usbdev.c

LINUX 2.6.17.4的源码

	list = &ep->inlist;

	if (!async && list->count) {
		halt_dma(ep->indma);
		flush_pkt_list(list);
	}

	link_tail(ep, list, pkt);

	vdbg("%s: ep%d, pkt=%p, size=%d, list count=%d", __FUNCTION__,
	     ep->address, pkt, pkt->size, list->count);

	if (list->count == 1) {
		/*
		 * if the packet count is one, it means the list was empty,
		 * and no more data will go out this ep until we kick-start
		 * it again.
		 */
		kickstart_send_packet(ep);
	}

	return pkt->size;
}

/*
 * This routine is called to restart reception of a packet.
 * EP spinlock must be held when calling.
 */
static void
kickstart_receive_packet(endpoint_t * ep)
{
	usbdev_pkt_t *pkt;

	// get and link a new packet for next reception
	if (!(pkt = add_packet(ep, &ep->outlist, ep->max_pkt_size))) {
		err("%s: could not alloc new packet", __FUNCTION__);
		return;
	}

	if (get_dma_active_buffer(ep->outdma) == 1) {
		clear_dma_done1(ep->outdma);
		set_dma_count1(ep->outdma, ep->max_pkt_size);
		set_dma_count0(ep->outdma, 0);
		set_dma_addr1(ep->outdma, virt_to_phys(pkt->payload));
		enable_dma_buffer1(ep->outdma);	// reenable
	} else {
		clear_dma_done0(ep->outdma);
		set_dma_count0(ep->outdma, ep->max_pkt_size);
		set_dma_count1(ep->outdma, 0);
		set_dma_addr0(ep->outdma, virt_to_phys(pkt->payload));
		enable_dma_buffer0(ep->outdma);	// reenable
	}
	if (dma_halted(ep->outdma))
		start_dma(ep->outdma);
}


/*
 * This routine is called when a packet in the outlist has been
 * completed (received) and we need to prepare for a new packet
 * to be received. Halts DMA and computes the packet size from the
 * remaining DMA counter. Then prepares a new packet for reception
 * and restarts DMA. FIXME: what if another packet comes in
 * on top of the completed packet? Counter would be wrong.
 * EP spinlock must be held when calling.
 */
static usbdev_pkt_t *
receive_packet_complete(endpoint_t * ep)
{
	usbdev_pkt_t *pkt = ep->outlist.tail;
	u32 cs;

	halt_dma(ep->outdma);

	cs = au_readl(ep->reg->ctrl_stat);

	if (!pkt)
		return NULL;

	pkt->size = ep->max_pkt_size - get_dma_residue(ep->outdma);
	if (pkt->size)
		dma_cache_inv((unsigned long)pkt->payload, pkt->size);
	/*
	 * need to pull out any remaining bytes in the FIFO.
	 */
	endpoint_fifo_read(ep);
	/*
	 * should be drained now, but flush anyway just in case.
	 */
	flush_read_fifo(ep);

	pkt->status = (cs & USBDEV_CS_NAK) ? PKT_STATUS_NAK : PKT_STATUS_ACK;
	if (ep->address == 0 && (cs & USBDEV_CS_SU))
		pkt->status |= PKT_STATUS_SU;

	vdbg("%s: ep%d, %s pkt=%p, size=%d", __FUNCTION__,
	     ep->address, (pkt->status & PKT_STATUS_NAK) ?
	     "NAK" : "ACK", pkt, pkt->size);

	kickstart_receive_packet(ep);

	return pkt;
}


/*
 ****************************************************************************
 * Here starts the standard device request handlers. They are
 * all called by do_setup() via a table of function pointers.
 ****************************************************************************
 */

static ep0_stage_t
do_get_status(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	switch (setup->bRequestType) {
	case 0x80:	// Device
		// FIXME: send device status
		break;
	case 0x81:	// Interface
		// FIXME: send interface status
		break;
	case 0x82:	// End Point
		// FIXME: send endpoint status
		break;
	default:
		// Invalid Command
		endpoint_stall(&dev->ep[0]); // Stall End Point 0
		break;
	}

	return STATUS_STAGE;
}

static ep0_stage_t
do_clear_feature(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	switch (setup->bRequestType) {
	case 0x00:	// Device
		if ((le16_to_cpu(setup->wValue) & 0xff) == 1)
			dev->remote_wakeup_en = 0;
	else
			endpoint_stall(&dev->ep[0]);
		break;
	case 0x02:	// End Point
		if ((le16_to_cpu(setup->wValue) & 0xff) == 0) {
			endpoint_t *ep =
				epaddr_to_ep(dev,
					     le16_to_cpu(setup->wIndex) & 0xff);

			endpoint_unstall(ep);
			endpoint_reset_datatoggle(ep);
		} else
			endpoint_stall(&dev->ep[0]);
		break;
	}

	return SETUP_STAGE;
}

static ep0_stage_t
do_reserved(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	// Invalid request, stall End Point 0
	endpoint_stall(&dev->ep[0]);
	return SETUP_STAGE;
}

static ep0_stage_t
do_set_feature(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	switch (setup->bRequestType) {
	case 0x00:	// Device
		if ((le16_to_cpu(setup->wValue) & 0xff) == 1)
			dev->remote_wakeup_en = 1;
		else
			endpoint_stall(&dev->ep[0]);
		break;
	case 0x02:	// End Point
		if ((le16_to_cpu(setup->wValue) & 0xff) == 0) {
			endpoint_t *ep =
				epaddr_to_ep(dev,
					     le16_to_cpu(setup->wIndex) & 0xff);

			endpoint_stall(ep);
		} else
			endpoint_stall(&dev->ep[0]);
		break;
	}

	return SETUP_STAGE;
}

static ep0_stage_t
do_set_address(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	int new_state = dev->state;
	int new_addr = le16_to_cpu(setup->wValue);

	dbg("%s: our address=%d", __FUNCTION__, new_addr);

	if (new_addr > 127) {
			// usb spec doesn't tell us what to do, so just go to
			// default state
		new_state = DEFAULT;
		dev->address = 0;
	} else if (dev->address != new_addr) {
		dev->address = new_addr;
		new_state = ADDRESS;
	}

	if (dev->state != new_state) {
		dev->state = new_state;
		/* inform function layer of usbdev state change */
		dev->func_cb(CB_NEW_STATE, dev->state, dev->cb_data);
	}

	return SETUP_STAGE;
}

static ep0_stage_t
do_get_descriptor(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	int strnum, desc_len = le16_to_cpu(setup->wLength);

		switch (le16_to_cpu(setup->wValue) >> 8) {
		case USB_DT_DEVICE:
			// send device descriptor!
		desc_len = desc_len > dev->dev_desc->bLength ?
			dev->dev_desc->bLength : desc_len;
			dbg("sending device desc, size=%d", desc_len);
		send_packet(dev, alloc_packet(&dev->ep[0], desc_len,
					      dev->dev_desc), 0);
			break;
		case USB_DT_CONFIG:
			// If the config descr index in low-byte of
			// setup->wValue	is valid, send config descr,
			// otherwise stall ep0.
			if ((le16_to_cpu(setup->wValue) & 0xff) == 0) {
				// send config descriptor!
				if (desc_len <= USB_DT_CONFIG_SIZE) {
					dbg("sending partial config desc, size=%d",
					     desc_len);
				send_packet(dev,
					    alloc_packet(&dev->ep[0],
							 desc_len,
							 dev->conf_desc),
					    0);
				} else {
				int len = le16_to_cpu(dev->conf_desc->wTotalLength);
				dbg("sending whole config desc,"
				    " size=%d, our size=%d", desc_len, len);
				desc_len = desc_len > len ? len : desc_len;
				send_packet(dev,
					    alloc_packet(&dev->ep[0],
							 desc_len,
							 dev->full_conf_desc),
					    0);
				}
			} else
			endpoint_stall(&dev->ep[0]);
			break;
		case USB_DT_STRING:
			// If the string descr index in low-byte of setup->wValue
			// is valid, send string descr, otherwise stall ep0.
			strnum = le16_to_cpu(setup->wValue) & 0xff;
			if (strnum >= 0 && strnum < 6) {
				struct usb_string_descriptor *desc =
				dev->str_desc[strnum];
				desc_len = desc_len > desc->bLength ?
					desc->bLength : desc_len;
				dbg("sending string desc %d", strnum);
			send_packet(dev,
				    alloc_packet(&dev->ep[0], desc_len,
						 desc), 0);
			} else
			endpoint_stall(&dev->ep[0]);
			break;
	default:
		// Invalid request
		err("invalid get desc=%d, stalled",
			    le16_to_cpu(setup->wValue) >> 8);
		endpoint_stall(&dev->ep[0]);	// Stall endpoint 0
			break;
		}

	return STATUS_STAGE;
}

static ep0_stage_t
do_set_descriptor(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	// TODO: implement
	// there will be an OUT data stage (the descriptor to set)
	return DATA_STAGE;
}

static ep0_stage_t
do_get_configuration(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	// send dev->configuration
	dbg("sending config");
	send_packet(dev, alloc_packet(&dev->ep[0], 1, &dev->configuration),
		    0);
	return STATUS_STAGE;
}

static ep0_stage_t
do_set_configuration(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	// set active config to low-byte of setup->wValue
	dev->configuration = le16_to_cpu(setup->wValue) & 0xff;
	dbg("set config, config=%d", dev->configuration);
	if (!dev->configuration && dev->state > DEFAULT) {
		dev->state = ADDRESS;
		/* inform function layer of usbdev state change */
		dev->func_cb(CB_NEW_STATE, dev->state, dev->cb_data);
	} else if (dev->configuration == 1) {
		dev->state = CONFIGURED;
		/* inform function layer of usbdev state change */
		dev->func_cb(CB_NEW_STATE, dev->state, dev->cb_data);
	} else {
		// FIXME: "respond with request error" - how?
	}

	return SETUP_STAGE;
}

static ep0_stage_t
do_get_interface(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
		// interface must be zero.
	if ((le16_to_cpu(setup->wIndex) & 0xff) || dev->state == ADDRESS) {
			// FIXME: respond with "request error". how?
	} else if (dev->state == CONFIGURED) {
		// send dev->alternate_setting
			dbg("sending alt setting");
		send_packet(dev, alloc_packet(&dev->ep[0], 1,
					      &dev->alternate_setting), 0);
		}

	return STATUS_STAGE;

}

static ep0_stage_t
do_set_interface(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	if (dev->state == ADDRESS) {
			// FIXME: respond with "request error". how?
	} else if (dev->state == CONFIGURED) {
		dev->interface = le16_to_cpu(setup->wIndex) & 0xff;
		dev->alternate_setting =
			    le16_to_cpu(setup->wValue) & 0xff;
			// interface and alternate_setting must be zero
		if (dev->interface || dev->alternate_setting) {
				// FIXME: respond with "request error". how?
			}
		}

	return SETUP_STAGE;
}

static ep0_stage_t
do_synch_frame(struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	// TODO
	return SETUP_STAGE;
}

typedef ep0_stage_t (*req_method_t)(struct usb_dev* dev,
				    struct usb_ctrlrequest* setup);


/* Table of the standard device request handlers */
static const req_method_t req_method[] = {
	do_get_status,
	do_clear_feature,
	do_reserved,
	do_set_feature,
	do_reserved,
	do_set_address,
	do_get_descriptor,
	do_set_descriptor,
	do_get_configuration,
	do_set_configuration,
	do_get_interface,
	do_set_interface,
	do_synch_frame
};


// SETUP packet request dispatcher
static void
do_setup (struct usb_dev* dev, struct usb_ctrlrequest* setup)
{
	req_method_t m;

	dbg("%s: req %d %s", __FUNCTION__, setup->bRequestType,
	    get_std_req_name(setup->bRequestType));

	if ((setup->bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD ||
	    (setup->bRequestType & USB_RECIP_MASK) != USB_RECIP_DEVICE) {
		err("%s: invalid requesttype 0x%02x", __FUNCTION__,
		    setup->bRequestType);
		return;
		}

	if ((setup->bRequestType & 0x80) == USB_DIR_OUT && setup->wLength)
		dbg("%s: OUT phase! length=%d", __FUNCTION__, setup->wLength);

	if (setup->bRequestType < sizeof(req_method)/sizeof(req_method_t))
		m = req_method[setup->bRequestType];
			else
		m = do_reserved;

	dev->ep0_stage = (*m)(dev, setup);
}

/*
 * A SETUP, DATA0, or DATA1 packet has been received
 * on the default control endpoint's fifo.
 */
static void
process_ep0_receive (struct usb_dev* dev)
{
	endpoint_t *ep0 = &dev->ep[0];
	usbdev_pkt_t *pkt;

	spin_lock(&ep0->lock);

		// complete packet and prepare a new packet
	pkt = receive_packet_complete(ep0);
	if (!pkt) {
		// FIXME: should  put a warn/err here.
		spin_unlock(&ep0->lock);
			return;
		}

	// unlink immediately from endpoint.
	unlink_head(&ep0->outlist);

	// override current stage if h/w says it's a setup packet
	if (pkt->status & PKT_STATUS_SU)
		dev->ep0_stage = SETUP_STAGE;

	switch (dev->ep0_stage) {
	case SETUP_STAGE:
		vdbg("SU bit is %s in setup stage",
		     (pkt->status & PKT_STATUS_SU) ? "set" : "not set");

			if (pkt->size == sizeof(struct usb_ctrlrequest)) {
#ifdef VDEBUG
			if (pkt->status & PKT_STATUS_ACK)
				vdbg("received SETUP");
				else
				vdbg("received NAK SETUP");
#endif
			do_setup(dev, (struct usb_ctrlrequest*)pkt->payload);
		} else
			err("%s: wrong size SETUP received", __FUNCTION__);
		break;
	case DATA_STAGE:
		/*
		 * this setup has an OUT data stage. Of the standard
		 * device requests, only set_descriptor has this stage,
		 * so this packet is that descriptor. TODO: drop it for
		 * now, set_descriptor not implemented.
		 *
		 * Need to place a byte in the write FIFO here, to prepare
		 * to send a zero-length DATA ack packet to the host in the
		 * STATUS stage.
		 */
		au_writel(0, ep0->reg->write_fifo);
		dbg("received OUT stage DATAx on EP0, size=%d", pkt->size);
		dev->ep0_stage = SETUP_STAGE;
		break;
	case STATUS_STAGE:
		// this setup had an IN data stage, and host is ACK'ing
		// the packet we sent during that stage.
		if (pkt->size != 0)
			warn("received non-zero ACK on EP0??");
#ifdef VDEBUG
		else
			vdbg("received ACK on EP0");
#endif
		dev->ep0_stage = SETUP_STAGE;
		break;
	}

	spin_unlock(&ep0->lock);
	// we're done processing the packet, free it
	kfree(pkt);
}


/*
 * A DATA0/1 packet has been received on one of the OUT endpoints (4 or 5)
 */
static void
process_ep_receive (struct usb_dev* dev, endpoint_t *ep)
{
	usbdev_pkt_t *pkt;

		spin_lock(&ep->lock);
	pkt = receive_packet_complete(ep);
		spin_unlock(&ep->lock);

	dev->func_cb(CB_PKT_COMPLETE, (unsigned long)pkt, dev->cb_data);
}



/* This ISR handles the receive complete and suspend events */
static void
req_sus_intr (int irq, void *dev_id, struct pt_regs *regs)
{
	struct usb_dev *dev = (struct usb_dev *) dev_id;
	u32 status;