zircon/system/banjo/ddk.protocol.gdc/gdc.banjo

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library ddk.protocol.gdc;
using zx;
using zircon.device.sysmem;


[Layout = "ddk-callback"]
protocol GdcCallback {
    // This is called by the GDC driver, every time a frame is ready to be
    // consumed.
    FrameReady(uint32 buffer_index);
};

[Layout = "ddk-protocol"]
protocol Gdc {
    // Registers the buffer collections and configuration which the GDC will be using
    // for this task and also the callback functions for a particular task and
    // returns a task index.
    // |input_buffer_collection| : Pool of VMOs as input to the GDC.
    // |output_buffer_collection| : Pool of VMOs as output to the GDC.
    // |config_vmo| : Static configuration for GDC is stored in this vmo for this task.
    // |callback| : This function is called when GDC is done processing the task.
    // @Returns: |task_index| : Task ID for this task.
    InitTask(zircon.device.sysmem.BufferCollectionInfo input_buffer_collection,
             zircon.device.sysmem.BufferCollectionInfo output_buffer_collection,
             handle<vmo> config_vmo,
             GdcCallback callback) -> (zx.status s, uint32 task_index);

    // De-registers the task.
    RemoveTask(uint32 task_index);

    // Processes the frame at |input_buffer_index| within |input_buffer_collection|
    // in the task corresponding to |task_index| and stores the ouput in the
    // |output_buffer_collection| after applying the correct configuration.
    // After processing we call the callback registered for this task with the
    // output buffer index.
    ProcessFrame(uint32 task_index, uint32 input_buffer_index) -> (zx.status s);

    // Releases the frame |buffer_index| from the |output_buffer_collection| to be
    // used again by GDC driver again later.
    ReleaseFrame(uint32 task_index, uint32 buffer_index);
};