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/******************************************************************************
* The MIT License
*
* Copyright (c) 2010 Bryan Newbold.
*
* 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.
*****************************************************************************/
#include "libmaple.h"
#include "gpio.h"
#include "dac.h"
/**
* @brief DAC peripheral routines.
*/
dac_dev dac = {
.regs = DAC_BASE,
};
const dac_dev *DAC = &dac;
/**
* @brief Initialize the digital to analog converter
* @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(uint32 flags) {
/* First turn on the clock */
rcc_clk_enable(RCC_DAC);
rcc_reset_dev(RCC_DAC);
if (flags & DAC_CH1) {
dac_enable_channel(1);
}
if (flags & DAC_CH2) {
dac_enable_channel(2);
}
}
/**
* @brief Write a 12-bit value to the DAC to output
* @param channel channel to select (1 or 2)
* @param val value to write
*/
void dac_write_channel(uint8 channel, uint16 val) {
switch(channel) {
case 1:
DAC->regs->DHR12R1 = DAC_DHR12R1_DACC1DHR & val;
break;
case 2:
DAC->regs->DHR12R2 = DAC_DHR12R2_DACC2DHR & val;
break;
}
}
/**
* @brief Enable a DAC channel
* @param channel channel to enable, either 1 or 2
* @sideeffect May change pin mode of PA4 or PA5
*/
void dac_enable_channel(uint8 channel) {
/*
* Setup ANALOG mode on PA4 and PA5. This mapping is consistent across
* all STM32 chips with a DAC. See RM008 12.2.
*/
switch (channel) {
case 1:
gpio_set_mode(GPIOA_BASE, 4, GPIO_MODE_INPUT_ANALOG);
DAC->regs->CR |= DAC_CR_EN1;
break;
case 2:
gpio_set_mode(GPIOA_BASE, 5, GPIO_MODE_INPUT_ANALOG);
DAC->regs->CR |= DAC_CR_EN2;
break;
}
}
/**
* @brief Disable a DAC channel
* @param channel channel to disable, either 1 or 2
*/
void dac_disable_channel(uint8 channel) {
switch (channel) {
case 1:
DAC->regs->CR &= ~DAC_CR_EN1;
break;
case 2:
DAC->regs->CR &= ~DAC_CR_EN2;
break;
}
}
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