ohci1394.c

Ieee1394驱动实现

	int ret = -ENOMEM;

	xmit = kmalloc(sizeof(*xmit), GFP_KERNEL);
	if (!xmit)
		return -ENOMEM;

	iso->hostdata = xmit;
	xmit->ohci = iso->host->hostdata;
	xmit->task_active = 0;

	dma_prog_region_init(&xmit->prog);

	prog_size = sizeof(struct iso_xmit_cmd) * iso->buf_packets;

	if (dma_prog_region_alloc(&xmit->prog, prog_size, xmit->ohci->dev))
		goto err;

	ohci1394_init_iso_tasklet(&xmit->task, OHCI_ISO_TRANSMIT,
				  ohci_iso_xmit_task, (unsigned long) iso);

	if (ohci1394_register_iso_tasklet(xmit->ohci, &xmit->task) < 0) {
		ret = -EBUSY;
		goto err;
	}

	xmit->task_active = 1;

	/* xmit context registers are spaced 16 bytes apart */
	ctx = xmit->task.context;
	xmit->ContextControlSet = OHCI1394_IsoXmitContextControlSet + 16 * ctx;
	xmit->ContextControlClear = OHCI1394_IsoXmitContextControlClear + 16 * ctx;
	xmit->CommandPtr = OHCI1394_IsoXmitCommandPtr + 16 * ctx;

	return 0;

err:
	ohci_iso_xmit_shutdown(iso);
	return ret;
}

static void ohci_iso_xmit_stop(struct hpsb_iso *iso)
{
	struct ohci_iso_xmit *xmit = iso->hostdata;
	struct ti_ohci *ohci = xmit->ohci;

	/* disable interrupts */
	reg_write(xmit->ohci, OHCI1394_IsoXmitIntMaskClear, 1 << xmit->task.context);

	/* halt DMA */
	if (ohci1394_stop_context(xmit->ohci, xmit->ContextControlClear, NULL)) {
		/* XXX the DMA context will lock up if you try to send too much data! */
		PRINT(KERN_ERR,
		      "you probably exceeded the OHCI card's bandwidth limit - "
		      "reload the module and reduce xmit bandwidth");
	}
}

static void ohci_iso_xmit_shutdown(struct hpsb_iso *iso)
{
	struct ohci_iso_xmit *xmit = iso->hostdata;

	if (xmit->task_active) {
		ohci_iso_xmit_stop(iso);
		ohci1394_unregister_iso_tasklet(xmit->ohci, &xmit->task);
		xmit->task_active = 0;
	}

	dma_prog_region_free(&xmit->prog);
	kfree(xmit);
	iso->hostdata = NULL;
}

static void ohci_iso_xmit_task(unsigned long data)
{
	struct hpsb_iso *iso = (struct hpsb_iso*) data;
	struct ohci_iso_xmit *xmit = iso->hostdata;
	struct ti_ohci *ohci = xmit->ohci;
	int wake = 0;
	int count;

	/* check the whole buffer if necessary, starting at pkt_dma */
	for (count = 0; count < iso->buf_packets; count++) {
		int cycle;

		/* DMA descriptor */
		struct iso_xmit_cmd *cmd = dma_region_i(&xmit->prog, struct iso_xmit_cmd, iso->pkt_dma);

		/* check for new writes to xferStatus */
		u16 xferstatus = le32_to_cpu(cmd->output_last.status) >> 16;
		u8  event = xferstatus & 0x1F;

		if (!event) {
			/* packet hasn't been sent yet; we are done for now */
			break;
		}

		if (event != 0x11)
			PRINT(KERN_ERR,
			      "IT DMA error - OHCI error code 0x%02x\n", event);

		/* at least one packet went out, so wake up the writer */
		wake = 1;

		/* parse cycle */
		cycle = le32_to_cpu(cmd->output_last.status) & 0x1FFF;

		/* tell the subsystem the packet has gone out */
		hpsb_iso_packet_sent(iso, cycle, event != 0x11);

		/* reset the DMA descriptor for next time */
		cmd->output_last.status = 0;
	}

	if (wake)
		hpsb_iso_wake(iso);
}

static int ohci_iso_xmit_queue(struct hpsb_iso *iso, struct hpsb_iso_packet_info *info)
{
	struct ohci_iso_xmit *xmit = iso->hostdata;
	struct ti_ohci *ohci = xmit->ohci;

	int next_i, prev_i;
	struct iso_xmit_cmd *next, *prev;

	unsigned int offset;
	unsigned short len;
	unsigned char tag, sy;

	/* check that the packet doesn't cross a page boundary
	   (we could allow this if we added OUTPUT_MORE descriptor support) */
	if (cross_bound(info->offset, info->len)) {
		PRINT(KERN_ERR,
		      "rawiso xmit: packet %u crosses a page boundary",
		      iso->first_packet);
		return -EINVAL;
	}

	offset = info->offset;
	len = info->len;
	tag = info->tag;
	sy = info->sy;

	/* sync up the card's view of the buffer */
	dma_region_sync_for_device(&iso->data_buf, offset, len);

	/* append first_packet to the DMA chain */
	/* by linking the previous descriptor to it */
	/* (next will become the new end of the DMA chain) */

	next_i = iso->first_packet;
	prev_i = (next_i == 0) ? (iso->buf_packets - 1) : (next_i - 1);

	next = dma_region_i(&xmit->prog, struct iso_xmit_cmd, next_i);
	prev = dma_region_i(&xmit->prog, struct iso_xmit_cmd, prev_i);

	/* set up the OUTPUT_MORE_IMMEDIATE descriptor */
	memset(next, 0, sizeof(struct iso_xmit_cmd));
	next->output_more_immediate.control = cpu_to_le32(0x02000008);

	/* ISO packet header is embedded in the OUTPUT_MORE_IMMEDIATE */

	/* tcode = 0xA, and sy */
	next->iso_hdr[0] = 0xA0 | (sy & 0xF);

	/* tag and channel number */
	next->iso_hdr[1] = (tag << 6) | (iso->channel & 0x3F);

	/* transmission speed */
	next->iso_hdr[2] = iso->speed & 0x7;

	/* payload size */
	next->iso_hdr[6] = len & 0xFF;
	next->iso_hdr[7] = len >> 8;

	/* set up the OUTPUT_LAST */
	next->output_last.control = cpu_to_le32(1 << 28);
	next->output_last.control |= cpu_to_le32(1 << 27); /* update timeStamp */
	next->output_last.control |= cpu_to_le32(3 << 20); /* want interrupt */
	next->output_last.control |= cpu_to_le32(3 << 18); /* enable branch */
	next->output_last.control |= cpu_to_le32(len);

	/* payload bus address */
	next->output_last.address = cpu_to_le32(dma_region_offset_to_bus(&iso->data_buf, offset));

	/* leave branchAddress at zero for now */

	/* re-write the previous DMA descriptor to chain to this one */

	/* set prev branch address to point to next (Z=3) */
	prev->output_last.branchAddress = cpu_to_le32(
		dma_prog_region_offset_to_bus(&xmit->prog, sizeof(struct iso_xmit_cmd) * next_i) | 3);

	/* disable interrupt, unless required by the IRQ interval */
	if (prev_i % iso->irq_interval) {
		prev->output_last.control &= cpu_to_le32(~(3 << 20)); /* no interrupt */
	} else {
		prev->output_last.control |= cpu_to_le32(3 << 20); /* enable interrupt */
	}

	wmb();

	/* wake DMA in case it is sleeping */
	reg_write(xmit->ohci, xmit->ContextControlSet, 1 << 12);

	/* issue a dummy read of the cycle timer to force all PCI
	   writes to be posted immediately */
	mb();
	reg_read(xmit->ohci, OHCI1394_IsochronousCycleTimer);

	return 0;
}

static int ohci_iso_xmit_start(struct hpsb_iso *iso, int cycle)
{
	struct ohci_iso_xmit *xmit = iso->hostdata;
	struct ti_ohci *ohci = xmit->ohci;

	/* clear out the control register */
	reg_write(xmit->ohci, xmit->ContextControlClear, 0xFFFFFFFF);
	wmb();

	/* address and length of first descriptor block (Z=3) */
	reg_write(xmit->ohci, xmit->CommandPtr,
		  dma_prog_region_offset_to_bus(&xmit->prog, iso->pkt_dma * sizeof(struct iso_xmit_cmd)) | 3);

	/* cycle match */
	if (cycle != -1) {
		u32 start = cycle & 0x1FFF;

		/* 'cycle' is only mod 8000, but we also need two 'seconds' bits -
		   just snarf them from the current time */
		u32 seconds = reg_read(xmit->ohci, OHCI1394_IsochronousCycleTimer) >> 25;

		/* advance one second to give some extra time for DMA to start */
		seconds += 1;

		start |= (seconds & 3) << 13;

		reg_write(xmit->ohci, xmit->ContextControlSet, 0x80000000 | (start << 16));
	}

	/* enable interrupts */
	reg_write(xmit->ohci, OHCI1394_IsoXmitIntMaskSet, 1 << xmit->task.context);

	/* run */
	reg_write(xmit->ohci, xmit->ContextControlSet, 0x8000);
	mb();

	/* wait 100 usec to give the card time to go active */
	udelay(100);

	/* check the RUN bit */
	if (!(reg_read(xmit->ohci, xmit->ContextControlSet) & 0x8000)) {
		PRINT(KERN_ERR, "Error starting IT DMA (ContextControl 0x%08x)\n",
		      reg_read(xmit->ohci, xmit->ContextControlSet));
		return -1;
	}

	return 0;
}

static int ohci_isoctl(struct hpsb_iso *iso, enum isoctl_cmd cmd, unsigned long arg)
{

	switch(cmd) {
	case XMIT_INIT:
		return ohci_iso_xmit_init(iso);
	case XMIT_START:
		return ohci_iso_xmit_start(iso, arg);
	case XMIT_STOP:
		ohci_iso_xmit_stop(iso);
		return 0;
	case XMIT_QUEUE:
		return ohci_iso_xmit_queue(iso, (struct hpsb_iso_packet_info*) arg);
	case XMIT_SHUTDOWN:
		ohci_iso_xmit_shutdown(iso);
		return 0;

	case RECV_INIT:
		return ohci_iso_recv_init(iso);
	case RECV_START: {
		int *args = (int*) arg;
		return ohci_iso_recv_start(iso, args[0], args[1], args[2]);
	}
	case RECV_STOP:
		ohci_iso_recv_stop(iso);
		return 0;
	case RECV_RELEASE:
		ohci_iso_recv_release(iso, (struct hpsb_iso_packet_info*) arg);
		return 0;
	case RECV_FLUSH:
		ohci_iso_recv_task((unsigned long) iso);
		return 0;
	case RECV_SHUTDOWN:
		ohci_iso_recv_shutdown(iso);
		return 0;
	case RECV_LISTEN_CHANNEL:
		ohci_iso_recv_change_channel(iso, arg, 1);
		return 0;
	case RECV_UNLISTEN_CHANNEL:
		ohci_iso_recv_change_channel(iso, arg, 0);
		return 0;
	case RECV_SET_CHANNEL_MASK:
		ohci_iso_recv_set_channel_mask(iso, *((u64*) arg));
		return 0;

	default:
		PRINT_G(KERN_ERR, "ohci_isoctl cmd %d not implemented yet",
			cmd);
		break;
	}
	return -EINVAL;
}

/***************************************
 * IEEE-1394 functionality section END *
 ***************************************/


/********************************************************
 * Global stuff (interrupt handler, init/shutdown code) *
 ********************************************************/

static void dma_trm_reset(struct dma_trm_ctx *d)
{
	unsigned long flags;
	LIST_HEAD(packet_list);
	struct ti_ohci *ohci = d->ohci;
	struct hpsb_packet *packet, *ptmp;

	ohci1394_stop_context(ohci, d->ctrlClear, NULL);

	/* Lock the context, reset it and release it. Move the packets
	 * that were pending in the context to packet_list and free
	 * them after releasing the lock. */

	spin_lock_irqsave(&d->lock, flags);

	list_splice(&d->fifo_list, &packet_list);
	list_splice(&d->pending_list, &packet_list);
	INIT_LIST_HEAD(&d->fifo_list);
	INIT_LIST_HEAD(&d->pending_list);

	d->branchAddrPtr = NULL;
	d->sent_ind = d->prg_ind;
	d->free_prgs = d->num_desc;

	spin_unlock_irqrestore(&d->lock, flags);

	if (list_empty(&packet_list))
		return;

	PRINT(KERN_INFO, "AT dma reset ctx=%d, aborting transmission", d->ctx);

	/* Now process subsystem callbacks for the packets from this
	 * context. */
	list_for_each_entry_safe(packet, ptmp, &packet_list, driver_list) {
		list_del_init(&packet->driver_list);
		hpsb_packet_sent(ohci->host, packet, ACKX_ABORTED);
	}
}

static void ohci_schedule_iso_tasklets(struct ti_ohci *ohci,
				       quadlet_t rx_event,
				       quadlet_t tx_event)
{
	struct ohci1394_iso_tasklet *t;
	unsigned long mask;
	unsigned long flags;

	spin_lock_irqsave(&ohci->iso_tasklet_list_lock, flags);

	list_for_each_entry(t, &ohci->iso_tasklet_list, link) {
		mask = 1 << t->context;

		if (t->type == OHCI_ISO_TRANSMIT && tx_event & mask)
			tasklet_schedule(&t->tasklet);
		else if (rx_event & mask)
			tasklet_schedule(&t->tasklet);
	}

	spin_unlock_irqrestore(&ohci->iso_tasklet_list_lock, flags);
}

static irqreturn_t ohci_irq_handler(int irq, void *dev_id)
{
	quadlet_t event, node_id;
	struct ti_ohci *ohci = (struct ti_ohci *)dev_id;
	struct hpsb_host *host = ohci->host;
	int phyid = -1, isroot = 0;
	unsigned long flags;

	/* Read and clear the interrupt event register.  Don't clear
	 * the busReset event, though. This is done when we get the
	 * selfIDComplete interrupt. */
	spin_lock_irqsave(&ohci->event_lock, flags);
	event = reg_read(ohci, OHCI1394_IntEventClear);
	reg_write(ohci, OHCI1394_IntEventClear, event & ~OHCI1394_busReset);
	spin_unlock_irqrestore(&ohci->event_lock, flags);

	if (!event)
		return IRQ_NONE;

	/* If event is ~(u32)0 cardbus card was ejected.  In this case
	 * we just return, and clean up in the ohci1394_pci_remove
	 * function. */
	if (event == ~(u32) 0) {
		DBGMSG("Device removed.");
		return IRQ_NONE;
	}

	DBGMSG("IntEvent: %08x", event);

	if (event & OHCI1394_unrecoverableError) {
		int ctx;
		PRINT(KERN_ERR, "Unrecoverable error!");

		if (reg_read(ohci, OHCI1394_AsReqTrContextControlSet) & 0x800)
			PRINT(KERN_ERR, "Async Req Tx Context died: "
				"ctrl[%08x] cmdptr[%08x]",
				reg_read(ohci, OHCI1394_AsReqTrContextControlSet),
				reg_read(ohci, OHCI1394_AsReqTrCommandPtr));

		if (reg_read(ohci, OHCI1394_AsRspTrContextControlSet) & 0x800)
			PRINT(KERN_ERR, "Async Rsp Tx Context died: "
				"ctrl[%08x] cmdptr[%08x]",
				reg_read(ohci, OHCI1394_AsRspTrContextControlSet),
				reg_read(ohci, OHCI1394_AsRspTrCommandPtr));

		if (reg_read(ohci, OHCI1394_AsReqRcvContextControlSet) & 0x800)
			PRINT(KERN_ERR, "Async Req Rcv Context died: "
				"ctrl[%08x] cmdptr[%08x]",
				reg_read(ohci, OHCI1394_AsReqRcvContextControlSet),
				reg_read(ohci, OHCI1394_AsReqRcvCommandPtr));

		if (reg_read(ohci, OHCI1394_AsRspRcvContextControlS