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