Umar Naeem / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by Umar Naeem

targets/TARGET_NXP/TARGET_LPC43XX/analogin_api.c@165:2dd56e6daeec, 2017-05-23 (annotated)

Committer:
ranaumarnaeem
Date:
Tue May 23 12:54:50 2017 +0000
Revision:
165:2dd56e6daeec
Parent:
149:156823d33999 
jhjg

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 *
<> 144:ef7eb2e8f9f7 16 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
<> 144:ef7eb2e8f9f7 17 */
<> 144:ef7eb2e8f9f7 18 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 19 #include "analogin_api.h"
<> 144:ef7eb2e8f9f7 20 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 21 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 22 #include "mbed_error.h"
<> 144:ef7eb2e8f9f7 23 #include "gpio_api.h"
<> 144:ef7eb2e8f9f7 24
<> 144:ef7eb2e8f9f7 25 #define ANALOGIN_MEDIAN_FILTER 1
<> 144:ef7eb2e8f9f7 26
<> 144:ef7eb2e8f9f7 27 static inline int div_round_up(int x, int y) {
<> 144:ef7eb2e8f9f7 28 return (x + (y - 1)) / y;
<> 144:ef7eb2e8f9f7 29 }
<> 144:ef7eb2e8f9f7 30
<> 144:ef7eb2e8f9f7 31 static const PinMap PinMap_ADC[] = {
<> 144:ef7eb2e8f9f7 32 {P4_3, ADC0_0, 0},
<> 144:ef7eb2e8f9f7 33 {P4_1, ADC0_1, 0},
<> 144:ef7eb2e8f9f7 34 {PF_8, ADC0_2, 0},
<> 144:ef7eb2e8f9f7 35 {P7_5, ADC0_3, 0},
<> 144:ef7eb2e8f9f7 36 {P7_4, ADC0_4, 0},
<> 144:ef7eb2e8f9f7 37 {PF_10, ADC0_5, 0},
<> 144:ef7eb2e8f9f7 38 {PB_6, ADC0_6, 0},
<> 144:ef7eb2e8f9f7 39 {PC_3, ADC1_0, 0},
<> 144:ef7eb2e8f9f7 40 {PC_0, ADC1_1, 0},
<> 144:ef7eb2e8f9f7 41 {PF_9, ADC1_2, 0},
<> 144:ef7eb2e8f9f7 42 {PF_6, ADC1_3, 0},
<> 144:ef7eb2e8f9f7 43 {PF_5, ADC1_4, 0},
<> 144:ef7eb2e8f9f7 44 {PF_11, ADC1_5, 0},
<> 144:ef7eb2e8f9f7 45 {P7_7, ADC1_6, 0},
<> 144:ef7eb2e8f9f7 46 {PF_7, ADC1_7, 0},
<> 148:21d94c44109e 47 {adc0_0, ADC_pin0_0, 0},
<> 148:21d94c44109e 48 {adc0_1, ADC_pin0_1, 0},
<> 148:21d94c44109e 49 {adc0_2, ADC_pin0_2, 0},
<> 148:21d94c44109e 50 {adc0_3, ADC_pin0_3, 0},
<> 148:21d94c44109e 51 {adc0_4, ADC_pin0_4, 0},
<> 148:21d94c44109e 52 {adc0_5, ADC_pin0_5, 0},
<> 148:21d94c44109e 53 {adc0_6, ADC_pin0_6, 0},
<> 148:21d94c44109e 54 {adc0_7, ADC_pin0_7, 0},
<> 148:21d94c44109e 55 {adc1_0, ADC_pin1_0, 0},
<> 148:21d94c44109e 56 {adc1_1, ADC_pin1_1, 0},
<> 148:21d94c44109e 57 {adc1_2, ADC_pin1_2, 0},
<> 148:21d94c44109e 58 {adc1_3, ADC_pin1_3, 0},
<> 148:21d94c44109e 59 {adc1_4, ADC_pin1_4, 0},
<> 148:21d94c44109e 60 {adc1_5, ADC_pin1_5, 0},
<> 148:21d94c44109e 61 {adc1_6, ADC_pin1_6, 0},
<> 148:21d94c44109e 62 {adc1_7, ADC_pin1_7, 0},
<> 144:ef7eb2e8f9f7 63 {NC, NC, 0 }
<> 144:ef7eb2e8f9f7 64 };
<> 144:ef7eb2e8f9f7 65
<> 144:ef7eb2e8f9f7 66 void analogin_init(analogin_t *obj, PinName pin) {
<> 144:ef7eb2e8f9f7 67 ADCName name;
<> 144:ef7eb2e8f9f7 68
<> 144:ef7eb2e8f9f7 69 name = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
<> 144:ef7eb2e8f9f7 70 MBED_ASSERT(obj->adc != (LPC_ADC_T *)NC);
<> 148:21d94c44109e 71
<> 148:21d94c44109e 72 // Set ADC number
<> 148:21d94c44109e 73 if(name < ADC1_0) {
<> 148:21d94c44109e 74 obj->num = 0;
<> 148:21d94c44109e 75 } else if(name < ADC_pin0_0 && name > ADC0_6) {
<> 148:21d94c44109e 76 obj->num = 1;
<> 148:21d94c44109e 77 } else if(name < ADC_pin1_1 && name > ADC1_7) {
<> 148:21d94c44109e 78 obj->num = 0;
<> 148:21d94c44109e 79 } else if(name > ADC_pin0_7) {
<> 148:21d94c44109e 80 obj->num = 1;
<> 148:21d94c44109e 81 }
<> 144:ef7eb2e8f9f7 82
<> 148:21d94c44109e 83 //ADC register and channel
<> 144:ef7eb2e8f9f7 84 obj->ch = name % (ADC0_7 + 1);
<> 144:ef7eb2e8f9f7 85 obj->adc = (LPC_ADC_T *) (obj->num > 0) ? LPC_ADC1 : LPC_ADC0;
<> 144:ef7eb2e8f9f7 86
<> 148:21d94c44109e 87 // Reset pin function to GPIO if it is a GPIO pin. for adc only pins it is not necessary
<> 148:21d94c44109e 88 if(name < ADC_pin0_0) {
<> 148:21d94c44109e 89 gpio_set(pin);
<> 148:21d94c44109e 90 // Select ADC on analog function select register in SCU
<> 148:21d94c44109e 91 LPC_SCU->ENAIO[obj->num] |= (1 << obj->ch);
<> 148:21d94c44109e 92 } else {
<> 148:21d94c44109e 93 LPC_SCU->ENAIO[obj->num] &= ~(1 << obj->ch);
<> 148:21d94c44109e 94 }
<> 144:ef7eb2e8f9f7 95
<> 144:ef7eb2e8f9f7 96 // Calculate minimum clock divider
<> 144:ef7eb2e8f9f7 97 // clkdiv = divider - 1
<> 144:ef7eb2e8f9f7 98 uint32_t PCLK = SystemCoreClock;
<> 144:ef7eb2e8f9f7 99 uint32_t adcRate = 400000;
<> 144:ef7eb2e8f9f7 100 uint32_t clkdiv = div_round_up(PCLK, adcRate) - 1;
<> 144:ef7eb2e8f9f7 101
<> 144:ef7eb2e8f9f7 102 // Set the generic software-controlled ADC settings
<> 144:ef7eb2e8f9f7 103 obj->adc->CR = (0 << 0) // SEL: 0 = no channels selected
<> 144:ef7eb2e8f9f7 104 | (clkdiv << 8) // CLKDIV:
<> 144:ef7eb2e8f9f7 105 | (0 << 16) // BURST: 0 = software control
<> 144:ef7eb2e8f9f7 106 | (1 << 21) // PDN: 1 = operational
<> 144:ef7eb2e8f9f7 107 | (0 << 24) // START: 0 = no start
<> 144:ef7eb2e8f9f7 108 | (0 << 27); // EDGE: not applicable
<> 144:ef7eb2e8f9f7 109 }
<> 144:ef7eb2e8f9f7 110
<> 144:ef7eb2e8f9f7 111 static inline uint32_t adc_read(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 112 uint32_t temp;
<> 144:ef7eb2e8f9f7 113 uint8_t channel = obj->ch;
<> 144:ef7eb2e8f9f7 114 LPC_ADC_T *pADC = obj->adc;
<> 144:ef7eb2e8f9f7 115
<> 144:ef7eb2e8f9f7 116 // Select the appropriate channel and start conversion
<> 144:ef7eb2e8f9f7 117 pADC->CR |= ADC_CR_CH_SEL(channel);
<> 144:ef7eb2e8f9f7 118 temp = pADC->CR & ~ADC_CR_START_MASK;
<> 144:ef7eb2e8f9f7 119 pADC->CR = temp | (ADC_CR_START_MODE_SEL(ADC_START_NOW));
<> 144:ef7eb2e8f9f7 120
<> 144:ef7eb2e8f9f7 121 // Wait for DONE bit and read data
<> 144:ef7eb2e8f9f7 122 while (!(pADC->STAT & ADC_CR_CH_SEL(channel)));
<> 144:ef7eb2e8f9f7 123 temp = pADC->DR[channel];
<> 144:ef7eb2e8f9f7 124
<> 144:ef7eb2e8f9f7 125 // Deselect channel and return result
<> 144:ef7eb2e8f9f7 126 pADC->CR &= ~ADC_CR_START_MASK;
<> 144:ef7eb2e8f9f7 127 pADC->CR &= ~ADC_CR_CH_SEL(channel);
<> 144:ef7eb2e8f9f7 128 return ADC_DR_RESULT(temp);
<> 144:ef7eb2e8f9f7 129 }
<> 144:ef7eb2e8f9f7 130
<> 144:ef7eb2e8f9f7 131 static inline void order(uint32_t *a, uint32_t *b) {
<> 144:ef7eb2e8f9f7 132 if (*a > *b) {
<> 144:ef7eb2e8f9f7 133 uint32_t t = *a;
<> 144:ef7eb2e8f9f7 134 *a = *b;
<> 144:ef7eb2e8f9f7 135 *b = t;
<> 144:ef7eb2e8f9f7 136 }
<> 144:ef7eb2e8f9f7 137 }
<> 144:ef7eb2e8f9f7 138
<> 144:ef7eb2e8f9f7 139 static inline uint32_t adc_read_u32(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 140 uint32_t value;
<> 144:ef7eb2e8f9f7 141 #if ANALOGIN_MEDIAN_FILTER
<> 144:ef7eb2e8f9f7 142 uint32_t v1 = adc_read(obj);
<> 144:ef7eb2e8f9f7 143 uint32_t v2 = adc_read(obj);
<> 144:ef7eb2e8f9f7 144 uint32_t v3 = adc_read(obj);
<> 144:ef7eb2e8f9f7 145 order(&v1, &v2);
<> 144:ef7eb2e8f9f7 146 order(&v2, &v3);
<> 144:ef7eb2e8f9f7 147 order(&v1, &v2);
<> 144:ef7eb2e8f9f7 148 value = v2;
<> 144:ef7eb2e8f9f7 149 #else
<> 144:ef7eb2e8f9f7 150 value = adc_read(obj);
<> 144:ef7eb2e8f9f7 151 #endif
<> 144:ef7eb2e8f9f7 152 return value;
<> 144:ef7eb2e8f9f7 153 }
<> 144:ef7eb2e8f9f7 154
<> 144:ef7eb2e8f9f7 155 uint16_t analogin_read_u16(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 156 uint32_t value = adc_read_u32(obj);
<> 144:ef7eb2e8f9f7 157
<> 144:ef7eb2e8f9f7 158 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
<> 144:ef7eb2e8f9f7 159 }
<> 144:ef7eb2e8f9f7 160
<> 144:ef7eb2e8f9f7 161 float analogin_read(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 162 uint32_t value = adc_read_u32(obj);
<> 144:ef7eb2e8f9f7 163 return (float)value * (1.0f / (float)ADC_RANGE);
<> 144:ef7eb2e8f9f7 164 }