uhci-q.c

usb driver for 2.6.17

static int uhci_map_status(int status, int dir_out)
{
	if (!status)
		return 0;
	if (status & TD_CTRL_BITSTUFF)			/* Bitstuff error */
		return -EPROTO;
	if (status & TD_CTRL_CRCTIMEO) {		/* CRC/Timeout */
		if (dir_out)
			return -EPROTO;
		else
			return -EILSEQ;
	}
	if (status & TD_CTRL_BABBLE)			/* Babble */
		return -EOVERFLOW;
	if (status & TD_CTRL_DBUFERR)			/* Buffer error */
		return -ENOSR;
	if (status & TD_CTRL_STALLED)			/* Stalled */
		return -EPIPE;
	WARN_ON(status & TD_CTRL_ACTIVE);		/* Active */
	return 0;
}

/*
 * Control transfers
 */
static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
		struct uhci_qh *qh)
{
	struct uhci_td *td;
	unsigned long destination, status;
	int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
	int len = urb->transfer_buffer_length;
	dma_addr_t data = urb->transfer_dma;
	__le32 *plink;

	/* The "pipe" thing contains the destination in bits 8--18 */
	destination = (urb->pipe & PIPE_DEVEP_MASK) | USB_PID_SETUP;

	/* 3 errors, dummy TD remains inactive */
	status = uhci_maxerr(3);
	if (urb->dev->speed == USB_SPEED_LOW)
		status |= TD_CTRL_LS;

	/*
	 * Build the TD for the control request setup packet
	 */
	td = qh->dummy_td;
	uhci_add_td_to_urb(urb, td);
	uhci_fill_td(td, status, destination | uhci_explen(8),
			urb->setup_dma);
	plink = &td->link;
	status |= TD_CTRL_ACTIVE;

	/*
	 * If direction is "send", change the packet ID from SETUP (0x2D)
	 * to OUT (0xE1).  Else change it from SETUP to IN (0x69) and
	 * set Short Packet Detect (SPD) for all data packets.
	 */
	if (usb_pipeout(urb->pipe))
		destination ^= (USB_PID_SETUP ^ USB_PID_OUT);
	else {
		destination ^= (USB_PID_SETUP ^ USB_PID_IN);
		status |= TD_CTRL_SPD;
	}

	/*
	 * Build the DATA TDs
	 */
	while (len > 0) {
		int pktsze = min(len, maxsze);

		td = uhci_alloc_td(uhci);
		if (!td)
			goto nomem;
		*plink = cpu_to_le32(td->dma_handle);

		/* Alternate Data0/1 (start with Data1) */
		destination ^= TD_TOKEN_TOGGLE;
	
		uhci_add_td_to_urb(urb, td);
		uhci_fill_td(td, status, destination | uhci_explen(pktsze),
				data);
		plink = &td->link;

		data += pktsze;
		len -= pktsze;
	}

	/*
	 * Build the final TD for control status 
	 */
	td = uhci_alloc_td(uhci);
	if (!td)
		goto nomem;
	*plink = cpu_to_le32(td->dma_handle);

	/*
	 * It's IN if the pipe is an output pipe or we're not expecting
	 * data back.
	 */
	destination &= ~TD_TOKEN_PID_MASK;
	if (usb_pipeout(urb->pipe) || !urb->transfer_buffer_length)
		destination |= USB_PID_IN;
	else
		destination |= USB_PID_OUT;

	destination |= TD_TOKEN_TOGGLE;		/* End in Data1 */

	status &= ~TD_CTRL_SPD;

	uhci_add_td_to_urb(urb, td);
	uhci_fill_td(td, status | TD_CTRL_IOC,
			destination | uhci_explen(0), 0);
	plink = &td->link;

	/*
	 * Build the new dummy TD and activate the old one
	 */
	td = uhci_alloc_td(uhci);
	if (!td)
		goto nomem;
	*plink = cpu_to_le32(td->dma_handle);

	uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
	wmb();
	qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);
	qh->dummy_td = td;

	/* Low-speed transfers get a different queue, and won't hog the bus.
	 * Also, some devices enumerate better without FSBR; the easiest way
	 * to do that is to put URBs on the low-speed queue while the device
	 * isn't in the CONFIGURED state. */
	if (urb->dev->speed == USB_SPEED_LOW ||
			urb->dev->state != USB_STATE_CONFIGURED)
		qh->skel = uhci->skel_ls_control_qh;
	else {
		qh->skel = uhci->skel_fs_control_qh;
		uhci_inc_fsbr(uhci, urb);
	}
	return 0;

nomem:
	/* Remove the dummy TD from the td_list so it doesn't get freed */
	uhci_remove_td_from_urb(qh->dummy_td);
	return -ENOMEM;
}

/*
 * If control-IN transfer was short, the status packet wasn't sent.
 * This routine changes the element pointer in the QH to point at the
 * status TD.  It's safe to do this even while the QH is live, because
 * the hardware only updates the element pointer following a successful
 * transfer.  The inactive TD for the short packet won't cause an update,
 * so the pointer won't get overwritten.  The next time the controller
 * sees this QH, it will send the status packet.
 */
static int usb_control_retrigger_status(struct uhci_hcd *uhci, struct urb *urb)
{
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	struct uhci_td *td;

	urbp->short_transfer = 1;

	td = list_entry(urbp->td_list.prev, struct uhci_td, list);
	urbp->qh->element = cpu_to_le32(td->dma_handle);

	return -EINPROGRESS;
}


static int uhci_result_control(struct uhci_hcd *uhci, struct urb *urb)
{
	struct list_head *tmp, *head;
	struct urb_priv *urbp = urb->hcpriv;
	struct uhci_td *td;
	unsigned int status;
	int ret = 0;

	head = &urbp->td_list;
	if (urbp->short_transfer) {
		tmp = head->prev;
		goto status_stage;
	}

	urb->actual_length = 0;

	tmp = head->next;
	td = list_entry(tmp, struct uhci_td, list);

	/* The first TD is the SETUP stage, check the status, but skip */
	/*  the count */
	status = uhci_status_bits(td_status(td));
	if (status & TD_CTRL_ACTIVE)
		return -EINPROGRESS;

	if (status)
		goto td_error;

	/* The rest of the TDs (but the last) are data */
	tmp = tmp->next;
	while (tmp != head && tmp->next != head) {
		unsigned int ctrlstat;

		td = list_entry(tmp, struct uhci_td, list);
		tmp = tmp->next;

		ctrlstat = td_status(td);
		status = uhci_status_bits(ctrlstat);
		if (status & TD_CTRL_ACTIVE)
			return -EINPROGRESS;

		urb->actual_length += uhci_actual_length(ctrlstat);

		if (status)
			goto td_error;

		/* Check to see if we received a short packet */
		if (uhci_actual_length(ctrlstat) <
				uhci_expected_length(td_token(td))) {
			if (urb->transfer_flags & URB_SHORT_NOT_OK) {
				ret = -EREMOTEIO;
				goto err;
			}

			return usb_control_retrigger_status(uhci, urb);
		}
	}

status_stage:
	td = list_entry(tmp, struct uhci_td, list);

	/* Control status stage */
	status = td_status(td);

#ifdef I_HAVE_BUGGY_APC_BACKUPS
	/* APC BackUPS Pro kludge */
	/* It tries to send all of the descriptor instead of the amount */
	/*  we requested */
	if (status & TD_CTRL_IOC &&	/* IOC is masked out by uhci_status_bits */
	    status & TD_CTRL_ACTIVE &&
	    status & TD_CTRL_NAK)
		return 0;
#endif

	status = uhci_status_bits(status);
	if (status & TD_CTRL_ACTIVE)
		return -EINPROGRESS;

	if (status)
		goto td_error;

	return 0;

td_error:
	ret = uhci_map_status(status, uhci_packetout(td_token(td)));

err:
	if ((debug == 1 && ret != -EPIPE) || debug > 1) {
		/* Some debugging code */
		dev_dbg(uhci_dev(uhci), "%s: failed with status %x\n",
				__FUNCTION__, status);

		if (errbuf) {
			/* Print the chain for debugging purposes */
			uhci_show_qh(urbp->qh, errbuf, ERRBUF_LEN, 0);
			lprintk(errbuf);
		}
	}

	/* Note that the queue has stopped */
	urbp->qh->element = UHCI_PTR_TERM;
	urbp->qh->is_stopped = 1;
	return ret;
}

/*
 * Common submit for bulk and interrupt
 */
static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
		struct uhci_qh *qh)
{
	struct uhci_td *td;
	unsigned long destination, status;
	int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
	int len = urb->transfer_buffer_length;
	dma_addr_t data = urb->transfer_dma;
	__le32 *plink;
	unsigned int toggle;

	if (len < 0)
		return -EINVAL;

	/* The "pipe" thing contains the destination in bits 8--18 */
	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
	toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
			 usb_pipeout(urb->pipe));

	/* 3 errors, dummy TD remains inactive */
	status = uhci_maxerr(3);
	if (urb->dev->speed == USB_SPEED_LOW)
		status |= TD_CTRL_LS;
	if (usb_pipein(urb->pipe))
		status |= TD_CTRL_SPD;

	/*
	 * Build the DATA TDs
	 */
	plink = NULL;
	td = qh->dummy_td;
	do {	/* Allow zero length packets */
		int pktsze = maxsze;

		if (len <= pktsze) {		/* The last packet */
			pktsze = len;
			if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
				status &= ~TD_CTRL_SPD;
		}

		if (plink) {
			td = uhci_alloc_td(uhci);
			if (!td)
				goto nomem;
			*plink = cpu_to_le32(td->dma_handle);
		}
		uhci_add_td_to_urb(urb, td);
		uhci_fill_td(td, status,
				destination | uhci_explen(pktsze) |
					(toggle << TD_TOKEN_TOGGLE_SHIFT),
				data);
		plink = &td->link;
		status |= TD_CTRL_ACTIVE;

		data += pktsze;
		len -= maxsze;
		toggle ^= 1;
	} while (len > 0);

	/*
	 * URB_ZERO_PACKET means adding a 0-length packet, if direction
	 * is OUT and the transfer_length was an exact multiple of maxsze,
	 * hence (len = transfer_length - N * maxsze) == 0
	 * however, if transfer_length == 0, the zero packet was already
	 * prepared above.
	 */
	if ((urb->transfer_flags & URB_ZERO_PACKET) &&
			usb_pipeout(urb->pipe) && len == 0 &&
			urb->transfer_buffer_length > 0) {
		td = uhci_alloc_td(uhci);
		if (!td)
			goto nomem;
		*plink = cpu_to_le32(td->dma_handle);

		uhci_add_td_to_urb(urb, td);
		uhci_fill_td(td, status,
				destination | uhci_explen(0) |
					(toggle << TD_TOKEN_TOGGLE_SHIFT),
				data);
		plink = &td->link;

		toggle ^= 1;
	}

	/* Set the interrupt-on-completion flag on the last packet.
	 * A more-or-less typical 4 KB URB (= size of one memory page)
	 * will require about 3 ms to transfer; that's a little on the
	 * fast side but not enough to justify delaying an interrupt
	 * more than 2 or 3 URBs, so we will ignore the URB_NO_INTERRUPT
	 * flag setting. */
	td->status |= __constant_cpu_to_le32(TD_CTRL_IOC);

	/*
	 * Build the new dummy TD and activate the old one
	 */
	td = uhci_alloc_td(uhci);
	if (!td)
		goto nomem;
	*plink = cpu_to_le32(td->dma_handle);

	uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
	wmb();
	qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);
	qh->dummy_td = td;

	usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
			usb_pipeout(urb->pipe), toggle);
	return 0;

nomem:
	/* Remove the dummy TD from the td_list so it doesn't get freed */
	uhci_remove_td_from_urb(qh->dummy_td);
	return -ENOMEM;
}

/*
 * Common result for bulk and interrupt
 */
static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
{
	struct urb_priv *urbp = urb->hcpriv;
	struct uhci_td *td;
	unsigned int status = 0;
	int ret = 0;

	urb->actual_length = 0;

	list_for_each_entry(td, &urbp->td_list, list) {
		unsigned int ctrlstat = td_status(td);

		status = uhci_status_bits(ctrlstat);
		if (status & TD_CTRL_ACTIVE)
			return -EINPROGRESS;

		urb->actual_length += uhci_actual_length(ctrlstat);

		if (status)
			goto td_error;

		if (uhci_actual_length(ctrlstat) <
				uhci_expected_length(td_token(td))) {
			if (urb->transfer_flags & URB_SHORT_NOT_OK) {
				ret = -EREMOTEIO;
				goto err;
			}

			/*
			 * This URB stopped short of its end.  We have to
			 * fix up the toggles of the following URBs on the
			 * queue and restart the queue.  But only if this
			 * TD isn't the last one in the URB.
			 *
			 * Do this only the first time we encounter the
			 * short URB.
			 */
			if (!urbp->short_transfer &&
					&td->list != urbp->td_list.prev) {
				urbp->short_transfer = 1;
				urbp->qh->initial_toggle =
						uhci_toggle(td_token(td)) ^ 1;
				uhci_fixup_toggles(urbp->qh, 1);

				td = list_entry(urbp->td_list.prev,
						struct uhci_td, list);
				urbp->qh->element = td->link;
			}
			break;
		}
	}

	return 0;

td_error:
	ret = uhci_map_status(status, uhci_packetout(td_token(td)));

	if ((debug == 1 && ret != -EPIPE) || debug > 1) {
		/* Some debugging code */
		dev_dbg(uhci_dev(uhci), "%s: failed with status %x\n",
				__FUNCTION__, status);

		if (debug > 1 && errbuf) {
			/* Print the chain for debugging purposes */
			uhci_show_qh(urbp->qh, errbuf, ERRBUF_LEN, 0);
			lprintk(errbuf);
		}
	}
err:

	/* Note that the queue has stopped and save the next toggle value */
	urbp->qh->element = UHCI_PTR_TERM;
	urbp->qh->is_stopped = 1;
	urbp->qh->needs_fixup = 1;
	urbp->qh->initial_toggle = uhci_toggle(td_token(td)) ^