xref: /linux/tools/spi/spidev_fdx.c (revision a3a4a816b4b194c45d0217e8b9e08b2639802cda)
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 
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 
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 
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 
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