1 files changed, 87 insertions, 0 deletions
diff --git a/src/libcamera/pipeline/rpi/common/delayed_controls.h b/src/libcamera/pipeline/rpi/common/delayed_controls.h
new file mode 100644
index 00000000..61f755f0
--- /dev/null
+++ b/src/libcamera/pipeline/rpi/common/delayed_controls.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Raspberry Pi Ltd
+ *
+ * delayed_controls.h - Helper to deal with controls that take effect with a delay
+ *
+ * Note: This has been forked from the libcamera core implementation.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <unordered_map>
+#include <utility>
+
+#include <libcamera/controls.h>
+
+namespace libcamera {
+
+class V4L2Device;
+
+namespace RPi {
+
+class DelayedControls
+{
+public:
+	struct ControlParams {
+		unsigned int delay;
+		bool priorityWrite;
+	};
+
+	DelayedControls(V4L2Device *device,
+			const std::unordered_map<uint32_t, ControlParams> &controlParams);
+
+	void reset(unsigned int cookie);
+
+	bool push(const ControlList &controls, unsigned int cookie);
+	std::pair<ControlList, unsigned int> get(uint32_t sequence);
+
+	void applyControls(uint32_t sequence);
+
+private:
+	class Info : public ControlValue
+	{
+	public:
+		Info()
+			: updated(false)
+		{
+		}
+
+		Info(const ControlValue &v, bool updated_ = true)
+			: ControlValue(v), updated(updated_)
+		{
+		}
+
+		bool updated;
+	};
+
+	static constexpr int listSize = 16;
+	template<typename T>
+	class RingBuffer : public std::array<T, listSize>
+	{
+	public:
+		T &operator[](unsigned int index)
+		{
+			return std::array<T, listSize>::operator[](index % listSize);
+		}
+
+		const T &operator[](unsigned int index) const
+		{
+			return std::array<T, listSize>::operator[](index % listSize);
+		}
+	};
+
+	V4L2Device *device_;
+	std::unordered_map<const ControlId *, ControlParams> controlParams_;
+	unsigned int maxDelay_;
+
+	uint32_t queueCount_;
+	uint32_t writeCount_;
+	std::unordered_map<const ControlId *, RingBuffer<Info>> values_;
+	RingBuffer<unsigned int> cookies_;
+};
+
+} /* namespace RPi */
+
+} /* namespace libcamera */