text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2016 Scott Shawcroft
   *
   * 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.
   */
  
  // This file contains all of the Python API definitions for the
  // busio.SPI class.
  
  #include <string.h>
  
  #include "shared-bindings/microcontroller/Pin.h"
  #include "shared-bindings/busio/SPI.h"
  #include "shared-bindings/util.h"
  
  #include "lib/utils/buffer_helper.h"
  #include "lib/utils/context_manager_helpers.h"
  #include "py/mperrno.h"
  #include "py/objproperty.h"
  #include "py/runtime.h"
  #include "supervisor/shared/translate.h"
  
  //| .. currentmodule:: busio
  //|
  //| :class:`SPI` -- a 3-4 wire serial protocol
  //| -----------------------------------------------
  //|
  //| SPI is a serial protocol that has exclusive pins for data in and out of the
  //| master.  It is typically faster than :py:class:`~busio.I2C` because a
  //| separate pin is used to control the active slave rather than a transitted
  //| address. This class only manages three of the four SPI lines: `!clock`,
  //| `!MOSI`, `!MISO`. Its up to the client to manage the appropriate slave
  //| select line. (This is common because multiple slaves can share the `!clock`,
  //| `!MOSI` and `!MISO` lines and therefore the hardware.)
  //|
  //| .. class:: SPI(clock, MOSI=None, MISO=None)
  //|
  //|    Construct an SPI object on the given pins.
  //|
  //|   .. seealso:: Using this class directly requires careful lock management.
  //|       Instead, use :class:`~adafruit_bus_device.spi_device.SPIDevice` to
  //|       manage locks.
  //|
  //|   .. seealso:: Using this class to directly read registers requires manual
  //|       bit unpacking. Instead, use an existing driver or make one with
  //|       :ref:`Register <register-module-reference>` data descriptors.
  //|
  //|   :param ~microcontroller.Pin clock: the pin to use for the clock.
  //|   :param ~microcontroller.Pin MOSI: the Master Out Slave In pin.
  //|   :param ~microcontroller.Pin MISO: the Master In Slave Out pin.
  //|
  
  // TODO(tannewt): Support LSB SPI.
  STATIC mp_obj_t busio_spi_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      busio_spi_obj_t *self = m_new_obj(busio_spi_obj_t);
      self->base.type = &busio_spi_type;
      enum { ARG_clock, ARG_MOSI, ARG_MISO };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_clock, MP_ARG_REQUIRED | MP_ARG_OBJ },
          { MP_QSTR_MOSI, MP_ARG_OBJ, {.u_obj = mp_const_none} },
          { MP_QSTR_MISO, MP_ARG_OBJ, {.u_obj = mp_const_none} },
      };
      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);
      assert_pin(args[ARG_clock].u_obj, false);
      assert_pin(args[ARG_MOSI].u_obj, true);
      assert_pin(args[ARG_MISO].u_obj, true);
      const mcu_pin_obj_t* clock = MP_OBJ_TO_PTR(args[ARG_clock].u_obj);
      assert_pin_free(clock);
      const mcu_pin_obj_t* mosi = MP_OBJ_TO_PTR(args[ARG_MOSI].u_obj);
      assert_pin_free(mosi);
      const mcu_pin_obj_t* miso = MP_OBJ_TO_PTR(args[ARG_MISO].u_obj);
      assert_pin_free(miso);
      common_hal_busio_spi_construct(self, clock, mosi, miso);
      return (mp_obj_t)self;
  }
  
  //|   .. method:: deinit()
  //|
  //|      Turn off the SPI bus.
  //|
  STATIC mp_obj_t busio_spi_obj_deinit(mp_obj_t self_in) {
      busio_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
      common_hal_busio_spi_deinit(self);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_1(busio_spi_deinit_obj, busio_spi_obj_deinit);
  
  //|   .. method:: __enter__()
  //|
  //|     No-op used by Context Managers.
  //|
  //  Provided by context manager helper.
  
  //|   .. method:: __exit__()
  //|
  //|     Automatically deinitializes the hardware when exiting a context. See
  //|     :ref:`lifetime-and-contextmanagers` for more info.
  //|
  STATIC mp_obj_t busio_spi_obj___exit__(size_t n_args, const mp_obj_t *args) {
      (void)n_args;
      common_hal_busio_spi_deinit(args[0]);
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(busio_spi_obj___exit___obj, 4, 4, busio_spi_obj___exit__);
  
  STATIC void check_lock(busio_spi_obj_t *self) {
      asm("");
      if (!common_hal_busio_spi_has_lock(self)) {
          mp_raise_RuntimeError(translate("Function requires lock"));
      }
  }
  
  STATIC void check_for_deinit(busio_spi_obj_t *self) {
      if (common_hal_busio_spi_deinited(self)) {
          raise_deinited_error();
      }
  }
  
  //|   .. method:: configure(*, baudrate=100000, polarity=0, phase=0, bits=8)
  //|
  //|     Configures the SPI bus. The SPI object must be locked.
  //|
  //|     :param int baudrate: the desired clock rate in Hertz. The actual clock rate may be higher or lower
  //|       due to the granularity of available clock settings.
  //|       Check the `frequency` attribute for the actual clock rate.
  //|     :param int polarity: the base state of the clock line (0 or 1)
  //|     :param int phase: the edge of the clock that data is captured. First (0)
  //|       or second (1). Rising or falling depends on clock polarity.
  //|     :param int bits: the number of bits per word
  //|
  //|   .. note:: On the SAMD21, it is possible to set the baudrate to 24 MHz, but that
  //|      speed is not guaranteed to work. 12 MHz is the next available lower speed, and is
  //|      within spec for the SAMD21.
  //|
  //|   .. note:: On the nRF52840, these baudrates are available: 125kHz, 250kHz, 1MHz, 2MHz, 4MHz,
  //|      and 8MHz.
  //|      If you pick a a baudrate other than one of these, the nearest lower
  //|      baudrate will be chosen, with a minimum of 125kHz.
  //|      Two SPI objects may be created, except on the Circuit Playground Bluefruit,
  //|      which allows only one (to allow for an additional I2C object).
  //|
  STATIC mp_obj_t busio_spi_configure(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 100000} },
          { MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_phase, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
      };
      busio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
      check_for_deinit(self);
      check_lock(self);
      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);
  
      uint8_t polarity = args[ARG_polarity].u_int;
      if (polarity != 0 && polarity != 1) {
          mp_raise_ValueError(translate("Invalid polarity"));
      }
      uint8_t phase = args[ARG_phase].u_int;
      if (phase != 0 && phase != 1) {
          mp_raise_ValueError(translate("Invalid phase"));
      }
      uint8_t bits = args[ARG_bits].u_int;
      if (bits != 8 && bits != 9) {
          mp_raise_ValueError(translate("Invalid number of bits"));
      }
  
      if (!common_hal_busio_spi_configure(self, args[ARG_baudrate].u_int,
                                             polarity, phase, bits)) {
          mp_raise_OSError(MP_EIO);
      }
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_configure_obj, 1, busio_spi_configure);
  
  //|   .. method:: try_lock()
  //|
  //|     Attempts to grab the SPI lock. Returns True on success.
  //|
  //|     :return: True when lock has been grabbed
  //|     :rtype: bool
  //|
  STATIC mp_obj_t busio_spi_obj_try_lock(mp_obj_t self_in) {
      busio_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
      return mp_obj_new_bool(common_hal_busio_spi_try_lock(self));
  }
  MP_DEFINE_CONST_FUN_OBJ_1(busio_spi_try_lock_obj, busio_spi_obj_try_lock);
  
  //|   .. method:: unlock()
  //|
  //|     Releases the SPI lock.
  //|
  STATIC mp_obj_t busio_spi_obj_unlock(mp_obj_t self_in) {
      busio_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
      check_for_deinit(self);
      common_hal_busio_spi_unlock(self);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_1(busio_spi_unlock_obj, busio_spi_obj_unlock);
  
  //|   .. method:: write(buffer, *, start=0, end=None)
  //|
  //|     Write the data contained in ``buffer``. The SPI object must be locked.
  //|     If the buffer is empty, nothing happens.
  //|
  //|     :param bytearray buffer: Write out the data in this buffer
  //|     :param int start: Start of the slice of ``buffer`` to write out: ``buffer[start:end]``
  //|     :param int end: End of the slice; this index is not included. Defaults to ``len(buffer)``
  //|
  STATIC mp_obj_t busio_spi_write(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_buffer, ARG_start, ARG_end };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_buffer,     MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_start,      MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_end,        MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
      };
      busio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
      check_for_deinit(self);
      check_lock(self);
      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);
  
      mp_buffer_info_t bufinfo;
      mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_READ);
      int32_t start = args[ARG_start].u_int;
      size_t length = bufinfo.len;
      normalize_buffer_bounds(&start, args[ARG_end].u_int, &length);
  
      if (length == 0) {
          return mp_const_none;
      }
  
      bool ok = common_hal_busio_spi_write(self, ((uint8_t*)bufinfo.buf) + start, length);
      if (!ok) {
          mp_raise_OSError(MP_EIO);
      }
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_write_obj, 2, busio_spi_write);
  
  
  //|   .. method:: readinto(buffer, *, start=0, end=None, write_value=0)
  //|
  //|     Read into ``buffer`` while writing ``write_value`` for each byte read.
  //|     The SPI object must be locked.
  //|     If the number of bytes to read is 0, nothing happens.
  //|
  //|     :param bytearray buffer: Read data into this buffer
  //|     :param int start: Start of the slice of ``buffer`` to read into: ``buffer[start:end]``
  //|     :param int end: End of the slice; this index is not included. Defaults to ``len(buffer)``
  //|     :param int write_value: Value to write while reading. (Usually ignored.)
  //|
  STATIC mp_obj_t busio_spi_readinto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_buffer, ARG_start, ARG_end, ARG_write_value };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_buffer,     MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_start,      MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_end,        MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
          { MP_QSTR_write_value,MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
      };
      busio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
      check_for_deinit(self);
      check_lock(self);
      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);
  
      mp_buffer_info_t bufinfo;
      mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_WRITE);
      int32_t start = args[ARG_start].u_int;
      size_t length = bufinfo.len;
      normalize_buffer_bounds(&start, args[ARG_end].u_int, &length);
  
      if (length == 0) {
          return mp_const_none;
      }
  
      bool ok = common_hal_busio_spi_read(self, ((uint8_t*)bufinfo.buf) + start, length, args[ARG_write_value].u_int);
      if (!ok) {
          mp_raise_OSError(MP_EIO);
      }
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_readinto_obj, 2, busio_spi_readinto);
  
  //|   .. method:: write_readinto(buffer_out, buffer_in, *, out_start=0, out_end=None, in_start=0, in_end=None)
  //|
  //|     Write out the data in ``buffer_out`` while simultaneously reading data into ``buffer_in``.
  //|     The SPI object must be locked.
  //|     The lengths of the slices defined by ``buffer_out[out_start:out_end]`` and ``buffer_in[in_start:in_end]``
  //|     must be equal.
  //|     If buffer slice lengths are both 0, nothing happens.
  //|
  //|     :param bytearray buffer_out: Write out the data in this buffer
  //|     :param bytearray buffer_in: Read data into this buffer
  //|     :param int out_start: Start of the slice of buffer_out to write out: ``buffer_out[out_start:out_end]``
  //|     :param int out_end: End of the slice; this index is not included. Defaults to ``len(buffer_out)``
  //|     :param int in_start: Start of the slice of ``buffer_in`` to read into: ``buffer_in[in_start:in_end]``
  //|     :param int in_end: End of the slice; this index is not included. Defaults to ``len(buffer_in)``
  //|
  STATIC mp_obj_t busio_spi_write_readinto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_buffer_out, ARG_buffer_in, ARG_out_start, ARG_out_end, ARG_in_start, ARG_in_end };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_buffer_out,    MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_buffer_in,     MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_out_start,     MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_out_end,       MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
          { MP_QSTR_in_start,      MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_in_end,        MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
      };
      busio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
      check_for_deinit(self);
      check_lock(self);
      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);
  
      mp_buffer_info_t buf_out_info;
      mp_get_buffer_raise(args[ARG_buffer_out].u_obj, &buf_out_info, MP_BUFFER_READ);
      int32_t out_start = args[ARG_out_start].u_int;
      size_t out_length = buf_out_info.len;
      normalize_buffer_bounds(&out_start, args[ARG_out_end].u_int, &out_length);
  
      mp_buffer_info_t buf_in_info;
      mp_get_buffer_raise(args[ARG_buffer_in].u_obj, &buf_in_info, MP_BUFFER_WRITE);
      int32_t in_start = args[ARG_in_start].u_int;
      size_t in_length = buf_in_info.len;
      normalize_buffer_bounds(&in_start, args[ARG_in_end].u_int, &in_length);
  
      if (out_length != in_length) {
          mp_raise_ValueError(translate("buffer slices must be of equal length"));
      }
  
      if (out_length == 0) {
          return mp_const_none;
      }
  
      bool ok = common_hal_busio_spi_transfer(self,
                                              ((uint8_t*)buf_out_info.buf) + out_start,
                                              ((uint8_t*)buf_in_info.buf) + in_start,
                                              out_length);
      if (!ok) {
          mp_raise_OSError(MP_EIO);
      }
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_write_readinto_obj, 2, busio_spi_write_readinto);
  
  //|   .. attribute:: frequency
  //|
  //|     The actual SPI bus frequency. This may not match the frequency requested
  //|     due to internal limitations.
  //|
  STATIC mp_obj_t busio_spi_obj_get_frequency(mp_obj_t self_in) {
      busio_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
      check_for_deinit(self);
      return MP_OBJ_NEW_SMALL_INT(common_hal_busio_spi_get_frequency(self));
  }
  MP_DEFINE_CONST_FUN_OBJ_1(busio_spi_get_frequency_obj, busio_spi_obj_get_frequency);
  
  const mp_obj_property_t busio_spi_frequency_obj = {
      .base.type = &mp_type_property,
      .proxy = {(mp_obj_t)&busio_spi_get_frequency_obj,
                (mp_obj_t)&mp_const_none_obj,
                (mp_obj_t)&mp_const_none_obj},
  };
  
  STATIC const mp_rom_map_elem_t busio_spi_locals_dict_table[] = {
      { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&busio_spi_deinit_obj) },
      { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
      { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&busio_spi_obj___exit___obj) },
  
      { MP_ROM_QSTR(MP_QSTR_configure), MP_ROM_PTR(&busio_spi_configure_obj) },
      { MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&busio_spi_try_lock_obj) },
      { MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&busio_spi_unlock_obj) },
  
      { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&busio_spi_readinto_obj) },
      { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&busio_spi_write_obj) },
      { MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&busio_spi_write_readinto_obj) },
      { MP_ROM_QSTR(MP_QSTR_frequency), MP_ROM_PTR(&busio_spi_frequency_obj) }
  };
  STATIC MP_DEFINE_CONST_DICT(busio_spi_locals_dict, busio_spi_locals_dict_table);
  
  const mp_obj_type_t busio_spi_type = {
     { &mp_type_type },
     .name = MP_QSTR_SPI,
     .make_new = busio_spi_make_new,
     .locals_dict = (mp_obj_dict_t*)&busio_spi_locals_dict,
  };
  