pipeline: ipa: raspberrypi: Refactor and move the Raspberry Pi code

Split the Raspberry Pi pipeline handler and IPA source code into common
and VC4/BCM2835 specific file structures.

For the pipeline handler, the common code files now live in
src/libcamera/pipeline/rpi/common/
and the VC4-specific files in src/libcamera/pipeline/rpi/vc4/.

For the IPA, the common code files now live in
src/ipa/rpi/{cam_helper,controller}/
and the vc4 specific files in src/ipa/rpi/vc4/. With this change, the
camera tuning files are now installed under share/libcamera/ipa/rpi/vc4/.

To build the pipeline and IPA, the meson configuration options have now
changed from "raspberrypi" to "rpi/vc4":

meson setup build -Dipas=rpi/vc4 -Dpipelines=rpi/vc4

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 132 insertions, 0 deletions

diff --git a/src/ipa/rpi/cam_helper/cam_helper.h b/src/ipa/rpi/cam_helper/cam_helper.h
new file mode 100644
index 00000000..58a4b202
--- /dev/null
+++ b/src/ipa/rpi/cam_helper/cam_helper.h
@@ -0,0 +1,132 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * cam_helper.h - helper class providing camera information
+ */
+#pragma once
+
+#include <memory>
+#include <string>
+#include <utility>
+
+#include <libcamera/base/span.h>
+#include <libcamera/base/utils.h>
+
+#include "controller/camera_mode.h"
+#include "controller/controller.h"
+#include "controller/metadata.h"
+#include "md_parser.h"
+
+#include "libcamera/internal/v4l2_videodevice.h"
+
+namespace RPiController {
+
+/*
+ * The CamHelper class provides a number of facilities that anyone trying
+ * to drive a camera will need to know, but which are not provided by the
+ * standard driver framework. Specifically, it provides:
+ *
+ * A "CameraMode" structure to describe extra information about the chosen
+ * mode of the driver. For example, how it is cropped from the full sensor
+ * area, how it is scaled, whether pixels are averaged compared to the full
+ * resolution.
+ *
+ * The ability to convert between number of lines of exposure and actual
+ * exposure time, and to convert between the sensor's gain codes and actual
+ * gains.
+ *
+ * A function to return the number of frames of delay between updating exposure,
+ * analogue gain and vblanking, and for the changes to take effect. For many
+ * sensors these take the values 2, 1 and 2 respectively, but sensors that are
+ * different will need to over-ride the default function provided.
+ *
+ * A function to query if the sensor outputs embedded data that can be parsed.
+ *
+ * A function to return the sensitivity of a given camera mode.
+ *
+ * A parser to parse the embedded data buffers provided by some sensors (for
+ * example, the imx219 does; the ov5647 doesn't). This allows us to know for
+ * sure the exposure and gain of the frame we're looking at. CamHelper
+ * provides functions for converting analogue gains to and from the sensor's
+ * native gain codes.
+ *
+ * Finally, a set of functions that determine how to handle the vagaries of
+ * different camera modules on start-up or when switching modes. Some
+ * modules may produce one or more frames that are not yet correctly exposed,
+ * or where the metadata may be suspect. We have the following functions:
+ * HideFramesStartup(): Tell the pipeline handler not to return this many
+ *     frames at start-up. This can also be used to hide initial frames
+ *     while the AGC and other algorithms are sorting themselves out.
+ * HideFramesModeSwitch(): Tell the pipeline handler not to return this
+ *     many frames after a mode switch (other than start-up). Some sensors
+ *     may produce innvalid frames after a mode switch; others may not.
+ * MistrustFramesStartup(): At start-up a sensor may return frames for
+ *    which we should not run any control algorithms (for example, metadata
+ *    may be invalid).
+ * MistrustFramesModeSwitch(): The number of frames, after a mode switch
+ *    (other than start-up), for which control algorithms should not run
+ *    (for example, metadata may be unreliable).
+ */
+
+class CamHelper
+{
+public:
+	static CamHelper *create(std::string const &camName);
+	CamHelper(std::unique_ptr<MdParser> parser, unsigned int frameIntegrationDiff);
+	virtual ~CamHelper();
+	void setCameraMode(const CameraMode &mode);
+	virtual void prepare(libcamera::Span<const uint8_t> buffer,
+			     Metadata &metadata);
+	virtual void process(StatisticsPtr &stats, Metadata &metadata);
+	virtual uint32_t exposureLines(const libcamera::utils::Duration exposure,
+				       const libcamera::utils::Duration lineLength) const;
+	virtual libcamera::utils::Duration exposure(uint32_t exposureLines,
+						    const libcamera::utils::Duration lineLength) const;
+	virtual std::pair<uint32_t, uint32_t> getBlanking(libcamera::utils::Duration &exposure,
+							  libcamera::utils::Duration minFrameDuration,
+							  libcamera::utils::Duration maxFrameDuration) const;
+	libcamera::utils::Duration hblankToLineLength(uint32_t hblank) const;
+	uint32_t lineLengthToHblank(const libcamera::utils::Duration &duration) const;
+	libcamera::utils::Duration lineLengthPckToDuration(uint32_t lineLengthPck) const;
+	virtual uint32_t gainCode(double gain) const = 0;
+	virtual double gain(uint32_t gainCode) const = 0;
+	virtual void getDelays(int &exposureDelay, int &gainDelay,
+			       int &vblankDelay, int &hblankDelay) const;
+	virtual bool sensorEmbeddedDataPresent() const;
+	virtual double getModeSensitivity(const CameraMode &mode) const;
+	virtual unsigned int hideFramesStartup() const;
+	virtual unsigned int hideFramesModeSwitch() const;
+	virtual unsigned int mistrustFramesStartup() const;
+	virtual unsigned int mistrustFramesModeSwitch() const;
+
+protected:
+	void parseEmbeddedData(libcamera::Span<const uint8_t> buffer,
+			       Metadata &metadata);
+	virtual void populateMetadata(const MdParser::RegisterMap &registers,
+				      Metadata &metadata) const;
+
+	std::unique_ptr<MdParser> parser_;
+	CameraMode mode_;
+
+private:
+	/*
+	 * Smallest difference between the frame length and integration time,
+	 * in units of lines.
+	 */
+	unsigned int frameIntegrationDiff_;
+};
+
+/*
+ * This is for registering camera helpers with the system, so that the
+ * CamHelper::Create function picks them up automatically.
+ */
+
+typedef CamHelper *(*CamHelperCreateFunc)();
+struct RegisterCamHelper
+{
+	RegisterCamHelper(char const *camName,
+			  CamHelperCreateFunc createFunc);
+};
+
+} /* namespace RPi */