Make libcamera to work?

device/libcamera/buffer.cc

@@ -3,7 +3,7 @@
 int libcamera_buffer_open(buffer_t *buf)
 {
   buf->libcamera = new buffer_libcamera_t{};
-  buf->libcamera->request = buf->buf_list->dev->libcamera->camera->createRequest();
+  buf->libcamera->request = buf->buf_list->dev->libcamera->camera->createRequest(buf->index);
   if (!buf->libcamera->request) {
     E_LOG_ERROR(buf, "Can't create request");
   }
@@ -53,15 +53,72 @@ void libcamera_buffer_close(buffer_t *buf)
 
 int libcamera_buffer_enqueue(buffer_t *buf, const char *who)
 {
+  auto &request = buf->libcamera->request;
+  auto const &camera = buf->buf_list->dev->libcamera->camera;
+
+  request->reuse(libcamera::Request::ReuseBuffers);
+
+  // TODO: assign timestamps
+  // for (auto const &pair : request->buffers()) {
+  //   v4l2_buf.timestamp.tv_sec = buf->captured_time_us / (1000LL * 1000LL);
+  //   v4l2_buf.timestamp.tv_usec = buf->captured_time_us % (1000LL * 1000LL);
+  // }
+
+  if (buf->buf_list->dev->libcamera->camera->queueRequest(buf->libcamera->request.get()) < 0) {
+    E_LOG_ERROR(buf, "Can't queue buffer.");
+  }
+  return 0;
+
+error:
   return -1;
 }
 
+void buffer_list_libcamera_t::libcamera_buffer_list_dequeued(libcamera::Request *request)
+{
+  E_LOG_INFO(buf_list, "Dequeued: index=%d, status=%d", request->cookie(), request->status());
+
+  if (request->status() == libcamera::Request::RequestComplete) {
+    unsigned index = request->cookie();
+    if (write(buf_list->libcamera->fds[1], &index, sizeof(index)) == sizeof(index)) {
+      return;
+    }
+  }
+
+  // put back into queue, as it failed
+  buf_list->dev->libcamera->camera->queueRequest(request);
+}
+
 int libcamera_buffer_list_dequeue(buffer_list_t *buf_list, buffer_t **bufp)
 {
-  return -1;
+  unsigned index = 0;
+  int n = read(buf_list->libcamera->fds[0], &index, sizeof(index));
+  if (n != sizeof(index)) {
+    E_LOG_INFO(buf_list, "Received invalid result from `read`: %d", n);
+    return -1;
+  }
+
+  if (index >= buf_list->nbufs) {
+    E_LOG_INFO(buf_list, "Received invalid index from `read`: %d >= %d", index, buf_list->nbufs);
+    return -1;
+  }
+
+  *bufp = buf_list->bufs[index];
+
+  // TODO: fix timestamps
+  // buf->v4l2->flags = v4l2_buf.flags;
+  // buf->flags.is_keyframe = (v4l2_buf.flags & V4L2_BUF_FLAG_KEYFRAME) != 0;
+  // buf->captured_time_us = get_time_us(CLOCK_FROM_PARAMS, NULL, &v4l2_buf.timestamp, 0);
+  return 0;
 }
 
 int libcamera_buffer_list_pollfd(buffer_list_t *buf_list, struct pollfd *pollfd, bool can_dequeue)
 {
-  return -1;
+  int count_enqueued = buffer_list_count_enqueued(buf_list);
+  pollfd->fd = buf_list->libcamera->fds[0]; // write end
+  pollfd->events = POLLHUP;
+  if (can_dequeue && count_enqueued > 0) {
+    pollfd->events |= POLLIN;
+  }
+  pollfd->revents = 0;
+  return 0;
 }

device/libcamera/buffer_list.cc

@@ -15,9 +15,18 @@ int libcamera_buffer_list_open(buffer_list_t *buf_list, unsigned width, unsigned
   }
 
   buf_list->libcamera = new buffer_list_libcamera_t{};
+  buf_list->libcamera->buf_list = buf_list;
+  buf_list->libcamera->fds[0] = -1;
+  buf_list->libcamera->fds[1] = -1;
+
+  if (pipe2(buf_list->libcamera->fds, O_DIRECT|O_CLOEXEC) < 0) {
+    E_LOG_INFO(buf_list, "Cannot open `pipe2`.");
+    return -1;
+  }
+
   buf_list->libcamera->configuration = buf_list->dev->libcamera->camera->generateConfiguration(
     { libcamera::StreamRole::Viewfinder });
-  
+
   auto &configuration = buf_list->libcamera->configuration->at(0);
   configuration.size = libcamera::Size(width, height);
   configuration.pixelFormat = libcamera::PixelFormat(format);
@@ -64,6 +73,9 @@ error:
 void libcamera_buffer_list_close(buffer_list_t *buf_list)
 {
   if (buf_list->libcamera) {
+    close(buf_list->libcamera->fds[0]);
+    close(buf_list->libcamera->fds[1]);
+
     delete buf_list->libcamera;
     buf_list->libcamera = NULL;
   }
@@ -72,10 +84,16 @@ void libcamera_buffer_list_close(buffer_list_t *buf_list)
 int libcamera_buffer_list_set_stream(buffer_list_t *buf_list, bool do_on)
 {
   if (do_on) {
+    buf_list->dev->libcamera->camera->requestCompleted.connect(
+      buf_list->libcamera, &buffer_list_libcamera_t::libcamera_buffer_list_dequeued);
+
     if (buf_list->dev->libcamera->camera->start() < 0) {
       E_LOG_ERROR(buf_list, "Failed to start camera.");
     }
   } else {
+    buf_list->dev->libcamera->camera->requestCompleted.disconnect(
+      buf_list->libcamera, &buffer_list_libcamera_t::libcamera_buffer_list_dequeued);
+
     if (buf_list->dev->libcamera->camera->stop() < 0) {
       E_LOG_ERROR(buf_list, "Failed to stop camera.");
     }

device/libcamera/libcamera.hh

@@ -42,6 +42,10 @@ typedef struct device_libcamera_s {
 typedef struct buffer_list_libcamera_s {
   std::shared_ptr<libcamera::CameraConfiguration> configuration;
   std::shared_ptr<libcamera::FrameBufferAllocator> allocator;
+  buffer_list_t *buf_list;
+  int fds[2];
+
+  void libcamera_buffer_list_dequeued(libcamera::Request *request);
 } buffer_list_libcamera_t;
 
 typedef struct buffer_libcamera_s {
@@ -58,6 +62,7 @@ int libcamera_device_set_option(device_t *dev, const char *key, const char *valu
 int libcamera_buffer_open(buffer_t *buf);
 void libcamera_buffer_close(buffer_t *buf);
 int libcamera_buffer_enqueue(buffer_t *buf, const char *who);
+void libcamera_buffer_list_dequeued(buffer_list_t *buf_list, libcamera::Request *request);
 int libcamera_buffer_list_dequeue(buffer_list_t *buf_list, buffer_t **bufp);
 int libcamera_buffer_list_pollfd(buffer_list_t *buf_list, struct pollfd *pollfd, bool can_dequeue);