net2280.c

ARM S3C2410 USB SLAVE LINUX驱动

		if (ep->dma)
			start_dma (ep, req);
		else {
			/* maybe there's no control data, just status ack */
			if (ep->num == 0 && _req->length == 0) {
				allow_status (ep);
				done (ep, req, 0);
				VDEBUG (dev, "%s status ack\n", ep->ep.name);
				goto done;
			}

			/* PIO ... stuff the fifo, or unblock it.  */
			if (ep->is_in)
				write_fifo (ep, _req);
			else if (list_empty (&ep->queue)) {
				u32	s;

				/* OUT FIFO might have packet(s) buffered */
				s = readl (&ep->regs->ep_stat);
				if ((s & (1 << FIFO_EMPTY)) == 0) {
					/* note:  _req->short_not_ok is
					 * ignored here since PIO _always_
					 * stops queue advance here, and
					 * _req->status doesn't change for
					 * short reads (only _req->actual)
					 */
					if (read_fifo (ep, req)) {
						done (ep, req, 0);
						if (ep->num == 0)
							allow_status (ep);
						/* don't queue it */
						req = NULL;
					} else
						s = readl (&ep->regs->ep_stat);
				}

				/* don't NAK, let the fifo fill */
				if (req && (s & (1 << NAK_OUT_PACKETS)))
					writel ((1 << CLEAR_NAK_OUT_PACKETS),
							&ep->regs->ep_rsp);
			}
		}

	} else if (ep->dma) {
		int	valid = 1;

		if (ep->is_in) {
			int	expect;

			/* preventing magic zlps is per-engine state, not
			 * per-transfer; irq logic must recover hiccups.
			 */
			expect = likely (req->req.zero
				|| (req->req.length % ep->ep.maxpacket) != 0);
			if (expect != ep->in_fifo_validate)
				valid = 0;
		}
		queue_dma (ep, req, valid);

	} /* else the irq handler advances the queue. */

	if (req)
		list_add_tail (&req->queue, &ep->queue);
done:
	spin_unlock_irqrestore (&dev->lock, flags);

	/* pci writes may still be posted */
	return 0;
}

static inline void
dma_done (
	struct net2280_ep *ep,
	struct net2280_request *req,
	u32 dmacount,
	int status
)
{
	req->req.actual = req->req.length - (DMA_BYTE_COUNT_MASK & dmacount);
	done (ep, req, status);
}

static void restart_dma (struct net2280_ep *ep);

static void scan_dma_completions (struct net2280_ep *ep)
{
	/* only look at descriptors that were "naturally" retired,
	 * so fifo and list head state won't matter
	 */
	while (!list_empty (&ep->queue)) {
		struct net2280_request	*req;
		u32			tmp;

		req = list_entry (ep->queue.next,
				struct net2280_request, queue);
		if (!req->valid)
			break;
		rmb ();
		tmp = le32_to_cpup (&req->td->dmacount);
		if ((tmp & (1 << VALID_BIT)) != 0)
			break;

		/* SHORT_PACKET_TRANSFERRED_INTERRUPT handles "usb-short"
		 * cases where DMA must be aborted; this code handles
		 * all non-abort DMA completions.
		 */
		if (unlikely (req->td->dmadesc == 0)) {
			/* paranoia */
			tmp = readl (&ep->dma->dmacount);
			if (tmp & DMA_BYTE_COUNT_MASK)
				break;
			/* single transfer mode */
			dma_done (ep, req, tmp, 0);
			break;
		} else if (!ep->is_in
				&& (req->req.length % ep->ep.maxpacket) != 0) {
			tmp = readl (&ep->regs->ep_stat);

			/* AVOID TROUBLE HERE by not issuing short reads from
			 * your gadget driver.  That helps avoids errata 0121,
			 * 0122, and 0124; not all cases trigger the warning.
			 */
			if ((tmp & (1 << NAK_OUT_PACKETS)) == 0) {
				WARN (ep->dev, "%s lost packet sync!\n",
						ep->ep.name);
				req->req.status = -EOVERFLOW;
			} else if ((tmp = readl (&ep->regs->ep_avail)) != 0) {
				/* fifo gets flushed later */
				ep->out_overflow = 1;
				DEBUG (ep->dev, "%s dma, discard %d len %d\n",
						ep->ep.name, tmp,
						req->req.length);
				req->req.status = -EOVERFLOW;
			}
		}
		dma_done (ep, req, tmp, 0);
	}
}

static void restart_dma (struct net2280_ep *ep)
{
	struct net2280_request	*req;
	u32			dmactl = dmactl_default;

	if (ep->stopped)
		return;
	req = list_entry (ep->queue.next, struct net2280_request, queue);

	if (!use_dma_chaining) {
		start_dma (ep, req);
		return;
	}

	/* the 2280 will be processing the queue unless queue hiccups after
	 * the previous transfer:
	 *  IN:   wanted automagic zlp, head doesn't (or vice versa)
	 *        DMA_FIFO_VALIDATE doesn't init from dma descriptors.
	 *  OUT:  was "usb-short", we must restart.
	 */
	if (ep->is_in && !req->valid) {
		struct net2280_request	*entry, *prev = NULL;
		int			reqmode, done = 0;

		DEBUG (ep->dev, "%s dma hiccup td %p\n", ep->ep.name, req->td);
		ep->in_fifo_validate = likely (req->req.zero
			|| (req->req.length % ep->ep.maxpacket) != 0);
		if (ep->in_fifo_validate)
			dmactl |= (1 << DMA_FIFO_VALIDATE);
		list_for_each_entry (entry, &ep->queue, queue) {
			__le32		dmacount;

			if (entry == req)
				continue;
			dmacount = entry->td->dmacount;
			if (!done) {
				reqmode = likely (entry->req.zero
					|| (entry->req.length
						% ep->ep.maxpacket) != 0);
				if (reqmode == ep->in_fifo_validate) {
					entry->valid = 1;
					dmacount |= valid_bit;
					entry->td->dmacount = dmacount;
					prev = entry;
					continue;
				} else {
					/* force a hiccup */
					prev->td->dmacount |= dma_done_ie;
					done = 1;
				}
			}

			/* walk the rest of the queue so unlinks behave */
			entry->valid = 0;
			dmacount &= ~valid_bit;
			entry->td->dmacount = dmacount;
			prev = entry;
		}
	}

	writel (0, &ep->dma->dmactl);
	start_queue (ep, dmactl, req->td_dma);
}

static void abort_dma (struct net2280_ep *ep)
{
	/* abort the current transfer */
	if (likely (!list_empty (&ep->queue))) {
		/* FIXME work around errata 0121, 0122, 0124 */
		writel ((1 << DMA_ABORT), &ep->dma->dmastat);
		spin_stop_dma (ep->dma);
	} else
		stop_dma (ep->dma);
	scan_dma_completions (ep);
}

/* dequeue ALL requests */
static void nuke (struct net2280_ep *ep)
{
	struct net2280_request	*req;

	/* called with spinlock held */
	ep->stopped = 1;
	if (ep->dma)
		abort_dma (ep);
	while (!list_empty (&ep->queue)) {
		req = list_entry (ep->queue.next,
				struct net2280_request,
				queue);
		done (ep, req, -ESHUTDOWN);
	}
}

/* dequeue JUST ONE request */
static int net2280_dequeue (struct usb_ep *_ep, struct usb_request *_req)
{
	struct net2280_ep	*ep;
	struct net2280_request	*req;
	unsigned long		flags;
	u32			dmactl;
	int			stopped;

	ep = container_of (_ep, struct net2280_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0) || !_req)
		return -EINVAL;

	spin_lock_irqsave (&ep->dev->lock, flags);
	stopped = ep->stopped;

	/* quiesce dma while we patch the queue */
	dmactl = 0;
	ep->stopped = 1;
	if (ep->dma) {
		dmactl = readl (&ep->dma->dmactl);
		/* WARNING erratum 0127 may kick in ... */
		stop_dma (ep->dma);
		scan_dma_completions (ep);
	}

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

	/* queue head may be partially complete. */
	if (ep->queue.next == &req->queue) {
		if (ep->dma) {
			DEBUG (ep->dev, "unlink (%s) dma\n", _ep->name);
			_req->status = -ECONNRESET;
			abort_dma (ep);
			if (likely (ep->queue.next == &req->queue)) {
				// NOTE: misreports single-transfer mode
				req->td->dmacount = 0;	/* invalidate */
				dma_done (ep, req,
					readl (&ep->dma->dmacount),
					-ECONNRESET);
			}
		} else {
			DEBUG (ep->dev, "unlink (%s) pio\n", _ep->name);
			done (ep, req, -ECONNRESET);
		}
		req = NULL;

	/* patch up hardware chaining data */
	} else if (ep->dma && use_dma_chaining) {
		if (req->queue.prev == ep->queue.next) {
			writel (le32_to_cpu (req->td->dmadesc),
				&ep->dma->dmadesc);
			if (req->td->dmacount & dma_done_ie)
				writel (readl (&ep->dma->dmacount)
						| le32_to_cpu(dma_done_ie),
					&ep->dma->dmacount);
		} else {
			struct net2280_request	*prev;

			prev = list_entry (req->queue.prev,
				struct net2280_request, queue);
			prev->td->dmadesc = req->td->dmadesc;
			if (req->td->dmacount & dma_done_ie)
				prev->td->dmacount |= dma_done_ie;
		}
	}

	if (req)
		done (ep, req, -ECONNRESET);
	ep->stopped = stopped;

	if (ep->dma) {
		/* turn off dma on inactive queues */
		if (list_empty (&ep->queue))
			stop_dma (ep->dma);
		else if (!ep->stopped) {
			/* resume current request, or start new one */
			if (req)
				writel (dmactl, &ep->dma->dmactl);
			else
				start_dma (ep, list_entry (ep->queue.next,
					struct net2280_request, queue));
		}
	}

	spin_unlock_irqrestore (&ep->dev->lock, flags);
	return 0;
}

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

static int net2280_fifo_status (struct usb_ep *_ep);

static int
net2280_set_halt (struct usb_ep *_ep, int value)
{
	struct net2280_ep	*ep;
	unsigned long		flags;
	int			retval = 0;

	ep = container_of (_ep, struct net2280_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0))
		return -EINVAL;
	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;
	if (ep->desc /* not ep0 */ && (ep->desc->bmAttributes & 0x03)
						== USB_ENDPOINT_XFER_ISOC)
		return -EINVAL;

	spin_lock_irqsave (&ep->dev->lock, flags);
	if (!list_empty (&ep->queue))
		retval = -EAGAIN;
	else if (ep->is_in && value && net2280_fifo_status (_ep) != 0)
		retval = -EAGAIN;
	else {
		VDEBUG (ep->dev, "%s %s halt\n", _ep->name,
				value ? "set" : "clear");
		/* set/clear, then synch memory views with the device */
		if (value) {
			if (ep->num == 0)
				ep->dev->protocol_stall = 1;
			else
				set_halt (ep);
		} else
			clear_halt (ep);
		(void) readl (&ep->regs->ep_rsp);
	}
	spin_unlock_irqrestore (&ep->dev->lock, flags);

	return retval;
}

static int
net2280_fifo_status (struct usb_ep *_ep)
{
	struct net2280_ep	*ep;
	u32			avail;

	ep = container_of (_ep, struct net2280_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0))
		return -ENODEV;
	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;

	avail = readl (&ep->regs->ep_avail) & ((1 << 12) - 1);
	if (avail > ep->fifo_size)
		return -EOVERFLOW;
	if (ep->is_in)
		avail = ep->fifo_size - avail;
	return avail;
}

static void
net2280_fifo_flush (struct usb_ep *_ep)
{
	struct net2280_ep	*ep;

	ep = container_of (_ep, struct net2280_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0))
		return;
	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
		return;

	writel ((1 << FIFO_FLUSH), &ep->regs->ep_stat);
	(void) readl (&ep->regs->ep_rsp);
}

static struct usb_ep_ops net2280_ep_ops = {
	.enable		= net2280_enable,
	.disable	= net2280_disable,

	.alloc_request	= net2280_alloc_request,
	.free_request	= net2280_free_request,

	.alloc_buffer	= net2280_alloc_buffer,
	.free_buffer	= net2280_free_buffer,

	.queue		= net2280_queue,
	.dequeue	= net2280_dequeue,

	.set_halt	= net2280_set_halt,
	.fifo_status	= net2280_fifo_status,
	.fifo_flush	= net2280_fifo_flush,
};

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

static int net2280_get_frame (struct usb_gadget *_gadget)
{
	struct net2280		*dev;
	unsigned long		flags;
	u16			retval;

	if (!_gadget)
		return -ENODEV;
	dev = container_of (_gadget, struct net2280, gadget);
	spin_lock_irqsave (&dev->lock, flags);
	retval = get_idx_reg (dev->regs, REG_FRAME) & 0x03ff;
	spin_unlock_irqrestore (&dev->lock, flags);
	return retval;
}

static int net2280_wakeup (struct usb_gadget *_gadget)
{
	struct net2280		*dev;
	u32			tmp;
	unsigned long		flags;

	if (!_gadget)
		return 0;
	dev = container_of (_gadget, struct net2280, gadget);

	spin_lock_irqsave (&dev->lock, flags);
	tmp = readl (&dev->usb->usbctl);
	if (tmp & (1 << DEVICE_REMOTE_WAKEUP_ENABLE))
		writel (1 << GENERATE_RESUME, &dev->usb->usbstat);
	spin_unlock_irqrestore (&dev->lock, flags);

	/* pci writes may still be posted */
	return 0;
}

static int net2280_set_selfpowered (struct usb_gadget *_gadget, int value)
{
	struct net2280		*dev;
	u32			tmp;
	unsigned long		flags;

	if (!_gadget)
		return 0;
	dev = container_of (_gadget, struct net2280, gadget);

	spin_lock_irqsave (&dev->lock, flags);