96e152d3901c
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/usb/usb-roothub.txt
>> @@ -0,0 +1,41 @@
>> +Generic USB root-hub Properties
>> +
>> +similar to the USB device bindings (documented in usb-device.txt from the
>> +current directory) this provides support for configuring the root-hub.
>> +
>> +Required properties:
>> +- compatible: should be at least one of "usb1d6b,3", "usb1d6b,2"
>> +- reg: must be 0.
>> +- address-cells: must be 1
>> +- size-cells: must be 0
>
>> +- a sub-node per port supports the following properties:
>
> Make this another section with required and optional sections.
I can do that, but let's wait for the results if we want the PHYs to
be specified at the grand-child or child level
>> + - reg: the port number on the root-hub (mandatory)
>> + - phys: optional, from the *Generic PHY* bindings (mandatory needed when
>> + phy-names is given)
>> + - phy-names: optional, from the *Generic PHY* bindings; supported names
>> + are "usb2-phy" or "usb3-phy"
>> +
>> +Example:
>> + &usb1 {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + roothub@0 {
>> + compatible = "usb1d6b,3", "usb1d6b,2";
>
> Is this discoverable? IIRC, we had decided that ports on the root hub
> are just children of the USB controller node (rather than
> grandchildren). Why does that not work?
if I understand you correctly you are thinking of something like this:
&usb1 {
...cells...
port@1 {
reg = <1>;
phys = <&phy2>
}
port@2 {
reg = <2>;
phys = <&phy2>
}
}
in that case we need a way to differentiate between "actual device at
port 1" and "configuration for root-hub port 1".
in that example I also cannot specify a compatible string since I
don't know which device might be plugged into that port.
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> + reg = <0>;
>> +
>> + port@1 {
>
> Wouldn't this normally be 0 and 1. This should probably be usb-port
> rather than port to avoid OF graph overlap.
the USB subsystem starts counting at 1, there can never be a "device
with device-number 0" - so I think we should stay with 1 and 2 for a
2-port roothub.
I'm fine with changing the name to "usb-port" though
>> + reg = <1>;
>> + usb-phy = <&usb2_phy1>, <&usb3_phy1>;
>
> s/usb-phy/phys/
thanks for spotting this
>> + phy-names = "usb2-phy", "usb3-phy";
>> + };
>> +
>> + port@2 {
>> + reg = <2>;
>> + usb-phy = <&usb2_phy2>, <&usb3_phy2>;
>> + phy-names = "usb2-phy", "usb3-phy";
>> + };
>> + };
>> + }
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