tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32L1/analogout_api.c

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2014, STMicroelectronics
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright notice,
   9  *    this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright notice,
  11  *    this list of conditions and the following disclaimer in the documentation
  12  *    and/or other materials provided with the distribution.
  13  * 3. Neither the name of STMicroelectronics nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  24  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28 #include "mbed_assert.h"
  29 #include "analogout_api.h"
  30
  31 #if DEVICE_ANALOGOUT
  32
  33 #include "cmsis.h"
  34 #include "pinmap.h"
  35 #include "mbed_error.h"
  36 #include "PeripheralPins.h"
  37
  38 #define DAC_RANGE (0xFFF) // 12 bits
  39
  40 static DAC_HandleTypeDef DacHandle;
  41
  42 // These variables are used for the "free" function
  43 static int pa4_used = 0;
  44 static int pa5_used = 0;
  45
  46 void analogout_init(dac_t *obj, PinName pin)
  47 {
  48     DAC_ChannelConfTypeDef sConfig;
  49
  50     DacHandle.Instance = DAC;
  51
  52     // Get the peripheral name (DAC_1, ...) from the pin and assign it to the object
  53     obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
  54     MBED_ASSERT(obj->dac != (DACName)NC);
  55
  56     // Configure GPIO
  57     pinmap_pinout(pin, PinMap_DAC);
  58
  59     // Save the channel for future use
  60     obj->pin = pin;
  61
  62     // Enable DAC clock
  63     __DAC_CLK_ENABLE();
  64
  65     // Configure DAC
  66     sConfig.DAC_Trigger      = DAC_TRIGGER_NONE;
  67     sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
  68
  69     if (pin == PA_4) {
  70         HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_1);
  71         pa4_used = 1;
  72     } else { // PA_5
  73         HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_2);
  74         pa5_used = 1;
  75     }
  76
  77     analogout_write_u16(obj, 0);
  78 }
  79
  80 void analogout_free(dac_t *obj)
  81 {
  82     // Reset DAC and disable clock
  83     if (obj->pin == PA_4) pa4_used = 0;
  84     if (obj->pin == PA_5) pa5_used = 0;
  85     if ((pa4_used == 0) && (pa5_used == 0)) {
  86         __DAC_FORCE_RESET();
  87         __DAC_RELEASE_RESET();
  88         __DAC_CLK_DISABLE();
  89     }
  90
  91     // Configure GPIO
  92     pin_function(obj->pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
  93 }
  94
  95 static inline void dac_write(dac_t *obj, uint16_t value)
  96 {
  97     if (obj->pin == PA_4) {
  98         HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_1, DAC_ALIGN_12B_R, value);
  99         HAL_DAC_Start(&DacHandle, DAC_CHANNEL_1);
 100     } else { // PA_5
 101         HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_2, DAC_ALIGN_12B_R, value);
 102         HAL_DAC_Start(&DacHandle, DAC_CHANNEL_2);
 103     }
 104 }
 105
 106 static inline int dac_read(dac_t *obj)
 107 {
 108     if (obj->pin == PA_4) {
 109         return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_1);
 110     } else { // PA_5
 111         return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_2);
 112     }
 113 }
 114
 115 void analogout_write(dac_t *obj, float value)
 116 {
 117     if (value < 0.0f) {
 118         dac_write(obj, 0); // Min value
 119     } else if (value > 1.0f) {
 120         dac_write(obj, (uint16_t)DAC_RANGE); // Max value
 121     } else {
 122         dac_write(obj, (uint16_t)(value * (float)DAC_RANGE));
 123     }
 124 }
 125
 126 void analogout_write_u16(dac_t *obj, uint16_t value)
 127 {
 128     if (value > (uint16_t)DAC_RANGE) {
 129         dac_write(obj, (uint16_t)DAC_RANGE); // Max value
 130     } else {
 131         dac_write(obj, value);
 132     }
 133 }
 134
 135 float analogout_read(dac_t *obj)
 136 {
 137     uint32_t value = dac_read(obj);
 138     return (float)((float)value * (1.0f / (float)DAC_RANGE));
 139 }
 140
 141 uint16_t analogout_read_u16(dac_t *obj)
 142 {
 143     return (uint16_t)dac_read(obj);
 144 }
 145
 146 #endif // DEVICE_ANALOGOUT