[libcamera-devel] [PATCH 4/6] libcamera: v4l2_device: Add single/multiplane formats

[Jacopo Mondi]

Add a class hierarchy internal to V4L2Device to handle set/get format
operations in the single/multi plane use case.

Provide stubs only for  get/setFormat methods at the moment.
---
 src/libcamera/include/v4l2_device.h | 34 +++++++++++++++++
 src/libcamera/v4l2_device.cpp       | 59 +++++++++++++++++++++++++++++
 2 files changed, 93 insertions(+)

diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h
index 0101a4b..81992dc 100644
--- a/src/libcamera/include/v4l2_device.h
+++ b/src/libcamera/include/v4l2_device.h
@@ -7,6 +7,7 @@
 #ifndef __LIBCAMERA_V4L2_DEVICE_H__
 #define __LIBCAMERA_V4L2_DEVICE_H__
 
+#include <memory>
 #include <string>
 
 #include <linux/videodev2.h>
@@ -54,11 +55,44 @@ public:
 	const char *busName() const { return caps_.bus_info(); }
 
 	int setControl(unsigned int control, int value);
+	int getFormat();
+	int setFormat();
 
 private:
+	class V4L2Format
+	{
+	public:
+		virtual ~V4L2Format() { }
+		virtual int setFormat() = 0;
+		virtual int getFormat() = 0;
+
+	protected:
+		V4L2Format() { }
+		V4L2Format(V4L2Format &) = delete;
+	};
+
+	class V4L2FormatSPlane : public V4L2Format
+	{
+	public:
+		V4L2FormatSPlane() { }
+		~V4L2FormatSPlane() { }
+		int setFormat();
+		int getFormat();
+	};
+
+	class V4L2FormatMPlane : public V4L2Format
+	{
+	public:
+		V4L2FormatMPlane() { }
+		~V4L2FormatMPlane() { }
+		int setFormat();
+		int getFormat();
+	};
+
 	std::string devnode_;
 	int fd_;
 	V4L2Capability caps_;
+	std::unique_ptr<V4L2Format> format_;
 };
 
 } /* namespace libcamera */
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 7cd89d7..126f6f2 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -5,6 +5,8 @@
  * v4l2_device.cpp - V4L2 Device
  */
 
+#include <memory>
+
 #include <fcntl.h>
 #include <string.h>
 #include <sys/ioctl.h>
@@ -13,6 +15,7 @@
 
 #include "log.h"
 #include "media_object.h"
+#include "utils.h"
 #include "v4l2_device.h"
 
 /**
@@ -182,6 +185,12 @@ int V4L2Device::open()
 		return -EINVAL;
 	}
 
+	/* Create single/multi plane format handler. */
+	if (caps_.isSinglePlane())
+		format_ = utils::make_unique<V4L2FormatSPlane>();
+	else
+		format_ = utils::make_unique<V4L2FormatMPlane>();
+
 	return 0;
 }
 
@@ -262,4 +271,54 @@ int V4L2Device::setControl(unsigned int control, int value)
 	return v4l2_ctrl.value;
 }
 
+/**
+ * \brief Retrieve the image format set on the V4L2 device
+ *
+ * TODO: define how the image format is encoded
+ * FIXME: this function is a stub at the moment
+ *
+ * \return 0 for success, a negative error code otherwise
+ */
+int V4L2Device::getFormat()
+{
+	return format_->getFormat();
+}
+
+/**
+ * \brief Program an image format on the V4L2 device
+ *
+ * TODO: define how the image format is encoded
+ * FIXME: this function is a stub at the moment
+ *
+ * \return 0 for success, a negative error code otherwise
+ */
+int V4L2Device::setFormat()
+{
+	return format_->setFormat();
+}
+
+/* FIXME: this function is a stub at the moment. */
+int V4L2Device::V4L2FormatSPlane::getFormat()
+{
+	return 0;
+}
+
+/* FIXME: this function is a stub at the moment. */
+int V4L2Device::V4L2FormatSPlane::setFormat()
+{
+	return 0;
+}
+
+/* FIXME: this function is a stub at the moment. */
+int V4L2Device::V4L2FormatMPlane::getFormat()
+{
+	return 0;
+}
+
+/* FIXME: this function is a stub at the moment. */
+int V4L2Device::V4L2FormatMPlane::setFormat()
+{
+	return 0;
+}
+
 } /* namespace libcamera */
-- 
2.20.1