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 <string.h>
  19 #include <getopt.h>
  20 #include <fcntl.h>
  21 #include <sys/ioctl.h>
  22 #include <linux/types.h>
  23 #include <linux/spi/spidev.h>
  24
  25 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
  26
  27 static void pabort(const char *s)
  28 {
  29         perror(s);
  30         abort();
  31 }
  32
  33 static const char *device = "/dev/spidev1.1";
  34 static uint32_t mode;
  35 static uint8_t bits = 8;
  36 static uint32_t speed = 500000;
  37 static uint16_t delay;
  38 static int verbose;
  39
  40 uint8_t default_tx[] = {
  41         0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  42         0x40, 0x00, 0x00, 0x00, 0x00, 0x95,
  43         0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  44         0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  45         0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  46         0xF0, 0x0D,
  47 };
  48
  49 uint8_t default_rx[ARRAY_SIZE(default_tx)] = {0, };
  50 char *input_tx;
  51
  52 static void hex_dump(const void *src, size_t length, size_t line_size, char *prefix)
  53 {
  54         int i = 0;
  55         const unsigned char *address = src;
  56         const unsigned char *line = address;
  57         unsigned char c;
  58
  59         printf("%s | ", prefix);
  60         while (length-- > 0) {
  61                 printf("%02X ", *address++);
  62                 if (!(++i % line_size) || (length == 0 && i % line_size)) {
  63                         if (length == 0) {
  64                                 while (i++ % line_size)
  65                                         printf("__ ");
  66                         }
  67                         printf(" | ");  /* right close */
  68                         while (line < address) {
  69                                 c = *line++;
  70                                 printf("%c", (c < 33 || c == 255) ? 0x2E : c);
  71                         }
  72                         printf("\n");
  73                         if (length > 0)
  74                                 printf("%s | ", prefix);
  75                 }
  76         }
  77 }
  78
  79 /*
  80  *  Unescape - process hexadecimal escape character
  81  *      converts shell input "\x23" -> 0x23
  82  */
  83 static int unescape(char *_dst, char *_src, size_t len)
  84 {
  85         int ret = 0;
  86         char *src = _src;
  87         char *dst = _dst;
  88         unsigned int ch;
  89
  90         while (*src) {
  91                 if (*src == '\\' && *(src+1) == 'x') {
  92                         sscanf(src + 2, "%2x", &ch);
  93                         src += 4;
  94                         *dst++ = (unsigned char)ch;
  95                 } else {
  96                         *dst++ = *src++;
  97                 }
  98                 ret++;
  99         }
 100         return ret;
 101 }
 102
 103 static void transfer(int fd, uint8_t const *tx, uint8_t const *rx, size_t len)
 104 {
 105         int ret;
 106
 107         struct spi_ioc_transfer tr = {
 108                 .tx_buf = (unsigned long)tx,
 109                 .rx_buf = (unsigned long)rx,
 110                 .len = len,
 111                 .delay_usecs = delay,
 112                 .speed_hz = speed,
 113                 .bits_per_word = bits,
 114         };
 115
 116         if (mode & SPI_TX_QUAD)
 117                 tr.tx_nbits = 4;
 118         else if (mode & SPI_TX_DUAL)
 119                 tr.tx_nbits = 2;
 120         if (mode & SPI_RX_QUAD)
 121                 tr.rx_nbits = 4;
 122         else if (mode & SPI_RX_DUAL)
 123                 tr.rx_nbits = 2;
 124         if (!(mode & SPI_LOOP)) {
 125                 if (mode & (SPI_TX_QUAD | SPI_TX_DUAL))
 126                         tr.rx_buf = 0;
 127                 else if (mode & (SPI_RX_QUAD | SPI_RX_DUAL))
 128                         tr.tx_buf = 0;
 129         }
 130
 131         ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
 132         if (ret < 1)
 133                 pabort("can't send spi message");
 134
 135         if (verbose)
 136                 hex_dump(tx, len, 32, "TX");
 137         hex_dump(rx, len, 32, "RX");
 138 }
 139
 140 static void print_usage(const char *prog)
 141 {
 142         printf("Usage: %s [-DsbdlHOLC3]\n", prog);
 143         puts("  -D --device   device to use (default /dev/spidev1.1)\n"
 144              "  -s --speed    max speed (Hz)\n"
 145              "  -d --delay    delay (usec)\n"
 146              "  -b --bpw      bits per word \n"
 147              "  -l --loop     loopback\n"
 148              "  -H --cpha     clock phase\n"
 149              "  -O --cpol     clock polarity\n"
 150              "  -L --lsb      least significant bit first\n"
 151              "  -C --cs-high  chip select active high\n"
 152              "  -3 --3wire    SI/SO signals shared\n"
 153              "  -v --verbose  Verbose (show tx buffer)\n"
 154              "  -p            Send data (e.g. \"1234\\xde\\xad\")\n"
 155              "  -N --no-cs    no chip select\n"
 156              "  -R --ready    slave pulls low to pause\n"
 157              "  -2 --dual     dual transfer\n"
 158              "  -4 --quad     quad transfer\n");
 159         exit(1);
 160 }
 161
 162 static void parse_opts(int argc, char *argv[])
 163 {
 164         while (1) {
 165                 static const struct option lopts[] = {
 166                         { "device",  1, 0, 'D' },
 167                         { "speed",   1, 0, 's' },
 168                         { "delay",   1, 0, 'd' },
 169                         { "bpw",     1, 0, 'b' },
 170                         { "loop",    0, 0, 'l' },
 171                         { "cpha",    0, 0, 'H' },
 172                         { "cpol",    0, 0, 'O' },
 173                         { "lsb",     0, 0, 'L' },
 174                         { "cs-high", 0, 0, 'C' },
 175                         { "3wire",   0, 0, '3' },
 176                         { "no-cs",   0, 0, 'N' },
 177                         { "ready",   0, 0, 'R' },
 178                         { "dual",    0, 0, '2' },
 179                         { "verbose", 0, 0, 'v' },
 180                         { "quad",    0, 0, '4' },
 181                         { NULL, 0, 0, 0 },
 182                 };
 183                 int c;
 184
 185                 c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR24p:v", lopts, NULL);
 186
 187                 if (c == -1)
 188                         break;
 189
 190                 switch (c) {
 191                 case 'D':
 192                         device = optarg;
 193                         break;
 194                 case 's':
 195                         speed = atoi(optarg);
 196                         break;
 197                 case 'd':
 198                         delay = atoi(optarg);
 199                         break;
 200                 case 'b':
 201                         bits = atoi(optarg);
 202                         break;
 203                 case 'l':
 204                         mode |= SPI_LOOP;
 205                         break;
 206                 case 'H':
 207                         mode |= SPI_CPHA;
 208                         break;
 209                 case 'O':
 210                         mode |= SPI_CPOL;
 211                         break;
 212                 case 'L':
 213                         mode |= SPI_LSB_FIRST;
 214                         break;
 215                 case 'C':
 216                         mode |= SPI_CS_HIGH;
 217                         break;
 218                 case '3':
 219                         mode |= SPI_3WIRE;
 220                         break;
 221                 case 'N':
 222                         mode |= SPI_NO_CS;
 223                         break;
 224                 case 'v':
 225                         verbose = 1;
 226                         break;
 227                 case 'R':
 228                         mode |= SPI_READY;
 229                         break;
 230                 case 'p':
 231                         input_tx = optarg;
 232                         break;
 233                 case '2':
 234                         mode |= SPI_TX_DUAL;
 235                         break;
 236                 case '4':
 237                         mode |= SPI_TX_QUAD;
 238                         break;
 239                 default:
 240                         print_usage(argv[0]);
 241                         break;
 242                 }
 243         }
 244         if (mode & SPI_LOOP) {
 245                 if (mode & SPI_TX_DUAL)
 246                         mode |= SPI_RX_DUAL;
 247                 if (mode & SPI_TX_QUAD)
 248                         mode |= SPI_RX_QUAD;
 249         }
 250 }
 251
 252 int main(int argc, char *argv[])
 253 {
 254         int ret = 0;
 255         int fd;
 256         uint8_t *tx;
 257         uint8_t *rx;
 258         int size;
 259
 260         parse_opts(argc, argv);
 261
 262         fd = open(device, O_RDWR);
 263         if (fd < 0)
 264                 pabort("can't open device");
 265
 266         /*
 267          * spi mode
 268          */
 269         ret = ioctl(fd, SPI_IOC_WR_MODE32, &mode);
 270         if (ret == -1)
 271                 pabort("can't set spi mode");
 272
 273         ret = ioctl(fd, SPI_IOC_RD_MODE32, &mode);
 274         if (ret == -1)
 275                 pabort("can't get spi mode");
 276
 277         /*
 278          * bits per word
 279          */
 280         ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
 281         if (ret == -1)
 282                 pabort("can't set bits per word");
 283
 284         ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
 285         if (ret == -1)
 286                 pabort("can't get bits per word");
 287
 288         /*
 289          * max speed hz
 290          */
 291         ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
 292         if (ret == -1)
 293                 pabort("can't set max speed hz");
 294
 295         ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
 296         if (ret == -1)
 297                 pabort("can't get max speed hz");
 298
 299         printf("spi mode: 0x%x\n", mode);
 300         printf("bits per word: %d\n", bits);
 301         printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
 302
 303         if (input_tx) {
 304                 size = strlen(input_tx+1);
 305                 tx = malloc(size);
 306                 rx = malloc(size);
 307                 size = unescape((char *)tx, input_tx, size);
 308                 transfer(fd, tx, rx, size);
 309                 free(rx);
 310                 free(tx);
 311         } else {
 312                 transfer(fd, default_tx, default_rx, sizeof(default_tx));
 313         }
 314
 315         close(fd);
 316
 317         return ret;
 318 }