[PATCH v4 1/1] USB: core: let USB device know device node

[Peter Chen]

On Fri, Feb 5, 2016 at 12:36 AM, Alan Stern <stern at rowland.harvard.edu> wrote:
> On Thu, 4 Feb 2016, Peter Chen wrote:
>
>> On Mon, Jan 25, 2016 at 03:24:39PM +0800, Peter Chen wrote:
>> > Although most of USB devices are hot-plug's, there are still some devices
>> > are hard wired on the board, eg, for HSIC and SSIC interface USB devices.
>> > If these kinds of USB devices are multiple functions, and they can supply
>> > other interfaces like i2c, gpios for other devices, we may need to
>> > describe these at device tree.
>> >
>> > In this commit, it uses "reg" in dts as physical port number to match
>> > the phyiscal port number decided by USB core, if they are the same,
>> > then the device node is for the device we are creating for USB core.
>> >
>> > Signed-off-by: Peter Chen <peter.chen at freescale.com>
>> > ---
>> > Changes for v4:
>> > - The range of "reg" should be 1-31, changing device node address
>> >   style as in lower case hexadecimal with leading zeroes suppressed
>> >   [binding doc, usb-device.txt]
>> > - Improve the example at binding doc, it describes node from the top
>> >   (the controller)
>> > - Delete the struct of_node * within struct usb_device
>> > - Using usb_hcd_find_raw_port_number to get raw port number under root
>> >   hub port
>> >
>>
>> Hi Alan, Arnd, and others, would you please give Ack for it if you
>> are OK with this patch? I am not sure if Greg will queue it or not
>> if no one Acks it, thanks.
>
>
>> > @@ -508,11 +509,20 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
>> >     dev->connect_time = jiffies;
>> >     dev->active_duration = -jiffies;
>> >  #endif
>> > -   if (root_hub)   /* Root hub always ok [and always wired] */
>> > +   if (root_hub) { /* Root hub always ok [and always wired] */
>> >             dev->authorized = 1;
>> > -   else {
>> > +           dev->dev.of_node = bus->controller->of_node;
>> > +   } else {
>> >             dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
>> >             dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
>> > +
>> > +           if (dev->dev.parent->parent == bus->controller)
>> > +                   /* device under root hub's port */
>> > +                   port1 = usb_hcd_find_raw_port_number(usb_hcd,
>> > +                           port1);
>
> I would change the test to "if (!parent->parent)" and add {} around the
> body (since it's 3 lines long).  Also, although this doesn't really
> matter, you could consider putting the new code inside the previous big
> "if" statement instead of down here at the end of the function.
>

Sorry, Alan, I can understand using (!parent->parent) to stands for
the device connects to the root hub port, others I can't understand.

-- 
BR,
Peter Chen