Here I am attaching my SPI Test program in C. The problem with this code is, when I run this code, it is printing TX data bytes on console but not RX data bytes. Can anyone say what's wrong with my code?
Anyone please check my code and suggest me the changes required to make it work for both reading and writing to SPI.
/*
* SPI testing utility (using spidev driver)
*
* Copyright (c) 2007 MontaVista Software, Inc.
* Copyright (c) 2007 Anton Vorontsov <avorontsov@ru.mvista.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 2 of the License.
*
* Cross-compile with cross-gcc -I/path/to/cross-kernel/include
*/
#include <stdint.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <fcntl.h>
#include <time.h>
#include <sys/ioctl.h>
#include <linux/ioctl.h>
#include <sys/stat.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>
#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
static void pabort(const char *s)
{
perror(s);
abort();
}
uint8_t default_tx[] = {
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0x40, 0x00, 0x00, 0x00, 0x00, 0x95,
0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
//0xF0, 0x0D,
};
static const char *device = "/dev/spidev0.0";
static uint32_t mode;
static uint8_t bits = 8;
static char *input_file;
static char *output_file;
static uint32_t speed = 500000;
static uint16_t delay;
static int verbose=1;
static int transfer_size = sizeof(default_tx);
static int iterations;
static int interval = 5; /* interval in seconds for showing transfer rate */
uint8_t default_rx[ARRAY_SIZE(default_tx)] = {0, };
char *input_tx;
static void hex_dump(const void *src, size_t length, size_t line_size,
char *prefix)
{
//printf("Entered HEX_DUMP()\n");
int i = 0;
const unsigned char *address = src;
const unsigned char *line = address;
unsigned char c;
printf("%s | ", prefix);
while (length-- > 0) {
printf("%02X ", *address++);
if (!(++i % line_size) || (length == 0 && i % line_size)) {
if (length == 0) {
while (i++ % line_size)
printf("__ ");
}
printf(" | "); /* right close */
while (line < address) {
c = *line++;
printf("%c", (c < 33 || c == 255) ? 0x2E : c);
}
printf("\n");
if (length > 0)
printf("%s | ", prefix);
}
}
//printf("Exiting HEX_DUMP()\n");
}
/*
* Unescape - process hexadecimal escape character
* converts shell input "\x23" -> 0x23
*/
static int unescape(char *_dst, char *_src, size_t len)
{
printf("Entered unescape()\n");
int ret = 0;
int match;
char *src = _src;
char *dst = _dst;
unsigned int ch;
while (*src) {
if (*src == '\\' && *(src+1) == 'x') {
match = sscanf(src + 2, "%2x", &ch);
if (!match)
pabort("malformed input string");
src += 4;
*dst++ = (unsigned char)ch;
} else {
*dst++ = *src++;
}
ret++;
}
printf("Exiting unescape()\n");
return ret;
}
static void transfer(int fd, uint8_t const *tx, uint8_t const *rx, size_t len)
{
printf("Entered Transfer()\n");
int ret;
int out_fd;
struct spi_ioc_transfer tr = {
.tx_buf = (unsigned long)tx,
.rx_buf = (unsigned long)rx,
.len = len,
.delay_usecs = delay,
.speed_hz = speed,
.bits_per_word = bits,
};
//printf("Transfer()\n\tMode: %d\tSPI_TX_QUAD: %d\tSPI_TX_DUAL: %d\n",mode,SPI_TX_QUAD,SPI_TX_DUAL);
if (mode & SPI_TX_QUAD)
tr.tx_nbits = 4;
else if (mode & SPI_TX_DUAL)
tr.tx_nbits = 2;
//printf("Transfer()\n\tMode: %d\tSPI_RX_QUAD: %d\tSPI_RX_DUAL: %d\n",mode,SPI_RX_QUAD,SPI_RX_DUAL);
if (mode & SPI_RX_QUAD)
tr.rx_nbits = 4;
else if (mode & SPI_RX_DUAL)
tr.rx_nbits = 2;
if (!(mode & SPI_LOOP)) {
if (mode & (SPI_TX_QUAD | SPI_TX_DUAL))
tr.rx_buf = 0;
else if (mode & (SPI_RX_QUAD | SPI_RX_DUAL))
tr.tx_buf = 0;
}
ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
if (ret < 1)
pabort("can't send spi message");
//printf("Transfer()\n\tVerbose: %d\toutput_file: %d",verbose,output_file);
if (verbose)
hex_dump(tx, len, 32, "TX");
// if (output_file) {
out_fd = open(output_file, O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (out_fd < 0)
pabort("could not open output file");
ret = write(out_fd, rx, len);
if (ret != len)
pabort("not all bytes written to output file");
close(out_fd);
// }
if (verbose)
hex_dump(rx, len, 32, "RX");
printf("Exited Transfer()\n");
}
static void print_usage(const char *prog)
{
printf("Usage: %s [-DsbdlHOLC3vpNR24SI]\n", prog);
puts(" -D --device device to use (default /dev/spidev1.1)\n"
" -s --speed max speed (Hz)\n"
" -d --delay delay (usec)\n"
" -b --bpw bits per word\n"
" -i --input input data from a file (e.g. \"test.bin\")\n"
" -o --output output data to a file (e.g. \"results.bin\")\n"
" -l --loop loopback\n"
" -H --cpha clock phase\n"
" -O --cpol clock polarity\n"
" -L --lsb least significant bit first\n"
" -C --cs-high chip select active high\n"
" -3 --3wire SI/SO signals shared\n"
" -v --verbose Verbose (show tx buffer)\n"
" -p Send data (e.g. \"1234\\xde\\xad\")\n"
" -N --no-cs no chip select\n"
" -R --ready slave pulls low to pause\n"
" -2 --dual dual transfer\n"
" -4 --quad quad transfer\n"
" -S --size transfer size\n"
" -I --iter iterations\n");
exit(1);
}
static void parse_opts(int argc, char *argv[])
{
while (1) {
static const struct option lopts[] = {
{ "device", 1, 0, 'D' },
{ "speed", 1, 0, 's' },
{ "delay", 1, 0, 'd' },
{ "bpw", 1, 0, 'b' },
{ "input", 1, 0, 'i' },
{ "output", 1, 0, 'o' },
{ "loop", 0, 0, 'l' },
{ "cpha", 0, 0, 'H' },
{ "cpol", 0, 0, 'O' },
{ "lsb", 0, 0, 'L' },
{ "cs-high", 0, 0, 'C' },
{ "3wire", 0, 0, '3' },
{ "no-cs", 0, 0, 'N' },
{ "ready", 0, 0, 'R' },
{ "dual", 0, 0, '2' },
{ "verbose", 0, 0, 'v' },
{ "quad", 0, 0, '4' },
{ "size", 1, 0, 'S' },
{ "iter", 1, 0, 'I' },
{ NULL, 0, 0, 0 },
};
int c;
c = getopt_long(argc, argv, "D:s:d:b:i:o:lHOLC3NR24p:vS:I:",
lopts, NULL);
if (c == -1)
break;
switch (c) {
case 'D':
device = optarg;
break;
case 's':
speed = atoi(optarg);
break;
case 'd':
delay = atoi(optarg);
break;
case 'b':
bits = atoi(optarg);
break;
case 'i':
input_file = optarg;
break;
case 'o':
output_file = optarg;
break;
case 'l':
mode |= SPI_LOOP;
break;
case 'H':
mode |= SPI_CPHA;
break;
case 'O':
mode |= SPI_CPOL;
break;
case 'L':
mode |= SPI_LSB_FIRST;
break;
case 'C':
mode |= SPI_CS_HIGH;
break;
case '3':
mode |= SPI_3WIRE;
break;
case 'N':
mode |= SPI_NO_CS;
break;
case 'v':
verbose = 1;
break;
case 'R':
mode |= SPI_READY;
break;
case 'p':
input_tx = optarg;
break;
case '2':
mode |= SPI_TX_DUAL;
break;
case '4':
mode |= SPI_TX_QUAD;
break;
case 'S':
transfer_size = atoi(optarg);
break;
case 'I':
iterations = atoi(optarg);
break;
default:
print_usage(argv[0]);
break;
}
}
if (mode & SPI_LOOP) {
if (mode & SPI_TX_DUAL)
mode |= SPI_RX_DUAL;
if (mode & SPI_TX_QUAD)
mode |= SPI_RX_QUAD;
}
}
static void transfer_escaped_string(int fd, char *str)
{
printf("Entered transfer_escaped_string()\n");
size_t size = strlen(str);
uint8_t *tx;
uint8_t *rx;
tx = malloc(size);
if (!tx)
pabort("can't allocate tx buffer");
rx = malloc(size);
if (!rx)
pabort("can't allocate rx buffer");
size = unescape((char *)tx, str, size);
//printf("Entering transfer() from transfer_escaped_string\n");
transfer(fd, tx, rx, size);
//printf("Exited transfer() in transfer_escaped_string\n");
free(rx);
free(tx);
//printf("Exited transfer_escaped_string()\n");
}
static void transfer_file(int fd, char *filename)
{
//printf("Entered transfer_file()\n");
ssize_t bytes;
struct stat sb;
int tx_fd;
uint8_t *tx;
uint8_t *rx;
if (stat(filename, &sb) == -1)
pabort("can't stat input file");
tx_fd = open(filename, O_RDONLY);
if (tx_fd < 0)
pabort("can't open input file");
tx = malloc(sb.st_size);
if (!tx)
pabort("can't allocate tx buffer");
rx = malloc(sb.st_size);
if (!rx)
pabort("can't allocate rx buffer");
bytes = read(tx_fd, tx, sb.st_size);
if (bytes != sb.st_size)
pabort("failed to read input file");
//printf("Calling transfer() from transfer_file\n");
transfer(fd, tx, rx, sb.st_size);
//printf("Came back from transfer(). Now in transfer_file\n");
free(rx);
free(tx);
close(tx_fd);
//printf("Exiting transfer_file()\n");
}
static uint64_t _read_count;
static uint64_t _write_count;
static void show_transfer_rate(void)
{
//printf("in show_transfer_rate()\n");
static uint64_t prev_read_count, prev_write_count;
double rx_rate, tx_rate;
rx_rate = ((_read_count - prev_read_count) * 8) / (interval*1000.0);
tx_rate = ((_write_count - prev_write_count) * 8) / (interval*1000.0);
//printf("rate: tx %.1fkbps, rx %.1fkbps\n", rx_rate, tx_rate);
prev_read_count = _read_count;
prev_write_count = _write_count;
//printf("Exiting show_transfer_rate()\n");
}
static void transfer_buf(int fd, int len)
{
//printf("Entered transfer_buf()\n");
uint8_t *tx;
uint8_t *rx;
int i;
tx = malloc(len);
if (!tx)
pabort("can't allocate tx buffer");
for (i = 0; i < len; i++)
tx[i] = random();
rx = malloc(len);
if (!rx)
pabort("can't allocate rx buffer");
transfer(fd, tx, rx, len);
_write_count += len;
_read_count += len;
if (mode & SPI_LOOP) {
if (memcmp(tx, rx, len)) {
fprintf(stderr, "transfer error !\n");
hex_dump(tx, len, 32, "TX");
hex_dump(rx, len, 32, "RX");
exit(1);
}
}
free(rx);
free(tx);
//printf("Exiting transfer_buf()\n");
}
int main(int argc, char *argv[])
{
int ret = 0;
int fd;
parse_opts(argc, argv);
fd = open(device, O_RDWR);
if (fd < 0)
pabort("can't open device");
/*
* spi mode
*/
ret = ioctl(fd, SPI_IOC_WR_MODE32, &mode);
if (ret == -1)
pabort("can't set spi mode");
ret = ioctl(fd, SPI_IOC_RD_MODE32, &mode);
if (ret == -1)
pabort("can't get spi mode");
/*
* bits per word
*/
ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
if (ret == -1)
pabort("can't set bits per word");
ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
if (ret == -1)
pabort("can't get bits per word");
/*
* max speed hz
*/
ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
if (ret == -1)
pabort("can't set max speed hz");
ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
if (ret == -1)
pabort("can't get max speed hz");
printf("spi mode: 0x%x\n", mode);
printf("bits per word: %d\n", bits);
printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
if (input_tx && input_file)
pabort("only one of -p and --input may be selected");
if (input_tx)
transfer_escaped_string(fd, input_tx);
// else if (input_file)
// transfer_file(fd, input_file);
else if (transfer_size) {
struct timespec last_stat;
clock_gettime(CLOCK_MONOTONIC, &last_stat);
while (iterations-- > 0) {
struct timespec current;
transfer_buf(fd, transfer_size);
clock_gettime(CLOCK_MONOTONIC, ¤t);
if (current.tv_sec - last_stat.tv_sec > interval) {
show_transfer_rate();
last_stat = current;
}
}
printf("total: tx %.1fKB, rx %.1fKB\n",
_write_count/1024.0, _read_count/1024.0);
} else
//printf("Calling transfer()\n");
transfer(fd, default_tx, default_rx, sizeof(default_tx));
//printf("After transfer()\n");
close(fd);
return ret;
}
