system/dev/display/vim-display/vim-spdif-audio-stream.h

// Copyright 2018 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.

#pragma once

#include <fbl/ref_ptr.h>
#include <lib/simple-audio-stream/simple-audio-stream.h>
#include <zircon/device/audio.h>

#include "vim-audio-utils.h"

// Fwd Decls
extern "C" {
    struct vim2_display;
}

namespace audio {
namespace vim2 {

class Vim2SpdifAudioStream : public SimpleAudioStream {
  public:
    DISALLOW_COPY_ASSIGN_AND_MOVE(Vim2SpdifAudioStream);
    static void Disable(const Registers& regs);

    uint64_t display_id() const { return display_id_; }

  protected:
    friend class fbl::RefPtr<Vim2SpdifAudioStream>;
    friend class SimpleAudioStream;

    Vim2SpdifAudioStream(const vim2_display* display,
                         fbl::RefPtr<Registers> regs,
                         fbl::RefPtr<RefCountedVmo> ring_buffer_vmo,
                         fzl::PinnedVmo pinned_ring_buffer,
                         uint64_t display_id);

    ~Vim2SpdifAudioStream() override {
        Shutdown();
    }

    zx_status_t Init() __TA_REQUIRES(domain_->token()) override;
    void ShutdownHook() __TA_REQUIRES(domain_->token()) override;
    void RingBufferShutdown() __TA_REQUIRES(domain_->token()) override;

    zx_status_t ChangeFormat(const audio_proto::StreamSetFmtReq& req)
        __TA_REQUIRES(domain_->token()) override;
    zx_status_t SetGain(const audio_proto::SetGainReq& req)
        __TA_REQUIRES(domain_->token()) override;

    zx_status_t GetBuffer(const audio_proto::RingBufGetBufferReq& req,
                          uint32_t* out_num_rb_frames,
                          zx::vmo* out_buffer) __TA_REQUIRES(domain_->token()) override;
    zx_status_t Start(uint64_t* out_start_time) __TA_REQUIRES(domain_->token()) override;
    zx_status_t Stop() __TA_REQUIRES(domain_->token()) override;

  private:
    zx_status_t CreateFormatList() __TA_REQUIRES(domain_->token());

    void Enable();
    void SetupBuffer();
    void SetMode(uint32_t frame_rate, audio_sample_format_t fmt);
    void Mute(bool muted);

    // TODO(johngro) : it is unfortunate that we need to maintain an unmanaged
    // pointer back to our display in order to configure it properly when
    // setting audio modes.  In a perfect world, however, we would really not
    // know much of anything about us.  Instead, we would be able to properly
    // represent composite device drivers, and this audio code would be running
    // on its own in a separate devhost and acting as a DAI driver for various
    // codec drivers.  In this world, HDMI driver would serve as a codec driver,
    // and it would get first crack at the call to "set format", which would
    // allow it configure the audio clock recover and audio info-frame as part
    // of the process of requesting the proper DAI stream to feed the HDMI
    // transmitter unit in the chip.
    //
    // Until that day comes, however, we need a small callback hook into the
    // display driver to set this up when the high level code asks us to do so.
    // In order to do that, we need to hold the context pointer to the display
    // driver instance, which will be passed to us at construction time.  Since
    // we have no managed pointers, it is the HDMI driver's responsibility to
    // make certain that its scope outlives our.
    //
    const struct vim2_display* const display_;
    const uint64_t display_id_;

    fbl::RefPtr<Registers> regs_;
    fbl::RefPtr<RefCountedVmo> ring_buffer_vmo_;
    fzl::PinnedVmo pinned_ring_buffer_;
    uint32_t usable_buffer_size_ = 0;
};

}  // namespace vim2
}  // namespace audio