serial.c

linux 内核源代码

	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;
	int ret;
	struct tty_struct *tty;

	/* 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_open_count == 0) {
		printk(KERN_ERR "gs_recv_packet: port=%d, port is closed\n",
			port->port_num);
		ret = -EIO;
		goto exit;
	}


	tty = port->port_tty;

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

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

	len = tty_buffer_request_room(tty, size);
	if (len > 0) {
		tty_insert_flip_string(tty, packet, len);
		tty_flip_buffer_push(port->port_tty);
		wake_up_interruptible(&port->port_tty->read_wait);
	}
	ret = 0;
exit:
	spin_unlock(&port->port_lock);
	return ret;
}

/*
* 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 __init gs_bind(struct usb_gadget *gadget)
{
	int ret;
	struct usb_ep *ep;
	struct gs_dev *dev;
	int gcnum;

	/* Some controllers can't support CDC ACM:
	 * - sh doesn't support multiple interfaces or configs;
	 * - sa1100 doesn't have a third interrupt endpoint
	 */
	if (gadget_is_sh(gadget) || gadget_is_sa1100(gadget))
		use_acm = 0;

	gcnum = usb_gadget_controller_number(gadget);
	if (gcnum >= 0)
		gs_device_desc.bcdDevice =
				cpu_to_le16(GS_VERSION_NUM | gcnum);
	else {
		printk(KERN_WARNING "gs_bind: controller '%s' not recognized\n",
			gadget->name);
		/* unrecognized, but safe unless bulk is REALLY quirky */
		gs_device_desc.bcdDevice =
			__constant_cpu_to_le16(GS_VERSION_NUM|0x0099);
	}

	usb_ep_autoconfig_reset(gadget);

	ep = usb_ep_autoconfig(gadget, &gs_fullspeed_in_desc);
	if (!ep)
		goto autoconf_fail;
	EP_IN_NAME = ep->name;
	ep->driver_data = ep;	/* claim the endpoint */

	ep = usb_ep_autoconfig(gadget, &gs_fullspeed_out_desc);
	if (!ep)
		goto autoconf_fail;
	EP_OUT_NAME = ep->name;
	ep->driver_data = ep;	/* claim the endpoint */

	if (use_acm) {
		ep = usb_ep_autoconfig(gadget, &gs_fullspeed_notify_desc);
		if (!ep) {
			printk(KERN_ERR "gs_bind: cannot run ACM on %s\n", gadget->name);
			goto autoconf_fail;
		}
		gs_device_desc.idProduct = __constant_cpu_to_le16(
						GS_CDC_PRODUCT_ID),
		EP_NOTIFY_NAME = ep->name;
		ep->driver_data = ep;	/* claim the endpoint */
	}

	gs_device_desc.bDeviceClass = use_acm
		? USB_CLASS_COMM : USB_CLASS_VENDOR_SPEC;
	gs_device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;

	if (gadget_is_dualspeed(gadget)) {
		gs_qualifier_desc.bDeviceClass = use_acm
			? USB_CLASS_COMM : USB_CLASS_VENDOR_SPEC;
		/* assume ep0 uses the same packet size for both speeds */
		gs_qualifier_desc.bMaxPacketSize0 =
			gs_device_desc.bMaxPacketSize0;
		/* assume endpoints are dual-speed */
		gs_highspeed_notify_desc.bEndpointAddress =
			gs_fullspeed_notify_desc.bEndpointAddress;
		gs_highspeed_in_desc.bEndpointAddress =
			gs_fullspeed_in_desc.bEndpointAddress;
		gs_highspeed_out_desc.bEndpointAddress =
			gs_fullspeed_out_desc.bEndpointAddress;
	}

	usb_gadget_set_selfpowered(gadget);

	if (gadget_is_otg(gadget)) {
		gs_otg_descriptor.bmAttributes |= USB_OTG_HNP,
		gs_bulk_config_desc.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
		gs_acm_config_desc.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	}

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

	snprintf(manufacturer, sizeof(manufacturer), "%s %s with %s",
		init_utsname()->sysname, init_utsname()->release,
		gadget->name);

	dev->dev_gadget = gadget;
	spin_lock_init(&dev->dev_lock);
	INIT_LIST_HEAD(&dev->dev_req_list);
	set_gadget_data(gadget, dev);

	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;

autoconf_fail:
	printk(KERN_ERR "gs_bind: cannot autoconfigure on %s\n", gadget->name);
	return -ENODEV;
}

/*
 * gs_unbind
 *
 * Called on module unload.  Frees the control request and device
 * structure.
 */
static void /* __init_or_exit */ 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);
			dev->dev_ctrl_req = NULL;
		}
		gs_free_ports(dev);
		if (dev->dev_notify_ep)
			usb_ep_disable(dev->dev_notify_ep);
		if (dev->dev_in_ep)
			usb_ep_disable(dev->dev_in_ep);
		if (dev->dev_out_ep)
			usb_ep_disable(dev->dev_out_ep);
		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;
	struct gs_dev *dev = get_gadget_data(gadget);
	struct usb_request *req = dev->dev_ctrl_req;
	u16 wIndex = le16_to_cpu(ctrl->wIndex);
	u16 wValue = le16_to_cpu(ctrl->wValue);
	u16 wLength = le16_to_cpu(ctrl->wLength);

	switch (ctrl->bRequestType & USB_TYPE_MASK) {
	case USB_TYPE_STANDARD:
		ret = gs_setup_standard(gadget,ctrl);
		break;

	case USB_TYPE_CLASS:
		ret = gs_setup_class(gadget,ctrl);
		break;

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

	/* respond with data transfer before status phase? */
	if (ret >= 0) {
		req->length = ret;
		req->zero = ret < wLength
				&& (ret % gadget->ep0->maxpacket) == 0;
		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;
}

static int gs_setup_standard(struct usb_gadget *gadget,
	const struct usb_ctrlrequest *ctrl)
{
	int ret = -EOPNOTSUPP;
	struct gs_dev *dev = get_gadget_data(gadget);
	struct usb_request *req = dev->dev_ctrl_req;
	u16 wIndex = le16_to_cpu(ctrl->wIndex);
	u16 wValue = le16_to_cpu(ctrl->wValue);
	u16 wLength = le16_to_cpu(ctrl->wLength);

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

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

		case USB_DT_DEVICE_QUALIFIER:
			if (!gadget_is_dualspeed(gadget))
				break;
			ret = min(wLength,
				(u16)sizeof(struct usb_qualifier_descriptor));
			memcpy(req->buf, &gs_qualifier_desc, ret);
			break;

		case USB_DT_OTHER_SPEED_CONFIG:
			if (!gadget_is_dualspeed(gadget))
				break;
			/* fall through */
		case USB_DT_CONFIG:
			ret = gs_build_config_buf(req->buf, gadget,
				wValue >> 8, wValue & 0xff,
				gadget_is_otg(gadget));
			if (ret >= 0)
				ret = min(wLength, (u16)ret);
			break;

		case USB_DT_STRING:
			/* wIndex == language code. */
			ret = usb_gadget_get_string(&gs_string_table,
				wValue & 0xff, req->buf);
			if (ret >= 0)
				ret = min(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, 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(wLength, (u16)1);
		break;

	case USB_REQ_SET_INTERFACE:
		if (ctrl->bRequestType != USB_RECIP_INTERFACE
				|| !dev->dev_config
				|| wIndex >= GS_MAX_NUM_INTERFACES)
			break;
		if (dev->dev_config == GS_BULK_CONFIG_ID
				&& wIndex != GS_BULK_INTERFACE_ID)
			break;
		/* no alternate interface settings */
		if (wValue != 0)
			break;
		spin_lock(&dev->dev_lock);
		/* PXA hardware partially handles SET_INTERFACE;
		 * we need to kluge around that interference.  */
		if (gadget_is_pxa(gadget)) {
			ret = gs_set_config(dev, use_acm ?
				GS_ACM_CONFIG_ID : GS_BULK_CONFIG_ID);
			goto set_interface_done;
		}
		if (dev->dev_config != GS_BULK_CONFIG_ID
				&& wIndex == GS_CONTROL_INTERFACE_ID) {
			if (dev->dev_notify_ep) {
				usb_ep_disable(dev->dev_notify_ep);
				usb_ep_enable(dev->dev_notify_ep, dev->dev_notify_ep_desc);
			}
		} else {
			usb_ep_disable(dev->dev_in_ep);
			usb_ep_disable(dev->dev_out_ep);
			usb_ep_enable(dev->dev_in_ep, dev->dev_in_ep_desc);
			usb_ep_enable(dev->dev_out_ep, dev->dev_out_ep_desc);
		}
		ret = 0;
set_interface_done:
		spin_unlock(&dev->dev_lock);
		break;

	case USB_REQ_GET_INTERFACE:
		if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE)
		|| dev->dev_config == GS_NO_CONFIG_ID)
			break;
		if (wIndex >= GS_MAX_NUM_INTERFACES
				|| (dev->dev_config == GS_BULK_CONFIG_ID
				&& wIndex != GS_BULK_INTERFACE_ID)) {
			ret = -EDOM;
			break;
		}
		/* no alternate interface settings */
		*(u8 *)req->buf = 0;
		ret = min(wLength, (u16)1);
		break;

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

	return ret;
}

static int gs_setup_class(struct usb_gadget *gadget,
	const struct usb_ctrlrequest *ctrl)
{
	int ret = -EOPNOTSUPP;
	struct gs_dev *dev = get_gadget_data(gadget);
	struct gs_port *port = dev->dev_port[0];	/* ACM only has one port */
	struct usb_request *req = dev->dev_ctrl_req;
	u16 wIndex = le16_to_cpu(ctrl->wIndex);
	u16 wValue = le16_to_cpu(ctrl->wValue);
	u16 wLength = le16_to_cpu(ctrl->wLength);

	switch (ctrl->bRequest) {
	case USB_CDC_REQ_SET_LINE_CODING:
		/* FIXME Submit req to read the data; have its completion
		 * handler copy that data to port->port_line_coding (iff
		 * it's valid) and maybe pass it on.  Until then, fail.
		 */
		printk(KERN_WARNING "gs_setup: set_line_coding "
				"unuspported\n");
		break;

	case USB_CDC_REQ_GET_LINE_CODING:
		port = dev->dev_port[0];	/* ACM only has one port */
		ret = min(wLength,
			(u16)sizeof(struct usb_cdc_line_coding));
		if (port) {
			spin_lock(&port->port_lock);
			memcpy(req->buf, &port->port_line_coding, ret);
			spin_unlock(&port->port_lock);
		}
		break;

	case USB_CDC_REQ_SET_CONTROL_LINE_STATE:
		/* FIXME Submit req to read the data; have its completion
		 * handler use that to set the state (iff it's valid) and
		 * maybe pass it on.  Until then, fail.
		 */
		printk(KERN_WARNING "gs_setup: set_control_line_state "
				"unuspported\n");
		break;

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

	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);

	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 */