aout.cpp

00001 /***************************************************************************//**
00002  *   @file   aout.cpp
00003  *   @brief  Implementation of mbed specific analog output functionality
00004 ********************************************************************************
00005  * Copyright (c) 2021 Analog Devices, Inc.
00006  * All rights reserved.
00007  *
00008  * This software is proprietary to Analog Devices, Inc. and its licensors.
00009  * By using this software you agree to the terms of the associated
00010  * Analog Devices Software License Agreement.
00011 *******************************************************************************/
00012 
00013 /******************************************************************************/
00014 /***************************** Include Files **********************************/
00015 /******************************************************************************/
00016 #include <mbed.h>
00017 
00018 // Platform drivers needs to be C-compatible to work with other drivers
00019 #ifdef __cplusplus
00020 extern "C"
00021 {
00022 #endif //  _cplusplus
00023 #include "aout.h "
00024 #include "mbed_ain_aout_extra.h"
00025 #include "error.h"
00026 
00027 /******************************************************************************/
00028 /********************** Variables and User defined data types *****************/
00029 /******************************************************************************/
00030 
00031 /******************************************************************************/
00032 /************************ Functions Declarations ******************************/
00033 /******************************************************************************/
00034 
00035 /******************************************************************************/
00036 /************************ Functions Definitions *******************************/
00037 /******************************************************************************/
00038 /**
00039  * @brief Write voltage to analog output pin
00040  * @param desc[in] - Analog output descriptor
00041  * @param value[in] - Analog output value in volts
00042  * @return SUCCESS in case of success, FAILURE otherwise.
00043  */
00044 int32_t aout_set_voltage(struct aout_desc *desc, float value)
00045 {
00046     /* Pointer to analog output object */
00047     mbed::AnalogOut *analog_output;
00048     float volt_mapped;
00049 
00050     /* Mbed AnalogOut APIs accept voltage in range from 0.0f
00051      * (representing DAC min output range / 0%) to 1.0f (representing
00052      * DAC max output range / 100%). Hence we need to map the voltage levels
00053      * before passing it to mbed APIs */
00054     if (value >= desc->aout_min_v && value <= desc->aout_max_v) {
00055         volt_mapped = ((value - desc->aout_min_v) /
00056                    (desc->aout_max_v - desc->aout_min_v));
00057     } else {
00058         return -EINVAL;
00059     }
00060 
00061     if (desc && desc->extra) {
00062         analog_output = (AnalogOut *)((mbed_analog_out_desc *)
00063                           desc->extra)->analog_out_obj ;
00064         analog_output->write(volt_mapped);
00065 
00066         return SUCCESS;
00067     }
00068     return FAILURE;
00069 }
00070 
00071 /**
00072  * @brief Initialize the analog output pin
00073  * @param desc[in, out] - Analog output descriptor structure
00074  * @param param[in] - Structure that contains analog output
00075  *                    initialization parameters
00076  * @return SUCCESS in case of success, FAILURE otherwise
00077  */
00078 int32_t aout_init(struct aout_desc **desc,
00079           const struct aout_init_param *param)
00080 {
00081     mbed::AnalogOut *analog_output;
00082     struct aout_desc *new_analog_out_desc;
00083     struct mbed_analog_out_desc *new_mbed_analog_out_desc;
00084 
00085     if (!desc || !param ) {
00086         return FAILURE;
00087     }
00088 
00089     /* Allocate memory for general analog output descriptor */
00090     new_analog_out_desc = (aout_desc *)malloc(sizeof(aout_desc));
00091     if (!new_analog_out_desc) {
00092         goto err_new_out_desc;
00093     }
00094 
00095     /* Configure pin number,DAC max and min range */
00096     new_analog_out_desc->number = param->number;
00097     new_analog_out_desc->aout_min_v = param->aout_min_v;
00098     new_analog_out_desc->aout_max_v = param->aout_max_v;
00099 
00100     /* Allocate memory for mbed specific analog output descriptor
00101      * for future use */
00102     new_mbed_analog_out_desc = (mbed_analog_out_desc *)malloc
00103                    (sizeof(new_mbed_analog_out_desc));
00104     if (!new_mbed_analog_out_desc) {
00105         goto err_mbed_analog_out_desc;
00106     }
00107 
00108     /* Create and initialize mbed analog output object */
00109     analog_output = new AnalogOut((PinName)param->number);
00110     if (analog_output) {
00111         new_mbed_analog_out_desc->analog_out_obj = analog_output;
00112     } else {
00113         goto err_analog_out_instance;
00114     }
00115 
00116     new_analog_out_desc->extra = (mbed_analog_out_desc *)
00117                      new_mbed_analog_out_desc;
00118 
00119     *desc = new_analog_out_desc;
00120     return SUCCESS;
00121 
00122 err_analog_out_instance:
00123     free(new_mbed_analog_out_desc);
00124 err_mbed_analog_out_desc:
00125     free(new_analog_out_desc);
00126 err_new_out_desc:
00127     // Nothing to free
00128 
00129     return FAILURE;
00130 }
00131 
00132 /**
00133  * @brief Deallocate resources allocated by aout_init()
00134  * @param desc[in, out] - Analog output descriptor
00135  * @return SUCCESS in case of success, FAILURE otherwise.
00136  */
00137 int32_t aout_remove(struct aout_desc *desc)
00138 {
00139     if (desc) {
00140 
00141         if (((mbed_analog_out_desc *)desc->extra)->analog_out_obj) {
00142             delete((mbed::AnalogIn *)((mbed_analog_out_desc *)desc->
00143                           extra)->analog_out_obj);
00144         }
00145 
00146         if ((mbed_analog_out_desc *)desc->extra) {
00147             free((mbed_analog_out_desc *)desc->extra);
00148         }
00149 
00150         if (((mbed_analog_out_desc *)desc->extra)->analog_out_obj) {
00151             delete((mbed::AnalogOut *)((mbed_analog_out_desc *)
00152                            desc->extra)->analog_out_obj);
00153         }
00154 
00155         if ((mbed_analog_out_desc *)desc->extra) {
00156             free((mbed_analog_out_desc *)desc->extra);
00157         }
00158 
00159         free(desc);
00160 
00161         return SUCCESS;
00162     }
00163 
00164     return FAILURE;
00165 }
00166 
00167 /**
00168  * @brief Mbed specific analog output platform ops structure
00169  */
00170 const struct aout_platform_ops mbed_aout_ops = {
00171     .init = &aout_init,
00172     .write = &aout_set_voltage,
00173     .remove = &aout_remove
00174 };
00175 
00176 
00177 // Platform drivers needs to be C-compatible to work with other drivers
00178 #ifdef __cplusplus
00179 }
00180 #endif //  _cplusplus