text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <stdio.h>
  #include <stdint.h>
  #include <string.h>
  
  #include "py/runtime.h"
  #include "timer.h"
  #include "dac.h"
  #include "dma.h"
  #include "pin.h"
  #include "genhdr/pins.h"
  
  /// \moduleref pyb
  /// \class DAC - digital to analog conversion
  ///
  /// The DAC is used to output analog values (a specific voltage) on pin X5 or pin X6.
  /// The voltage will be between 0 and 3.3V.
  ///
  /// *This module will undergo changes to the API.*
  ///
  /// Example usage:
  ///
  ///     from pyb import DAC
  ///
  ///     dac = DAC(1)            # create DAC 1 on pin X5
  ///     dac.write(128)          # write a value to the DAC (makes X5 1.65V)
  ///
  /// To output a continuous sine-wave:
  ///
  ///     import math
  ///     from pyb import DAC
  ///
  ///     # create a buffer containing a sine-wave
  ///     buf = bytearray(100)
  ///     for i in range(len(buf)):
  ///         buf[i] = 128 + int(127 * math.sin(2 * math.pi * i / len(buf)))
  ///
  ///     # output the sine-wave at 400Hz
  ///     dac = DAC(1)
  ///     dac.write_timed(buf, 400 * len(buf), mode=DAC.CIRCULAR)
  
  #if defined(MICROPY_HW_ENABLE_DAC) && MICROPY_HW_ENABLE_DAC
  
  STATIC DAC_HandleTypeDef DAC_Handle;
  
  void dac_init(void) {
      memset(&DAC_Handle, 0, sizeof DAC_Handle);
      DAC_Handle.Instance = DAC;
      DAC_Handle.State = HAL_DAC_STATE_RESET;
      HAL_DAC_Init(&DAC_Handle);
  }
  
  #if defined(TIM6)
  STATIC void TIM6_Config(uint freq) {
      // Init TIM6 at the required frequency (in Hz)
      TIM_HandleTypeDef *tim = timer_tim6_init(freq);
  
      // TIM6 TRGO selection
      TIM_MasterConfigTypeDef config;
      config.MasterOutputTrigger = TIM_TRGO_UPDATE;
      config.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
      HAL_TIMEx_MasterConfigSynchronization(tim, &config);
  
      // TIM6 start counter
      HAL_TIM_Base_Start(tim);
  }
  #endif
  
  STATIC uint32_t TIMx_Config(mp_obj_t timer) {
      // TRGO selection to trigger DAC
      TIM_HandleTypeDef *tim = pyb_timer_get_handle(timer);
      TIM_MasterConfigTypeDef config;
      config.MasterOutputTrigger = TIM_TRGO_UPDATE;
      config.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
      HAL_TIMEx_MasterConfigSynchronization(tim, &config);
  
      // work out the trigger channel (only certain ones are supported)
      if (tim->Instance == TIM2) {
          return DAC_TRIGGER_T2_TRGO;
      } else if (tim->Instance == TIM4) {
          return DAC_TRIGGER_T4_TRGO;
      } else if (tim->Instance == TIM5) {
          return DAC_TRIGGER_T5_TRGO;
      #if defined(TIM6)
      } else if (tim->Instance == TIM6) {
          return DAC_TRIGGER_T6_TRGO;
      #endif
      #if defined(TIM7)
      } else if (tim->Instance == TIM7) {
          return DAC_TRIGGER_T7_TRGO;
      #endif
      #if defined(TIM8)
      } else if (tim->Instance == TIM8) {
          return DAC_TRIGGER_T8_TRGO;
      #endif
      } else {
          nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Timer does not support DAC triggering"));
      }
  }
  
  /******************************************************************************/
  // MicroPython bindings
  
  typedef enum {
      DAC_STATE_RESET,
      DAC_STATE_WRITE_SINGLE,
      DAC_STATE_BUILTIN_WAVEFORM,
      DAC_STATE_DMA_WAVEFORM, // should be last enum since we use space beyond it
  } pyb_dac_state_t;
  
  typedef struct _pyb_dac_obj_t {
      mp_obj_base_t base;
      uint32_t dac_channel; // DAC_CHANNEL_1 or DAC_CHANNEL_2
      const dma_descr_t *tx_dma_descr;
      uint16_t pin; // GPIO_PIN_4 or GPIO_PIN_5
      uint8_t bits; // 8 or 12
      uint8_t state;
  } pyb_dac_obj_t;
  
  STATIC mp_obj_t pyb_dac_init_helper(pyb_dac_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_bits, MP_ARG_INT, {.u_int = 8} },
      };
  
      // parse args
      mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
      mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
  
      // GPIO configuration
      GPIO_InitTypeDef GPIO_InitStructure;
      GPIO_InitStructure.Pin = self->pin;
      GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
      GPIO_InitStructure.Pull = GPIO_NOPULL;
      HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);
  
      // DAC peripheral clock
      #if defined(MCU_SERIES_F4) || defined(MCU_SERIES_F7)
      __DAC_CLK_ENABLE();
      #elif defined(MCU_SERIES_L4)
      __HAL_RCC_DAC1_CLK_ENABLE();
      #else
      #error Unsupported Processor
      #endif
  
      // stop anything already going on
      __DMA1_CLK_ENABLE();
      DMA_HandleTypeDef DMA_Handle;
      /* Get currently configured dma */
      dma_init_handle(&DMA_Handle, self->tx_dma_descr, (void*)NULL);
      // Need to deinit DMA first
      DMA_Handle.State = HAL_DMA_STATE_READY;
      HAL_DMA_DeInit(&DMA_Handle);
  
      HAL_DAC_Stop(&DAC_Handle, self->dac_channel);
      if ((self->dac_channel == DAC_CHANNEL_1 && DAC_Handle.DMA_Handle1 != NULL)
              || (self->dac_channel == DAC_CHANNEL_2 && DAC_Handle.DMA_Handle2 != NULL)) {
          HAL_DAC_Stop_DMA(&DAC_Handle, self->dac_channel);
      }
  
      // set bit resolution
      if (args[0].u_int == 8 || args[0].u_int == 12) {
          self->bits = args[0].u_int;
      } else {
          mp_raise_ValueError("unsupported bits");
      }
  
      // reset state of DAC
      self->state = DAC_STATE_RESET;
  
      return mp_const_none;
  }
  
  // create the dac object
  // currently support either DAC1 on X5 (id = 1) or DAC2 on X6 (id = 2)
  
  /// \classmethod \constructor(port)
  /// Construct a new DAC object.
  ///
  /// `port` can be a pin object, or an integer (1 or 2).
  /// DAC(1) is on pin X5 and DAC(2) is on pin X6.
  STATIC mp_obj_t pyb_dac_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      // check arguments
      mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
  
      // get pin/channel to output on
      mp_int_t dac_id;
      if (MP_OBJ_IS_INT(args[0])) {
          dac_id = mp_obj_get_int(args[0]);
      } else {
          const pin_obj_t *pin = pin_find(args[0]);
          if (pin == &pin_A4) {
              dac_id = 1;
          } else if (pin == &pin_A5) {
              dac_id = 2;
          } else {
              nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Pin(%q) doesn't have DAC capabilities", pin->name));
          }
      }
  
      pyb_dac_obj_t *dac = m_new_obj(pyb_dac_obj_t);
      dac->base.type = &pyb_dac_type;
  
      if (dac_id == 1) {
          dac->pin = GPIO_PIN_4;
          dac->dac_channel = DAC_CHANNEL_1;
          dac->tx_dma_descr = &dma_DAC_1_TX;
      } else if (dac_id == 2) {
          dac->pin = GPIO_PIN_5;
          dac->dac_channel = DAC_CHANNEL_2;
          dac->tx_dma_descr = &dma_DAC_2_TX;
      } else {
          nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "DAC(%d) doesn't exist", dac_id));
      }
  
      // configure the peripheral
      mp_map_t kw_args;
      mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
      pyb_dac_init_helper(dac, n_args - 1, args + 1, &kw_args);
  
      // return object
      return dac;
  }
  
  STATIC mp_obj_t pyb_dac_init(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
      return pyb_dac_init_helper(args[0], n_args - 1, args + 1, kw_args);
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_dac_init_obj, 1, pyb_dac_init);
  
  /// \method deinit()
  /// Turn off the DAC, enable other use of pin.
  STATIC mp_obj_t pyb_dac_deinit(mp_obj_t self_in) {
      pyb_dac_obj_t *self = self_in;
      if (self->dac_channel == DAC_CHANNEL_1) {
          DAC_Handle.Instance->CR &= ~DAC_CR_EN1;
          DAC_Handle.Instance->CR |= DAC_CR_BOFF1;
      } else {
          DAC_Handle.Instance->CR &= ~DAC_CR_EN2;
          DAC_Handle.Instance->CR |= DAC_CR_BOFF2;
      }
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_dac_deinit_obj, pyb_dac_deinit);
  
  #if defined(TIM6)
  /// \method noise(freq)
  /// Generate a pseudo-random noise signal.  A new random sample is written
  /// to the DAC output at the given frequency.
  STATIC mp_obj_t pyb_dac_noise(mp_obj_t self_in, mp_obj_t freq) {
      pyb_dac_obj_t *self = self_in;
  
      // set TIM6 to trigger the DAC at the given frequency
      TIM6_Config(mp_obj_get_int(freq));
  
      if (self->state != DAC_STATE_BUILTIN_WAVEFORM) {
          // configure DAC to trigger via TIM6
          DAC_ChannelConfTypeDef config;
          config.DAC_Trigger = DAC_TRIGGER_T6_TRGO;
          config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
          HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
          self->state = DAC_STATE_BUILTIN_WAVEFORM;
      }
  
      // set noise wave generation
      HAL_DACEx_NoiseWaveGenerate(&DAC_Handle, self->dac_channel, DAC_LFSRUNMASK_BITS10_0);
      HAL_DAC_SetValue(&DAC_Handle, self->dac_channel, DAC_ALIGN_12B_L, 0x7ff0);
      HAL_DAC_Start(&DAC_Handle, self->dac_channel);
  
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_dac_noise_obj, pyb_dac_noise);
  #endif
  
  #if defined(TIM6)
  /// \method triangle(freq)
  /// Generate a triangle wave.  The value on the DAC output changes at
  /// the given frequency, and the frequence of the repeating triangle wave
  /// itself is 256 (or 1024, need to check) times smaller.
  STATIC mp_obj_t pyb_dac_triangle(mp_obj_t self_in, mp_obj_t freq) {
      pyb_dac_obj_t *self = self_in;
  
      // set TIM6 to trigger the DAC at the given frequency
      TIM6_Config(mp_obj_get_int(freq));
  
      if (self->state != DAC_STATE_BUILTIN_WAVEFORM) {
          // configure DAC to trigger via TIM6
          DAC_ChannelConfTypeDef config;
          config.DAC_Trigger = DAC_TRIGGER_T6_TRGO;
          config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
          HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
          self->state = DAC_STATE_BUILTIN_WAVEFORM;
      }
  
      // set triangle wave generation
      HAL_DACEx_TriangleWaveGenerate(&DAC_Handle, self->dac_channel, DAC_TRIANGLEAMPLITUDE_1023);
      HAL_DAC_SetValue(&DAC_Handle, self->dac_channel, DAC_ALIGN_12B_R, 0x100);
      HAL_DAC_Start(&DAC_Handle, self->dac_channel);
  
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_dac_triangle_obj, pyb_dac_triangle);
  #endif
  
  /// \method write(value)
  /// Direct access to the DAC output (8 bit only at the moment).
  STATIC mp_obj_t pyb_dac_write(mp_obj_t self_in, mp_obj_t val) {
      pyb_dac_obj_t *self = self_in;
  
      if (self->state != DAC_STATE_WRITE_SINGLE) {
          DAC_ChannelConfTypeDef config;
          config.DAC_Trigger = DAC_TRIGGER_NONE;
          config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
          HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
          self->state = DAC_STATE_WRITE_SINGLE;
      }
  
      // DAC output is always 12-bit at the hardware level, and we provide support
      // for multiple bit "resolutions" simply by shifting the input value.
      HAL_DAC_SetValue(&DAC_Handle, self->dac_channel, DAC_ALIGN_12B_R,
          mp_obj_get_int(val) << (12 - self->bits));
  
      HAL_DAC_Start(&DAC_Handle, self->dac_channel);
  
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_dac_write_obj, pyb_dac_write);
  
  #if defined(TIM6)
  /// \method write_timed(data, freq, *, mode=DAC.NORMAL)
  /// Initiates a burst of RAM to DAC using a DMA transfer.
  /// The input data is treated as an array of bytes (8 bit data).
  ///
  /// `freq` can be an integer specifying the frequency to write the DAC
  /// samples at, using Timer(6).  Or it can be an already-initialised
  /// Timer object which is used to trigger the DAC sample.  Valid timers
  /// are 2, 4, 5, 6, 7 and 8.
  ///
  /// `mode` can be `DAC.NORMAL` or `DAC.CIRCULAR`.
  ///
  // TODO add callback argument, to call when transfer is finished
  // TODO add double buffer argument
  //
  // TODO reconsider API, eg: write_trig(data, *, trig=None, loop=False)
  // Then trigger can be timer (preinitialised with desired freq) or pin (extint9),
  // and we can reuse the same timer for both DACs (and maybe also ADC) without
  // setting the freq twice.
  // Can still do 1-liner: dac.write_trig(buf, trig=Timer(6, freq=100), loop=True)
  mp_obj_t pyb_dac_write_timed(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_freq, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DMA_NORMAL} },
      };
  
      // parse args
      pyb_dac_obj_t *self = pos_args[0];
      mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
      mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
  
      // get the data to write
      mp_buffer_info_t bufinfo;
      mp_get_buffer_raise(args[0].u_obj, &bufinfo, MP_BUFFER_READ);
  
      uint32_t dac_trigger;
      if (mp_obj_is_integer(args[1].u_obj)) {
          // set TIM6 to trigger the DAC at the given frequency
          TIM6_Config(mp_obj_get_int(args[1].u_obj));
          dac_trigger = DAC_TRIGGER_T6_TRGO;
      } else {
          // set the supplied timer to trigger the DAC (timer should be initialised)
          dac_trigger = TIMx_Config(args[1].u_obj);
      }
  
      __DMA1_CLK_ENABLE();
  
      DMA_HandleTypeDef DMA_Handle;
      /* Get currently configured dma */
      dma_init_handle(&DMA_Handle, self->tx_dma_descr, (void*)NULL);
      /*
      DMA_Cmd(DMA_Handle->Instance, DISABLE);
      while (DMA_GetCmdStatus(DMA_Handle->Instance) != DISABLE) {
      }
  
      DAC_Cmd(self->dac_channel, DISABLE);
      */
  
      /*
      // DAC channel configuration
      DAC_InitTypeDef DAC_InitStructure;
      DAC_InitStructure.DAC_Trigger = DAC_Trigger_T7_TRGO;
      DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
      DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_TriangleAmplitude_1; // unused, but need to set it to a valid value
      DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
      DAC_Init(self->dac_channel, &DAC_InitStructure);
      */
  
      // Need to deinit DMA first
      DMA_Handle.State = HAL_DMA_STATE_READY;
      HAL_DMA_DeInit(&DMA_Handle);
  
      if (self->bits == 8) {
          DMA_Handle.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
          DMA_Handle.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
      } else {
          DMA_Handle.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
          DMA_Handle.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
      }
      DMA_Handle.Init.Mode = args[2].u_int;
      HAL_DMA_Init(&DMA_Handle);
  
      if (self->dac_channel == DAC_CHANNEL_1) {
          __HAL_LINKDMA(&DAC_Handle, DMA_Handle1, DMA_Handle);
      } else {
          __HAL_LINKDMA(&DAC_Handle, DMA_Handle2, DMA_Handle);
      }
  
      DAC_Handle.Instance = DAC;
      DAC_Handle.State = HAL_DAC_STATE_RESET;
      HAL_DAC_Init(&DAC_Handle);
  
      if (self->state != DAC_STATE_DMA_WAVEFORM + dac_trigger) {
          DAC_ChannelConfTypeDef config;
          config.DAC_Trigger = dac_trigger;
          config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
          HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
          self->state = DAC_STATE_DMA_WAVEFORM + dac_trigger;
      }
  
      if (self->bits == 8) {
          HAL_DAC_Start_DMA(&DAC_Handle, self->dac_channel,
              (uint32_t*)bufinfo.buf, bufinfo.len, DAC_ALIGN_8B_R);
      } else {
          HAL_DAC_Start_DMA(&DAC_Handle, self->dac_channel,
              (uint32_t*)bufinfo.buf, bufinfo.len / 2, DAC_ALIGN_12B_R);
      }
  
      /*
      // enable DMA stream
      DMA_Cmd(DMA_Handle->Instance, ENABLE);
      while (DMA_GetCmdStatus(DMA_Handle->Instance) == DISABLE) {
      }
  
      // enable DAC channel
      DAC_Cmd(self->dac_channel, ENABLE);
  
      // enable DMA for DAC channel
      DAC_DMACmd(self->dac_channel, ENABLE);
      */
  
      //printf("DMA: %p %lu\n", bufinfo.buf, bufinfo.len);
  
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_dac_write_timed_obj, 1, pyb_dac_write_timed);
  #endif
  
  STATIC const mp_rom_map_elem_t pyb_dac_locals_dict_table[] = {
      // instance methods
      { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_dac_init_obj) },
      { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&pyb_dac_deinit_obj) },
      { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&pyb_dac_write_obj) },
      #if defined(TIM6)
      { MP_ROM_QSTR(MP_QSTR_noise), MP_ROM_PTR(&pyb_dac_noise_obj) },
      { MP_ROM_QSTR(MP_QSTR_triangle), MP_ROM_PTR(&pyb_dac_triangle_obj) },
      { MP_ROM_QSTR(MP_QSTR_write_timed), MP_ROM_PTR(&pyb_dac_write_timed_obj) },
      #endif
  
      // class constants
      { MP_ROM_QSTR(MP_QSTR_NORMAL), MP_ROM_INT(DMA_NORMAL) },
      { MP_ROM_QSTR(MP_QSTR_CIRCULAR), MP_ROM_INT(DMA_CIRCULAR) },
  };
  
  STATIC MP_DEFINE_CONST_DICT(pyb_dac_locals_dict, pyb_dac_locals_dict_table);
  
  const mp_obj_type_t pyb_dac_type = {
      { &mp_type_type },
      .name = MP_QSTR_DAC,
      .make_new = pyb_dac_make_new,
      .locals_dict = (mp_obj_dict_t*)&pyb_dac_locals_dict,
  };
  
  #endif // MICROPY_HW_ENABLE_DAC
  