cdc-acm.c

LINUX 2.6.17.4的源码

			buffer = intf->cur_altsetting->endpoint->extra;
		} else {
			err("Zero length descriptor references\n");
			return -EINVAL;
		}
	}

	while (buflen > 0) {
		if (buffer [1] != USB_DT_CS_INTERFACE) {
			err("skipping garbage\n");
			goto next_desc;
		}

		switch (buffer [2]) {
			case USB_CDC_UNION_TYPE: /* we've found it */
				if (union_header) {
					err("More than one union descriptor, skipping ...");
					goto next_desc;
				}
				union_header = (struct usb_cdc_union_desc *)
							buffer;
				break;
			case USB_CDC_COUNTRY_TYPE: /* maybe somehow export */
				break; /* for now we ignore it */
			case USB_CDC_HEADER_TYPE: /* maybe check version */ 
				break; /* for now we ignore it */ 
			case USB_CDC_ACM_TYPE:
				ac_management_function = buffer[3];
				break;
			case USB_CDC_CALL_MANAGEMENT_TYPE:
				call_management_function = buffer[3];
				call_interface_num = buffer[4];
				if ((call_management_function & 3) != 3)
					err("This device cannot do calls on its own. It is no modem.");
				break;
				
			default:
				err("Ignoring extra header, type %d, length %d", buffer[2], buffer[0]);
				break;
			}
next_desc:
		buflen -= buffer[0];
		buffer += buffer[0];
	}

	if (!union_header) {
		if (call_interface_num > 0) {
			dev_dbg(&intf->dev,"No union descriptor, using call management descriptor\n");
			data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
			control_interface = intf;
		} else {
			dev_dbg(&intf->dev,"No union descriptor, giving up\n");
			return -ENODEV;
		}
	} else {
		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
		data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
		if (!control_interface || !data_interface) {
			dev_dbg(&intf->dev,"no interfaces\n");
			return -ENODEV;
		}
	}
	
	if (data_interface_num != call_interface_num)
		dev_dbg(&intf->dev,"Seperate call control interface. That is not fully supported.\n");

skip_normal_probe:

	/*workaround for switched interfaces */
	if (data_interface->cur_altsetting->desc.bInterfaceClass != CDC_DATA_INTERFACE_TYPE) {
		if (control_interface->cur_altsetting->desc.bInterfaceClass == CDC_DATA_INTERFACE_TYPE) {
			struct usb_interface *t;
			dev_dbg(&intf->dev,"Your device has switched interfaces.\n");

			t = control_interface;
			control_interface = data_interface;
			data_interface = t;
		} else {
			return -EINVAL;
		}
	}
	
	if (usb_interface_claimed(data_interface)) { /* valid in this context */
		dev_dbg(&intf->dev,"The data interface isn't available\n");
		return -EBUSY;
	}


	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2)
		return -EINVAL;

	epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
	epread = &data_interface->cur_altsetting->endpoint[0].desc;
	epwrite = &data_interface->cur_altsetting->endpoint[1].desc;


	/* workaround for switched endpoints */
	if ((epread->bEndpointAddress & USB_DIR_IN) != USB_DIR_IN) {
		/* descriptors are swapped */
		struct usb_endpoint_descriptor *t;
		dev_dbg(&intf->dev,"The data interface has switched endpoints\n");
		
		t = epread;
		epread = epwrite;
		epwrite = t;
	}
	dbg("interfaces are valid");
	for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);

	if (minor == ACM_TTY_MINORS) {
		err("no more free acm devices");
		return -ENODEV;
	}

	if (!(acm = kzalloc(sizeof(struct acm), GFP_KERNEL))) {
		dev_dbg(&intf->dev, "out of memory (acm kzalloc)\n");
		goto alloc_fail;
	}

	ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);
	readsize = le16_to_cpu(epread->wMaxPacketSize)*2;
	acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize);
	acm->control = control_interface;
	acm->data = data_interface;
	acm->minor = minor;
	acm->dev = usb_dev;
	acm->ctrl_caps = ac_management_function;
	acm->ctrlsize = ctrlsize;
	acm->readsize = readsize;
	acm->urb_task.func = acm_rx_tasklet;
	acm->urb_task.data = (unsigned long) acm;
	INIT_WORK(&acm->work, acm_softint, acm);
	spin_lock_init(&acm->throttle_lock);
	spin_lock_init(&acm->write_lock);
	spin_lock_init(&acm->read_lock);
	acm->write_ready = 1;
	acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);

	buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
	if (!buf) {
		dev_dbg(&intf->dev, "out of memory (ctrl buffer alloc)\n");
		goto alloc_fail2;
	}
	acm->ctrl_buffer = buf;

	if (acm_write_buffers_alloc(acm) < 0) {
		dev_dbg(&intf->dev, "out of memory (write buffer alloc)\n");
		goto alloc_fail4;
	}

	acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
	if (!acm->ctrlurb) {
		dev_dbg(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
		goto alloc_fail5;
	}
	for (i = 0; i < ACM_NRU; i++) {
		struct acm_ru *rcv = &(acm->ru[i]);

		if (!(rcv->urb = usb_alloc_urb(0, GFP_KERNEL))) {
			dev_dbg(&intf->dev, "out of memory (read urbs usb_alloc_urb)\n");
			goto alloc_fail7;
		}

		rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
		rcv->instance = acm;
	}
	for (i = 0; i < ACM_NRB; i++) {
		struct acm_rb *buf = &(acm->rb[i]);

		// Using usb_buffer_alloc instead of kmalloc as Oliver suggested
		if (!(buf->base = usb_buffer_alloc(acm->dev, readsize, GFP_KERNEL, &buf->dma))) {
			dev_dbg(&intf->dev, "out of memory (read bufs usb_buffer_alloc)\n");
			goto alloc_fail7;
		}
	}
	acm->writeurb = usb_alloc_urb(0, GFP_KERNEL);
	if (!acm->writeurb) {
		dev_dbg(&intf->dev, "out of memory (writeurb kmalloc)\n");
		goto alloc_fail7;
	}

	usb_fill_int_urb(acm->ctrlurb, usb_dev, usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
			 acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm, epctrl->bInterval);
	acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
	acm->ctrlurb->transfer_dma = acm->ctrl_dma;

	usb_fill_bulk_urb(acm->writeurb, usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
			  NULL, acm->writesize, acm_write_bulk, acm);
	acm->writeurb->transfer_flags |= URB_NO_FSBR | URB_NO_TRANSFER_DMA_MAP;

	dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);

	acm_set_control(acm, acm->ctrlout);

	acm->line.dwDTERate = cpu_to_le32(9600);
	acm->line.bDataBits = 8;
	acm_set_line(acm, &acm->line);

	usb_driver_claim_interface(&acm_driver, data_interface, acm);

	usb_get_intf(control_interface);
	tty_register_device(acm_tty_driver, minor, &control_interface->dev);

	acm_table[minor] = acm;
	usb_set_intfdata (intf, acm);
	return 0;

alloc_fail7:
	for (i = 0; i < ACM_NRB; i++)
		usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
	for (i = 0; i < ACM_NRU; i++)
		usb_free_urb(acm->ru[i].urb);
	usb_free_urb(acm->ctrlurb);
alloc_fail5:
	acm_write_buffers_free(acm);
alloc_fail4:
	usb_buffer_free(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
alloc_fail2:
	kfree(acm);
alloc_fail:
	return -ENOMEM;
}

static void acm_disconnect(struct usb_interface *intf)
{
	struct acm *acm = usb_get_intfdata (intf);
	struct usb_device *usb_dev = interface_to_usbdev(intf);
	int i;

	if (!acm || !acm->dev) {
		dbg("disconnect on nonexisting interface");
		return;
	}

	mutex_lock(&open_mutex);
	if (!usb_get_intfdata(intf)) {
		mutex_unlock(&open_mutex);
		return;
	}
	acm->dev = NULL;
	usb_set_intfdata(acm->control, NULL);
	usb_set_intfdata(acm->data, NULL);

	tasklet_disable(&acm->urb_task);

	usb_kill_urb(acm->ctrlurb);
	usb_kill_urb(acm->writeurb);
	for (i = 0; i < ACM_NRU; i++)
		usb_kill_urb(acm->ru[i].urb);

	INIT_LIST_HEAD(&acm->filled_read_bufs);
	INIT_LIST_HEAD(&acm->spare_read_bufs);

	tasklet_enable(&acm->urb_task);

	flush_scheduled_work(); /* wait for acm_softint */

	acm_write_buffers_free(acm);
	usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
	for (i = 0; i < ACM_NRB; i++)
		usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);

	usb_driver_release_interface(&acm_driver, intf == acm->control ? acm->data : intf);

	if (!acm->used) {
		acm_tty_unregister(acm);
		mutex_unlock(&open_mutex);
		return;
	}

	mutex_unlock(&open_mutex);

	if (acm->tty)
		tty_hangup(acm->tty);
}

/*
 * USB driver structure.
 */

static struct usb_device_id acm_ids[] = {
	/* quirky and broken devices */
	{ USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	/* control interfaces with various AT-command sets */
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_V25TER) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_PCCA101) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_GSM) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_3G	) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_CDMA) },

	/* NOTE:  COMM/ACM/0xff is likely MSFT RNDIS ... NOT a modem!! */
	{ }
};

MODULE_DEVICE_TABLE (usb, acm_ids);

static struct usb_driver acm_driver = {
	.name =		"cdc_acm",
	.probe =	acm_probe,
	.disconnect =	acm_disconnect,
	.id_table =	acm_ids,
};

/*
 * TTY driver structures.
 */

static struct tty_operations acm_ops = {
	.open =			acm_tty_open,
	.close =		acm_tty_close,
	.write =		acm_tty_write,
	.write_room =		acm_tty_write_room,
	.ioctl =		acm_tty_ioctl,
	.throttle =		acm_tty_throttle,
	.unthrottle =		acm_tty_unthrottle,
	.chars_in_buffer =	acm_tty_chars_in_buffer,
	.break_ctl =		acm_tty_break_ctl,
	.set_termios =		acm_tty_set_termios,
	.tiocmget =		acm_tty_tiocmget,
	.tiocmset =		acm_tty_tiocmset,
};

/*
 * Init / exit.
 */

static int __init acm_init(void)
{
	int retval;
	acm_tty_driver = alloc_tty_driver(ACM_TTY_MINORS);
	if (!acm_tty_driver)
		return -ENOMEM;
	acm_tty_driver->owner = THIS_MODULE,
	acm_tty_driver->driver_name = "acm",
	acm_tty_driver->name = "ttyACM",
	acm_tty_driver->devfs_name = "usb/acm/",
	acm_tty_driver->major = ACM_TTY_MAJOR,
	acm_tty_driver->minor_start = 0,
	acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
	acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
	acm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS,
	acm_tty_driver->init_termios = tty_std_termios;
	acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	tty_set_operations(acm_tty_driver, &acm_ops);

	retval = tty_register_driver(acm_tty_driver);
	if (retval) {
		put_tty_driver(acm_tty_driver);
		return retval;
	}

	retval = usb_register(&acm_driver);
	if (retval) {
		tty_unregister_driver(acm_tty_driver);
		put_tty_driver(acm_tty_driver);
		return retval;
	}

	info(DRIVER_VERSION ":" DRIVER_DESC);

	return 0;
}

static void __exit acm_exit(void)
{
	usb_deregister(&acm_driver);
	tty_unregister_driver(acm_tty_driver);
	put_tty_driver(acm_tty_driver);
}

module_init(acm_init);
module_exit(acm_exit);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");