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/******************************************************************************
* The MIT License
*
* Copyright (c) 2010 Bryan Newbold.
* Copyright (c) 2011, 2012 LeafLabs, LLC.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*****************************************************************************/
/**
* @file libmaple/dac.c
* @brief Digital to analog converter support.
*/
#include <libmaple/dac.h>
#include <libmaple/libmaple.h>
#include <libmaple/gpio.h>
#if STM32_HAVE_DAC
dac_dev dac = {
.regs = DAC_BASE,
};
const dac_dev *DAC = &dac;
#endif
/**
* @brief Initialize the digital to analog converter
* @param dev DAC device
* @param flags Flags:
* DAC_CH1: Enable channel 1
* DAC_CH2: Enable channel 2
* @sideeffect May set PA4 or PA5 to INPUT_ANALOG
*/
void dac_init(const dac_dev *dev, uint32 flags) {
/* First turn on the clock */
rcc_clk_enable(RCC_DAC);
rcc_reset_dev(RCC_DAC);
if (flags & DAC_CH1) {
dac_enable_channel(dev, 1);
}
if (flags & DAC_CH2) {
dac_enable_channel(dev, 2);
}
}
/**
* @brief Write a 12-bit value to the DAC to output
* @param dev DAC device
* @param channel channel to select (1 or 2)
* @param val value to write
*/
void dac_write_channel(const dac_dev *dev, uint8 channel, uint16 val) {
switch(channel) {
case 1:
dev->regs->DHR12R1 = DAC_DHR12R1_DACC1DHR & val;
break;
case 2:
dev->regs->DHR12R2 = DAC_DHR12R2_DACC2DHR & val;
break;
}
}
/**
* @brief Enable a DAC channel
* @param dev DAC device
* @param channel channel to enable, either 1 or 2
* @sideeffect May change pin mode of PA4 or PA5
*/
void dac_enable_channel(const dac_dev *dev, uint8 channel) {
/*
* Setup ANALOG mode on PA4 and PA5. This mapping is consistent
* across all supported STM32s with a DAC.
*/
switch (channel) {
case 1:
gpio_set_mode(GPIOA, 4, GPIO_MODE_ANALOG);
dev->regs->CR |= DAC_CR_EN1;
break;
case 2:
gpio_set_mode(GPIOA, 5, GPIO_MODE_ANALOG);
dev->regs->CR |= DAC_CR_EN2;
break;
}
}
/**
* @brief Disable a DAC channel
* @param dev DAC device
* @param channel channel to disable, either 1 or 2
*/
void dac_disable_channel(const dac_dev *dev, uint8 channel) {
switch (channel) {
case 1:
dev->regs->CR &= ~DAC_CR_EN1;
break;
case 2:
dev->regs->CR &= ~DAC_CR_EN2;
break;
}
}
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