forked from Archive/PX4-Autopilot
104 lines
3.1 KiB
C++
104 lines
3.1 KiB
C++
/****************************************************************************
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*
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* Copyright (C) 2020 PX4 Development Team. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name PX4 nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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#include <board_config.h>
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#include <drivers/drv_adc.h>
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#include <px4_platform_common/log.h>
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#include <fcntl.h>
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#include <stdint.h>
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#include <unistd.h>
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#define ADC_SYSFS_PATH "/sys/kernel/rcio/adc"
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#define ADC_MAX_CHAN 6
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int _channels_fd[ADC_MAX_CHAN];
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int px4_arch_adc_init(uint32_t base_address)
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{
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for (int i = 0; i < ADC_MAX_CHAN; i++) {
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_channels_fd[i] = -1;
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}
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return 0;
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}
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void px4_arch_adc_uninit(uint32_t base_address)
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{
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for (int i = 0; i < ADC_MAX_CHAN; i++) {
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::close(_channels_fd[i]);
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_channels_fd[i] = -1;
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}
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}
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uint32_t px4_arch_adc_sample(uint32_t base_address, unsigned channel)
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{
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if (channel > ADC_MAX_CHAN) {
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PX4_ERR("channel %d out of range: %d", channel, ADC_MAX_CHAN);
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return UINT32_MAX; // error
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}
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// open channel if necessary
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if (_channels_fd[channel] == -1) {
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// ADC_SYSFS_PATH
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char channel_path[strlen(ADC_SYSFS_PATH) + 5] {};
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if (sprintf(channel_path, "%s/ch%d", ADC_SYSFS_PATH, channel) == -1) {
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PX4_ERR("adc channel: %d\n", channel);
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return UINT32_MAX; // error
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}
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_channels_fd[channel] = ::open(channel_path, O_RDONLY);
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}
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char buffer[10] {};
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if (::pread(_channels_fd[channel], buffer, sizeof(buffer), 0) < 0) {
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PX4_ERR("read channel %d failed", channel);
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return UINT32_MAX; // error
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}
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return atoi(buffer);
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}
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float px4_arch_adc_reference_v()
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{
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return BOARD_ADC_POS_REF_V;
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}
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uint32_t px4_arch_adc_dn_fullcount()
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{
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return 1 << 12; // 12 bit ADC
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}
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