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Diffstat (limited to 'libmaple/adc.c')
-rw-r--r-- | libmaple/adc.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/libmaple/adc.c b/libmaple/adc.c new file mode 100644 index 0000000..7ea85dd --- /dev/null +++ b/libmaple/adc.c @@ -0,0 +1,109 @@ +/****************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Perry Hung. + * 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/adc.c + * @author Marti Bolivar <mbolivar@leaflabs.com>, + * Perry Hung <perry@leaflabs.com> + * @brief Analog to digital converter routines + */ + +#include <libmaple/adc.h> +#include <libmaple/libmaple.h> +#include <libmaple/rcc.h> + +/** + * @brief Initialize an ADC peripheral. + * + * Initializes the RCC clock line for the given peripheral. Resets + * ADC device registers. + * + * @param dev ADC peripheral to initialize + */ +void adc_init(const adc_dev *dev) { + rcc_clk_enable(dev->clk_id); + rcc_reset_dev(dev->clk_id); +} + +/** + * @brief Set external event select for regular group + * @param dev ADC device + * @param event Event used to trigger the start of conversion. + * @see adc_extsel_event + */ +void adc_set_extsel(const adc_dev *dev, adc_extsel_event event) { + uint32 cr2 = dev->regs->CR2; + cr2 &= ~ADC_CR2_EXTSEL; + cr2 |= event; + dev->regs->CR2 = cr2; +} + +/** + * @brief Set the sample rate for all channels on an ADC device. + * + * Don't call this during conversion. + * + * @param dev adc device + * @param smp_rate sample rate to set + * @see adc_smp_rate + */ +void adc_set_sample_rate(const adc_dev *dev, adc_smp_rate smp_rate) { + uint32 adc_smpr1_val = 0, adc_smpr2_val = 0; + int i; + + for (i = 0; i < 10; i++) { + if (i < 8) { + /* ADC_SMPR1 determines sample time for channels [10,17] */ + adc_smpr1_val |= smp_rate << (i * 3); + } + /* ADC_SMPR2 determines sample time for channels [0,9] */ + adc_smpr2_val |= smp_rate << (i * 3); + } + + dev->regs->SMPR1 = adc_smpr1_val; + dev->regs->SMPR2 = adc_smpr2_val; +} + +/** + * @brief Perform a single synchronous software triggered conversion on a + * channel. + * @param dev ADC device to use for reading. + * @param channel channel to convert + * @return conversion result + */ +uint16 adc_read(const adc_dev *dev, uint8 channel) { + adc_reg_map *regs = dev->regs; + + adc_set_reg_seqlen(dev, 1); + + regs->SQR3 = channel; + regs->CR2 |= ADC_CR2_SWSTART; + while (!(regs->SR & ADC_SR_EOC)) + ; + + return (uint16)(regs->DR & ADC_DR_DATA); +} |