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Based on kernel version 3.16. Page generated on 2014-08-06 21:41 EST.

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	}
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