[PATCH v4 4/5] libcamera: converter: Add DW100 converter class

[Umang Jain]

DW100 Dewarp engine is present on i.MX8MP SoC. This patch
provides a converter class (inherited from V4L2M2MConverter).

The DW100 converter will be used for scaling capabilites hence, has
a helper to set scaler crop rectangles. Plumbing in the RkISP1
pipeline-handler is done in the subsequent patch.

The ConverterDW100 class can be extended later (as additional
development) to support the dewarping by setting a dewarp vertex map.

Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
 .../internal/converter/converter_dw100.h      | 26 ++++++++
 .../libcamera/internal/converter/meson.build  |  1 +
 src/libcamera/converter/converter_dw100.cpp   | 64 +++++++++++++++++++
 src/libcamera/converter/meson.build           |  1 +
 4 files changed, 92 insertions(+)
 create mode 100644 include/libcamera/internal/converter/converter_dw100.h
 create mode 100644 src/libcamera/converter/converter_dw100.cpp

diff --git a/include/libcamera/internal/converter/converter_dw100.h b/include/libcamera/internal/converter/converter_dw100.h
new file mode 100644
index 00000000..dbd39e08
--- /dev/null
+++ b/include/libcamera/internal/converter/converter_dw100.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024, Ideas On Board Oy
+ *
+ * i.MX8MP Dewarp Engine integration
+ */
+
+#pragma once
+
+#include "libcamera/internal/converter/converter_v4l2_m2m.h"
+
+namespace libcamera {
+
+class MediaDevice;
+class Rectangle;
+class Stream;
+
+class ConverterDW100 : public V4L2M2MConverter
+{
+public:
+	ConverterDW100(std::shared_ptr<MediaDevice> media);
+
+	int setScalerCrop(const Stream *stream, Rectangle *rect);
+};
+
+} /* namespace libcamera */
diff --git a/include/libcamera/internal/converter/meson.build b/include/libcamera/internal/converter/meson.build
index 891e79e7..85007a4b 100644
--- a/include/libcamera/internal/converter/meson.build
+++ b/include/libcamera/internal/converter/meson.build
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: CC0-1.0
 
 libcamera_internal_headers += files([
+    'converter_dw100.h',
     'converter_v4l2_m2m.h',
 ])
diff --git a/src/libcamera/converter/converter_dw100.cpp b/src/libcamera/converter/converter_dw100.cpp
new file mode 100644
index 00000000..78802615
--- /dev/null
+++ b/src/libcamera/converter/converter_dw100.cpp
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024, Ideas On Board Oy
+ *
+ * i.MX8MP Dewarp Engine integration
+ */
+
+#include "libcamera/internal/converter/converter_dw100.h"
+
+#include <libcamera/base/log.h>
+
+#include <libcamera/geometry.h>
+
+#include "libcamera/internal/media_device.h"
+#include "libcamera/internal/v4l2_videodevice.h"
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(Converter)
+
+/**
+ * \class libcamera::ConverterDW100
+ * \brief The i.MX8MP dewarp converter implements the converter interface based
+ * on V4L2 M2M device.
+*/
+
+/**
+ * \fn ConverterDW100::ConverterDW100
+ * \brief Construct a ConverterDW100 instance
+ * \param[in] media The media device implementing the converter
+ */
+ConverterDW100::ConverterDW100(std::shared_ptr<MediaDevice> media)
+	: V4L2M2MConverter(media.get(), Feature::Crop)
+{
+}
+
+/**
+ * \brief Set the scaler crop rectangle \a rect on \a stream
+ * \param[in] stream Pointer to output stream
+ * \param[inout] rect The selection rectangle to be applied
+ *
+ * \return 0 on success or a negative error code otherwise
+ */
+int ConverterDW100::setScalerCrop(const Stream *stream, Rectangle *rect)
+{
+	Rectangle apply = *rect;
+	int ret;
+
+	ret = setCrop(stream, &apply);
+	if (ret < 0)
+		LOG(Converter, Error) << "Failed to set scaler crop "
+				      << apply.toString() << " on dewarper "
+				      << strerror(-ret);
+
+	if (*rect != apply) {
+		/* \todo This case needs proper after handling. */
+		LOG(Converter, Warning) << "Applied rectangle " << apply.toString()
+					<< " differs from requested " << rect->toString();
+	}
+
+	return ret;
+}
+
+} /* namespace libcamera */
diff --git a/src/libcamera/converter/meson.build b/src/libcamera/converter/meson.build
index 2aa72fe4..175581b8 100644
--- a/src/libcamera/converter/meson.build
+++ b/src/libcamera/converter/meson.build
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: CC0-1.0
 
 libcamera_sources += files([
+        'converter_dw100.cpp',
         'converter_v4l2_m2m.cpp'
 ])
-- 
2.44.0