mirror of https://github.com/ARMmbed/mbed-os.git
95 lines
3.1 KiB
C
95 lines
3.1 KiB
C
/* mbed Microcontroller Library
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* Copyright (c) 2006-2013 ARM Limited
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "mbed_assert.h"
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#include "analogin_api.h"
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#if DEVICE_ANALOGIN
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#include "cmsis.h"
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#include "pinmap.h"
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#include "PeripheralNames.h"
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#include "fsl_adc16.h"
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#include "PeripheralPins.h"
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/* Array of ADC peripheral base address. */
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static ADC_Type *const adc_addrs[] = ADC_BASE_PTRS;
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#define MAX_FADC 6000000
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void analogin_init(analogin_t *obj, PinName pin)
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{
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obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
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MBED_ASSERT(obj->adc != (ADCName)NC);
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uint32_t instance = obj->adc >> ADC_INSTANCE_SHIFT;
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uint32_t bus_clock;
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adc16_config_t adc16_config;
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bus_clock = CLOCK_GetFreq(kCLOCK_BusClk);
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uint32_t clkdiv;
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for (clkdiv = 0; clkdiv < 4; clkdiv++) {
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if ((bus_clock >> clkdiv) <= MAX_FADC)
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break;
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}
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if (clkdiv == 4) {
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clkdiv = 0x3; //Set max div
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}
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ADC16_GetDefaultConfig(&adc16_config);
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adc16_config.clockSource = kADC16_ClockSourceAlt0;
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adc16_config.clockDivider = (adc16_clock_divider_t)clkdiv;
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adc16_config.resolution = kADC16_ResolutionSE16Bit;
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ADC16_Init(adc_addrs[instance], &adc16_config);
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ADC16_EnableHardwareTrigger(adc_addrs[instance], false);
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ADC16_SetHardwareAverage(adc_addrs[instance], kADC16_HardwareAverageCount4);
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pinmap_pinout(pin, PinMap_ADC);
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}
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uint16_t analogin_read_u16(analogin_t *obj)
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{
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uint32_t instance = obj->adc >> ADC_INSTANCE_SHIFT;
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adc16_channel_config_t adc16_channel_config;
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adc16_channel_config.channelNumber = obj->adc & 0xF;
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adc16_channel_config.enableInterruptOnConversionCompleted = false;
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#if defined(FSL_FEATURE_ADC16_HAS_DIFF_MODE) && FSL_FEATURE_ADC16_HAS_DIFF_MODE
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adc16_channel_config.enableDifferentialConversion = false;
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#endif
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ADC16_SetChannelMuxMode(adc_addrs[instance],
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obj->adc & (1 << ADC_B_CHANNEL_SHIFT) ? kADC16_ChannelMuxB : kADC16_ChannelMuxA);
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/*
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* When in software trigger mode, each conversion would be launched once calling the "ADC16_ChannelConfigure()"
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* function, which works like writing a conversion command and executing it.
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*/
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ADC16_SetChannelConfig(adc_addrs[instance], 0, &adc16_channel_config);
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while (0U == (kADC16_ChannelConversionDoneFlag &
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ADC16_GetChannelStatusFlags(adc_addrs[instance], 0)))
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{
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}
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return ADC16_GetChannelConversionValue(adc_addrs[instance], 0);
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}
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float analogin_read(analogin_t *obj)
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{
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uint16_t value = analogin_read_u16(obj);
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return (float)value * (1.0f / (float)0xFFFF);
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}
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#endif
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