serial.c

优龙2410linux2.6.8内核源代码

	spin_lock_irqsave(&dev->dev_lock, flags);

	gs_reset_config(dev);

	/* free closed ports and disconnect open ports */
	/* (open ports will be freed when closed) */
	gs_free_ports(dev);

	/* re-allocate ports for the next connection */
	if (gs_alloc_ports(dev, GFP_ATOMIC) != 0)
		printk(KERN_ERR "gs_disconnect: cannot re-allocate ports\n");

	spin_unlock_irqrestore(&dev->dev_lock, flags);

	printk(KERN_INFO "gs_disconnect: %s disconnected\n", GS_LONG_NAME);
}

/*
 * gs_set_config
 *
 * Configures the device by enabling device specific
 * optimizations, setting up the endpoints, allocating
 * read and write requests and queuing read requests.
 *
 * The device lock must be held when calling this function.
 */
static int gs_set_config(struct gs_dev *dev, unsigned config)
{
	int i;
	int ret = 0;
	struct usb_gadget *gadget = dev->dev_gadget;
	struct usb_ep *ep;
	struct usb_request *req;
	struct gs_req_entry *req_entry;

	if (dev == NULL) {
		printk(KERN_ERR "gs_set_config: NULL device pointer\n");
		return 0;
	}

	if (config == dev->dev_config)
		return 0;

	gs_reset_config(dev);

	if (config == GS_NO_CONFIG_ID)
		return 0;

	if (config != GS_BULK_CONFIG_ID)
		return -EINVAL;

	hw_optimize(gadget);

	gadget_for_each_ep(ep, gadget) {

		if (strcmp(ep->name, EP_IN_NAME) == 0) {
			ret = usb_ep_enable(ep,
				gadget->speed == USB_SPEED_HIGH ?
 				&gs_highspeed_in_desc : &gs_fullspeed_in_desc);
			if (ret == 0) {
				ep->driver_data = dev;
				dev->dev_in_ep = ep;
			} else {
				printk(KERN_ERR "gs_set_config: cannot enable in endpoint %s, ret=%d\n",
					ep->name, ret);
				gs_reset_config(dev);
				return ret;
			}
		}

		else if (strcmp(ep->name, EP_OUT_NAME) == 0) {
			ret = usb_ep_enable(ep,
				gadget->speed == USB_SPEED_HIGH ?
				&gs_highspeed_out_desc :
				&gs_fullspeed_out_desc);
			if (ret == 0) {
				ep->driver_data = dev;
				dev->dev_out_ep = ep;
			} else {
				printk(KERN_ERR "gs_set_config: cannot enable out endpoint %s, ret=%d\n",
					ep->name, ret);
				gs_reset_config(dev);
				return ret;
			}
		}

	}

	if (dev->dev_in_ep == NULL || dev->dev_out_ep == NULL) {
		gs_reset_config(dev);
		printk(KERN_ERR "gs_set_config: cannot find endpoints\n");
		return -ENODEV;
	}

	/* allocate and queue read requests */
	ep = dev->dev_out_ep;
	for (i=0; i<read_q_size && ret == 0; i++) {
		if ((req=gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC))) {
			req->complete = gs_read_complete;
			if ((ret=usb_ep_queue(ep, req, GFP_ATOMIC))) {
				printk(KERN_ERR "gs_set_config: cannot queue read request, ret=%d\n",
					ret);
			}
		} else {
			gs_reset_config(dev);
			printk(KERN_ERR
			"gs_set_config: cannot allocate read requests\n");
			return -ENOMEM;
		}
	}

	/* allocate write requests, and put on free list */
	ep = dev->dev_in_ep;
	for (i=0; i<write_q_size; i++) {
		if ((req_entry=gs_alloc_req_entry(ep, ep->maxpacket, GFP_ATOMIC))) {
			req_entry->re_req->complete = gs_write_complete;
			list_add(&req_entry->re_entry, &dev->dev_req_list);
		} else {
			gs_reset_config(dev);
			printk(KERN_ERR
			"gs_set_config: cannot allocate write requests\n");
			return -ENOMEM;
		}
	}

	dev->dev_config = config;

	printk(KERN_INFO "gs_set_config: %s configured for %s speed\n",
		GS_LONG_NAME,
		gadget->speed == USB_SPEED_HIGH ? "high" : "full");

	return 0;
}

/*
 * gs_reset_config
 *
 * Mark the device as not configured, disable all endpoints,
 * which forces completion of pending I/O and frees queued
 * requests, and free the remaining write requests on the
 * free list.
 *
 * The device lock must be held when calling this function.
 */
static void gs_reset_config(struct gs_dev *dev)
{
	struct gs_req_entry *req_entry;

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

	if (dev->dev_config == GS_NO_CONFIG_ID)
		return;

	dev->dev_config = GS_NO_CONFIG_ID;

	/* free write requests on the free list */
	while(!list_empty(&dev->dev_req_list)) {
		req_entry = list_entry(dev->dev_req_list.next,
			struct gs_req_entry, re_entry);
		list_del(&req_entry->re_entry);
		gs_free_req_entry(dev->dev_in_ep, req_entry);
	}

	/* disable endpoints, forcing completion of pending i/o; */
	/* completion handlers free their requests in this case */
	if (dev->dev_in_ep) {
		usb_ep_disable(dev->dev_in_ep);
		dev->dev_in_ep = NULL;
	}
	if (dev->dev_out_ep) {
		usb_ep_disable(dev->dev_out_ep);
		dev->dev_out_ep = NULL;
	}
}

/*
 * gs_build_config_desc
 *
 * Builds a config descriptor in the given buffer and returns the
 * length, or a negative error number.
 */
static int gs_build_config_desc(u8 *buf, enum usb_device_speed speed, u8 type, unsigned int index)
{
	int high_speed;
	int len = USB_DT_CONFIG_SIZE + USB_DT_INTERFACE_SIZE
				+ GS_NUM_ENDPOINTS * USB_DT_ENDPOINT_SIZE;

	/* only one config */
	if (index != 0)
		return -EINVAL;

	memcpy(buf, &gs_config_desc, USB_DT_CONFIG_SIZE);
	((struct usb_config_descriptor *)buf)->bDescriptorType = type;
	((struct usb_config_descriptor *)buf)->wTotalLength = __constant_cpu_to_le16(len);
	buf += USB_DT_CONFIG_SIZE;

	memcpy(buf, &gs_interface_desc, USB_DT_INTERFACE_SIZE);
	buf += USB_DT_INTERFACE_SIZE;

	/* other speed switches high and full speed */
	high_speed = (speed == USB_SPEED_HIGH);
	if (type == USB_DT_OTHER_SPEED_CONFIG)
		high_speed = !high_speed;

	memcpy(buf,
		high_speed ? &gs_highspeed_in_desc : &gs_fullspeed_in_desc,
		USB_DT_ENDPOINT_SIZE);
	buf += USB_DT_ENDPOINT_SIZE;
	memcpy(buf,
		high_speed ? &gs_highspeed_out_desc : &gs_fullspeed_out_desc,
		USB_DT_ENDPOINT_SIZE);

	return len;
}

/*
 * gs_alloc_req
 *
 * Allocate a usb_request and its buffer.  Returns a pointer to the
 * usb_request or NULL if there is an error.
 */
static struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned int len, int kmalloc_flags)
{
	struct usb_request *req;

	if (ep == NULL)
		return NULL;

	req = usb_ep_alloc_request(ep, kmalloc_flags);

	if (req != NULL) {
		req->length = len;
		req->buf = usb_ep_alloc_buffer(ep, len, &req->dma,
			kmalloc_flags);
		if (req->buf == NULL) {
			usb_ep_free_request(ep, req);
			return NULL;
		}
	}

	return req;
}

/*
 * gs_free_req
 *
 * Free a usb_request and its buffer.
 */
static void gs_free_req(struct usb_ep *ep, struct usb_request *req)
{
	if (ep != NULL && req != NULL) {
		if (req->buf != NULL)
			usb_ep_free_buffer(ep, req->buf, req->dma,
				req->length);
		usb_ep_free_request(ep, req);
	}
}

/*
 * gs_alloc_req_entry
 *
 * Allocates a request and its buffer, using the given
 * endpoint, buffer len, and kmalloc flags.
 */
static struct gs_req_entry *gs_alloc_req_entry(struct usb_ep *ep, unsigned len, int kmalloc_flags)
{
	struct gs_req_entry	*req;

	req = kmalloc(sizeof(struct gs_req_entry), kmalloc_flags);
	if (req == NULL)
		return NULL;

	req->re_req = gs_alloc_req(ep, len, kmalloc_flags);
	if (req->re_req == NULL) {
		kfree(req);
		return NULL;
	}

	req->re_req->context = req;

	return req;
}

/*
 * gs_free_req_entry
 *
 * Frees a request and its buffer.
 */
static void gs_free_req_entry(struct usb_ep *ep, struct gs_req_entry *req)
{
	if (ep != NULL && req != NULL) {
		if (req->re_req != NULL)
			gs_free_req(ep, req->re_req);
		kfree(req);
	}
}

/*
 * gs_alloc_ports
 *
 * Allocate all ports and set the gs_dev struct to point to them.
 * Return 0 if successful, or a negative error number.
 *
 * The device lock is normally held when calling this function.
 */
static int gs_alloc_ports(struct gs_dev *dev, int kmalloc_flags)
{
	int i;
	struct gs_port *port;

	if (dev == NULL)
		return -EIO;

	for (i=0; i<GS_NUM_PORTS; i++) {
		if ((port=(struct gs_port *)kmalloc(sizeof(struct gs_port), kmalloc_flags)) == NULL)
			return -ENOMEM;

		memset(port, 0, sizeof(struct gs_port));
		port->port_dev = dev;
		port->port_num = i;
		spin_lock_init(&port->port_lock);
		init_waitqueue_head(&port->port_write_wait);

		dev->dev_port[i] = port;
	}

	return 0;
}

/*
 * gs_free_ports
 *
 * Free all closed ports.  Open ports are disconnected by
 * freeing their write buffers, setting their device pointers
 * and the pointers to them in the device to NULL.  These
 * ports will be freed when closed.
 *
 * The device lock is normally held when calling this function.
 */
static void gs_free_ports(struct gs_dev *dev)
{
	int i;
	unsigned long flags;
	struct gs_port *port;

	if (dev == NULL)
		return;

	for (i=0; i<GS_NUM_PORTS; i++) {
		if ((port=dev->dev_port[i]) != NULL) {
			dev->dev_port[i] = NULL;

			spin_lock_irqsave(&port->port_lock, flags);

			if (port->port_write_buf != NULL) {
				gs_buf_free(port->port_write_buf);
				port->port_write_buf = NULL;
			}

			if (port->port_open_count > 0 || port->port_in_use) {
				port->port_dev = NULL;
				wake_up_interruptible(&port->port_write_wait);
				wake_up_interruptible(&port->port_tty->read_wait);
				wake_up_interruptible(&port->port_tty->write_wait);
			} else {
				kfree(port);
			}

			spin_unlock_irqrestore(&port->port_lock, flags);
		}
	}
}

/* Circular Buffer */

/*
 * gs_buf_alloc
 *
 * Allocate a circular buffer and all associated memory.
 */
static struct gs_buf *gs_buf_alloc(unsigned int size, int kmalloc_flags)
{
	struct gs_buf *gb;

	if (size == 0)
		return NULL;

	gb = (struct gs_buf *)kmalloc(sizeof(struct gs_buf), kmalloc_flags);
	if (gb == NULL)
		return NULL;

	gb->buf_buf = kmalloc(size, kmalloc_flags);
	if (gb->buf_buf == NULL) {
		kfree(gb);
		return NULL;
	}

	gb->buf_size = size;
	gb->buf_get = gb->buf_put = gb->buf_buf;

	return gb;
}

/*
 * gs_buf_free
 *
 * Free the buffer and all associated memory.
 */
void gs_buf_free(struct gs_buf *gb)
{
	if (gb != NULL) {
		if (gb->buf_buf != NULL)
			kfree(gb->buf_buf);
		kfree(gb);
	}
}

/*
 * gs_buf_clear
 *
 * Clear out all data in the circular buffer.
 */
void gs_buf_clear(struct gs_buf *gb)
{
	if (gb != NULL)
		gb->buf_get = gb->buf_put;
		/* equivalent to a get of all data available */
}

/*
 * gs_buf_data_avail
 *
 * Return the number of bytes of data available in the circular
 * buffer.
 */
unsigned int gs_buf_data_avail(struct gs_buf *gb)
{
	if (gb != NULL)
		return (gb->buf_size + gb->buf_put - gb->buf_get) % gb->buf_size;
	else
		return 0;
}

/*
 * gs_buf_space_avail
 *
 * Return the number of bytes of space available in the circular
 * buffer.
 */
unsigned int gs_buf_space_avail(struct gs_buf *gb)
{
	if (gb != NULL)
		return (gb->buf_size + gb->buf_get - gb->buf_put - 1) % gb->buf_size;
	else
		return 0;
}

/*
 * gs_buf_put
 *
 * Copy data data from a user buffer and put it into the circular buffer.
 * Restrict to the amount of space available.
 *
 * Return the number of bytes copied.
 */
unsigned int gs_buf_put(struct gs_buf *gb, const char *buf, unsigned int count)
{
	unsigned int len;

	if (gb == NULL)
		return 0;

	len  = gs_buf_space_avail(gb);
	if (count > len)
		count = len;

	if (count == 0)
		return 0;

	len = gb->buf_buf + gb->buf_size - gb->buf_put;
	if (count > len) {
		memcpy(gb->buf_put, buf, len);
		memcpy(gb->buf_buf, buf+len, count - len);
		gb->buf_put = gb->buf_buf + count - len;
	} else {
		memcpy(gb->buf_put, buf, count);
		if (count < len)
			gb->buf_put += count;
		else /* count == len */
			gb->buf_put = gb->buf_buf;
	}

	return count;
}

/*
 * gs_buf_get
 *
 * Get data from the circular buffer and copy to the given buffer.
 * Restrict to the amount of data available.
 *
 * Return the number of bytes copied.
 */
unsigned int gs_buf_get(struct gs_buf *gb, char *buf, unsigned int count)
{
	unsigned int len;

	if (gb == NULL)
		return 0;

	len = gs_buf_data_avail(gb);
	if (count > len)
		count = len;

	if (count == 0)
		return 0;

	len = gb->buf_buf + gb->buf_size - gb->buf_get;
	if (count > len) {
		memcpy(buf, gb->buf_get, len);
		memcpy(buf+len, gb->buf_buf, count - len);
		gb->buf_get = gb->buf_buf + count - len;
	} else {
		memcpy(buf, gb->buf_get, count);
		if (count < len)
			gb->buf_get += count;
		else /* count == len */
			gb->buf_get = gb->buf_buf;
	}

	return count;
}