[PATCH v15 11/16] media: uapi: Add audio rate controls support

[Shengjiu Wang]

Add V4L2_CID_M2M_AUDIO_SOURCE_RATE and V4L2_CID_M2M_AUDIO_DEST_RATE
new IDs for rate control.

Add V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET and
V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET for clock drift.

Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
---
 .../media/v4l/ext-ctrls-audio-m2m.rst         | 38 +++++++++++++++++++
 drivers/media/v4l2-core/v4l2-ctrls-defs.c     |  6 +++
 include/uapi/linux/v4l2-controls.h            |  5 +++
 3 files changed, 49 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
index 82d2ecedbfee..b137b7c442e6 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
@@ -19,3 +19,41 @@ Audio M2M Control IDs
     The Audio M2M class descriptor. Calling
     :ref:`VIDIOC_QUERYCTRL` for this control will
     return a description of this control class.
+
+.. _v4l2-audio-asrc:
+
+``V4L2_CID_M2M_AUDIO_SOURCE_RATE (integer menu)``
+    This control specifies the audio source sample rate, unit is Hz
+
+``V4L2_CID_M2M_AUDIO_DEST_RATE (integer menu)``
+    This control specifies the audio destination sample rate, unit is Hz
+
+``V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET (fixed point)``
+    This control specifies the offset from the audio source sample rate,
+    unit is Hz.
+
+    The offset compensates for any clock drift. The actual source audio
+    sample rate is the ideal source audio sample rate from
+    ``V4L2_CID_M2M_AUDIO_SOURCE_RATE`` plus this fixed point offset.
+
+    The audio source clock may have some drift. Reducing or increasing the
+    audio sample rate dynamically to ensure that Sample Rate Converter is
+    working on the real sample rate, this feature is for the Asynchronous
+    Sample Rate Converter module.
+    So, userspace would be expected to be monitoring such drift
+    and increasing/decreasing the sample frequency as needed by this control.
+
+``V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET (fixed point)``
+    This control specifies the offset from the audio destination sample rate,
+    unit is Hz.
+
+    The offset compensates for any clock drift. The actual destination audio
+    sample rate is the ideal source audio sample rate from
+    ``V4L2_CID_M2M_AUDIO_DEST_RATE`` plus this fixed point offset.
+
+    The audio destination clock may have some drift. Reducing or increasing
+    the audio sample rate dynamically to ensure that sample rate converter
+    is working on the real sample rate, this feature is for the Asynchronous
+    Sample Rate Converter module.
+    So, userspace would be expected to be monitoring such drift
+    and increasing/decreasing the sample frequency as needed by this control.
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
index 2a85ea3dc92f..91e1f5348c23 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
@@ -1245,6 +1245,8 @@ const char *v4l2_ctrl_get_name(u32 id)
 
 	/* Audio M2M controls */
 	case V4L2_CID_M2M_AUDIO_CLASS:  return "Audio M2M Controls";
+	case V4L2_CID_M2M_AUDIO_SOURCE_RATE:	return "Audio Source Sample Rate";
+	case V4L2_CID_M2M_AUDIO_DEST_RATE:	return "Audio Destination Sample Rate";
 	default:
 		return NULL;
 	}
@@ -1606,6 +1608,10 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
 	case V4L2_CID_COLORIMETRY_HDR10_MASTERING_DISPLAY:
 		*type = V4L2_CTRL_TYPE_HDR10_MASTERING_DISPLAY;
 		break;
+	case V4L2_CID_M2M_AUDIO_SOURCE_RATE:
+	case V4L2_CID_M2M_AUDIO_DEST_RATE:
+		*type = V4L2_CTRL_TYPE_INTEGER_MENU;
+		break;
 	default:
 		*type = V4L2_CTRL_TYPE_INTEGER;
 		break;
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index a8b4b830c757..30129ccdc282 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -3495,6 +3495,11 @@ struct v4l2_ctrl_av1_film_grain {
 #define V4L2_CID_M2M_AUDIO_CLASS_BASE  (V4L2_CTRL_CLASS_M2M_AUDIO | 0x900)
 #define V4L2_CID_M2M_AUDIO_CLASS       (V4L2_CTRL_CLASS_M2M_AUDIO | 1)
 
+#define V4L2_CID_M2M_AUDIO_SOURCE_RATE	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 0)
+#define V4L2_CID_M2M_AUDIO_DEST_RATE	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 1)
+#define V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 2)
+#define V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 3)
+
 /* MPEG-compression definitions kept for backwards compatibility */
 #ifndef __KERNEL__
 #define V4L2_CTRL_CLASS_MPEG            V4L2_CTRL_CLASS_CODEC
-- 
2.34.1