Merge tag 'uvcg-20180925' of git://linuxtv.org/pinchartl/media into testing/next

UVC gadget updates for v4.20

- configfs cleanups, fixes and extensions
- Endianness fixes
- Miscellaneous cleanups

7 files changed, 740 insertions, 558 deletions

diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index d8ce7868fe22..8c99392df593 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -197,12 +197,6 @@ static const struct usb_descriptor_header * const uvc_ss_streaming[] = {
 	NULL,
 };
 
-void uvc_set_trace_param(unsigned int trace)
-{
-	uvc_gadget_trace_param = trace;
-}
-EXPORT_SYMBOL(uvc_set_trace_param);
-
 /* --------------------------------------------------------------------------
  * Control requests
  */
@@ -232,13 +226,8 @@ uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 	struct v4l2_event v4l2_event;
 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
 
-	/* printk(KERN_INFO "setup request %02x %02x value %04x index %04x %04x\n",
-	 *	ctrl->bRequestType, ctrl->bRequest, le16_to_cpu(ctrl->wValue),
-	 *	le16_to_cpu(ctrl->wIndex), le16_to_cpu(ctrl->wLength));
-	 */
-
 	if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS) {
-		INFO(f->config->cdev, "invalid request type\n");
+		uvcg_info(f, "invalid request type\n");
 		return -EINVAL;
 	}
 
@@ -272,7 +261,7 @@ uvc_function_get_alt(struct usb_function *f, unsigned interface)
 {
 	struct uvc_device *uvc = to_uvc(f);
 
-	INFO(f->config->cdev, "uvc_function_get_alt(%u)\n", interface);
+	uvcg_info(f, "%s(%u)\n", __func__, interface);
 
 	if (interface == uvc->control_intf)
 		return 0;
@@ -291,13 +280,13 @@ uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
 	int ret;
 
-	INFO(cdev, "uvc_function_set_alt(%u, %u)\n", interface, alt);
+	uvcg_info(f, "%s(%u, %u)\n", __func__, interface, alt);
 
 	if (interface == uvc->control_intf) {
 		if (alt)
 			return -EINVAL;
 
-		INFO(cdev, "reset UVC Control\n");
+		uvcg_info(f, "reset UVC Control\n");
 		usb_ep_disable(uvc->control_ep);
 
 		if (!uvc->control_ep->desc)
@@ -348,7 +337,7 @@ uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
 		if (!uvc->video.ep)
 			return -EINVAL;
 
-		INFO(cdev, "reset UVC\n");
+		uvcg_info(f, "reset UVC\n");
 		usb_ep_disable(uvc->video.ep);
 
 		ret = config_ep_by_speed(f->config->cdev->gadget,
@@ -373,7 +362,7 @@ uvc_function_disable(struct usb_function *f)
 	struct uvc_device *uvc = to_uvc(f);
 	struct v4l2_event v4l2_event;
 
-	INFO(f->config->cdev, "uvc_function_disable\n");
+	uvcg_info(f, "%s()\n", __func__);
 
 	memset(&v4l2_event, 0, sizeof(v4l2_event));
 	v4l2_event.type = UVC_EVENT_DISCONNECT;
@@ -392,21 +381,19 @@ uvc_function_disable(struct usb_function *f)
 void
 uvc_function_connect(struct uvc_device *uvc)
 {
-	struct usb_composite_dev *cdev = uvc->func.config->cdev;
 	int ret;
 
 	if ((ret = usb_function_activate(&uvc->func)) < 0)
-		INFO(cdev, "UVC connect failed with %d\n", ret);
+		uvcg_info(&uvc->func, "UVC connect failed with %d\n", ret);
 }
 
 void
 uvc_function_disconnect(struct uvc_device *uvc)
 {
-	struct usb_composite_dev *cdev = uvc->func.config->cdev;
 	int ret;
 
 	if ((ret = usb_function_deactivate(&uvc->func)) < 0)
-		INFO(cdev, "UVC disconnect failed with %d\n", ret);
+		uvcg_info(&uvc->func, "UVC disconnect failed with %d\n", ret);
 }
 
 /* --------------------------------------------------------------------------
@@ -605,7 +592,7 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	struct f_uvc_opts *opts;
 	int ret = -EINVAL;
 
-	INFO(cdev, "uvc_function_bind\n");
+	uvcg_info(f, "%s()\n", __func__);
 
 	opts = fi_to_f_uvc_opts(f->fi);
 	/* Sanity check the streaming endpoint module parameters.
@@ -618,8 +605,8 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	if (opts->streaming_maxburst &&
 	    (opts->streaming_maxpacket % 1024) != 0) {
 		opts->streaming_maxpacket = roundup(opts->streaming_maxpacket, 1024);
-		INFO(cdev, "overriding streaming_maxpacket to %d\n",
-		     opts->streaming_maxpacket);
+		uvcg_info(f, "overriding streaming_maxpacket to %d\n",
+			  opts->streaming_maxpacket);
 	}
 
 	/* Fill in the FS/HS/SS Video Streaming specific descriptors from the
@@ -658,7 +645,7 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	/* Allocate endpoints. */
 	ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
 	if (!ep) {
-		INFO(cdev, "Unable to allocate control EP\n");
+		uvcg_info(f, "Unable to allocate control EP\n");
 		goto error;
 	}
 	uvc->control_ep = ep;
@@ -672,7 +659,7 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);
 
 	if (!ep) {
-		INFO(cdev, "Unable to allocate streaming EP\n");
+		uvcg_info(f, "Unable to allocate streaming EP\n");
 		goto error;
 	}
 	uvc->video.ep = ep;
@@ -699,12 +686,14 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	uvc_iad.bFirstInterface = ret;
 	uvc_control_intf.bInterfaceNumber = ret;
 	uvc->control_intf = ret;
+	opts->control_interface = ret;
 
 	if ((ret = usb_interface_id(c, f)) < 0)
 		goto error;
 	uvc_streaming_intf_alt0.bInterfaceNumber = ret;
 	uvc_streaming_intf_alt1.bInterfaceNumber = ret;
 	uvc->streaming_intf = ret;
+	opts->streaming_interface = ret;
 
 	/* Copy descriptors */
 	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
@@ -743,19 +732,19 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	uvc->control_req->context = uvc;
 
 	if (v4l2_device_register(&cdev->gadget->dev, &uvc->v4l2_dev)) {
-		printk(KERN_INFO "v4l2_device_register failed\n");
+		uvcg_err(f, "failed to register V4L2 device\n");
 		goto error;
 	}
 
 	/* Initialise video. */
-	ret = uvcg_video_init(&uvc->video);
+	ret = uvcg_video_init(&uvc->video, uvc);
 	if (ret < 0)
 		goto error;
 
 	/* Register a V4L2 device. */
 	ret = uvc_register_video(uvc);
 	if (ret < 0) {
-		printk(KERN_INFO "Unable to register video device\n");
+		uvcg_err(f, "failed to register video device\n");
 		goto error;
 	}
 
@@ -792,6 +781,7 @@ static struct usb_function_instance *uvc_alloc_inst(void)
 	struct uvc_output_terminal_descriptor *od;
 	struct uvc_color_matching_descriptor *md;
 	struct uvc_descriptor_header **ctl_cls;
+	int ret;
 
 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 	if (!opts)
@@ -868,7 +858,12 @@ static struct usb_function_instance *uvc_alloc_inst(void)
 	opts->streaming_interval = 1;
 	opts->streaming_maxpacket = 1024;
 
-	uvcg_attach_configfs(opts);
+	ret = uvcg_attach_configfs(opts);
+	if (ret < 0) {
+		kfree(opts);
+		return ERR_PTR(ret);
+	}
+
 	return &opts->func_inst;
 }
 
@@ -886,7 +881,7 @@ static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_composite_dev *cdev = c->cdev;
 	struct uvc_device *uvc = to_uvc(f);
 
-	INFO(cdev, "%s\n", __func__);
+	uvcg_info(f, "%s\n", __func__);
 
 	device_remove_file(&uvc->vdev.dev, &dev_attr_function_name);
 	video_unregister_device(&uvc->vdev);
diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h
index 2ed292e94fbc..5242d489e20a 100644
--- a/drivers/usb/gadget/function/u_uvc.h
+++ b/drivers/usb/gadget/function/u_uvc.h
@@ -25,6 +25,9 @@ struct f_uvc_opts {
 	unsigned int					streaming_maxpacket;
 	unsigned int					streaming_maxburst;
 
+	unsigned int					control_interface;
+	unsigned int					streaming_interface;
+
 	/*
 	 * Control descriptors array pointers for full-/high-speed and
 	 * super-speed. They point by default to the uvc_fs_control_cls and
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index 93cf78b420fe..099d650082e5 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -24,6 +24,7 @@
 struct usb_ep;
 struct usb_request;
 struct uvc_descriptor_header;
+struct uvc_device;
 
 /* ------------------------------------------------------------------------
  * Debugging, printing and logging
@@ -51,14 +52,12 @@ extern unsigned int uvc_gadget_trace_param;
 			printk(KERN_DEBUG "uvcvideo: " msg); \
 	} while (0)
 
-#define uvc_warn_once(dev, warn, msg...) \
-	do { \
-		if (!test_and_set_bit(warn, &dev->warnings)) \
-			printk(KERN_INFO "uvcvideo: " msg); \
-	} while (0)
-
-#define uvc_printk(level, msg...) \
-	printk(level "uvcvideo: " msg)
+#define uvcg_dbg(f, fmt, args...) \
+	dev_dbg(&(f)->config->cdev->gadget->dev, "%s: " fmt, (f)->name, ##args)
+#define uvcg_info(f, fmt, args...) \
+	dev_info(&(f)->config->cdev->gadget->dev, "%s: " fmt, (f)->name, ##args)
+#define uvcg_err(f, fmt, args...) \
+	dev_err(&(f)->config->cdev->gadget->dev, "%s: " fmt, (f)->name, ##args)
 
 /* ------------------------------------------------------------------------
  * Driver specific constants
@@ -73,6 +72,7 @@ extern unsigned int uvc_gadget_trace_param;
  */
 
 struct uvc_video {
+	struct uvc_device *uvc;
 	struct usb_ep *ep;
 
 	/* Frame parameters */
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
index b51f0d278826..bc1e2af566c3 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c
@@ -9,9 +9,16 @@
  *
  * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
  */
+
+#include <linux/sort.h>
+
 #include "u_uvc.h"
 #include "uvc_configfs.h"
 
+/* -----------------------------------------------------------------------------
+ * Global Utility Structures and Macros
+ */
+
 #define UVCG_STREAMING_CONTROL_SIZE	1
 
 #define UVC_ATTR(prefix, cname, aname) \
@@ -31,13 +38,93 @@ static struct configfs_attribute prefix##attr_##cname = { \
 	.show		= prefix##cname##_show,				\
 }
 
+#define le8_to_cpu(x)	(x)
+#define cpu_to_le8(x)	(x)
+
+static int uvcg_config_compare_u32(const void *l, const void *r)
+{
+	u32 li = *(const u32 *)l;
+	u32 ri = *(const u32 *)r;
+
+	return li < ri ? -1 : li == ri ? 0 : 1;
+}
+
 static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item)
 {
 	return container_of(to_config_group(item), struct f_uvc_opts,
 			    func_inst.group);
 }
 
-/* control/header/<NAME> */
+struct uvcg_config_group_type {
+	struct config_item_type type;
+	const char *name;
+	const struct uvcg_config_group_type **children;
+	int (*create_children)(struct config_group *group);
+};
+
+static void uvcg_config_item_release(struct config_item *item)
+{
+	struct config_group *group = to_config_group(item);
+
+	kfree(group);
+}
+
+static struct configfs_item_operations uvcg_config_item_ops = {
+	.release	= uvcg_config_item_release,
+};
+
+static int uvcg_config_create_group(struct config_group *parent,
+				    const struct uvcg_config_group_type *type);
+
+static int uvcg_config_create_children(struct config_group *group,
+				const struct uvcg_config_group_type *type)
+{
+	const struct uvcg_config_group_type **child;
+	int ret;
+
+	if (type->create_children)
+		return type->create_children(group);
+
+	for (child = type->children; child && *child; ++child) {
+		ret = uvcg_config_create_group(group, *child);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int uvcg_config_create_group(struct config_group *parent,
+				    const struct uvcg_config_group_type *type)
+{
+	struct config_group *group;
+
+	group = kzalloc(sizeof(*group), GFP_KERNEL);
+	if (!group)
+		return -ENOMEM;
+
+	config_group_init_type_name(group, type->name, &type->type);
+	configfs_add_default_group(group, parent);
+
+	return uvcg_config_create_children(group, type);
+}
+
+static void uvcg_config_remove_children(struct config_group *group)
+{
+	struct config_group *child, *n;
+
+	list_for_each_entry_safe(child, n, &group->default_groups, group_entry) {
+		list_del(&child->group_entry);
+		uvcg_config_remove_children(child);
+		config_item_put(&child->cg_item);
+	}
+}
+
+/* -----------------------------------------------------------------------------
+ * control/header/<NAME>
+ * control/header
+ */
+
 DECLARE_UVC_HEADER_DESCRIPTOR(1);
 
 struct uvcg_control_header {
@@ -51,9 +138,9 @@ static struct uvcg_control_header *to_uvcg_control_header(struct config_item *it
 	return container_of(item, struct uvcg_control_header, item);
 }
 
-#define UVCG_CTRL_HDR_ATTR(cname, aname, conv, str2u, uxx, vnoc, limit)	\
+#define UVCG_CTRL_HDR_ATTR(cname, aname, bits, limit)			\
 static ssize_t uvcg_control_header_##cname##_show(			\
-	struct config_item *item, char *page)			\
+	struct config_item *item, char *page)				\
 {									\
 	struct uvcg_control_header *ch = to_uvcg_control_header(item);	\
 	struct f_uvc_opts *opts;					\
@@ -67,7 +154,7 @@ static ssize_t uvcg_control_header_##cname##_show(			\
 	opts = to_f_uvc_opts(opts_item);				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(ch->desc.aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(ch->desc.aname));\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -83,7 +170,7 @@ uvcg_control_header_##cname##_store(struct config_item *item,		\
 	struct config_item *opts_item;					\
 	struct mutex *su_mutex = &ch->item.ci_group->cg_subsys->su_mutex;\
 	int ret;							\
-	uxx num;							\
+	u##bits num;							\
 									\
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
 									\
@@ -96,7 +183,7 @@ uvcg_control_header_##cname##_store(struct config_item *item,		\
 		goto end;						\
 	}								\
 									\
-	ret = str2u(page, 0, &num);					\
+	ret = kstrtou##bits(page, 0, &num);				\
 	if (ret)							\
 		goto end;						\
 									\
@@ -104,7 +191,7 @@ uvcg_control_header_##cname##_store(struct config_item *item,		\
 		ret = -EINVAL;						\
 		goto end;						\
 	}								\
-	ch->desc.aname = vnoc(num);					\
+	ch->desc.aname = cpu_to_le##bits(num);				\
 	ret = len;							\
 end:									\
 	mutex_unlock(&opts->lock);					\
@@ -114,11 +201,9 @@ end:									\
 									\
 UVC_ATTR(uvcg_control_header_, cname, aname)
 
-UVCG_CTRL_HDR_ATTR(bcd_uvc, bcdUVC, le16_to_cpu, kstrtou16, u16, cpu_to_le16,
-		   0xffff);
+UVCG_CTRL_HDR_ATTR(bcd_uvc, bcdUVC, 16, 0xffff);
 
-UVCG_CTRL_HDR_ATTR(dw_clock_frequency, dwClockFrequency, le32_to_cpu, kstrtou32,
-		   u32, cpu_to_le32, 0x7fffffff);
+UVCG_CTRL_HDR_ATTR(dw_clock_frequency, dwClockFrequency, 32, 0x7fffffff);
 
 #undef UVCG_CTRL_HDR_ATTR
 
@@ -129,6 +214,7 @@ static struct configfs_attribute *uvcg_control_header_attrs[] = {
 };
 
 static const struct config_item_type uvcg_control_header_type = {
+	.ct_item_ops	= &uvcg_config_item_ops,
 	.ct_attrs	= uvcg_control_header_attrs,
 	.ct_owner	= THIS_MODULE,
 };
@@ -153,60 +239,42 @@ static struct config_item *uvcg_control_header_make(struct config_group *group,
 	return &h->item;
 }
 
-static void uvcg_control_header_drop(struct config_group *group,
-			      struct config_item *item)
-{
-	struct uvcg_control_header *h = to_uvcg_control_header(item);
-
-	kfree(h);
-}
-
-/* control/header */
-static struct uvcg_control_header_grp {
-	struct config_group	group;
-} uvcg_control_header_grp;
-
 static struct configfs_group_operations uvcg_control_header_grp_ops = {
 	.make_item		= uvcg_control_header_make,
-	.drop_item		= uvcg_control_header_drop,
 };
 
-static const struct config_item_type uvcg_control_header_grp_type = {
-	.ct_group_ops	= &uvcg_control_header_grp_ops,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_control_header_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_group_ops	= &uvcg_control_header_grp_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "header",
 };
 
-/* control/processing/default */
-static struct uvcg_default_processing {
-	struct config_group	group;
-} uvcg_default_processing;
-
-static inline struct uvcg_default_processing
-*to_uvcg_default_processing(struct config_item *item)
-{
-	return container_of(to_config_group(item),
-			    struct uvcg_default_processing, group);
-}
+/* -----------------------------------------------------------------------------
+ * control/processing/default
+ */
 
-#define UVCG_DEFAULT_PROCESSING_ATTR(cname, aname, conv)		\
+#define UVCG_DEFAULT_PROCESSING_ATTR(cname, aname, bits)		\
 static ssize_t uvcg_default_processing_##cname##_show(			\
 	struct config_item *item, char *page)				\
 {									\
-	struct uvcg_default_processing *dp = to_uvcg_default_processing(item); \
+	struct config_group *group = to_config_group(item);		\
 	struct f_uvc_opts *opts;					\
 	struct config_item *opts_item;					\
-	struct mutex *su_mutex = &dp->group.cg_subsys->su_mutex;	\
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;		\
 	struct uvc_processing_unit_descriptor *pd;			\
 	int result;							\
 									\
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
 									\
-	opts_item = dp->group.cg_item.ci_parent->ci_parent->ci_parent;	\
+	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;	\
 	opts = to_f_uvc_opts(opts_item);				\
 	pd = &opts->uvc_processing;					\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(pd->aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(pd->aname));	\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -215,37 +283,33 @@ static ssize_t uvcg_default_processing_##cname##_show(			\
 									\
 UVC_ATTR_RO(uvcg_default_processing_, cname, aname)
 
-#define identity_conv(x) (x)
-
-UVCG_DEFAULT_PROCESSING_ATTR(b_unit_id, bUnitID, identity_conv);
-UVCG_DEFAULT_PROCESSING_ATTR(b_source_id, bSourceID, identity_conv);
-UVCG_DEFAULT_PROCESSING_ATTR(w_max_multiplier, wMaxMultiplier, le16_to_cpu);
-UVCG_DEFAULT_PROCESSING_ATTR(i_processing, iProcessing, identity_conv);
-
-#undef identity_conv
+UVCG_DEFAULT_PROCESSING_ATTR(b_unit_id, bUnitID, 8);
+UVCG_DEFAULT_PROCESSING_ATTR(b_source_id, bSourceID, 8);
+UVCG_DEFAULT_PROCESSING_ATTR(w_max_multiplier, wMaxMultiplier, 16);
+UVCG_DEFAULT_PROCESSING_ATTR(i_processing, iProcessing, 8);
 
 #undef UVCG_DEFAULT_PROCESSING_ATTR
 
 static ssize_t uvcg_default_processing_bm_controls_show(
 	struct config_item *item, char *page)
 {
-	struct uvcg_default_processing *dp = to_uvcg_default_processing(item);
+	struct config_group *group = to_config_group(item);
 	struct f_uvc_opts *opts;
 	struct config_item *opts_item;
-	struct mutex *su_mutex = &dp->group.cg_subsys->su_mutex;
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
 	struct uvc_processing_unit_descriptor *pd;
 	int result, i;
 	char *pg = page;
 
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
 
-	opts_item = dp->group.cg_item.ci_parent->ci_parent->ci_parent;
+	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;
 	opts = to_f_uvc_opts(opts_item);
 	pd = &opts->uvc_processing;
 
 	mutex_lock(&opts->lock);
 	for (result = 0, i = 0; i < pd->bControlSize; ++i) {
-		result += sprintf(pg, "%d\n", pd->bmControls[i]);
+		result += sprintf(pg, "%u\n", pd->bmControls[i]);
 		pg = page + result;
 	}
 	mutex_unlock(&opts->lock);
@@ -266,54 +330,55 @@ static struct configfs_attribute *uvcg_default_processing_attrs[] = {
 	NULL,
 };
 
-static const struct config_item_type uvcg_default_processing_type = {
-	.ct_attrs	= uvcg_default_processing_attrs,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_default_processing_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_attrs	= uvcg_default_processing_attrs,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "default",
 };
 
-/* struct uvcg_processing {}; */
-
-/* control/processing */
-static struct uvcg_processing_grp {
-	struct config_group	group;
-} uvcg_processing_grp;
+/* -----------------------------------------------------------------------------
+ * control/processing
+ */
 
-static const struct config_item_type uvcg_processing_grp_type = {
-	.ct_owner = THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_processing_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "processing",
+	.children = (const struct uvcg_config_group_type*[]) {
+		&uvcg_default_processing_type,
+		NULL,
+	},
 };
 
-/* control/terminal/camera/default */
-static struct uvcg_default_camera {
-	struct config_group	group;
-} uvcg_default_camera;
-
-static inline struct uvcg_default_camera
-*to_uvcg_default_camera(struct config_item *item)
-{
-	return container_of(to_config_group(item),
-			    struct uvcg_default_camera, group);
-}
+/* -----------------------------------------------------------------------------
+ * control/terminal/camera/default
+ */
 
-#define UVCG_DEFAULT_CAMERA_ATTR(cname, aname, conv)			\
+#define UVCG_DEFAULT_CAMERA_ATTR(cname, aname, bits)			\
 static ssize_t uvcg_default_camera_##cname##_show(			\
 	struct config_item *item, char *page)				\
 {									\
-	struct uvcg_default_camera *dc = to_uvcg_default_camera(item);	\
+	struct config_group *group = to_config_group(item);		\
 	struct f_uvc_opts *opts;					\
 	struct config_item *opts_item;					\
-	struct mutex *su_mutex = &dc->group.cg_subsys->su_mutex;	\
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;		\
 	struct uvc_camera_terminal_descriptor *cd;			\
 	int result;							\
 									\
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
 									\
-	opts_item = dc->group.cg_item.ci_parent->ci_parent->ci_parent->	\
+	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent->	\
 			ci_parent;					\
 	opts = to_f_uvc_opts(opts_item);				\
 	cd = &opts->uvc_camera_terminal;				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(cd->aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(cd->aname));	\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -323,44 +388,40 @@ static ssize_t uvcg_default_camera_##cname##_show(			\
 									\
 UVC_ATTR_RO(uvcg_default_camera_, cname, aname)
 
-#define identity_conv(x) (x)
-
-UVCG_DEFAULT_CAMERA_ATTR(b_terminal_id, bTerminalID, identity_conv);
-UVCG_DEFAULT_CAMERA_ATTR(w_terminal_type, wTerminalType, le16_to_cpu);
-UVCG_DEFAULT_CAMERA_ATTR(b_assoc_terminal, bAssocTerminal, identity_conv);
-UVCG_DEFAULT_CAMERA_ATTR(i_terminal, iTerminal, identity_conv);
+UVCG_DEFAULT_CAMERA_ATTR(b_terminal_id, bTerminalID, 8);
+UVCG_DEFAULT_CAMERA_ATTR(w_terminal_type, wTerminalType, 16);
+UVCG_DEFAULT_CAMERA_ATTR(b_assoc_terminal, bAssocTerminal, 8);
+UVCG_DEFAULT_CAMERA_ATTR(i_terminal, iTerminal, 8);
 UVCG_DEFAULT_CAMERA_ATTR(w_objective_focal_length_min, wObjectiveFocalLengthMin,
-			 le16_to_cpu);
+			 16);
 UVCG_DEFAULT_CAMERA_ATTR(w_objective_focal_length_max, wObjectiveFocalLengthMax,
-			 le16_to_cpu);
+			 16);
 UVCG_DEFAULT_CAMERA_ATTR(w_ocular_focal_length, wOcularFocalLength,
-			 le16_to_cpu);
-
-#undef identity_conv
+			 16);
 
 #undef UVCG_DEFAULT_CAMERA_ATTR
 
 static ssize_t uvcg_default_camera_bm_controls_show(
 	struct config_item *item, char *page)
 {
-	struct uvcg_default_camera *dc = to_uvcg_default_camera(item);
+	struct config_group *group = to_config_group(item);
 	struct f_uvc_opts *opts;
 	struct config_item *opts_item;
-	struct mutex *su_mutex = &dc->group.cg_subsys->su_mutex;
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
 	struct uvc_camera_terminal_descriptor *cd;
 	int result, i;
 	char *pg = page;
 
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
 
-	opts_item = dc->group.cg_item.ci_parent->ci_parent->ci_parent->
+	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent->
 			ci_parent;
 	opts = to_f_uvc_opts(opts_item);
 	cd = &opts->uvc_camera_terminal;
 
 	mutex_lock(&opts->lock);
 	for (result = 0, i = 0; i < cd->bControlSize; ++i) {
-		result += sprintf(pg, "%d\n", cd->bmControls[i]);
+		result += sprintf(pg, "%u\n", cd->bmControls[i]);
 		pg = page + result;
 	}
 	mutex_unlock(&opts->lock);
@@ -383,54 +444,55 @@ static struct configfs_attribute *uvcg_default_camera_attrs[] = {
 	NULL,
 };
 
-static const struct config_item_type uvcg_default_camera_type = {
-	.ct_attrs	= uvcg_default_camera_attrs,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_default_camera_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_attrs	= uvcg_default_camera_attrs,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "default",
 };
 
-/* struct uvcg_camera {}; */
-
-/* control/terminal/camera */
-static struct uvcg_camera_grp {
-	struct config_group	group;
-} uvcg_camera_grp;
+/* -----------------------------------------------------------------------------
+ * control/terminal/camera
+ */
 
-static const struct config_item_type uvcg_camera_grp_type = {
-	.ct_owner = THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_camera_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "camera",
+	.children = (const struct uvcg_config_group_type*[]) {
+		&uvcg_default_camera_type,
+		NULL,
+	},
 };
 
-/* control/terminal/output/default */
-static struct uvcg_default_output {
-	struct config_group	group;
-} uvcg_default_output;
-
-static inline struct uvcg_default_output
-*to_uvcg_default_output(struct config_item *item)
-{
-	return container_of(to_config_group(item),
-			    struct uvcg_default_output, group);
-}
+/* -----------------------------------------------------------------------------
+ * control/terminal/output/default
+ */
 
-#define UVCG_DEFAULT_OUTPUT_ATTR(cname, aname, conv)			\
+#define UVCG_DEFAULT_OUTPUT_ATTR(cname, aname, bits)			\
 static ssize_t uvcg_default_output_##cname##_show(			\
-	struct config_item *item, char *page)			\
+	struct config_item *item, char *page)				\
 {									\
-	struct uvcg_default_output *dout = to_uvcg_default_output(item); \
+	struct config_group *group = to_config_group(item);		\
 	struct f_uvc_opts *opts;					\
 	struct config_item *opts_item;					\
-	struct mutex *su_mutex = &dout->group.cg_subsys->su_mutex;	\
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;		\
 	struct uvc_output_terminal_descriptor *cd;			\
 	int result;							\
 									\
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
 									\
-	opts_item = dout->group.cg_item.ci_parent->ci_parent->		\
+	opts_item = group->cg_item.ci_parent->ci_parent->		\
 			ci_parent->ci_parent;				\
 	opts = to_f_uvc_opts(opts_item);				\
 	cd = &opts->uvc_output_terminal;				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(cd->aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(cd->aname));	\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -440,15 +502,11 @@ static ssize_t uvcg_default_output_##cname##_show(			\
 									\
 UVC_ATTR_RO(uvcg_default_output_, cname, aname)
 
-#define identity_conv(x) (x)
-
-UVCG_DEFAULT_OUTPUT_ATTR(b_terminal_id, bTerminalID, identity_conv);
-UVCG_DEFAULT_OUTPUT_ATTR(w_terminal_type, wTerminalType, le16_to_cpu);
-UVCG_DEFAULT_OUTPUT_ATTR(b_assoc_terminal, bAssocTerminal, identity_conv);
-UVCG_DEFAULT_OUTPUT_ATTR(b_source_id, bSourceID, identity_conv);
-UVCG_DEFAULT_OUTPUT_ATTR(i_terminal, iTerminal, identity_conv);
-
-#undef identity_conv
+UVCG_DEFAULT_OUTPUT_ATTR(b_terminal_id, bTerminalID, 8);
+UVCG_DEFAULT_OUTPUT_ATTR(w_terminal_type, wTerminalType, 16);
+UVCG_DEFAULT_OUTPUT_ATTR(b_assoc_terminal, bAssocTerminal, 8);
+UVCG_DEFAULT_OUTPUT_ATTR(b_source_id, bSourceID, 8);
+UVCG_DEFAULT_OUTPUT_ATTR(i_terminal, iTerminal, 8);
 
 #undef UVCG_DEFAULT_OUTPUT_ATTR
 
@@ -461,47 +519,68 @@ static struct configfs_attribute *uvcg_default_output_attrs[] = {
 	NULL,
 };
 
-static const struct config_item_type uvcg_default_output_type = {
-	.ct_attrs	= uvcg_default_output_attrs,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_default_output_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_attrs	= uvcg_default_output_attrs,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "default",
 };
 
-/* struct uvcg_output {}; */
-
-/* control/terminal/output */
-static struct uvcg_output_grp {
-	struct config_group	group;
-} uvcg_output_grp;
+/* -----------------------------------------------------------------------------
+ * control/terminal/output
+ */
 
-static const struct config_item_type uvcg_output_grp_type = {
-	.ct_owner = THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_output_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "output",
+	.children = (const struct uvcg_config_group_type*[]) {
+		&uvcg_default_output_type,
+		NULL,
+	},
 };
 
-/* control/terminal */
-static struct uvcg_terminal_grp {
-	struct config_group	group;
-} uvcg_terminal_grp;
+/* -----------------------------------------------------------------------------
+ * control/terminal
+ */
 
-static const struct config_item_type uvcg_terminal_grp_type = {
-	.ct_owner = THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_terminal_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "terminal",
+	.children = (const struct uvcg_config_group_type*[]) {
+		&uvcg_camera_grp_type,
+		&uvcg_output_grp_type,
+		NULL,
+	},
 };
 
-/* control/class/{fs} */
-static struct uvcg_control_class {
-	struct config_group	group;
-} uvcg_control_class_fs, uvcg_control_class_ss;
+/* -----------------------------------------------------------------------------
+ * control/class/{fs|ss}
+ */
 
+struct uvcg_control_class_group {
+	struct config_group group;
+	const char *name;
+};
 
 static inline struct uvc_descriptor_header
 **uvcg_get_ctl_class_arr(struct config_item *i, struct f_uvc_opts *o)
 {
-	struct uvcg_control_class *cl = container_of(to_config_group(i),
-		struct uvcg_control_class, group);
+	struct uvcg_control_class_group *group =
+		container_of(i, struct uvcg_control_class_group,
+			     group.cg_item);
 
-	if (cl == &uvcg_control_class_fs)
+	if (!strcmp(group->name, "fs"))
 		return o->uvc_fs_control_cls;
 
-	if (cl == &uvcg_control_class_ss)
+	if (!strcmp(group->name, "ss"))
 		return o->uvc_ss_control_cls;
 
 	return NULL;
@@ -544,6 +623,7 @@ static int uvcg_control_class_allow_link(struct config_item *src,
 unlock:
 	mutex_unlock(&opts->lock);
 out:
+	config_item_put(header);
 	mutex_unlock(su_mutex);
 	return ret;
 }
@@ -579,10 +659,12 @@ static void uvcg_control_class_drop_link(struct config_item *src,
 unlock:
 	mutex_unlock(&opts->lock);
 out:
+	config_item_put(header);
 	mutex_unlock(su_mutex);
 }
 
 static struct configfs_item_operations uvcg_control_class_item_ops = {
+	.release	= uvcg_config_item_release,
 	.allow_link	= uvcg_control_class_allow_link,
 	.drop_link	= uvcg_control_class_drop_link,
 };
@@ -592,37 +674,99 @@ static const struct config_item_type uvcg_control_class_type = {
 	.ct_owner	= THIS_MODULE,
 };
 
-/* control/class */
-static struct uvcg_control_class_grp {
-	struct config_group	group;
-} uvcg_control_class_grp;
+/* -----------------------------------------------------------------------------
+ * control/class
+ */
+
+static int uvcg_control_class_create_children(struct config_group *parent)
+{
+	static const char * const names[] = { "fs", "ss" };
+	unsigned int i;
 
-static const struct config_item_type uvcg_control_class_grp_type = {
-	.ct_owner = THIS_MODULE,
+	for (i = 0; i < ARRAY_SIZE(names); ++i) {
+		struct uvcg_control_class_group *group;
+
+		group = kzalloc(sizeof(*group), GFP_KERNEL);
+		if (!group)
+			return -ENOMEM;
+
+		group->name = names[i];
+
+		config_group_init_type_name(&group->group, group->name,
+					    &uvcg_control_class_type);
+		configfs_add_default_group(&group->group, parent);
+	}
+
+	return 0;
+}
+
+static const struct uvcg_config_group_type uvcg_control_class_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "class",
+	.create_children = uvcg_control_class_create_children,
 };
 
-/* control */
-static struct uvcg_control_grp {
-	struct config_group	group;
-} uvcg_control_grp;
+/* -----------------------------------------------------------------------------
+ * control
+ */
+
+static ssize_t uvcg_default_control_b_interface_number_show(
+	struct config_item *item, char *page)
+{
+	struct config_group *group = to_config_group(item);
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
+	struct config_item *opts_item;
+	struct f_uvc_opts *opts;
+	int result = 0;
+
+	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
+
+	opts_item = item->ci_parent;
+	opts = to_f_uvc_opts(opts_item);
+
+	mutex_lock(&opts->lock);
+	result += sprintf(page, "%u\n", opts->control_interface);
+	mutex_unlock(&opts->lock);
+
+	mutex_unlock(su_mutex);
+
+	return result;
+}
+
+UVC_ATTR_RO(uvcg_default_control_, b_interface_number, bInterfaceNumber);
 
-static const struct config_item_type uvcg_control_grp_type = {
-	.ct_owner = THIS_MODULE,
+static struct configfs_attribute *uvcg_default_control_attrs[] = {
+	&uvcg_default_control_attr_b_interface_number,
+	NULL,
 };
 
-/* streaming/uncompressed */
-static struct uvcg_uncompressed_grp {
-	struct config_group	group;
-} uvcg_uncompressed_grp;
+static const struct uvcg_config_group_type uvcg_control_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_attrs	= uvcg_default_control_attrs,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "control",
+	.children = (const struct uvcg_config_group_type*[]) {
+		&uvcg_control_header_grp_type,
+		&uvcg_processing_grp_type,
+		&uvcg_terminal_grp_type,
+		&uvcg_control_class_grp_type,
+		NULL,
+	},
+};
 
-/* streaming/mjpeg */
-static struct uvcg_mjpeg_grp {
-	struct config_group	group;
-} uvcg_mjpeg_grp;
+/* -----------------------------------------------------------------------------
+ * streaming/uncompressed
+ * streaming/mjpeg
+ */
 
-static struct config_item *fmt_parent[] = {
-	&uvcg_uncompressed_grp.group.cg_item,
-	&uvcg_mjpeg_grp.group.cg_item,
+static const char * const uvcg_format_names[] = {
+	"uncompressed",
+	"mjpeg",
 };
 
 enum uvcg_format_type {
@@ -706,7 +850,11 @@ struct uvcg_format_ptr {
 	struct list_head	entry;
 };
 
-/* streaming/header/<NAME> */
+/* -----------------------------------------------------------------------------
+ * streaming/header/<NAME>
+ * streaming/header
+ */
+
 struct uvcg_streaming_header {
 	struct config_item				item;
 	struct uvc_input_header_descriptor		desc;
@@ -720,6 +868,8 @@ static struct uvcg_streaming_header *to_uvcg_streaming_header(struct config_item
 	return container_of(item, struct uvcg_streaming_header, item);
 }
 
+static void uvcg_format_set_indices(struct config_group *fmt);
+
 static int uvcg_streaming_header_allow_link(struct config_item *src,
 					    struct config_item *target)
 {
@@ -744,10 +894,22 @@ static int uvcg_streaming_header_allow_link(struct config_item *src,
 		goto out;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(fmt_parent); ++i)
-		if (target->ci_parent == fmt_parent[i])
+	/*
+	 * Linking is only allowed to direct children of the format nodes
+	 * (streaming/uncompressed or streaming/mjpeg nodes). First check that
+	 * the grand-parent of the target matches the grand-parent of the source
+	 * (the streaming node), and then verify that the target parent is a
+	 * format node.
+	 */
+	if (src->ci_parent->ci_parent != target->ci_parent->ci_parent)
+		goto out;
+
+	for (i = 0; i < ARRAY_SIZE(uvcg_format_names); ++i) {
+		if (!strcmp(target->ci_parent->ci_name, uvcg_format_names[i]))
 			break;
-	if (i == ARRAY_SIZE(fmt_parent))
+	}
+
+	if (i == ARRAY_SIZE(uvcg_format_names))
 		goto out;
 
 	target_fmt = container_of(to_config_group(target), struct uvcg_format,
@@ -755,6 +917,8 @@ static int uvcg_streaming_header_allow_link(struct config_item *src,
 	if (!target_fmt)
 		goto out;
 
+	uvcg_format_set_indices(to_config_group(target));
+
 	format_ptr = kzalloc(sizeof(*format_ptr), GFP_KERNEL);
 	if (!format_ptr) {
 		ret = -ENOMEM;
@@ -764,6 +928,7 @@ static int uvcg_streaming_header_allow_link(struct config_item *src,
 	format_ptr->fmt = target_fmt;
 	list_add_tail(&format_ptr->entry, &src_hdr->formats);
 	++src_hdr->num_fmt;
+	++target_fmt->linked;
 
 out:
 	mutex_unlock(&opts->lock);
@@ -801,19 +966,22 @@ static void uvcg_streaming_header_drop_link(struct config_item *src,
 			break;
 		}
 
+	--target_fmt->linked;
+
 out:
 	mutex_unlock(&opts->lock);
 	mutex_unlock(su_mutex);
 }
 
 static struct configfs_item_operations uvcg_streaming_header_item_ops = {
-	.allow_link		= uvcg_streaming_header_allow_link,
-	.drop_link		= uvcg_streaming_header_drop_link,
+	.release	= uvcg_config_item_release,
+	.allow_link	= uvcg_streaming_header_allow_link,
+	.drop_link	= uvcg_streaming_header_drop_link,
 };
 
-#define UVCG_STREAMING_HEADER_ATTR(cname, aname, conv)			\
+#define UVCG_STREAMING_HEADER_ATTR(cname, aname, bits)			\
 static ssize_t uvcg_streaming_header_##cname##_show(			\
-	struct config_item *item, char *page)			\
+	struct config_item *item, char *page)				\
 {									\
 	struct uvcg_streaming_header *sh = to_uvcg_streaming_header(item); \
 	struct f_uvc_opts *opts;					\
@@ -827,7 +995,7 @@ static ssize_t uvcg_streaming_header_##cname##_show(			\
 	opts = to_f_uvc_opts(opts_item);				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(sh->desc.aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(sh->desc.aname));\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -836,16 +1004,11 @@ static ssize_t uvcg_streaming_header_##cname##_show(			\
 									\
 UVC_ATTR_RO(uvcg_streaming_header_, cname, aname)
 
-#define identity_conv(x) (x)
-
-UVCG_STREAMING_HEADER_ATTR(bm_info, bmInfo, identity_conv);
-UVCG_STREAMING_HEADER_ATTR(b_terminal_link, bTerminalLink, identity_conv);
-UVCG_STREAMING_HEADER_ATTR(b_still_capture_method, bStillCaptureMethod,
-			   identity_conv);
-UVCG_STREAMING_HEADER_ATTR(b_trigger_support, bTriggerSupport, identity_conv);
-UVCG_STREAMING_HEADER_ATTR(b_trigger_usage, bTriggerUsage, identity_conv);
-
-#undef identity_conv
+UVCG_STREAMING_HEADER_ATTR(bm_info, bmInfo, 8);
+UVCG_STREAMING_HEADER_ATTR(b_terminal_link, bTerminalLink, 8);
+UVCG_STREAMING_HEADER_ATTR(b_still_capture_method, bStillCaptureMethod, 8);
+UVCG_STREAMING_HEADER_ATTR(b_trigger_support, bTriggerSupport, 8);
+UVCG_STREAMING_HEADER_ATTR(b_trigger_usage, bTriggerUsage, 8);
 
 #undef UVCG_STREAMING_HEADER_ATTR
 
@@ -884,31 +1047,26 @@ static struct config_item
 	return &h->item;
 }
 
-static void uvcg_streaming_header_drop(struct config_group *group,
-			      struct config_item *item)
-{
-	struct uvcg_streaming_header *h = to_uvcg_streaming_header(item);
-
-	kfree(h);
-}
-
-/* streaming/header */
-static struct uvcg_streaming_header_grp {
-	struct config_group	group;
-} uvcg_streaming_header_grp;
-
 static struct configfs_group_operations uvcg_streaming_header_grp_ops = {
 	.make_item		= uvcg_streaming_header_make,
-	.drop_item		= uvcg_streaming_header_drop,
 };
 
-static const struct config_item_type uvcg_streaming_header_grp_type = {
-	.ct_group_ops	= &uvcg_streaming_header_grp_ops,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_streaming_header_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_group_ops	= &uvcg_streaming_header_grp_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "header",
 };
 
-/* streaming/<mode>/<format>/<NAME> */
+/* -----------------------------------------------------------------------------
+ * streaming/<mode>/<format>/<NAME>
+ */
+
 struct uvcg_frame {
+	struct config_item	item;
+	enum uvcg_format_type	fmt_type;
 	struct {
 		u8	b_length;
 		u8	b_descriptor_type;
@@ -924,8 +1082,6 @@ struct uvcg_frame {
 		u8	b_frame_interval_type;
 	} __attribute__((packed)) frame;
 	u32 *dw_frame_interval;
-	enum uvcg_format_type	fmt_type;
-	struct config_item	item;
 };
 
 static struct uvcg_frame *to_uvcg_frame(struct config_item *item)
@@ -933,7 +1089,7 @@ static struct uvcg_frame *to_uvcg_frame(struct config_item *item)
 	return container_of(item, struct uvcg_frame, item);
 }
 
-#define UVCG_FRAME_ATTR(cname, aname, to_cpu_endian, to_little_endian, bits) \
+#define UVCG_FRAME_ATTR(cname, aname, bits) \
 static ssize_t uvcg_frame_##cname##_show(struct config_item *item, char *page)\
 {									\
 	struct uvcg_frame *f = to_uvcg_frame(item);			\
@@ -948,7 +1104,7 @@ static ssize_t uvcg_frame_##cname##_show(struct config_item *item, char *page)\
 	opts = to_f_uvc_opts(opts_item);				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", to_cpu_endian(f->frame.cname));	\
+	result = sprintf(page, "%u\n", f->frame.cname);			\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -963,8 +1119,8 @@ static ssize_t  uvcg_frame_##cname##_store(struct config_item *item,	\
 	struct config_item *opts_item;					\
 	struct uvcg_format *fmt;					\
 	struct mutex *su_mutex = &f->item.ci_group->cg_subsys->su_mutex;\
+	typeof(f->frame.cname) num;					\
 	int ret;							\
-	u##bits num;							\
 									\
 	ret = kstrtou##bits(page, 0, &num);				\
 	if (ret)							\
@@ -982,7 +1138,7 @@ static ssize_t  uvcg_frame_##cname##_store(struct config_item *item,	\
 		goto end;						\
 	}								\
 									\
-	f->frame.cname = to_little_endian(num);				\
+	f->frame.cname = num;						\
 	ret = len;							\
 end:									\
 	mutex_unlock(&opts->lock);					\
@@ -992,20 +1148,48 @@ end:									\
 									\
 UVC_ATTR(uvcg_frame_, cname, aname);
 
-#define noop_conversion(x) (x)
+static ssize_t uvcg_frame_b_frame_index_show(struct config_item *item,
+					     char *page)
+{
+	struct uvcg_frame *f = to_uvcg_frame(item);
+	struct uvcg_format *fmt;
+	struct f_uvc_opts *opts;
+	struct config_item *opts_item;
+	struct config_item *fmt_item;
+	struct mutex *su_mutex = &f->item.ci_group->cg_subsys->su_mutex;
+	int result;
+
+	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
+
+	fmt_item = f->item.ci_parent;
+	fmt = to_uvcg_format(fmt_item);
 
-UVCG_FRAME_ATTR(bm_capabilities, bmCapabilities, noop_conversion,
-		noop_conversion, 8);
-UVCG_FRAME_ATTR(w_width, wWidth, le16_to_cpu, cpu_to_le16, 16);
-UVCG_FRAME_ATTR(w_height, wHeight, le16_to_cpu, cpu_to_le16, 16);
-UVCG_FRAME_ATTR(dw_min_bit_rate, dwMinBitRate, le32_to_cpu, cpu_to_le32, 32);
-UVCG_FRAME_ATTR(dw_max_bit_rate, dwMaxBitRate, le32_to_cpu, cpu_to_le32, 32);
-UVCG_FRAME_ATTR(dw_max_video_frame_buffer_size, dwMaxVideoFrameBufferSize,
-		le32_to_cpu, cpu_to_le32, 32);
-UVCG_FRAME_ATTR(dw_default_frame_interval, dwDefaultFrameInterval,
-		le32_to_cpu, cpu_to_le32, 32);
+	if (!fmt->linked) {
+		result = -EBUSY;
+		goto out;
+	}
 
-#undef noop_conversion
+	opts_item = fmt_item->ci_parent->ci_parent->ci_parent;
+	opts = to_f_uvc_opts(opts_item);
+
+	mutex_lock(&opts->lock);
+	result = sprintf(page, "%u\n", f->frame.b_frame_index);
+	mutex_unlock(&opts->lock);
+
+out:
+	mutex_unlock(su_mutex);
+	return result;
+}
+
+UVC_ATTR_RO(uvcg_frame_, b_frame_index, bFrameIndex);
+
+UVCG_FRAME_ATTR(bm_capabilities, bmCapabilities, 8);
+UVCG_FRAME_ATTR(w_width, wWidth, 16);
+UVCG_FRAME_ATTR(w_height, wHeight, 16);
+UVCG_FRAME_ATTR(dw_min_bit_rate, dwMinBitRate, 32);
+UVCG_FRAME_ATTR(dw_max_bit_rate, dwMaxBitRate, 32);
+UVCG_FRAME_ATTR(dw_max_video_frame_buffer_size, dwMaxVideoFrameBufferSize, 32);
+UVCG_FRAME_ATTR(dw_default_frame_interval, dwDefaultFrameInterval, 32);
 
 #undef UVCG_FRAME_ATTR
 
@@ -1026,8 +1210,7 @@ static ssize_t uvcg_frame_dw_frame_interval_show(struct config_item *item,
 
 	mutex_lock(&opts->lock);
 	for (result = 0, i = 0; i < frm->frame.b_frame_interval_type; ++i) {
-		result += sprintf(pg, "%d\n",
-				  le32_to_cpu(frm->dw_frame_interval[i]));
+		result += sprintf(pg, "%u\n", frm->dw_frame_interval[i]);
 		pg = page + result;
 	}
 	mutex_unlock(&opts->lock);
@@ -1052,7 +1235,7 @@ static inline int __uvcg_fill_frm_intrv(char *buf, void *priv)
 		return ret;
 
 	interv = priv;
-	**interv = cpu_to_le32(num);
+	**interv = num;
 	++*interv;
 
 	return 0;
@@ -1129,6 +1312,8 @@ static ssize_t uvcg_frame_dw_frame_interval_store(struct config_item *item,
 	kfree(ch->dw_frame_interval);
 	ch->dw_frame_interval = frm_intrv;
 	ch->frame.b_frame_interval_type = n;
+	sort(ch->dw_frame_interval, n, sizeof(*ch->dw_frame_interval),
+	     uvcg_config_compare_u32, NULL);
 	ret = len;
 
 end:
@@ -1140,6 +1325,7 @@ end:
 UVC_ATTR(uvcg_frame_, dw_frame_interval, dwFrameInterval);
 
 static struct configfs_attribute *uvcg_frame_attrs[] = {
+	&uvcg_frame_attr_b_frame_index,
 	&uvcg_frame_attr_bm_capabilities,
 	&uvcg_frame_attr_w_width,
 	&uvcg_frame_attr_w_height,
@@ -1152,6 +1338,7 @@ static struct configfs_attribute *uvcg_frame_attrs[] = {
 };
 
 static const struct config_item_type uvcg_frame_type = {
+	.ct_item_ops	= &uvcg_config_item_ops,
 	.ct_attrs	= uvcg_frame_attrs,
 	.ct_owner	= THIS_MODULE,
 };
@@ -1170,12 +1357,12 @@ static struct config_item *uvcg_frame_make(struct config_group *group,
 
 	h->frame.b_descriptor_type		= USB_DT_CS_INTERFACE;
 	h->frame.b_frame_index			= 1;
-	h->frame.w_width			= cpu_to_le16(640);
-	h->frame.w_height			= cpu_to_le16(360);
-	h->frame.dw_min_bit_rate		= cpu_to_le32(18432000);
-	h->frame.dw_max_bit_rate		= cpu_to_le32(55296000);
-	h->frame.dw_max_video_frame_buffer_size	= cpu_to_le32(460800);
-	h->frame.dw_default_frame_interval	= cpu_to_le32(666666);
+	h->frame.w_width			= 640;
+	h->frame.w_height			= 360;
+	h->frame.dw_min_bit_rate		= 18432000;
+	h->frame.dw_max_bit_rate		= 55296000;
+	h->frame.dw_max_video_frame_buffer_size	= 460800;
+	h->frame.dw_default_frame_interval	= 666666;
 
 	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;
 	opts = to_f_uvc_opts(opts_item);
@@ -1203,7 +1390,6 @@ static struct config_item *uvcg_frame_make(struct config_group *group,
 
 static void uvcg_frame_drop(struct config_group *group, struct config_item *item)
 {
-	struct uvcg_frame *h = to_uvcg_frame(item);
 	struct uvcg_format *fmt;
 	struct f_uvc_opts *opts;
 	struct config_item *opts_item;
@@ -1214,11 +1400,31 @@ static void uvcg_frame_drop(struct config_group *group, struct config_item *item
 	mutex_lock(&opts->lock);
 	fmt = to_uvcg_format(&group->cg_item);
 	--fmt->num_frames;
-	kfree(h);
 	mutex_unlock(&opts->lock);
+
+	config_item_put(item);
+}
+
+static void uvcg_format_set_indices(struct config_group *fmt)
+{
+	struct config_item *ci;
+	unsigned int i = 1;
+
+	list_for_each_entry(ci, &fmt->cg_children, ci_entry) {
+		struct uvcg_frame *frm;
+
+		if (ci->ci_type != &uvcg_frame_type)
+			continue;
+
+		frm = to_uvcg_frame(ci);
+		frm->frame.b_frame_index = i++;
+	}
 }
 
-/* streaming/uncompressed/<NAME> */
+/* -----------------------------------------------------------------------------
+ * streaming/uncompressed/<NAME>
+ */
+
 struct uvcg_uncompressed {
 	struct uvcg_format		fmt;
 	struct uvc_format_uncompressed	desc;
@@ -1290,7 +1496,7 @@ end:
 
 UVC_ATTR(uvcg_uncompressed_, guid_format, guidFormat);
 
-#define UVCG_UNCOMPRESSED_ATTR_RO(cname, aname, conv)			\
+#define UVCG_UNCOMPRESSED_ATTR_RO(cname, aname, bits)			\
 static ssize_t uvcg_uncompressed_##cname##_show(			\
 	struct config_item *item, char *page)				\
 {									\
@@ -1306,7 +1512,7 @@ static ssize_t uvcg_uncompressed_##cname##_show(			\
 	opts = to_f_uvc_opts(opts_item);				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(u->desc.aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(u->desc.aname));\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -1315,7 +1521,7 @@ static ssize_t uvcg_uncompressed_##cname##_show(			\
 									\
 UVC_ATTR_RO(uvcg_uncompressed_, cname, aname);
 
-#define UVCG_UNCOMPRESSED_ATTR(cname, aname, conv)			\
+#define UVCG_UNCOMPRESSED_ATTR(cname, aname, bits)			\
 static ssize_t uvcg_uncompressed_##cname##_show(			\
 	struct config_item *item, char *page)				\
 {									\
@@ -1331,7 +1537,7 @@ static ssize_t uvcg_uncompressed_##cname##_show(			\
 	opts = to_f_uvc_opts(opts_item);				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(u->desc.aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(u->desc.aname));\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -1378,16 +1584,12 @@ end:									\
 									\
 UVC_ATTR(uvcg_uncompressed_, cname, aname);
 
-#define identity_conv(x) (x)
-
-UVCG_UNCOMPRESSED_ATTR(b_bits_per_pixel, bBitsPerPixel, identity_conv);
-UVCG_UNCOMPRESSED_ATTR(b_default_frame_index, bDefaultFrameIndex,
-		       identity_conv);
-UVCG_UNCOMPRESSED_ATTR_RO(b_aspect_ratio_x, bAspectRatioX, identity_conv);
-UVCG_UNCOMPRESSED_ATTR_RO(b_aspect_ratio_y, bAspectRatioY, identity_conv);
-UVCG_UNCOMPRESSED_ATTR_RO(bm_interface_flags, bmInterfaceFlags, identity_conv);
-
-#undef identity_conv
+UVCG_UNCOMPRESSED_ATTR_RO(b_format_index, bFormatIndex, 8);
+UVCG_UNCOMPRESSED_ATTR(b_bits_per_pixel, bBitsPerPixel, 8);
+UVCG_UNCOMPRESSED_ATTR(b_default_frame_index, bDefaultFrameIndex, 8);
+UVCG_UNCOMPRESSED_ATTR_RO(b_aspect_ratio_x, bAspectRatioX, 8);
+UVCG_UNCOMPRESSED_ATTR_RO(b_aspect_ratio_y, bAspectRatioY, 8);
+UVCG_UNCOMPRESSED_ATTR_RO(bm_interface_flags, bmInterfaceFlags, 8);
 
 #undef UVCG_UNCOMPRESSED_ATTR
 #undef UVCG_UNCOMPRESSED_ATTR_RO
@@ -1410,6 +1612,7 @@ uvcg_uncompressed_bma_controls_store(struct config_item *item,
 UVC_ATTR(uvcg_uncompressed_, bma_controls, bmaControls);
 
 static struct configfs_attribute *uvcg_uncompressed_attrs[] = {
+	&uvcg_uncompressed_attr_b_format_index,
 	&uvcg_uncompressed_attr_guid_format,
 	&uvcg_uncompressed_attr_b_bits_per_pixel,
 	&uvcg_uncompressed_attr_b_default_frame_index,
@@ -1421,6 +1624,7 @@ static struct configfs_attribute *uvcg_uncompressed_attrs[] = {
 };
 
 static const struct config_item_type uvcg_uncompressed_type = {
+	.ct_item_ops	= &uvcg_config_item_ops,
 	.ct_group_ops	= &uvcg_uncompressed_group_ops,
 	.ct_attrs	= uvcg_uncompressed_attrs,
 	.ct_owner	= THIS_MODULE,
@@ -1457,25 +1661,23 @@ static struct config_group *uvcg_uncompressed_make(struct config_group *group,
 	return &h->fmt.group;
 }
 
-static void uvcg_uncompressed_drop(struct config_group *group,
-			    struct config_item *item)
-{
-	struct uvcg_uncompressed *h = to_uvcg_uncompressed(item);
-
-	kfree(h);
-}
-
 static struct configfs_group_operations uvcg_uncompressed_grp_ops = {
 	.make_group		= uvcg_uncompressed_make,
-	.drop_item		= uvcg_uncompressed_drop,
 };
 
-static const struct config_item_type uvcg_uncompressed_grp_type = {
-	.ct_group_ops	= &uvcg_uncompressed_grp_ops,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_uncompressed_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_group_ops	= &uvcg_uncompressed_grp_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "uncompressed",
 };
 
-/* streaming/mjpeg/<NAME> */
+/* -----------------------------------------------------------------------------
+ * streaming/mjpeg/<NAME>
+ */
+
 struct uvcg_mjpeg {
 	struct uvcg_format		fmt;
 	struct uvc_format_mjpeg		desc;
@@ -1493,7 +1695,7 @@ static struct configfs_group_operations uvcg_mjpeg_group_ops = {
 	.drop_item		= uvcg_frame_drop,
 };
 
-#define UVCG_MJPEG_ATTR_RO(cname, aname, conv)				\
+#define UVCG_MJPEG_ATTR_RO(cname, aname, bits)				\
 static ssize_t uvcg_mjpeg_##cname##_show(struct config_item *item, char *page)\
 {									\
 	struct uvcg_mjpeg *u = to_uvcg_mjpeg(item);			\
@@ -1508,7 +1710,7 @@ static ssize_t uvcg_mjpeg_##cname##_show(struct config_item *item, char *page)\
 	opts = to_f_uvc_opts(opts_item);				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(u->desc.aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(u->desc.aname));\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -1517,7 +1719,7 @@ static ssize_t uvcg_mjpeg_##cname##_show(struct config_item *item, char *page)\
 									\
 UVC_ATTR_RO(uvcg_mjpeg_, cname, aname)
 
-#define UVCG_MJPEG_ATTR(cname, aname, conv)				\
+#define UVCG_MJPEG_ATTR(cname, aname, bits)				\
 static ssize_t uvcg_mjpeg_##cname##_show(struct config_item *item, char *page)\
 {									\
 	struct uvcg_mjpeg *u = to_uvcg_mjpeg(item);			\
@@ -1532,7 +1734,7 @@ static ssize_t uvcg_mjpeg_##cname##_show(struct config_item *item, char *page)\
 	opts = to_f_uvc_opts(opts_item);				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(u->desc.aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(u->desc.aname));\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -1579,16 +1781,12 @@ end:									\
 									\
 UVC_ATTR(uvcg_mjpeg_, cname, aname)
 
-#define identity_conv(x) (x)
-
-UVCG_MJPEG_ATTR(b_default_frame_index, bDefaultFrameIndex,
-		       identity_conv);
-UVCG_MJPEG_ATTR_RO(bm_flags, bmFlags, identity_conv);
-UVCG_MJPEG_ATTR_RO(b_aspect_ratio_x, bAspectRatioX, identity_conv);
-UVCG_MJPEG_ATTR_RO(b_aspect_ratio_y, bAspectRatioY, identity_conv);
-UVCG_MJPEG_ATTR_RO(bm_interface_flags, bmInterfaceFlags, identity_conv);
-
-#undef identity_conv
+UVCG_MJPEG_ATTR_RO(b_format_index, bFormatIndex, 8);
+UVCG_MJPEG_ATTR(b_default_frame_index, bDefaultFrameIndex, 8);
+UVCG_MJPEG_ATTR_RO(bm_flags, bmFlags, 8);
+UVCG_MJPEG_ATTR_RO(b_aspect_ratio_x, bAspectRatioX, 8);
+UVCG_MJPEG_ATTR_RO(b_aspect_ratio_y, bAspectRatioY, 8);
+UVCG_MJPEG_ATTR_RO(bm_interface_flags, bmInterfaceFlags, 8);
 
 #undef UVCG_MJPEG_ATTR
 #undef UVCG_MJPEG_ATTR_RO
@@ -1611,6 +1809,7 @@ uvcg_mjpeg_bma_controls_store(struct config_item *item,
 UVC_ATTR(uvcg_mjpeg_, bma_controls, bmaControls);
 
 static struct configfs_attribute *uvcg_mjpeg_attrs[] = {
+	&uvcg_mjpeg_attr_b_format_index,
 	&uvcg_mjpeg_attr_b_default_frame_index,
 	&uvcg_mjpeg_attr_bm_flags,
 	&uvcg_mjpeg_attr_b_aspect_ratio_x,
@@ -1621,6 +1820,7 @@ static struct configfs_attribute *uvcg_mjpeg_attrs[] = {
 };
 
 static const struct config_item_type uvcg_mjpeg_type = {
+	.ct_item_ops	= &uvcg_config_item_ops,
 	.ct_group_ops	= &uvcg_mjpeg_group_ops,
 	.ct_attrs	= uvcg_mjpeg_attrs,
 	.ct_owner	= THIS_MODULE,
@@ -1651,56 +1851,42 @@ static struct config_group *uvcg_mjpeg_make(struct config_group *group,
 	return &h->fmt.group;
 }
 
-static void uvcg_mjpeg_drop(struct config_group *group,
-			    struct config_item *item)
-{
-	struct uvcg_mjpeg *h = to_uvcg_mjpeg(item);
-
-	kfree(h);
-}
-
 static struct configfs_group_operations uvcg_mjpeg_grp_ops = {
 	.make_group		= uvcg_mjpeg_make,
-	.drop_item		= uvcg_mjpeg_drop,
 };
 
-static const struct config_item_type uvcg_mjpeg_grp_type = {
-	.ct_group_ops	= &uvcg_mjpeg_grp_ops,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_mjpeg_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_group_ops	= &uvcg_mjpeg_grp_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "mjpeg",
 };
 
-/* streaming/color_matching/default */
-static struct uvcg_default_color_matching {
-	struct config_group	group;
-} uvcg_default_color_matching;
-
-static inline struct uvcg_default_color_matching
-*to_uvcg_default_color_matching(struct config_item *item)
-{
-	return container_of(to_config_group(item),
-			    struct uvcg_default_color_matching, group);
-}
+/* -----------------------------------------------------------------------------
+ * streaming/color_matching/default
+ */
 
-#define UVCG_DEFAULT_COLOR_MATCHING_ATTR(cname, aname, conv)		\
+#define UVCG_DEFAULT_COLOR_MATCHING_ATTR(cname, aname, bits)		\
 static ssize_t uvcg_default_color_matching_##cname##_show(		\
-	struct config_item *item, char *page)		\
+	struct config_item *item, char *page)				\
 {									\
-	struct uvcg_default_color_matching *dc =			\
-		to_uvcg_default_color_matching(item);			\
+	struct config_group *group = to_config_group(item);		\
 	struct f_uvc_opts *opts;					\
 	struct config_item *opts_item;					\
-	struct mutex *su_mutex = &dc->group.cg_subsys->su_mutex;	\
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;		\
 	struct uvc_color_matching_descriptor *cd;			\
 	int result;							\
 									\
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
 									\
-	opts_item = dc->group.cg_item.ci_parent->ci_parent->ci_parent;	\
+	opts_item = group->cg_item.ci_parent->ci_parent->ci_parent;	\
 	opts = to_f_uvc_opts(opts_item);				\
 	cd = &opts->uvc_color_matching;					\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(cd->aname));		\
+	result = sprintf(page, "%u\n", le##bits##_to_cpu(cd->aname));	\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -1709,16 +1895,10 @@ static ssize_t uvcg_default_color_matching_##cname##_show(		\
 									\
 UVC_ATTR_RO(uvcg_default_color_matching_, cname, aname)
 
-#define identity_conv(x) (x)
-
-UVCG_DEFAULT_COLOR_MATCHING_ATTR(b_color_primaries, bColorPrimaries,
-				 identity_conv);
+UVCG_DEFAULT_COLOR_MATCHING_ATTR(b_color_primaries, bColorPrimaries, 8);
 UVCG_DEFAULT_COLOR_MATCHING_ATTR(b_transfer_characteristics,
-				 bTransferCharacteristics, identity_conv);
-UVCG_DEFAULT_COLOR_MATCHING_ATTR(b_matrix_coefficients, bMatrixCoefficients,
-				 identity_conv);
-
-#undef identity_conv
+				 bTransferCharacteristics, 8);
+UVCG_DEFAULT_COLOR_MATCHING_ATTR(b_matrix_coefficients, bMatrixCoefficients, 8);
 
 #undef UVCG_DEFAULT_COLOR_MATCHING_ATTR
 
@@ -1729,41 +1909,54 @@ static struct configfs_attribute *uvcg_default_color_matching_attrs[] = {
 	NULL,
 };
 
-static const struct config_item_type uvcg_default_color_matching_type = {
-	.ct_attrs	= uvcg_default_color_matching_attrs,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_default_color_matching_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_attrs	= uvcg_default_color_matching_attrs,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "default",
 };
 
-/* struct uvcg_color_matching {}; */
-
-/* streaming/color_matching */
-static struct uvcg_color_matching_grp {
-	struct config_group	group;
-} uvcg_color_matching_grp;
+/* -----------------------------------------------------------------------------
+ * streaming/color_matching
+ */
 
-static const struct config_item_type uvcg_color_matching_grp_type = {
-	.ct_owner = THIS_MODULE,
+static const struct uvcg_config_group_type uvcg_color_matching_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "color_matching",
+	.children = (const struct uvcg_config_group_type*[]) {
+		&uvcg_default_color_matching_type,
+		NULL,
+	},
 };
 
-/* streaming/class/{fs|hs|ss} */
-static struct uvcg_streaming_class {
-	struct config_group	group;
-} uvcg_streaming_class_fs, uvcg_streaming_class_hs, uvcg_streaming_class_ss;
+/* -----------------------------------------------------------------------------
+ * streaming/class/{fs|hs|ss}
+ */
 
+struct uvcg_streaming_class_group {
+	struct config_group group;
+	const char *name;
+};
 
 static inline struct uvc_descriptor_header
 ***__uvcg_get_stream_class_arr(struct config_item *i, struct f_uvc_opts *o)
 {
-	struct uvcg_streaming_class *cl = container_of(to_config_group(i),
-		struct uvcg_streaming_class, group);
+	struct uvcg_streaming_class_group *group =
+		container_of(i, struct uvcg_streaming_class_group,
+			     group.cg_item);
 
-	if (cl == &uvcg_streaming_class_fs)
+	if (!strcmp(group->name, "fs"))
 		return &o->uvc_fs_streaming_cls;
 
-	if (cl == &uvcg_streaming_class_hs)
+	if (!strcmp(group->name, "hs"))
 		return &o->uvc_hs_streaming_cls;
 
-	if (cl == &uvcg_streaming_class_ss)
+	if (!strcmp(group->name, "ss"))
 		return &o->uvc_ss_streaming_cls;
 
 	return NULL;
@@ -1922,24 +2115,22 @@ static int __uvcg_fill_strm(void *priv1, void *priv2, void *priv3, int n,
 		struct uvcg_format *fmt = priv1;
 
 		if (fmt->type == UVCG_UNCOMPRESSED) {
-			struct uvc_format_uncompressed *unc = *dest;
 			struct uvcg_uncompressed *u =
 				container_of(fmt, struct uvcg_uncompressed,
 					     fmt);
 
+			u->desc.bFormatIndex = n + 1;
+			u->desc.bNumFrameDescriptors = fmt->num_frames;
 			memcpy(*dest, &u->desc, sizeof(u->desc));
 			*dest += sizeof(u->desc);
-			unc->bNumFrameDescriptors = fmt->num_frames;
-			unc->bFormatIndex = n + 1;
 		} else if (fmt->type == UVCG_MJPEG) {
-			struct uvc_format_mjpeg *mjp = *dest;
 			struct uvcg_mjpeg *m =
 				container_of(fmt, struct uvcg_mjpeg, fmt);
 
+			m->desc.bFormatIndex = n + 1;
+			m->desc.bNumFrameDescriptors = fmt->num_frames;
 			memcpy(*dest, &m->desc, sizeof(m->desc));
 			*dest += sizeof(m->desc);
-			mjp->bNumFrameDescriptors = fmt->num_frames;
-			mjp->bFormatIndex = n + 1;
 		} else {
 			return -EINVAL;
 		}
@@ -2038,6 +2229,7 @@ static int uvcg_streaming_class_allow_link(struct config_item *src,
 unlock:
 	mutex_unlock(&opts->lock);
 out:
+	config_item_put(header);
 	mutex_unlock(su_mutex);
 	return ret;
 }
@@ -2078,10 +2270,12 @@ static void uvcg_streaming_class_drop_link(struct config_item *src,
 unlock:
 	mutex_unlock(&opts->lock);
 out:
+	config_item_put(header);
 	mutex_unlock(su_mutex);
 }
 
 static struct configfs_item_operations uvcg_streaming_class_item_ops = {
+	.release	= uvcg_config_item_release,
 	.allow_link	= uvcg_streaming_class_allow_link,
 	.drop_link	= uvcg_streaming_class_drop_link,
 };
@@ -2091,36 +2285,109 @@ static const struct config_item_type uvcg_streaming_class_type = {
 	.ct_owner	= THIS_MODULE,
 };
 
-/* streaming/class */
-static struct uvcg_streaming_class_grp {
-	struct config_group	group;
-} uvcg_streaming_class_grp;
+/* -----------------------------------------------------------------------------
+ * streaming/class
+ */
+
+static int uvcg_streaming_class_create_children(struct config_group *parent)
+{
+	static const char * const names[] = { "fs", "hs", "ss" };
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(names); ++i) {
+		struct uvcg_streaming_class_group *group;
+
+		group = kzalloc(sizeof(*group), GFP_KERNEL);
+		if (!group)
+			return -ENOMEM;
 
-static const struct config_item_type uvcg_streaming_class_grp_type = {
-	.ct_owner = THIS_MODULE,
+		group->name = names[i];
+
+		config_group_init_type_name(&group->group, group->name,
+					    &uvcg_streaming_class_type);
+		configfs_add_default_group(&group->group, parent);
+	}
+
+	return 0;
+}
+
+static const struct uvcg_config_group_type uvcg_streaming_class_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "class",
+	.create_children = uvcg_streaming_class_create_children,
 };
 
-/* streaming */
-static struct uvcg_streaming_grp {
-	struct config_group	group;
-} uvcg_streaming_grp;
+/* -----------------------------------------------------------------------------
+ * streaming
+ */
 
-static const struct config_item_type uvcg_streaming_grp_type = {
-	.ct_owner = THIS_MODULE,
+static ssize_t uvcg_default_streaming_b_interface_number_show(
+	struct config_item *item, char *page)
+{
+	struct config_group *group = to_config_group(item);
+	struct mutex *su_mutex = &group->cg_subsys->su_mutex;
+	struct config_item *opts_item;
+	struct f_uvc_opts *opts;
+	int result = 0;
+
+	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
+
+	opts_item = item->ci_parent;
+	opts = to_f_uvc_opts(opts_item);
+
+	mutex_lock(&opts->lock);
+	result += sprintf(page, "%u\n", opts->streaming_interface);
+	mutex_unlock(&opts->lock);
+
+	mutex_unlock(su_mutex);
+
+	return result;
+}
+
+UVC_ATTR_RO(uvcg_default_streaming_, b_interface_number, bInterfaceNumber);
+
+static struct configfs_attribute *uvcg_default_streaming_attrs[] = {
+	&uvcg_default_streaming_attr_b_interface_number,
+	NULL,
+};
+
+static const struct uvcg_config_group_type uvcg_streaming_grp_type = {
+	.type = {
+		.ct_item_ops	= &uvcg_config_item_ops,
+		.ct_attrs	= uvcg_default_streaming_attrs,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "streaming",
+	.children = (const struct uvcg_config_group_type*[]) {
+		&uvcg_streaming_header_grp_type,
+		&uvcg_uncompressed_grp_type,
+		&uvcg_mjpeg_grp_type,
+		&uvcg_color_matching_grp_type,
+		&uvcg_streaming_class_grp_type,
+		NULL,
+	},
 };
 
-static void uvc_attr_release(struct config_item *item)
+/* -----------------------------------------------------------------------------
+ * UVC function
+ */
+
+static void uvc_func_item_release(struct config_item *item)
 {
 	struct f_uvc_opts *opts = to_f_uvc_opts(item);
 
+	uvcg_config_remove_children(to_config_group(item));
 	usb_put_function_instance(&opts->func_inst);
 }
 
-static struct configfs_item_operations uvc_item_ops = {
-	.release		= uvc_attr_release,
+static struct configfs_item_operations uvc_func_item_ops = {
+	.release	= uvc_func_item_release,
 };
 
-#define UVCG_OPTS_ATTR(cname, aname, conv, str2u, uxx, vnoc, limit)	\
+#define UVCG_OPTS_ATTR(cname, aname, limit)				\
 static ssize_t f_uvc_opts_##cname##_show(				\
 	struct config_item *item, char *page)				\
 {									\
@@ -2128,7 +2395,7 @@ static ssize_t f_uvc_opts_##cname##_show(				\
 	int result;							\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(opts->cname));		\
+	result = sprintf(page, "%u\n", opts->cname);			\
 	mutex_unlock(&opts->lock);					\
 									\
 	return result;							\
@@ -2139,8 +2406,8 @@ f_uvc_opts_##cname##_store(struct config_item *item,			\
 			   const char *page, size_t len)		\
 {									\
 	struct f_uvc_opts *opts = to_f_uvc_opts(item);			\
+	unsigned int num;						\
 	int ret;							\
-	uxx num;							\
 									\
 	mutex_lock(&opts->lock);					\
 	if (opts->refcnt) {						\
@@ -2148,7 +2415,7 @@ f_uvc_opts_##cname##_store(struct config_item *item,			\
 		goto end;						\
 	}								\
 									\
-	ret = str2u(page, 0, &num);					\
+	ret = kstrtouint(page, 0, &num);				\
 	if (ret)							\
 		goto end;						\
 									\
@@ -2156,7 +2423,7 @@ f_uvc_opts_##cname##_store(struct config_item *item,			\
 		ret = -EINVAL;						\
 		goto end;						\
 	}								\
-	opts->cname = vnoc(num);					\
+	opts->cname = num;						\
 	ret = len;							\
 end:									\
 	mutex_unlock(&opts->lock);					\
@@ -2165,16 +2432,9 @@ end:									\
 									\
 UVC_ATTR(f_uvc_opts_, cname, cname)
 
-#define identity_conv(x) (x)
-
-UVCG_OPTS_ATTR(streaming_interval, streaming_interval, identity_conv,
-	       kstrtou8, u8, identity_conv, 16);
-UVCG_OPTS_ATTR(streaming_maxpacket, streaming_maxpacket, le16_to_cpu,
-	       kstrtou16, u16, le16_to_cpu, 3072);
-UVCG_OPTS_ATTR(streaming_maxburst, streaming_maxburst, identity_conv,
-	       kstrtou8, u8, identity_conv, 15);
-
-#undef identity_conv
+UVCG_OPTS_ATTR(streaming_interval, streaming_interval, 16);
+UVCG_OPTS_ATTR(streaming_maxpacket, streaming_maxpacket, 3072);
+UVCG_OPTS_ATTR(streaming_maxburst, streaming_maxburst, 15);
 
 #undef UVCG_OPTS_ATTR
 
@@ -2185,123 +2445,31 @@ static struct configfs_attribute *uvc_attrs[] = {
 	NULL,
 };
 
-static const struct config_item_type uvc_func_type = {
-	.ct_item_ops	= &uvc_item_ops,
-	.ct_attrs	= uvc_attrs,
-	.ct_owner	= THIS_MODULE,
+static const struct uvcg_config_group_type uvc_func_type = {
+	.type = {
+		.ct_item_ops	= &uvc_func_item_ops,
+		.ct_attrs	= uvc_attrs,
+		.ct_owner	= THIS_MODULE,
+	},
+	.name = "",
+	.children = (const struct uvcg_config_group_type*[]) {
+		&uvcg_control_grp_type,
+		&uvcg_streaming_grp_type,
+		NULL,
+	},
 };
 
 int uvcg_attach_configfs(struct f_uvc_opts *opts)
 {
-	config_group_init_type_name(&uvcg_control_header_grp.group,
-				    "header",
-				    &uvcg_control_header_grp_type);
-
-	config_group_init_type_name(&uvcg_default_processing.group,
-			"default", &uvcg_default_processing_type);
-	config_group_init_type_name(&uvcg_processing_grp.group,
-			"processing", &uvcg_processing_grp_type);
-	configfs_add_default_group(&uvcg_default_processing.group,
-			&uvcg_processing_grp.group);
-
-	config_group_init_type_name(&uvcg_default_camera.group,
-			"default", &uvcg_default_camera_type);
-	config_group_init_type_name(&uvcg_camera_grp.group,
-			"camera", &uvcg_camera_grp_type);
-	configfs_add_default_group(&uvcg_default_camera.group,
-			&uvcg_camera_grp.group);
-
-	config_group_init_type_name(&uvcg_default_output.group,
-			"default", &uvcg_default_output_type);
-	config_group_init_type_name(&uvcg_output_grp.group,
-			"output", &uvcg_output_grp_type);
-	configfs_add_default_group(&uvcg_default_output.group,
-			&uvcg_output_grp.group);
-
-	config_group_init_type_name(&uvcg_terminal_grp.group,
-			"terminal", &uvcg_terminal_grp_type);
-	configfs_add_default_group(&uvcg_camera_grp.group,
-			&uvcg_terminal_grp.group);
-	configfs_add_default_group(&uvcg_output_grp.group,
-			&uvcg_terminal_grp.group);
-
-	config_group_init_type_name(&uvcg_control_class_fs.group,
-			"fs", &uvcg_control_class_type);
-	config_group_init_type_name(&uvcg_control_class_ss.group,
-			"ss", &uvcg_control_class_type);
-	config_group_init_type_name(&uvcg_control_class_grp.group,
-			"class",
-			&uvcg_control_class_grp_type);
-	configfs_add_default_group(&uvcg_control_class_fs.group,
-			&uvcg_control_class_grp.group);
-	configfs_add_default_group(&uvcg_control_class_ss.group,
-			&uvcg_control_class_grp.group);
-
-	config_group_init_type_name(&uvcg_control_grp.group,
-			"control",
-			&uvcg_control_grp_type);
-	configfs_add_default_group(&uvcg_control_header_grp.group,
-			&uvcg_control_grp.group);
-	configfs_add_default_group(&uvcg_processing_grp.group,
-			&uvcg_control_grp.group);
-	configfs_add_default_group(&uvcg_terminal_grp.group,
-			&uvcg_control_grp.group);
-	configfs_add_default_group(&uvcg_control_class_grp.group,
-			&uvcg_control_grp.group);
-
-	config_group_init_type_name(&uvcg_streaming_header_grp.group,
-				    "header",
-				    &uvcg_streaming_header_grp_type);
-	config_group_init_type_name(&uvcg_uncompressed_grp.group,
-				    "uncompressed",
-				    &uvcg_uncompressed_grp_type);
-	config_group_init_type_name(&uvcg_mjpeg_grp.group,
-				    "mjpeg",
-				    &uvcg_mjpeg_grp_type);
-	config_group_init_type_name(&uvcg_default_color_matching.group,
-				    "default",
-				    &uvcg_default_color_matching_type);
-	config_group_init_type_name(&uvcg_color_matching_grp.group,
-			"color_matching",
-			&uvcg_color_matching_grp_type);
-	configfs_add_default_group(&uvcg_default_color_matching.group,
-			&uvcg_color_matching_grp.group);
-
-	config_group_init_type_name(&uvcg_streaming_class_fs.group,
-			"fs", &uvcg_streaming_class_type);
-	config_group_init_type_name(&uvcg_streaming_class_hs.group,
-			"hs", &uvcg_streaming_class_type);
-	config_group_init_type_name(&uvcg_streaming_class_ss.group,
-			"ss", &uvcg_streaming_class_type);
-	config_group_init_type_name(&uvcg_streaming_class_grp.group,
-			"class", &uvcg_streaming_class_grp_type);
-	configfs_add_default_group(&uvcg_streaming_class_fs.group,
-			&uvcg_streaming_class_grp.group);
-	configfs_add_default_group(&uvcg_streaming_class_hs.group,
-			&uvcg_streaming_class_grp.group);
-	configfs_add_default_group(&uvcg_streaming_class_ss.group,
-			&uvcg_streaming_class_grp.group);
-
-	config_group_init_type_name(&uvcg_streaming_grp.group,
-			"streaming", &uvcg_streaming_grp_type);
-	configfs_add_default_group(&uvcg_streaming_header_grp.group,
-			&uvcg_streaming_grp.group);
-	configfs_add_default_group(&uvcg_uncompressed_grp.group,
-			&uvcg_streaming_grp.group);
-	configfs_add_default_group(&uvcg_mjpeg_grp.group,
-			&uvcg_streaming_grp.group);
-	configfs_add_default_group(&uvcg_color_matching_grp.group,
-			&uvcg_streaming_grp.group);
-	configfs_add_default_group(&uvcg_streaming_class_grp.group,
-			&uvcg_streaming_grp.group);
-
-	config_group_init_type_name(&opts->func_inst.group,
-			"",
-			&uvc_func_type);
-	configfs_add_default_group(&uvcg_control_grp.group,
-			&opts->func_inst.group);
-	configfs_add_default_group(&uvcg_streaming_grp.group,
-			&opts->func_inst.group);
+	int ret;
 
-	return 0;
+	config_group_init_type_name(&opts->func_inst.group, uvc_func_type.name,
+				    &uvc_func_type.type);
+
+	ret = uvcg_config_create_children(&opts->func_inst.group,
+					  &uvc_func_type);
+	if (ret < 0)
+		config_group_put(&opts->func_inst.group);
+
+	return ret;
 }
diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c
index 7f1ca3b57823..a1183eccee22 100644
--- a/drivers/usb/gadget/function/uvc_v4l2.c
+++ b/drivers/usb/gadget/function/uvc_v4l2.c
@@ -115,8 +115,8 @@ uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt)
 	}
 
 	if (i == ARRAY_SIZE(uvc_formats)) {
-		printk(KERN_INFO "Unsupported format 0x%08x.\n",
-			fmt->fmt.pix.pixelformat);
+		uvcg_info(&uvc->func, "Unsupported format 0x%08x.\n",
+			  fmt->fmt.pix.pixelformat);
 		return -EINVAL;
 	}
 
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index d3567b90343a..5c042f380708 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -125,6 +125,23 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
  * Request handling
  */
 
+static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
+{
+	int ret;
+
+	ret = usb_ep_queue(video->ep, req, GFP_ATOMIC);
+	if (ret < 0) {
+		uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n",
+			 ret);
+
+		/* Isochronous endpoints can't be halted. */
+		if (usb_endpoint_xfer_bulk(video->ep->desc))
+			usb_ep_set_halt(video->ep);
+	}
+
+	return ret;
+}
+
 /*
  * I somehow feel that synchronisation won't be easy to achieve here. We have
  * three events that control USB requests submission:
@@ -169,13 +186,14 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
 		break;
 
 	case -ESHUTDOWN:	/* disconnect from host. */
-		printk(KERN_DEBUG "VS request cancelled.\n");
+		uvcg_dbg(&video->uvc->func, "VS request cancelled.\n");
 		uvcg_queue_cancel(queue, 1);
 		goto requeue;
 
 	default:
-		printk(KERN_INFO "VS request completed with status %d.\n",
-			req->status);
+		uvcg_info(&video->uvc->func,
+			  "VS request completed with status %d.\n",
+			  req->status);
 		uvcg_queue_cancel(queue, 0);
 		goto requeue;
 	}
@@ -189,14 +207,13 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
 
 	video->encode(req, video, buf);
 
-	if ((ret = usb_ep_queue(ep, req, GFP_ATOMIC)) < 0) {
-		printk(KERN_INFO "Failed to queue request (%d).\n", ret);
-		usb_ep_set_halt(ep);
-		spin_unlock_irqrestore(&video->queue.irqlock, flags);
+	ret = uvcg_video_ep_queue(video, req);
+	spin_unlock_irqrestore(&video->queue.irqlock, flags);
+
+	if (ret < 0) {
 		uvcg_queue_cancel(queue, 0);
 		goto requeue;
 	}
-	spin_unlock_irqrestore(&video->queue.irqlock, flags);
 
 	return;
 
@@ -316,15 +333,13 @@ int uvcg_video_pump(struct uvc_video *video)
 		video->encode(req, video, buf);
 
 		/* Queue the USB request */
-		ret = usb_ep_queue(video->ep, req, GFP_ATOMIC);
+		ret = uvcg_video_ep_queue(video, req);
+		spin_unlock_irqrestore(&queue->irqlock, flags);
+
 		if (ret < 0) {
-			printk(KERN_INFO "Failed to queue request (%d)\n", ret);
-			usb_ep_set_halt(video->ep);
-			spin_unlock_irqrestore(&queue->irqlock, flags);
 			uvcg_queue_cancel(queue, 0);
 			break;
 		}
-		spin_unlock_irqrestore(&queue->irqlock, flags);
 	}
 
 	spin_lock_irqsave(&video->req_lock, flags);
@@ -342,8 +357,8 @@ int uvcg_video_enable(struct uvc_video *video, int enable)
 	int ret;
 
 	if (video->ep == NULL) {
-		printk(KERN_INFO "Video enable failed, device is "
-			"uninitialized.\n");
+		uvcg_info(&video->uvc->func,
+			  "Video enable failed, device is uninitialized.\n");
 		return -ENODEV;
 	}
 
@@ -375,11 +390,12 @@ int uvcg_video_enable(struct uvc_video *video, int enable)
 /*
  * Initialize the UVC video stream.
  */
-int uvcg_video_init(struct uvc_video *video)
+int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
 {
 	INIT_LIST_HEAD(&video->req_free);
 	spin_lock_init(&video->req_lock);
 
+	video->uvc = uvc;
 	video->fcc = V4L2_PIX_FMT_YUYV;
 	video->bpp = 16;
 	video->width = 320;
diff --git a/drivers/usb/gadget/function/uvc_video.h b/drivers/usb/gadget/function/uvc_video.h
index 7d77122b0ff9..278dc52c7604 100644
--- a/drivers/usb/gadget/function/uvc_video.h
+++ b/drivers/usb/gadget/function/uvc_video.h
@@ -18,6 +18,6 @@ int uvcg_video_pump(struct uvc_video *video);
 
 int uvcg_video_enable(struct uvc_video *video, int enable);
 
-int uvcg_video_init(struct uvc_video *video);
+int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc);
 
 #endif /* __UVC_VIDEO_H__ */