//---------------------------------------------------------------------------
//
//	SCSI Target Emulator PiSCSI
//	for Raspberry Pi
//
//  Copyright (C) 2022 akuker
//
//	[ High resolution timer ]
//
//---------------------------------------------------------------------------
#pragma once

#include "systimer.h"
#include <stdint.h>
#include <string>

//===========================================================================
//
//	System timer
//
//===========================================================================
class SysTimer_AllWinner : public PlatformSpecificTimer
{
  public:
    // Default constructor
    SysTimer_AllWinner() = default;
    // Default destructor
    ~SysTimer_AllWinner() override = default;
    // Initialization
    void Init() override;
    // Get system timer low byte
    uint32_t GetTimerLow() override;
    // Get system timer high byte
    uint32_t GetTimerHigh() override;
    // Sleep for N nanoseconds
    void SleepNsec(uint32_t nsec) override;
    // Sleep for N microseconds
    void SleepUsec(uint32_t usec) override;

  private:
    void enable_hs_timer();
    void disable_hs_timer();

    static const std::string dev_mem_filename;

    /* Reference: Allwinner H3 Datasheet, section 4.9.3 */
    static const uint32_t hs_timer_base_address = 0x01C60000;
    /* Note: Currently the high speed timer is NOT in the armbian
     * device tree. If it is ever added, this should be pulled
     * from there */

    using sun8i_hsitimer_registers = struct {
        /* 0x00 HS Timer IRQ Enabled Register */
        uint32_t hs_tmr_irq_en_reg;
        /* 0x04 HS Timer Status Register */
        uint32_t hs_tmr_irq_stat_reg;
        /* 0x08 Unused */
        uint32_t unused_08;
        /* 0x0C Unused */
        uint32_t unused_0C;
        /* 0x10 HS Timer Control Register */
        uint32_t hs_tmr_ctrl_reg;
        /* 0x14 HS Timer Interval Value Low Reg */
        uint32_t hs_tmr_intv_lo_reg;
        /* 0x18 HS Timer Interval Value High Register */
        uint32_t hs_tmr_intv_hi_reg;
        /* 0x1C HS Timer Current Value Low Register */
        uint32_t hs_tmr_curnt_lo_reg;
        /* 0x20 HS Timer Current Value High Register */
        uint32_t hs_tmr_curnt_hi_reg;
    };

    /* Constants for the HS Timer IRQ enable Register (section 4.9.4.1) */
    static const uint32_t HS_TMR_INTERUPT_ENB = (1 << 0);

    /* Constants for the HS Timer Control Register (section 4.9.4.3) */
    static const uint32_t HS_TMR_EN               = (1 << 0);
    static const uint32_t HS_TMR_RELOAD           = (1 << 1);
    static const uint32_t HS_TMR_CLK_PRE_SCALE_1  = (0 << 4);
    static const uint32_t HS_TMR_CLK_PRE_SCALE_2  = (1 << 4);
    static const uint32_t HS_TMR_CLK_PRE_SCALE_4  = (2 << 4);
    static const uint32_t HS_TMR_CLK_PRE_SCALE_8  = (3 << 4);
    static const uint32_t HS_TMR_CLK_PRE_SCALE_16 = (4 << 4); // NOSONAR This matches the datasheet
    static const uint32_t HS_TMR_MODE_SINGLE      = (1 << 7);
    static const uint32_t HS_TMR_TEST_MODE        = (1 << 31);

    volatile sun8i_hsitimer_registers *hsitimer_regs;

    /* Reference: Allwinner H3 Datasheet, section 4.3.4 */
    static const uint32_t system_bus_base_address = 0x01C20000;

    struct sun8i_sysbus_registers {
        uint32_t pad_00_5C[(0x60 / sizeof(uint32_t))]; // NOSONAR c-style array used for padding
        /* 0x0060 Bus Clock Gating Register 0 */
        uint32_t bus_clk_gating_reg0;
        uint32_t pad_64_2C0[((0x2C0 - 0x64) / sizeof(uint32_t))]; // NOSONAR c-style array used for padding
        /* 0x2C0 Bus Software Reset Register 0 */
        uint32_t bus_soft_rst_reg0;
    };

    /* Bit associated with the HS Timer */
    static const uint32_t BUS_CLK_GATING_REG0_HSTMR = 19;
    static const uint32_t BUS_SOFT_RST_REG0_HSTMR   = 19;

    struct sun8i_sysbus_registers *sysbus_regs;
};