linux/Documentation/spi/spidev_test.c
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   1/*
   2 * SPI testing utility (using spidev driver)
   3 *
   4 * Copyright (c) 2007  MontaVista Software, Inc.
   5 * Copyright (c) 2007  Anton Vorontsov <avorontsov@ru.mvista.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License.
  10 *
  11 * Cross-compile with cross-gcc -I/path/to/cross-kernel/include
  12 */
  13
  14#include <stdint.h>
  15#include <unistd.h>
  16#include <stdio.h>
  17#include <stdlib.h>
  18#include <getopt.h>
  19#include <fcntl.h>
  20#include <sys/ioctl.h>
  21#include <linux/types.h>
  22#include <linux/spi/spidev.h>
  23
  24#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
  25
  26static void pabort(const char *s)
  27{
  28        perror(s);
  29        abort();
  30}
  31
  32static const char *device = "/dev/spidev1.1";
  33static uint8_t mode;
  34static uint8_t bits = 8;
  35static uint32_t speed = 500000;
  36static uint16_t delay;
  37
  38static void transfer(int fd)
  39{
  40        int ret;
  41        uint8_t tx[] = {
  42                0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  43                0x40, 0x00, 0x00, 0x00, 0x00, 0x95,
  44                0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  45                0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  46                0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  47                0xDE, 0xAD, 0xBE, 0xEF, 0xBA, 0xAD,
  48                0xF0, 0x0D,
  49        };
  50        uint8_t rx[ARRAY_SIZE(tx)] = {0, };
  51        struct spi_ioc_transfer tr = {
  52                .tx_buf = (unsigned long)tx,
  53                .rx_buf = (unsigned long)rx,
  54                .len = ARRAY_SIZE(tx),
  55                .delay_usecs = delay,
  56                .speed_hz = speed,
  57                .bits_per_word = bits,
  58        };
  59
  60        ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
  61        if (ret == 1)
  62                pabort("can't send spi message");
  63
  64        for (ret = 0; ret < ARRAY_SIZE(tx); ret++) {
  65                if (!(ret % 6))
  66                        puts("");
  67                printf("%.2X ", rx[ret]);
  68        }
  69        puts("");
  70}
  71
  72void print_usage(const char *prog)
  73{
  74        printf("Usage: %s [-DsbdlHOLC3]\n", prog);
  75        puts("  -D --device   device to use (default /dev/spidev1.1)\n"
  76             "  -s --speed    max speed (Hz)\n"
  77             "  -d --delay    delay (usec)\n"
  78             "  -b --bpw      bits per word \n"
  79             "  -l --loop     loopback\n"
  80             "  -H --cpha     clock phase\n"
  81             "  -O --cpol     clock polarity\n"
  82             "  -L --lsb      least significant bit first\n"
  83             "  -C --cs-high  chip select active high\n"
  84             "  -3 --3wire    SI/SO signals shared\n");
  85        exit(1);
  86}
  87
  88void parse_opts(int argc, char *argv[])
  89{
  90        while (1) {
  91                static const struct option lopts[] = {
  92                        { "device",  1, 0, 'D' },
  93                        { "speed",   1, 0, 's' },
  94                        { "delay",   1, 0, 'd' },
  95                        { "bpw",     1, 0, 'b' },
  96                        { "loop",    0, 0, 'l' },
  97                        { "cpha",    0, 0, 'H' },
  98                        { "cpol",    0, 0, 'O' },
  99                        { "lsb",     0, 0, 'L' },
 100                        { "cs-high", 0, 0, 'C' },
 101                        { "3wire",   0, 0, '3' },
 102                        { NULL, 0, 0, 0 },
 103                };
 104                int c;
 105
 106                c = getopt_long(argc, argv, "D:s:d:b:lHOLC3", lopts, NULL);
 107
 108                if (c == -1)
 109                        break;
 110
 111                switch (c) {
 112                case 'D':
 113                        device = optarg;
 114                        break;
 115                case 's':
 116                        speed = atoi(optarg);
 117                        break;
 118                case 'd':
 119                        delay = atoi(optarg);
 120                        break;
 121                case 'b':
 122                        bits = atoi(optarg);
 123                        break;
 124                case 'l':
 125                        mode |= SPI_LOOP;
 126                        break;
 127                case 'H':
 128                        mode |= SPI_CPHA;
 129                        break;
 130                case 'O':
 131                        mode |= SPI_CPOL;
 132                        break;
 133                case 'L':
 134                        mode |= SPI_LSB_FIRST;
 135                        break;
 136                case 'C':
 137                        mode |= SPI_CS_HIGH;
 138                        break;
 139                case '3':
 140                        mode |= SPI_3WIRE;
 141                        break;
 142                default:
 143                        print_usage(argv[0]);
 144                        break;
 145                }
 146        }
 147}
 148
 149int main(int argc, char *argv[])
 150{
 151        int ret = 0;
 152        int fd;
 153
 154        parse_opts(argc, argv);
 155
 156        fd = open(device, O_RDWR);
 157        if (fd < 0)
 158                pabort("can't open device");
 159
 160        /*
 161         * spi mode
 162         */
 163        ret = ioctl(fd, SPI_IOC_WR_MODE, &mode);
 164        if (ret == -1)
 165                pabort("can't set spi mode");
 166
 167        ret = ioctl(fd, SPI_IOC_RD_MODE, &mode);
 168        if (ret == -1)
 169                pabort("can't get spi mode");
 170
 171        /*
 172         * bits per word
 173         */
 174        ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
 175        if (ret == -1)
 176                pabort("can't set bits per word");
 177
 178        ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
 179        if (ret == -1)
 180                pabort("can't get bits per word");
 181
 182        /*
 183         * max speed hz
 184         */
 185        ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
 186        if (ret == -1)
 187                pabort("can't set max speed hz");
 188
 189        ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
 190        if (ret == -1)
 191                pabort("can't get max speed hz");
 192
 193        printf("spi mode: %d\n", mode);
 194        printf("bits per word: %d\n", bits);
 195        printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
 196
 197        transfer(fd);
 198
 199        close(fd);
 200
 201        return ret;
 202}
 203