text: /*
  Copyright (c) 2013 Ben Croston
  
  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 "Python.h"
  #include "soft_pwm.h"
  #include "py_pwm.h"
  #include "common.h"
  #include "c_gpio.h"
  
  typedef struct
  {
      PyObject_HEAD
      unsigned int gpio;
      float freq;
      float dutycycle;
  } PWMObject;
  
  // python method PWM.__init__(self, channel, frequency)
  static int PWM_init(PWMObject *self, PyObject *args, PyObject *kwds)
  {
      int channel;
      float frequency;
  
      if (!PyArg_ParseTuple(args, "if", &channel, &frequency))
          return -1;
  
      // convert channel to gpio
      if (get_gpio_number(channel, &(self->gpio)))
          return -1;
  
      // ensure channel set as output
      if (gpio_direction[self->gpio] != OUTPUT)
      {
          PyErr_SetString(PyExc_RuntimeError, "You must setup() the GPIO channel as an output first");
          return -1;
      }
  
      if (frequency <= 0.0)
      {
          PyErr_SetString(PyExc_ValueError, "frequency must be greater than 0.0");
          return -1;
      }
  
      self->freq = frequency;
  
      //!!!Original odroid port passed rpi BCM number. Now passing native GPIO number to pwm_set_frequency
      pwm_set_frequency(self->gpio, self->freq);
      return 0;
  }
  
  // python method PWM.start(self, dutycycle)
  static PyObject *PWM_start(PWMObject *self, PyObject *args)
  {
      float dutycycle;
  
      if (!PyArg_ParseTuple(args, "f", &dutycycle))
          return NULL;
  
      if (dutycycle < 0.0 || dutycycle > 100.0)
      {
          PyErr_SetString(PyExc_ValueError, "dutycycle must have a value from 0.0 to 100.0");
          return NULL;
      }
  
      self->dutycycle = dutycycle;
      pwm_set_duty_cycle(self->gpio, self->dutycycle);
      pwm_start(self->gpio);
      Py_RETURN_NONE;
  }
  
  // python method PWM.ChangeDutyCycle(self, dutycycle)
  static PyObject *PWM_ChangeDutyCycle(PWMObject *self, PyObject *args)
  {
      float dutycycle = 0.0;
      if (!PyArg_ParseTuple(args, "f", &dutycycle))
          return NULL;
  
      if (dutycycle < 0.0 || dutycycle > 100.0)
      {
          PyErr_SetString(PyExc_ValueError, "dutycycle must have a value from 0.0 to 100.0");
          return NULL;
      }
  
      self->dutycycle = dutycycle;
      pwm_set_duty_cycle(self->gpio, self->dutycycle);
      Py_RETURN_NONE;
  }
  
  // python method PWM. ChangeFrequency(self, frequency)
  static PyObject *PWM_ChangeFrequency(PWMObject *self, PyObject *args)
  {
      float frequency = 1.0;
  
      if (!PyArg_ParseTuple(args, "f", &frequency))
          return NULL;
  
      if (frequency <= 0.0)
      {
          PyErr_SetString(PyExc_ValueError, "frequency must be greater than 0.0");
          return NULL;
      }
  
      self->freq = frequency;
  
      pwm_set_frequency(self->gpio, self->freq);
      Py_RETURN_NONE;
  }
  
  // python function PWM.stop(self)
  static PyObject *PWM_stop(PWMObject *self, PyObject *args)
  {
      pwm_stop(self->gpio);
      Py_RETURN_NONE;
  }
  
  // deallocation method
  static void PWM_dealloc(PWMObject *self)
  {
      pwm_stop(self->gpio);
      Py_TYPE(self)->tp_free((PyObject*)self);
  }
  
  static PyMethodDef
  PWM_methods[] = {
     { "start", (PyCFunction)PWM_start, METH_VARARGS, "Start software PWM\ndutycycle - the duty cycle (0.0 to 100.0)" },
     { "ChangeDutyCycle", (PyCFunction)PWM_ChangeDutyCycle, METH_VARARGS, "Change the duty cycle\ndutycycle - between 0.0 and 100.0" },
     { "ChangeFrequency", (PyCFunction)PWM_ChangeFrequency, METH_VARARGS, "Change the frequency\nfrequency - frequency in Hz (freq > 1.0)" },
     { "stop", (PyCFunction)PWM_stop, METH_VARARGS, "Stop software PWM" },
     { NULL }
  };
  
  PyTypeObject PWMType = {
     PyVarObject_HEAD_INIT(NULL,0)
     "RPi.GPIO.PWM",            // tp_name
     sizeof(PWMObject),         // tp_basicsize
     0,                         // tp_itemsize
     (destructor)PWM_dealloc,   // tp_dealloc
     0,                         // tp_print
     0,                         // tp_getattr
     0,                         // tp_setattr
     0,                         // tp_compare
     0,                         // tp_repr
     0,                         // tp_as_number
     0,                         // tp_as_sequence
     0,                         // tp_as_mapping
     0,                         // tp_hash
     0,                         // tp_call
     0,                         // tp_str
     0,                         // tp_getattro
     0,                         // tp_setattro
     0,                         // tp_as_buffer
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, // tp_flag
     "Pulse Width Modulation class",    // tp_doc
     0,                         // tp_traverse
     0,                         // tp_clear
     0,                         // tp_richcompare
     0,                         // tp_weaklistoffset
     0,                         // tp_iter
     0,                         // tp_iternext
     PWM_methods,               // tp_methods
     0,                         // tp_members
     0,                         // tp_getset
     0,                         // tp_base
     0,                         // tp_dict
     0,                         // tp_descr_get
     0,                         // tp_descr_set
     0,                         // tp_dictoffset
     (initproc)PWM_init,        // tp_init
     0,                         // tp_alloc
     0,                         // tp_new
  };
  
  PyTypeObject *PWM_init_PWMType(void)
  {
     // Fill in some slots in the type, and make it ready
     PWMType.tp_new = PyType_GenericNew;
     if (PyType_Ready(&PWMType) < 0)
        return NULL;
  
     return &PWMType;
  }
  