1 #include <stdio.h>
2 #include <unistd.h>
3 #include <stdlib.h>
4 #include <fcntl.h>
5 #include <string.h>
6
7 #include <sys/ioctl.h>
8 #include <sys/types.h>
9 #include <sys/stat.h>
10
11 #include <linux/types.h>
12 #include <linux/spi/spidev.h>
13
14
15 static int verbose;
16
do_read(int fd,int len)17 static void do_read(int fd, int len)
18 {
19 unsigned char buf[32], *bp;
20 int status;
21
22 /* read at least 2 bytes, no more than 32 */
23 if (len < 2)
24 len = 2;
25 else if (len > sizeof(buf))
26 len = sizeof(buf);
27 memset(buf, 0, sizeof buf);
28
29 status = read(fd, buf, len);
30 if (status < 0) {
31 perror("read");
32 return;
33 }
34 if (status != len) {
35 fprintf(stderr, "short read\n");
36 return;
37 }
38
39 printf("read(%2d, %2d): %02x %02x,", len, status,
40 buf[0], buf[1]);
41 status -= 2;
42 bp = buf + 2;
43 while (status-- > 0)
44 printf(" %02x", *bp++);
45 printf("\n");
46 }
47
do_msg(int fd,int len)48 static void do_msg(int fd, int len)
49 {
50 struct spi_ioc_transfer xfer[2];
51 unsigned char buf[32], *bp;
52 int status;
53
54 memset(xfer, 0, sizeof xfer);
55 memset(buf, 0, sizeof buf);
56
57 if (len > sizeof buf)
58 len = sizeof buf;
59
60 buf[0] = 0xaa;
61 xfer[0].tx_buf = (unsigned long)buf;
62 xfer[0].len = 1;
63
64 xfer[1].rx_buf = (unsigned long) buf;
65 xfer[1].len = len;
66
67 status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);
68 if (status < 0) {
69 perror("SPI_IOC_MESSAGE");
70 return;
71 }
72
73 printf("response(%2d, %2d): ", len, status);
74 for (bp = buf; len; len--)
75 printf(" %02x", *bp++);
76 printf("\n");
77 }
78
dumpstat(const char * name,int fd)79 static void dumpstat(const char *name, int fd)
80 {
81 __u8 lsb, bits;
82 __u32 mode, speed;
83
84 if (ioctl(fd, SPI_IOC_RD_MODE32, &mode) < 0) {
85 perror("SPI rd_mode");
86 return;
87 }
88 if (ioctl(fd, SPI_IOC_RD_LSB_FIRST, &lsb) < 0) {
89 perror("SPI rd_lsb_fist");
90 return;
91 }
92 if (ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits) < 0) {
93 perror("SPI bits_per_word");
94 return;
95 }
96 if (ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) < 0) {
97 perror("SPI max_speed_hz");
98 return;
99 }
100
101 printf("%s: spi mode 0x%x, %d bits %sper word, %d Hz max\n",
102 name, mode, bits, lsb ? "(lsb first) " : "", speed);
103 }
104
main(int argc,char ** argv)105 int main(int argc, char **argv)
106 {
107 int c;
108 int readcount = 0;
109 int msglen = 0;
110 int fd;
111 const char *name;
112
113 while ((c = getopt(argc, argv, "hm:r:v")) != EOF) {
114 switch (c) {
115 case 'm':
116 msglen = atoi(optarg);
117 if (msglen < 0)
118 goto usage;
119 continue;
120 case 'r':
121 readcount = atoi(optarg);
122 if (readcount < 0)
123 goto usage;
124 continue;
125 case 'v':
126 verbose++;
127 continue;
128 case 'h':
129 case '?':
130 usage:
131 fprintf(stderr,
132 "usage: %s [-h] [-m N] [-r N] /dev/spidevB.D\n",
133 argv[0]);
134 return 1;
135 }
136 }
137
138 if ((optind + 1) != argc)
139 goto usage;
140 name = argv[optind];
141
142 fd = open(name, O_RDWR);
143 if (fd < 0) {
144 perror("open");
145 return 1;
146 }
147
148 dumpstat(name, fd);
149
150 if (msglen)
151 do_msg(fd, msglen);
152
153 if (readcount)
154 do_read(fd, readcount);
155
156 close(fd);
157 return 0;
158 }
159