Hi

On 11/4/2011 10:15 PM, Grant Likely wrote:

On Fri, Nov 4, 2011 at 4:25 AM, Pavan Kondeti [off-list ref] wrote:

quoted

Hi

I am working on adding USB device tree support for MSM platform.  One of
our chip set has 2 hsusb cores. The first core is configured as otg and
the other core is configured in host only mode (EHCI compliant). Are the
below device node names Okay? Please suggest.

hsusb0-otg: usb@0xa6000000 {
       compatible = "qcom,hsusb-otg";
       ---
};

hsusb0-device: usb@0xa6000000 {
       compatible = "qcom,hsusb-device";
       ---
};

hsusb0-host: usb@0xa6000000 {
       compatible = "qcom,hsusb-host", "usb-ehci";
       ---
};

hsusb1-host: usb@0xa6000000 {
       compatible = "qcom,hsusb-host", "usb-ehci";
       ---
};

/* super speed support

ssusb0-device: usb@0xa6000000 {
       compatible = "qcom,ssusb-device";
};

The host controller node names as "usb@<adddr>" as you have here is
exactly right.  The driver doesn't care and will only look at the
compatible list.  OTG controllers can also use "usb@" as the prefix.

Controllers that are only in device mode should probably be called
something like "usb-gadget@<addr>" or similar, because "usb@" is used
for host controllers.

In our case OTG, gadget and host controllers are part of a single core
i.e they all share the same register address space.

If I use usb@addr for OTG controller, then host and OTG device node
names becomes same. Is that okay? Can two devices have the same device
node name in device tree source file?

The label names (hsusb*-host, hsusb*-device) are completely irrelevant
since Linux never sees them.  Use whatever you want for the label
names.

Is it a good practice to give label names? I thought, it improves a bit
readability of device tree source file.

Also, the form of the node name is: "usb@a6000000" (without '0x' in
the address).

Thanks for the correction.

Thanks,
Pavan


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