musb_gadget.c

/*
 * MUSB OTG driver peripheral support
 *
 * Copyright 2005 Mentor Graphics Corporation
 * Copyright (C) 2005-2006 by Texas Instruments
 * Copyright (C) 2006-2007 Nokia Corporation
 * Copyright (C) 2009 MontaVista Software, Inc. <source@mvista.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/moduleparam.h>
#include <linux/stat.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>

#include "musb_core.h"


/* MUSB PERIPHERAL status 3-mar-2006:
 *
 * - EP0 seems solid.  It passes both USBCV and usbtest control cases.
 *   Minor glitches:
 *
 *     + remote wakeup to Linux hosts work, but saw USBCV failures;
 *       in one test run (operator error?)
 *     + endpoint halt tests -- in both usbtest and usbcv -- seem
 *       to break when dma is enabled ... is something wrongly
 *       clearing SENDSTALL?
 *
 * - Mass storage behaved ok when last tested.  Network traffic patterns
 *   (with lots of short transfers etc) need retesting; they turn up the
 *   worst cases of the DMA, since short packets are typical but are not
 *   required.
 *
 * - TX/IN
 *     + both pio and dma behave in with network and g_zero tests
 *     + no cppi throughput issues other than no-hw-queueing
 *     + failed with FLAT_REG (DaVinci)
 *     + seems to behave with double buffering, PIO -and- CPPI
 *     + with gadgetfs + AIO, requests got lost?
 *
 * - RX/OUT
 *     + both pio and dma behave in with network and g_zero tests
 *     + dma is slow in typical case (short_not_ok is clear)
 *     + double buffering ok with PIO
 *     + double buffering *FAILS* with CPPI, wrong data bytes sometimes
 *     + request lossage observed with gadgetfs
 *
 * - ISO not tested ... might work, but only weakly isochronous
 *
 * - Gadget driver disabling of softconnect during bind() is ignored; so
 *   drivers can't hold off host requests until userspace is ready.
 *   (Workaround:  they can turn it off later.)
 *
 * - PORTABILITY (assumes PIO works):
 *     + DaVinci, basically works with cppi dma
 *     + OMAP 2430, ditto with mentor dma
 *     + TUSB 6010, platform-specific dma in the works
 */

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

/*
 * Immediately complete a request.
 *
 * @param request the request to complete
 * @param status the status to complete the request with
 * Context: controller locked, IRQs blocked.
 */
void musb_g_giveback(
	struct musb_ep		*ep,
	struct usb_request	*request,
	int			status)
__releases(ep->musb->lock)
__acquires(ep->musb->lock)
{
	struct musb_request	*req;
	struct musb		*musb;
	int			busy = ep->busy;

	req = to_musb_request(request);

	list_del(&request->list);
	if (req->request.status == -EINPROGRESS)
		req->request.status = status;
	musb = req->musb;

	ep->busy = 1;
	spin_unlock(&musb->lock);
	if (is_dma_capable()) {
		if (req->mapped) {
			dma_unmap_single(musb->controller,
					req->request.dma,
					req->request.length,
					req->tx
						? DMA_TO_DEVICE
						: DMA_FROM_DEVICE);
			req->request.dma = DMA_ADDR_INVALID;
			req->mapped = 0;
		} else if (req->request.dma != DMA_ADDR_INVALID)
			dma_sync_single_for_cpu(musb->controller,
					req->request.dma,
					req->request.length,
					req->tx
						? DMA_TO_DEVICE
						: DMA_FROM_DEVICE);
	}
	if (request->status == 0)
		DBG(5, "%s done request %p,  %d/%d\n",
				ep->end_point.name, request,
				req->request.actual, req->request.length);
	else
		DBG(2, "%s request %p, %d/%d fault %d\n",
				ep->end_point.name, request,
				req->request.actual, req->request.length,
				request->status);
	req->request.complete(&req->ep->end_point, &req->request);
	spin_lock(&musb->lock);
	ep->busy = busy;
}

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

/*
 * Abort requests queued to an endpoint using the status. Synchronous.
 * caller locked controller and blocked irqs, and selected this ep.
 */
static void nuke(struct musb_ep *ep, const int status)
{
	struct musb_request	*req = NULL;
	void __iomem *epio = ep->musb->endpoints[ep->current_epnum].regs;

	ep->busy = 1;

	if (is_dma_capable() && ep->dma) {
		struct dma_controller	*c = ep->musb->dma_controller;
		int value;

		if (ep->is_in) {
			/*
			 * The programming guide says that we must not clear
			 * the DMAMODE bit before DMAENAB, so we only
			 * clear it in the second write...
			 */
			musb_writew(epio, MUSB_TXCSR,
				    MUSB_TXCSR_DMAMODE | MUSB_TXCSR_FLUSHFIFO);
			musb_writew(epio, MUSB_TXCSR,
					0 | MUSB_TXCSR_FLUSHFIFO);
		} else {
			musb_writew(epio, MUSB_RXCSR,
					0 | MUSB_RXCSR_FLUSHFIFO);
			musb_writew(epio, MUSB_RXCSR,
					0 | MUSB_RXCSR_FLUSHFIFO);
		}

		value = c->channel_abort(ep->dma);
		DBG(value ? 1 : 6, "%s: abort DMA --> %d\n", ep->name, value);
		c->channel_release(ep->dma);
		ep->dma = NULL;
	}

	while (!list_empty(&(ep->req_list))) {
		req = container_of(ep->req_list.next, struct musb_request,
				request.list);
		musb_g_giveback(ep, &req->request, status);
	}
}