tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KPSDK_MCUS/analogin_api.c

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2013 ARM Limited
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 #include "mbed_assert.h"
  17 #include "analogin_api.h"
  18
  19 #if DEVICE_ANALOGIN
  20
  21 #include "cmsis.h"
  22 #include "pinmap.h"
  23 #include "PeripheralNames.h"
  24 #include "fsl_adc_hal.h"
  25 #include "fsl_clock_manager.h"
  26 #include "PeripheralPins.h"
  27 #include "fsl_device_registers.h"
  28
  29 #define MAX_FADC 6000000
  30
  31 void analogin_init(analogin_t *obj, PinName pin) {
  32     obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
  33     MBED_ASSERT(obj->adc != (ADCName)NC);
  34
  35     uint32_t instance = obj->adc >> ADC_INSTANCE_SHIFT;
  36     uint32_t adc_addrs[] = ADC_BASE_ADDRS;
  37
  38     CLOCK_SYS_EnableAdcClock(instance);
  39
  40     uint32_t bus_clock;
  41     CLOCK_SYS_GetFreq(kBusClock, &bus_clock);
  42     uint32_t clkdiv;
  43     for (clkdiv = 0; clkdiv < 4; clkdiv++) {
  44         if ((bus_clock >> clkdiv) <= MAX_FADC)
  45             break;
  46     }
  47     if (clkdiv == 4) {
  48         clkdiv = 0x3; //Set max div
  49     }
  50     /* adc is enabled/triggered when reading. */
  51     ADC_HAL_Init(adc_addrs[instance]);
  52     ADC_HAL_SetClkSrcMode(adc_addrs[instance], kAdcClkSrcOfBusClk);
  53     ADC_HAL_SetClkDividerMode(adc_addrs[instance], (adc_clk_divider_mode_t)(clkdiv & 0x3));
  54     ADC_HAL_SetRefVoltSrcMode(adc_addrs[instance], kAdcRefVoltSrcOfVref);
  55     ADC_HAL_SetResolutionMode(adc_addrs[instance], kAdcResolutionBitOfSingleEndAs16);
  56     ADC_HAL_SetContinuousConvCmd(adc_addrs[instance], false);
  57     ADC_HAL_SetHwTriggerCmd(adc_addrs[instance], false); /* sw trigger */
  58     ADC_HAL_SetHwAverageCmd(adc_addrs[instance], true);
  59     ADC_HAL_SetHwAverageMode(adc_addrs[instance], kAdcHwAverageCountOf4);
  60     ADC_HAL_SetChnMuxMode(adc_addrs[instance], kAdcChnMuxOfB); /* only B channels are avail */
  61
  62     pinmap_pinout(pin, PinMap_ADC);
  63 }
  64
  65 uint16_t analogin_read_u16(analogin_t *obj) {
  66     uint32_t instance = obj->adc >> ADC_INSTANCE_SHIFT;
  67     uint32_t adc_addrs[] = ADC_BASE_ADDRS;
  68     /* sw trigger (SC1A) */
  69     ADC_HAL_ConfigChn(adc_addrs[instance], 0, false, false, obj->adc & 0xF);
  70     while (!ADC_HAL_GetChnConvCompletedCmd(adc_addrs[instance], 0));
  71     return ADC_HAL_GetChnConvValueRAW(adc_addrs[instance], 0);
  72 }
  73
  74 float analogin_read(analogin_t *obj) {
  75     uint16_t value = analogin_read_u16(obj);
  76     return (float)value * (1.0f / (float)0xFFFF);
  77 }
  78
  79 #endif