system/dev/display/mt8167s-display/ovl.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 <lib/zx/bti.h>
#include <zircon/compiler.h>
#include <ddk/protocol/platform/device.h>
#include <ddk/protocol/platform-device-lib.h>
#include <zircon/assert.h>
#include <ddktl/device.h>
#include <ddktl/mmio.h>
#include <fbl/unique_ptr.h>
#include <optional>
#include "common.h"
#include "registers-ovl.h"

namespace mt8167s_display {

// [Ovl] --> [Clr] --> [Clr Correction] --> [AAL] --> [Gamma] --> [Dither] --> [RDMA] --> [DSI]

//
// Overlay class is the first element in the display subsystem. It is responsible
// for fetching pixels from memory, perform blending (up to 4 layers), support RGB and UYVY
// swapping, fixed color conversion coefficient (T601, T709, JPEG), alpha blending and flipping
// (veritical, horizontal, 180-degree flip). The supported memory source formats are as follows:
// RGB565, RGB888, ARGB8888, PARGB8888, XRGB, YUV422
// Single Ovl object will manage all four layers
//
constexpr uint32_t kMaxLayer = 4;

class Ovl {
public:
    // Contructor
    Ovl(uint32_t height, uint32_t width)
        : height_(height), width_(width) {
        ZX_ASSERT(height_ < kMaxHeight);
        ZX_ASSERT(width_ < kMaxWidth);
    }

    // Init
    zx_status_t Init(zx_device_t* parent);

    // Stops the overlay engine and resets the active layers
    void Reset();

    // Configure the corresponding layer. Should only be called after Stop has been called
    zx_status_t Config(uint8_t layer, OvlConfig &cfg);

    // Start OVL engine. This will enable interrupts (VSync) and the Overalay engine itself
    void Start();

    // Stop OVL engine. This will place the Overlay engine in Idle mode and safely stop all
    // transactions that may be happening. This function should be called before configuring
    // the Overlay engine with new parameters
    void Stop();

    void Restart() {
        Stop();
        Start();
    }

    // Clears all IRQ sources
    void ClearIrq() {
        ovl_mmio_->Write32(0x0, OVL_INTSTA);
    }

    // Returns true if interrupt was not spurious
    bool IsValidIrq() {
        return ovl_mmio_->Read32(OVL_INTSTA) != 0;
    }

    // Return true if the input layer is active
    bool IsLayerActive(uint8_t layer) {
        return ((active_layers_ & (1 << layer)) != 0);
    }

    // Clears the active layer
    void ClearLayer(uint8_t layer) {
        active_layers_ &= static_cast<uint8_t>(~(1 << layer));
    }

    // Returns the layer handle which is the physical address of the VMO backed image
    zx_paddr_t GetLayerHandle(uint8_t layer) {
        return layer_handle_[layer];
    }

    // Prints the relevant status registers in the Overlay Engine
    void PrintStatusRegisters() {
        DISP_INFO("STA = 0x%x, INTSTA = 0x%x, FLOW_CTRL_DBG = 0x%x\n",
                   ovl_mmio_->Read32(OVL_STA),
                   ovl_mmio_->Read32(OVL_INTSTA),
                   ovl_mmio_->Read32(OVL_FLOW_CTRL_DBG));
    }

    // Return true is Overlay Engine is Idle
    bool IsIdle() {
        return (ovl_mmio_->Read32(OVL_FLOW_CTRL_DBG) & (OVL_IDLE)) == (OVL_IDLE);
    }

    // Dumps all relevant Overlay Registers
    void Dump();

private:

    // Overlay support ARGB, RGB and YUV formats only
    bool IsSupportedFormat(zx_pixel_format_t format);

    // Return format as expected by OVL register
    uint32_t GetFormat(zx_pixel_format_t format);

    // BYTE_SWAP: Determines the need for swapping bytes based on format
    bool ByteSwapNeeded(zx_pixel_format_t format);

    // get Bytes per Pixel.
    // TODO(payam): ZX_PIXEL_FORMAT_BYTES returns 4 for x888. We need three
    uint32_t GetBytesPerPixel(zx_pixel_format_t format);

    fbl::unique_ptr<ddk::MmioBuffer>    ovl_mmio_;
    pdev_protocol_t                     pdev_ = {nullptr, nullptr};
    zx::bti                             bti_;

    const uint32_t                      height_; // Display height
    const uint32_t                      width_; // Display width

    bool                                initialized_ = false;

    uint8_t                             active_layers_ = 0;
    zx_paddr_t                          layer_handle_[kMaxLayer] = {};
};

} // namespace mt8167s_display