[RFC/WIP v2 2/6] v4l: Add HEIF control class and control IDs

[Stanimir Varbanov <stanimir.varbanov@linaro.org>]

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
---
 .../media/v4l/ext-ctrls-heif.rst              | 47 +++++++++++++++++++
 drivers/media/v4l2-core/v4l2-ctrls-defs.c     | 10 ++++
 include/uapi/linux/v4l2-controls.h            |  9 ++++
 3 files changed, 66 insertions(+)
 create mode 100644 Documentation/userspace-api/media/v4l/ext-ctrls-heif.rst

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-heif.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-heif.rst
new file mode 100644
index 000000000000..e2a7f45a3821
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-heif.rst
@@ -0,0 +1,47 @@
+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+
+.. _heif-controls:
+
+**********************
+HEIF Control Reference
+**********************
+
+The HEIF (High Efficiency Image File Format) class includes controls for
+common features of HEIF encoders.
+
+.. _heif-control-id:
+
+HEIF Control IDs
+================
+
+``V4L2_CID_HEIF_CLASS (class)``
+    The HEIF class descriptor. Calling :ref:`VIDIOC_QUERYCTRL` for this
+    control will return a description of this control class.
+
+.. _heif-hevc-grid-controls:
+
+The following controls are used to describe the parameters for derived
+image item of type 'grid'. The encoded input image will be divided on
+NxM grids with grid_width by grid_height pixels. The input width and
+height will satisfy the following equation:
+
+grid_width  * grid_columns >= input_image_width
+grid_height * grid_rows    >= input_image_height
+
+All grids shall have the same grid_width and grid_height.
+
+``V4L2_CID_HEIF_HEVC_GRID_WIDTH (integer)``
+    Specify the grid width in pixels.
+
+``V4L2_CID_HEIF_HEVC_GRID_HEIGHT (integer)``
+    Specify the grid height in pixels.
+
+``V4L2_CID_HEIF_HEVC_GRID_ROWS (integer)``
+    Specify the number of grid rows. If client sets grid rows and columns to 1,
+    no image division will be applied.
+
+``V4L2_CID_HEIF_HEVC_GRID_COLUMNS (integer)``
+    Specify the number of grid columns. If client sets grid rows and columns to 1,
+    no image division will be applied.
+
+For more details about HEIF specification, refer to ISO/IEC 23008-12:2017.
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
index 54ca4e6b820b..31d05fac9dac 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
@@ -1186,6 +1186,15 @@ const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_COLORIMETRY_CLASS:	return "Colorimetry Controls";
 	case V4L2_CID_COLORIMETRY_HDR10_CLL_INFO:		return "HDR10 Content Light Info";
 	case V4L2_CID_COLORIMETRY_HDR10_MASTERING_DISPLAY:	return "HDR10 Mastering Display";
+
+	/* HEIF controls */
+	/* Keep the order of the 'case's the same as in v4l2-controls.h! */
+	case V4L2_CID_HEIF_CLASS:		return "HEIF Controls";
+	case V4L2_CID_HEIF_HEVC_GRID_WIDTH:	return "HEIF HEVC Grid Width";
+	case V4L2_CID_HEIF_HEVC_GRID_HEIGHT:	return "HEIF HEVC Grid Height";
+	case V4L2_CID_HEIF_HEVC_GRID_ROWS:	return "HEIF HEVC Grid Rows";
+	case V4L2_CID_HEIF_HEVC_GRID_COLUMNS:	return "HEIF HEVC Grid Columns";
+
 	default:
 		return NULL;
 	}
@@ -1391,6 +1400,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
 	case V4L2_CID_DETECT_CLASS:
 	case V4L2_CID_CODEC_STATELESS_CLASS:
 	case V4L2_CID_COLORIMETRY_CLASS:
+	case V4L2_CID_HEIF_CLASS:
 		*type = V4L2_CTRL_TYPE_CTRL_CLASS;
 		/* You can neither read nor write these */
 		*flags |= V4L2_CTRL_FLAG_READ_ONLY | V4L2_CTRL_FLAG_WRITE_ONLY;
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index c8e0f84d204d..45a3b399272c 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -68,6 +68,7 @@
 #define V4L2_CTRL_CLASS_DETECT		0x00a30000	/* Detection controls */
 #define V4L2_CTRL_CLASS_CODEC_STATELESS 0x00a40000	/* Stateless codecs controls */
 #define V4L2_CTRL_CLASS_COLORIMETRY	0x00a50000	/* Colorimetry controls */
+#define V4L2_CTRL_CLASS_HEIF		0x00a60000	/* HEIF controls */
 
 /* User-class control IDs */
 
@@ -2302,6 +2303,14 @@ struct v4l2_ctrl_vp9_compressed_hdr {
 	struct v4l2_vp9_mv_probs mv;
 };
 
+#define V4L2_CID_HEIF_CLASS_BASE	(V4L2_CTRL_CLASS_HEIF | 0x900)
+#define V4L2_CID_HEIF_CLASS		(V4L2_CTRL_CLASS_HEIF | 1)
+
+#define V4L2_CID_HEIF_HEVC_GRID_WIDTH	(V4L2_CID_HEIF_CLASS_BASE + 0)
+#define V4L2_CID_HEIF_HEVC_GRID_HEIGHT	(V4L2_CID_HEIF_CLASS_BASE + 1)
+#define V4L2_CID_HEIF_HEVC_GRID_ROWS	(V4L2_CID_HEIF_CLASS_BASE + 2)
+#define V4L2_CID_HEIF_HEVC_GRID_COLUMNS	(V4L2_CID_HEIF_CLASS_BASE + 3)
+
 /* MPEG-compression definitions kept for backwards compatibility */
 #ifndef __KERNEL__
 #define V4L2_CTRL_CLASS_MPEG            V4L2_CTRL_CLASS_CODEC
-- 
2.25.1