[libcamera-devel] [PATCH v6 1/8] pipeline: raspberrypi: Fork DelayedControls
David Plowman
david.plowman at raspberrypi.com
Tue Nov 15 14:44:38 CET 2022
Hi Naush
Thanks for the update.
On Tue, 15 Nov 2022 at 09:08, Naushir Patuck via libcamera-devel
<libcamera-devel at lists.libcamera.org> wrote:
>
> 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>
Reviewed-by: David Plowman <david.plowman at raspberrypi.com>
I assume it's actually all a cut'n'paste job in any case!
Thanks
David
> ---
> .../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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