1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h>
3 #include <unistd.h>
4 #include <stdlib.h>
5 #include <fcntl.h>
6 #include <string.h>
7
8 #include <sys/ioctl.h>
9 #include <sys/types.h>
10 #include <sys/stat.h>
11
12 #include <linux/types.h>
13 #include <linux/spi/spidev.h>
14
15
16 static int verbose;
17
18 static void do_read(int fd, int len)
19 {
20 unsigned char buf[32], *bp;
21 int status;
22
23 /* read at least 2 bytes, no more than 32 */
24 if (len < 2)
25 len = 2;
26 else if (len > sizeof(buf))
27 len = sizeof(buf);
28 memset(buf, 0, sizeof buf);
29
30 status = read(fd, buf, len);
31 if (status < 0) {
32 perror("read");
33 return;
34 }
35 if (status != len) {
36 fprintf(stderr, "short read\n");
37 return;
38 }
39
40 printf("read(%2d, %2d): %02x %02x,", len, status,
41 buf[0], buf[1]);
42 status -= 2;
43 bp = buf + 2;
44 while (status-- > 0)
45 printf(" %02x", *bp++);
46 printf("\n");
47 }
48
49 static void do_msg(int fd, int len)
50 {
51 struct spi_ioc_transfer xfer[2];
52 unsigned char buf[32], *bp;
53 int status;
54
55 memset(xfer, 0, sizeof xfer);
56 memset(buf, 0, sizeof buf);
57
58 if (len > sizeof buf)
59 len = sizeof buf;
60
61 buf[0] = 0xaa;
62 xfer[0].tx_buf = (unsigned long)buf;
63 xfer[0].len = 1;
64
65 xfer[1].rx_buf = (unsigned long) buf;
66 xfer[1].len = len;
67
68 status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);
69 if (status < 0) {
70 perror("SPI_IOC_MESSAGE");
71 return;
72 }
73
74 printf("response(%2d, %2d): ", len, status);
75 for (bp = buf; len; len--)
76 printf(" %02x", *bp++);
77 printf("\n");
78 }
79
80 static void dumpstat(const char *name, int fd)
81 {
82 __u8 lsb, bits;
83 __u32 mode, speed;
84
85 if (ioctl(fd, SPI_IOC_RD_MODE32, &mode) < 0) {
86 perror("SPI rd_mode");
87 return;
88 }
89 if (ioctl(fd, SPI_IOC_RD_LSB_FIRST, &lsb) < 0) {
90 perror("SPI rd_lsb_fist");
91 return;
92 }
93 if (ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits) < 0) {
94 perror("SPI bits_per_word");
95 return;
96 }
97 if (ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) < 0) {
98 perror("SPI max_speed_hz");
99 return;
100 }
101
102 printf("%s: spi mode 0x%x, %d bits %sper word, %u Hz max\n",
103 name, mode, bits, lsb ? "(lsb first) " : "", speed);
104 }
105
106 int main(int argc, char **argv)
107 {
108 int c;
109 int readcount = 0;
110 int msglen = 0;
111 int fd;
112 const char *name;
113
114 while ((c = getopt(argc, argv, "hm:r:v")) != EOF) {
115 switch (c) {
116 case 'm':
117 msglen = atoi(optarg);
118 if (msglen < 0)
119 goto usage;
120 continue;
121 case 'r':
122 readcount = atoi(optarg);
123 if (readcount < 0)
124 goto usage;
125 continue;
126 case 'v':
127 verbose++;
128 continue;
129 case 'h':
130 case '?':
131 usage:
132 fprintf(stderr,
133 "usage: %s [-h] [-m N] [-r N] /dev/spidevB.D\n",
134 argv[0]);
135 return 1;
136 }
137 }
138
139 if ((optind + 1) != argc)
140 goto usage;
141 name = argv[optind];
142
143 fd = open(name, O_RDWR);
144 if (fd < 0) {
145 perror("open");
146 return 1;
147 }
148
149 dumpstat(name, fd);
150
151 if (msglen)
152 do_msg(fd, msglen);
153
154 if (readcount)
155 do_read(fd, readcount);
156
157 close(fd);
158 return 0;
159 }
160
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