dac.c
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/*
* Copyright (C) 2016 Eistec AB
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup cpu_kinetis_common
* @ingroup drivers_periph_dac
*
* @{
*
* @file
* @brief Low-level DAC driver implementation
*
* This driver uses the 12-bit in-CPU DAC module. The 6-bit digital-to-analog
* converter inside the CMP module is _not_ used by this implementation.
*
* @author Joakim Nohlgård <joakim.nohlgard@eistec.se>
*
* @}
*/
#include <stdint.h>
#include "cpu.h"
#include "bit.h"
#include "assert.h"
#include "periph/dac.h"
#include "periph_conf.h"
/* only compile this file if there are DAC lines defined */
#ifdef DAC_NUMOF
static inline DAC_Type *dev(dac_t line)
{
return dac_config[line].dev;
}
int8_t dac_init(dac_t line)
{
if (line >= DAC_NUMOF) {
return DAC_NOLINE;
}
/* Enable module clock */
bit_set32(dac_config[line].scgc_addr, dac_config[line].scgc_bit);
/* Select VDDA as voltage reference */
dev(line)->C0 = (DAC_C0_DACRFS_MASK);
/* Disable DMA and buffering */
dev(line)->C1 = 0;
dev(line)->C2 = 0;
/* Enable the device */
bit_set8(&dac_config[line].dev->C0, DAC_C0_DACEN_SHIFT);
/* Set output value to zero */
dac_set(line, 0);
return DAC_OK;
}
void dac_set(dac_t line, uint16_t value)
{
assert(line < DAC_NUMOF);
/* Scale to 12 bit */
value = (value >> 4);
dev(line)->DAT[0].DATH = ((value >> 8) & 0xff);
dev(line)->DAT[0].DATL = (value & 0xff);
}
void dac_poweron(dac_t line)
{
assert(line < DAC_NUMOF);
bit_set8(&dac_config[line].dev->C0, DAC_C0_DACEN_SHIFT);
}
void dac_poweroff(dac_t line)
{
assert(line < DAC_NUMOF);
bit_clear8(&dac_config[line].dev->C0, DAC_C0_DACEN_SHIFT);
}
#endif /* DAC_NUMOF */