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spidev_test.c

/*
 * 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 <getopt.h>
#include <fcntl.h>
#include <sys/ioctl.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();
}

static const char *device = "/dev/spidev1.1";
static uint8_t mode;
static uint8_t bits = 8;
static uint32_t speed = 500000;
static uint16_t delay;

static void transfer(int fd)
{
      int ret;
      uint8_t tx[] = {
            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
            0x40, 0x00, 0x00, 0x00, 0x00, 0x95,
            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
            0xDE, 0xAD, 0xBE, 0xEF, 0xBA, 0xAD,
            0xF0, 0x0D,
      };
      uint8_t rx[ARRAY_SIZE(tx)] = {0, };
      struct spi_ioc_transfer tr = {
            .tx_buf = (unsigned long)tx,
            .rx_buf = (unsigned long)rx,
            .len = ARRAY_SIZE(tx),
            .delay_usecs = delay,
            .speed_hz = speed,
            .bits_per_word = bits,
      };

      ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
      if (ret == 1)
            pabort("can't send spi message");

      for (ret = 0; ret < ARRAY_SIZE(tx); ret++) {
            if (!(ret % 6))
                  puts("");
            printf("%.2X ", rx[ret]);
      }
      puts("");
}

void print_usage(const char *prog)
{
      printf("Usage: %s [-DsbdlHOLC3]\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"
           "  -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");
      exit(1);
}

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' },
                  { "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' },
                  { NULL, 0, 0, 0 },
            };
            int c;

            c = getopt_long(argc, argv, "D:s:d:b:lHOLC3", 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 '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;
            default:
                  print_usage(argv[0]);
                  break;
            }
      }
}

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_MODE, &mode);
      if (ret == -1)
            pabort("can't set spi mode");

      ret = ioctl(fd, SPI_IOC_RD_MODE, &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: %d\n", mode);
      printf("bits per word: %d\n", bits);
      printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);

      transfer(fd);

      close(fd);

      return ret;
}

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