On Wed, Apr 20, 2016 at 09:54:49AM +0300, Roger Quadros wrote: > On 18/04/16 05:09, Peter Chen wrote: > > On Fri, Apr 15, 2016 at 02:00:46PM +0300, Roger Quadros wrote: > >> On 15/04/16 12:25, Peter Chen wrote: > >>> On Tue, Apr 05, 2016 at 05:05:12PM +0300, Roger Quadros wrote: > >>>> + * usb_otg_register() - Register the OTG/dual-role device to OTG core > >>>> + * @dev: OTG/dual-role controller device. > >>>> + * @config: OTG configuration. > >>>> + * > >>>> + * Registers the OTG/dual-role controller device with the USB OTG core. > >>>> + * > >>>> + * Return: struct usb_otg * if success, ERR_PTR() if error. > >>>> + */ > >>>> +struct usb_otg *usb_otg_register(struct device *dev, > >>>> + struct usb_otg_config *config) > >>>> +{ > >>>> + struct usb_otg *otg; > >>>> + struct otg_wait_data *wait; > >>>> + int ret = 0; > >>>> + > >>>> + if (!dev || !config || !config->fsm_ops) > >>>> + return ERR_PTR(-EINVAL); > >>>> + > >>>> + /* already in list? */ > >>>> + mutex_lock(&otg_list_mutex); > >>>> + if (usb_otg_get_data(dev)) { > >>>> + dev_err(dev, "otg: %s: device already in otg list\n", > >>>> + __func__); > >>>> + ret = -EINVAL; > >>>> + goto unlock; > >>>> + } > >>>> + > >>>> + /* allocate and add to list */ > >>>> + otg = kzalloc(sizeof(*otg), GFP_KERNEL); > >>>> + if (!otg) { > >>>> + ret = -ENOMEM; > >>>> + goto unlock; > >>>> + } > >>>> + > >>>> + otg->dev = dev; > >>>> + otg->caps = config->otg_caps; > >>>> + > >>>> + if ((otg->caps->hnp_support || otg->caps->srp_support || > >>>> + otg->caps->adp_support) && !config->otg_work) > >>>> + dev_info(dev, "otg: limiting to dual-role\n"); > >>> > >>> What does above mean? Customized otg_work item may be dual-role, > >>> may be full otg. > >> > >> I'm checking for !config->otg_work so we're sure of using the > >> default dual-role only work function. > >> > > > > I see. But whether it is dual-role or fully otg should depend on > > otg->caps, the work item may be different according to design. > > Besides, your code seems to depend on one of the otg capabilities > > for dual-role. > > > Which capability? Id/vbus status? > if (otg->caps->hnp_support || otg->caps->srp_support || otg->caps->adp_support) it is fully otg; else it is dual role; Do you think so? -- 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