hc_crisv10.c

usb driver for 2.6.17

		if (urb->bandwidth == 0) {
			bustime = usb_check_bandwidth(urb->dev, urb);
			if (bustime < 0) {
				ret = bustime;
			} else {
				ret = etrax_usb_submit_isoc_urb(urb);
				if (ret == 0)
					usb_claim_bandwidth(urb->dev, urb, bustime, 0);
			}
		} else {
			/* Bandwidth already set. */
			ret = etrax_usb_submit_isoc_urb(urb);
		}
	}

	DBFEXIT;

        if (ret != 0)
          printk("Submit URB error %d\n", ret);

	return ret;
}

static int etrax_usb_unlink_urb(struct urb *urb, int status)
{
	etrax_hc_t *hc;
	etrax_urb_priv_t *urb_priv;
	int epid;
	unsigned int flags;

	DBFENTER;

	if (!urb) {
		return -EINVAL;
	}

	/* Disable interrupts here since a descriptor interrupt for the isoc epid
	   will modify the sb list.  This could possibly be done more granular, but
	   unlink_urb should not be used frequently anyway.
	*/

	save_flags(flags);
	cli();

	if (!urb->dev || !urb->dev->bus) {
		restore_flags(flags);
		return -ENODEV;
	}
	if (!urb->hcpriv) {
		/* This happens if a device driver calls unlink on an urb that
		   was never submitted (lazy driver) or if the urb was completed
		   while unlink was being called. */
		restore_flags(flags);
		return 0;
	}
	if (urb->transfer_flags & URB_ASYNC_UNLINK) {
		/* FIXME. */
		/* If URB_ASYNC_UNLINK is set:
		   unlink
		   move to a separate urb list
		   call complete at next sof with ECONNRESET

		   If not:
		   wait 1 ms
		   unlink
		   call complete with ENOENT
		*/
		warn("URB_ASYNC_UNLINK set, ignoring.");
	}

	/* One might think that urb->status = -EINPROGRESS would be a requirement for unlinking,
	   but that doesn't work for interrupt and isochronous traffic since they are completed
	   repeatedly, and urb->status is set then. That may in itself be a bug though. */

	hc = urb->dev->bus->hcpriv;
	urb_priv = (etrax_urb_priv_t *)urb->hcpriv;
	epid = urb_priv->epid;

	/* Set the urb status (synchronous unlink). */
	urb->status = -ENOENT;
	urb_priv->urb_state = UNLINK;

	if (usb_pipedevice(urb->pipe) == hc->rh.devnum) {
		int ret;
		ret = etrax_rh_unlink_urb(urb);
		DBFEXIT;
		restore_flags(flags);
		return ret;

	} else if (usb_pipetype(urb->pipe) == PIPE_BULK) {

		dbg_bulk("Unlink of bulk urb (0x%lx)", (unsigned long)urb);

		if (TxBulkEPList[epid].command & IO_MASK(USB_EP_command, enable)) {
			/* The EP was enabled, disable it and wait. */
			TxBulkEPList[epid].command &= ~IO_MASK(USB_EP_command, enable);

			/* Ah, the luxury of busy-wait. */
			while (*R_DMA_CH8_SUB0_EP == virt_to_phys(&TxBulkEPList[epid]));
		}
		/* Kicking dummy list out of the party. */
		TxBulkEPList[epid].next = virt_to_phys(&TxBulkEPList[(epid + 1) % NBR_OF_EPIDS]);

	} else if (usb_pipetype(urb->pipe) == PIPE_CONTROL) {

		dbg_ctrl("Unlink of ctrl urb (0x%lx)", (unsigned long)urb);

		if (TxCtrlEPList[epid].command & IO_MASK(USB_EP_command, enable)) {
			/* The EP was enabled, disable it and wait. */
			TxCtrlEPList[epid].command &= ~IO_MASK(USB_EP_command, enable);

			/* Ah, the luxury of busy-wait. */
			while (*R_DMA_CH8_SUB1_EP == virt_to_phys(&TxCtrlEPList[epid]));
		}

	} else if (usb_pipetype(urb->pipe) == PIPE_INTERRUPT) {

		dbg_intr("Unlink of intr urb (0x%lx)", (unsigned long)urb);

		/* Separate function because it's a tad more complicated. */
		etrax_usb_unlink_intr_urb(urb);

	} else if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {

		dbg_isoc("Unlink of isoc urb (0x%lx)", (unsigned long)urb);

		if (TxIsocEPList[epid].command & IO_MASK(USB_EP_command, enable)) {
			/* The EP was enabled, disable it and wait. */
			TxIsocEPList[epid].command &= ~IO_MASK(USB_EP_command, enable);

			/* Ah, the luxury of busy-wait. */
			while (*R_DMA_CH8_SUB3_EP == virt_to_phys(&TxIsocEPList[epid]));
		}
	}

	/* Note that we need to remove the urb from the urb list *before* removing its SB
	   descriptors. (This means that the isoc eof handler might get a null urb when we
	   are unlinking the last urb.) */

	if (usb_pipetype(urb->pipe) == PIPE_BULK) {

		urb_list_del(urb, epid);
		TxBulkEPList[epid].sub = 0;
		etrax_remove_from_sb_list(urb);

	} else if (usb_pipetype(urb->pipe) == PIPE_CONTROL) {

		urb_list_del(urb, epid);
		TxCtrlEPList[epid].sub = 0;
		etrax_remove_from_sb_list(urb);

	} else if (usb_pipetype(urb->pipe) == PIPE_INTERRUPT) {

		urb_list_del(urb, epid);
		/* Sanity check (should never happen). */
		assert(urb_list_empty(epid));

		/* Release allocated bandwidth. */
		usb_release_bandwidth(urb->dev, urb, 0);

	} else if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {

		if (usb_pipeout(urb->pipe)) {

			USB_SB_Desc_t *iter_sb, *prev_sb, *next_sb;

			if (__urb_list_entry(urb, epid)) {

				urb_list_del(urb, epid);
				iter_sb = TxIsocEPList[epid].sub ? phys_to_virt(TxIsocEPList[epid].sub) : 0;
				prev_sb = 0;
				while (iter_sb && (iter_sb != urb_priv->first_sb)) {
					prev_sb = iter_sb;
					iter_sb = iter_sb->next ? phys_to_virt(iter_sb->next) : 0;
				}

				if (iter_sb == 0) {
					/* Unlink of the URB currently being transmitted. */
					prev_sb = 0;
					iter_sb = TxIsocEPList[epid].sub ? phys_to_virt(TxIsocEPList[epid].sub) : 0;
				}

				while (iter_sb && (iter_sb != urb_priv->last_sb)) {
					iter_sb = iter_sb->next ? phys_to_virt(iter_sb->next) : 0;
				}
				if (iter_sb) {
					next_sb = iter_sb->next ? phys_to_virt(iter_sb->next) : 0;
				} else {
					/* This should only happen if the DMA has completed
					   processing the SB list for this EP while interrupts
					   are disabled. */
					dbg_isoc("Isoc urb not found, already sent?");
					next_sb = 0;
				}
				if (prev_sb) {
					prev_sb->next = next_sb ? virt_to_phys(next_sb) : 0;
				} else {
					TxIsocEPList[epid].sub = next_sb ? virt_to_phys(next_sb) : 0;
				}

				etrax_remove_from_sb_list(urb);
				if (urb_list_empty(epid)) {
					TxIsocEPList[epid].sub = 0;
					dbg_isoc("Last isoc out urb epid %d", epid);
				} else if (next_sb || prev_sb) {
					dbg_isoc("Re-enable isoc out epid %d", epid);

					TxIsocEPList[epid].hw_len = 0;
					TxIsocEPList[epid].command |= IO_STATE(USB_EP_command, enable, yes);
				} else {
					TxIsocEPList[epid].sub = 0;
					dbg_isoc("URB list non-empty and no SB list, EP disabled");
				}
			} else {
				dbg_isoc("Urb 0x%p not found, completed already?", urb);
			}
		} else {

			urb_list_del(urb, epid);

			/* For in traffic there is only one SB descriptor for each EP even
			   though there may be several urbs (all urbs point at the same SB). */
			if (urb_list_empty(epid)) {
				/* No more urbs, remove the SB. */
				TxIsocEPList[epid].sub = 0;
				etrax_remove_from_sb_list(urb);
			} else {
				TxIsocEPList[epid].hw_len = 0;
				TxIsocEPList[epid].command |= IO_STATE(USB_EP_command, enable, yes);
			}
		}
		/* Release allocated bandwidth. */
		usb_release_bandwidth(urb->dev, urb, 1);
	}
	/* Free the epid if urb list is empty. */
	if (urb_list_empty(epid)) {
		etrax_usb_free_epid(epid);
	}
	restore_flags(flags);

	/* Must be done before calling completion handler. */
	kfree(urb_priv);
	urb->hcpriv = 0;

	if (urb->complete) {
		urb->complete(urb, NULL);
	}

	DBFEXIT;
	return 0;
}

static int etrax_usb_get_frame_number(struct usb_device *usb_dev)
{
	DBFENTER;
	DBFEXIT;
	return (*R_USB_FM_NUMBER & 0x7ff);
}

static irqreturn_t etrax_usb_tx_interrupt(int irq, void *vhc, struct pt_regs *regs)
{
	DBFENTER;

	/* This interrupt handler could be used when unlinking EP descriptors. */

	if (*R_IRQ_READ2 & IO_MASK(R_IRQ_READ2, dma8_sub0_descr)) {
		USB_EP_Desc_t *ep;

		//dbg_bulk("dma8_sub0_descr (BULK) intr.");

		/* It should be safe clearing the interrupt here, since we don't expect to get a new
		   one until we restart the bulk channel. */
		*R_DMA_CH8_SUB0_CLR_INTR = IO_STATE(R_DMA_CH8_SUB0_CLR_INTR, clr_descr, do);

		/* Wait while the DMA is running (though we don't expect it to be). */
		while (*R_DMA_CH8_SUB0_CMD & IO_MASK(R_DMA_CH8_SUB0_CMD, cmd));

		/* Advance the DMA to the next EP descriptor. */
		ep = (USB_EP_Desc_t *)phys_to_virt(*R_DMA_CH8_SUB0_EP);

		//dbg_bulk("descr intr: DMA is at 0x%lx", (unsigned long)ep);

		/* ep->next is already a physical address; no need for a virt_to_phys. */
		*R_DMA_CH8_SUB0_EP = ep->next;

		/* Start the DMA bulk channel again. */
		*R_DMA_CH8_SUB0_CMD = IO_STATE(R_DMA_CH8_SUB0_CMD, cmd, start);
	}
	if (*R_IRQ_READ2 & IO_MASK(R_IRQ_READ2, dma8_sub1_descr)) {
		struct urb *urb;
		int epid;
		etrax_urb_priv_t *urb_priv;
		unsigned long int flags;

		dbg_ctrl("dma8_sub1_descr (CTRL) intr.");
		*R_DMA_CH8_SUB1_CLR_INTR = IO_STATE(R_DMA_CH8_SUB1_CLR_INTR, clr_descr, do);

		/* The complete callback gets called so we cli. */
		save_flags(flags);
		cli();

		for (epid = 0; epid < NBR_OF_EPIDS - 1; epid++) {
			if ((TxCtrlEPList[epid].sub == 0) ||
			    (epid == DUMMY_EPID) ||
			    (epid == INVALID_EPID)) {
				/* Nothing here to see. */
				continue;
			}

			/* Get the first urb (if any). */
			urb = urb_list_first(epid);

			if (urb) {

				/* Sanity check. */
				assert(usb_pipetype(urb->pipe) == PIPE_CONTROL);

				urb_priv = (etrax_urb_priv_t *)urb->hcpriv;
				assert(urb_priv);

				if (urb_priv->urb_state == WAITING_FOR_DESCR_INTR) {
					assert(!(TxCtrlEPList[urb_priv->epid].command & IO_MASK(USB_EP_command, enable)));

					etrax_usb_complete_urb(urb, 0);
				}
			}
		}
		restore_flags(flags);
	}
	if (*R_IRQ_READ2 & IO_MASK(R_IRQ_READ2, dma8_sub2_descr)) {
		dbg_intr("dma8_sub2_descr (INTR) intr.");
		*R_DMA_CH8_SUB2_CLR_INTR = IO_STATE(R_DMA_CH8_SUB2_CLR_INTR, clr_descr, do);
	}
	if (*R_IRQ_READ2 & IO_MASK(R_IRQ_READ2, dma8_sub3_descr)) {
		struct urb *urb;
		int epid;
		int epid_done;
		etrax_urb_priv_t *urb_priv;
		USB_SB_Desc_t *sb_desc;

		usb_isoc_complete_data_t *comp_data = NULL;

		/* One or more isoc out transfers are done. */
		dbg_isoc("dma8_sub3_descr (ISOC) intr.");

		/* For each isoc out EP search for the first sb_desc with the intr flag
		   set.  This descriptor must be the last packet from an URB.  Then
		   traverse the URB list for the EP until the URB with urb_priv->last_sb
		   matching the intr-marked sb_desc is found.  All URBs before this have
		   been sent.
		*/

		for (epid = 0; epid < NBR_OF_EPIDS - 1; epid++) {
			/* Skip past epids with no SB lists, epids used for in traffic,
			   and special (dummy, invalid) epids. */
			if ((TxIsocEPList[epid].sub == 0) ||
			    (test_bit(epid, (void *)&epid_out_traffic) == 0) ||
			    (epid == DUMMY_EPID) ||
			    (epid == INVALID_EPID)) {
				/* Nothing here to see. */
				continue;
			}
			sb_desc = phys_to_virt(TxIsocEPList[epid].sub);

			/* Find the last descriptor of the currently active URB for this ep.
			   This is the first descriptor in the sub list marked for a descriptor
			   interrupt. */
			while (sb_desc && !IO_EXTRACT(USB_SB_command, intr, sb_desc->command)) {
				sb_desc = sb_desc->next ? phys_to_virt(sb_desc->next) : 0;
			}
			assert(sb_desc);

			dbg_isoc("Check epid %d, sub 0x%p, SB 0x%p",
				 epid,
				 phys_to_virt(TxIsocEPList[epid].sub),
				 sb_desc);

			epid_done = 0;

			/* Get the first urb (if any). */
			urb = urb_list_first(epid);
			assert(urb);

			while (urb && !epid_done) {

				/* Sanity check. */
				assert(usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS);

				if (!usb_pipeout(urb->pipe)) {
					/* descr interrupts are generated only for out pipes. */
					epid_done = 1;
					continue;
				}

				urb_priv = (etrax_urb_priv_t *)urb->hcpriv;
				assert(urb_priv);

				if (sb_desc != urb_priv->last_sb) {

					/* This urb has been sent. */
					dbg_isoc("out URB 0x%p sent", urb);

					urb_priv->urb_state = TRANSFER_DONE;

				} else if ((sb_desc == urb_priv->last_sb) &&
					   !(TxIsocEPList[epid].command & IO_MASK(USB_EP_command, enable))) {

					assert((sb_desc->command & IO_MASK(USB_SB_command, eol)) == IO_STATE(USB_SB_command, eol, yes));
					assert(sb_desc->next == 0);

					dbg_isoc("out URB 0x%p last in list, epid disabled", urb);
					TxIsocEPList[epid].sub = 0;
					TxIsocEPList[epid].hw_len = 0;
					urb_priv->urb_state = TRANSFER_DONE;

					epid_done = 1;

				} else {
					epid_done = 1;
				}
				if (!epid_done) {
					urb = urb_list_next(urb, epid);
				}
			}

		}

		*R_DMA_CH8_SUB3_CLR_INTR = IO_STATE(R_DMA_CH8_SUB3_CLR_INTR, clr_descr, do);

		comp_data = (usb_isoc_complete_data_t*)kmem_cache_alloc(isoc_compl_cache, SLAB_ATOMIC);
		assert(comp_data != NULL);

                INIT_WORK(&comp_data->usb_bh, etrax_usb_isoc_descr_interrupt_bottom_half, comp_data);
                schedule_work(&comp_data->usb_bh);
	}

	DBFEXIT;
        return IRQ_HANDLED;