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Commit 5742b0c9 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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[PATCH] USB dummy_hcd: Partial OTG emulation 



Partial OTG support for dummy_hcd, mostly as a framework for further work.
It emulates the new OTG flags in the host and peripheral frameworks, if
that option is configured.  But it's incomplete:

  - Resetting the peripheral needs to clear the OTG state bits;
    a second enumeration won't work correctly.

  - This stops modeling HNP right when roles should switch the first time.
    It should probably disconnect, then set the usb_bus.is_b_host and
    usb_gadget.is_a_peripheral flags; then it'd enumerate almost normally,
    except for the role reversal.  Roles could then switch a second time,
    back to "normal" (with those flags cleared).

  - SRP should be modeled as "resume from port-unpowered", which is
    a state that usbcore doesn't yet use.

HNP can be triggered by enabling the OTG whitelist and configuring a
gadget driver that's not in that list; or by configuring Gadget Zero
to identify itself as the HNP test device.

Sent-by: default avatarDavid Brownell <david-b@pacbell.net>
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 65111084

drivers/usb/gadget/dummy_hcd.c

+28 −2
Original line number Diff line number Diff line
@@ -601,8 +601,10 @@ static int dummy_wakeup (struct usb_gadget *_gadget) 
	struct dummy	*dum;



	dum = gadget_to_dummy (_gadget);

	if ((dum->devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) == 0

			|| !(dum->port_status & (1 << USB_PORT_FEAT_SUSPEND)))

	if (!(dum->port_status & (1 << USB_PORT_FEAT_SUSPEND))

			|| !(dum->devstatus &

				( (1 << USB_DEVICE_B_HNP_ENABLE)

				| (1 << USB_DEVICE_REMOTE_WAKEUP))))

		return -EINVAL;



	/* hub notices our request, issues downstream resume, etc */
@@ -713,6 +715,9 @@ usb_gadget_register_driver (struct usb_gadget_driver *driver) 
	dum->gadget.ops = &dummy_ops;

	dum->gadget.is_dualspeed = 1;



	/* maybe claim OTG support, though we won't complete HNP */

	dum->gadget.is_otg = (dummy_to_hcd(dum)->self.otg_port != 0);



	dum->devstatus = 0;

	dum->resuming = 0;
@@ -1215,6 +1220,16 @@ static void dummy_timer (unsigned long _dum) 
					switch (setup.wValue) {

					case USB_DEVICE_REMOTE_WAKEUP:

						break;

					case USB_DEVICE_B_HNP_ENABLE:

						dum->gadget.b_hnp_enable = 1;

						break;

					case USB_DEVICE_A_HNP_SUPPORT:

						dum->gadget.a_hnp_support = 1;

						break;

					case USB_DEVICE_A_ALT_HNP_SUPPORT:

						dum->gadget.a_alt_hnp_support

							= 1;

						break;

					default:

						value = -EOPNOTSUPP;

					}
@@ -1533,6 +1548,13 @@ static int dummy_hub_control ( 
					spin_unlock (&dum->lock);

					dum->driver->suspend (&dum->gadget);

					spin_lock (&dum->lock);

					/* HNP would happen here; for now we

					 * assume b_bus_req is always true.

					 */

					if (((1 << USB_DEVICE_B_HNP_ENABLE)

							& dum->devstatus) != 0)

						dev_dbg (dummy_dev(dum),

							"no HNP yet!\n");

				}

			}

			break;
@@ -1648,6 +1670,10 @@ static int dummy_start (struct usb_hcd *hcd) 
	hcd->power_budget = 8;

	hcd->state = HC_STATE_RUNNING;



#ifdef CONFIG_USB_OTG

	hcd->self.otg_port = 1;

#endif



	/* FIXME 'urbs' should be a per-device thing, maybe in usbcore */

	device_create_file (dummy_dev(dum), &dev_attr_urbs);

	return 0;