media: uvcvideo: Use standard names for menus

Instead of duplicating the menu info, use the one from the core.
Also, do not use extra memory for 1:1 mappings.
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

drivers/media/usb/uvc/uvc_ctrl.c

@@ -364,19 +364,45 @@ static const u32 uvc_control_classes[] = {
 	V4L2_CID_USER_CLASS,
 };
 
-static const struct uvc_menu_info power_line_frequency_controls[] = {
-	{ 0, "Disabled" },
-	{ 1, "50 Hz" },
-	{ 2, "60 Hz" },
-	{ 3, "Auto" },
-};
+static const int exposure_auto_mapping[] = { 2, 1, 4, 8 };
 
-static const struct uvc_menu_info exposure_auto_controls[] = {
-	{ 2, "Auto Mode" },
-	{ 1, "Manual Mode" },
-	{ 4, "Shutter Priority Mode" },
-	{ 8, "Aperture Priority Mode" },
-};
+/*
+ * This function translates the V4L2 menu index @idx, as exposed to userspace as
+ * the V4L2 control value, to the corresponding UVC control value used by the
+ * device. The custom menu_mapping in the control @mapping is used when
+ * available, otherwise the function assumes that the V4L2 and UVC values are
+ * identical.
+ *
+ * For controls of type UVC_CTRL_DATA_TYPE_BITMASK, the UVC control value is
+ * expressed as a bitmask and is thus guaranteed to have a single bit set.
+ *
+ * The function returns -EINVAL if the V4L2 menu index @idx isn't valid for the
+ * control, which includes all controls whose type isn't UVC_CTRL_DATA_TYPE_ENUM
+ * or UVC_CTRL_DATA_TYPE_BITMASK.
+ */
+static int uvc_mapping_get_menu_value(const struct uvc_control_mapping *mapping,
+				      u32 idx)
+{
+	if (!test_bit(idx, &mapping->menu_mask))
+		return -EINVAL;
+
+	if (mapping->menu_mapping)
+		return mapping->menu_mapping[idx];
+
+	return idx;
+}
+
+static const char *
+uvc_mapping_get_menu_name(const struct uvc_control_mapping *mapping, u32 idx)
+{
+	if (!test_bit(idx, &mapping->menu_mask))
+		return NULL;
+
+	if (mapping->menu_names)
+		return mapping->menu_names[idx];
+
+	return v4l2_ctrl_get_menu(mapping->id)[idx];
+}
 
 static s32 uvc_ctrl_get_zoom(struct uvc_control_mapping *mapping,
 	u8 query, const u8 *data)
@@ -525,7 +551,7 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
 		.offset		= 0,
 		.v4l2_type	= V4L2_CTRL_TYPE_MENU,
 		.data_type	= UVC_CTRL_DATA_TYPE_BITMASK,
-		.menu_info	= exposure_auto_controls,
+		.menu_mapping	= exposure_auto_mapping,
 		.menu_mask	= GENMASK(V4L2_EXPOSURE_APERTURE_PRIORITY,
 					  V4L2_EXPOSURE_AUTO),
 		.slave_ids	= { V4L2_CID_EXPOSURE_ABSOLUTE, },
@@ -731,7 +757,6 @@ const struct uvc_control_mapping uvc_ctrl_power_line_mapping_limited = {
 	.offset		= 0,
 	.v4l2_type	= V4L2_CTRL_TYPE_MENU,
 	.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
-	.menu_info	= power_line_frequency_controls,
 	.menu_mask	= GENMASK(V4L2_CID_POWER_LINE_FREQUENCY_60HZ,
 				  V4L2_CID_POWER_LINE_FREQUENCY_50HZ),
 };
@@ -744,7 +769,6 @@ const struct uvc_control_mapping uvc_ctrl_power_line_mapping_uvc11 = {
 	.offset		= 0,
 	.v4l2_type	= V4L2_CTRL_TYPE_MENU,
 	.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
-	.menu_info	= power_line_frequency_controls,
 	.menu_mask	= GENMASK(V4L2_CID_POWER_LINE_FREQUENCY_60HZ,
 				  V4L2_CID_POWER_LINE_FREQUENCY_DISABLED),
 };
@@ -762,7 +786,6 @@ static const struct uvc_control_mapping uvc_ctrl_power_line_mapping_uvc15 = {
 	.offset		= 0,
 	.v4l2_type	= V4L2_CTRL_TYPE_MENU,
 	.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
-	.menu_info	= power_line_frequency_controls,
 	.menu_mask	= GENMASK(V4L2_CID_POWER_LINE_FREQUENCY_AUTO,
 				  V4L2_CID_POWER_LINE_FREQUENCY_DISABLED),
 };
@@ -995,13 +1018,17 @@ static s32 __uvc_ctrl_get_value(struct uvc_control_mapping *mapping,
 	s32 value = mapping->get(mapping, UVC_GET_CUR, data);
 
 	if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
-		const struct uvc_menu_info *menu = mapping->menu_info;
 		unsigned int i;
 
-		for (i = 0; BIT(i) <= mapping->menu_mask; ++i, ++menu) {
+		for (i = 0; BIT(i) <= mapping->menu_mask; ++i) {
+			u32 menu_value;
+
 			if (!test_bit(i, &mapping->menu_mask))
 				continue;
-			if (menu->value == value) {
+
+			menu_value = uvc_mapping_get_menu_value(mapping, i);
+
+			if (menu_value == value) {
 				value = i;
 				break;
 			}
@@ -1212,7 +1239,6 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
 {
 	struct uvc_control_mapping *master_map = NULL;
 	struct uvc_control *master_ctrl = NULL;
-	const struct uvc_menu_info *menu;
 	unsigned int i;
 
 	memset(v4l2_ctrl, 0, sizeof(*v4l2_ctrl));
@@ -1257,11 +1283,15 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
 		v4l2_ctrl->maximum = fls(mapping->menu_mask) - 1;
 		v4l2_ctrl->step = 1;
 
-		menu = mapping->menu_info;
-		for (i = 0; BIT(i) <= mapping->menu_mask; ++i, ++menu) {
+		for (i = 0; BIT(i) <= mapping->menu_mask; ++i) {
+			u32 menu_value;
+
 			if (!test_bit(i, &mapping->menu_mask))
 				continue;
-			if (menu->value == v4l2_ctrl->default_value) {
+
+			menu_value = uvc_mapping_get_menu_value(mapping, i);
+
+			if (menu_value == v4l2_ctrl->default_value) {
 				v4l2_ctrl->default_value = i;
 				break;
 			}
@@ -1360,11 +1390,11 @@ int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
 int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
 	struct v4l2_querymenu *query_menu)
 {
-	const struct uvc_menu_info *menu_info;
 	struct uvc_control_mapping *mapping;
 	struct uvc_control *ctrl;
 	u32 index = query_menu->index;
 	u32 id = query_menu->id;
+	const char *name;
 	int ret;
 
 	memset(query_menu, 0, sizeof(*query_menu));
@@ -1386,22 +1416,34 @@ int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
 		goto done;
 	}
 
-	menu_info = &mapping->menu_info[query_menu->index];
-
 	if (mapping->data_type == UVC_CTRL_DATA_TYPE_BITMASK) {
+		int mask;
+
 		if (!ctrl->cached) {
 			ret = uvc_ctrl_populate_cache(chain, ctrl);
 			if (ret < 0)
 				goto done;
 		}
 
-		if (!(uvc_get_ctrl_bitmap(ctrl, mapping) & menu_info->value)) {
+		mask = uvc_mapping_get_menu_value(mapping, query_menu->index);
+		if (mask < 0) {
+			ret = mask;
+			goto done;
+		}
+
+		if (!(uvc_get_ctrl_bitmap(ctrl, mapping) & mask)) {
 			ret = -EINVAL;
 			goto done;
 		}
 	}
 
-	strscpy(query_menu->name, menu_info->name, sizeof(query_menu->name));
+	name = uvc_mapping_get_menu_name(mapping, query_menu->index);
+	if (!name) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	strscpy(query_menu->name, name, sizeof(query_menu->name));
 
 done:
 	mutex_unlock(&chain->ctrl_mutex);
@@ -1902,7 +1944,7 @@ int uvc_ctrl_set(struct uvc_fh *handle,
 		if (!test_bit(xctrl->value, &mapping->menu_mask))
 			return -EINVAL;
 
-		value = mapping->menu_info[xctrl->value].value;
+		value = uvc_mapping_get_menu_value(mapping, xctrl->value);
 
 		/*
 		 * Valid menu indices are reported by the GET_RES request for
@@ -2327,7 +2369,8 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
 		return -ENOMEM;
 
 	map->name = NULL;
-	map->menu_info = NULL;
+	map->menu_names = NULL;
+	map->menu_mapping = NULL;
 
 	/* For UVCIOC_CTRL_MAP custom control */
 	if (mapping->name) {
@@ -2338,10 +2381,22 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
 
 	INIT_LIST_HEAD(&map->ev_subs);
 
-	size = sizeof(*mapping->menu_info) * fls(mapping->menu_mask);
-	map->menu_info = kmemdup(mapping->menu_info, size, GFP_KERNEL);
-	if (!map->menu_info)
-		goto err_nomem;
+	if (mapping->menu_mapping && mapping->menu_mask) {
+		size = sizeof(mapping->menu_mapping[0])
+		       * fls(mapping->menu_mask);
+		map->menu_mapping = kmemdup(mapping->menu_mapping, size,
+					    GFP_KERNEL);
+		if (!map->menu_mapping)
+			goto err_nomem;
+	}
+	if (mapping->menu_names && mapping->menu_mask) {
+		size = sizeof(mapping->menu_names[0])
+		       * fls(mapping->menu_mask);
+		map->menu_names = kmemdup(mapping->menu_names, size,
+					  GFP_KERNEL);
+		if (!map->menu_names)
+			goto err_nomem;
+	}
 
 	if (map->get == NULL)
 		map->get = uvc_get_le_value;
@@ -2364,7 +2419,8 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
 	return 0;
 
 err_nomem:
-	kfree(map->menu_info);
+	kfree(map->menu_names);
+	kfree(map->menu_mapping);
 	kfree(map->name);
 	kfree(map);
 	return -ENOMEM;
@@ -2689,7 +2745,8 @@ static void uvc_ctrl_cleanup_mappings(struct uvc_device *dev,
 
 	list_for_each_entry_safe(mapping, nm, &ctrl->info.mappings, list) {
 		list_del(&mapping->list);
-		kfree(mapping->menu_info);
+		kfree(mapping->menu_names);
+		kfree(mapping->menu_mapping);
 		kfree(mapping->name);
 		kfree(mapping);
 	}

drivers/media/usb/uvc/uvc_v4l2.c

@@ -26,14 +26,84 @@
 
 #include "uvcvideo.h"
 
+static int uvc_control_add_xu_mapping(struct uvc_video_chain *chain,
+				      struct uvc_control_mapping *map,
+				      const struct uvc_xu_control_mapping *xmap)
+{
+	unsigned int i;
+	size_t size;
+	int ret;
+
+	/*
+	 * Prevent excessive memory consumption, as well as integer
+	 * overflows.
+	 */
+	if (xmap->menu_count == 0 ||
+	    xmap->menu_count > UVC_MAX_CONTROL_MENU_ENTRIES)
+		return -EINVAL;
+
+	map->menu_names = NULL;
+	map->menu_mapping = NULL;
+
+	map->menu_mask = BIT_MASK(xmap->menu_count);
+
+	size = xmap->menu_count * sizeof(*map->menu_mapping);
+	map->menu_mapping = kzalloc(size, GFP_KERNEL);
+	if (!map->menu_mapping) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	for (i = 0; i < xmap->menu_count ; i++) {
+		if (copy_from_user((u32 *)&map->menu_mapping[i],
+				   &xmap->menu_info[i].value,
+				   sizeof(map->menu_mapping[i]))) {
+			ret = -EACCES;
+			goto done;
+		}
+	}
+
+	/*
+	 * Always use the standard naming if available, otherwise copy the
+	 * names supplied by userspace.
+	 */
+	if (!v4l2_ctrl_get_menu(map->id)) {
+		size = xmap->menu_count * sizeof(map->menu_names[0]);
+		map->menu_names = kzalloc(size, GFP_KERNEL);
+		if (!map->menu_names) {
+			ret = -ENOMEM;
+			goto done;
+		}
+
+		for (i = 0; i < xmap->menu_count ; i++) {
+			/* sizeof(names[i]) - 1: to take care of \0 */
+			if (copy_from_user((char *)map->menu_names[i],
+					   xmap->menu_info[i].name,
+					   sizeof(map->menu_names[i]) - 1)) {
+				ret = -EACCES;
+				goto done;
+			}
+		}
+	}
+
+	ret = uvc_ctrl_add_mapping(chain, map);
+
+done:
+	kfree(map->menu_names);
+	map->menu_names = NULL;
+	kfree(map->menu_mapping);
+	map->menu_mapping = NULL;
+
+	return ret;
+}
+
 /* ------------------------------------------------------------------------
  * UVC ioctls
  */
-static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
-	struct uvc_xu_control_mapping *xmap)
+static int uvc_ioctl_xu_ctrl_map(struct uvc_video_chain *chain,
+				 struct uvc_xu_control_mapping *xmap)
 {
 	struct uvc_control_mapping *map;
-	unsigned int size;
 	int ret;
 
 	map = kzalloc(sizeof(*map), GFP_KERNEL);
@@ -61,39 +131,20 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
 	case V4L2_CTRL_TYPE_INTEGER:
 	case V4L2_CTRL_TYPE_BOOLEAN:
 	case V4L2_CTRL_TYPE_BUTTON:
+		ret = uvc_ctrl_add_mapping(chain, map);
 		break;
 
 	case V4L2_CTRL_TYPE_MENU:
-		/*
-		 * Prevent excessive memory consumption, as well as integer
-		 * overflows.
-		 */
-		if (xmap->menu_count == 0 ||
-		    xmap->menu_count > UVC_MAX_CONTROL_MENU_ENTRIES) {
-			ret = -EINVAL;
-			goto free_map;
-		}
-
-		size = xmap->menu_count * sizeof(*map->menu_info);
-		map->menu_info = memdup_user(xmap->menu_info, size);
-		if (IS_ERR(map->menu_info)) {
-			ret = PTR_ERR(map->menu_info);
-			goto free_map;
-		}
-
-		map->menu_mask = GENMASK(xmap->menu_count - 1, 0);
+		ret = uvc_control_add_xu_mapping(chain, map, xmap);
 		break;
 
 	default:
 		uvc_dbg(chain->dev, CONTROL,
 			"Unsupported V4L2 control type %u\n", xmap->v4l2_type);
 		ret = -ENOTTY;
-		goto free_map;
+		break;
 	}
 
-	ret = uvc_ctrl_add_mapping(chain, map);
-
-	kfree(map->menu_info);
 free_map:
 	kfree(map);
 
@@ -1314,7 +1365,7 @@ static long uvc_ioctl_default(struct file *file, void *fh, bool valid_prio,
 	switch (cmd) {
 	/* Dynamic controls. */
 	case UVCIOC_CTRL_MAP:
-		return uvc_ioctl_ctrl_map(chain, arg);
+		return uvc_ioctl_xu_ctrl_map(chain, arg);
 
 	case UVCIOC_CTRL_QUERY:
 		return uvc_xu_ctrl_query(chain, arg);
@@ -1427,7 +1478,7 @@ static long uvc_v4l2_compat_ioctl32(struct file *file,
 		ret = uvc_v4l2_get_xu_mapping(&karg.xmap, up);
 		if (ret)
 			return ret;
-		ret = uvc_ioctl_ctrl_map(handle->chain, &karg.xmap);
+		ret = uvc_ioctl_xu_ctrl_map(handle->chain, &karg.xmap);
 		if (ret)
 			return ret;
 		ret = uvc_v4l2_put_xu_mapping(&karg.xmap, up);

drivers/media/usb/uvc/uvcvideo.h

@@ -114,7 +114,8 @@ struct uvc_control_mapping {
 	enum v4l2_ctrl_type v4l2_type;
 	u32 data_type;
 
-	const struct uvc_menu_info *menu_info;
+	const u32 *menu_mapping;
+	const char (*menu_names)[UVC_MENU_NAME_LEN];
 	unsigned long menu_mask;
 
 	u32 master_id;

include/uapi/linux/uvcvideo.h

@@ -36,9 +36,11 @@
 	 UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES | \
 	 UVC_CTRL_FLAG_GET_DEF)
 
+#define UVC_MENU_NAME_LEN 32
+
 struct uvc_menu_info {
 	__u32 value;
-	__u8 name[32];
+	__u8 name[UVC_MENU_NAME_LEN];
 };
 
 struct uvc_xu_control_mapping {