[libcamera-devel] [PATCH 08/11] licamera: v4l2_device: Support reading U8 array controls

[Jacopo Mondi]

Add support to retrieve the value of array controls of type
V4L2_CTRL_TYPE_U8.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/libcamera/v4l2_device.cpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 950e6286b84d..464df6a1fe18 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -185,6 +185,22 @@ int V4L2Device::getControls(ControlList *ctrls)
 			return -EINVAL;
 		}
 
+		const struct v4l2_query_ext_ctrl &info = ctrlsInfo_[id];
+		if (info.flags & V4L2_CTRL_FLAG_HAS_PAYLOAD) {
+			if (info.type != V4L2_CTRL_TYPE_U8) {
+				/*
+				 * \todo Fail loudly to notify support for
+				 * other array control types is not implemented.
+				 */
+				LOG(V4L2, Error) << "Unsupported type";
+				return -EINVAL;
+			}
+
+			size_t sizeBytes = info.elems * info.elem_size;
+			v4l2Ctrls[i].p_u8 = new uint8_t[sizeBytes];
+			v4l2Ctrls[i].size = sizeBytes;
+		}
+
 		v4l2Ctrls[i].id = id;
 		i++;
 	}
@@ -214,6 +230,16 @@ int V4L2Device::getControls(ControlList *ctrls)
 
 	updateControls(ctrls, v4l2Ctrls, count);
 
+	/* Release memory reserved for array controls. */
+	for (unsigned int i = 0; i < count; i++) {
+		unsigned int id = v4l2Ctrls[i].id;
+		const struct v4l2_query_ext_ctrl &info = ctrlsInfo_[id];
+
+		/* \todo Adjust to support more array control types. */
+		if (info.flags & V4L2_CTRL_FLAG_HAS_PAYLOAD)
+			delete[] v4l2Ctrls[i].p_u8;
+	}
+
 	return ret;
 }
 
-- 
2.25.0