Documentation/spi/spidev_test.c

   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
  26 static void pabort(const char *s)
  27 {
  28         perror(s);
  29         abort();
  30 }
  31
  32 static const char *device = "/dev/spidev1.1";
  33 static uint32_t mode;
  34 static uint8_t bits = 8;
  35 static uint32_t speed = 500000;
  36 static uint16_t delay;
  37
  38 static 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         if (mode & SPI_TX_QUAD)
  61                 tr.tx_nbits = 4;
  62         else if (mode & SPI_TX_DUAL)
  63                 tr.tx_nbits = 2;
  64         if (mode & SPI_RX_QUAD)
  65                 tr.rx_nbits = 4;
  66         else if (mode & SPI_RX_DUAL)
  67                 tr.rx_nbits = 2;
  68         if (!(mode & SPI_LOOP)) {
  69                 if (mode & (SPI_TX_QUAD | SPI_TX_DUAL))
  70                         tr.rx_buf = 0;
  71                 else if (mode & (SPI_RX_QUAD | SPI_RX_DUAL))
  72                         tr.tx_buf = 0;
  73         }
  74
  75         ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
  76         if (ret < 1)
  77                 pabort("can't send spi message");
  78
  79         for (ret = 0; ret < ARRAY_SIZE(tx); ret++) {
  80                 if (!(ret % 6))
  81                         puts("");
  82                 printf("%.2X ", rx[ret]);
  83         }
  84         puts("");
  85 }
  86
  87 static void print_usage(const char *prog)
  88 {
  89         printf("Usage: %s [-DsbdlHOLC3]\n", prog);
  90         puts("  -D --device   device to use (default /dev/spidev1.1)\n"
  91              "  -s --speed    max speed (Hz)\n"
  92              "  -d --delay    delay (usec)\n"
  93              "  -b --bpw      bits per word \n"
  94              "  -l --loop     loopback\n"
  95              "  -H --cpha     clock phase\n"
  96              "  -O --cpol     clock polarity\n"
  97              "  -L --lsb      least significant bit first\n"
  98              "  -C --cs-high  chip select active high\n"
  99              "  -3 --3wire    SI/SO signals shared\n"
 100              "  -N --no-cs    no chip select\n"
 101              "  -R --ready    slave pulls low to pause\n"
 102              "  -2 --dual     dual transfer\n"
 103              "  -4 --quad     quad transfer\n");
 104         exit(1);
 105 }
 106
 107 static void parse_opts(int argc, char *argv[])
 108 {
 109         while (1) {
 110                 static const struct option lopts[] = {
 111                         { "device",  1, 0, 'D' },
 112                         { "speed",   1, 0, 's' },
 113                         { "delay",   1, 0, 'd' },
 114                         { "bpw",     1, 0, 'b' },
 115                         { "loop",    0, 0, 'l' },
 116                         { "cpha",    0, 0, 'H' },
 117                         { "cpol",    0, 0, 'O' },
 118                         { "lsb",     0, 0, 'L' },
 119                         { "cs-high", 0, 0, 'C' },
 120                         { "3wire",   0, 0, '3' },
 121                         { "no-cs",   0, 0, 'N' },
 122                         { "ready",   0, 0, 'R' },
 123                         { "dual",    0, 0, '2' },
 124                         { "quad",    0, 0, '4' },
 125                         { NULL, 0, 0, 0 },
 126                 };
 127                 int c;
 128
 129                 c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR24", lopts, NULL);
 130
 131                 if (c == -1)
 132                         break;
 133
 134                 switch (c) {
 135                 case 'D':
 136                         device = optarg;
 137                         break;
 138                 case 's':
 139                         speed = atoi(optarg);
 140                         break;
 141                 case 'd':
 142                         delay = atoi(optarg);
 143                         break;
 144                 case 'b':
 145                         bits = atoi(optarg);
 146                         break;
 147                 case 'l':
 148                         mode |= SPI_LOOP;
 149                         break;
 150                 case 'H':
 151                         mode |= SPI_CPHA;
 152                         break;
 153                 case 'O':
 154                         mode |= SPI_CPOL;
 155                         break;
 156                 case 'L':
 157                         mode |= SPI_LSB_FIRST;
 158                         break;
 159                 case 'C':
 160                         mode |= SPI_CS_HIGH;
 161                         break;
 162                 case '3':
 163                         mode |= SPI_3WIRE;
 164                         break;
 165                 case 'N':
 166                         mode |= SPI_NO_CS;
 167                         break;
 168                 case 'R':
 169                         mode |= SPI_READY;
 170                         break;
 171                 case '2':
 172                         mode |= SPI_TX_DUAL;
 173                         break;
 174                 case '4':
 175                         mode |= SPI_TX_QUAD;
 176                         break;
 177                 default:
 178                         print_usage(argv[0]);
 179                         break;
 180                 }
 181         }
 182         if (mode & SPI_LOOP) {
 183                 if (mode & SPI_TX_DUAL)
 184                         mode |= SPI_RX_DUAL;
 185                 if (mode & SPI_TX_QUAD)
 186                         mode |= SPI_RX_QUAD;
 187         }
 188 }
 189
 190 int main(int argc, char *argv[])
 191 {
 192         int ret = 0;
 193         int fd;
 194
 195         parse_opts(argc, argv);
 196
 197         fd = open(device, O_RDWR);
 198         if (fd < 0)
 199                 pabort("can't open device");
 200
 201         /*
 202          * spi mode
 203          */
 204         ret = ioctl(fd, SPI_IOC_WR_MODE32, &mode);
 205         if (ret == -1)
 206                 pabort("can't set spi mode");
 207
 208         ret = ioctl(fd, SPI_IOC_RD_MODE32, &mode);
 209         if (ret == -1)
 210                 pabort("can't get spi mode");
 211
 212         /*
 213          * bits per word
 214          */
 215         ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
 216         if (ret == -1)
 217                 pabort("can't set bits per word");
 218
 219         ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
 220         if (ret == -1)
 221                 pabort("can't get bits per word");
 222
 223         /*
 224          * max speed hz
 225          */
 226         ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
 227         if (ret == -1)
 228                 pabort("can't set max speed hz");
 229
 230         ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
 231         if (ret == -1)
 232                 pabort("can't get max speed hz");
 233
 234         printf("spi mode: 0x%x\n", mode);
 235         printf("bits per word: %d\n", bits);
 236         printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
 237
 238         transfer(fd);
 239
 240         close(fd);
 241
 242         return ret;
 243 }