xref: /kernel/linux/linux-6.6/tools/spi/spidev_fdx.c (revision 62306a36)
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
16static int verbose;
17
18static 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
49static 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
80static 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, %d Hz max\n",
103		name, mode, bits, lsb ? "(lsb first) " : "", speed);
104}
105
106int 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 '?':
131usage:
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