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Diffstat (limited to 'src/libcamera/pipeline/rpi/common/delayed_controls.cpp')
| -rw-r--r-- | src/libcamera/pipeline/rpi/common/delayed_controls.cpp | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/libcamera/pipeline/rpi/common/delayed_controls.cpp b/src/libcamera/pipeline/rpi/common/delayed_controls.cpp new file mode 100644 index 00000000..3db92e7d --- /dev/null +++ b/src/libcamera/pipeline/rpi/common/delayed_controls.cpp @@ -0,0 +1,293 @@ +/* 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(0); +} + +/** + * \brief Reset state machine + * + * Resets the state machine to a starting position based on control values + * retrieved from the device. + */ +void DelayedControls::reset(unsigned int cookie) +{ + queueCount_ = 1; + writeCount_ = 0; + cookies_[0] = cookie; + + /* 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, const unsigned int cookie) +{ + /* 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_; + } + + cookies_[queueCount_] = cookie; + 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 + */ +std::pair<ControlList, unsigned int> 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, cookies_[index] }; +} + +/** + * \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({}, cookies_[queueCount_ - 1]); + } + + device_->setControls(&out); +} + +} /* namespace RPi */ + +} /* namespace libcamera */ |