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-rw-r--r--Documentation/spi/spidev168
-rw-r--r--Documentation/spi/spidev_fdx.c158
2 files changed, 160 insertions, 166 deletions
diff --git a/Documentation/spi/spidev b/Documentation/spi/spidev
index 5c8e1b988a08..ed2da5e5b28a 100644
--- a/Documentation/spi/spidev
+++ b/Documentation/spi/spidev
@@ -126,8 +126,8 @@ NOTES:
126FULL DUPLEX CHARACTER DEVICE API 126FULL DUPLEX CHARACTER DEVICE API
127================================ 127================================
128 128
129See the sample program below for one example showing the use of the full 129See the spidev_fdx.c sample program for one example showing the use of the
130duplex programming interface. (Although it doesn't perform a full duplex 130full duplex programming interface. (Although it doesn't perform a full duplex
131transfer.) The model is the same as that used in the kernel spi_sync() 131transfer.) The model is the same as that used in the kernel spi_sync()
132request; the individual transfers offer the same capabilities as are 132request; the individual transfers offer the same capabilities as are
133available to kernel drivers (except that it's not asynchronous). 133available to kernel drivers (except that it's not asynchronous).
@@ -141,167 +141,3 @@ and bitrate for each transfer segment.)
141 141
142To make a full duplex request, provide both rx_buf and tx_buf for the 142To make a full duplex request, provide both rx_buf and tx_buf for the
143same transfer. It's even OK if those are the same buffer. 143same transfer. It's even OK if those are the same buffer.
144
145
146SAMPLE PROGRAM
147==============
148
149-------------------------------- CUT HERE
150#include <stdio.h>
151#include <unistd.h>
152#include <stdlib.h>
153#include <fcntl.h>
154#include <string.h>
155
156#include <sys/ioctl.h>
157#include <sys/types.h>
158#include <sys/stat.h>
159
160#include <linux/types.h>
161#include <linux/spi/spidev.h>
162
163
164static int verbose;
165
166static void do_read(int fd, int len)
167{
168 unsigned char buf[32], *bp;
169 int status;
170
171 /* read at least 2 bytes, no more than 32 */
172 if (len < 2)
173 len = 2;
174 else if (len > sizeof(buf))
175 len = sizeof(buf);
176 memset(buf, 0, sizeof buf);
177
178 status = read(fd, buf, len);
179 if (status < 0) {
180 perror("read");
181 return;
182 }
183 if (status != len) {
184 fprintf(stderr, "short read\n");
185 return;
186 }
187
188 printf("read(%2d, %2d): %02x %02x,", len, status,
189 buf[0], buf[1]);
190 status -= 2;
191 bp = buf + 2;
192 while (status-- > 0)
193 printf(" %02x", *bp++);
194 printf("\n");
195}
196
197static void do_msg(int fd, int len)
198{
199 struct spi_ioc_transfer xfer[2];
200 unsigned char buf[32], *bp;
201 int status;
202
203 memset(xfer, 0, sizeof xfer);
204 memset(buf, 0, sizeof buf);
205
206 if (len > sizeof buf)
207 len = sizeof buf;
208
209 buf[0] = 0xaa;
210 xfer[0].tx_buf = (__u64) buf;
211 xfer[0].len = 1;
212
213 xfer[1].rx_buf = (__u64) buf;
214 xfer[1].len = len;
215
216 status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);
217 if (status < 0) {
218 perror("SPI_IOC_MESSAGE");
219 return;
220 }
221
222 printf("response(%2d, %2d): ", len, status);
223 for (bp = buf; len; len--)
224 printf(" %02x", *bp++);
225 printf("\n");
226}
227
228static void dumpstat(const char *name, int fd)
229{
230 __u8 mode, lsb, bits;
231 __u32 speed;
232
233 if (ioctl(fd, SPI_IOC_RD_MODE, &mode) < 0) {
234 perror("SPI rd_mode");
235 return;
236 }
237 if (ioctl(fd, SPI_IOC_RD_LSB_FIRST, &lsb) < 0) {
238 perror("SPI rd_lsb_fist");
239 return;
240 }
241 if (ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits) < 0) {
242 perror("SPI bits_per_word");
243 return;
244 }
245 if (ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) < 0) {
246 perror("SPI max_speed_hz");
247 return;
248 }
249
250 printf("%s: spi mode %d, %d bits %sper word, %d Hz max\n",
251 name, mode, bits, lsb ? "(lsb first) " : "", speed);
252}
253
254int main(int argc, char **argv)
255{
256 int c;
257 int readcount = 0;
258 int msglen = 0;
259 int fd;
260 const char *name;
261
262 while ((c = getopt(argc, argv, "hm:r:v")) != EOF) {
263 switch (c) {
264 case 'm':
265 msglen = atoi(optarg);
266 if (msglen < 0)
267 goto usage;
268 continue;
269 case 'r':
270 readcount = atoi(optarg);
271 if (readcount < 0)
272 goto usage;
273 continue;
274 case 'v':
275 verbose++;
276 continue;
277 case 'h':
278 case '?':
279usage:
280 fprintf(stderr,
281 "usage: %s [-h] [-m N] [-r N] /dev/spidevB.D\n",
282 argv[0]);
283 return 1;
284 }
285 }
286
287 if ((optind + 1) != argc)
288 goto usage;
289 name = argv[optind];
290
291 fd = open(name, O_RDWR);
292 if (fd < 0) {
293 perror("open");
294 return 1;
295 }
296
297 dumpstat(name, fd);
298
299 if (msglen)
300 do_msg(fd, msglen);
301
302 if (readcount)
303 do_read(fd, readcount);
304
305 close(fd);
306 return 0;
307}
diff --git a/Documentation/spi/spidev_fdx.c b/Documentation/spi/spidev_fdx.c
new file mode 100644
index 000000000000..fc354f760384
--- /dev/null
+++ b/Documentation/spi/spidev_fdx.c
@@ -0,0 +1,158 @@
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 = (__u64) buf;
62 xfer[0].len = 1;
63
64 xfer[1].rx_buf = (__u64) 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 mode, lsb, bits;
82 __u32 speed;
83
84 if (ioctl(fd, SPI_IOC_RD_MODE, &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 %d, %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}
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