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 
do_read(int fd,int len)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 
do_msg(int fd,int len)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 
dumpstat(const char * name,int fd)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, %d Hz max\n",
103 		name, mode, bits, lsb ? "(lsb first) " : "", speed);
104 }
105 
main(int argc,char ** argv)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