serial.c

优龙2410linux2.6.8内核源代码

	if (port == NULL)
		return 0;

	spin_lock_irqsave(&port->port_lock, flags);

	if (port->port_dev != NULL && port->port_open_count > 0
	&& port->port_write_buf != NULL)
		chars = gs_buf_data_avail(port->port_write_buf);

	spin_unlock_irqrestore(&port->port_lock, flags);

	gs_debug("gs_chars_in_buffer: (%d,%p) chars=%d\n",
		port->port_num, tty, chars);

	return chars;
}

/*
 * gs_throttle
 */
static void gs_throttle(struct tty_struct *tty)
{
}

/*
 * gs_unthrottle
 */
static void gs_unthrottle(struct tty_struct *tty)
{
}

/*
 * gs_break
 */
static void gs_break(struct tty_struct *tty, int break_state)
{
}

/*
 * gs_ioctl
 */
static int gs_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct gs_port *port = tty->driver_data;

	if (port == NULL) {
		printk(KERN_ERR "gs_ioctl: NULL port pointer\n");
		return -EIO;
	}

	gs_debug("gs_ioctl: (%d,%p,%p) cmd=0x%4.4x, arg=%lu\n",
		port->port_num, tty, file, cmd, arg);

	/* handle ioctls */

	/* could not handle ioctl */
	return -ENOIOCTLCMD;
}

/*
 * gs_set_termios
 */
static void gs_set_termios(struct tty_struct *tty, struct termios *old)
{
}

/*
* gs_send
*
* This function finds available write requests, calls
* gs_send_packet to fill these packets with data, and
* continues until either there are no more write requests
* available or no more data to send.  This function is
* run whenever data arrives or write requests are available.
*/
static int gs_send(struct gs_dev *dev)
{
	int ret,len;
	unsigned long flags;
	struct usb_ep *ep;
	struct usb_request *req;
	struct gs_req_entry *req_entry;

	if (dev == NULL) {
		printk(KERN_ERR "gs_send: NULL device pointer\n");
		return -ENODEV;
	}

	spin_lock_irqsave(&dev->dev_lock, flags);

	ep = dev->dev_in_ep;

	while(!list_empty(&dev->dev_req_list)) {

		req_entry = list_entry(dev->dev_req_list.next,
			struct gs_req_entry, re_entry);

		req = req_entry->re_req;

		len = gs_send_packet(dev, req->buf, ep->maxpacket);

		if (len > 0) {
gs_debug_level(3, "gs_send: len=%d, 0x%2.2x 0x%2.2x 0x%2.2x ...\n", len, *((unsigned char *)req->buf), *((unsigned char *)req->buf+1), *((unsigned char *)req->buf+2));
			list_del(&req_entry->re_entry);
			req->length = len;
			if ((ret=usb_ep_queue(ep, req, GFP_ATOMIC))) {
				printk(KERN_ERR
				"gs_send: cannot queue read request, ret=%d\n",
					ret);
				break;
			}
		} else {
			break;
		}

	}

	spin_unlock_irqrestore(&dev->dev_lock, flags);

	return 0;
}

/*
 * gs_send_packet
 *
 * If there is data to send, a packet is built in the given
 * buffer and the size is returned.  If there is no data to
 * send, 0 is returned.  If there is any error a negative
 * error number is returned.
 *
 * Called during USB completion routine, on interrupt time.
 *
 * We assume that disconnect will not happen until all completion
 * routines have completed, so we can assume that the dev_port
 * array does not change during the lifetime of this function.
 */
static int gs_send_packet(struct gs_dev *dev, char *packet, unsigned int size)
{
	unsigned int len;
	struct gs_port *port;

	/* TEMPORARY -- only port 0 is supported right now */
	port = dev->dev_port[0];

	if (port == NULL) {
		printk(KERN_ERR
			"gs_send_packet: port=%d, NULL port pointer\n",
			0);
		return -EIO;
	}

	spin_lock(&port->port_lock);

	len = gs_buf_data_avail(port->port_write_buf);
	if (len < size)
		size = len;

	if (size == 0) {
		spin_unlock(&port->port_lock);
		return 0;
	}

	size = gs_buf_get(port->port_write_buf, packet, size);

	wake_up_interruptible(&port->port_tty->write_wait);

	spin_unlock(&port->port_lock);

	return size;
}

/*
 * gs_recv_packet
 *
 * Called for each USB packet received.  Reads the packet
 * header and stuffs the data in the appropriate tty buffer.
 * Returns 0 if successful, or a negative error number.
 *
 * Called during USB completion routine, on interrupt time.
 *
 * We assume that disconnect will not happen until all completion
 * routines have completed, so we can assume that the dev_port
 * array does not change during the lifetime of this function.
 */
static int gs_recv_packet(struct gs_dev *dev, char *packet, unsigned int size)
{
	unsigned int len;
	struct gs_port *port;

	/* TEMPORARY -- only port 0 is supported right now */
	port = dev->dev_port[0];

	if (port == NULL) {
		printk(KERN_ERR "gs_recv_packet: port=%d, NULL port pointer\n",
			port->port_num);
		return -EIO;
	}

	spin_lock(&port->port_lock);

	if (port->port_tty == NULL) {
		printk(KERN_ERR "gs_recv_packet: port=%d, NULL tty pointer\n",
			port->port_num);
		spin_unlock(&port->port_lock);
		return -EIO;
	}

	if (port->port_tty->magic != TTY_MAGIC) {
		printk(KERN_ERR "gs_recv_packet: port=%d, bad tty magic\n",
			port->port_num);
		spin_unlock(&port->port_lock);
		return -EIO;
	}

	len = (unsigned int)(TTY_FLIPBUF_SIZE - port->port_tty->flip.count);
	if (len < size)
		size = len;

	if (size > 0) {
		memcpy(port->port_tty->flip.char_buf_ptr, packet, size);
		port->port_tty->flip.char_buf_ptr += size;
		port->port_tty->flip.count += size;
		tty_flip_buffer_push(port->port_tty);
		wake_up_interruptible(&port->port_tty->read_wait);
	}

	spin_unlock(&port->port_lock);

	return 0;
}

/*
* gs_read_complete
*/
static void gs_read_complete(struct usb_ep *ep, struct usb_request *req)
{
	int ret;
	struct gs_dev *dev = ep->driver_data;

	if (dev == NULL) {
		printk(KERN_ERR "gs_read_complete: NULL device pointer\n");
		return;
	}

	switch(req->status) {
	case 0:
 		/* normal completion */
		gs_recv_packet(dev, req->buf, req->actual);
requeue:
		req->length = ep->maxpacket;
		if ((ret=usb_ep_queue(ep, req, GFP_ATOMIC))) {
			printk(KERN_ERR
			"gs_read_complete: cannot queue read request, ret=%d\n",
				ret);
		}
		break;

	case -ESHUTDOWN:
		/* disconnect */
		gs_debug("gs_read_complete: shutdown\n");
		gs_free_req(ep, req);
		break;

	default:
		/* unexpected */
		printk(KERN_ERR
		"gs_read_complete: unexpected status error, status=%d\n",
			req->status);
		goto requeue;
		break;
	}
}

/*
* gs_write_complete
*/
static void gs_write_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct gs_dev *dev = ep->driver_data;
	struct gs_req_entry *gs_req = req->context;

	if (dev == NULL) {
		printk(KERN_ERR "gs_write_complete: NULL device pointer\n");
		return;
	}

	switch(req->status) {
	case 0:
		/* normal completion */
requeue:
		if (gs_req == NULL) {
			printk(KERN_ERR
				"gs_write_complete: NULL request pointer\n");
			return;
		}

		spin_lock(&dev->dev_lock);
		list_add(&gs_req->re_entry, &dev->dev_req_list);
		spin_unlock(&dev->dev_lock);

		gs_send(dev);

		break;

	case -ESHUTDOWN:
		/* disconnect */
		gs_debug("gs_write_complete: shutdown\n");
		gs_free_req(ep, req);
		break;

	default:
		printk(KERN_ERR
		"gs_write_complete: unexpected status error, status=%d\n",
			req->status);
		goto requeue;
		break;
	}
}

/* Gadget Driver */

/*
 * gs_bind
 *
 * Called on module load.  Allocates and initializes the device
 * structure and a control request.
 */
static int gs_bind(struct usb_gadget *gadget)
{
	int ret;
	struct gs_dev *dev;

	gs_device = dev = kmalloc(sizeof(struct gs_dev), GFP_KERNEL);
	if (dev == NULL)
		return -ENOMEM;

	set_gadget_data(gadget, dev);

	memset(dev, 0, sizeof(struct gs_dev));
	dev->dev_gadget = gadget;
	spin_lock_init(&dev->dev_lock);
	INIT_LIST_HEAD(&dev->dev_req_list);

	if ((ret=gs_alloc_ports(dev, GFP_KERNEL)) != 0) {
		printk(KERN_ERR "gs_bind: cannot allocate ports\n");
		gs_unbind(gadget);
		return ret;
	}

	/* preallocate control response and buffer */
	dev->dev_ctrl_req = gs_alloc_req(gadget->ep0, GS_MAX_DESC_LEN,
		GFP_KERNEL);
	if (dev->dev_ctrl_req == NULL) {
		gs_unbind(gadget);
		return -ENOMEM;
	}
	dev->dev_ctrl_req->complete = gs_setup_complete;

	gadget->ep0->driver_data = dev;

	printk(KERN_INFO "gs_bind: %s %s bound\n",
		GS_LONG_NAME, GS_VERSION_STR);

	return 0;
}

/*
 * gs_unbind
 *
 * Called on module unload.  Frees the control request and device
 * structure.
 */
static void gs_unbind(struct usb_gadget *gadget)
{
	struct gs_dev *dev = get_gadget_data(gadget);

	gs_device = NULL;

	/* read/write requests already freed, only control request remains */
	if (dev != NULL) {
		if (dev->dev_ctrl_req != NULL)
			gs_free_req(gadget->ep0, dev->dev_ctrl_req);
		gs_free_ports(dev);
		kfree(dev);
		set_gadget_data(gadget, NULL);
	}

	printk(KERN_INFO "gs_unbind: %s %s unbound\n", GS_LONG_NAME,
		GS_VERSION_STR);
}

/*
 * gs_setup
 *
 * Implements all the control endpoint functionality that's not
 * handled in hardware or the hardware driver.
 *
 * Returns the size of the data sent to the host, or a negative
 * error number.
 */
static int gs_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
{
	int ret = -EOPNOTSUPP;
	unsigned int sv_config;
	struct gs_dev *dev = get_gadget_data(gadget);
	struct usb_request *req = dev->dev_ctrl_req;

	switch (ctrl->bRequest) {
	case USB_REQ_GET_DESCRIPTOR:
		if (ctrl->bRequestType != USB_DIR_IN)
			break;

		switch (ctrl->wValue >> 8) {
		case USB_DT_DEVICE:
			ret = min(ctrl->wLength,
				(u16)sizeof(struct usb_device_descriptor));
			memcpy(req->buf, &gs_device_desc, ret);
			break;

#ifdef HIGHSPEED
		case USB_DT_DEVICE_QUALIFIER:
			ret = min(ctrl->wLength,
				(u16)sizeof(struct usb_qualifier_descriptor));
			memcpy(req->buf, &gs_qualifier_desc, ret);
			break;

		case USB_DT_OTHER_SPEED_CONFIG:
#endif /* HIGHSPEED */
		case USB_DT_CONFIG:
			ret = gs_build_config_desc(req->buf, gadget->speed,
				ctrl->wValue >> 8, ctrl->wValue & 0xff);
			if (ret >= 0)
				ret = min(ctrl->wLength, (u16)ret);
			break;

		case USB_DT_STRING:
			/* wIndex == language code. */
			ret = usb_gadget_get_string(&gs_string_table,
				ctrl->wValue & 0xff, req->buf);
			if (ret >= 0)
				ret = min(ctrl->wLength, (u16)ret);
			break;
		}
		break;

	case USB_REQ_SET_CONFIGURATION:
		if (ctrl->bRequestType != 0)
			break;
		spin_lock(&dev->dev_lock);
		ret = gs_set_config(dev, ctrl->wValue);
		spin_unlock(&dev->dev_lock);
		break;

	case USB_REQ_GET_CONFIGURATION:
		if (ctrl->bRequestType != USB_DIR_IN)
			break;
		*(u8 *)req->buf = dev->dev_config;
		ret = min(ctrl->wLength, (u16)1);
		break;

	case USB_REQ_SET_INTERFACE:
		if (ctrl->bRequestType != USB_RECIP_INTERFACE)
			break;
		spin_lock(&dev->dev_lock);
		if (dev->dev_config == GS_BULK_CONFIG_ID
		&& ctrl->wIndex == GS_INTERFACE_ID
		&& ctrl->wValue == GS_ALT_INTERFACE_ID) {
			sv_config = dev->dev_config;
			/* since there is only one interface, setting the */
			/* interface is equivalent to setting the config */
			gs_reset_config(dev);
			gs_set_config(dev, sv_config);
			ret = 0;
		}
		spin_unlock(&dev->dev_lock);
		break;

	case USB_REQ_GET_INTERFACE:
		if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
			break;
		if (dev->dev_config == GS_NO_CONFIG_ID)
			break;
		if (ctrl->wIndex != GS_INTERFACE_ID) {
			ret = -EDOM;
			break;
		}
		*(u8 *)req->buf = GS_ALT_INTERFACE_ID;
		ret = min(ctrl->wLength, (u16)1);
		break;

	default:
		printk(KERN_ERR "gs_setup: unknown request, type=%02x, request=%02x, value=%04x, index=%04x, length=%d\n",
			ctrl->bRequestType, ctrl->bRequest, ctrl->wValue,
			ctrl->wIndex, ctrl->wLength);
		break;

	}

	/* respond with data transfer before status phase? */
	if (ret >= 0) {
		req->length = ret;
		ret = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
		if (ret < 0) {
			printk(KERN_ERR
				"gs_setup: cannot queue response, ret=%d\n",
				ret);
			req->status = 0;
			gs_setup_complete(gadget->ep0, req);
		}
	}

	/* device either stalls (ret < 0) or reports success */
	return ret;
}

/*
 * gs_setup_complete
 */
static void gs_setup_complete(struct usb_ep *ep, struct usb_request *req)
{
	if (req->status || req->actual != req->length) {
		printk(KERN_ERR "gs_setup_complete: status error, status=%d, actual=%d, length=%d\n",
			req->status, req->actual, req->length);
	}
}

/*
 * gs_disconnect
 *
 * Called when the device is disconnected.  Frees the closed
 * ports and disconnects open ports.  Open ports will be freed
 * on close.  Then reallocates the ports for the next connection.
 */
static void gs_disconnect(struct usb_gadget *gadget)
{
	unsigned long flags;
	struct gs_dev *dev = get_gadget_data(gadget);