[libcamera-devel] [PATCH v6 1/8] pipeline: raspberrypi: Fork DelayedControls
Naushir Patuck
naush at raspberrypi.com
Tue Nov 15 10:07:48 CET 2022
Fork the libcamera::DelayedControls implementation in the RPi:: namespace, with
the intention of updating the API for Raspberry Pi specific features.
Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
.../pipeline/raspberrypi/delayed_controls.cpp | 291 ++++++++++++++++++
.../pipeline/raspberrypi/delayed_controls.h | 84 +++++
.../pipeline/raspberrypi/meson.build | 1 +
3 files changed, 376 insertions(+)
create mode 100644 src/libcamera/pipeline/raspberrypi/delayed_controls.cpp
create mode 100644 src/libcamera/pipeline/raspberrypi/delayed_controls.h
diff --git a/src/libcamera/pipeline/raspberrypi/delayed_controls.cpp b/src/libcamera/pipeline/raspberrypi/delayed_controls.cpp
new file mode 100644
index 000000000000..867e3866cc46
--- /dev/null
+++ b/src/libcamera/pipeline/raspberrypi/delayed_controls.cpp
@@ -0,0 +1,291 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Raspberry Pi Ltd
+ *
+ * delayed_controls.cpp - Helper to deal with controls that take effect with a delay
+ *
+ * Note: This has been forked from the libcamera core implementation.
+ */
+
+#include "delayed_controls.h"
+
+#include <libcamera/base/log.h>
+
+#include <libcamera/controls.h>
+
+#include "libcamera/internal/v4l2_device.h"
+
+/**
+ * \file delayed_controls.h
+ * \brief Helper to deal with controls that take effect with a delay
+ */
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(RPiDelayedControls)
+
+namespace RPi {
+
+/**
+ * \class DelayedControls
+ * \brief Helper to deal with controls that take effect with a delay
+ *
+ * Some sensor controls take effect with a delay as the sensor needs time to
+ * adjust, for example exposure and analog gain. This is a helper class to deal
+ * with such controls and the intended users are pipeline handlers.
+ *
+ * The idea is to extend the concept of the buffer depth of a pipeline the
+ * application needs to maintain to also cover controls. Just as with buffer
+ * depth if the application keeps the number of requests queued above the
+ * control depth the controls are guaranteed to take effect for the correct
+ * request. The control depth is determined by the control with the greatest
+ * delay.
+ */
+
+/**
+ * \struct DelayedControls::ControlParams
+ * \brief Parameters associated with controls handled by the \a DelayedControls
+ * helper class
+ *
+ * \var ControlParams::delay
+ * \brief Frame delay from setting the control on a sensor device to when it is
+ * consumed during framing.
+ *
+ * \var ControlParams::priorityWrite
+ * \brief Flag to indicate that this control must be applied ahead of, and
+ * separately from the other controls.
+ *
+ * Typically set for the \a V4L2_CID_VBLANK control so that the device driver
+ * does not reject \a V4L2_CID_EXPOSURE control values that may be outside of
+ * the existing vertical blanking specified bounds, but are within the new
+ * blanking bounds.
+ */
+
+/**
+ * \brief Construct a DelayedControls instance
+ * \param[in] device The V4L2 device the controls have to be applied to
+ * \param[in] controlParams Map of the numerical V4L2 control ids to their
+ * associated control parameters.
+ *
+ * The control parameters comprise of delays (in frames) and a priority write
+ * flag. If this flag is set, the relevant control is written separately from,
+ * and ahead of the rest of the batched controls.
+ *
+ * Only controls specified in \a controlParams are handled. If it's desired to
+ * mix delayed controls and controls that take effect immediately the immediate
+ * controls must be listed in the \a controlParams map with a delay value of 0.
+ */
+DelayedControls::DelayedControls(V4L2Device *device,
+ const std::unordered_map<uint32_t, ControlParams> &controlParams)
+ : device_(device), maxDelay_(0)
+{
+ const ControlInfoMap &controls = device_->controls();
+
+ /*
+ * Create a map of control ids to delays for controls exposed by the
+ * device.
+ */
+ for (auto const ¶m : controlParams) {
+ auto it = controls.find(param.first);
+ if (it == controls.end()) {
+ LOG(RPiDelayedControls, Error)
+ << "Delay request for control id "
+ << utils::hex(param.first)
+ << " but control is not exposed by device "
+ << device_->deviceNode();
+ continue;
+ }
+
+ const ControlId *id = it->first;
+
+ controlParams_[id] = param.second;
+
+ LOG(RPiDelayedControls, Debug)
+ << "Set a delay of " << controlParams_[id].delay
+ << " and priority write flag " << controlParams_[id].priorityWrite
+ << " for " << id->name();
+
+ maxDelay_ = std::max(maxDelay_, controlParams_[id].delay);
+ }
+
+ reset();
+}
+
+/**
+ * \brief Reset state machine
+ *
+ * Resets the state machine to a starting position based on control values
+ * retrieved from the device.
+ */
+void DelayedControls::reset()
+{
+ queueCount_ = 1;
+ writeCount_ = 0;
+
+ /* Retrieve control as reported by the device. */
+ std::vector<uint32_t> ids;
+ for (auto const ¶m : controlParams_)
+ ids.push_back(param.first->id());
+
+ ControlList controls = device_->getControls(ids);
+
+ /* Seed the control queue with the controls reported by the device. */
+ values_.clear();
+ for (const auto &ctrl : controls) {
+ const ControlId *id = device_->controls().idmap().at(ctrl.first);
+ /*
+ * Do not mark this control value as updated, it does not need
+ * to be written to to device on startup.
+ */
+ values_[id][0] = Info(ctrl.second, false);
+ }
+}
+
+/**
+ * \brief Push a set of controls on the queue
+ * \param[in] controls List of controls to add to the device queue
+ *
+ * Push a set of controls to the control queue. This increases the control queue
+ * depth by one.
+ *
+ * \returns true if \a controls are accepted, or false otherwise
+ */
+bool DelayedControls::push(const ControlList &controls)
+{
+ /* Copy state from previous frame. */
+ for (auto &ctrl : values_) {
+ Info &info = ctrl.second[queueCount_];
+ info = values_[ctrl.first][queueCount_ - 1];
+ info.updated = false;
+ }
+
+ /* Update with new controls. */
+ const ControlIdMap &idmap = device_->controls().idmap();
+ for (const auto &control : controls) {
+ const auto &it = idmap.find(control.first);
+ if (it == idmap.end()) {
+ LOG(RPiDelayedControls, Warning)
+ << "Unknown control " << control.first;
+ return false;
+ }
+
+ const ControlId *id = it->second;
+
+ if (controlParams_.find(id) == controlParams_.end())
+ return false;
+
+ Info &info = values_[id][queueCount_];
+
+ info = Info(control.second);
+
+ LOG(RPiDelayedControls, Debug)
+ << "Queuing " << id->name()
+ << " to " << info.toString()
+ << " at index " << queueCount_;
+ }
+
+ queueCount_++;
+
+ return true;
+}
+
+/**
+ * \brief Read back controls in effect at a sequence number
+ * \param[in] sequence The sequence number to get controls for
+ *
+ * Read back what controls where in effect at a specific sequence number. The
+ * history is a ring buffer of 16 entries where new and old values coexist. It's
+ * the callers responsibility to not read too old sequence numbers that have been
+ * pushed out of the history.
+ *
+ * Historic values are evicted by pushing new values onto the queue using
+ * push(). The max history from the current sequence number that yields valid
+ * values are thus 16 minus number of controls pushed.
+ *
+ * \return The controls at \a sequence number
+ */
+ControlList DelayedControls::get(uint32_t sequence)
+{
+ unsigned int index = std::max<int>(0, sequence - maxDelay_);
+
+ ControlList out(device_->controls());
+ for (const auto &ctrl : values_) {
+ const ControlId *id = ctrl.first;
+ const Info &info = ctrl.second[index];
+
+ out.set(id->id(), info);
+
+ LOG(RPiDelayedControls, Debug)
+ << "Reading " << id->name()
+ << " to " << info.toString()
+ << " at index " << index;
+ }
+
+ return out;
+}
+
+/**
+ * \brief Inform DelayedControls of the start of a new frame
+ * \param[in] sequence Sequence number of the frame that started
+ *
+ * Inform the state machine that a new frame has started and of its sequence
+ * number. Any user of these helpers is responsible to inform the helper about
+ * the start of any frame. This can be connected with ease to the start of a
+ * exposure (SOE) V4L2 event.
+ */
+void DelayedControls::applyControls(uint32_t sequence)
+{
+ LOG(RPiDelayedControls, Debug) << "frame " << sequence << " started";
+
+ /*
+ * Create control list peeking ahead in the value queue to ensure
+ * values are set in time to satisfy the sensor delay.
+ */
+ ControlList out(device_->controls());
+ for (auto &ctrl : values_) {
+ const ControlId *id = ctrl.first;
+ unsigned int delayDiff = maxDelay_ - controlParams_[id].delay;
+ unsigned int index = std::max<int>(0, writeCount_ - delayDiff);
+ Info &info = ctrl.second[index];
+
+ if (info.updated) {
+ if (controlParams_[id].priorityWrite) {
+ /*
+ * This control must be written now, it could
+ * affect validity of the other controls.
+ */
+ ControlList priority(device_->controls());
+ priority.set(id->id(), info);
+ device_->setControls(&priority);
+ } else {
+ /*
+ * Batch up the list of controls and write them
+ * at the end of the function.
+ */
+ out.set(id->id(), info);
+ }
+
+ LOG(RPiDelayedControls, Debug)
+ << "Setting " << id->name()
+ << " to " << info.toString()
+ << " at index " << index;
+
+ /* Done with this update, so mark as completed. */
+ info.updated = false;
+ }
+ }
+
+ writeCount_ = sequence + 1;
+
+ while (writeCount_ > queueCount_) {
+ LOG(RPiDelayedControls, Debug)
+ << "Queue is empty, auto queue no-op.";
+ push({});
+ }
+
+ device_->setControls(&out);
+}
+
+} /* namespace RPi */
+
+} /* namespace libcamera */
diff --git a/src/libcamera/pipeline/raspberrypi/delayed_controls.h b/src/libcamera/pipeline/raspberrypi/delayed_controls.h
new file mode 100644
index 000000000000..f7f246482968
--- /dev/null
+++ b/src/libcamera/pipeline/raspberrypi/delayed_controls.h
@@ -0,0 +1,84 @@
+/* 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 <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();
+
+ bool push(const ControlList &controls);
+ ControlList 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;
+ class ControlRingBuffer : public std::array<Info, listSize>
+ {
+ public:
+ Info &operator[](unsigned int index)
+ {
+ return std::array<Info, listSize>::operator[](index % listSize);
+ }
+
+ const Info &operator[](unsigned int index) const
+ {
+ return std::array<Info, 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 *, ControlRingBuffer> values_;
+};
+
+} /* namespace RPi */
+
+} /* namespace libcamera */
diff --git a/src/libcamera/pipeline/raspberrypi/meson.build b/src/libcamera/pipeline/raspberrypi/meson.build
index f1a2f5ee72c2..6064a3f00122 100644
--- a/src/libcamera/pipeline/raspberrypi/meson.build
+++ b/src/libcamera/pipeline/raspberrypi/meson.build
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: CC0-1.0
libcamera_sources += files([
+ 'delayed_controls.cpp',
'dma_heaps.cpp',
'raspberrypi.cpp',
'rpi_stream.cpp',
--
2.25.1
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