[libcamera-devel] [PATCH v2 6/8] cam: Add KMS sink class
paul.elder at ideasonboard.com
paul.elder at ideasonboard.com
Wed Aug 4 08:56:18 CEST 2021
Hi Laurent,
On Fri, Jul 30, 2021 at 04:03:04AM +0300, Laurent Pinchart wrote:
> Add a KMSSink class to display framebuffers through the DRM/KMS API.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> Changes since v1:
>
> - Use formats:: namespace
> ---
> src/cam/kms_sink.cpp | 298 +++++++++++++++++++++++++++++++++++++++++++
> src/cam/kms_sink.h | 76 +++++++++++
> src/cam/meson.build | 1 +
> 3 files changed, 375 insertions(+)
> create mode 100644 src/cam/kms_sink.cpp
> create mode 100644 src/cam/kms_sink.h
>
> diff --git a/src/cam/kms_sink.cpp b/src/cam/kms_sink.cpp
> new file mode 100644
> index 000000000000..b8f86dcb6f4e
> --- /dev/null
> +++ b/src/cam/kms_sink.cpp
> @@ -0,0 +1,298 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2020, Ideas on Board Oy
s/2020/2021 ?
Same for the header.
> + *
> + * kms_sink.cpp - KMS Sink
> + */
> +
> +#include "kms_sink.h"
> +
> +#include <algorithm>
> +#include <assert.h>
> +#include <iostream>
> +#include <memory>
> +#include <string.h>
> +
> +#include <libcamera/camera.h>
> +#include <libcamera/formats.h>
> +#include <libcamera/framebuffer.h>
> +#include <libcamera/stream.h>
> +
> +#include "drm.h"
> +
> +KMSSink::KMSSink(const std::string &connectorName)
> + : connector_(nullptr), crtc_(nullptr), plane_(nullptr), mode_(nullptr)
> +{
> + int ret = dev_.init();
> + if (ret < 0)
> + return;
> +
> + /*
> + * Find the requested connector. If no connector is requested, pick the
> + * first connected connector.
> + */
> + for (const DRM::Connector &conn : dev_.connectors()) {
> + if (conn.name() == connectorName) {
> + connector_ = &conn;
> + break;
> + }
> +
> + if (conn.status() != DRM::Connector::Disconnected) {
> + if (!connector_ ||
> + (connector_->status() == DRM::Connector::Unknown &&
> + conn.status() == DRM::Connector::Connected))
> + connector_ = &conn;
> + }
I think this is the only part I'm confused about. If no connector is
requested, then the first candidate connector can be chosen even if its
status is Unknown.
Paul
> + }
> +
> + if (!connector_) {
> + if (!connectorName.empty())
> + std::cerr
> + << "Connector " << connectorName << " not found"
> + << std::endl;
> + else
> + std::cerr << "No connected connector found" << std::endl;
> + return;
> + }
> +
> + dev_.requestComplete.connect(this, &KMSSink::requestComplete);
> +}
> +
> +void KMSSink::mapBuffer(libcamera::FrameBuffer *buffer)
> +{
> + std::unique_ptr<DRM::FrameBuffer> drmBuffer =
> + dev_.createFrameBuffer(*buffer, format_, size_, stride_);
> + if (!drmBuffer)
> + return;
> +
> + buffers_.emplace(std::piecewise_construct,
> + std::forward_as_tuple(buffer),
> + std::forward_as_tuple(std::move(drmBuffer)));
> +}
> +
> +int KMSSink::configure(const libcamera::CameraConfiguration &config)
> +{
> + crtc_ = nullptr;
> + plane_ = nullptr;
> + mode_ = nullptr;
> +
> + const libcamera::StreamConfiguration &cfg = config.at(0);
> + int ret = configurePipeline(cfg.pixelFormat);
> + if (ret < 0)
> + return ret;
> +
> + const std::vector<DRM::Mode> &modes = connector_->modes();
> + const auto iter = std::find_if(modes.begin(), modes.end(),
> + [&](const DRM::Mode &mode) {
> + return mode.hdisplay == cfg.size.width &&
> + mode.vdisplay == cfg.size.height;
> + });
> + if (iter == modes.end()) {
> + std::cerr
> + << "No mode matching " << cfg.size.toString()
> + << std::endl;
> + return -EINVAL;
> + }
> +
> + mode_ = &*iter;
> + size_ = cfg.size;
> + stride_ = cfg.stride;
> +
> + return 0;
> +}
> +
> +int KMSSink::configurePipeline(const libcamera::PixelFormat &format)
> +{
> + /*
> + * If the requested format has an alpha channel, also consider the X
> + * variant.
> + */
> + libcamera::PixelFormat xFormat;
> +
> + switch (format) {
> + case libcamera::formats::ABGR8888:
> + xFormat = libcamera::formats::XBGR8888;
> + break;
> + case libcamera::formats::ARGB8888:
> + xFormat = libcamera::formats::XRGB8888;
> + break;
> + case libcamera::formats::BGRA8888:
> + xFormat = libcamera::formats::BGRX8888;
> + break;
> + case libcamera::formats::RGBA8888:
> + xFormat = libcamera::formats::RGBX8888;
> + break;
> + }
> +
> + /*
> + * Find a CRTC and plane suitable for the request format and the
> + * connector at the end of the pipeline. Restrict the search to primary
> + * planes for now.
> + */
> + for (const DRM::Encoder *encoder : connector_->encoders()) {
> + for (const DRM::Crtc *crtc : encoder->possibleCrtcs()) {
> + for (const DRM::Plane *plane : crtc->planes()) {
> + if (plane->type() != DRM::Plane::TypePrimary)
> + continue;
> +
> + if (plane->supportsFormat(format)) {
> + crtc_ = crtc;
> + plane_ = plane;
> + format_ = format;
> + return 0;
> + }
> +
> + if (plane->supportsFormat(xFormat)) {
> + crtc_ = crtc;
> + plane_ = plane;
> + format_ = xFormat;
> + return 0;
> + }
> + }
> + }
> + }
> +
> + std::cerr
> + << "Unable to find display pipeline for format "
> + << format.toString() << std::endl;
> + return -EPIPE;
> +}
> +
> +int KMSSink::start()
> +{
> + std::unique_ptr<DRM::AtomicRequest> request;
> +
> + int ret = FrameSink::start();
> + if (ret < 0)
> + return ret;
> +
> + /* Disable all CRTCs and planes to start from a known valid state. */
> + request = std::make_unique<DRM::AtomicRequest>(&dev_);
> +
> + for (const DRM::Crtc &crtc : dev_.crtcs())
> + request->addProperty(&crtc, "ACTIVE", 0);
> +
> + for (const DRM::Plane &plane : dev_.planes()) {
> + request->addProperty(&plane, "CRTC_ID", 0);
> + request->addProperty(&plane, "FB_ID", 0);
> + }
> +
> + ret = request->commit(DRM::AtomicRequest::FlagAllowModeset);
> + if (ret < 0) {
> + std::cerr
> + << "Failed to disable CRTCs and planes: "
> + << strerror(-ret) << std::endl;
> + return ret;
> + }
> +
> + /* Enable the display pipeline with no plane to start with. */
> + request = std::make_unique<DRM::AtomicRequest>(&dev_);
> +
> + request->addProperty(connector_, "CRTC_ID", crtc_->id());
> + request->addProperty(crtc_, "ACTIVE", 1);
> + request->addProperty(crtc_, "MODE_ID", mode_->toBlob(&dev_));
> +
> + ret = request->commit(DRM::AtomicRequest::FlagAllowModeset);
> + if (ret < 0) {
> + std::cerr
> + << "Failed to enable display pipeline: "
> + << strerror(-ret) << std::endl;
> + return ret;
> + }
> +
> + planeInitialized_ = false;
> +
> + return 0;
> +}
> +
> +int KMSSink::stop()
> +{
> + /* Display pipeline. */
> + DRM::AtomicRequest request(&dev_);
> +
> + request.addProperty(connector_, "CRTC_ID", 0);
> + request.addProperty(crtc_, "ACTIVE", 0);
> + request.addProperty(crtc_, "MODE_ID", 0);
> + request.addProperty(plane_, "CRTC_ID", 0);
> + request.addProperty(plane_, "FB_ID", 0);
> +
> + int ret = request.commit(DRM::AtomicRequest::FlagAllowModeset);
> + if (ret < 0) {
> + std::cerr
> + << "Failed to stop display pipeline: "
> + << strerror(-ret) << std::endl;
> + return ret;
> + }
> +
> + /* Free all buffers. */
> + pending_.reset();
> + queued_.reset();
> + active_.reset();
> + buffers_.clear();
> +
> + return FrameSink::stop();
> +}
> +
> +bool KMSSink::consumeRequest(libcamera::Request *camRequest)
> +{
> + if (pending_)
> + return true;
> +
> + libcamera::FrameBuffer *buffer = camRequest->buffers().begin()->second;
> + auto iter = buffers_.find(buffer);
> + if (iter == buffers_.end())
> + return true;
> +
> + DRM::FrameBuffer *drmBuffer = iter->second.get();
> +
> + DRM::AtomicRequest *drmRequest = new DRM::AtomicRequest(&dev_);
> + drmRequest->addProperty(plane_, "FB_ID", drmBuffer->id());
> +
> + if (!planeInitialized_) {
> + drmRequest->addProperty(plane_, "CRTC_ID", crtc_->id());
> + drmRequest->addProperty(plane_, "SRC_X", 0 << 16);
> + drmRequest->addProperty(plane_, "SRC_Y", 0 << 16);
> + drmRequest->addProperty(plane_, "SRC_W", mode_->hdisplay << 16);
> + drmRequest->addProperty(plane_, "SRC_H", mode_->vdisplay << 16);
> + drmRequest->addProperty(plane_, "CRTC_X", 0);
> + drmRequest->addProperty(plane_, "CRTC_Y", 0);
> + drmRequest->addProperty(plane_, "CRTC_W", mode_->hdisplay);
> + drmRequest->addProperty(plane_, "CRTC_H", mode_->vdisplay);
> + planeInitialized_ = true;
> + }
> +
> + pending_ = std::make_unique<Request>(drmRequest, camRequest);
> +
> + std::lock_guard<std::mutex> lock(lock_);
> +
> + if (!queued_) {
> + int ret = drmRequest->commit(DRM::AtomicRequest::FlagAsync);
> + if (ret < 0)
> + std::cerr
> + << "Failed to commit atomic request: "
> + << strerror(-ret) << std::endl;
> + queued_ = std::move(pending_);
> + }
> +
> + return false;
> +}
> +
> +void KMSSink::requestComplete(DRM::AtomicRequest *request)
> +{
> + std::lock_guard<std::mutex> lock(lock_);
> +
> + assert(queued_ && queued_->drmRequest_.get() == request);
> +
> + /* Complete the active request, if any. */
> + if (active_)
> + requestReleased.emit(active_->camRequest_);
> +
> + /* The queued request becomes active. */
> + active_ = std::move(queued_);
> +
> + /* Queue the pending request, if any. */
> + if (pending_) {
> + pending_->drmRequest_->commit(DRM::AtomicRequest::FlagAsync);
> + queued_ = std::move(pending_);
> + }
> +}
> diff --git a/src/cam/kms_sink.h b/src/cam/kms_sink.h
> new file mode 100644
> index 000000000000..7b6ffcede28c
> --- /dev/null
> +++ b/src/cam/kms_sink.h
> @@ -0,0 +1,76 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2020, Ideas on Board Oy
> + *
> + * kms_sink.h - KMS Sink
> + */
> +#ifndef __CAM_KMS_SINK_H__
> +#define __CAM_KMS_SINK_H__
> +
> +#include <list>
> +#include <memory>
> +#include <mutex>
> +#include <string>
> +#include <utility>
> +
> +#include <libcamera/base/signal.h>
> +
> +#include <libcamera/geometry.h>
> +#include <libcamera/pixel_format.h>
> +
> +#include "drm.h"
> +#include "frame_sink.h"
> +
> +class KMSSink : public FrameSink
> +{
> +public:
> + KMSSink(const std::string &connectorName);
> +
> + bool isValid() const { return connector_ != nullptr; }
> +
> + void mapBuffer(libcamera::FrameBuffer *buffer) override;
> +
> + int configure(const libcamera::CameraConfiguration &config) override;
> + int start() override;
> + int stop() override;
> +
> + bool consumeRequest(libcamera::Request *request) override;
> +
> +private:
> + class Request
> + {
> + public:
> + Request(DRM::AtomicRequest *drmRequest, libcamera::Request *camRequest)
> + : drmRequest_(drmRequest), camRequest_(camRequest)
> + {
> + }
> +
> + std::unique_ptr<DRM::AtomicRequest> drmRequest_;
> + libcamera::Request *camRequest_;
> + };
> +
> + int configurePipeline(const libcamera::PixelFormat &format);
> + void requestComplete(DRM::AtomicRequest *request);
> +
> + DRM::Device dev_;
> +
> + const DRM::Connector *connector_;
> + const DRM::Crtc *crtc_;
> + const DRM::Plane *plane_;
> + const DRM::Mode *mode_;
> +
> + libcamera::PixelFormat format_;
> + libcamera::Size size_;
> + unsigned int stride_;
> +
> + bool planeInitialized_;
> +
> + std::map<libcamera::FrameBuffer *, std::unique_ptr<DRM::FrameBuffer>> buffers_;
> +
> + std::mutex lock_;
> + std::unique_ptr<Request> pending_;
> + std::unique_ptr<Request> queued_;
> + std::unique_ptr<Request> active_;
> +};
> +
> +#endif /* __CAM_KMS_SINK_H__ */
> diff --git a/src/cam/meson.build b/src/cam/meson.build
> index b47add55b0cb..ea36aaa5c514 100644
> --- a/src/cam/meson.build
> +++ b/src/cam/meson.build
> @@ -27,6 +27,7 @@ if libdrm.found()
> cam_cpp_args += [ '-DHAVE_KMS' ]
> cam_sources += files([
> 'drm.cpp',
> + 'kms_sink.cpp'
> ])
> endif
>
> --
> Regards,
>
> Laurent Pinchart
>
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