/*----------------------------------------------------------------------------/
  Lovyan GFX - Graphics library for embedded devices.

Original Source:
 https://github.com/lovyan03/LovyanGFX/

Licence:
 [FreeBSD](https://github.com/lovyan03/LovyanGFX/blob/master/license.txt)

Author:
 [lovyan03](https://twitter.com/lovyan03)

Contributors:
 [ciniml](https://github.com/ciniml)
 [mongonta0716](https://github.com/mongonta0716)
 [tobozo](https://github.com/tobozo)

Porting for RP2040:
 [yasuhirok](https://github.com/yasuhirok-git)
/----------------------------------------------------------------------------*/
#if defined (ARDUINO_ARCH_MBED_RP2040) || defined(ARDUINO_ARCH_RP2040) || defined(USE_PICO_SDK)

#include "common.hpp"
#include <array>
#include <unordered_map>

#include <hardware/structs/resets.h>
#include <hardware/structs/padsbank0.h>
#include <hardware/structs/sio.h>
#include <hardware/structs/iobank0.h>
#include <hardware/sync.h>
#include <hardware/resets.h>
#include <hardware/clocks.h>
#include <hardware/gpio.h>
#include <hardware/spi.h>
#include <hardware/i2c.h>


#if PICO_SDK_VERSION_MAJOR<2
  // NOTE: old pico sdk (before rp2350) used enum type for gpio function, iobank was named differently too
  #define gpio_function_t enum gpio_function
  #define io_bank0_hw_t iobank0_hw_t
#endif

// #define DEBUG

#if defined(DEBUG)
#include <DebugUtil.hpp>
#else
#define DBGPRINT(fmt, ...)
#define DBG_ENTER()
#define DBGPRINTFUNC(fmt, ...)
#define put_dump_byte(data, addr, length)
#endif

// 参考:
// https://os.mbed.com/docs/mbed-os/v6.15/mbed-os-api-doxy/group__hal__gpio.html
// https://github.com/arduino/ArduinoCore-mbed/releases
// https://github.com/raspberrypi/pico-sdk

namespace lgfx
{
 inline namespace v1
 {
  namespace rp2040
  {
    static bool pin_check(int pin, const uint8_t *pinlist)
    {
      int idx = 0;
      while (pinlist[idx] != static_cast<int>(UINT8_MAX))
      {
        if (static_cast<int>(pinlist[idx]) == pin)
        {
          return true;
        }
        idx++;
      }
      return false;
    }
  }

  namespace {

    bool lgfx_gpio_set_function(int_fast16_t pin, gpio_function_t fn)
    {
      if (pin < 0 || pin >= static_cast<int_fast16_t>(NUM_BANK0_GPIOS))
      {
        return false;
      }
      if ((((uint32_t)fn << IO_BANK0_GPIO0_CTRL_FUNCSEL_LSB) & ~IO_BANK0_GPIO0_CTRL_FUNCSEL_BITS) != 0)
      {
        return false;
      }
      uint32_t temp = padsbank0_hw->io[pin];
      temp &= ~(PADS_BANK0_GPIO0_IE_BITS | PADS_BANK0_GPIO0_OD_BITS);
      temp |= PADS_BANK0_GPIO0_IE_BITS;
      padsbank0_hw->io[pin] = temp;
      volatile io_bank0_hw_t *iobank0_regs = reinterpret_cast<volatile io_bank0_hw_t *>(IO_BANK0_BASE);
      iobank0_regs->io[pin].ctrl = fn << IO_BANK0_GPIO0_CTRL_FUNCSEL_LSB;
      #if defined(PICO_RP2350)
        // Remove pad isolation now that the correct peripheral is in control of the pad
        hw_clear_bits(&padsbank0_hw->io[pin], PADS_BANK0_GPIO0_ISO_BITS);
      #endif
      return true;
    }

    bool lgfx_gpio_init(int_fast16_t pin)
    {
      if (pin < 0 || pin >= static_cast<int_fast16_t>(NUM_BANK0_GPIOS))
      {
        return false;
      }
      return lgfx_gpio_set_function(pin, GPIO_FUNC_SIO);
    }

    __attribute__ ((always_inline)) inline void lgfx_gpio_set_pulls(int_fast16_t pin, bool up, bool down)
    {
      uint32_t temp = padsbank0_hw->io[pin];
      temp &= ~(PADS_BANK0_GPIO0_PUE_BITS | PADS_BANK0_GPIO0_PDE_BITS);
      temp |= (((up ? 1U : 0U) << PADS_BANK0_GPIO0_PUE_LSB) | ((down ? 1U : 0U) << PADS_BANK0_GPIO0_PDE_LSB));
    }

    __attribute__ ((always_inline)) inline void lgfx_gpio_pull_up(int_fast16_t pin)
    {
      lgfx_gpio_set_pulls(pin, true, false);
    }

    __attribute__ ((always_inline)) inline void lgfx_gpio_pull_down(int_fast16_t pin)
    {
      lgfx_gpio_set_pulls(pin, false, true);
    }

    __attribute__ ((always_inline)) inline void lgfx_gpio_disable_pulls(int_fast16_t pin)
    {
      lgfx_gpio_set_pulls(pin, false, false);
    }

    bool lgfx_gpio_mode(int_fast16_t pin, pin_mode_t mode)
    {
      if (pin < 0 || pin >= static_cast<int_fast16_t>(NUM_BANK0_GPIOS))
      {
        return false;
      }
      bool rc = false;
      switch (mode)
      {
      case pin_mode_t::output:
        [[fallthrough]];
      case pin_mode_t::input:
        lgfx_gpio_disable_pulls(pin);
        rc = true;
        break;
      case pin_mode_t::input_pullup:
        lgfx_gpio_pull_up(pin);
        rc = true;
        break;
      case pin_mode_t::input_pulldown:
        lgfx_gpio_pull_down(pin);
        rc = true;
        break;
      default:
        break;
      }
      return rc;
    }

    bool lgfx_gpio_set_dir(int_fast16_t pin, bool out)
    {
      if (pin < 0 || pin >= static_cast<int_fast16_t>(NUM_BANK0_GPIOS))
      {
        return false;
      }
      const uint32_t mask = 1UL << pin;
      if (out)
      {
        sio_hw->gpio_oe_set = mask;
      }
      else
      {
        sio_hw->gpio_oe_clr = mask;
      }
      return true;
    }

    __attribute__ ((always_inline)) inline void lgfx_reset_block(uint32_t bits)
    {
      reset_block(bits);
    }

    __attribute__((always_inline)) inline void lgfx_unreset_block_wait(uint32_t bits)
    {
      unreset_block_wait(bits);
    }
  }

  void pinMode(int_fast16_t pin, pin_mode_t mode)
  {
    if (pin < 0 || pin >= static_cast<int_fast16_t>(NUM_BANK0_GPIOS))
    {
      return;
    }
    lgfx_gpio_init(pin);
    lgfx_gpio_mode(pin, mode);
    lgfx_gpio_set_dir(pin, mode == pin_mode_t::output);
  }

//----------------------------------------------------------------------------

  namespace spi
  {
    namespace
    {
      struct spi_info_str {
        uint32_t ref_count { 0 };
        int pin_sclk { -1 };
        int pin_miso { -1 };
        int pin_mosi { -1 };
      };

      volatile spi_hw_t * const spi_dev[] = {
        reinterpret_cast<volatile spi_hw_t *>(SPI0_BASE),
        reinterpret_cast<volatile spi_hw_t *>(SPI1_BASE),
      };
      constexpr int n_spi = std::extent<decltype(spi_dev), 0>::value;

#if defined(PICO_RP2350)
      // RP2350 Dataheetの 9.4. Function Select (Table 642)を参照
      // ※30以降は2350Bで使用可能
      constexpr uint8_t spi0_sclk_pinlist[] = {  2,  6, 18, 22, 34, 38,     UINT8_MAX };
      constexpr uint8_t spi0_miso_pinlist[] = {  0,  4, 16, 20, 32, 36,     UINT8_MAX };
      constexpr uint8_t spi0_mosi_pinlist[] = {  3,  7, 19, 23, 35, 39,     UINT8_MAX };
      constexpr uint8_t spi1_sclk_pinlist[] = { 10, 14, 26,     30, 42, 46, UINT8_MAX };
      constexpr uint8_t spi1_miso_pinlist[] = {  8, 12, 24, 28, 40, 44,     UINT8_MAX };
      constexpr uint8_t spi1_mosi_pinlist[] = { 11, 15, 27,     31, 43, 47, UINT8_MAX };
#else
      // RP2040 Dataheetの 1.4.3. GPIO Functions Table 2を参照
      constexpr uint8_t spi0_sclk_pinlist[] = {  2,  6, 18, 22, UINT8_MAX };
      constexpr uint8_t spi0_miso_pinlist[] = {  0,  4, 16, 20, UINT8_MAX };
      constexpr uint8_t spi0_mosi_pinlist[] = {  3,  7, 19, 23, UINT8_MAX };
      constexpr uint8_t spi1_sclk_pinlist[] = { 10, 14, 26,     UINT8_MAX };
      constexpr uint8_t spi1_miso_pinlist[] = {  8, 12, 24, 28, UINT8_MAX };
      constexpr uint8_t spi1_mosi_pinlist[] = { 11, 15, 27,     UINT8_MAX };
#endif

      constexpr uint32_t PRESCALE_ERROR = UINT32_MAX;

      //
      constexpr struct spi_pinlist_str {
        const uint8_t *sclk_pinlist;
        const uint8_t *miso_pinlist;
        const uint8_t *mosi_pinlist;
      } spi_pinlist[] = {
        {
          .sclk_pinlist = spi0_sclk_pinlist,
          .miso_pinlist = spi0_miso_pinlist,
          .mosi_pinlist = spi0_mosi_pinlist,
        },
        {
          .sclk_pinlist = spi1_sclk_pinlist,
          .miso_pinlist = spi1_miso_pinlist,
          .mosi_pinlist = spi1_mosi_pinlist,
        },
      };

      spi_info_str spi_info[n_spi];
    }

//----------------------------------------------------------------------------

    uint32_t FreqToClockDiv(uint32_t hz)
    {
      uint32_t fapb = clock_get_hz(clk_peri) >> 1;
      if (fapb <= hz) return 0;
      uint32_t div_num = fapb / (1 + hz);
      if (div_num > 255) div_num = 255;
      return div_num;
    }
    namespace
    {

      __attribute__ ((always_inline)) inline void lgfx_spi_reset(volatile spi_hw_t * spi_regs)
      {
        lgfx_reset_block((spi_regs == spi_dev[0]) ? RESETS_RESET_SPI0_BITS : RESETS_RESET_SPI1_BITS);
      }

      __attribute__ ((always_inline)) inline void lgfx_spi_unreset(volatile spi_hw_t * spi_regs)
      {
        lgfx_unreset_block_wait((spi_regs == spi_dev[0]) ? RESETS_RESET_SPI0_BITS : RESETS_RESET_SPI1_BITS);
      }

      static uint32_t last_clock_div = 1;

      bool lgfx_spi_set_baudrate(volatile spi_hw_t * spi_regs, uint32_t baudrate)
      {
        spi_regs->cpsr = 2;  // prescale
        last_clock_div = FreqToClockDiv(baudrate);

        uint32_t temp = spi_regs->cr0;
        temp &= ~SPI_SSPCR0_SCR_BITS;
        temp |= (last_clock_div << SPI_SSPCR0_SCR_LSB);
        spi_regs->cr0 = temp;
        return true;
      }

      __attribute__ ((always_inline)) inline void lgfx_spi_set_format(volatile spi_hw_t * spi_regs, uint data_bits, spi_cpol_t cpol, spi_cpha_t cpha, [[maybe_unused]]spi_order_t order)
      {
        uint32_t temp = spi_regs->cr0;
        temp &= ~(SPI_SSPCR0_DSS_BITS | SPI_SSPCR0_SPO_BITS | SPI_SSPCR0_SPH_BITS);
        temp |= (data_bits - 1) << SPI_SSPCR0_DSS_LSB |
          cpol << SPI_SSPCR0_SPO_LSB |
          cpha << SPI_SSPCR0_SPH_LSB;
        spi_regs->cr0 = temp;
      }

      bool lgfx_spi_set_pin_function(int mosi, int miso, int sclk)
      {
        if ((mosi != -1) && (!lgfx_gpio_set_function(mosi, GPIO_FUNC_SPI))) { return false; }
        if ((sclk != -1) && (!lgfx_gpio_set_function(sclk, GPIO_FUNC_SPI))) { return false; }
        if ((miso != -1) && (!lgfx_gpio_set_function(miso, GPIO_FUNC_SPI))) { return false; }
        return true;
      }

      bool lgfx_spi_init(volatile spi_hw_t * spi_regs)
      {
        lgfx_spi_reset(spi_regs);
        lgfx_spi_unreset(spi_regs);
        // SPIのクロック周波数を設定
        if (!lgfx_spi_set_baudrate(spi_regs, 1000000))
        {
          return false;
        }
        lgfx_spi_set_format(spi_regs, 8, SPI_CPOL_0, SPI_CPHA_0, SPI_MSB_FIRST);

        spi_regs->dmacr |= (SPI_SSPDMACR_TXDMAE_BITS | SPI_SSPDMACR_RXDMAE_BITS);
        // SPI有効化
        spi_regs->cr1 |= SPI_SSPCR1_SSE_BITS;
        DBGPRINT("cr1 %08x\n", spi_regs->cr1);
        return true;
      }

      void lgfx_spi_deinit(volatile spi_hw_t * spi_regs)
      {
        spi_regs->cr1 &= ~SPI_SSPCR1_SSE_BITS;
        spi_regs->dmacr &= ~(SPI_SSPDMACR_TXDMAE_BITS | SPI_SSPDMACR_RXDMAE_BITS);
        lgfx_spi_reset(spi_regs);
      }
    }

    static std::pair<cpp::result<void, error_t>, bool> check_pin_update(int current_pin, int new_pin)
    {
      bool need_update = false;
      cpp::result<void, error_t> result = {};
      if (new_pin != -1)
      {
        if (current_pin == -1)
        {
          need_update = true;
        }
        else if (current_pin != new_pin)
        {
          result = cpp::fail(error_t::invalid_arg);
        }
      }
      return { result, need_update };
    }

//----------------------------------------------------------------------------

    cpp::result<void, error_t> init(int spi_port, int pin_sclk, int pin_miso, int pin_mosi)
    {
      DBGPRINT("enter %s\n", __func__);
      if (spi_port < 0 || spi_port >= n_spi)
      {
        return cpp::fail(error_t::invalid_arg);
      }
      // DBGPRINT("ref_count %d\n", spi_info[spi_port].ref_count);
      if (spi_info[spi_port].ref_count == 0)
      {
        const spi_pinlist_str pinlist = spi_pinlist[spi_port];
        if (!lgfx::v1::rp2040::pin_check(pin_sclk, pinlist.sclk_pinlist))
        {
          return cpp::fail(error_t::invalid_arg);
        }
        // pin_misoは未使用(-1)でもOKとする
        if (pin_miso != -1 && !lgfx::v1::rp2040::pin_check(pin_miso, pinlist.miso_pinlist))
        {
          return cpp::fail(error_t::invalid_arg);
        }
        // pin_mosiは未使用(-1)でもOKとする
        if (pin_mosi != -1 && !lgfx::v1::rp2040::pin_check(pin_mosi, pinlist.mosi_pinlist))
        {
          return cpp::fail(error_t::invalid_arg);
        }
        lgfx_spi_set_pin_function(pin_mosi, pin_miso, pin_sclk);
        spi_info[spi_port].pin_sclk = pin_sclk;
        spi_info[spi_port].pin_miso = pin_miso;
        spi_info[spi_port].pin_mosi = pin_mosi;
        if (!lgfx_spi_init(spi_dev[spi_port]))
        {
          return cpp::fail(error_t::invalid_arg);
        }
        spi_info[spi_port].ref_count = 1;
        DBGPRINT("return %s\n", __func__);
        return {};
      }
      //
      if (spi_info[spi_port].pin_sclk != pin_sclk)
      {
        return cpp::fail(error_t::invalid_arg);
      }
      //
      auto rc = check_pin_update(spi_info[spi_port].pin_miso, pin_miso);
      auto result_miso = rc.first;
      auto need_update_miso = rc.second;
      if (result_miso.has_error())
      {
        return result_miso;
      }
      if (need_update_miso)
      {
        spi_info[spi_port].pin_miso = pin_miso;
      }
      //
      rc = check_pin_update(spi_info[spi_port].pin_mosi, pin_mosi);
      auto result_mosi = rc.first;
      auto need_update_mosi = rc.second;
      if (result_mosi.has_error())
      {
        return result_mosi;
      }
      if (need_update_mosi)
      {
        spi_info[spi_port].pin_mosi = pin_mosi;
      }
      if (need_update_miso || need_update_mosi)
      {
        lgfx_spi_set_pin_function(spi_info[spi_port].pin_mosi,
          spi_info[spi_port].pin_miso, spi_info[spi_port].pin_sclk);
      }
      spi_info[spi_port].ref_count++;
      DBGPRINT("return %s\n", __func__);
      return {};
    }

    void release(int spi_port)
    {
      if (spi_info[spi_port].ref_count == 0)
      {
        return;
      }
      spi_info[spi_port].ref_count--;
      if (spi_info[spi_port].ref_count == 0)
      {
        spi_info[spi_port].pin_sclk = -1;
        spi_info[spi_port].pin_miso = -1;
        spi_info[spi_port].pin_mosi = -1;
        lgfx_spi_deinit(spi_dev[spi_port]);
      }
    }

    bool lgfx_spi_set_frequency(int spi_port, uint32_t baudrate)
    {
      return lgfx_spi_set_baudrate(spi_dev[spi_port], baudrate);
    }


    void beginTransaction(int spi_port, uint32_t freq, int spi_mode)
    {
      static constexpr spi_cpha_t cpha_table[] = { SPI_CPHA_0, SPI_CPHA_1, SPI_CPHA_0, SPI_CPHA_1 };
      static constexpr spi_cpol_t cpol_table[] = { SPI_CPOL_0, SPI_CPOL_0, SPI_CPOL_1, SPI_CPOL_1 };
      if (spi_mode < 0 || spi_mode > 3)
      {
        spi_mode = 0;
      }
      lgfx_spi_set_format(spi_dev[spi_port], 8, cpol_table[spi_mode], cpha_table[spi_mode], SPI_MSB_FIRST);
      lgfx_spi_set_baudrate(spi_dev[spi_port], freq);
    }

    void endTransaction([[maybe_unused]]int spi_port)
    {

    }


    bool is_rx_fifo_not_empty(int spi_port)
    {
      return ((spi_dev[spi_port]->sr & SPI_SSPSR_RNE_BITS)  != 0);
    }

    bool is_tx_fifo_not_full(int spi_port)
    {
      return ((spi_dev[spi_port]->sr & SPI_SSPSR_TNF_BITS)  != 0);
    }

    void clear_rx_fifo(int spi_port)
    {
      // FIFO内のデータをすべて読みだす
      while (is_rx_fifo_not_empty(spi_port))
      {
        static_cast<void>(spi_dev[spi_port]->dr);
      }
    }

    // FIFOを8bitモードにする。
    void set_dss_8(int spi_port)
    {
      //spi_dev[spi_port]-> cr0 BIt7 mask This was the correct way to set it to 16bit to 8-bit mode. 16bit to 8Bitモードへの設定方法です
      //Spi_stk = spi_dev[spi_port]->cr0;
      uint32_t _sspcr0_mask_8bit = spi_dev[spi_port]-> cr0;
      _sspcr0_mask_8bit &= ~0x0000000f;
      _sspcr0_mask_8bit |=  0x0000007;
      spi_dev[spi_port]->cr0 = _sspcr0_mask_8bit;
    }


    void readBytes(int spi_port, uint8_t* dst, size_t length)
    {
      uint8_t *p;
      p = dst;
      clear_rx_fifo (spi_port);
      set_dss_8 (spi_port);
      auto tx_length = length;
      do
      {
        DBGPRINT("tx_length %d : length %d\n", tx_length, length);
        while (tx_length && is_tx_fifo_not_full(spi_port))
        {
          // データを送信（中身は何でもよい訳ではない！ Send data (not just anything goes！）
          //Touch_XPT2046.cppで設定された制御コードをSPIの送信データに乗せないと、XPT2046は動作しません
          //If the control code set in Touch_XPT2046.cpp is not included in the SPI transmission data, the XPT2046 will not work.
          spi_dev[spi_port]->dr = *p++; //!!
          --tx_length;
        }
        // 制御コードが記載された *dst を上書きしないよう比較保護して受信バッファと兼用する
        // *dst, which contains the control code, is protected from being overwritten and is used as a receive buffer.
        while ((length > tx_length) && is_tx_fifo_not_full (spi_port))
        {
          *dst++ = spi_dev[spi_port]->dr;
          --length;
        }
      } while (length);
    }
  }

//----------------------------------------------------------------------------

  namespace i2c
  {
    namespace
    {
      // constant
      constexpr uint32_t i2c_timeout = 10;
      constexpr uint64_t i2c_1Hz_period_ns{1000ULL * 1000ULL * 1000ULL};

      enum class restart_state_t {
        none,
        restart,
      };
      enum class stop_state_t {
        none,
        stop,
      };
      enum class need_wait_t {
        none,
        wait,
      };

      struct i2c_info_str {
        uint32_t ref_count{0};
        int pin_sda{-1};
        int pin_scl{-1};
        uint32_t timeout_count; // 送受信時のタイムアウト検出用
        uint8_t last_byte;    // 未送信のデータ
        bool last_byte_valid{ false }; // 未送信のデータが有効ならfalse
        restart_state_t restart{ restart_state_t::none };
      };

      volatile i2c_hw_t *const i2c_dev[] = {
        reinterpret_cast<volatile i2c_hw_t *>(I2C0_BASE),
        reinterpret_cast<volatile i2c_hw_t *>(I2C1_BASE),
      };
      constexpr int n_i2c = std::extent<decltype(i2c_dev), 0>::value;

#if defined(PICO_RP2350)
      // RP2350 Dataheetの 9.4. Function Select (Table 642)を参照
      // ※30以降は2350Bで使用可能
      constexpr uint8_t i2c0_sda_pinlist[] = {  0,  4,  8, 12, 16, 20, 24, 28,     32, 36, 40, 44, UINT8_MAX };
      constexpr uint8_t i2c0_sck_pinlist[] = {  1,  5,  9, 13, 17, 21, 25, 29,     33, 37, 41, 45, UINT8_MAX };
      constexpr uint8_t i2c1_sda_pinlist[] = {  2,  6, 10, 14, 18, 22, 26,     30, 34, 38, 42, 46, UINT8_MAX };
      constexpr uint8_t i2c1_sck_pinlist[] = {  3,  7, 11, 15, 19, 23, 27,     31, 35, 39, 43, 47, UINT8_MAX };
#else
      // RP2040 Dataheetの 1.4.3. GPIO Functions Table 2を参照
      constexpr uint8_t i2c0_sda_pinlist[] = {  0,  4,  8, 12, 16, 20, 24, 28, UINT8_MAX };
      constexpr uint8_t i2c0_sck_pinlist[] = {  1,  5,  9, 13, 17, 21, 25, 29, UINT8_MAX };
      constexpr uint8_t i2c1_sda_pinlist[] = {  2,  6, 10, 14, 18, 22, 26,     UINT8_MAX };
      constexpr uint8_t i2c1_sck_pinlist[] = {  3,  7, 11, 15, 19, 23, 27,     UINT8_MAX };
#endif

      constexpr struct i2c_pinlist_str {
        const uint8_t *sda_pinlist;
        const uint8_t *scl_pinlist;
      } i2c_pinlist[] = {
        {
          .sda_pinlist = i2c0_sda_pinlist,
          .scl_pinlist = i2c0_sck_pinlist,
        },
        {
          .sda_pinlist = i2c1_sda_pinlist,
          .scl_pinlist = i2c1_sck_pinlist,
        },
      };

      i2c_info_str i2c_info[n_i2c];
      std::unordered_map<uint32_t, std::array<uint32_t, 4>> prescale_map;

      __attribute__((always_inline)) inline void lgfx_i2c_reset(volatile i2c_hw_t *i2c_regs)
      {
        lgfx_reset_block(i2c_regs == i2c_dev[0] ? RESETS_RESET_I2C0_BITS : RESETS_RESET_I2C1_BITS);
      }

      __attribute__((always_inline)) inline void lgfx_i2c_unreset(volatile i2c_hw_t *i2c_regs)
      {
        lgfx_unreset_block_wait(i2c_regs == i2c_dev[0] ? RESETS_RESET_I2C0_BITS : RESETS_RESET_I2C1_BITS);
      }

      __attribute__((always_inline)) inline void lgfx_i2c_enable(volatile i2c_hw_t *i2c_regs)
      {
        i2c_regs->enable = I2C_IC_ENABLE_ENABLE_VALUE_ENABLED;
      }

      __attribute__((always_inline)) inline void lgfx_i2c_disable(volatile i2c_hw_t *i2c_regs)
      {
        i2c_regs->enable = I2C_IC_ENABLE_ENABLE_VALUE_DISABLED;
      }

      __attribute__((always_inline)) inline void set_target_address(volatile i2c_hw_t *const i2c_regs, int addr)
      {
        lgfx_i2c_disable(i2c_regs);
        i2c_regs->tar = addr & I2C_IC_TAR_IC_TAR_BITS;
        lgfx_i2c_enable(i2c_regs);
      }

      __attribute__((always_inline)) inline void send_data(volatile i2c_hw_t *const i2c_regs, uint8_t data, restart_state_t restart, stop_state_t stop)
      {
        i2c_regs->data_cmd = ((restart == restart_state_t::restart) ? I2C_IC_DATA_CMD_RESTART_BITS : 0x0) |
                             ((stop == stop_state_t::stop) ? I2C_IC_DATA_CMD_STOP_BITS : 0x0) |
                             static_cast<uint32_t>(data);
      }

      __attribute__((always_inline)) inline void prepare_recv(volatile i2c_hw_t *const i2c_regs, bool restart, bool stop)
      {
        i2c_regs->data_cmd = (restart ? I2C_IC_DATA_CMD_RESTART_BITS : 0x0) |
                              (stop ? I2C_IC_DATA_CMD_STOP_BITS : 0x0) |
                              I2C_IC_DATA_CMD_CMD_BITS | 0xaa;
      }

      __attribute__((always_inline)) inline uint8_t recv_data(volatile i2c_hw_t *const i2c_regs)
      {
        return static_cast<uint8_t>(i2c_regs->data_cmd);
      }

      __attribute__((always_inline)) inline bool is_rx_fifo_not_empty(volatile i2c_hw_t *const i2c_regs)
      {
        return ((i2c_regs->status & I2C_IC_STATUS_RFNE_BITS) != 0);
      }

      __attribute__((always_inline)) inline bool is_rx_fifo_empty(volatile i2c_hw_t *const i2c_regs)
      {
        return ((i2c_regs->status & I2C_IC_STATUS_RFNE_BITS) == 0);
      }

      __attribute__((always_inline)) inline bool is_tx_fifo_full(volatile i2c_hw_t *const i2c_regs)
      {
        return ((i2c_regs->status & I2C_IC_STATUS_TFNF_BITS) == 0);
      }

      __attribute__((always_inline)) inline bool is_tx_fifo_not_full(volatile i2c_hw_t *const i2c_regs)
      {
        return ((i2c_regs->status & I2C_IC_STATUS_TFNF_BITS) != 0);
      }

      __attribute__((always_inline)) inline bool is_tx_fifo_empty(volatile i2c_hw_t *const i2c_regs)
      {
        return ((i2c_regs->status & I2C_IC_STATUS_TFE_BITS) != 0);
      }

      static __attribute__((always_inline)) inline bool is_tx_fifo_not_empty(volatile i2c_hw_t *const i2c_regs)
      {
        return ((i2c_regs->status & I2C_IC_STATUS_TFE_BITS) == 0);
      }
      __attribute__((always_inline)) inline bool is_tx_not_complete(volatile i2c_hw_t *const i2c_regs)
      {
        return ((i2c_regs->raw_intr_stat & I2C_IC_RAW_INTR_STAT_TX_EMPTY_BITS) == 0);
      }

      __attribute__((always_inline)) inline void abort_transfer(volatile i2c_hw_t *const i2c_regs)
      {
        i2c_regs->enable = I2C_IC_ENABLE_ENABLE_BITS | I2C_IC_ENABLE_ABORT_BITS;
      }

      __attribute__((always_inline)) inline bool is_abort_complete(volatile i2c_hw_t *const i2c_regs)
      {
        return ((i2c_regs->enable & I2C_IC_ENABLE_ABORT_BITS) == 0);
      }

      __attribute__((always_inline)) inline uint32_t get_tx_fifo_cnt(volatile i2c_hw_t *const i2c_regs) {
          return i2c_regs->txflr;
      }

      __attribute__((always_inline)) inline uint32_t get_write_available(volatile i2c_hw_t *const i2c_regs) {
        static constexpr  uint32_t IC_TX_BUFFER_DEPTH = 16;
        return IC_TX_BUFFER_DEPTH - get_tx_fifo_cnt(i2c_regs);
      }

      __attribute__((always_inline)) inline uint32_t get_read_available(volatile i2c_hw_t *const i2c_regs) {
        return i2c_regs->rxflr;
      }

      __attribute__((always_inline)) inline bool wait_for_txfifo_not_full(int i2c_port)
      {
        volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
        bool rc = true;
        uint32_t wait_count = i2c_info[i2c_port].timeout_count;
        uint32_t i = 0;
        while (is_tx_fifo_full(i2c_regs)) {
          i++;
          if (i > wait_count) {
            rc = false;
            break;
          }
        }
        return rc;
      }

      __attribute__((always_inline)) inline bool wait_for_txfifo_empty(int i2c_port)
      {
        volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
        bool rc = true;
        uint32_t wait_count = i2c_info[i2c_port].timeout_count * (get_tx_fifo_cnt(i2c_regs) + 1);
        uint32_t i = 0;
        while (is_tx_not_complete(i2c_regs)) {
          i++;
          if (i > wait_count) {
            rc = false;
            break;
          }
        }
        return rc;
      }

      __attribute__((always_inline)) inline bool wait_for_tx_complete(int i2c_port)
      {
        volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
        bool rc = true;
        uint32_t wait_count = i2c_info[i2c_port].timeout_count * (get_tx_fifo_cnt(i2c_regs) + 1);
        uint32_t i = 0;
        while (is_tx_fifo_not_empty(i2c_regs)) { // TODO:
          i++;
          if (i > wait_count) {
            rc = false;
            break;
          }
        }
        return rc;
      }

      __attribute__((always_inline)) inline bool wait_for_rxfifo_not_empty(int i2c_port)
      {
        volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
        bool rc = true;
        uint32_t wait_count = i2c_info[i2c_port].timeout_count;
        uint32_t i = 0;
        while (is_rx_fifo_empty(i2c_regs)) {
          i++;
          if (i > wait_count) {
            rc = false;
            DBGPRINT("i = %d\n", i);
            break;
          }
        }
        return rc;
      }

      __attribute__((always_inline)) inline void set_last_byte(int i2c_port, uint8_t last_byte)
      {
        auto info = &i2c_info[i2c_port];
        info->last_byte = last_byte;
        info->last_byte_valid = true;
      }

      bool send_byte_blocking(int i2c_port, uint8_t byte, stop_state_t stop)
      {
        volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
        auto info = &i2c_info[i2c_port];
        bool rc = wait_for_txfifo_not_full(i2c_port);
        if (!rc) {
          return false;
        }
        send_data(i2c_regs, byte, info->restart, stop);
        return true;
      }

      bool send_last_byte(int i2c_port, stop_state_t stop, need_wait_t need_wait)
      {
        auto info = &i2c_info[i2c_port];
        if (!info->last_byte_valid) {
          return true;
        }
        bool rc = send_byte_blocking(i2c_port, info->last_byte, stop);
        if (!rc) {
          DBGPRINT("send_byte_blocking() failed\n");
          return false;
        }
        info->last_byte_valid = false;
        if (need_wait == need_wait_t::none) {
          return true;
          }
        rc = wait_for_tx_complete(i2c_port);
        return rc;
      }

      constexpr uint32_t calc_scl_factor(uint32_t period, uint32_t scl_low, uint32_t scl_high)
      {
        return ((period + scl_low - scl_high) / 2);
      }

      constexpr uint32_t nstoclk(uint32_t time_ns, uint32_t clk_freq)
      {
        if (time_ns == 0)
        {
          return 0;
        }
        constexpr uint32_t MHz{1000 * 1000};
        uint32_t clk_freq_MHz = (clk_freq + MHz - 1) / MHz;
        return (((time_ns * clk_freq_MHz) + 1000 - 1) / 1000);
      }

      bool lgfx_i2c_set_baudrate(volatile i2c_hw_t *i2c_regs, uint32_t baudrate)
        {
          uint32_t hcnt;
          uint32_t lcnt;
          uint32_t sda_tx_setup_count;
          uint32_t sda_tx_hold_count;
          enum
          {
            i2c_standard_mode = 0,
            i2c_fast_mode = 1,
            i2c_fast_mode_plus = 2
          } i2c_speed;

          static constexpr uint32_t i2c_standard_mode_freq{100 * 1000};
          static constexpr uint32_t i2c_standard_mode_min_scl_high_time_ns{4000};
          static constexpr uint32_t i2c_standard_mode_min_scl_low_time_ns{4700};
          static constexpr uint32_t i2c_standard_mode_min_data_setup_time_ns{250};
          static constexpr uint32_t i2c_standard_mode_min_data_hold_time_ns{300};
          static constexpr uint32_t i2c_standard_mode_period_ns{i2c_1Hz_period_ns / (static_cast<uint64_t>(i2c_standard_mode_freq))};

          static constexpr uint32_t i2c_fast_mode_freq{400 * 1000};
          static constexpr uint32_t i2c_fast_mode_min_scl_high_time_ns{600};
          static constexpr uint32_t i2c_fast_mode_min_scl_low_time_ns{1300};
          static constexpr uint32_t i2c_fast_mode_min_data_setup_time_ns{100};
          static constexpr uint32_t i2c_fast_mode_min_data_hold_time_ns{300};
          static constexpr uint32_t i2c_fast_mode_period_ns{i2c_1Hz_period_ns / (static_cast<uint64_t>(i2c_fast_mode_freq))};

          static constexpr uint32_t i2c_fast_mode_plus_freq{1000 * 1000};
          static constexpr uint32_t i2c_fast_mode_plus_min_scl_high_time_ns{260};
          static constexpr uint32_t i2c_fast_mode_plus_min_scl_low_time_ns{500};
          static constexpr uint32_t i2c_fast_plus_mode_min_data_setup_time_ns{50};
          static constexpr uint32_t i2c_fast_mode_plus_min_data_hold_time_ns{0};
          static constexpr uint32_t i2c_fast_mode_plus_period_ns{i2c_1Hz_period_ns / (static_cast<uint64_t>(i2c_fast_mode_plus_freq))};

          static constexpr uint32_t i2c_scl_factor_table[] = {
              calc_scl_factor(i2c_standard_mode_period_ns, i2c_standard_mode_min_scl_low_time_ns, i2c_standard_mode_min_scl_high_time_ns),
              calc_scl_factor(i2c_fast_mode_period_ns, i2c_fast_mode_min_scl_low_time_ns, i2c_fast_mode_min_scl_high_time_ns),
              calc_scl_factor(i2c_fast_mode_plus_period_ns, i2c_fast_mode_plus_min_scl_low_time_ns, i2c_fast_mode_plus_min_scl_high_time_ns),
          };
          static constexpr uint32_t i2c_period_table[] = {
              i2c_standard_mode_period_ns,
              i2c_fast_mode_period_ns,
              i2c_fast_mode_plus_period_ns,
          };
          static constexpr uint32_t i2c_data_setup_time_table[] = {
              i2c_standard_mode_min_data_setup_time_ns,
              i2c_fast_mode_min_data_setup_time_ns,
              i2c_fast_plus_mode_min_data_setup_time_ns,
          };
          static constexpr uint32_t i2c_data_hold_time_table[] = {
              i2c_standard_mode_min_data_hold_time_ns,
              i2c_fast_mode_min_data_hold_time_ns,
              i2c_fast_mode_plus_min_data_hold_time_ns,
          };

          // DBGPRINT("%s baud = %u\n", __func__, baudrate);
          if (baudrate <= i2c_standard_mode_freq)
          {
            i2c_speed = i2c_standard_mode;
          }
          else if (baudrate <= i2c_fast_mode_freq)
          {
            i2c_speed = i2c_fast_mode;
          }
          else
          {
            i2c_speed = i2c_fast_mode_plus;
          }
          auto val = prescale_map.find(baudrate);
          if (val != prescale_map.end())
          {
            hcnt = val->second[0];
            lcnt = val->second[1];
            sda_tx_setup_count = val->second[2];
            sda_tx_hold_count = val->second[3];
          }
          else
          {
            if (baudrate == 0)
            {
              DBGPRINT("%s return\n", __func__);
              return false;
            }
#ifdef UNITTEST
            uint32_t freq_in = sys_clock_hz;
#else
            uint32_t freq_in = clock_get_hz(clk_sys);
#endif
            uint32_t period = (freq_in + baudrate / 2) / baudrate;
            lcnt = (period * i2c_scl_factor_table[i2c_speed]) / i2c_period_table[i2c_speed];
            hcnt = period - lcnt;
            if (hcnt > I2C_IC_FS_SCL_HCNT_IC_FS_SCL_HCNT_BITS)
            {
              DBGPRINT("%s return hcnt = %u\n", __func__, hcnt);
              return false;
            }
            if (lcnt > I2C_IC_FS_SCL_LCNT_IC_FS_SCL_LCNT_BITS)
            {
              DBGPRINT("%s return lcnt = %u\n", __func__, lcnt);
              return false;
            }
            // IC_SS_SCL_HCNT and IC_FS_SCL_HCNT register values must be larger than IC_FS_SPKLEN + 5.
            if (hcnt <= 6)
            {
              DBGPRINT("%s return hcnt = %u\n", __func__, hcnt);
              return false;
            }
            // IC_SS_SCL_LCNT and IC_FS_SCL_LCNT register values must be larger than IC_FS_SPKLEN + 7.
            if (lcnt <= 8)
            {
              DBGPRINT("%s return\n", __func__);
              return false;
            }

            sda_tx_setup_count = nstoclk(i2c_data_setup_time_table[i2c_speed], freq_in);
            sda_tx_hold_count = nstoclk(i2c_data_hold_time_table[i2c_speed], freq_in);

            if (sda_tx_hold_count >= lcnt - 2)
            {
              DBGPRINT("%s return %d %d\n", __func__, sda_tx_hold_count, lcnt);
              return false;
            }
            prescale_map.emplace(baudrate, decltype(prescale_map)::mapped_type{hcnt, lcnt, sda_tx_setup_count, sda_tx_hold_count});
          }
#ifndef UNITTEST
          lgfx_i2c_disable(i2c_regs);

          uint32_t speed_param;
          if (i2c_speed == i2c_standard_mode)
          {
            speed_param = (I2C_IC_CON_SPEED_VALUE_STANDARD << I2C_IC_CON_SPEED_LSB);
          }
          else if (i2c_speed == i2c_fast_mode)
          {
            speed_param = (I2C_IC_CON_SPEED_VALUE_FAST << I2C_IC_CON_SPEED_LSB);
          }
          else
          {
            speed_param = (I2C_IC_CON_SPEED_VALUE_HIGH << I2C_IC_CON_SPEED_LSB);
          }
          uint32_t temp = i2c_regs->con;
          temp &= ~(I2C_IC_CON_SPEED_BITS);
          temp |= speed_param;
          i2c_regs->con = temp;
          if (i2c_speed == i2c_standard_mode)
          {
            i2c_regs->ss_scl_hcnt = hcnt;
            i2c_regs->ss_scl_lcnt = lcnt;
          }
          else
          {
            i2c_regs->fs_scl_hcnt = hcnt;
            i2c_regs->fs_scl_lcnt = lcnt;
          }
          i2c_regs->fs_spklen = (lcnt < 16) ? 1 : lcnt / 16;
          temp = i2c_regs->sda_hold;
          temp &= ~(I2C_IC_SDA_HOLD_IC_SDA_TX_HOLD_BITS);
          temp |= (sda_tx_hold_count << I2C_IC_SDA_HOLD_IC_SDA_TX_HOLD_LSB);
          i2c_regs->sda_hold = temp;
          lgfx_i2c_enable(i2c_regs);
#endif
          return true;
        }

      void lgfx_i2c_init(volatile i2c_hw_t * i2c_regs)
      {
        lgfx_i2c_reset(i2c_regs);
        lgfx_i2c_unreset(i2c_regs);

        i2c_regs->enable = I2C_IC_ENABLE_ENABLE_VALUE_DISABLED;

        i2c_regs->con =
          I2C_IC_CON_SPEED_VALUE_FAST << I2C_IC_CON_SPEED_LSB |
          I2C_IC_CON_MASTER_MODE_BITS |
          I2C_IC_CON_IC_SLAVE_DISABLE_BITS |
          I2C_IC_CON_IC_RESTART_EN_BITS |
          I2C_IC_CON_TX_EMPTY_CTRL_BITS;

        i2c_regs->tx_tl = 0;
        i2c_regs->rx_tl = 0;
        i2c_regs->dma_cr = I2C_IC_DMA_CR_TDMAE_BITS | I2C_IC_DMA_CR_RDMAE_BITS;
      }

      void lgfx_i2c_deinit(volatile i2c_hw_t * i2c_regs)
      {
        i2c_regs->enable = I2C_IC_ENABLE_ENABLE_VALUE_DISABLED;
        lgfx_i2c_reset(i2c_regs);
      }
    }

    cpp::result<void, error_t> init(int i2c_port, int pin_sda, int pin_scl)
    {
      volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
      auto info = &i2c_info[i2c_port];
      if (i2c_port < 0 || i2c_port >= n_i2c)
      {
        DBGPRINT("invalid port number %d\n", i2c_port);
        return cpp::fail(error_t::invalid_arg);
      }
      if (info->ref_count == 0)
      {
        const struct i2c_pinlist_str pinlist = i2c_pinlist[i2c_port];
        if (!lgfx::v1::rp2040::pin_check(pin_sda, pinlist.sda_pinlist))
        {
          DBGPRINT("invalid sda %d\n", pin_sda);
          return cpp::fail(error_t::invalid_arg);
        }
        if (!lgfx::v1::rp2040::pin_check(pin_scl, pinlist.scl_pinlist))
        {
          DBGPRINT("invalid scl %d\n", pin_scl);
          return cpp::fail(error_t::invalid_arg);
        }
        lgfx_gpio_set_function(pin_sda, GPIO_FUNC_I2C);
        lgfx_gpio_set_function(pin_scl, GPIO_FUNC_I2C);
        lgfx_i2c_init(i2c_regs);
        info->pin_sda = pin_sda;
        info->pin_scl = pin_scl;
        info->ref_count = 1;
        return {};
      }
      if (i2c_info[i2c_port].pin_sda != pin_sda)
      {
        return cpp::fail(error_t::invalid_arg);
      }
      if (info->pin_scl != pin_scl)
      {
        return cpp::fail(error_t::invalid_arg);
      }
      info->ref_count++;
      return {};
    }

    cpp::result<void, error_t> release(int i2c_port)
    {
      volatile i2c_hw_t * const i2c_regs = i2c_dev[i2c_port];
      auto info = &i2c_info[i2c_port];

      if (info->ref_count == 0)
      {
        return {};
      }
      info->ref_count--;
      if (info->ref_count == 0)
      {
        info->pin_sda = -1;
        info->pin_scl = -1;
        lgfx_i2c_deinit(i2c_regs);
      }
      return {};
    }

    cpp::result<void, error_t> restart(int i2c_port, int i2c_addr, uint32_t freq, [[maybe_unused]] bool read)
    {
      volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
      DBG_ENTER();
      // readで読み出しが行われない可能性があるので、stop conditionに遷移する
      if (!send_last_byte(i2c_port, stop_state_t::stop , need_wait_t::wait)) {
        return cpp::fail(error_t::connection_lost);
      }
      if (!lgfx_i2c_set_baudrate(i2c_regs, freq)) {
        return cpp::fail(error_t::connection_lost);
      }
      set_target_address(i2c_regs, i2c_addr);
      return {};
    }

    cpp::result<void, error_t> beginTransaction(int i2c_port, int i2c_addr, uint32_t freq, [[maybe_unused]] bool read)
    {
      volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
      auto info = &i2c_info[i2c_port];
      DBG_ENTER();
      if (!lgfx_i2c_set_baudrate(i2c_regs, freq)) {
        return cpp::fail(error_t::connection_lost);
      }
      set_target_address(i2c_regs, i2c_addr);
      uint32_t clk_per_ms = clock_get_hz(clk_sys) / 1000;
      info->timeout_count = clk_per_ms * i2c_timeout;;
      info->last_byte_valid = false;
      info->restart = restart_state_t::none;
      return {};
    }

    cpp::result<void, error_t> endTransaction(int i2c_port)
    {
      DBG_ENTER();
      // 未送信の最終データをstop conditionで送信
      if (!send_last_byte(i2c_port, stop_state_t::stop, need_wait_t::wait)) {
        return cpp::fail(error_t::connection_lost);
      }
      return {};
    }

    cpp::result<void, error_t> writeBytes(int i2c_port, const uint8_t *data, size_t length)
    {
      DBGPRINTFUNC("%d\n", length);
      if (length == 0) {
        return {};
      }
      if (!send_last_byte(i2c_port, stop_state_t::none, need_wait_t::none)) {
        DBGPRINTFUNC("send_last_byte() failed\n");
        return cpp::fail(error_t::connection_lost);
      }
      auto last_data_index = length - 1;
      for (decltype(length) i = 0; i < last_data_index; i++) {
        bool rc = send_byte_blocking(i2c_port, *data++, stop_state_t::none);
        if (!rc) {
          DBGPRINTFUNC("send_byte_blocking() failed\n");
          return cpp::fail(error_t::connection_lost);
        }
      }
      set_last_byte(i2c_port, *data);
      put_dump_byte(data, 0, length);
      return {};
    }

    cpp::result<void, error_t> readBytes(int i2c_port, uint8_t *data, size_t length, bool last_nack = false)
    {
      volatile i2c_hw_t *const i2c_regs = i2c_dev[i2c_port];
      auto info = &i2c_info[i2c_port];
      if (length == 0) {
        return {};
      }
      for (decltype(length) i = 0; i < length; i++) {
        prepare_recv(i2c_regs, (i == 0) && info->restart == restart_state_t::restart, (i == length - 1));
        bool rc = wait_for_rxfifo_not_empty(i2c_port);
        if (!rc) {
          DBGPRINTFUNC("timeout %04x %02x %d\n", i2c_regs->status, i2c_regs->rxflr, is_rx_fifo_not_empty(i2c_regs));
          return cpp::fail(error_t::connection_lost);
        }
        *data++ = recv_data(i2c_regs);
      }
      info->restart = restart_state_t::none;
      DBGPRINTFUNC("%d\n", length);
      put_dump_byte(data, 0, length);
      return {};
    }

    //--------

    cpp::result<void, error_t> transactionWrite(int i2c_port, int addr, const uint8_t *writedata, uint8_t writelen, uint32_t freq)
    {
      cpp::result<void, error_t> res;
      if ((res = beginTransaction(i2c_port, addr, freq, false)).has_value() && (res = writeBytes(i2c_port, writedata, writelen)).has_value())
      {
        res = endTransaction(i2c_port);
      }
      return res;
    }

    cpp::result<void, error_t> transactionRead(int i2c_port, int addr, uint8_t *readdata, uint8_t readlen, uint32_t freq)
    {
      cpp::result<void, error_t> res;
      if ((res = beginTransaction(i2c_port, addr, freq, false)).has_value() && (res = readBytes(i2c_port, readdata, readlen)).has_value())
      {
        res = endTransaction(i2c_port);
      }
      return res;
    }

    cpp::result<void, error_t> transactionWriteRead(int i2c_port, int addr, const uint8_t *writedata, uint8_t writelen, uint8_t *readdata, size_t readlen, uint32_t freq)
    {
      cpp::result<void, error_t> res;
      if ((res = beginTransaction(i2c_port, addr, freq, false)).has_value() && (res = writeBytes(i2c_port, writedata, writelen)).has_value() && (res = restart(i2c_port, addr, freq, false)).has_value() && (res = readBytes(i2c_port, readdata, readlen)).has_value())
      {
        res = endTransaction(i2c_port);
      }
      return res;
    }

    cpp::result<uint8_t, error_t> readRegister8(int i2c_port, int addr, uint8_t reg, uint32_t freq)
    {
      auto res = transactionWriteRead(i2c_port, addr, &reg, 1, &reg, 1, freq);
      if (res.has_value())
      {
        return reg;
      }
      return cpp::fail(res.error());
    }

    cpp::result<void, error_t> writeRegister8(int i2c_port, int addr, uint8_t reg, uint8_t data, uint8_t mask, uint32_t freq)
    {
      uint8_t tmp[2] = {reg, data};
      if (mask != 0)
      {
        auto res = transactionWriteRead(i2c_port, addr, &reg, 1, &tmp[1], 1, freq);
        if (res.has_error())
        {
          return res;
        }
        tmp[1] = (tmp[1] & mask) | data;
      }
      return transactionWrite(i2c_port, addr, tmp, 2, freq);
    }
  }

//----------------------------------------------------------------------------
 }
}

#endif
