jerryscript/targets/os/mbedos5/jerryscript-mbed/jerryscript-mbed-drivers/source/I2C-js.cpp

/* Copyright JS Foundation and other contributors, http://js.foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "jerryscript-mbed-drivers/I2C-js.h"

#include "jerryscript-mbed-library-registry/wrap_tools.h"
#include "jerryscript-mbed-util/logging.h"
#include "mbed.h"

/**
 * I2C#destructor
 *
 * Called if/when the I2C object is GC'ed.
 */
void
NAME_FOR_CLASS_NATIVE_DESTRUCTOR (I2C) (void *void_ptr, jerry_object_native_info_t *info_p)
{
  (void) info_p;
  delete static_cast<I2C *> (void_ptr);
}

/**
 * Type infomation of the native I2C pointer
 *
 * Set I2C#destructor as the free callback.
 */
static const jerry_object_native_info_t native_obj_type_info = { .free_cb = NAME_FOR_CLASS_NATIVE_DESTRUCTOR (I2C) };

/**
 * I2C#frequency (native JavaScript method)
 *
 * Set the frequency of the I2C bus.
 *
 * @param frequency New I2C Frequency
 */
DECLARE_CLASS_FUNCTION (I2C, frequency)
{
  CHECK_ARGUMENT_COUNT (I2C, frequency, (args_count == 1));
  CHECK_ARGUMENT_TYPE_ALWAYS (I2C, frequency, 0, number);

  // Unwrap native I2C object
  void *void_ptr = jerry_object_get_native_ptr (call_info_p->this_value, &native_obj_type_info);

  if (void_ptr == NULL)
  {
    return jerry_throw_sz (JERRY_ERROR_TYPE, "Failed to get native I2C pointer");
  }

  I2C *native_ptr = static_cast<I2C *> (void_ptr);

  int hz = jerry_value_as_number (args[0]);
  native_ptr->frequency (hz);

  return jerry_undefined ();
}

/**
 * I2C#read (native JavaScript method)
 *
 * Read data from the I2C bus.
 *
 * @overload I2C#read(int)
 * Read a single byte from the I2C bus
 *
 * @param ack indicates if the byte is to be acknowledged (1 => acknowledge)
 *
 * @returns array: Data read from the I2C bus
 *
 * @overload I2C#read(int, array, int)
 * Read a series of bytes from the I2C bus
 *
 * @param address I2C address to read from
 * @param data Array to read into
 * @param length Length of data to read
 *
 * @returns array: Data read from the I2C bus
 */
DECLARE_CLASS_FUNCTION (I2C, read)
{
  CHECK_ARGUMENT_COUNT (I2C, read, (args_count == 1 || args_count == 3 || args_count == 4));

  if (args_count == 1)
  {
    CHECK_ARGUMENT_TYPE_ALWAYS (I2C, read, 0, number);
    void *void_ptr = jerry_object_get_native_ptr (call_info_p->this_value, &native_obj_type_info);

    if (void_ptr == NULL)
    {
      return jerry_throw_sz (JERRY_ERROR_TYPE, "Failed to get native I2C pointer");
    }

    I2C *native_ptr = static_cast<I2C *> (void_ptr);

    int data = jerry_value_as_number (args[0]);
    int result = native_ptr->read (data);

    return jerry_number (result);
  }
  else
  {
    CHECK_ARGUMENT_TYPE_ALWAYS (I2C, read, 0, number);
    CHECK_ARGUMENT_TYPE_ALWAYS (I2C, read, 1, array);
    CHECK_ARGUMENT_TYPE_ALWAYS (I2C, read, 2, number);

    CHECK_ARGUMENT_TYPE_ON_CONDITION (I2C, read, 3, boolean, (args_count == 4));

    void *void_ptr = jerry_object_get_native_ptr (call_info_p->this_value, &native_obj_type_info);

    if (void_ptr == NULL)
    {
      return jerry_throw_sz (JERRY_ERROR_TYPE, "Failed to get native I2C pointer");
    }

    I2C *native_ptr = static_cast<I2C *> (void_ptr);

    const uint32_t data_len = jerry_array_length (args[1]);

    int address = jerry_value_as_number (args[0]);
    int length = jerry_value_as_number (args[2]);

    char *data = new char[data_len];

    bool repeated = false;
    if (args_count == 4)
    {
      repeated = jerry_value_is_true (args[3]);
    }

    int result = native_ptr->read (address, data, length, repeated);

    jerry_value_t out_array = jerry_array (data_len);

    for (uint32_t i = 0; i < data_len; i++)
    {
      jerry_value_t val = jerry_number (double (data[i]));
      jerry_value_free (jerry_object_set_index (out_array, i, val));
      jerry_value_free (val);
    }

    delete[] data;

    if (result == 0)
    {
      // ACK
      return out_array;
    }
    else
    {
      // NACK
      const char *error_msg = "NACK received from I2C bus";

      jerry_value_free (out_array);
      return jerry_throw_sz (JERRY_ERROR_COMMON, error_msg);
    }
  }
}

/**
 * I2C#write (native JavaScript method)
 *
 * @overload I2C#write(int)
 * Write a single byte to the I2C bus
 *
 * @param data Data byte to write to the I2C bus
 *
 * @returns 1 on success, 0 on failure
 *
 * @overload I2C#write(int, array, int, bool)
 * Write an array of data to a certain address on the I2C bus
 *
 * @param address 8-bit I2C slave address
 * @param data Array of bytes to send
 * @param length Length of data to write
 * @param repeated (optional) If true, do not send stop at end.
 *
 * @returns 0 on success, non-0 on failure
 */
DECLARE_CLASS_FUNCTION (I2C, write)
{
  CHECK_ARGUMENT_COUNT (I2C, write, (args_count == 1 || args_count == 3 || args_count == 4));

  if (args_count == 1)
  {
    CHECK_ARGUMENT_TYPE_ALWAYS (I2C, write, 0, number);

    // Extract native I2C object
    void *void_ptr = jerry_object_get_native_ptr (call_info_p->this_value, &native_obj_type_info);

    if (void_ptr == NULL)
    {
      return jerry_throw_sz (JERRY_ERROR_TYPE, "Failed to get native I2C pointer");
    }

    I2C *native_ptr = static_cast<I2C *> (void_ptr);

    // Unwrap arguments
    int data = jerry_value_as_number (args[0]);

    int result = native_ptr->write (data);
    return jerry_number (result);
  }
  else
  {
    // 3 or 4
    CHECK_ARGUMENT_TYPE_ALWAYS (I2C, write, 0, number);
    CHECK_ARGUMENT_TYPE_ALWAYS (I2C, write, 1, array);
    CHECK_ARGUMENT_TYPE_ALWAYS (I2C, write, 2, number);
    CHECK_ARGUMENT_TYPE_ON_CONDITION (I2C, write, 3, boolean, (args_count == 4));

    // Extract native I2C object
    void *void_ptr = jerry_object_get_native_ptr (call_info_p->this_value, &native_obj_type_info);

    if (void_ptr != NULL)
    {
      return jerry_throw_sz (JERRY_ERROR_TYPE, "Failed to get native I2C pointer");
    }

    I2C *native_ptr = static_cast<I2C *> (void_ptr);

    // Unwrap arguments
    int address = jerry_value_as_number (args[0]);
    const uint32_t data_len = jerry_array_length (args[1]);
    int length = jerry_value_as_number (args[2]);
    bool repeated = args_count == 4 && jerry_value_is_true (args[3]);

    // Construct data byte array
    char *data = new char[data_len];
    for (uint32_t i = 0; i < data_len; i++)
    {
      data[i] = jerry_value_as_number (jerry_object_get_index (args[1], i));
    }

    int result = native_ptr->write (address, data, length, repeated);

    // free dynamically allocated resources
    delete[] data;

    return jerry_number (result);
  }
}

/**
 * I2C#start (native JavaScript method)
 *
 * Creates a start condition on the I2C bus.
 */
DECLARE_CLASS_FUNCTION (I2C, start)
{
  CHECK_ARGUMENT_COUNT (I2C, start, (args_count == 0));

  // Extract native I2C object
  void *void_ptr = jerry_object_get_native_ptr (call_info_p->this_value, &native_obj_type_info);

  if (void_ptr == NULL)
  {
    return jerry_throw_sz (JERRY_ERROR_TYPE, "Failed to get native I2C pointer");
  }

  I2C *native_ptr = static_cast<I2C *> (void_ptr);

  native_ptr->start ();
  return jerry_undefined ();
}

/**
 * I2C#stop (native JavaScript method)
 *
 * Creates a stop condition on the I2C bus.
 */
DECLARE_CLASS_FUNCTION (I2C, stop)
{
  CHECK_ARGUMENT_COUNT (I2C, stop, (args_count == 0));

  // Extract native I2C object
  void *void_ptr = jerry_object_get_native_ptr (call_info_p->this_value, &native_obj_type_info);

  if (void_ptr == NULL)
  {
    return jerry_throw_sz (JERRY_ERROR_TYPE, "Failed to get native I2C pointer");
  }

  I2C *native_ptr = static_cast<I2C *> (void_ptr);

  native_ptr->stop ();
  return jerry_undefined ();
}

/**
 * I2C (native JavaScript constructor)
 *
 * @param sda mbed pin for I2C data
 * @param scl mbed pin for I2C clock
 * @returns a JavaScript object representing the I2C bus.
 */
DECLARE_CLASS_CONSTRUCTOR (I2C)
{
  CHECK_ARGUMENT_COUNT (I2C, __constructor, (args_count == 2));
  CHECK_ARGUMENT_TYPE_ALWAYS (I2C, __constructor, 0, number);
  CHECK_ARGUMENT_TYPE_ALWAYS (I2C, __constructor, 1, number);

  int sda = jerry_value_as_number (args[0]);
  int scl = jerry_value_as_number (args[1]);

  I2C *native_ptr = new I2C ((PinName) sda, (PinName) scl);

  jerry_value_t js_object = jerry_object ();
  jerry_object_set_native_ptr (js_object, &native_obj_type_info, native_ptr);

  ATTACH_CLASS_FUNCTION (js_object, I2C, frequency);
  ATTACH_CLASS_FUNCTION (js_object, I2C, read);
  ATTACH_CLASS_FUNCTION (js_object, I2C, write);
  ATTACH_CLASS_FUNCTION (js_object, I2C, start);
  ATTACH_CLASS_FUNCTION (js_object, I2C, stop);

  return js_object;
}