at91_udc.c

linux下面gadget设备驱动

	while (!list_empty(&ep->queue)) {
		req = list_entry(ep->queue.next, struct at91_request, queue);
		done(ep, req, status);
	}
}

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

static int at91_ep_enable(struct usb_ep *_ep,
				const struct usb_endpoint_descriptor *desc)
{
	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
	struct at91_udc	*dev = ep->udc;
	u16		maxpacket;
	u32		tmp;
	unsigned long	flags;

	if (!_ep || !ep
			|| !desc || ep->desc
			|| _ep->name == ep0name
			|| desc->bDescriptorType != USB_DT_ENDPOINT
			|| (maxpacket = le16_to_cpu(desc->wMaxPacketSize)) == 0
			|| maxpacket > ep->maxpacket) {
		DBG("bad ep or descriptor\n");
		return -EINVAL;
	}

	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
		DBG("bogus device state\n");
		return -ESHUTDOWN;
	}

	tmp = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
	switch (tmp) {
	case USB_ENDPOINT_XFER_CONTROL:
		DBG("only one control endpoint\n");
		return -EINVAL;
	case USB_ENDPOINT_XFER_INT:
		if (maxpacket > 64)
			goto bogus_max;
		break;
	case USB_ENDPOINT_XFER_BULK:
		switch (maxpacket) {
		case 8:
		case 16:
		case 32:
		case 64:
			goto ok;
		}
bogus_max:
		DBG("bogus maxpacket %d\n", maxpacket);
		return -EINVAL;
	case USB_ENDPOINT_XFER_ISOC:
		if (!ep->is_pingpong) {
			DBG("iso requires double buffering\n");
			return -EINVAL;
		}
		break;
	}

ok:
	local_irq_save(flags);

	/* initialize endpoint to match this descriptor */
	ep->is_in = (desc->bEndpointAddress & USB_DIR_IN) != 0;
	ep->is_iso = (tmp == USB_ENDPOINT_XFER_ISOC);
	ep->stopped = 0;
	if (ep->is_in)
		tmp |= 0x04;
	tmp <<= 8;
	tmp |= AT91_UDP_EPEDS;
	__raw_writel(tmp, ep->creg);

	ep->desc = desc;
	ep->ep.maxpacket = maxpacket;

	/*
	 * reset/init endpoint fifo.  NOTE:  leaves fifo_bank alone,
	 * since endpoint resets don't reset hw pingpong state.
	 */
	at91_udp_write(dev, AT91_UDP_RST_EP, ep->int_mask);
	at91_udp_write(dev, AT91_UDP_RST_EP, 0);

	local_irq_restore(flags);
	return 0;
}

static int at91_ep_disable (struct usb_ep * _ep)
{
	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
	struct at91_udc	*udc = ep->udc;
	unsigned long	flags;

	if (ep == &ep->udc->ep[0])
		return -EINVAL;

	local_irq_save(flags);

	nuke(ep, -ESHUTDOWN);

	/* restore the endpoint's pristine config */
	ep->desc = NULL;
	ep->ep.maxpacket = ep->maxpacket;

	/* reset fifos and endpoint */
	if (ep->udc->clocked) {
		at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
		at91_udp_write(udc, AT91_UDP_RST_EP, 0);
		__raw_writel(0, ep->creg);
	}

	local_irq_restore(flags);
	return 0;
}

/*
 * this is a PIO-only driver, so there's nothing
 * interesting for request or buffer allocation.
 */

static struct usb_request *
at91_ep_alloc_request(struct usb_ep *_ep, unsigned int gfp_flags)
{
	struct at91_request *req;

	req = kzalloc(sizeof (struct at91_request), gfp_flags);
	if (!req)
		return NULL;

	INIT_LIST_HEAD(&req->queue);
	return &req->req;
}

static void at91_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
	struct at91_request *req;

	req = container_of(_req, struct at91_request, req);
	BUG_ON(!list_empty(&req->queue));
	kfree(req);
}

static int at91_ep_queue(struct usb_ep *_ep,
			struct usb_request *_req, gfp_t gfp_flags)
{
	struct at91_request	*req;
	struct at91_ep		*ep;
	struct at91_udc		*dev;
	int			status;
	unsigned long		flags;

	req = container_of(_req, struct at91_request, req);
	ep = container_of(_ep, struct at91_ep, ep);

	if (!_req || !_req->complete
			|| !_req->buf || !list_empty(&req->queue)) {
		DBG("invalid request\n");
		return -EINVAL;
	}

	if (!_ep || (!ep->desc && ep->ep.name != ep0name)) {
		DBG("invalid ep\n");
		return -EINVAL;
	}

	dev = ep->udc;

	if (!dev || !dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
		DBG("invalid device\n");
		return -EINVAL;
	}

	_req->status = -EINPROGRESS;
	_req->actual = 0;

	local_irq_save(flags);

	/* try to kickstart any empty and idle queue */
	if (list_empty(&ep->queue) && !ep->stopped) {
		int	is_ep0;

		/*
		 * If this control request has a non-empty DATA stage, this
		 * will start that stage.  It works just like a non-control
		 * request (until the status stage starts, maybe early).
		 *
		 * If the data stage is empty, then this starts a successful
		 * IN/STATUS stage.  (Unsuccessful ones use set_halt.)
		 */
		is_ep0 = (ep->ep.name == ep0name);
		if (is_ep0) {
			u32	tmp;

			if (!dev->req_pending) {
				status = -EINVAL;
				goto done;
			}

			/*
			 * defer changing CONFG until after the gadget driver
			 * reconfigures the endpoints.
			 */
			if (dev->wait_for_config_ack) {
				tmp = at91_udp_read(dev, AT91_UDP_GLB_STAT);
				tmp ^= AT91_UDP_CONFG;
				VDBG("toggle config\n");
				at91_udp_write(dev, AT91_UDP_GLB_STAT, tmp);
			}
			if (req->req.length == 0) {
ep0_in_status:
				PACKET("ep0 in/status\n");
				status = 0;
				tmp = __raw_readl(ep->creg);
				tmp &= ~SET_FX;
				tmp |= CLR_FX | AT91_UDP_TXPKTRDY;
				__raw_writel(tmp, ep->creg);
				dev->req_pending = 0;
				goto done;
			}
		}

		if (ep->is_in)
			status = write_fifo(ep, req);
		else {
			status = read_fifo(ep, req);

			/* IN/STATUS stage is otherwise triggered by irq */
			if (status && is_ep0)
				goto ep0_in_status;
		}
	} else
		status = 0;

	if (req && !status) {
		list_add_tail (&req->queue, &ep->queue);
		at91_udp_write(dev, AT91_UDP_IER, ep->int_mask);
	}
done:
	local_irq_restore(flags);
	return (status < 0) ? status : 0;
}

static int at91_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
	struct at91_ep	*ep;
	struct at91_request	*req;

	ep = container_of(_ep, struct at91_ep, ep);
	if (!_ep || ep->ep.name == ep0name)
		return -EINVAL;

	/* make sure it's actually queued on this endpoint */
	list_for_each_entry (req, &ep->queue, queue) {
		if (&req->req == _req)
			break;
	}
	if (&req->req != _req)
		return -EINVAL;

	done(ep, req, -ECONNRESET);
	return 0;
}

static int at91_ep_set_halt(struct usb_ep *_ep, int value)
{
	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
	struct at91_udc	*udc = ep->udc;
	u32 __iomem	*creg;
	u32		csr;
	unsigned long	flags;
	int		status = 0;

	if (!_ep || ep->is_iso || !ep->udc->clocked)
		return -EINVAL;

	creg = ep->creg;
	local_irq_save(flags);

	csr = __raw_readl(creg);

	/*
	 * fail with still-busy IN endpoints, ensuring correct sequencing
	 * of data tx then stall.  note that the fifo rx bytecount isn't
	 * completely accurate as a tx bytecount.
	 */
	if (ep->is_in && (!list_empty(&ep->queue) || (csr >> 16) != 0))
		status = -EAGAIN;
	else {
		csr |= CLR_FX;
		csr &= ~SET_FX;
		if (value) {
			csr |= AT91_UDP_FORCESTALL;
			VDBG("halt %s\n", ep->ep.name);
		} else {
			at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
			at91_udp_write(udc, AT91_UDP_RST_EP, 0);
			csr &= ~AT91_UDP_FORCESTALL;
		}
		__raw_writel(csr, creg);
	}

	local_irq_restore(flags);
	return status;
}

static const struct usb_ep_ops at91_ep_ops = {
	.enable		= at91_ep_enable,
	.disable	= at91_ep_disable,
	.alloc_request	= at91_ep_alloc_request,
	.free_request	= at91_ep_free_request,
	.queue		= at91_ep_queue,
	.dequeue	= at91_ep_dequeue,
	.set_halt	= at91_ep_set_halt,
	// there's only imprecise fifo status reporting
};

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

static int at91_get_frame(struct usb_gadget *gadget)
{
	struct at91_udc *udc = to_udc(gadget);

	if (!to_udc(gadget)->clocked)
		return -EINVAL;
	return at91_udp_read(udc, AT91_UDP_FRM_NUM) & AT91_UDP_NUM;
}

static int at91_wakeup(struct usb_gadget *gadget)
{
	struct at91_udc	*udc = to_udc(gadget);
	u32		glbstate;
	int		status = -EINVAL;
	unsigned long	flags;

	DBG("%s\n", __FUNCTION__ );
	local_irq_save(flags);

	if (!udc->clocked || !udc->suspended)
		goto done;

	/* NOTE:  some "early versions" handle ESR differently ... */

	glbstate = at91_udp_read(udc, AT91_UDP_GLB_STAT);
	if (!(glbstate & AT91_UDP_ESR))
		goto done;
	glbstate |= AT91_UDP_ESR;
	at91_udp_write(udc, AT91_UDP_GLB_STAT, glbstate);

done:
	local_irq_restore(flags);
	return status;
}

/* reinit == restore inital software state */
static void udc_reinit(struct at91_udc *udc)
{
	u32 i;

	INIT_LIST_HEAD(&udc->gadget.ep_list);
	INIT_LIST_HEAD(&udc->gadget.ep0->ep_list);

	for (i = 0; i < NUM_ENDPOINTS; i++) {
		struct at91_ep *ep = &udc->ep[i];

		if (i != 0)
			list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
		ep->desc = NULL;
		ep->stopped = 0;
		ep->fifo_bank = 0;
		ep->ep.maxpacket = ep->maxpacket;
		ep->creg = (void __iomem *) udc->udp_baseaddr + AT91_UDP_CSR(i);
		// initialiser une queue par endpoint
		INIT_LIST_HEAD(&ep->queue);
	}
}

static void stop_activity(struct at91_udc *udc)
{
	struct usb_gadget_driver *driver = udc->driver;
	int i;

	if (udc->gadget.speed == USB_SPEED_UNKNOWN)
		driver = NULL;
	udc->gadget.speed = USB_SPEED_UNKNOWN;
	udc->suspended = 0;

	for (i = 0; i < NUM_ENDPOINTS; i++) {
		struct at91_ep *ep = &udc->ep[i];
		ep->stopped = 1;
		nuke(ep, -ESHUTDOWN);
	}
	if (driver)
		driver->disconnect(&udc->gadget);

	udc_reinit(udc);
}

static void clk_on(struct at91_udc *udc)
{
	if (udc->clocked)
		return;
	udc->clocked = 1;
	clk_enable(udc->iclk);
	clk_enable(udc->fclk);
}

static void clk_off(struct at91_udc *udc)
{
	if (!udc->clocked)
		return;
	udc->clocked = 0;
	udc->gadget.speed = USB_SPEED_UNKNOWN;
	clk_disable(udc->fclk);
	clk_disable(udc->iclk);
}

/*
 * activate/deactivate link with host; minimize power usage for
 * inactive links by cutting clocks and transceiver power.
 */
static void pullup(struct at91_udc *udc, int is_on)
{
	if (!udc->enabled || !udc->vbus)
		is_on = 0;
	DBG("%sactive\n", is_on ? "" : "in");

	if (is_on) {
		clk_on(udc);
		at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXRSM);
		at91_udp_write(udc, AT91_UDP_TXVC, 0);
		if (cpu_is_at91rm9200())
			at91_set_gpio_value(udc->board.pullup_pin, 1);
		else if (cpu_is_at91sam9260() || cpu_is_at91sam9263()) {
			u32	txvc = at91_udp_read(udc, AT91_UDP_TXVC);

			txvc |= AT91_UDP_TXVC_PUON;
			at91_udp_write(udc, AT91_UDP_TXVC, txvc);
		} else if (cpu_is_at91sam9261()) {
			u32	usbpucr;

			usbpucr = at91_sys_read(AT91_MATRIX_USBPUCR);
			usbpucr |= AT91_MATRIX_USBPUCR_PUON;
			at91_sys_write(AT91_MATRIX_USBPUCR, usbpucr);
		}
	} else {
		stop_activity(udc);
		at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
		at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
		if (cpu_is_at91rm9200())
			at91_set_gpio_value(udc->board.pullup_pin, 0);
		else if (cpu_is_at91sam9260() || cpu_is_at91sam9263()) {
			u32	txvc = at91_udp_read(udc, AT91_UDP_TXVC);

			txvc &= ~AT91_UDP_TXVC_PUON;
			at91_udp_write(udc, AT91_UDP_TXVC, txvc);
		} else if (cpu_is_at91sam9261()) {
			u32	usbpucr;

			usbpucr = at91_sys_read(AT91_MATRIX_USBPUCR);
			usbpucr &= ~AT91_MATRIX_USBPUCR_PUON;
			at91_sys_write(AT91_MATRIX_USBPUCR, usbpucr);