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}