uhci.c

讲述linux的初始化过程

	tmp = head->next;
	while (tmp != head) {
		u = list_entry(tmp, struct urb, urb_list);

		tmp = tmp->next;

		if (u->dev == urb->dev &&
		    u->pipe == urb->pipe)
			goto found;
	}
	u = NULL;

found:
	nested_unlock(&uhci->urblist_lock, flags);

	return u;
}

static int uhci_submit_urb(struct urb *urb)
{
	int ret = -EINVAL;
	struct uhci *uhci;
	unsigned long flags;
	struct urb *u;
	int bustime;

	if (!urb)
		return -EINVAL;

	if (!urb->dev || !urb->dev->bus || !urb->dev->bus->hcpriv)
		return -ENODEV;

	uhci = (struct uhci *)urb->dev->bus->hcpriv;

	/* Short circuit the virtual root hub */
	if (usb_pipedevice(urb->pipe) == uhci->rh.devnum)
		return rh_submit_urb(urb);

	u = uhci_find_urb_ep(uhci, urb);
	if (u && !(urb->transfer_flags & USB_QUEUE_BULK))
		return -ENXIO;

	usb_inc_dev_use(urb->dev);
	spin_lock_irqsave(&urb->lock, flags);

	if (!uhci_alloc_urb_priv(urb)) {
		spin_unlock_irqrestore(&urb->lock, flags);
		usb_dec_dev_use(urb->dev);

		return -ENOMEM;
	}

	switch (usb_pipetype(urb->pipe)) {
	case PIPE_CONTROL:
		ret = uhci_submit_control(urb);
		break;
	case PIPE_INTERRUPT:
		if (urb->bandwidth == 0) {	/* not yet checked/allocated */
			bustime = usb_check_bandwidth(urb->dev, urb);
			if (bustime < 0)
				ret = bustime;
			else {
				ret = uhci_submit_interrupt(urb);
				if (ret == -EINPROGRESS)
					usb_claim_bandwidth(urb->dev, urb, bustime, 0);
			}
		} else		/* bandwidth is already set */
			ret = uhci_submit_interrupt(urb);
		break;
	case PIPE_BULK:
		ret = uhci_submit_bulk(urb, u);
		break;
	case PIPE_ISOCHRONOUS:
		if (urb->bandwidth == 0) {	/* not yet checked/allocated */
			if (urb->number_of_packets <= 0) {
				ret = -EINVAL;
				break;
			}
			bustime = usb_check_bandwidth(urb->dev, urb);
			if (bustime < 0) {
				ret = bustime;
				break;
			}

			ret = uhci_submit_isochronous(urb);
			if (ret == -EINPROGRESS)
				usb_claim_bandwidth(urb->dev, urb, bustime, 1);
		} else		/* bandwidth is already set */
			ret = uhci_submit_isochronous(urb);
		break;
	}

	urb->status = ret;

	spin_unlock_irqrestore(&urb->lock, flags);

	if (ret == -EINPROGRESS)
		ret = 0;
	else {
		uhci_unlink_generic(urb);
		usb_dec_dev_use(urb->dev);
	}

	return ret;
}

/*
 * Return the result of a transfer
 *
 * Must be called with urblist_lock acquired
 */
static void uhci_transfer_result(struct urb *urb)
{
	struct usb_device *dev = urb->dev;
	struct urb *turb;
	int proceed = 0, is_ring = 0;
	int ret = -EINVAL;
	unsigned long flags;

	spin_lock_irqsave(&urb->lock, flags);

	switch (usb_pipetype(urb->pipe)) {
	case PIPE_CONTROL:
		ret = uhci_result_control(urb);
		break;
	case PIPE_INTERRUPT:
		ret = uhci_result_interrupt(urb);
		break;
	case PIPE_BULK:
		ret = uhci_result_bulk(urb);
		break;
	case PIPE_ISOCHRONOUS:
		ret = uhci_result_isochronous(urb);
		break;
	}

	urb->status = ret;

	spin_unlock_irqrestore(&urb->lock, flags);

	if (ret == -EINPROGRESS)
		return;

	switch (usb_pipetype(urb->pipe)) {
	case PIPE_CONTROL:
	case PIPE_BULK:
	case PIPE_ISOCHRONOUS:
		/* Release bandwidth for Interrupt or Isoc. transfers */
		/* Spinlock needed ? */
		if (urb->bandwidth)
			usb_release_bandwidth(urb->dev, urb, 1);
		uhci_unlink_generic(urb);
		break;
	case PIPE_INTERRUPT:
		/* Interrupts are an exception */
		if (urb->interval) {
			urb->complete(urb);
			uhci_reset_interrupt(urb);
			return;
		}

		/* Release bandwidth for Interrupt or Isoc. transfers */
		/* Spinlock needed ? */
		if (urb->bandwidth)
			usb_release_bandwidth(urb->dev, urb, 0);
		uhci_unlink_generic(urb);
		break;
	}

	if (urb->next) {
		turb = urb->next;
		do {
			if (turb->status != -EINPROGRESS) {
				proceed = 1;
				break;
			}

			turb = turb->next;
		} while (turb && turb != urb && turb != urb->next);

		if (turb == urb || turb == urb->next)
			is_ring = 1;
	}

	if (urb->complete && !proceed) {
		urb->complete(urb);
		if (!proceed && is_ring)
			uhci_submit_urb(urb);
	}

	if (proceed && urb->next) {
		turb = urb->next;
		do {
			if (turb->status != -EINPROGRESS &&
			    uhci_submit_urb(turb) != 0)

			turb = turb->next;
		} while (turb && turb != urb->next);

		if (urb->complete)
			urb->complete(urb);
	}

	/* We decrement the usage count after we're done with everything */
	usb_dec_dev_use(dev);
}

static int uhci_unlink_generic(struct urb *urb)
{
	struct urb_priv *urbp = urb->hcpriv;
	struct uhci *uhci = (struct uhci *)urb->dev->bus->hcpriv;

	if (!urbp)
		return -EINVAL;

	uhci_dec_fsbr(uhci, urb);	/* Safe since it checks */

	uhci_remove_urb_list(uhci, urb);

	if (urbp->qh)
		/* The interrupt loop will reclaim the QH's */
		uhci_remove_qh(uhci, urbp->qh);

	if (!list_empty(&urbp->urb_queue_list))
		uhci_delete_queued_urb(uhci, urb);

	uhci_destroy_urb_priv(urb);

	urb->dev = NULL;

	return 0;
}

static int uhci_unlink_urb(struct urb *urb)
{
	struct uhci *uhci;
	int ret = 0;
	unsigned long flags;

	if (!urb)
		return -EINVAL;

	if (!urb->dev || !urb->dev->bus)
		return -ENODEV;

	uhci = (struct uhci *)urb->dev->bus->hcpriv;

	/* Short circuit the virtual root hub */
	if (usb_pipedevice(urb->pipe) == uhci->rh.devnum)
		return rh_unlink_urb(urb);

	/* Release bandwidth for Interrupt or Isoc. transfers */
	/* Spinlock needed ? */
	if (urb->bandwidth) {
		switch (usb_pipetype(urb->pipe)) {
		case PIPE_INTERRUPT:
			usb_release_bandwidth(urb->dev, urb, 0);
			break;
		case PIPE_ISOCHRONOUS:
			usb_release_bandwidth(urb->dev, urb, 1);
			break;
		default:
			break;
		}
	}

	if (urb->status == -EINPROGRESS) {
		uhci_unlink_generic(urb);

		if (urb->transfer_flags & USB_ASYNC_UNLINK) {
			urb->status = -ECONNABORTED;

			spin_lock_irqsave(&uhci->urb_remove_lock, flags);

			/* Check to see if the remove list is empty */
			if (list_empty(&uhci->urb_remove_list))
				uhci_set_next_interrupt(uhci);
			
			list_add(&urb->urb_list, &uhci->urb_remove_list);

			spin_unlock_irqrestore(&uhci->urb_remove_lock, flags);
		} else {
			urb->status = -ENOENT;

			if (in_interrupt()) {	/* wait at least 1 frame */
				static int errorcount = 10;

				if (errorcount--)
					dbg("uhci_unlink_urb called from interrupt for urb %p", urb);
				udelay(1000);
			} else
				schedule_timeout(1+1*HZ/1000); 

			if (urb->complete)
				urb->complete(urb);
		}
	}

	return ret;
}

static int uhci_fsbr_timeout(struct uhci *uhci, struct urb *urb)
{
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	struct list_head *head, *tmp;

	uhci_dec_fsbr(uhci, urb);

	/* There is a race with updating IOC in here, but it's not worth */
	/*  trying to fix since this is merely an optimization. The only */
	/*  time we'd lose is if the status of the packet got updated */
	/*  and we'd be turning on FSBR next frame anyway, so it's a wash */
	urbp->fsbr_timeout = 1;

	head = &urbp->list;
	tmp = head->next;
	while (tmp != head) {
		struct uhci_td *td = list_entry(tmp, struct uhci_td, list);

		tmp = tmp->next;

		if (td->status & TD_CTRL_ACTIVE) {
			td->status |= TD_CTRL_IOC;
			break;
		}
	}

	return 0;
}

/*
 * uhci_get_current_frame_number()
 *
 * returns the current frame number for a USB bus/controller.
 */
static int uhci_get_current_frame_number(struct usb_device *dev)
{
	struct uhci *uhci = (struct uhci *)dev->bus->hcpriv;

	return inw(uhci->io_addr + USBFRNUM);
}

struct usb_operations uhci_device_operations = {
	uhci_alloc_dev,
	uhci_free_dev,
	uhci_get_current_frame_number,
	uhci_submit_urb,
	uhci_unlink_urb
};

/* -------------------------------------------------------------------
   Virtual Root Hub
   ------------------------------------------------------------------- */

static __u8 root_hub_dev_des[] =
{
 	0x12,			/*  __u8  bLength; */
	0x01,			/*  __u8  bDescriptorType; Device */
	0x00,			/*  __u16 bcdUSB; v1.0 */
	0x01,
	0x09,			/*  __u8  bDeviceClass; HUB_CLASSCODE */
	0x00,			/*  __u8  bDeviceSubClass; */
	0x00,			/*  __u8  bDeviceProtocol; */
	0x08,			/*  __u8  bMaxPacketSize0; 8 Bytes */
	0x00,			/*  __u16 idVendor; */
	0x00,
	0x00,			/*  __u16 idProduct; */
	0x00,
	0x00,			/*  __u16 bcdDevice; */
	0x00,
	0x00,			/*  __u8  iManufacturer; */
	0x02,			/*  __u8  iProduct; */
	0x01,			/*  __u8  iSerialNumber; */
	0x01			/*  __u8  bNumConfigurations; */
};


/* Configuration descriptor */
static __u8 root_hub_config_des[] =
{
	0x09,			/*  __u8  bLength; */
	0x02,			/*  __u8  bDescriptorType; Configuration */
	0x19,			/*  __u16 wTotalLength; */
	0x00,
	0x01,			/*  __u8  bNumInterfaces; */
	0x01,			/*  __u8  bConfigurationValue; */
	0x00,			/*  __u8  iConfiguration; */
	0x40,			/*  __u8  bmAttributes;
					Bit 7: Bus-powered, 6: Self-powered,
					Bit 5 Remote-wakeup, 4..0: resvd */
	0x00,			/*  __u8  MaxPower; */

	/* interface */
	0x09,			/*  __u8  if_bLength; */
	0x04,			/*  __u8  if_bDescriptorType; Interface */
	0x00,			/*  __u8  if_bInterfaceNumber; */
	0x00,			/*  __u8  if_bAlternateSetting; */
	0x01,			/*  __u8  if_bNumEndpoints; */
	0x09,			/*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
	0x00,			/*  __u8  if_bInterfaceSubClass; */
	0x00,			/*  __u8  if_bInterfaceProtocol; */
	0x00,			/*  __u8  if_iInterface; */

	/* endpoint */
	0x07,			/*  __u8  ep_bLength; */
	0x05,			/*  __u8  ep_bDescriptorType; Endpoint */
	0x81,			/*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
	0x03,			/*  __u8  ep_bmAttributes; Interrupt */
	0x08,			/*  __u16 ep_wMaxPacketSize; 8 Bytes */
	0x00,
	0xff			/*  __u8  ep_bInterval; 255 ms */
};

static __u8 root_hub_hub_des[] =
{
	0x09,			/*  __u8  bLength; */
	0x29,			/*  __u8  bDescriptorType; Hub-descriptor */
	0x02,			/*  __u8  bNbrPorts; */
	0x00,			/* __u16  wHubCharacteristics; */
	0x00,
	0x01,			/*  __u8  bPwrOn2pwrGood; 2ms */
	0x00,			/*  __u8  bHubContrCurrent; 0 mA */
	0x00,			/*  __u8  DeviceRemovable; *** 7 Ports max *** */
	0xff			/*  __u8  PortPwrCtrlMask; *** 7 ports max *** */
};

/*-------------------------------------------------------------------------*/
/* prepare Interrupt pipe transaction data; HUB INTERRUPT ENDPOINT */
static int rh_send_irq(struct urb *urb)
{
	int i, len = 1;
	struct uhci *uhci = (struct uhci *)urb->dev->bus->hcpriv;
	unsigned int io_addr = uhci->io_addr;
	__u16 data = 0;

	for (i = 0; i < uhci->rh.numports; i++) {
		data |= ((inw(io_addr + USBPORTSC1 + i * 2) & 0xa) > 0 ? (1 << (i + 1)) : 0);
		len = (i + 1) / 8 + 1;
	}

	*(__u16 *) urb->transfer_buffer = cpu_to_le16(data);
	urb->actual_length = len;
	urb->status = USB_ST_NOERROR;

	if ((data > 0) && (uhci->rh.send != 0)) {
		dbg("root-hub INT complete: port1: %x port2: %x data: %x",
			inw(io_addr + USBPORTSC1), inw(io_addr + USBPORTSC2), data);
		urb->complete(urb);
	}

	return USB_ST_NOERROR;
}

/*-------------------------------------------------------------------------*/
/* Virtual Root Hub INTs are polled by this timer every "interval" ms */
static int rh_init_int_timer(struct urb *urb);

static void rh_int_timer_do(unsigned long ptr)
{
	struct urb *urb = (struct urb *)ptr;
	struct uhci *uhci = (struct uhci *)urb->dev->bus->hcpriv;
	struct list_head *tmp, *head = &uhci->urb_list;
	struct urb_priv *urbp;
	int len;
	unsigned long flags;

	if (uhci->rh.send) {
		len = rh_send_irq(urb);
		if (len > 0) {
			urb->actual_length = len;
			if (urb->complete)
				urb->complete(urb);
		}
	}

	nested_lock(&uhci->urblist_lock, flags);
	tmp = head->next;
	while (tmp != head) {
		struct urb *u = list_entry(tmp, urb_t, urb_list);

		tmp = tmp->next;

		urbp = (struct urb_priv *)u->hcpriv;
		if (urbp) {
			/* Check if the FSBR timed out */
			if (urbp->fsbr && time_after_eq(jiffies, urbp->inserttime + IDLE_TIMEOUT))
				uhci_fsbr_timeout(uhci, u);

			/* Check if the URB timed out */
			if (u->timeout && time_after_eq(jiffies, u->timeout)) {
				u->transfer_flags |= USB_ASYNC_UNLINK | USB_TIMEOUT_KILLED;
				uhci_unlink_urb(u);
			}
		}
	}
	nested_unlock(&uhci->urblist_lock, flags);

	rh_init_int_timer(urb);
}

/*-------------------------------------------------------------------------*/
/* Root Hub INTs are polled by this timer */
static int rh_init_int_timer(struct urb *urb)
{
	struct uhci *uhci = (struct uhci *)urb->dev->bus->hcpriv;

	uhci->rh.interval = urb->interval;
	init_timer(&uhci->rh.rh_int_timer);
	uhci->rh.rh_int_timer.function = rh_int_timer_do;
	uhci->rh.rh_int_timer.data = (unsigned long)urb;
	uhci->rh.rh_int_timer.expires = jiffies + (HZ * (urb->interval < 30 ? 30 : urb->interval)) / 1000;
	add_timer(&uhci->rh.rh_int_timer);

	return 0;
}

/*-------------------------------------------------------------------------*/
#define OK(x)			len = (x); break

#define CLR_RH_PORTSTAT(x) \
	status = inw(io_addr + USBPORTSC1 + 2 * (wIndex-1)); \
	status = (status & 0xfff5) & ~(x); \
	outw(status, io_addr + USBPORTSC1 + 2 * (wIndex-1))

#define SET_RH_PORTSTAT(x) \
	status = inw(io_addr + USBPORTSC1 + 2 * (wIndex-1)); \
	status = (status & 0xfff5) | (x); \
	outw(status, io_addr + USBPORTSC1 + 2 * (wIndex-1))


/*-------------------------------------------------------------------------*/
/*************************
 ** Root Hub Control Pipe
 *************************/

static int rh_submit_urb(struct urb *urb)
{
	struct uhci *uhci = (struct uhci *)urb->dev->bus->hcpriv;
	unsigned int pipe = urb->pipe;
	devrequest *cmd = (devrequest *)urb->setup_packet;
	void *data = urb->transfer_buffer;
	int leni = urb->transfer_buffer_length;
	int len = 0;
	int status = 0;
	int stat = USB_ST_NOERROR;
	int i;
	unsigned int io_addr = uhci->io_addr;
	__u16 cstatus;
	__u16 bmRType_bReq;
	__u16 wValue;
	__u16 wIndex;
	__u16 wLength;

	if (usb_pipetype(pipe) == PIPE_INTERRUPT) {
		uhci->rh.urb = urb;
		uhci->rh.send = 1;
		uhci->rh.interval = urb->interval;
		rh_init_int_timer(urb);

		return USB_ST_NOERROR;
	}

	bmRType_bReq = cmd->requesttype | cmd->request << 8;
	wValue = le16_to_cpu(cmd->value);
	wIndex = le16_to_cpu(cmd->index);
	wLength = le16_to_cpu(cmd->length);

	for (i = 0; i < 8; i++)
		uhci->rh.c_p_r[i] = 0;

	switch (bmRType_bReq) {
		/* Request Destination:
		   without flags: Device,
		   RH_INTERFACE: interface,
		   RH_ENDPOINT: endpoint,
		   RH_CLASS means HUB here,
		   RH_OTHER | RH_CLASS  almost ever means HUB_PORT here
		*/

	case RH_GET_STATUS:
		*(__u16 *)data = cpu_to_le16(1);
		OK(2);
	case RH_GET_STATUS | RH_INTERFACE:
		*(__u16 *)data = cpu_to_le16(0);
		OK(2);
	case RH_GET_STATUS | RH_ENDPOINT:
		*(__u16 *)data = cpu_to_le16(0);
		OK(2);
	case RH_GET_STATUS | RH_CLASS:
		*(__u32 *)data = cpu_to_le32(0);
		OK(4);		/* hub power */
	case RH_GET_STATUS | RH_OTHER | RH_CLASS:
		status = inw(io_addr + USBPORTSC1 + 2 * (wIndex - 1));
		cstatus = ((status & USBPORTSC_CSC) >> (1 - 0)) |
			((status & USBPORTSC_PEC) >> (3 - 1)) |
			(uhci->rh.c_p_r[wIndex - 1] << (0 + 4));
			status = (status & USBPORTSC_CCS) |
			((status & USBPORTSC_PE) >> (2 - 1)) |
			((status & USBPORTSC_SUSP) >> (12 - 2)) |
			((status & USBPORTSC_PR) >> (9 - 4)) |
			(1 << 8) |      /* power on */
			((status & USBPORTSC_LSDA) << (-8 + 9));

		*(__u16 *)data = cpu_to_le16(status);
		*(__u16 *)(data + 2) = cpu_to_le16(cstatus);
		OK(4);
	case RH_CLEAR_FEATURE | RH_ENDPOINT:
		switch (wValue) {
		case RH_ENDPOINT_STALL:
			OK(0);
		}
		break;
	case RH_CLEAR_FEATURE | RH_CLASS:
		switch (wValue) {
		case RH_C_HUB_OVER_CURRENT:
			OK(0);	/* hub power over current */
		}
		break;
	case RH_CLEAR_FEATURE | RH_OTHER | RH_CLASS:
		switch (wValue) {
		case RH_PORT_ENABLE:
			CLR_RH_PORTSTAT(USBPORTSC_PE);
			OK(0);
		case RH_PORT_SUSPEND:
			CLR_RH_PORTSTAT(USBPORTSC_SUSP);
			OK(0);
		case RH_PORT_POWER:
			OK(0);	/* port power */
		case RH_C_PORT_CONNECTION:
			SET_RH_PORTSTAT(USBPORTSC_CSC);
			OK(0);
		case RH_C_PORT_ENABLE:
			SET_RH_PORTSTAT(USBPORTSC_PEC);
			OK(0);
		case RH_C_PORT_SUSPEND:
			/*** WR_RH_PORTSTAT(RH_PS_PSSC); */