tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32L0/analogin_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 "analogin_api.h"
  30
  31 #if DEVICE_ANALOGIN
  32
  33 #include "wait_api.h"
  34 #include "cmsis.h"
  35 #include "pinmap.h"
  36 #include "PeripheralPins.h"
  37
  38 ADC_HandleTypeDef AdcHandle;
  39
  40 int adc_inited = 0;
  41
  42 void analogin_init(analogin_t *obj, PinName pin)
  43 {
  44     // Get the peripheral name from the pin and assign it to the object
  45     obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
  46     MBED_ASSERT(obj->adc != (ADCName)NC);
  47
  48     // Configure GPIO
  49     pinmap_pinout(pin, PinMap_ADC);
  50
  51     // Save pin number for the read function
  52     obj->pin = pin;
  53
  54     // The ADC initialization is done once
  55     if (adc_inited == 0) {
  56         adc_inited = 1;
  57
  58         AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);
  59
  60         // Enable ADC clock
  61         __ADC1_CLK_ENABLE();
  62
  63         // Configure ADC
  64         AdcHandle.Init.OversamplingMode      = DISABLE;
  65         AdcHandle.Init.ClockPrescaler        = ADC_CLOCKPRESCALER_PCLK_DIV1;
  66         AdcHandle.Init.Resolution            = ADC_RESOLUTION12b;
  67         AdcHandle.Init.SamplingTime          = ADC_SAMPLETIME_41CYCLES_5;
  68         AdcHandle.Init.ScanConvMode          = ADC_SCAN_DIRECTION_FORWARD;
  69         AdcHandle.Init.DataAlign             = ADC_DATAALIGN_RIGHT;
  70         AdcHandle.Init.ContinuousConvMode    = DISABLE;
  71         AdcHandle.Init.DiscontinuousConvMode = DISABLE;
  72         AdcHandle.Init.ExternalTrigConvEdge  = ADC_EXTERNALTRIG_EDGE_NONE;
  73         AdcHandle.Init.ExternalTrigConv      = ADC_EXTERNALTRIG0_T6_TRGO; // Not used here
  74         AdcHandle.Init.DMAContinuousRequests = DISABLE;
  75         AdcHandle.Init.EOCSelection          = EOC_SINGLE_CONV;
  76         AdcHandle.Init.Overrun               = OVR_DATA_OVERWRITTEN;
  77         AdcHandle.Init.LowPowerAutoWait      = ENABLE;
  78         AdcHandle.Init.LowPowerFrequencyMode = DISABLE; // To be enabled only if ADC clock < 2.8 MHz
  79         AdcHandle.Init.LowPowerAutoPowerOff  = DISABLE;
  80         HAL_ADC_Init(&AdcHandle);
  81
  82         // Calibration
  83         HAL_ADCEx_Calibration_Start(&AdcHandle, ADC_SINGLE_ENDED);
  84
  85         __HAL_ADC_ENABLE(&AdcHandle);
  86     }
  87 }
  88
  89 static inline uint16_t adc_read(analogin_t *obj)
  90 {
  91     ADC_ChannelConfTypeDef sConfig;
  92
  93     AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);
  94
  95     // Configure ADC channel
  96     switch (obj->pin) {
  97         case PA_0:
  98             sConfig.Channel = ADC_CHANNEL_0;
  99             break;
 100         case PA_1:
 101             sConfig.Channel = ADC_CHANNEL_1;
 102             break;
 103         case PA_2:
 104             sConfig.Channel = ADC_CHANNEL_2;
 105             break;
 106         case PA_3:
 107             sConfig.Channel = ADC_CHANNEL_3;
 108             break;
 109         case PA_4:
 110             sConfig.Channel = ADC_CHANNEL_4;
 111             break;
 112         case PA_5:
 113             sConfig.Channel = ADC_CHANNEL_5;
 114             break;
 115         case PA_6:
 116             sConfig.Channel = ADC_CHANNEL_6;
 117             break;
 118         case PA_7:
 119             sConfig.Channel = ADC_CHANNEL_7;
 120             break;
 121         case PB_0:
 122             sConfig.Channel = ADC_CHANNEL_8;
 123             break;
 124         case PB_1:
 125             sConfig.Channel = ADC_CHANNEL_9;
 126             break;
 127         case PC_0:
 128             sConfig.Channel = ADC_CHANNEL_10;
 129             break;
 130         case PC_1:
 131             sConfig.Channel = ADC_CHANNEL_11;
 132             break;
 133         case PC_2:
 134             sConfig.Channel = ADC_CHANNEL_12;
 135             break;
 136         case PC_3:
 137             sConfig.Channel = ADC_CHANNEL_13;
 138             break;
 139         case PC_4:
 140             sConfig.Channel = ADC_CHANNEL_14;
 141             break;
 142         case PC_5:
 143             sConfig.Channel = ADC_CHANNEL_15;
 144             break;
 145         default:
 146             return 0;
 147     }
 148
 149     ADC1->CHSELR = 0; // [TODO] Workaround. To be removed after Cube driver is corrected.
 150     HAL_ADC_ConfigChannel(&AdcHandle, &sConfig);
 151
 152     HAL_ADC_Start(&AdcHandle); // Start conversion
 153
 154     // Wait end of conversion and get value
 155     if (HAL_ADC_PollForConversion(&AdcHandle, 10) == HAL_OK) {
 156         return (HAL_ADC_GetValue(&AdcHandle));
 157     } else {
 158         return 0;
 159     }
 160 }
 161
 162 uint16_t analogin_read_u16(analogin_t *obj)
 163 {
 164     uint16_t value = adc_read(obj);
 165     // 12-bit to 16-bit conversion
 166     value = ((value << 4) & (uint16_t)0xFFF0) | ((value >> 8) & (uint16_t)0x000F);
 167     return value;
 168 }
 169
 170 float analogin_read(analogin_t *obj)
 171 {
 172     uint16_t value = adc_read(obj);
 173     return (float)value * (1.0f / (float)0xFFF); // 12 bits range
 174 }
 175
 176 #endif