1 ===============================
2 Linux USB Printer Gadget Driver
3 ===============================
4
5 06/04/2007
6
7 Copyright (C) 2007 Craig W. Nadler <craig@nadle
8
9
10
11 General
12 =======
13
14 This driver may be used if you are writing pri
15 the embedded OS. This driver has nothing to do
16 your Linux host system.
17
18 You will need a USB device controller and a Li
19 a gadget / "device class" driver using the Lin
20 USB device controller driver is loaded then lo
21 This will present a printer interface to the U
22 port is connected to.
23
24 This driver is structured for printer firmware
25 user mode printer firmware will read and write
26 printer gadget driver using a device file. The
27 byte when the USB HOST sends a device request
28 user space firmware can read or write this sta
29 /dev/g_printer . Both blocking and non-blockin
30
31
32
33
34 Howto Use This Driver
35 =====================
36
37 To load the USB device controller driver and t
38 following example uses the Netchip 2280 USB de
39
40 modprobe net2280
41 modprobe g_printer
42
43
44 The follow command line parameter can be used
45 (ex: modprobe g_printer idVendor=0x0525 idProd
46
47 idVendor
48 This is the Vendor ID used in the devi
49 the Netchip vendor id 0x0525. YOU MUST
50 BEFORE RELEASING A PRODUCT. If you pla
51 already have a Vendor ID please see ww
52 get one.
53
54 idProduct
55 This is the Product ID used in the dev
56 is 0xa4a8, you should change this to a
57 your other USB products if you have an
58 start numbering your products starting
59
60 bcdDevice
61 This is the version number of your pro
62 to put your firmware version here.
63
64 iManufacturer
65 A string containing the name of the Ve
66
67 iProduct
68 A string containing the Product Name.
69
70 iSerialNum
71 A string containing the Serial Number.
72 each unit of your product.
73
74 iPNPstring
75 The PNP ID string used for this printe
76 either on the command line or hard cod
77 your printer product.
78
79 qlen
80 The number of 8k buffers to use per en
81 should tune this for your product. You
82 size of each buffer for your product.
83
84
85
86
87 Using The Example Code
88 ======================
89
90 This example code talks to stdout, instead of
91
92 To compile the test code below:
93
94 1) save it to a file called prn_example.c
95 2) compile the code with the follow command::
96
97 gcc prn_example.c -o prn_example
98
99
100
101 To read printer data from the host to stdout::
102
103 # prn_example -read_data
104
105
106 To write printer data from a file (data_file)
107
108 # cat data_file | prn_example -write_d
109
110
111 To get the current printer status for the gadg
112
113 # prn_example -get_status
114
115 Printer status is:
116 Printer is NOT Selected
117 Paper is Out
118 Printer OK
119
120
121 To set printer to Selected/On-line::
122
123 # prn_example -selected
124
125
126 To set printer to Not Selected/Off-line::
127
128 # prn_example -not_selected
129
130
131 To set paper status to paper out::
132
133 # prn_example -paper_out
134
135
136 To set paper status to paper loaded::
137
138 # prn_example -paper_loaded
139
140
141 To set error status to printer OK::
142
143 # prn_example -no_error
144
145
146 To set error status to ERROR::
147
148 # prn_example -error
149
150
151
152
153 Example Code
154 ============
155
156 ::
157
158
159 #include <stdio.h>
160 #include <stdlib.h>
161 #include <fcntl.h>
162 #include <linux/poll.h>
163 #include <sys/ioctl.h>
164 #include <linux/usb/g_printer.h>
165
166 #define PRINTER_FILE "/dev/
167 #define BUF_SIZE 512
168
169
170 /*
171 * 'usage()' - Show program usage.
172 */
173
174 static void
175 usage(const char *option) /* I -
176 {
177 if (option) {
178 fprintf(stderr,"prn_example: U
179 option);
180 }
181
182 fputs("\n", stderr);
183 fputs("Usage: prn_example -[options]\n
184 fputs("Options:\n", stderr);
185 fputs("\n", stderr);
186 fputs("-get_status Get the current
187 fputs("-selected Set the selected
188 fputs("-not_selected Set the selected
189 stderr);
190 fputs("-error Set the error st
191 fputs("-no_error Set the error st
192 fputs("-paper_out Set the paper st
193 fputs("-paper_loaded Set the paper st
194 stderr);
195 fputs("-read_data Read printer dat
196 fputs("-write_data Write printer sa
197 fputs("-NB_read_data (Non-Blocking) R
198 stderr);
199 fputs("\n\n", stderr);
200
201 exit(1);
202 }
203
204
205 static int
206 read_printer_data()
207 {
208 struct pollfd fd[1];
209
210 /* Open device file for printer gadget
211 fd[0].fd = open(PRINTER_FILE, O_RDWR);
212 if (fd[0].fd < 0) {
213 printf("Error %d opening %s\n"
214 close(fd[0].fd);
215 return(-1);
216 }
217
218 fd[0].events = POLLIN | POLLRDNORM;
219
220 while (1) {
221 static char buf[BUF_SIZE];
222 int bytes_read;
223 int retval;
224
225 /* Wait for up to 1 second for
226 retval = poll(fd, 1, 1000);
227
228 if (retval && (fd[0].revents &
229
230 /* Read data from prin
231 bytes_read = read(fd[0
232
233 if (bytes_read < 0) {
234 printf("Error
235
236 close(fd[0].fd
237 return(-1);
238 } else if (bytes_read
239 /* Write data
240 fwrite(buf, 1,
241 fflush(stdout)
242 }
243
244 }
245
246 }
247
248 /* Close the device file. */
249 close(fd[0].fd);
250
251 return 0;
252 }
253
254
255 static int
256 write_printer_data()
257 {
258 struct pollfd fd[1];
259
260 /* Open device file for printer gadget
261 fd[0].fd = open (PRINTER_FILE, O_RDWR)
262 if (fd[0].fd < 0) {
263 printf("Error %d opening %s\n"
264 close(fd[0].fd);
265 return(-1);
266 }
267
268 fd[0].events = POLLOUT | POLLWRNORM;
269
270 while (1) {
271 int retval;
272 static char buf[BUF_SIZE];
273 /* Read data from standard INP
274 int bytes_read = fread(buf, 1,
275
276 if (!bytes_read) {
277 break;
278 }
279
280 while (bytes_read) {
281
282 /* Wait for up to 1 se
283 retval = poll(fd, 1, 1
284
285 /* Write data to print
286 if (retval && (fd[0].r
287 retval = write
288 if (retval < 0
289 printf
290
291
292 close(
293 return
294 } else {
295 bytes_
296 }
297
298 }
299
300 }
301
302 }
303
304 /* Wait until the data has been sent.
305 fsync(fd[0].fd);
306
307 /* Close the device file. */
308 close(fd[0].fd);
309
310 return 0;
311 }
312
313
314 static int
315 read_NB_printer_data()
316 {
317 int fd;
318 static char buf[BUF_SIZE];
319 int bytes_read;
320
321 /* Open device file for printer gadget
322 fd = open(PRINTER_FILE, O_RDWR|O_NONBL
323 if (fd < 0) {
324 printf("Error %d opening %s\n"
325 close(fd);
326 return(-1);
327 }
328
329 while (1) {
330 /* Read data from printer gadg
331 bytes_read = read(fd, buf, BUF
332 if (bytes_read <= 0) {
333 break;
334 }
335
336 /* Write data to standard OUTP
337 fwrite(buf, 1, bytes_read, std
338 fflush(stdout);
339 }
340
341 /* Close the device file. */
342 close(fd);
343
344 return 0;
345 }
346
347
348 static int
349 get_printer_status()
350 {
351 int retval;
352 int fd;
353
354 /* Open device file for printer gadget
355 fd = open(PRINTER_FILE, O_RDWR);
356 if (fd < 0) {
357 printf("Error %d opening %s\n"
358 close(fd);
359 return(-1);
360 }
361
362 /* Make the IOCTL call. */
363 retval = ioctl(fd, GADGET_GET_PRINTER_
364 if (retval < 0) {
365 fprintf(stderr, "ERROR: Failed
366 return(-1);
367 }
368
369 /* Close the device file. */
370 close(fd);
371
372 return(retval);
373 }
374
375
376 static int
377 set_printer_status(unsigned char buf, int cl
378 {
379 int retval;
380 int fd;
381
382 retval = get_printer_status();
383 if (retval < 0) {
384 fprintf(stderr, "ERROR: Failed
385 return(-1);
386 }
387
388 /* Open device file for printer gadget
389 fd = open(PRINTER_FILE, O_RDWR);
390
391 if (fd < 0) {
392 printf("Error %d opening %s\n"
393 close(fd);
394 return(-1);
395 }
396
397 if (clear_printer_status_bit) {
398 retval &= ~buf;
399 } else {
400 retval |= buf;
401 }
402
403 /* Make the IOCTL call. */
404 if (ioctl(fd, GADGET_SET_PRINTER_STATU
405 fprintf(stderr, "ERROR: Failed
406 return(-1);
407 }
408
409 /* Close the device file. */
410 close(fd);
411
412 return 0;
413 }
414
415
416 static int
417 display_printer_status()
418 {
419 char printer_status;
420
421 printer_status = get_printer_status();
422 if (printer_status < 0) {
423 fprintf(stderr, "ERROR: Failed
424 return(-1);
425 }
426
427 printf("Printer status is:\n");
428 if (printer_status & PRINTER_SELECTED)
429 printf(" Printer is Select
430 } else {
431 printf(" Printer is NOT Se
432 }
433 if (printer_status & PRINTER_PAPER_EMP
434 printf(" Paper is Out\n");
435 } else {
436 printf(" Paper is Loaded\n
437 }
438 if (printer_status & PRINTER_NOT_ERROR
439 printf(" Printer OK\n");
440 } else {
441 printf(" Printer ERROR\n")
442 }
443
444 return(0);
445 }
446
447
448 int
449 main(int argc, char *argv[])
450 {
451 int i; /* Looping var
452 int retval = 0;
453
454 /* No Args */
455 if (argc == 1) {
456 usage(0);
457 exit(0);
458 }
459
460 for (i = 1; i < argc && !retval; i ++)
461
462 if (argv[i][0] != '-') {
463 continue;
464 }
465
466 if (!strcmp(argv[i], "-get_sta
467 if (display_printer_st
468 retval = 1;
469 }
470
471 } else if (!strcmp(argv[i], "-
472 if (set_printer_status
473 retval = 1;
474 }
475
476 } else if (!strcmp(argv[i], "-
477 if (set_printer_status
478 retval = 1;
479 }
480
481 } else if (!strcmp(argv[i], "-
482 if (set_printer_status
483 retval = 1;
484 }
485
486 } else if (!strcmp(argv[i], "-
487 if (set_printer_status
488 retval = 1;
489 }
490
491 } else if (!strcmp(argv[i], "-
492 if (set_printer_status
493 retval = 1;
494 }
495
496 } else if (!strcmp(argv[i], "-
497 if (set_printer_status
498 retval = 1;
499 }
500
501 } else if (!strcmp(argv[i], "-
502 if (read_printer_data(
503 retval = 1;
504 }
505
506 } else if (!strcmp(argv[i], "-
507 if (write_printer_data
508 retval = 1;
509 }
510
511 } else if (!strcmp(argv[i], "-
512 if (read_NB_printer_da
513 retval = 1;
514 }
515
516 } else {
517 usage(argv[i]);
518 retval = 1;
519 }
520 }
521
522 exit(retval);
523 }
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