Hi,
(and sorry for the huge delay)
On Mon, Oct 04, 2010 at 12:18:53PM -0500, Alan Stern wrote:
> On Mon, 4 Oct 2010, Felipe Balbi wrote:
>
> > this class will be used to abstract away
> > several of the duplicated operations scatered
> > among the USB gadget controller drivers.
> >
> > Later, we can add an atomic notifer to tell
> > interested drivers about what's happening
> > with the controller. Notifications such as
> > suspend, resume, enumerated, etc will be
> > useful, at a minimum, for implementing
> > usb charger detection.
>
> Why is this implemented in terms of a udc class device? Why not just
> associate the attributes with the controller device itself? Is this
> for the uevents?
The idea is that I want a core device which will do the talking to the
underlying Hardware, instead of duplicating the code all over as it is
done today.
> > +/**
> > + * usb_add_udc - adds a new udc to the udc class driver list
> > + * @parent: the parent device to this udc. Usually the controller
> > + * driver's device.
> > + * @udc: the udc to be added to the list
> > + *
> > + * Returns zero on success, negative errno otherwise.
> > + */
> > +int usb_add_udc(struct device *parent, struct usb_udc *udc)
> > +{
> > + struct device *dev;
> > + unsigned long flags;
> > + int ret;
> > +
> > + if (!udc->gadget || !udc->gadget->ops ||
> > + !udc->gadget->ops->start) {
> > + dev_dbg(parent, "unitializaed gadget\n");
> > + return -EINVAL;
> > + }
> > +
> > + dev_vdbg(parent, "registering UDC\n");
> > +
> > + dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> > + if (!dev) {
> > + ret = -ENOMEM;
> > + goto err1;
> > + }
> > +
> > + spin_lock_irqsave(&udc_lock, flags);
> > +
> > + device_initialize(dev);
> > +
> > + dev->class = udc_class;
> > + dev->type = &udc_device_type;
> > + dev->parent = parent;
> > + dev->release = usb_udc_release;
> > + dev_set_drvdata(dev, udc);
> > + udc->dev = dev;
> > + udc->gadget->dev.parent = udc->dev;
> > + udc->gadget->dev.release = usb_udc_nop_release;
>
> This causes problems with dummy-hcd. It actually needs to do something
> when the gadget device is released.
>
> Why not embed the gadget and the device node directly in the usb_udc
> structure, instead of just putting pointers there?
I'll do that now. Thanks.
--
balbi
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