tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_K20XX/analogout_api.c

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2015 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
  17 #include "mbed_assert.h"
  18 #include "analogout_api.h"
  19
  20 #if DEVICE_ANALOGOUT
  21
  22 #include "cmsis.h"
  23 #include "pinmap.h"
  24 #include "PeripheralPins.h"
  25
  26 #define RANGE_12BIT     0xFFF
  27
  28 void analogout_init(dac_t *obj, PinName pin) {
  29     obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
  30     MBED_ASSERT(obj->dac != (DACName)NC);
  31
  32     SIM->SCGC2 |= SIM_SCGC2_DAC0_MASK;
  33
  34     uint32_t port = (uint32_t)pin >> PORT_SHIFT;
  35     SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
  36
  37     DAC0->DAT[obj->dac].DATH = 0;
  38     DAC0->DAT[obj->dac].DATL = 0;
  39
  40     DAC0->C1 = DAC_C1_DACBFMD_MASK;     // One-Time Scan Mode
  41
  42     DAC0->C0 = DAC_C0_DACEN_MASK      // Enable
  43              | DAC_C0_DACSWTRG_MASK   // Software Trigger
  44              | DAC_C0_DACRFS_MASK;    // VDDA selected
  45
  46     analogout_write_u16(obj, 0);
  47 }
  48
  49 void analogout_free(dac_t *obj) {}
  50
  51 static inline void dac_write(dac_t *obj, int value) {
  52     DAC0->DAT[obj->dac].DATL = (uint8_t)( value       & 0xFF);
  53     DAC0->DAT[obj->dac].DATH = (uint8_t)((value >> 8) & 0xFF);
  54 }
  55
  56 static inline int dac_read(dac_t *obj) {
  57     return ((DAC0->DAT[obj->dac].DATH << 8) | DAC0->DAT[obj->dac].DATL);
  58 }
  59
  60 void analogout_write(dac_t *obj, float value) {
  61     if (value < 0.0) {
  62         dac_write(obj, 0);
  63     } else if (value > 1.0) {
  64         dac_write(obj, RANGE_12BIT);
  65     } else {
  66         dac_write(obj, value * (float)RANGE_12BIT);
  67     }
  68 }
  69
  70 void analogout_write_u16(dac_t *obj, uint16_t value) {
  71     dac_write(obj, value >> 4); // 12-bit
  72 }
  73
  74 float analogout_read(dac_t *obj) {
  75     uint32_t value = dac_read(obj);
  76     return (float)value * (1.0f / (float)RANGE_12BIT);
  77 }
  78
  79 uint16_t analogout_read_u16(dac_t *obj) {
  80     uint32_t value = dac_read(obj); // 12-bit
  81     return (value << 4) | ((value >> 8) & 0x003F);
  82 }
  83
  84 #endif