On Mon, 18 Aug 2014, Peter Chen wrote:
> We introduce the connect API at usb_gadget_driver, the udc driver
> uses it to tell gadget driver that it is ready to CONNECT, and the
> dp can be pulled up from now on.
>
> Meanwhile, we introduce an API usb_udc_ready_to_connect to encapsulate
> above operation.
>
> Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
> ---
> include/linux/usb/gadget.h | 29 ++++++++++++++++++++++++++++-
> 1 file changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index c3a6185..385af59 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -873,12 +873,39 @@ struct usb_gadget_driver {
> void (*disconnect)(struct usb_gadget *);
> void (*suspend)(struct usb_gadget *);
> void (*resume)(struct usb_gadget *);
> + int (*connect)(struct usb_gadget *, bool connect);
>
> /* FIXME support safe rmmod */
> struct device_driver driver;
> };
This looks strange. Why do you have the "bool connect" parameter?
There's already a disconnect callback.
Also, you forgot to update the kerneldoc.
> -
> +/**
> + * usb_udc_ready_to_connect - The udc is ready to connect (physical pullup dp)
> + * @driver: the gadget driver for this gadget
> + * @gadget: the udc device
> + * @connect: whether the udc is ready to connect or not
> + *
> + * The USB 2.0 spec 7.2.1 and 7.1.5 requires the dp should not be pulled up if
> + * the vbus is not there, else it will fail Back-voltage Testing at below
> + * USB-IF certification test.
> + * www.usb.org/developers/docs/USB-IFTestProc1_3.pdf
> + *
> + * Some udcs have hardware logic that even the pullup bit is set by software,
> + * it can still meet above Back-voltage Testing requirement, these kinds of
> + * udcs only need to set connect as true at its .udc_start. But other udcs
> + * may have no this capability, so they need the software pullup bit is not
> + * set when the vbus is not there, otherwise it will break the spec, and can't
> + * pass Back-voltage Testing. So they need to set connect as false when the
> + * vbus is not there, and set connect as true when the vbus is there.
> + */
> +static inline int usb_udc_ready_to_connect(struct usb_gadget_driver *driver,
> + struct usb_gadget *gadget, bool connect)
> +{
> + if (driver->connect)
> + return driver->connect(gadget, connect);
> + else
> + return -EOPNOTSUPP;
> +}
>
> /*-------------------------------------------------------------------------*/
Again, the "connect" argument isn't needed.
Alan Stern
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