usb-serial.c

linux 内核源代码

{
	struct usb_serial_port *port = tty->driver_data;

	if (!port)
		return;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if (!port->open_count) {
		dbg("%s - port not open", __FUNCTION__);
		return;
	}

	/* pass on to the driver specific version of this function if it is available */
	if (port->serial->type->break_ctl)
		port->serial->type->break_ctl(port, break_state);
}

static int serial_read_proc (char *page, char **start, off_t off, int count, int *eof, void *data)
{
	struct usb_serial *serial;
	int length = 0;
	int i;
	off_t begin = 0;
	char tmp[40];

	dbg("%s", __FUNCTION__);
	length += sprintf (page, "usbserinfo:1.0 driver:2.0\n");
	for (i = 0; i < SERIAL_TTY_MINORS && length < PAGE_SIZE; ++i) {
		serial = usb_serial_get_by_index(i);
		if (serial == NULL)
			continue;

		length += sprintf (page+length, "%d:", i);
		if (serial->type->driver.owner)
			length += sprintf (page+length, " module:%s", module_name(serial->type->driver.owner));
		length += sprintf (page+length, " name:\"%s\"", serial->type->description);
		length += sprintf (page+length, " vendor:%04x product:%04x", 
				   le16_to_cpu(serial->dev->descriptor.idVendor), 
				   le16_to_cpu(serial->dev->descriptor.idProduct));
		length += sprintf (page+length, " num_ports:%d", serial->num_ports);
		length += sprintf (page+length, " port:%d", i - serial->minor + 1);

		usb_make_path(serial->dev, tmp, sizeof(tmp));
		length += sprintf (page+length, " path:%s", tmp);
			
		length += sprintf (page+length, "\n");
		if ((length + begin) > (off + count)) {
			usb_serial_put(serial);
			goto done;
		}
		if ((length + begin) < off) {
			begin += length;
			length = 0;
		}
		usb_serial_put(serial);
	}
	*eof = 1;
done:
	if (off >= (length + begin))
		return 0;
	*start = page + (off-begin);
	return ((count < begin+length-off) ? count : begin+length-off);
}

static int serial_tiocmget (struct tty_struct *tty, struct file *file)
{
	struct usb_serial_port *port = tty->driver_data;

	if (!port)
		return -ENODEV;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if (!port->open_count) {
		dbg("%s - port not open", __FUNCTION__);
		return -ENODEV;
	}

	if (port->serial->type->tiocmget)
		return port->serial->type->tiocmget(port, file);

	return -EINVAL;
}

static int serial_tiocmset (struct tty_struct *tty, struct file *file,
			    unsigned int set, unsigned int clear)
{
	struct usb_serial_port *port = tty->driver_data;

	if (!port)
		return -ENODEV;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if (!port->open_count) {
		dbg("%s - port not open", __FUNCTION__);
		return -ENODEV;
	}

	if (port->serial->type->tiocmset)
		return port->serial->type->tiocmset(port, file, set, clear);

	return -EINVAL;
}

/*
 * We would be calling tty_wakeup here, but unfortunately some line
 * disciplines have an annoying habit of calling tty->write from
 * the write wakeup callback (e.g. n_hdlc.c).
 */
void usb_serial_port_softint(struct usb_serial_port *port)
{
	schedule_work(&port->work);
}

static void usb_serial_port_work(struct work_struct *work)
{
	struct usb_serial_port *port =
		container_of(work, struct usb_serial_port, work);
	struct tty_struct *tty;

	dbg("%s - port %d", __FUNCTION__, port->number);
	
	if (!port)
		return;

	tty = port->tty;
	if (!tty)
		return;

	tty_wakeup(tty);
}

static void port_release(struct device *dev)
{
	struct usb_serial_port *port = to_usb_serial_port(dev);

	dbg ("%s - %s", __FUNCTION__, dev->bus_id);
	port_free(port);
}

static void kill_traffic(struct usb_serial_port *port)
{
	usb_kill_urb(port->read_urb);
	usb_kill_urb(port->write_urb);
	/*
	 * This is tricky.
	 * Some drivers submit the read_urb in the
	 * handler for the write_urb or vice versa
	 * this order determines the order in which
	 * usb_kill_urb() must be used to reliably
	 * kill the URBs. As it is unknown here,
	 * both orders must be used in turn.
	 * The call below is not redundant.
	 */
	usb_kill_urb(port->read_urb);
	usb_kill_urb(port->interrupt_in_urb);
	usb_kill_urb(port->interrupt_out_urb);
}

static void port_free(struct usb_serial_port *port)
{
	kill_traffic(port);
	usb_free_urb(port->read_urb);
	usb_free_urb(port->write_urb);
	usb_free_urb(port->interrupt_in_urb);
	usb_free_urb(port->interrupt_out_urb);
	kfree(port->bulk_in_buffer);
	kfree(port->bulk_out_buffer);
	kfree(port->interrupt_in_buffer);
	kfree(port->interrupt_out_buffer);
	flush_scheduled_work();		/* port->work */
	kfree(port);
}

static struct usb_serial * create_serial (struct usb_device *dev, 
					  struct usb_interface *interface,
					  struct usb_serial_driver *driver)
{
	struct usb_serial *serial;

	serial = kzalloc(sizeof(*serial), GFP_KERNEL);
	if (!serial) {
		dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
		return NULL;
	}
	serial->dev = usb_get_dev(dev);
	serial->type = driver;
	serial->interface = interface;
	kref_init(&serial->kref);

	return serial;
}

static const struct usb_device_id *match_dynamic_id(struct usb_interface *intf,
						    struct usb_serial_driver *drv)
{
	struct usb_dynid *dynid;

	spin_lock(&drv->dynids.lock);
	list_for_each_entry(dynid, &drv->dynids.list, node) {
		if (usb_match_one_id(intf, &dynid->id)) {
			spin_unlock(&drv->dynids.lock);
			return &dynid->id;
		}
	}
	spin_unlock(&drv->dynids.lock);
	return NULL;
}

static const struct usb_device_id *get_iface_id(struct usb_serial_driver *drv,
						struct usb_interface *intf)
{
	const struct usb_device_id *id;

	id = usb_match_id(intf, drv->id_table);
	if (id) {
		dbg("static descriptor matches");
		goto exit;
	}
	id = match_dynamic_id(intf, drv);
	if (id)
		dbg("dynamic descriptor matches");
exit:
	return id;
}

static struct usb_serial_driver *search_serial_device(struct usb_interface *iface)
{
	const struct usb_device_id *id;
	struct usb_serial_driver *drv;

	/* Check if the usb id matches a known device */
	list_for_each_entry(drv, &usb_serial_driver_list, driver_list) {
		id = get_iface_id(drv, iface);
		if (id)
			return drv;
	}

	return NULL;
}

int usb_serial_probe(struct usb_interface *interface,
			       const struct usb_device_id *id)
{
	struct usb_device *dev = interface_to_usbdev (interface);
	struct usb_serial *serial = NULL;
	struct usb_serial_port *port;
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_endpoint_descriptor *interrupt_in_endpoint[MAX_NUM_PORTS];
	struct usb_endpoint_descriptor *interrupt_out_endpoint[MAX_NUM_PORTS];
	struct usb_endpoint_descriptor *bulk_in_endpoint[MAX_NUM_PORTS];
	struct usb_endpoint_descriptor *bulk_out_endpoint[MAX_NUM_PORTS];
	struct usb_serial_driver *type = NULL;
	int retval;
	int minor;
	int buffer_size;
	int i;
	int num_interrupt_in = 0;
	int num_interrupt_out = 0;
	int num_bulk_in = 0;
	int num_bulk_out = 0;
	int num_ports = 0;
	int max_endpoints;

	lock_kernel(); /* guard against unloading a serial driver module */
	type = search_serial_device(interface);
	if (!type) {
		unlock_kernel();
		dbg("none matched");
		return -ENODEV;
	}

	serial = create_serial (dev, interface, type);
	if (!serial) {
		unlock_kernel();
		dev_err(&interface->dev, "%s - out of memory\n", __FUNCTION__);
		return -ENOMEM;
	}

	/* if this device type has a probe function, call it */
	if (type->probe) {
		const struct usb_device_id *id;

		if (!try_module_get(type->driver.owner)) {
			unlock_kernel();
			dev_err(&interface->dev, "module get failed, exiting\n");
			kfree (serial);
			return -EIO;
		}

		id = get_iface_id(type, interface);
		retval = type->probe(serial, id);
		module_put(type->driver.owner);

		if (retval) {
			unlock_kernel();
			dbg ("sub driver rejected device");
			kfree (serial);
			return retval;
		}
	}

	/* descriptor matches, let's find the endpoints needed */
	/* check out the endpoints */
	iface_desc = interface->cur_altsetting;
	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
		endpoint = &iface_desc->endpoint[i].desc;

		if (usb_endpoint_is_bulk_in(endpoint)) {
			/* we found a bulk in endpoint */
			dbg("found bulk in on endpoint %d", i);
			bulk_in_endpoint[num_bulk_in] = endpoint;
			++num_bulk_in;
		}

		if (usb_endpoint_is_bulk_out(endpoint)) {
			/* we found a bulk out endpoint */
			dbg("found bulk out on endpoint %d", i);
			bulk_out_endpoint[num_bulk_out] = endpoint;
			++num_bulk_out;
		}

		if (usb_endpoint_is_int_in(endpoint)) {
			/* we found a interrupt in endpoint */
			dbg("found interrupt in on endpoint %d", i);
			interrupt_in_endpoint[num_interrupt_in] = endpoint;
			++num_interrupt_in;
		}

		if (usb_endpoint_is_int_out(endpoint)) {
			/* we found an interrupt out endpoint */
			dbg("found interrupt out on endpoint %d", i);
			interrupt_out_endpoint[num_interrupt_out] = endpoint;
			++num_interrupt_out;
		}
	}

#if defined(CONFIG_USB_SERIAL_PL2303) || defined(CONFIG_USB_SERIAL_PL2303_MODULE)
	/* BEGIN HORRIBLE HACK FOR PL2303 */ 
	/* this is needed due to the looney way its endpoints are set up */
	if (((le16_to_cpu(dev->descriptor.idVendor) == PL2303_VENDOR_ID) &&
	     (le16_to_cpu(dev->descriptor.idProduct) == PL2303_PRODUCT_ID)) ||
	    ((le16_to_cpu(dev->descriptor.idVendor) == ATEN_VENDOR_ID) &&
	     (le16_to_cpu(dev->descriptor.idProduct) == ATEN_PRODUCT_ID)) ||
	    ((le16_to_cpu(dev->descriptor.idVendor) == ALCOR_VENDOR_ID) &&
	     (le16_to_cpu(dev->descriptor.idProduct) == ALCOR_PRODUCT_ID))) {
		if (interface != dev->actconfig->interface[0]) {
			/* check out the endpoints of the other interface*/
			iface_desc = dev->actconfig->interface[0]->cur_altsetting;
			for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
				endpoint = &iface_desc->endpoint[i].desc;
				if (usb_endpoint_is_int_in(endpoint)) {
					/* we found a interrupt in endpoint */
					dbg("found interrupt in for Prolific device on separate interface");
					interrupt_in_endpoint[num_interrupt_in] = endpoint;
					++num_interrupt_in;
				}
			}
		}

		/* Now make sure the PL-2303 is configured correctly.
		 * If not, give up now and hope this hack will work
		 * properly during a later invocation of usb_serial_probe
		 */
		if (num_bulk_in == 0 || num_bulk_out == 0) {
			unlock_kernel();
			dev_info(&interface->dev, "PL-2303 hack: descriptors matched but endpoints did not\n");
			kfree (serial);
			return -ENODEV;
		}
	}
	/* END HORRIBLE HACK FOR PL2303 */
#endif

#ifdef CONFIG_USB_SERIAL_GENERIC
	if (type == &usb_serial_generic_device) {
		num_ports = num_bulk_out;
		if (num_ports == 0) {
			unlock_kernel();
			dev_err(&interface->dev, "Generic device with no bulk out, not allowed.\n");
			kfree (serial);
			return -EIO;
		}
	}
#endif
	if (!num_ports) {
		/* if this device type has a calc_num_ports function, call it */
		if (type->calc_num_ports) {
			if (!try_module_get(type->driver.owner)) {
				unlock_kernel();
				dev_err(&interface->dev, "module get failed, exiting\n");
				kfree (serial);
				return -EIO;
			}
			num_ports = type->calc_num_ports (serial);
			module_put(type->driver.owner);
		}
		if (!num_ports)
			num_ports = type->num_ports;
	}

	serial->num_ports = num_ports;
	serial->num_bulk_in = num_bulk_in;
	serial->num_bulk_out = num_bulk_out;
	serial->num_interrupt_in = num_interrupt_in;
	serial->num_interrupt_out = num_interrupt_out;

	/* check that the device meets the driver's requirements */
	if ((type->num_interrupt_in != NUM_DONT_CARE &&
				type->num_interrupt_in != num_interrupt_in)
			|| (type->num_interrupt_out != NUM_DONT_CARE &&
				type->num_interrupt_out != num_interrupt_out)
			|| (type->num_bulk_in != NUM_DONT_CARE &&
				type->num_bulk_in != num_bulk_in)
			|| (type->num_bulk_out != NUM_DONT_CARE &&
				type->num_bulk_out != num_bulk_out)) {
		dbg("wrong number of endpoints");
		kfree(serial);
		return -EIO;
	}

	/* found all that we need */
	dev_info(&interface->dev, "%s converter detected\n",
			type->description);

	/* create our ports, we need as many as the max endpoints */
	/* we don't use num_ports here cauz some devices have more endpoint pairs than ports */
	max_endpoints = max(num_bulk_in, num_bulk_out);
	max_endpoints = max(max_endpoints, num_interrupt_in);
	max_endpoints = max(max_endpoints, num_interrupt_out);
	max_endpoints = max(max_endpoints, (int)serial->num_ports);
	serial->num_port_pointers = max_endpoints;
	unlock_kernel();