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//
// Copyright 2017 Ettus Research (National Instruments)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
#include <stdint.h>
/*! Initialize a spidev interface
*
* \param fd Return value of the file descriptor
* \param device Path of spidev device, e.g. "/dev/spidev0.0"
* \param mode SPI mode. See linux/spi/spidev.h
* \param speed_hz The *maximum* SPI speed in Hz
* \param bits_per_word Just set it to 8.
* \param delay_us Delay between writes in microseconds
*
* \returns 0 if all is good, or an error code otherwise
*/
int init_spi(int *fd, const char *device,
const uint32_t mode,
const uint32_t speed_hz,
const uint8_t bits_per_word,
const uint16_t delay_us
);
/*! Do a SPI transaction over spidev
*
* \param tx Buffer of data to be written
* \param rx Must match tx buffer length; result will be written here
* \param len Total number of bytes in this transaction
* \param speed_hz Speed of this transaction in Hz
* \param bits_per_word 8, dude
* \param delay_us Delay between transfers
*
* Assumption: spidev was configured properly beforehand.
*
* \returns 0 if all is golden
*/
int transfer(
int fd,
uint8_t *tx, uint8_t *rx, uint32_t len,
uint32_t speed_hz, uint8_t bits_per_word, uint16_t delay_us
);
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