Fetch the orientation from the fwnode and map it into a control.

The uvc driver does not use the media controller, so we need to create a
virtual entity, like we previously did with the external gpio.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/Makefile     |  2 +-
 drivers/media/usb/uvc/uvc_ctrl.c   | 21 +++++++++++
 drivers/media/usb/uvc/uvc_driver.c | 14 ++++++--
 drivers/media/usb/uvc/uvc_entity.c |  1 +
 drivers/media/usb/uvc/uvc_fwnode.c | 73 ++++++++++++++++++++++++++++++++++++++
 drivers/media/usb/uvc/uvcvideo.h   | 15 ++++++++
 include/linux/usb/uvc.h            |  3 ++
 7 files changed, 125 insertions(+), 4 deletions(-)

diff --git a/drivers/media/usb/uvc/Makefile b/drivers/media/usb/uvc/Makefile
index 85514b6e538fbb8284e574ca14700f2d749e1a2e..2a5b76aab756c21011d966f3ce0410ff6b8e5b19 100644
--- a/drivers/media/usb/uvc/Makefile
+++ b/drivers/media/usb/uvc/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 uvcvideo-objs  := uvc_driver.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_ctrl.o \
 		  uvc_status.o uvc_isight.o uvc_debugfs.o uvc_metadata.o \
-		  uvc_gpio.o
+		  uvc_gpio.o uvc_fwnode.o
 ifeq ($(CONFIG_MEDIA_CONTROLLER),y)
 uvcvideo-objs  += uvc_entity.o
 endif
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index cbf19aa1d82374a08cf79b6a6787fa348b83523a..df84bf292dcab6b833fbd3c70eccbe9e567ee567 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -376,6 +376,13 @@ static const struct uvc_control_info uvc_ctrls[] = {
 				| UVC_CTRL_FLAG_GET_DEF
 				| UVC_CTRL_FLAG_AUTO_UPDATE,
 	},
+	{
+		.entity		= UVC_GUID_FWNODE,
+		.selector	= 0,
+		.index		= 0,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_GET_CUR,
+	},
 };
 
 static const u32 uvc_control_classes[] = {
@@ -975,6 +982,17 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
 		.data_type	= UVC_CTRL_DATA_TYPE_BITMASK,
 		.name		= "Region of Interest Auto Ctrls",
 	},
+	{
+		.id		= V4L2_CID_CAMERA_ORIENTATION,
+		.entity		= UVC_GUID_FWNODE,
+		.selector	= 0,
+		.size		= 8,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_MENU,
+		.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
+		.menu_mask	= GENMASK(V4L2_CAMERA_ORIENTATION_EXTERNAL,
+					  V4L2_CAMERA_ORIENTATION_FRONT),
+	},
 };
 
 /* ------------------------------------------------------------------------
@@ -3170,6 +3188,9 @@ static int uvc_ctrl_init_chain(struct uvc_video_chain *chain)
 		} else if (UVC_ENTITY_TYPE(entity) == UVC_EXT_GPIO_UNIT) {
 			bmControls = entity->gpio.bmControls;
 			bControlSize = entity->gpio.bControlSize;
+		} else if (UVC_ENTITY_TYPE(entity) == UVC_FWNODE_UNIT) {
+			bmControls = entity->fwnode.bmControls;
+			bControlSize = entity->fwnode.bControlSize;
 		}
 
 		/* Remove bogus/blacklisted controls */
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index b52e1ff401e24f69b867b5e975cda4260463e760..9a8e5d94b3eba09e1ee1be20bad5b016b6def915 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1752,11 +1752,15 @@ static int uvc_scan_device(struct uvc_device *dev)
 		return -1;
 	}
 
-	/* Add GPIO entity to the first chain. */
-	if (dev->gpio_unit) {
+	/* Add virtual entities to the first chain. */
+	if (dev->gpio_unit || dev->fwnode_unit) {
 		chain = list_first_entry(&dev->chains,
 					 struct uvc_video_chain, list);
-		list_add_tail(&dev->gpio_unit->chain, &chain->entities);
+		if (dev->gpio_unit)
+			list_add_tail(&dev->gpio_unit->chain, &chain->entities);
+		if (dev->fwnode_unit)
+			list_add_tail(&dev->fwnode_unit->chain,
+				      &chain->entities);
 	}
 
 	return 0;
@@ -2132,6 +2136,10 @@ static int uvc_probe(struct usb_interface *intf,
 	if (ret < 0)
 		goto error;
 
+	ret = uvc_fwnode_parse(dev);
+	if (ret < 0)
+		goto error;
+
 	dev_info(&dev->udev->dev, "Found UVC %u.%02x device %s (%04x:%04x)\n",
 		 dev->uvc_version >> 8, dev->uvc_version & 0xff,
 		 udev->product ? udev->product : "<unnamed>",
diff --git a/drivers/media/usb/uvc/uvc_entity.c b/drivers/media/usb/uvc/uvc_entity.c
index cc68dd24eb42dce5b2846ca52a8dfa499c8aed96..01eeba2f049e9ebb25e091340a133656acbf28ca 100644
--- a/drivers/media/usb/uvc/uvc_entity.c
+++ b/drivers/media/usb/uvc/uvc_entity.c
@@ -106,6 +106,7 @@ static int uvc_mc_init_entity(struct uvc_video_chain *chain,
 		case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
 		case UVC_EXTERNAL_VENDOR_SPECIFIC:
 		case UVC_EXT_GPIO_UNIT:
+		case UVC_FWNODE_UNIT:
 		default:
 			function = MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN;
 			break;
diff --git a/drivers/media/usb/uvc/uvc_fwnode.c b/drivers/media/usb/uvc/uvc_fwnode.c
new file mode 100644
index 0000000000000000000000000000000000000000..20f7b8847551acfd44cbf09bcbf653d89985561f
--- /dev/null
+++ b/drivers/media/usb/uvc/uvc_fwnode.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *      uvc_fwnode.c  --  USB Video Class driver
+ *
+ *      Copyright 2025 Google LLC
+ */
+
+#include <linux/kernel.h>
+#include <linux/usb/uvc.h>
+#include <media/v4l2-fwnode.h>
+#include "uvcvideo.h"
+
+static int uvc_fwnode_get_cur(struct uvc_device *dev, struct uvc_entity *entity,
+			      u8 cs, void *data, u16 size)
+{
+	if (size < 1)
+		return -EINVAL;
+
+	switch (entity->fwnode.props.orientation) {
+	case V4L2_FWNODE_ORIENTATION_FRONT:
+		*(u8 *)data = V4L2_CAMERA_ORIENTATION_FRONT;
+		break;
+	case V4L2_FWNODE_ORIENTATION_BACK:
+		*(u8 *)data = V4L2_CAMERA_ORIENTATION_BACK;
+		break;
+	default:
+		*(u8 *)data = V4L2_CAMERA_ORIENTATION_EXTERNAL;
+	}
+
+	return 0;
+}
+
+static int uvc_fwnode_get_info(struct uvc_device *dev,
+			       struct uvc_entity *entity, u8 cs, u8 *caps)
+{
+	*caps = UVC_CONTROL_CAP_GET;
+	return 0;
+}
+
+int uvc_fwnode_parse(struct uvc_device *dev)
+{
+	static const u8 uvc_fwnode_guid[] = UVC_GUID_FWNODE;
+	struct v4l2_fwnode_device_properties props;
+	struct uvc_entity *unit;
+	int ret;
+
+	ret = v4l2_fwnode_device_parse(&dev->udev->dev, &props);
+	if (ret)
+		return dev_err_probe(&dev->intf->dev, ret,
+				     "Can't parse fwnode\n");
+
+	if (props.orientation == V4L2_FWNODE_PROPERTY_UNSET)
+		return 0;
+
+	unit = uvc_alloc_entity(UVC_FWNODE_UNIT, UVC_FWNODE_UNIT_ID, 0, 1);
+	if (!unit)
+		return -ENOMEM;
+
+	memcpy(unit->guid, uvc_fwnode_guid, sizeof(unit->guid));
+	unit->fwnode.props = props;
+	unit->fwnode.bControlSize = 1;
+	unit->fwnode.bmControls = (u8 *)unit + sizeof(*unit);
+	unit->fwnode.bmControls[0] = 1;
+	unit->get_cur = uvc_fwnode_get_cur;
+	unit->get_info = uvc_fwnode_get_info;
+	strscpy(unit->name, "FWNODE", sizeof(unit->name));
+
+	list_add_tail(&unit->list, &dev->entities);
+
+	dev->fwnode_unit = unit;
+
+	return 0;
+}
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index aef96b96499ce09ffa286c51793482afd9832097..c52ab99bf8d21ab37270d27ffc040fd115b3f5ba 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -19,6 +19,7 @@
 #include <media/v4l2-event.h>
 #include <media/v4l2-fh.h>
 #include <media/videobuf2-v4l2.h>
+#include <media/v4l2-fwnode.h>
 
 /* --------------------------------------------------------------------------
  * UVC constants
@@ -41,6 +42,9 @@
 #define UVC_EXT_GPIO_UNIT		0x7ffe
 #define UVC_EXT_GPIO_UNIT_ID		0x100
 
+#define UVC_FWNODE_UNIT			0x7ffd
+#define UVC_FWNODE_UNIT_ID		0x101
+
 /* ------------------------------------------------------------------------
  * Driver specific constants.
  */
@@ -242,6 +246,12 @@ struct uvc_entity {
 			int irq;
 			bool initialized;
 		} gpio;
+
+		struct {
+			u8  bControlSize;
+			u8  *bmControls;
+			struct v4l2_fwnode_device_properties props;
+		} fwnode;
 	};
 
 	u8 bNrInPins;
@@ -617,6 +627,7 @@ struct uvc_device {
 	} async_ctrl;
 
 	struct uvc_entity *gpio_unit;
+	struct uvc_entity *fwnode_unit;
 };
 
 enum uvc_handle_state {
@@ -835,4 +846,8 @@ size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf,
 int uvc_gpio_parse(struct uvc_device *dev);
 int uvc_gpio_init_irq(struct uvc_device *dev);
 void uvc_gpio_deinit(struct uvc_device *dev);
+
+/* fwnode */
+int uvc_fwnode_parse(struct uvc_device *dev);
+
 #endif
diff --git a/include/linux/usb/uvc.h b/include/linux/usb/uvc.h
index bce95153e5a65613a710d7316fc17cf5462b5bce..d818839b0442988d94ab44935e1ce855b0adf4a1 100644
--- a/include/linux/usb/uvc.h
+++ b/include/linux/usb/uvc.h
@@ -29,6 +29,9 @@
 #define UVC_GUID_EXT_GPIO_CONTROLLER \
 	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
 	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x03}
+#define UVC_GUID_FWNODE \
+	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x04}
 
 #define UVC_GUID_FORMAT_MJPEG \
 	{ 'M',  'J',  'P',  'G', 0x00, 0x00, 0x10, 0x00, \

-- 
2.49.0.504.g3bcea36a83-goog

Hi Ricardo,

Thank you for the patch.

On Thu, Apr 03, 2025 at 07:16:18PM +0000, Ricardo Ribalda wrote:
> Fetch the orientation from the fwnode and map it into a control.
> 
> The uvc driver does not use the media controller, so we need to create a
> virtual entity, like we previously did with the external gpio.

I don't want to create a new entity every time we need to expose a new
"software" control. If we keep handling GPIO as an entity, can we use it
to expose all non-UVC controls ? Otherwise, if we have to create a new
entity here, let's make sure we can reuse it in the future for more
controls, and name it appropriately.

This being said, functionally speaking, wouldn't the
V4L2_CID_CAMERA_ORIENTATION control make more sense on the camera input
terminal ? Have you considered adding it there ? Or would it be too
intrusive ?

> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/usb/uvc/Makefile     |  2 +-
>  drivers/media/usb/uvc/uvc_ctrl.c   | 21 +++++++++++
>  drivers/media/usb/uvc/uvc_driver.c | 14 ++++++--
>  drivers/media/usb/uvc/uvc_entity.c |  1 +
>  drivers/media/usb/uvc/uvc_fwnode.c | 73 ++++++++++++++++++++++++++++++++++++++
>  drivers/media/usb/uvc/uvcvideo.h   | 15 ++++++++
>  include/linux/usb/uvc.h            |  3 ++
>  7 files changed, 125 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/Makefile b/drivers/media/usb/uvc/Makefile
> index 85514b6e538fbb8284e574ca14700f2d749e1a2e..2a5b76aab756c21011d966f3ce0410ff6b8e5b19 100644
> --- a/drivers/media/usb/uvc/Makefile
> +++ b/drivers/media/usb/uvc/Makefile
> @@ -1,7 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0
>  uvcvideo-objs  := uvc_driver.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_ctrl.o \
>  		  uvc_status.o uvc_isight.o uvc_debugfs.o uvc_metadata.o \
> -		  uvc_gpio.o
> +		  uvc_gpio.o uvc_fwnode.o
>  ifeq ($(CONFIG_MEDIA_CONTROLLER),y)
>  uvcvideo-objs  += uvc_entity.o
>  endif
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index cbf19aa1d82374a08cf79b6a6787fa348b83523a..df84bf292dcab6b833fbd3c70eccbe9e567ee567 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -376,6 +376,13 @@ static const struct uvc_control_info uvc_ctrls[] = {
>  				| UVC_CTRL_FLAG_GET_DEF
>  				| UVC_CTRL_FLAG_AUTO_UPDATE,
>  	},
> +	{
> +		.entity		= UVC_GUID_FWNODE,
> +		.selector	= 0,
> +		.index		= 0,
> +		.size		= 1,
> +		.flags		= UVC_CTRL_FLAG_GET_CUR,
> +	},
>  };
>  
>  static const u32 uvc_control_classes[] = {
> @@ -975,6 +982,17 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
>  		.data_type	= UVC_CTRL_DATA_TYPE_BITMASK,
>  		.name		= "Region of Interest Auto Ctrls",
>  	},
> +	{
> +		.id		= V4L2_CID_CAMERA_ORIENTATION,
> +		.entity		= UVC_GUID_FWNODE,
> +		.selector	= 0,
> +		.size		= 8,
> +		.offset		= 0,
> +		.v4l2_type	= V4L2_CTRL_TYPE_MENU,
> +		.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
> +		.menu_mask	= GENMASK(V4L2_CAMERA_ORIENTATION_EXTERNAL,
> +					  V4L2_CAMERA_ORIENTATION_FRONT),
> +	},
>  };
>  
>  /* ------------------------------------------------------------------------
> @@ -3170,6 +3188,9 @@ static int uvc_ctrl_init_chain(struct uvc_video_chain *chain)
>  		} else if (UVC_ENTITY_TYPE(entity) == UVC_EXT_GPIO_UNIT) {
>  			bmControls = entity->gpio.bmControls;
>  			bControlSize = entity->gpio.bControlSize;
> +		} else if (UVC_ENTITY_TYPE(entity) == UVC_FWNODE_UNIT) {
> +			bmControls = entity->fwnode.bmControls;
> +			bControlSize = entity->fwnode.bControlSize;
>  		}
>  
>  		/* Remove bogus/blacklisted controls */
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index b52e1ff401e24f69b867b5e975cda4260463e760..9a8e5d94b3eba09e1ee1be20bad5b016b6def915 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1752,11 +1752,15 @@ static int uvc_scan_device(struct uvc_device *dev)
>  		return -1;
>  	}
>  
> -	/* Add GPIO entity to the first chain. */
> -	if (dev->gpio_unit) {
> +	/* Add virtual entities to the first chain. */
> +	if (dev->gpio_unit || dev->fwnode_unit) {
>  		chain = list_first_entry(&dev->chains,
>  					 struct uvc_video_chain, list);
> -		list_add_tail(&dev->gpio_unit->chain, &chain->entities);
> +		if (dev->gpio_unit)
> +			list_add_tail(&dev->gpio_unit->chain, &chain->entities);
> +		if (dev->fwnode_unit)
> +			list_add_tail(&dev->fwnode_unit->chain,
> +				      &chain->entities);
>  	}
>  
>  	return 0;
> @@ -2132,6 +2136,10 @@ static int uvc_probe(struct usb_interface *intf,
>  	if (ret < 0)
>  		goto error;
>  
> +	ret = uvc_fwnode_parse(dev);
> +	if (ret < 0)
> +		goto error;
> +
>  	dev_info(&dev->udev->dev, "Found UVC %u.%02x device %s (%04x:%04x)\n",
>  		 dev->uvc_version >> 8, dev->uvc_version & 0xff,
>  		 udev->product ? udev->product : "<unnamed>",
> diff --git a/drivers/media/usb/uvc/uvc_entity.c b/drivers/media/usb/uvc/uvc_entity.c
> index cc68dd24eb42dce5b2846ca52a8dfa499c8aed96..01eeba2f049e9ebb25e091340a133656acbf28ca 100644
> --- a/drivers/media/usb/uvc/uvc_entity.c
> +++ b/drivers/media/usb/uvc/uvc_entity.c
> @@ -106,6 +106,7 @@ static int uvc_mc_init_entity(struct uvc_video_chain *chain,
>  		case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
>  		case UVC_EXTERNAL_VENDOR_SPECIFIC:
>  		case UVC_EXT_GPIO_UNIT:
> +		case UVC_FWNODE_UNIT:
>  		default:
>  			function = MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN;
>  			break;
> diff --git a/drivers/media/usb/uvc/uvc_fwnode.c b/drivers/media/usb/uvc/uvc_fwnode.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..20f7b8847551acfd44cbf09bcbf653d89985561f
> --- /dev/null
> +++ b/drivers/media/usb/uvc/uvc_fwnode.c
> @@ -0,0 +1,73 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + *      uvc_fwnode.c  --  USB Video Class driver
> + *
> + *      Copyright 2025 Google LLC
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/usb/uvc.h>
> +#include <media/v4l2-fwnode.h>
> +#include "uvcvideo.h"
> +
> +static int uvc_fwnode_get_cur(struct uvc_device *dev, struct uvc_entity *entity,
> +			      u8 cs, void *data, u16 size)
> +{
> +	if (size < 1)
> +		return -EINVAL;
> +
> +	switch (entity->fwnode.props.orientation) {
> +	case V4L2_FWNODE_ORIENTATION_FRONT:
> +		*(u8 *)data = V4L2_CAMERA_ORIENTATION_FRONT;
> +		break;
> +	case V4L2_FWNODE_ORIENTATION_BACK:
> +		*(u8 *)data = V4L2_CAMERA_ORIENTATION_BACK;
> +		break;
> +	default:
> +		*(u8 *)data = V4L2_CAMERA_ORIENTATION_EXTERNAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int uvc_fwnode_get_info(struct uvc_device *dev,
> +			       struct uvc_entity *entity, u8 cs, u8 *caps)
> +{
> +	*caps = UVC_CONTROL_CAP_GET;
> +	return 0;
> +}
> +
> +int uvc_fwnode_parse(struct uvc_device *dev)
> +{
> +	static const u8 uvc_fwnode_guid[] = UVC_GUID_FWNODE;
> +	struct v4l2_fwnode_device_properties props;
> +	struct uvc_entity *unit;
> +	int ret;
> +
> +	ret = v4l2_fwnode_device_parse(&dev->udev->dev, &props);
> +	if (ret)
> +		return dev_err_probe(&dev->intf->dev, ret,
> +				     "Can't parse fwnode\n");
> +
> +	if (props.orientation == V4L2_FWNODE_PROPERTY_UNSET)
> +		return 0;
> +
> +	unit = uvc_alloc_entity(UVC_FWNODE_UNIT, UVC_FWNODE_UNIT_ID, 0, 1);
> +	if (!unit)
> +		return -ENOMEM;
> +
> +	memcpy(unit->guid, uvc_fwnode_guid, sizeof(unit->guid));
> +	unit->fwnode.props = props;
> +	unit->fwnode.bControlSize = 1;
> +	unit->fwnode.bmControls = (u8 *)unit + sizeof(*unit);
> +	unit->fwnode.bmControls[0] = 1;
> +	unit->get_cur = uvc_fwnode_get_cur;
> +	unit->get_info = uvc_fwnode_get_info;
> +	strscpy(unit->name, "FWNODE", sizeof(unit->name));
> +
> +	list_add_tail(&unit->list, &dev->entities);
> +
> +	dev->fwnode_unit = unit;
> +
> +	return 0;
> +}
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index aef96b96499ce09ffa286c51793482afd9832097..c52ab99bf8d21ab37270d27ffc040fd115b3f5ba 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -19,6 +19,7 @@
>  #include <media/v4l2-event.h>
>  #include <media/v4l2-fh.h>
>  #include <media/videobuf2-v4l2.h>
> +#include <media/v4l2-fwnode.h>
>  
>  /* --------------------------------------------------------------------------
>   * UVC constants
> @@ -41,6 +42,9 @@
>  #define UVC_EXT_GPIO_UNIT		0x7ffe
>  #define UVC_EXT_GPIO_UNIT_ID		0x100
>  
> +#define UVC_FWNODE_UNIT			0x7ffd
> +#define UVC_FWNODE_UNIT_ID		0x101
> +
>  /* ------------------------------------------------------------------------
>   * Driver specific constants.
>   */
> @@ -242,6 +246,12 @@ struct uvc_entity {
>  			int irq;
>  			bool initialized;
>  		} gpio;
> +
> +		struct {
> +			u8  bControlSize;
> +			u8  *bmControls;
> +			struct v4l2_fwnode_device_properties props;
> +		} fwnode;
>  	};
>  
>  	u8 bNrInPins;
> @@ -617,6 +627,7 @@ struct uvc_device {
>  	} async_ctrl;
>  
>  	struct uvc_entity *gpio_unit;
> +	struct uvc_entity *fwnode_unit;
>  };
>  
>  enum uvc_handle_state {
> @@ -835,4 +846,8 @@ size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf,
>  int uvc_gpio_parse(struct uvc_device *dev);
>  int uvc_gpio_init_irq(struct uvc_device *dev);
>  void uvc_gpio_deinit(struct uvc_device *dev);
> +
> +/* fwnode */
> +int uvc_fwnode_parse(struct uvc_device *dev);
> +
>  #endif
> diff --git a/include/linux/usb/uvc.h b/include/linux/usb/uvc.h
> index bce95153e5a65613a710d7316fc17cf5462b5bce..d818839b0442988d94ab44935e1ce855b0adf4a1 100644
> --- a/include/linux/usb/uvc.h
> +++ b/include/linux/usb/uvc.h
> @@ -29,6 +29,9 @@
>  #define UVC_GUID_EXT_GPIO_CONTROLLER \
>  	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
>  	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x03}
> +#define UVC_GUID_FWNODE \
> +	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
> +	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x04}
>  
>  #define UVC_GUID_FORMAT_MJPEG \
>  	{ 'M',  'J',  'P',  'G', 0x00, 0x00, 0x10, 0x00, \
> 
> -- 
> 2.49.0.504.g3bcea36a83-goog
> 

-- 
Regards,

Laurent Pinchart

On Wed, Apr 23, 2025 at 12:32:37AM +0300, Laurent Pinchart wrote:
> Hi Ricardo,
> 
> Thank you for the patch.
> 
> On Thu, Apr 03, 2025 at 07:16:18PM +0000, Ricardo Ribalda wrote:
> > Fetch the orientation from the fwnode and map it into a control.
> > 
> > The uvc driver does not use the media controller, so we need to create a
> > virtual entity, like we previously did with the external gpio.
> 
> I don't want to create a new entity every time we need to expose a new
> "software" control. If we keep handling GPIO as an entity, can we use it
> to expose all non-UVC controls ? Otherwise, if we have to create a new
> entity here, let's make sure we can reuse it in the future for more
> controls, and name it appropriately.
> 
> This being said, functionally speaking, wouldn't the
> V4L2_CID_CAMERA_ORIENTATION control make more sense on the camera input
> terminal ? Have you considered adding it there ? Or would it be too
> intrusive ?

Scratch the last comment, I was thinking about exposing controls on
subdevs, which we obviously don't do.

> > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> > ---
> >  drivers/media/usb/uvc/Makefile     |  2 +-
> >  drivers/media/usb/uvc/uvc_ctrl.c   | 21 +++++++++++
> >  drivers/media/usb/uvc/uvc_driver.c | 14 ++++++--
> >  drivers/media/usb/uvc/uvc_entity.c |  1 +
> >  drivers/media/usb/uvc/uvc_fwnode.c | 73 ++++++++++++++++++++++++++++++++++++++
> >  drivers/media/usb/uvc/uvcvideo.h   | 15 ++++++++
> >  include/linux/usb/uvc.h            |  3 ++
> >  7 files changed, 125 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/media/usb/uvc/Makefile b/drivers/media/usb/uvc/Makefile
> > index 85514b6e538fbb8284e574ca14700f2d749e1a2e..2a5b76aab756c21011d966f3ce0410ff6b8e5b19 100644
> > --- a/drivers/media/usb/uvc/Makefile
> > +++ b/drivers/media/usb/uvc/Makefile
> > @@ -1,7 +1,7 @@
> >  # SPDX-License-Identifier: GPL-2.0
> >  uvcvideo-objs  := uvc_driver.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_ctrl.o \
> >  		  uvc_status.o uvc_isight.o uvc_debugfs.o uvc_metadata.o \
> > -		  uvc_gpio.o
> > +		  uvc_gpio.o uvc_fwnode.o
> >  ifeq ($(CONFIG_MEDIA_CONTROLLER),y)
> >  uvcvideo-objs  += uvc_entity.o
> >  endif
> > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> > index cbf19aa1d82374a08cf79b6a6787fa348b83523a..df84bf292dcab6b833fbd3c70eccbe9e567ee567 100644
> > --- a/drivers/media/usb/uvc/uvc_ctrl.c
> > +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> > @@ -376,6 +376,13 @@ static const struct uvc_control_info uvc_ctrls[] = {
> >  				| UVC_CTRL_FLAG_GET_DEF
> >  				| UVC_CTRL_FLAG_AUTO_UPDATE,
> >  	},
> > +	{
> > +		.entity		= UVC_GUID_FWNODE,
> > +		.selector	= 0,
> > +		.index		= 0,
> > +		.size		= 1,
> > +		.flags		= UVC_CTRL_FLAG_GET_CUR,
> > +	},
> >  };
> >  
> >  static const u32 uvc_control_classes[] = {
> > @@ -975,6 +982,17 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
> >  		.data_type	= UVC_CTRL_DATA_TYPE_BITMASK,
> >  		.name		= "Region of Interest Auto Ctrls",
> >  	},
> > +	{
> > +		.id		= V4L2_CID_CAMERA_ORIENTATION,
> > +		.entity		= UVC_GUID_FWNODE,
> > +		.selector	= 0,
> > +		.size		= 8,
> > +		.offset		= 0,
> > +		.v4l2_type	= V4L2_CTRL_TYPE_MENU,
> > +		.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
> > +		.menu_mask	= GENMASK(V4L2_CAMERA_ORIENTATION_EXTERNAL,
> > +					  V4L2_CAMERA_ORIENTATION_FRONT),
> > +	},
> >  };
> >  
> >  /* ------------------------------------------------------------------------
> > @@ -3170,6 +3188,9 @@ static int uvc_ctrl_init_chain(struct uvc_video_chain *chain)
> >  		} else if (UVC_ENTITY_TYPE(entity) == UVC_EXT_GPIO_UNIT) {
> >  			bmControls = entity->gpio.bmControls;
> >  			bControlSize = entity->gpio.bControlSize;
> > +		} else if (UVC_ENTITY_TYPE(entity) == UVC_FWNODE_UNIT) {
> > +			bmControls = entity->fwnode.bmControls;
> > +			bControlSize = entity->fwnode.bControlSize;
> >  		}
> >  
> >  		/* Remove bogus/blacklisted controls */
> > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> > index b52e1ff401e24f69b867b5e975cda4260463e760..9a8e5d94b3eba09e1ee1be20bad5b016b6def915 100644
> > --- a/drivers/media/usb/uvc/uvc_driver.c
> > +++ b/drivers/media/usb/uvc/uvc_driver.c
> > @@ -1752,11 +1752,15 @@ static int uvc_scan_device(struct uvc_device *dev)
> >  		return -1;
> >  	}
> >  
> > -	/* Add GPIO entity to the first chain. */
> > -	if (dev->gpio_unit) {
> > +	/* Add virtual entities to the first chain. */
> > +	if (dev->gpio_unit || dev->fwnode_unit) {
> >  		chain = list_first_entry(&dev->chains,
> >  					 struct uvc_video_chain, list);
> > -		list_add_tail(&dev->gpio_unit->chain, &chain->entities);
> > +		if (dev->gpio_unit)
> > +			list_add_tail(&dev->gpio_unit->chain, &chain->entities);
> > +		if (dev->fwnode_unit)
> > +			list_add_tail(&dev->fwnode_unit->chain,
> > +				      &chain->entities);
> >  	}
> >  
> >  	return 0;
> > @@ -2132,6 +2136,10 @@ static int uvc_probe(struct usb_interface *intf,
> >  	if (ret < 0)
> >  		goto error;
> >  
> > +	ret = uvc_fwnode_parse(dev);
> > +	if (ret < 0)
> > +		goto error;
> > +
> >  	dev_info(&dev->udev->dev, "Found UVC %u.%02x device %s (%04x:%04x)\n",
> >  		 dev->uvc_version >> 8, dev->uvc_version & 0xff,
> >  		 udev->product ? udev->product : "<unnamed>",
> > diff --git a/drivers/media/usb/uvc/uvc_entity.c b/drivers/media/usb/uvc/uvc_entity.c
> > index cc68dd24eb42dce5b2846ca52a8dfa499c8aed96..01eeba2f049e9ebb25e091340a133656acbf28ca 100644
> > --- a/drivers/media/usb/uvc/uvc_entity.c
> > +++ b/drivers/media/usb/uvc/uvc_entity.c
> > @@ -106,6 +106,7 @@ static int uvc_mc_init_entity(struct uvc_video_chain *chain,
> >  		case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
> >  		case UVC_EXTERNAL_VENDOR_SPECIFIC:
> >  		case UVC_EXT_GPIO_UNIT:
> > +		case UVC_FWNODE_UNIT:
> >  		default:
> >  			function = MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN;
> >  			break;
> > diff --git a/drivers/media/usb/uvc/uvc_fwnode.c b/drivers/media/usb/uvc/uvc_fwnode.c
> > new file mode 100644
> > index 0000000000000000000000000000000000000000..20f7b8847551acfd44cbf09bcbf653d89985561f
> > --- /dev/null
> > +++ b/drivers/media/usb/uvc/uvc_fwnode.c
> > @@ -0,0 +1,73 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + *      uvc_fwnode.c  --  USB Video Class driver
> > + *
> > + *      Copyright 2025 Google LLC
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/usb/uvc.h>
> > +#include <media/v4l2-fwnode.h>
> > +#include "uvcvideo.h"
> > +
> > +static int uvc_fwnode_get_cur(struct uvc_device *dev, struct uvc_entity *entity,
> > +			      u8 cs, void *data, u16 size)
> > +{
> > +	if (size < 1)
> > +		return -EINVAL;
> > +
> > +	switch (entity->fwnode.props.orientation) {
> > +	case V4L2_FWNODE_ORIENTATION_FRONT:
> > +		*(u8 *)data = V4L2_CAMERA_ORIENTATION_FRONT;
> > +		break;
> > +	case V4L2_FWNODE_ORIENTATION_BACK:
> > +		*(u8 *)data = V4L2_CAMERA_ORIENTATION_BACK;
> > +		break;
> > +	default:
> > +		*(u8 *)data = V4L2_CAMERA_ORIENTATION_EXTERNAL;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int uvc_fwnode_get_info(struct uvc_device *dev,
> > +			       struct uvc_entity *entity, u8 cs, u8 *caps)
> > +{
> > +	*caps = UVC_CONTROL_CAP_GET;
> > +	return 0;
> > +}
> > +
> > +int uvc_fwnode_parse(struct uvc_device *dev)
> > +{
> > +	static const u8 uvc_fwnode_guid[] = UVC_GUID_FWNODE;
> > +	struct v4l2_fwnode_device_properties props;
> > +	struct uvc_entity *unit;
> > +	int ret;
> > +
> > +	ret = v4l2_fwnode_device_parse(&dev->udev->dev, &props);
> > +	if (ret)
> > +		return dev_err_probe(&dev->intf->dev, ret,
> > +				     "Can't parse fwnode\n");
> > +
> > +	if (props.orientation == V4L2_FWNODE_PROPERTY_UNSET)
> > +		return 0;
> > +
> > +	unit = uvc_alloc_entity(UVC_FWNODE_UNIT, UVC_FWNODE_UNIT_ID, 0, 1);
> > +	if (!unit)
> > +		return -ENOMEM;
> > +
> > +	memcpy(unit->guid, uvc_fwnode_guid, sizeof(unit->guid));
> > +	unit->fwnode.props = props;
> > +	unit->fwnode.bControlSize = 1;
> > +	unit->fwnode.bmControls = (u8 *)unit + sizeof(*unit);
> > +	unit->fwnode.bmControls[0] = 1;
> > +	unit->get_cur = uvc_fwnode_get_cur;
> > +	unit->get_info = uvc_fwnode_get_info;
> > +	strscpy(unit->name, "FWNODE", sizeof(unit->name));
> > +
> > +	list_add_tail(&unit->list, &dev->entities);
> > +
> > +	dev->fwnode_unit = unit;
> > +
> > +	return 0;
> > +}
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index aef96b96499ce09ffa286c51793482afd9832097..c52ab99bf8d21ab37270d27ffc040fd115b3f5ba 100644
> > --- a/drivers/media/usb/uvc/uvcvideo.h
> > +++ b/drivers/media/usb/uvc/uvcvideo.h
> > @@ -19,6 +19,7 @@
> >  #include <media/v4l2-event.h>
> >  #include <media/v4l2-fh.h>
> >  #include <media/videobuf2-v4l2.h>
> > +#include <media/v4l2-fwnode.h>
> >  
> >  /* --------------------------------------------------------------------------
> >   * UVC constants
> > @@ -41,6 +42,9 @@
> >  #define UVC_EXT_GPIO_UNIT		0x7ffe
> >  #define UVC_EXT_GPIO_UNIT_ID		0x100
> >  
> > +#define UVC_FWNODE_UNIT			0x7ffd
> > +#define UVC_FWNODE_UNIT_ID		0x101
> > +
> >  /* ------------------------------------------------------------------------
> >   * Driver specific constants.
> >   */
> > @@ -242,6 +246,12 @@ struct uvc_entity {
> >  			int irq;
> >  			bool initialized;
> >  		} gpio;
> > +
> > +		struct {
> > +			u8  bControlSize;
> > +			u8  *bmControls;
> > +			struct v4l2_fwnode_device_properties props;
> > +		} fwnode;
> >  	};
> >  
> >  	u8 bNrInPins;
> > @@ -617,6 +627,7 @@ struct uvc_device {
> >  	} async_ctrl;
> >  
> >  	struct uvc_entity *gpio_unit;
> > +	struct uvc_entity *fwnode_unit;
> >  };
> >  
> >  enum uvc_handle_state {
> > @@ -835,4 +846,8 @@ size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf,
> >  int uvc_gpio_parse(struct uvc_device *dev);
> >  int uvc_gpio_init_irq(struct uvc_device *dev);
> >  void uvc_gpio_deinit(struct uvc_device *dev);
> > +
> > +/* fwnode */
> > +int uvc_fwnode_parse(struct uvc_device *dev);
> > +
> >  #endif
> > diff --git a/include/linux/usb/uvc.h b/include/linux/usb/uvc.h
> > index bce95153e5a65613a710d7316fc17cf5462b5bce..d818839b0442988d94ab44935e1ce855b0adf4a1 100644
> > --- a/include/linux/usb/uvc.h
> > +++ b/include/linux/usb/uvc.h
> > @@ -29,6 +29,9 @@
> >  #define UVC_GUID_EXT_GPIO_CONTROLLER \
> >  	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
> >  	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x03}
> > +#define UVC_GUID_FWNODE \
> > +	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
> > +	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x04}
> >  
> >  #define UVC_GUID_FORMAT_MJPEG \
> >  	{ 'M',  'J',  'P',  'G', 0x00, 0x00, 0x10, 0x00, \
> > 

-- 
Regards,

Laurent Pinchart