On Mon, Jun 13, 2016 at 10:14:31AM +0300, Roger Quadros wrote: > On 12/06/16 14:36, Peter Chen wrote: > > On Fri, Jun 10, 2016 at 04:07:22PM +0300, Roger Quadros wrote: > >> > >> +/** > >> + * usb_otg_add_gadget_udc - adds a new gadget to the udc class driver list > >> + * @parent: the parent device to this udc. Usually the controller > >> + * driver's device. > > > > It seems it should be udc device > > Parent and udc->dev are not the same right? Sure, udc's parent is otg device. > > I guess i'll omit the second statement to avoid confusion. So. > > @parent: the parent device to this udc. Where you call below APIs? It seems to be a udc driver, right? So, when you try to get "otg-controller" from the node, this node should be udc. /** * usb_otg_add_gadget_udc - adds a new gadget to the udc class driver list * @parent: the parent device to this udc. Usually the controller * driver's device. * @gadget: the gadget to be added to the list * @otg_dev: the OTG controller device * * If otg_dev is NULL then device tree node is checked * for OTG controller via the otg-controller property. * Returns zero on success, negative errno otherwise. */ int usb_otg_add_gadget_udc(struct device *parent, struct usb_gadget *gadget, struct device *otg_dev) { if (!otg_dev) { gadget->otg_dev = of_usb_get_otg(parent->of_node); if (!gadget->otg_dev) return -ENODEV; } else { gadget->otg_dev = otg_dev; } return usb_add_gadget_udc_release(parent, gadget, NULL); } EXPORT_SYMBOL_GPL(usb_otg_add_gadget_udc); -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html