On Mon, May 09, 2016 at 12:45:38PM +0300, Roger Quadros wrote:
> On 06/05/16 12:41, Peter Chen wrote:
> > On Mon, May 02, 2016 at 03:18:46PM +0300, Roger Quadros wrote:
> >> The OTG core will use struct otg_hcd_ops to interface
> >> with the HCD controller.
> >>
> >> The main purpose of this interface is to avoid directly
> >> calling HCD APIs from the OTG core as they
> >> wouldn't be defined in the built-in symbol table if
> >> CONFIG_USB is m.
> >>
> >> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> >> Acked-by: Peter Chen <peter.chen@xxxxxxx>
> >
> > Roger, after thinking more, I still think current dependency between
> > OTG, HCD and gadget are too complicated. Since the OTG can't work
> > if it is built as module, I suggest letting OTG depends on HCD &&
> > USB_GADGET, and it is a boolean, in that case, we don't need to
> > export any HCD and gadget ops, things will be much simpler.
> > What's your opinion?
>
> How will it work if HCD and USB_GADGET are modules and OTG is built-in?
>
The OTG will not be compiled at this situation, since it is boolean.
In fact, like I mentioned at above, OTG or USB function can't work if
it is built as module.
Peter
> cheers,
> -roger
>
> >
> > Peter
> >
> >> ---
> >> include/linux/usb/hcd.h | 24 ++++++++++++++++++++++++
> >> 1 file changed, 24 insertions(+)
> >>
> >> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
> >> index b98f831..861ccaa 100644
> >> --- a/include/linux/usb/hcd.h
> >> +++ b/include/linux/usb/hcd.h
> >> @@ -399,6 +399,30 @@ struct hc_driver {
> >>
> >> };
> >>
> >> +/**
> >> + * struct otg_hcd_ops - Interface between OTG core and HCD
> >> + *
> >> + * Provided by the HCD core to allow the OTG core to interface with the HCD
> >> + *
> >> + * @add: function to add the HCD
> >> + * @remove: function to remove the HCD
> >> + * @usb_bus_start_enum: function to immediately start bus enumeration
> >> + * @usb_control_msg: function to build and send of a control urb
> >> + * @usb_hub_find_child: function to get pointer to the child device
> >> + */
> >> +struct otg_hcd_ops {
> >> + int (*add)(struct usb_hcd *hcd,
> >> + unsigned int irqnum, unsigned long irqflags);
> >> + void (*remove)(struct usb_hcd *hcd);
> >> + int (*usb_bus_start_enum)(struct usb_bus *bus, unsigned int port_num);
> >> + int (*usb_control_msg)(struct usb_device *dev, unsigned int pipe,
> >> + __u8 request, __u8 requesttype, __u16 value,
> >> + __u16 index, void *data, __u16 size,
> >> + int timeout);
> >> + struct usb_device * (*usb_hub_find_child)(struct usb_device *hdev,
> >> + int port1);
> >> +};
> >> +
> >> static inline int hcd_giveback_urb_in_bh(struct usb_hcd *hcd)
> >> {
> >> return hcd->driver->flags & HCD_BH;
> >> --
> >> 2.7.4
> >>
> >> --
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> >
--
Best Regards,
Peter Chen
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