libcamera: pipeline: Raspberry Pi pipeline handler

Initial implementation of the Raspberry Pi (BCM2835) ISP pipeline
handler.

All code is licensed under the BSD-2-Clause terms.
Copyright (c) 2019-2020 Raspberry Pi Trading Ltd.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 236 insertions, 0 deletions

diff --git a/src/libcamera/pipeline/raspberrypi/staggered_ctrl.h b/src/libcamera/pipeline/raspberrypi/staggered_ctrl.h
new file mode 100644
index 00000000..0403c087
--- /dev/null
+++ b/src/libcamera/pipeline/raspberrypi/staggered_ctrl.h
@@ -0,0 +1,236 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2020, Raspberry Pi (Trading) Ltd.
+ *
+ * staggered_ctrl.h - Helper for writing staggered ctrls to a V4L2 device.
+ */
+#pragma once
+
+#include <algorithm>
+#include <initializer_list>
+#include <mutex>
+#include <unordered_map>
+
+#include <libcamera/controls.h>
+#include "log.h"
+#include "utils.h"
+#include "v4l2_videodevice.h"
+
+/* For logging... */
+using libcamera::LogCategory;
+using libcamera::LogDebug;
+using libcamera::LogInfo;
+using libcamera::utils::hex;
+
+LOG_DEFINE_CATEGORY(RPI_S_W);
+
+namespace RPi {
+
+class StaggeredCtrl
+{
+public:
+	StaggeredCtrl()
+		: init_(false), setCount_(0), getCount_(0), maxDelay_(0)
+	{
+	}
+
+	~StaggeredCtrl()
+	{
+	}
+
+	operator bool() const
+	{
+		return init_;
+	}
+
+	void init(libcamera::V4L2VideoDevice *dev,
+		  std::initializer_list<std::pair<const uint32_t, uint8_t>> delayList)
+	{
+		std::lock_guard<std::mutex> lock(lock_);
+
+		dev_ = dev;
+		delay_ = delayList;
+		ctrl_.clear();
+
+		/* Find the largest delay across all controls. */
+		maxDelay_ = 0;
+		for (auto const &p : delay_) {
+			LOG(RPI_S_W, Info) << "Init ctrl "
+					   << hex(p.first) << " with delay "
+					   << static_cast<int>(p.second);
+			maxDelay_ = std::max(maxDelay_, p.second);
+		}
+
+		init_ = true;
+	}
+
+	void reset()
+	{
+		std::lock_guard<std::mutex> lock(lock_);
+
+		int lastSetCount = std::max<int>(0, setCount_ - 1);
+		std::unordered_map<uint32_t, int32_t> lastVal;
+
+		/* Reset the counters. */
+		setCount_ = getCount_ = 0;
+
+		/* Look for the last set values. */
+		for (auto const &c : ctrl_)
+			lastVal[c.first] = c.second[lastSetCount].value;
+
+		/* Apply the last set values as the next to be applied. */
+		ctrl_.clear();
+		for (auto &c : lastVal)
+			ctrl_[c.first][setCount_] = CtrlInfo(c.second);
+	}
+
+	bool set(uint32_t ctrl, int32_t value)
+	{
+		std::lock_guard<std::mutex> lock(lock_);
+
+		/* Can we find this ctrl as one that is registered? */
+		if (delay_.find(ctrl) == delay_.end())
+			return false;
+
+		ctrl_[ctrl][setCount_].value = value;
+		ctrl_[ctrl][setCount_].updated = true;
+
+		return true;
+	}
+
+	bool set(std::initializer_list<std::pair<const uint32_t, int32_t>> ctrlList)
+	{
+		std::lock_guard<std::mutex> lock(lock_);
+
+		for (auto const &p : ctrlList) {
+			/* Can we find this ctrl? */
+			if (delay_.find(p.first) == delay_.end())
+				return false;
+
+			ctrl_[p.first][setCount_] = CtrlInfo(p.second);
+		}
+
+		return true;
+	}
+
+	bool set(libcamera::ControlList &controls)
+	{
+		std::lock_guard<std::mutex> lock(lock_);
+
+		for (auto const &p : controls) {
+			/* Can we find this ctrl? */
+			if (delay_.find(p.first) == delay_.end())
+				return false;
+
+			ctrl_[p.first][setCount_] = CtrlInfo(p.second.get<int32_t>());
+			LOG(RPI_S_W, Debug) << "Setting ctrl "
+					    << hex(p.first) << " to "
+					    << ctrl_[p.first][setCount_].value
+					    << " at index "
+					    << setCount_;
+		}
+
+		return true;
+	}
+
+	int write()
+	{
+		std::lock_guard<std::mutex> lock(lock_);
+		libcamera::ControlList controls(dev_->controls());
+
+		for (auto &p : ctrl_) {
+			int delayDiff = maxDelay_ - delay_[p.first];
+			int index = std::max<int>(0, setCount_ - delayDiff);
+
+			if (p.second[index].updated) {
+				/* We need to write this value out. */
+				controls.set(p.first, p.second[index].value);
+				p.second[index].updated = false;
+				LOG(RPI_S_W, Debug) << "Writing ctrl "
+						    << hex(p.first) << " to "
+						    << p.second[index].value
+						    << " at index "
+						    << index;
+			}
+		}
+
+		nextFrame();
+		return dev_->setControls(&controls);
+	}
+
+	void get(std::unordered_map<uint32_t, int32_t> &ctrl, uint8_t offset = 0)
+	{
+		std::lock_guard<std::mutex> lock(lock_);
+
+		/* Account for the offset to reset the getCounter. */
+		getCount_ += offset + 1;
+
+		ctrl.clear();
+		for (auto &p : ctrl_) {
+			int index = std::max<int>(0, getCount_ - maxDelay_);
+			ctrl[p.first] = p.second[index].value;
+			LOG(RPI_S_W, Debug) << "Getting ctrl "
+					    << hex(p.first) << " to "
+					    << p.second[index].value
+					    << " at index "
+					    << index;
+		}
+	}
+
+private:
+	void nextFrame()
+	{
+		/* Advance the control history to the next frame */
+		int prevCount = setCount_;
+		setCount_++;
+
+		LOG(RPI_S_W, Debug) << "Next frame, set index is " << setCount_;
+
+		for (auto &p : ctrl_) {
+			p.second[setCount_].value = p.second[prevCount].value;
+			p.second[setCount_].updated = false;
+		}
+	}
+
+	/* listSize must be a power of 2. */
+	static constexpr int listSize = (1 << 4);
+	struct CtrlInfo {
+		CtrlInfo()
+			: value(0), updated(false)
+		{
+		}
+
+		CtrlInfo(int32_t value_)
+			: value(value_), updated(true)
+		{
+		}
+
+		int32_t value;
+		bool updated;
+	};
+
+	class CircularArray : public std::array<CtrlInfo, listSize>
+	{
+	public:
+		CtrlInfo &operator[](int index)
+		{
+			return std::array<CtrlInfo, listSize>::operator[](index & (listSize - 1));
+		}
+
+		const CtrlInfo &operator[](int index) const
+		{
+			return std::array<CtrlInfo, listSize>::operator[](index & (listSize - 1));
+		}
+	};
+
+	bool init_;
+	uint32_t setCount_;
+	uint32_t getCount_;
+	uint8_t maxDelay_;
+	libcamera::V4L2VideoDevice *dev_;
+	std::unordered_map<uint32_t, uint8_t> delay_;
+	std::unordered_map<uint32_t, CircularArray> ctrl_;
+	std::mutex lock_;
+};
+
+} /* namespace RPi */