uvc_driver.c

linux camera下的uvc driver驱动源码

	 */
	if ((ret = uvc_video_init(&dev->video)) < 0) {
		uvc_printk(KERN_ERR, "Failed to initialize the device "
			"(%d).\n", ret);
		return ret;
	}

	/* Register the device with V4L. */
	vdev = video_device_alloc();
	if (vdev == NULL)
		return -1;

	if (dev->udev->product != NULL)
		strncpy(vdev->name, dev->udev->product, sizeof vdev->name);
	else
		snprintf(vdev->name, sizeof vdev->name,
			"UVC Camera (%04x:%04x)",
			le16_to_cpu(dev->udev->descriptor.idVendor),
			le16_to_cpu(dev->udev->descriptor.idProduct));

	/* We already hold a reference to dev->udev. The video device will be
	 * unregistered before the reference is released, so we don't need to
	 * get another one.
	 */
	vdev->dev = &dev->intf->dev;
	vdev->type = 0;
	vdev->type2 = 0;
	vdev->minor = -1;
	vdev->fops = &uvc_fops;
	vdev->release = video_device_release;

	/* Set the driver data before calling video_register_device, otherwise
	 * uvc_v4l2_open might race us.
	 *
	 * FIXME: usb_set_intfdata hasn't been called so far. Is that a
	 * 	  problem ? Does any function which could be called here get
	 * 	  a pointer to the usb_interface ?
	 */
	dev->video.vdev = vdev;
	video_set_drvdata(vdev, &dev->video);

	if (video_register_device(vdev, VFL_TYPE_GRABBER, -1) < 0) {
		dev->video.vdev = NULL;
		video_device_release(vdev);
		return -1;
	}

	return 0;
}

/*
 * Delete the UVC device.
 *
 * Called by the kernel when the last reference to the uvc_device structure
 * is released.
 *
 * Unregistering the video devices is done here because every opened instance
 * must be closed before the device can be unregistered. An alternative would
 * have been to use another reference count for uvc_v4l2_open/uvc_release, and
 * unregister the video devices on disconnect when that reference count drops
 * to zero.
 *
 * As this function is called after or during disconnect(), all URBs have
 * already been canceled by the USB core. There is no need to kill the
 * interrupt URB manually.
 */
void uvc_delete(struct kref *kref)
{
	struct uvc_device *dev = container_of(kref, struct uvc_device, kref);
	struct list_head *p, *n;

	/* Unregister the video device */
	uvc_unregister_video(dev);
	usb_put_intf(dev->intf);
	usb_put_dev(dev->udev);

	uvc_status_cleanup(dev);
	uvc_ctrl_cleanup_device(dev);

	list_for_each_safe(p, n, &dev->entities) {
		struct uvc_entity *entity;
		entity = list_entry(p, struct uvc_entity, list);
		kfree(entity);
	}

	list_for_each_safe(p, n, &dev->streaming) {
		struct uvc_streaming *streaming;
		streaming = list_entry(p, struct uvc_streaming, list);
		usb_put_intf(streaming->intf);
		kfree(streaming->format);
		kfree(streaming->header.bmaControls);
		kfree(streaming);
	}

	kfree(dev);
}

static int uvc_probe(struct usb_interface *intf,
		     const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(intf);
	struct uvc_device *dev;
	int ret;

	if (id->idVendor && id->idProduct)
		uvc_trace(UVC_TRACE_PROBE, "Probing known UVC device %s "
				"(%04x:%04x)\n", udev->devpath, id->idVendor,
				id->idProduct);
	else
		uvc_trace(UVC_TRACE_PROBE, "Probing generic UVC device %s\n",
				udev->devpath);

	/* Allocate memory for the device and initialize it */
	if ((dev = kzalloc(sizeof *dev, GFP_KERNEL)) == NULL)
		return -ENOMEM;

	INIT_LIST_HEAD(&dev->entities);
	INIT_LIST_HEAD(&dev->streaming);
	kref_init(&dev->kref);

	dev->udev = usb_get_dev(udev);
	dev->intf = usb_get_intf(intf);
	dev->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
	dev->quirks = id->driver_info | uvc_quirks_param;

	/* Parse the Video Class control descriptor */
	if (uvc_parse_control(dev) < 0) {
		uvc_trace(UVC_TRACE_PROBE, "Unable to parse UVC descriptors.\n");
		goto error;
	}

	uvc_printk(KERN_INFO, "Found UVC %u.%02u device %s (%04x:%04x)\n",
		dev->uvc_version >> 8, dev->uvc_version & 0xff,
		udev->product ? udev->product : "<unnamed>",
		le16_to_cpu(udev->descriptor.idVendor),
		le16_to_cpu(udev->descriptor.idProduct));

	if (uvc_quirks_param != 0) {
		uvc_printk(KERN_INFO, "Forcing device quirks 0x%x by module "
			"parameter for testing purpose.\n", uvc_quirks_param);
		uvc_printk(KERN_INFO, "Please report required quirks to the "
			"linux-uvc-devel mailing list.\n");
	}

	/* Initialize controls */
	if (uvc_ctrl_init_device(dev) < 0)
		goto error;

	/* Register the video devices */
	if (uvc_register_video(dev) < 0)
		goto error;

	/* Save our data pointer in the interface data */
	usb_set_intfdata(intf, dev);

	/* Initialize the interrupt URB */
	if ((ret = uvc_status_init(dev)) < 0) {
		uvc_printk(KERN_INFO, "Unable to initialize the status "
			"endpoint (%d), status interrupt will not be "
			"supported.\n", ret);
	}

	uvc_trace(UVC_TRACE_PROBE, "UVC device initialized.\n");
	return 0;

error:
	kref_put(&dev->kref, uvc_delete);
	return -ENODEV;
}

static void uvc_disconnect(struct usb_interface *intf)
{
	struct uvc_device *dev = usb_get_intfdata(intf);

	/* Set the USB interface data to NULL. This can be done outside the
	 * lock, as there's no other reader.
	 */
	usb_set_intfdata(intf, NULL);

	if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOSTREAMING)
		return;

	/* uvc_v4l2_open() might race uvc_disconnect(). A static driver-wide
	 * lock is needed to prevent uvc_disconnect from releasing its
	 * reference to the uvc_device instance after uvc_v4l2_open() received
	 * the pointer to the device (video_devdata) but before it got the
	 * chance to increase the reference count (kref_get). An alternative
	 * (used by the usb-skeleton driver) would have been to use the big
	 * kernel lock instead of a driver-specific mutex (open calls on
	 * char devices are protected by the BKL), but that approach is not
	 * recommended for new code.
	 */
	mutex_lock(&uvc_driver.open_mutex);

	dev->state |= UVC_DEV_DISCONNECTED;
	kref_put(&dev->kref, uvc_delete);

	mutex_unlock(&uvc_driver.open_mutex);
}

static int uvc_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct uvc_device *dev = usb_get_intfdata(intf);

	uvc_trace(UVC_TRACE_SUSPEND, "Suspending interface %u\n",
		intf->cur_altsetting->desc.bInterfaceNumber);

	/* Controls are cached on the fly so they don't need to be saved. */
	if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOCONTROL)
		return uvc_status_suspend(dev);

	if (dev->video.streaming->intf != intf) {
		uvc_trace(UVC_TRACE_SUSPEND, "Suspend: video streaming USB "
				"interface mismatch.\n");
		return -EINVAL;
	}

	return uvc_video_suspend(&dev->video);
}

static int uvc_resume(struct usb_interface *intf)
{
	struct uvc_device *dev = usb_get_intfdata(intf);
	int ret;

	uvc_trace(UVC_TRACE_SUSPEND, "Resuming interface %u\n",
		intf->cur_altsetting->desc.bInterfaceNumber);

	if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOCONTROL) {
		if ((ret = uvc_ctrl_resume_device(dev)) < 0)
			return ret;

		return uvc_status_resume(dev);
	}

	if (dev->video.streaming->intf != intf) {
		uvc_trace(UVC_TRACE_SUSPEND, "Resume: video streaming USB "
				"interface mismatch.\n");
		return -EINVAL;
	}

	return uvc_video_resume(&dev->video);
}

/* ------------------------------------------------------------------------
 * Driver initialization and cleanup
 */

/*
 * The Logitech cameras listed below have their interface class set to
 * VENDOR_SPEC because they don't announce themselves as UVC devices, even
 * though they are compliant.
 */
static struct usb_device_id uvc_ids[] = {
	/* ALi M5606 (Clevo M540SR) */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x0402,
	  .idProduct		= 0x5606,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
	/* Creative Live! Optia */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x041e,
	  .idProduct		= 0x4057,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
	/* Microsoft Lifecam NX-6000 */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x045e,
	  .idProduct		= 0x00f8,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
	/* Logitech Quickcam Fusion */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x046d,
	  .idProduct		= 0x08c1,
	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0 },
	/* Logitech Quickcam Orbit MP */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x046d,
	  .idProduct		= 0x08c2,
	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0 },
	/* Logitech Quickcam Pro for Notebook */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x046d,
	  .idProduct		= 0x08c3,
	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0 },
	/* Logitech Quickcam Pro 5000 */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x046d,
	  .idProduct		= 0x08c5,
	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0 },
	/* Logitech Quickcam OEM Dell Notebook */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x046d,
	  .idProduct		= 0x08c6,
	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0 },
	/* Logitech Quickcam OEM Cisco VT Camera II */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x046d,
	  .idProduct		= 0x08c7,
	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0 },
	/* Apple Built-In iSight */
	{ .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x05ac,
	  .idProduct		= 0x8501,
	  .bInterfaceClass      = USB_CLASS_VIDEO,
	  .bInterfaceSubClass   = 1,
	  .bInterfaceProtocol   = 0,
	  .driver_info 		= UVC_QUIRK_PROBE_MINMAX
	                        | UVC_QUIRK_BUILTIN_ISIGHT },
	/* Genesys Logic USB 2.0 PC Camera */
	{ .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor             = 0x05e3,
	  .idProduct            = 0x0505,
	  .bInterfaceClass      = USB_CLASS_VIDEO,
	  .bInterfaceSubClass   = 1,
	  .bInterfaceProtocol   = 0,
	  .driver_info          = UVC_QUIRK_STREAM_NO_FID },
	/* Silicon Motion SM371 */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x090c,
	  .idProduct		= 0xb371,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
 	/* MT6227 */
 	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
 				| USB_DEVICE_ID_MATCH_INT_INFO,
 	  .idVendor		= 0x0e8d,
 	  .idProduct		= 0x0004,
 	  .bInterfaceClass	= USB_CLASS_VIDEO,
 	  .bInterfaceSubClass	= 1,
 	  .bInterfaceProtocol	= 0,
 	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
	/* Syntek (HP Spartan) */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x174f,
	  .idProduct		= 0x5212,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
	/* Ecamm Pico iMage */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x18cd,
	  .idProduct		= 0xcafe,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_PROBE_EXTRAFIELDS },
	/* Bodelin ProScopeHR */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x19ab,
	  .idProduct		= 0x1000,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_STATUS_INTERVAL },
	/* Acer OEM Webcam - Unknown vendor */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x5986,
	  .idProduct		= 0x0100,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
	/* Acer Crystal Eye webcam */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x5986,
	  .idProduct		= 0x0102,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
	/* Acer OrbiCam - Unknown vendor */
	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
				| USB_DEVICE_ID_MATCH_INT_INFO,
	  .idVendor		= 0x5986,
	  .idProduct		= 0x0200,
	  .bInterfaceClass	= USB_CLASS_VIDEO,
	  .bInterfaceSubClass	= 1,
	  .bInterfaceProtocol	= 0,
	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
	/* Generic USB Video Class */
	{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, 0) },
	{}
};

MODULE_DEVICE_TABLE(usb, uvc_ids);

struct uvc_driver uvc_driver = {
	.driver = {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,16)
		.owner		= THIS_MODULE,
#endif
		.name		= "uvcvideo",
		.probe		= uvc_probe,
		.disconnect	= uvc_disconnect,
		.suspend	= uvc_suspend,
		.resume		= uvc_resume,
		.id_table	= uvc_ids,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19)
		.supports_autosuspend = 1,
#endif
	},
};

static int __init uvc_init(void)
{
	int result;

	INIT_LIST_HEAD(&uvc_driver.devices);
	INIT_LIST_HEAD(&uvc_driver.controls);
	mutex_init(&uvc_driver.open_mutex);
	mutex_init(&uvc_driver.ctrl_mutex);

	uvc_ctrl_init();

	result = usb_register(&uvc_driver.driver);
	if (result == 0)
		printk(KERN_INFO DRIVER_DESC " (" DRIVER_VERSION ")\n");
	return result;
}

static void __exit uvc_cleanup(void)
{
	usb_deregister(&uvc_driver.driver);
}

module_init(uvc_init);
module_exit(uvc_cleanup);

module_param_named(quirks, uvc_quirks_param, uint, S_IRUGO|S_IWUSR);
module_param_named(trace, uvc_trace_param, uint, S_IRUGO|S_IWUSR);

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