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/dma-mapping.h>
#include <linux/slab.h>

#include "musb_core.h"


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

#define is_buffer_mapped(req) (is_dma_capable() && \
					(req->map_state != UN_MAPPED))

/* Maps the buffer to dma  */

static inline void map_dma_buffer(struct musb_request *request,
			struct musb *musb, struct musb_ep *musb_ep)
{
	int compatible = true;
	struct dma_controller *dma = musb->dma_controller;

	request->map_state = UN_MAPPED;

	if (!is_dma_capable() || !musb_ep->dma)
		return;

	/* Check if DMA engine can handle this request.
	 * DMA code must reject the USB request explicitly.
	 * Default behaviour is to map the request.
	 */
	if (dma->is_compatible)
		compatible = dma->is_compatible(musb_ep->dma,
				musb_ep->packet_sz, request->request.buf,
				request->request.length);
	if (!compatible)
		return;

	if (request->request.dma == DMA_ADDR_INVALID) {
		dma_addr_t dma_addr;
		int ret;

		dma_addr = dma_map_single(
				musb->controller,
				request->request.buf,
				request->request.length,
				request->tx
					? DMA_TO_DEVICE
					: DMA_FROM_DEVICE);
		ret = dma_mapping_error(musb->controller, dma_addr);
		if (ret)
			return;

		request->request.dma = dma_addr;
		request->map_state = MUSB_MAPPED;
	} else {
		dma_sync_single_for_device(musb->controller,
			request->request.dma,
			request->request.length,
			request->tx
				? DMA_TO_DEVICE
				: DMA_FROM_DEVICE);
		request->map_state = PRE_MAPPED;
	}
}

/* Unmap the buffer from dma and maps it back to cpu */
static inline void unmap_dma_buffer(struct musb_request *request,
				struct musb *musb)
{
	struct musb_ep *musb_ep = request->ep;

	if (!is_buffer_mapped(request) || !musb_ep->dma)
		return;

	if (request->request.dma == DMA_ADDR_INVALID) {
		dev_vdbg(musb->controller,
				"not unmapping a never mapped buffer\n");
		return;
	}
	if (request->map_state == MUSB_MAPPED) {
		dma_unmap_single(musb->controller,
			request->request.dma,
			request->request.length,
			request->tx
				? DMA_TO_DEVICE
				: DMA_FROM_DEVICE);
		request->request.dma = DMA_ADDR_INVALID;
	} else { /* PRE_MAPPED */
		dma_sync_single_for_cpu(musb->controller,
			request->request.dma,
			request->request.length,
			request->tx
				? DMA_TO_DEVICE
				: DMA_FROM_DEVICE);
	}
	request->map_state = UN_MAPPED;
}

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

	ep->busy = 1;
	spin_unlock(&musb->lock);

	if (!dma_mapping_error(&musb->g.dev, request->dma))
		unmap_dma_buffer(req, musb);

	if (request->status == 0)
		dev_dbg(musb->controller, "%s done request %p,  %d/%d\n",
				ep->end_point.name, request,
				req->request.actual, req->request.length);
	else
		dev_dbg(musb->controller, "%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		*musb = ep->musb;
	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;