Linux Kernel  3.7.1
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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 <[email protected]>
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 uint8_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  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 
72 static void 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 
88 static void 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  { "no-cs", 0, 0, 'N' },
103  { "ready", 0, 0, 'R' },
104  { NULL, 0, 0, 0 },
105  };
106  int c;
107 
108  c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR", lopts, NULL);
109 
110  if (c == -1)
111  break;
112 
113  switch (c) {
114  case 'D':
115  device = optarg;
116  break;
117  case 's':
118  speed = atoi(optarg);
119  break;
120  case 'd':
121  delay = atoi(optarg);
122  break;
123  case 'b':
124  bits = atoi(optarg);
125  break;
126  case 'l':
127  mode |= SPI_LOOP;
128  break;
129  case 'H':
130  mode |= SPI_CPHA;
131  break;
132  case 'O':
133  mode |= SPI_CPOL;
134  break;
135  case 'L':
136  mode |= SPI_LSB_FIRST;
137  break;
138  case 'C':
139  mode |= SPI_CS_HIGH;
140  break;
141  case '3':
142  mode |= SPI_3WIRE;
143  break;
144  case 'N':
145  mode |= SPI_NO_CS;
146  break;
147  case 'R':
148  mode |= SPI_READY;
149  break;
150  default:
151  print_usage(argv[0]);
152  break;
153  }
154  }
155 }
156 
157 int main(int argc, char *argv[])
158 {
159  int ret = 0;
160  int fd;
161 
162  parse_opts(argc, argv);
163 
164  fd = open(device, O_RDWR);
165  if (fd < 0)
166  pabort("can't open device");
167 
168  /*
169  * spi mode
170  */
171  ret = ioctl(fd, SPI_IOC_WR_MODE, &mode);
172  if (ret == -1)
173  pabort("can't set spi mode");
174 
175  ret = ioctl(fd, SPI_IOC_RD_MODE, &mode);
176  if (ret == -1)
177  pabort("can't get spi mode");
178 
179  /*
180  * bits per word
181  */
182  ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
183  if (ret == -1)
184  pabort("can't set bits per word");
185 
186  ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
187  if (ret == -1)
188  pabort("can't get bits per word");
189 
190  /*
191  * max speed hz
192  */
193  ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
194  if (ret == -1)
195  pabort("can't set max speed hz");
196 
197  ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
198  if (ret == -1)
199  pabort("can't get max speed hz");
200 
201  printf("spi mode: %d\n", mode);
202  printf("bits per word: %d\n", bits);
203  printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
204 
205  transfer(fd);
206 
207  close(fd);
208 
209  return ret;
210 }