Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core

[Peter Chen <hzpeterchen@gmail.com>]

On Tue, Apr 26, 2016 at 02:07:56AM +0000, Jun Li wrote:
> > +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");
> 
> dev_err, this should be an error.

The condition may be wrong, but it is an information to show
that current OTG is dual-role.

Peter
> 
> > +
> > +	if (config->otg_work)	/* custom otg_work ? */
> > +		INIT_WORK(&otg->work, config->otg_work);
> > +	else
> > +		INIT_WORK(&otg->work, usb_otg_work);
> > +
> > +	otg->wq = create_singlethread_workqueue("usb_otg");
> > +	if (!otg->wq) {
> > +		dev_err(dev, "otg: %s: can't create workqueue\n",
> > +			__func__);
> > +		ret = -ENOMEM;
> > +		goto err_wq;
> > +	}
> > +
> > +	/* set otg ops */
> > +	otg->fsm.ops = config->fsm_ops;
> > +
> > +	mutex_init(&otg->fsm.lock);
> > +
> > +	list_add_tail(&otg->list, &otg_list);
> > +	mutex_unlock(&otg_list_mutex);
> > +
> > +	/* were we in wait list? */
> > +	mutex_lock(&wait_list_mutex);
> > +	wait = usb_otg_get_wait(dev);
> > +	mutex_unlock(&wait_list_mutex);
> > +	if (wait) {
> > +		/* register pending host/gadget and flush from list */
> > +		usb_otg_flush_wait(dev);
> > +	}
> > +
> > +	return otg;
> > +
> > +err_wq:
> > +	kfree(otg);
> > +unlock:
> > +	mutex_unlock(&otg_list_mutex);
> > +	return ERR_PTR(ret);
> > +}
> > +EXPORT_SYMBOL_GPL(usb_otg_register);
> > +
> 
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-- 
Best Regards,
Peter Chen