text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2016-2018 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 <string.h>
  
  #include "py/runtime.h"
  #include "py/mphal.h"
  #include "py/mperrno.h"
  #include "extmod/machine_i2c.h"
  #include "i2c.h"
  
  #if MICROPY_HW_ENABLE_HW_I2C
  
  STATIC const mp_obj_type_t machine_hard_i2c_type;
  
  #if defined(STM32F0) || defined(STM32F4) || defined(STM32F7)
  
  typedef struct _machine_hard_i2c_obj_t {
      mp_obj_base_t base;
      i2c_t *i2c;
      mp_hal_pin_obj_t scl;
      mp_hal_pin_obj_t sda;
  } machine_hard_i2c_obj_t;
  
  STATIC const machine_hard_i2c_obj_t machine_hard_i2c_obj[] = {
      #if defined(MICROPY_HW_I2C1_SCL)
      {{&machine_hard_i2c_type}, I2C1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA},
      #else
      {{NULL}, NULL, NULL, NULL},
      #endif
      #if defined(MICROPY_HW_I2C2_SCL)
      {{&machine_hard_i2c_type}, I2C2, MICROPY_HW_I2C2_SCL, MICROPY_HW_I2C2_SDA},
      #else
      {{NULL}, NULL, NULL, NULL},
      #endif
      #if defined(MICROPY_HW_I2C3_SCL)
      {{&machine_hard_i2c_type}, I2C3, MICROPY_HW_I2C3_SCL, MICROPY_HW_I2C3_SDA},
      #else
      {{NULL}, NULL, NULL, NULL},
      #endif
      #if defined(MICROPY_HW_I2C4_SCL)
      {{&machine_hard_i2c_type}, I2C4, MICROPY_HW_I2C4_SCL, MICROPY_HW_I2C4_SDA},
      #else
      {{NULL}, NULL, NULL, NULL},
      #endif
  };
  
  STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
      machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
  
      #if defined(STM32F4)
  
      uint32_t freq = self->i2c->CR2 & 0x3f;
      uint32_t ccr = self->i2c->CCR;
      if (ccr & 0x8000) {
          // Fast mode, assume duty cycle of 16/9
          freq = freq * 40000 / (ccr & 0xfff);
      } else {
          // Standard mode
          freq = freq * 500000 / (ccr & 0xfff);
      }
  
      mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u)",
          self - &machine_hard_i2c_obj[0] + 1,
          mp_hal_pin_name(self->scl), mp_hal_pin_name(self->sda),
          freq);
  
      #else
  
      uint32_t timingr = self->i2c->TIMINGR;
      uint32_t presc = timingr >> 28;
      uint32_t sclh = timingr >> 8 & 0xff;
      uint32_t scll = timingr & 0xff;
      uint32_t freq = HAL_RCC_GetPCLK1Freq() / (presc + 1) / (sclh + scll + 2);
      mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u, timingr=0x%08x)",
          self - &machine_hard_i2c_obj[0] + 1,
          mp_hal_pin_name(self->scl), mp_hal_pin_name(self->sda),
          freq, timingr);
  
      #endif
  }
  
  void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout) {
      (void)timeout;
      i2c_init(self->i2c, self->scl, self->sda, freq);
  }
  
  int machine_hard_i2c_readfrom(mp_obj_base_t *self_in, uint16_t addr, uint8_t *dest, size_t len, bool stop) {
      machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
      return i2c_readfrom(self->i2c, addr, dest, len, stop);
  }
  
  int machine_hard_i2c_writeto(mp_obj_base_t *self_in, uint16_t addr, const uint8_t *src, size_t len, bool stop) {
      machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
      return i2c_writeto(self->i2c, addr, src, len, stop);
  }
  
  #else
  
  // No hardware I2C driver for this MCU so use the software implementation
  
  typedef mp_machine_soft_i2c_obj_t machine_hard_i2c_obj_t;
  
  STATIC machine_hard_i2c_obj_t machine_hard_i2c_obj[] = {
      #if defined(MICROPY_HW_I2C1_SCL)
      {{&machine_hard_i2c_type}, 1, 500, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA},
      #else
      {{NULL}, 0, 0, NULL, NULL},
      #endif
      #if defined(MICROPY_HW_I2C2_SCL)
      {{&machine_hard_i2c_type}, 1, 500, MICROPY_HW_I2C2_SCL, MICROPY_HW_I2C2_SDA},
      #else
      {{NULL}, 0, 0, NULL, NULL},
      #endif
      #if defined(MICROPY_HW_I2C3_SCL)
      {{&machine_hard_i2c_type}, 1, 500, MICROPY_HW_I2C3_SCL, MICROPY_HW_I2C3_SDA},
      #else
      {{NULL}, 0, 0, NULL, NULL},
      #endif
      #if defined(MICROPY_HW_I2C4_SCL)
      {{&machine_hard_i2c_type}, 1, 500, MICROPY_HW_I2C4_SCL, MICROPY_HW_I2C4_SDA},
      #else
      {{NULL}, 0, 0, NULL, NULL},
      #endif
  };
  
  STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
      machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
      mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u, timeout=%u)",
          self - &machine_hard_i2c_obj[0] + 1,
          self->scl->name, self->sda->name, 500000 / self->us_delay, self->us_timeout);
  }
  
  STATIC void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout) {
      // set parameters
      if (freq >= 1000000) {
          // allow fastest possible bit-bang rate
          self->us_delay = 0;
      } else {
          self->us_delay = 500000 / freq;
          if (self->us_delay == 0) {
              self->us_delay = 1;
          }
      }
  
      self->us_timeout = timeout;
  
      // init pins
      mp_hal_pin_open_drain(self->scl);
      mp_hal_pin_open_drain(self->sda);
  }
  
  #define machine_hard_i2c_readfrom mp_machine_soft_i2c_readfrom
  #define machine_hard_i2c_writeto mp_machine_soft_i2c_writeto
  
  #endif
  
  /******************************************************************************/
  /* MicroPython bindings for machine API                                       */
  
  mp_obj_t machine_hard_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
      // parse args
      enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ },
          { MP_QSTR_scl, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_sda, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
          { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1000} },
      };
      mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
      mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
  
      // work out i2c bus
      int i2c_id = 0;
      if (MP_OBJ_IS_STR(args[ARG_id].u_obj)) {
          const char *port = mp_obj_str_get_str(args[ARG_id].u_obj);
          if (0) {
          #ifdef MICROPY_HW_I2C1_NAME
          } else if (strcmp(port, MICROPY_HW_I2C1_NAME) == 0) {
              i2c_id = 1;
          #endif
          #ifdef MICROPY_HW_I2C2_NAME
          } else if (strcmp(port, MICROPY_HW_I2C2_NAME) == 0) {
              i2c_id = 2;
          #endif
          #ifdef MICROPY_HW_I2C3_NAME
          } else if (strcmp(port, MICROPY_HW_I2C3_NAME) == 0) {
              i2c_id = 3;
          #endif
          } else {
              nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
                  "I2C(%s) doesn't exist", port));
          }
      } else {
          i2c_id = mp_obj_get_int(args[ARG_id].u_obj);
          if (i2c_id < 1 || i2c_id > MP_ARRAY_SIZE(machine_hard_i2c_obj)
              || machine_hard_i2c_obj[i2c_id - 1].base.type == NULL) {
              nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
                  "I2C(%d) doesn't exist", i2c_id));
          }
      }
  
      // get static peripheral object
      machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t*)&machine_hard_i2c_obj[i2c_id - 1];
  
      // here we would check the scl/sda pins and configure them, but it's not implemented
      if (args[ARG_scl].u_obj != MP_OBJ_NULL || args[ARG_sda].u_obj != MP_OBJ_NULL) {
          mp_raise_ValueError("explicit choice of scl/sda is not implemented");
      }
  
      // initialise the I2C peripheral
      machine_hard_i2c_init(self, args[ARG_freq].u_int, args[ARG_timeout].u_int);
  
      return MP_OBJ_FROM_PTR(self);
  }
  
  STATIC const mp_machine_i2c_p_t machine_hard_i2c_p = {
      .readfrom = machine_hard_i2c_readfrom,
      .writeto = machine_hard_i2c_writeto,
  };
  
  STATIC const mp_obj_type_t machine_hard_i2c_type = {
      { &mp_type_type },
      .name = MP_QSTR_I2C,
      .print = machine_hard_i2c_print,
      .make_new = machine_hard_i2c_make_new,
      .protocol = &machine_hard_i2c_p,
      .locals_dict = (mp_obj_dict_t*)&mp_machine_soft_i2c_locals_dict,
  };
  
  #endif // MICROPY_HW_ENABLE_HW_I2C
  