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
15static int verbose;
16
17static 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
48static 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
79static 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
105int 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 '?':
130usage:
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