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/*
* generic SPI functions
*
* Copyright 2013, 2014 Zefir Kurtisi <zefir.kurtisi@gmail.com>
*
* 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. See COPYING for more details.
*/
#include "spi-context.h"
#include "logging.h"
#include "miner.h"
#include <fcntl.h>
#include <sys/ioctl.h>
#include <assert.h>
#include <unistd.h>
struct spi_ctx *spi_init(struct spi_config *config)
{
char dev_fname[PATH_MAX];
struct spi_ctx *ctx;
if (config == NULL)
return NULL;
sprintf(dev_fname, SPI_DEVICE_TEMPLATE, config->bus, config->cs_line);
int fd = open(dev_fname, O_RDWR);
if (fd < 0) {
applog(LOG_ERR, "SPI: Can not open SPI device %s", dev_fname);
return NULL;
}
if ((ioctl(fd, SPI_IOC_WR_MODE, &config->mode) < 0) ||
(ioctl(fd, SPI_IOC_RD_MODE, &config->mode) < 0) ||
(ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &config->bits) < 0) ||
(ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &config->bits) < 0) ||
(ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &config->speed) < 0) ||
(ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &config->speed) < 0)) {
applog(LOG_ERR, "SPI: ioctl error on SPI device %s", dev_fname);
close(fd);
return NULL;
}
ctx = malloc(sizeof(*ctx));
assert(ctx != NULL);
ctx->fd = fd;
ctx->config = *config;
applog(LOG_WARNING, "SPI '%s': mode=%hhu, bits=%hhu, speed=%u",
dev_fname, ctx->config.mode, ctx->config.bits,
ctx->config.speed);
return ctx;
}
extern void spi_exit(struct spi_ctx *ctx)
{
if (NULL == ctx)
return;
close(ctx->fd);
free(ctx);
}
extern bool spi_transfer(struct spi_ctx *ctx, uint8_t *txbuf,
uint8_t *rxbuf, int len)
{
struct spi_ioc_transfer xfr;
int ret;
if (rxbuf != NULL)
memset(rxbuf, 0xff, len);
ret = len;
xfr.tx_buf = (unsigned long)txbuf;
xfr.rx_buf = (unsigned long)rxbuf;
xfr.len = len;
xfr.speed_hz = ctx->config.speed;
xfr.delay_usecs = ctx->config.delay;
xfr.bits_per_word = ctx->config.bits;
xfr.cs_change = 0;
xfr.pad = 0;
ret = ioctl(ctx->fd, SPI_IOC_MESSAGE(1), &xfr);
if (ret < 1)
applog(LOG_ERR, "SPI: ioctl error on SPI device: %d", ret);
return ret > 0;
}