[PATCH 14/14] usb: udc-core: add judgement logic for usb_gadget_connect

Peter Chen
2013-03-18T06:52:42Z

On Fri, Mar 15, 2013 at 12:37:01PM +0200, Felipe Balbi wrote:
> Hi,
>
> On Fri, Mar 15, 2013 at 06:04:08PM +0800, Peter Chen wrote:
> > On Fri, Mar 15, 2013 at 09:51:29AM +0200, Felipe Balbi wrote:
> > >
> > > that's all wrong and needs to be fixed. UDC-core has to be the central
> > > point for all these details. We start with the easiest way (call connect
> > > unconditionally after gadget driver is loaded) and optimize it as we go
> > > (making sure that there is VBUS before connecting pullups); but we can't
> > > bypass UDC-core and call usb_gadget_connect() directly from UDC driver.
> >
> > I have an idea that let the gadget driver call usb_gadget_connect/disconnect,
> > and make a refcount for calling .pullup at usb_gadget_connect/disconnect.
> > Below is an initial idea for it, I think it can also cover both udc
> > and uvc case.
> >
> > drivers/usb/chipidea/udc.c | 6 ++----
> > drivers/usb/gadget/composite.c | 6 ++++++
> > include/linux/usb/gadget.h | 21 +++++++++++++++++++--
> > 3 files changed, 27 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> > index 81184b9..4b6b2d8 100644
> > --- a/drivers/usb/chipidea/udc.c
> > +++ b/drivers/usb/chipidea/udc.c
> > @@ -1386,17 +1386,15 @@ static int ci13xxx_vbus_session(struct usb_gadget *_gadget, int is_active)
> > pm_runtime_get_sync(&_gadget->dev);
> > hw_device_reset(ci, USBMODE_CM_DC);
> > hw_device_state(ci, ci->ep0out->qh.dma);
> > - ci13xxx_pullup(_gadget, true);
> > + ci->driver->connect(&ci->gadget);
> > dev_dbg(ci->dev, "Connected to host\n");
> > } else {
> > - if (ci->driver)
> > - ci->driver->disconnect(&ci->gadget);
> > + ci->driver->disconnect(&ci->gadget);
> > hw_device_state(ci, 0);
> > if (ci->platdata->notify_event)
> > ci->platdata->notify_event(ci,
> > CI13XXX_CONTROLLER_STOPPED_EVENT);
> > _gadget_stop_activity(&ci->gadget);
> > - ci13xxx_pullup(_gadget, false);
> > pm_runtime_put_sync(&_gadget->dev);
> > dev_dbg(ci->dev, "Disconnected from host\n");
> > }
> > diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> > index 7c821de..b7bf5ae 100644
> > --- a/drivers/usb/gadget/composite.c
> > +++ b/drivers/usb/gadget/composite.c
> > @@ -1479,6 +1479,11 @@ done:
> > return value;
> > }
> >
> > +void composite_connect(struct usb_gadget *gadget)
> > +{
> > + usb_gadget_connect(gadget);
> > +}
> > +
> > void composite_disconnect(struct usb_gadget *gadget)
> > {
> > struct usb_composite_dev *cdev = get_gadget_data(gadget);
> > @@ -1492,6 +1497,7 @@ void composite_disconnect(struct usb_gadget *gadget)
> > reset_config(cdev);
> > if (cdev->driver->disconnect)
> > cdev->driver->disconnect(cdev);
> > + usb_gadget_disconnect(gadget);
> > spin_unlock_irqrestore(&cdev->lock, flags);
> > }
> >
> > diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> > index 7e373a2..7f7e6bf 100644
> > --- a/include/linux/usb/gadget.h
> > +++ b/include/linux/usb/gadget.h
> > @@ -536,6 +536,7 @@ struct usb_gadget {
> > struct device dev;
> > unsigned out_epnum;
> > unsigned in_epnum;
> > + int connection;
> > };
> >
> > static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
> > @@ -722,9 +723,16 @@ static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
> > */
> > static inline int usb_gadget_connect(struct usb_gadget *gadget)
> > {
> > + int ret = 0;
> > if (!gadget->ops->pullup)
> > return -EOPNOTSUPP;
> > - return gadget->ops->pullup(gadget, 1);
> > +
> > + if (gadget->connection == 0)
> > + ret = gadget->ops->pullup(gadget, 1);
> > + if (!ret)
> > + gadget->connection ++;
> > +
> > + return ret;
> > }
> >
> > /**
> > @@ -744,9 +752,18 @@ static inline int usb_gadget_connect(struct usb_gadget *gadget)
> > */
> > static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
> > {
> > + int ret = 0;
> > +
> > if (!gadget->ops->pullup)
> > return -EOPNOTSUPP;
> > - return gadget->ops->pullup(gadget, 0);
> > +
> > + if (gadget->connection == 1)
> > + ret = gadget->ops->pullup(gadget, 0);
> > +
> > + if (!ret)
> > + gadget->connection --;
> > +
> > + return ret;
> > }
>
> this might be a good idea. But we already have something similar,
> although it's managed at composite device level. Maybe we need to move
> that to the gadget layer. Still, I don't want to let UDC drivers call
> usb_gadget_connect()/disconnect() directly.
>
> It's easy enough for udc-core to handle that.
>

Not so easy, how let udc-core know vbus interrupt?

And we need to consider the udc drivers which support or not
support vbus interrupt together.
--

Best Regards,
Peter Chen