musb_gadget.c

	/* deactivate the hardware */
	if (musb->softconnect) {
		musb->softconnect = 0;
		musb_pullup(musb, 0);
	}
	musb_stop(musb);

	/* killing any outstanding requests will quiesce the driver;
	 * then report disconnect
	 */
	if (driver) {
		for (i = 0, hw_ep = musb->endpoints;
				i < musb->nr_endpoints;
				i++, hw_ep++) {
			musb_ep_select(musb->mregs, i);
			if (hw_ep->is_shared_fifo /* || !epnum */) {
				nuke(&hw_ep->ep_in, -ESHUTDOWN);
			} else {
				if (hw_ep->max_packet_sz_tx)
					nuke(&hw_ep->ep_in, -ESHUTDOWN);
				if (hw_ep->max_packet_sz_rx)
					nuke(&hw_ep->ep_out, -ESHUTDOWN);
			}
		}
	}
}

/*
 * Unregister the gadget driver. Used by gadget drivers when
 * unregistering themselves from the controller.
 *
 * @param driver the gadget driver to unregister
 */
static int musb_gadget_stop(struct usb_gadget *g,
		struct usb_gadget_driver *driver)
{
	struct musb	*musb = gadget_to_musb(g);
	unsigned long	flags;

	if (musb->xceiv->last_event == USB_EVENT_NONE)
		pm_runtime_get_sync(musb->controller);

	/*
	 * REVISIT always use otg_set_peripheral() here too;
	 * this needs to shut down the OTG engine.
	 */

	spin_lock_irqsave(&musb->lock, flags);

	musb_hnp_stop(musb);

	(void) musb_gadget_vbus_draw(&musb->g, 0);

	musb->xceiv->state = OTG_STATE_UNDEFINED;
	stop_activity(musb, driver);
	otg_set_peripheral(musb->xceiv->otg, NULL);

	dev_dbg(musb->controller, "unregistering driver %s\n", driver->function);

	musb->is_active = 0;
	musb_platform_try_idle(musb, 0);
	spin_unlock_irqrestore(&musb->lock, flags);

	usb_remove_hcd(musb_to_hcd(musb));
	/*
	 * FIXME we need to be able to register another
	 * gadget driver here and have everything work;
	 * that currently misbehaves.
	 */

	pm_runtime_put(musb->controller);

	return 0;
}

/* ----------------------------------------------------------------------- */

/* lifecycle operations called through plat_uds.c */

void musb_g_resume(struct musb *musb)
{
	musb->is_suspended = 0;
	switch (musb->xceiv->state) {
	case OTG_STATE_B_IDLE:
		break;
	case OTG_STATE_B_WAIT_ACON:
	case OTG_STATE_B_PERIPHERAL:
		musb->is_active = 1;
		if (musb->gadget_driver && musb->gadget_driver->resume) {
			spin_unlock(&musb->lock);
			musb->gadget_driver->resume(&musb->g);
			spin_lock(&musb->lock);
		}
		break;
	default:
		WARNING("unhandled RESUME transition (%s)\n",
				otg_state_string(musb->xceiv->state));
	}
}

/* called when SOF packets stop for 3+ msec */
void musb_g_suspend(struct musb *musb)
{
	u8	devctl;

	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
	dev_dbg(musb->controller, "devctl %02x\n", devctl);

	switch (musb->xceiv->state) {
	case OTG_STATE_B_IDLE:
		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
			musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
		break;
	case OTG_STATE_B_PERIPHERAL:
		musb->is_suspended = 1;
		if (musb->gadget_driver && musb->gadget_driver->suspend) {
			spin_unlock(&musb->lock);
			musb->gadget_driver->suspend(&musb->g);
			spin_lock(&musb->lock);
		}
		break;
	default:
		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
		 * A_PERIPHERAL may need care too
		 */
		WARNING("unhandled SUSPEND transition (%s)\n",
				otg_state_string(musb->xceiv->state));
	}
}

/* Called during SRP */
void musb_g_wakeup(struct musb *musb)
{
	musb_gadget_wakeup(&musb->g);
}

/* called when VBUS drops below session threshold, and in other cases */
void musb_g_disconnect(struct musb *musb)
{
	void __iomem	*mregs = musb->mregs;
	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);

	dev_dbg(musb->controller, "devctl %02x\n", devctl);

	/* clear HR */
	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);

	/* don't draw vbus until new b-default session */
	(void) musb_gadget_vbus_draw(&musb->g, 0);

	musb->g.speed = USB_SPEED_UNKNOWN;
	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
		spin_unlock(&musb->lock);
		musb->gadget_driver->disconnect(&musb->g);
		spin_lock(&musb->lock);
	}

	switch (musb->xceiv->state) {
	default:
		dev_dbg(musb->controller, "Unhandled disconnect %s, setting a_idle\n",
			otg_state_string(musb->xceiv->state));
		musb->xceiv->state = OTG_STATE_A_IDLE;
		MUSB_HST_MODE(musb);
		break;
	case OTG_STATE_A_PERIPHERAL:
		musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
		MUSB_HST_MODE(musb);
		break;
	case OTG_STATE_B_WAIT_ACON:
	case OTG_STATE_B_HOST:
	case OTG_STATE_B_PERIPHERAL:
	case OTG_STATE_B_IDLE:
		musb->xceiv->state = OTG_STATE_B_IDLE;
		break;
	case OTG_STATE_B_SRP_INIT:
		break;
	}

	musb->is_active = 0;
}

void musb_g_reset(struct musb *musb)
__releases(musb->lock)
__acquires(musb->lock)
{
	void __iomem	*mbase = musb->mregs;
	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
	u8		power;

	dev_dbg(musb->controller, "<== %s driver '%s'\n",
			(devctl & MUSB_DEVCTL_BDEVICE)
				? "B-Device" : "A-Device",
			musb->gadget_driver
				? musb->gadget_driver->driver.name
				: NULL
			);

	/* report disconnect, if we didn't already (flushing EP state) */
	if (musb->g.speed != USB_SPEED_UNKNOWN)
		musb_g_disconnect(musb);

	/* clear HR */
	else if (devctl & MUSB_DEVCTL_HR)
		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);


	/* what speed did we negotiate? */
	power = musb_readb(mbase, MUSB_POWER);
	musb->g.speed = (power & MUSB_POWER_HSMODE)
			? USB_SPEED_HIGH : USB_SPEED_FULL;

	/* start in USB_STATE_DEFAULT */
	musb->is_active = 1;
	musb->is_suspended = 0;
	MUSB_DEV_MODE(musb);
	musb->address = 0;
	musb->ep0_state = MUSB_EP0_STAGE_SETUP;

	musb->may_wakeup = 0;
	musb->g.b_hnp_enable = 0;
	musb->g.a_alt_hnp_support = 0;
	musb->g.a_hnp_support = 0;

	/* Normal reset, as B-Device;
	 * or else after HNP, as A-Device
	 */
	if (devctl & MUSB_DEVCTL_BDEVICE) {
		musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
		musb->g.is_a_peripheral = 0;
	} else {
		musb->xceiv->state = OTG_STATE_A_PERIPHERAL;
		musb->g.is_a_peripheral = 1;
	}

	/* start with default limits on VBUS power draw */
	(void) musb_gadget_vbus_draw(&musb->g, 8);
}