/**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */
#ifdef ARDUINO_ARCH_ESP32

#include "../../inc/MarlinConfigPre.h"

#include "i2s.h"

#include "../shared/Marduino.h"
#include <driver/periph_ctrl.h>
#include <rom/lldesc.h>
#include <soc/i2s_struct.h>
#include <freertos/queue.h>
#include "../../module/stepper.h"

#define DMA_BUF_COUNT 8                                // number of DMA buffers to store data
#define DMA_BUF_LEN   4092                             // maximum size in bytes
#define I2S_SAMPLE_SIZE 4                              // 4 bytes, 32 bits per sample
#define DMA_SAMPLE_COUNT DMA_BUF_LEN / I2S_SAMPLE_SIZE // number of samples per buffer

typedef enum {
  I2S_NUM_0 = 0x0,  /*!< I2S 0*/
  I2S_NUM_1 = 0x1,  /*!< I2S 1*/
  I2S_NUM_MAX,
} i2s_port_t;

typedef struct {
  uint32_t     **buffers;
  uint32_t     *current;
  uint32_t     rw_pos;
  lldesc_t     **desc;
  xQueueHandle queue;
} i2s_dma_t;

static portMUX_TYPE i2s_spinlock[I2S_NUM_MAX] = {portMUX_INITIALIZER_UNLOCKED, portMUX_INITIALIZER_UNLOCKED};
static i2s_dev_t* I2S[I2S_NUM_MAX] = {&I2S0, &I2S1};
static i2s_dma_t dma;

// output value
uint32_t i2s_port_data = 0;

#define I2S_ENTER_CRITICAL()  portENTER_CRITICAL(&i2s_spinlock[i2s_num])
#define I2S_EXIT_CRITICAL()   portEXIT_CRITICAL(&i2s_spinlock[i2s_num])

static inline void gpio_matrix_out_check(uint32_t gpio, uint32_t signal_idx, bool out_inv, bool oen_inv) {
  //if pin = -1, do not need to configure
  if (gpio != -1) {
    PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[gpio], PIN_FUNC_GPIO);
    gpio_set_direction((gpio_num_t)gpio, (gpio_mode_t)GPIO_MODE_DEF_OUTPUT);
    gpio_matrix_out(gpio, signal_idx, out_inv, oen_inv);
  }
}

static esp_err_t i2s_reset_fifo(i2s_port_t i2s_num) {
  I2S_ENTER_CRITICAL();
  I2S[i2s_num]->conf.rx_fifo_reset = 1;
  I2S[i2s_num]->conf.rx_fifo_reset = 0;
  I2S[i2s_num]->conf.tx_fifo_reset = 1;
  I2S[i2s_num]->conf.tx_fifo_reset = 0;
  I2S_EXIT_CRITICAL();

  return ESP_OK;
}

esp_err_t i2s_start(i2s_port_t i2s_num) {
  //start DMA link
  I2S_ENTER_CRITICAL();
  i2s_reset_fifo(i2s_num);

  //reset dma
  I2S[i2s_num]->lc_conf.in_rst = 1;
  I2S[i2s_num]->lc_conf.in_rst = 0;
  I2S[i2s_num]->lc_conf.out_rst = 1;
  I2S[i2s_num]->lc_conf.out_rst = 0;

  I2S[i2s_num]->conf.tx_reset = 1;
  I2S[i2s_num]->conf.tx_reset = 0;
  I2S[i2s_num]->conf.rx_reset = 1;
  I2S[i2s_num]->conf.rx_reset = 0;

  I2S[i2s_num]->int_clr.val = 0xFFFFFFFF;
  I2S[i2s_num]->out_link.start = 1;
  I2S[i2s_num]->conf.tx_start = 1;
  I2S_EXIT_CRITICAL();

  return ESP_OK;
}

esp_err_t i2s_stop(i2s_port_t i2s_num) {
  I2S_ENTER_CRITICAL();
  I2S[i2s_num]->out_link.stop = 1;
  I2S[i2s_num]->conf.tx_start = 0;

  I2S[i2s_num]->int_clr.val = I2S[i2s_num]->int_st.val; //clear pending interrupt
  I2S_EXIT_CRITICAL();

  return ESP_OK;
}

static void IRAM_ATTR i2s_intr_handler_default(void *arg) {
  int dummy;
  lldesc_t *finish_desc;
  portBASE_TYPE high_priority_task_awoken = pdFALSE;

  if (I2S0.int_st.out_eof) {
    // Get the descriptor of the last item in the linkedlist
    finish_desc = (lldesc_t*) I2S0.out_eof_des_addr;

    // If the queue is full it's because we have an underflow,
    // more than buf_count isr without new data, remove the front buffer
    if (xQueueIsQueueFullFromISR(dma.queue))
      xQueueReceiveFromISR(dma.queue, &dummy, &high_priority_task_awoken);

    xQueueSendFromISR(dma.queue, (void *)(&finish_desc->buf), &high_priority_task_awoken);
  }

  if (high_priority_task_awoken == pdTRUE) portYIELD_FROM_ISR();

  // clear interrupt
  I2S0.int_clr.val = I2S0.int_st.val; //clear pending interrupt
}

void stepperTask(void* parameter) {
  uint32_t remaining = 0;

  while (1) {
    xQueueReceive(dma.queue, &dma.current, portMAX_DELAY);
    dma.rw_pos = 0;

    while (dma.rw_pos < DMA_SAMPLE_COUNT) {
      // Fill with the port data post pulse_phase until the next step
      if (remaining) {
        i2s_push_sample();
        remaining--;
      }
      else {
        Stepper::pulse_phase_isr();
        remaining = Stepper::block_phase_isr();
      }
    }
  }
}

int i2s_init() {
  periph_module_enable(PERIPH_I2S0_MODULE);

  /**
   * Each i2s transfer will take
   *   fpll = PLL_D2_CLK      -- clka_en = 0
   *
   *   fi2s = fpll / N + b/a  -- N = clkm_div_num
   *   fi2s = 160MHz / 2
   *   fi2s = 80MHz
   *
   *   fbclk = fi2s / M   -- M = tx_bck_div_num
   *   fbclk = 80MHz / 2
   *   fbclk = 40MHz
   *
   *   fwclk = fbclk / 32
   *
   *   for fwclk = 250kHz (4µS pulse time)
   *      N = 10
   *      M = 20
   */

  // Allocate the array of pointers to the buffers
  dma.buffers = (uint32_t **)malloc(sizeof(uint32_t*) * DMA_BUF_COUNT);
  if (dma.buffers == nullptr) return -1;

  // Allocate each buffer that can be used by the DMA controller
  for (int buf_idx = 0; buf_idx < DMA_BUF_COUNT; buf_idx++) {
    dma.buffers[buf_idx] = (uint32_t*) heap_caps_calloc(1, DMA_BUF_LEN, MALLOC_CAP_DMA);
    if (dma.buffers[buf_idx] == nullptr) return -1;
  }

  // Allocate the array of DMA descriptors
  dma.desc = (lldesc_t**) malloc(sizeof(lldesc_t*) * DMA_BUF_COUNT);
  if (dma.desc == nullptr) return -1;

  // Allocate each DMA descriptor that will be used by the DMA controller
  for (int buf_idx = 0; buf_idx < DMA_BUF_COUNT; buf_idx++) {
    dma.desc[buf_idx] = (lldesc_t*) heap_caps_malloc(sizeof(lldesc_t), MALLOC_CAP_DMA);
    if (dma.desc[buf_idx] == nullptr) return -1;
  }

  // Initialize
  for (int buf_idx = 0; buf_idx < DMA_BUF_COUNT; buf_idx++) {
    dma.desc[buf_idx]->owner = 1;
    dma.desc[buf_idx]->eof = 1; // set to 1 will trigger the interrupt
    dma.desc[buf_idx]->sosf = 0;
    dma.desc[buf_idx]->length = DMA_BUF_LEN;
    dma.desc[buf_idx]->size = DMA_BUF_LEN;
    dma.desc[buf_idx]->buf = (uint8_t *) dma.buffers[buf_idx];
    dma.desc[buf_idx]->offset = 0;
    dma.desc[buf_idx]->empty = (uint32_t)((buf_idx < (DMA_BUF_COUNT - 1)) ? (dma.desc[buf_idx + 1]) : dma.desc[0]);
  }

  dma.queue = xQueueCreate(DMA_BUF_COUNT, sizeof(uint32_t *));

  // Set the first DMA descriptor
  I2S0.out_link.addr = (uint32_t)dma.desc[0];

  // stop i2s
  i2s_stop(I2S_NUM_0);

  // configure I2S data port interface.
  i2s_reset_fifo(I2S_NUM_0);

  //reset i2s
  I2S0.conf.tx_reset = 1;
  I2S0.conf.tx_reset = 0;
  I2S0.conf.rx_reset = 1;
  I2S0.conf.rx_reset = 0;

  //reset dma
  I2S0.lc_conf.in_rst = 1;
  I2S0.lc_conf.in_rst = 0;
  I2S0.lc_conf.out_rst = 1;
  I2S0.lc_conf.out_rst = 0;

  //Enable and configure DMA
  I2S0.lc_conf.check_owner = 0;
  I2S0.lc_conf.out_loop_test = 0;
  I2S0.lc_conf.out_auto_wrback = 0;
  I2S0.lc_conf.out_data_burst_en = 0;
  I2S0.lc_conf.outdscr_burst_en = 0;
  I2S0.lc_conf.out_no_restart_clr = 0;
  I2S0.lc_conf.indscr_burst_en = 0;
  I2S0.lc_conf.out_eof_mode = 1;

  I2S0.conf2.lcd_en = 0;
  I2S0.conf2.camera_en = 0;
  I2S0.pdm_conf.pcm2pdm_conv_en = 0;
  I2S0.pdm_conf.pdm2pcm_conv_en = 0;

  I2S0.fifo_conf.dscr_en = 0;

  I2S0.conf_chan.tx_chan_mod = (
    #if ENABLED(I2S_STEPPER_SPLIT_STREAM)
      4
    #else
      0
    #endif
  );
  I2S0.fifo_conf.tx_fifo_mod = 0;
  I2S0.conf.tx_mono = 0;

  I2S0.conf_chan.rx_chan_mod = 0;
  I2S0.fifo_conf.rx_fifo_mod = 0;
  I2S0.conf.rx_mono = 0;

  I2S0.fifo_conf.dscr_en = 1; //connect dma to fifo

  I2S0.conf.tx_start = 0;
  I2S0.conf.rx_start = 0;

  I2S0.conf.tx_msb_right = 1;
  I2S0.conf.tx_right_first = 1;

  I2S0.conf.tx_slave_mod = 0; // Master
  I2S0.fifo_conf.tx_fifo_mod_force_en = 1;

  I2S0.pdm_conf.rx_pdm_en = 0;
  I2S0.pdm_conf.tx_pdm_en = 0;

  I2S0.conf.tx_short_sync = 0;
  I2S0.conf.rx_short_sync = 0;
  I2S0.conf.tx_msb_shift = 0;
  I2S0.conf.rx_msb_shift = 0;

  // set clock
  I2S0.clkm_conf.clka_en = 0;       // Use PLL/2 as reference
  I2S0.clkm_conf.clkm_div_num = 10; // minimum value of 2, reset value of 4, max 256
  I2S0.clkm_conf.clkm_div_a = 0;    // 0 at reset, what about divide by 0? (not an issue)
  I2S0.clkm_conf.clkm_div_b = 0;    // 0 at reset

  // fbck = fi2s / tx_bck_div_num
  I2S0.sample_rate_conf.tx_bck_div_num = 2; // minimum value of 2 defaults to 6

  // Enable TX interrupts
  I2S0.int_ena.out_eof = 1;
  I2S0.int_ena.out_dscr_err = 0;
  I2S0.int_ena.out_total_eof = 0;
  I2S0.int_ena.out_done = 0;

  // Allocate and Enable the I2S interrupt
  intr_handle_t i2s_isr_handle;
  esp_intr_alloc(ETS_I2S0_INTR_SOURCE, 0, i2s_intr_handler_default, nullptr, &i2s_isr_handle);
  esp_intr_enable(i2s_isr_handle);

  // Create the task that will feed the buffer
  xTaskCreatePinnedToCore(stepperTask, "StepperTask", 10000, nullptr, 1, nullptr, CONFIG_ARDUINO_RUNNING_CORE); // run I2S stepper task on same core as rest of Marlin

  // Route the i2s pins to the appropriate GPIO
  gpio_matrix_out_check(I2S_DATA, I2S0O_DATA_OUT23_IDX, 0, 0);
  gpio_matrix_out_check(I2S_BCK, I2S0O_BCK_OUT_IDX, 0, 0);
  gpio_matrix_out_check(I2S_WS, I2S0O_WS_OUT_IDX, 0, 0);

  // Start the I2S peripheral
  return i2s_start(I2S_NUM_0);
}

void i2s_write(uint8_t pin, uint8_t val) {
  #if ENABLED(I2S_STEPPER_SPLIT_STREAM)
    if (pin >= 16) {
      SET_BIT_TO(I2S0.conf_single_data, pin, val);
      return;
    }
  #endif
  SET_BIT_TO(i2s_port_data, pin, val);
}

uint8_t i2s_state(uint8_t pin) {
  #if ENABLED(I2S_STEPPER_SPLIT_STREAM)
    if (pin >= 16) return TEST(I2S0.conf_single_data, pin);
  #endif
  return TEST(i2s_port_data, pin);
}

void i2s_push_sample() {
  dma.current[dma.rw_pos++] = i2s_port_data;
}

#endif // ARDUINO_ARCH_ESP32