mirror of https://github.com/ARMmbed/mbed-os.git
144 lines
4.3 KiB
C
144 lines
4.3 KiB
C
/***************************************************************************//**
|
|
* @file analogout_aoi.c
|
|
*******************************************************************************
|
|
* @section License
|
|
* <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b>
|
|
*******************************************************************************
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
* not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
******************************************************************************/
|
|
|
|
#include "device.h"
|
|
#if DEVICE_ANALOGOUT
|
|
|
|
#include "mbed_assert.h"
|
|
#include "mbed_error.h"
|
|
#include "analogout_api.h"
|
|
#include "pinmap.h"
|
|
#include "pinmap_function.h"
|
|
#include "PeripheralPins.h"
|
|
#include "clocking.h"
|
|
|
|
#include "em_dac.h"
|
|
#include "em_cmu.h"
|
|
|
|
static uint8_t dac_initialized = 0;
|
|
|
|
void analogout_init(dac_t *obj, PinName pin)
|
|
{
|
|
/* init in-memory structure */
|
|
obj->dac = (DAC_TypeDef *) pinmap_peripheral(pin, PinMap_DAC);
|
|
MBED_ASSERT((int) obj->dac != NC);
|
|
|
|
obj->channel = pin_location(pin, PinMap_DAC);
|
|
MBED_ASSERT((int) obj->channel != NC);
|
|
|
|
pin_mode(pin, Disabled);
|
|
|
|
if (!dac_initialized) {
|
|
/* Initialize the DAC. Will disable both DAC channels, so should only be done once */
|
|
/* Use default settings */
|
|
CMU_ClockEnable(cmuClock_DAC0, true);
|
|
|
|
DAC_Init_TypeDef init = DAC_INIT_DEFAULT;
|
|
|
|
/* Calculate the DAC clock prescaler value that will result in a DAC clock
|
|
* close to 500kHz. Second parameter is zero. This uses the current HFPERCLK
|
|
* frequency instead of setting a new one. */
|
|
init.prescale = DAC_PrescaleCalc(500000, REFERENCE_FREQUENCY);
|
|
|
|
/* Set reference voltage to VDD */
|
|
init.reference = dacRefVDD;
|
|
|
|
DAC_Init(obj->dac, &init);
|
|
dac_initialized = 1;
|
|
}
|
|
/* Use default channel settings */
|
|
DAC_InitChannel_TypeDef initChannel = DAC_INITCHANNEL_DEFAULT;
|
|
initChannel.enable = true;
|
|
DAC_InitChannel(obj->dac, &initChannel, obj->channel);
|
|
}
|
|
|
|
void analogout_free(dac_t *obj)
|
|
{
|
|
//Reset channel by re-initializing
|
|
DAC_InitChannel_TypeDef initChannel = DAC_INITCHANNEL_DEFAULT;
|
|
initChannel.enable = false;
|
|
DAC_InitChannel(obj->dac, &initChannel, obj->channel);
|
|
|
|
//Check all channels to see if we can disable the DAC completely
|
|
if((DAC0->CH0CTRL & DAC_CH0CTRL_EN) == 0 && (DAC0->CH1CTRL & DAC_CH1CTRL_EN) == 0) {
|
|
CMU_ClockEnable(cmuClock_DAC0, false);
|
|
dac_initialized = 0;
|
|
}
|
|
}
|
|
|
|
static inline void dac_write(dac_t *obj, int value)
|
|
{
|
|
switch (obj->channel) {
|
|
case 0:
|
|
obj->dac->CH0DATA = value;
|
|
break;
|
|
case 1:
|
|
obj->dac->CH1DATA = value;
|
|
break;
|
|
}
|
|
}
|
|
|
|
static inline int dac_read(dac_t *obj)
|
|
{
|
|
switch (obj->channel) {
|
|
case 0:
|
|
return obj->dac->CH0DATA;
|
|
break;
|
|
case 1:
|
|
return obj->dac->CH1DATA;
|
|
break;
|
|
default:
|
|
error("AnalogOut pin error. Invalid channel");
|
|
return -1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
void analogout_write(dac_t *obj, float value)
|
|
{
|
|
/* We multiply the float value with 0xFFF because the DAC has 12-bit resolution.
|
|
* Ie. accepts values between 0 and 0xFFF (4096). */
|
|
dac_write(obj, value*0xFFF);
|
|
}
|
|
|
|
void analogout_write_u16(dac_t *obj, uint16_t value)
|
|
{
|
|
/* The DAC has 12 bit resolution, so we remove the 4 least significant bits */
|
|
dac_write(obj, value >> 4);
|
|
}
|
|
|
|
float analogout_read(dac_t *obj)
|
|
{
|
|
/* dac_read returns a number between 0 and 0xFFF. Division gives us a float between 0 and 1 */
|
|
return dac_read(obj)/(float)0xFFF;
|
|
}
|
|
|
|
uint16_t analogout_read_u16(dac_t *obj)
|
|
{
|
|
/* dac_read returns a number with 12 significant digits,
|
|
* so we shift in 0s from right to make it a 16 bit number */
|
|
return dac_read(obj) << 4;
|
|
}
|
|
|
|
#endif
|