Commit | Line | Data |
---|---|---|
d80b5005 MCC |
1 | =============================== |
2 | Linux USB Printer Gadget Driver | |
3 | =============================== | |
25a010c8 | 4 | |
d80b5005 | 5 | 06/04/2007 |
25a010c8 | 6 | |
d80b5005 | 7 | Copyright (C) 2007 Craig W. Nadler <craig@nadler.us> |
25a010c8 CN |
8 | |
9 | ||
10 | ||
d80b5005 | 11 | General |
25a010c8 CN |
12 | ======= |
13 | ||
14 | This driver may be used if you are writing printer firmware using Linux as | |
15 | the embedded OS. This driver has nothing to do with using a printer with | |
16 | your Linux host system. | |
17 | ||
18 | You will need a USB device controller and a Linux driver for it that accepts | |
19 | a gadget / "device class" driver using the Linux USB Gadget API. After the | |
20 | USB device controller driver is loaded then load the printer gadget driver. | |
21 | This will present a printer interface to the USB Host that your USB Device | |
22 | port is connected to. | |
23 | ||
24 | This driver is structured for printer firmware that runs in user mode. The | |
25 | user mode printer firmware will read and write data from the kernel mode | |
26 | printer gadget driver using a device file. The printer returns a printer status | |
27 | byte when the USB HOST sends a device request to get the printer status. The | |
28 | user space firmware can read or write this status byte using a device file | |
29 | /dev/g_printer . Both blocking and non-blocking read/write calls are supported. | |
30 | ||
31 | ||
32 | ||
33 | ||
d80b5005 | 34 | Howto Use This Driver |
25a010c8 CN |
35 | ===================== |
36 | ||
37 | To load the USB device controller driver and the printer gadget driver. The | |
d80b5005 | 38 | following example uses the Netchip 2280 USB device controller driver:: |
25a010c8 | 39 | |
d80b5005 MCC |
40 | modprobe net2280 |
41 | modprobe g_printer | |
25a010c8 CN |
42 | |
43 | ||
44 | The follow command line parameter can be used when loading the printer gadget | |
45 | (ex: modprobe g_printer idVendor=0x0525 idProduct=0xa4a8 ): | |
46 | ||
d80b5005 MCC |
47 | idVendor |
48 | This is the Vendor ID used in the device descriptor. The default is | |
25a010c8 CN |
49 | the Netchip vendor id 0x0525. YOU MUST CHANGE TO YOUR OWN VENDOR ID |
50 | BEFORE RELEASING A PRODUCT. If you plan to release a product and don't | |
51 | already have a Vendor ID please see www.usb.org for details on how to | |
52 | get one. | |
53 | ||
d80b5005 MCC |
54 | idProduct |
55 | This is the Product ID used in the device descriptor. The default | |
25a010c8 CN |
56 | is 0xa4a8, you should change this to an ID that's not used by any of |
57 | your other USB products if you have any. It would be a good idea to | |
58 | start numbering your products starting with say 0x0001. | |
59 | ||
d80b5005 MCC |
60 | bcdDevice |
61 | This is the version number of your product. It would be a good idea | |
25a010c8 CN |
62 | to put your firmware version here. |
63 | ||
d80b5005 MCC |
64 | iManufacturer |
65 | A string containing the name of the Vendor. | |
25a010c8 | 66 | |
d80b5005 MCC |
67 | iProduct |
68 | A string containing the Product Name. | |
25a010c8 | 69 | |
d80b5005 MCC |
70 | iSerialNum |
71 | A string containing the Serial Number. This should be changed for | |
25a010c8 CN |
72 | each unit of your product. |
73 | ||
d80b5005 MCC |
74 | iPNPstring |
75 | The PNP ID string used for this printer. You will want to set | |
25a010c8 CN |
76 | either on the command line or hard code the PNP ID string used for |
77 | your printer product. | |
78 | ||
d80b5005 MCC |
79 | qlen |
80 | The number of 8k buffers to use per endpoint. The default is 10, you | |
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81 | should tune this for your product. You may also want to tune the |
82 | size of each buffer for your product. | |
83 | ||
84 | ||
85 | ||
86 | ||
d80b5005 | 87 | Using The Example Code |
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88 | ====================== |
89 | ||
90 | This example code talks to stdout, instead of a print engine. | |
91 | ||
92 | To compile the test code below: | |
93 | ||
94 | 1) save it to a file called prn_example.c | |
d80b5005 MCC |
95 | 2) compile the code with the follow command:: |
96 | ||
25a010c8 CN |
97 | gcc prn_example.c -o prn_example |
98 | ||
99 | ||
100 | ||
d80b5005 | 101 | To read printer data from the host to stdout:: |
25a010c8 CN |
102 | |
103 | # prn_example -read_data | |
104 | ||
105 | ||
d80b5005 | 106 | To write printer data from a file (data_file) to the host:: |
25a010c8 CN |
107 | |
108 | # cat data_file | prn_example -write_data | |
109 | ||
110 | ||
d80b5005 | 111 | To get the current printer status for the gadget driver::: |
25a010c8 CN |
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 | ||
d80b5005 | 121 | To set printer to Selected/On-line:: |
25a010c8 CN |
122 | |
123 | # prn_example -selected | |
124 | ||
125 | ||
d80b5005 | 126 | To set printer to Not Selected/Off-line:: |
25a010c8 CN |
127 | |
128 | # prn_example -not_selected | |
129 | ||
130 | ||
d80b5005 | 131 | To set paper status to paper out:: |
25a010c8 CN |
132 | |
133 | # prn_example -paper_out | |
134 | ||
135 | ||
d80b5005 | 136 | To set paper status to paper loaded:: |
25a010c8 CN |
137 | |
138 | # prn_example -paper_loaded | |
139 | ||
140 | ||
d80b5005 | 141 | To set error status to printer OK:: |
25a010c8 CN |
142 | |
143 | # prn_example -no_error | |
144 | ||
145 | ||
d80b5005 | 146 | To set error status to ERROR:: |
25a010c8 CN |
147 | |
148 | # prn_example -error | |
149 | ||
150 | ||
151 | ||
152 | ||
d80b5005 | 153 | Example Code |
25a010c8 CN |
154 | ============ |
155 | ||
d80b5005 MCC |
156 | :: |
157 | ||
25a010c8 | 158 | |
d80b5005 MCC |
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> | |
25a010c8 | 165 | |
d80b5005 MCC |
166 | #define PRINTER_FILE "/dev/g_printer" |
167 | #define BUF_SIZE 512 | |
25a010c8 CN |
168 | |
169 | ||
d80b5005 MCC |
170 | /* |
171 | * 'usage()' - Show program usage. | |
172 | */ | |
25a010c8 | 173 | |
d80b5005 MCC |
174 | static void |
175 | usage(const char *option) /* I - Option string or NULL */ | |
176 | { | |
25a010c8 CN |
177 | if (option) { |
178 | fprintf(stderr,"prn_example: Unknown option \"%s\"!\n", | |
179 | option); | |
180 | } | |
181 | ||
182 | fputs("\n", stderr); | |
183 | fputs("Usage: prn_example -[options]\n", stderr); | |
184 | fputs("Options:\n", stderr); | |
185 | fputs("\n", stderr); | |
186 | fputs("-get_status Get the current printer status.\n", stderr); | |
187 | fputs("-selected Set the selected status to selected.\n", stderr); | |
188 | fputs("-not_selected Set the selected status to NOT selected.\n", | |
189 | stderr); | |
190 | fputs("-error Set the error status to error.\n", stderr); | |
191 | fputs("-no_error Set the error status to NO error.\n", stderr); | |
192 | fputs("-paper_out Set the paper status to paper out.\n", stderr); | |
193 | fputs("-paper_loaded Set the paper status to paper loaded.\n", | |
194 | stderr); | |
195 | fputs("-read_data Read printer data from driver.\n", stderr); | |
196 | fputs("-write_data Write printer sata to driver.\n", stderr); | |
197 | fputs("-NB_read_data (Non-Blocking) Read printer data from driver.\n", | |
198 | stderr); | |
199 | fputs("\n\n", stderr); | |
200 | ||
201 | exit(1); | |
d80b5005 | 202 | } |
25a010c8 CN |
203 | |
204 | ||
d80b5005 MCC |
205 | static int |
206 | read_printer_data() | |
207 | { | |
25a010c8 CN |
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", fd[0].fd, PRINTER_FILE); | |
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 data. */ | |
226 | retval = poll(fd, 1, 1000); | |
227 | ||
228 | if (retval && (fd[0].revents & POLLRDNORM)) { | |
229 | ||
230 | /* Read data from printer gadget driver. */ | |
231 | bytes_read = read(fd[0].fd, buf, BUF_SIZE); | |
232 | ||
233 | if (bytes_read < 0) { | |
234 | printf("Error %d reading from %s\n", | |
235 | fd[0].fd, PRINTER_FILE); | |
236 | close(fd[0].fd); | |
237 | return(-1); | |
238 | } else if (bytes_read > 0) { | |
239 | /* Write data to standard OUTPUT (stdout). */ | |
240 | fwrite(buf, 1, bytes_read, stdout); | |
241 | fflush(stdout); | |
242 | } | |
243 | ||
244 | } | |
245 | ||
246 | } | |
247 | ||
248 | /* Close the device file. */ | |
249 | close(fd[0].fd); | |
250 | ||
251 | return 0; | |
d80b5005 | 252 | } |
25a010c8 CN |
253 | |
254 | ||
d80b5005 MCC |
255 | static int |
256 | write_printer_data() | |
257 | { | |
25a010c8 CN |
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", fd[0].fd, PRINTER_FILE); | |
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 INPUT (stdin). */ | |
274 | int bytes_read = fread(buf, 1, BUF_SIZE, stdin); | |
275 | ||
276 | if (!bytes_read) { | |
277 | break; | |
278 | } | |
279 | ||
280 | while (bytes_read) { | |
281 | ||
282 | /* Wait for up to 1 second to sent data. */ | |
283 | retval = poll(fd, 1, 1000); | |
284 | ||
285 | /* Write data to printer gadget driver. */ | |
286 | if (retval && (fd[0].revents & POLLWRNORM)) { | |
287 | retval = write(fd[0].fd, buf, bytes_read); | |
288 | if (retval < 0) { | |
289 | printf("Error %d writing to %s\n", | |
290 | fd[0].fd, | |
291 | PRINTER_FILE); | |
292 | close(fd[0].fd); | |
293 | return(-1); | |
294 | } else { | |
295 | bytes_read -= retval; | |
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; | |
d80b5005 | 311 | } |
25a010c8 CN |
312 | |
313 | ||
d80b5005 MCC |
314 | static int |
315 | read_NB_printer_data() | |
316 | { | |
25a010c8 CN |
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_NONBLOCK); | |
323 | if (fd < 0) { | |
324 | printf("Error %d opening %s\n", fd, PRINTER_FILE); | |
325 | close(fd); | |
326 | return(-1); | |
327 | } | |
328 | ||
329 | while (1) { | |
330 | /* Read data from printer gadget driver. */ | |
331 | bytes_read = read(fd, buf, BUF_SIZE); | |
332 | if (bytes_read <= 0) { | |
333 | break; | |
334 | } | |
335 | ||
336 | /* Write data to standard OUTPUT (stdout). */ | |
337 | fwrite(buf, 1, bytes_read, stdout); | |
338 | fflush(stdout); | |
339 | } | |
340 | ||
341 | /* Close the device file. */ | |
342 | close(fd); | |
343 | ||
344 | return 0; | |
d80b5005 | 345 | } |
25a010c8 CN |
346 | |
347 | ||
d80b5005 MCC |
348 | static int |
349 | get_printer_status() | |
350 | { | |
25a010c8 CN |
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", fd, PRINTER_FILE); | |
358 | close(fd); | |
359 | return(-1); | |
360 | } | |
361 | ||
362 | /* Make the IOCTL call. */ | |
363 | retval = ioctl(fd, GADGET_GET_PRINTER_STATUS); | |
364 | if (retval < 0) { | |
365 | fprintf(stderr, "ERROR: Failed to set printer status\n"); | |
366 | return(-1); | |
367 | } | |
368 | ||
369 | /* Close the device file. */ | |
370 | close(fd); | |
371 | ||
372 | return(retval); | |
d80b5005 | 373 | } |
25a010c8 CN |
374 | |
375 | ||
d80b5005 MCC |
376 | static int |
377 | set_printer_status(unsigned char buf, int clear_printer_status_bit) | |
378 | { | |
25a010c8 CN |
379 | int retval; |
380 | int fd; | |
381 | ||
382 | retval = get_printer_status(); | |
383 | if (retval < 0) { | |
384 | fprintf(stderr, "ERROR: Failed to get printer status\n"); | |
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", fd, PRINTER_FILE); | |
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_STATUS, (unsigned char)retval)) { | |
405 | fprintf(stderr, "ERROR: Failed to set printer status\n"); | |
406 | return(-1); | |
407 | } | |
408 | ||
409 | /* Close the device file. */ | |
410 | close(fd); | |
411 | ||
412 | return 0; | |
d80b5005 | 413 | } |
25a010c8 CN |
414 | |
415 | ||
d80b5005 MCC |
416 | static int |
417 | display_printer_status() | |
418 | { | |
25a010c8 CN |
419 | char printer_status; |
420 | ||
421 | printer_status = get_printer_status(); | |
422 | if (printer_status < 0) { | |
423 | fprintf(stderr, "ERROR: Failed to get printer status\n"); | |
424 | return(-1); | |
425 | } | |
426 | ||
427 | printf("Printer status is:\n"); | |
428 | if (printer_status & PRINTER_SELECTED) { | |
429 | printf(" Printer is Selected\n"); | |
430 | } else { | |
431 | printf(" Printer is NOT Selected\n"); | |
432 | } | |
433 | if (printer_status & PRINTER_PAPER_EMPTY) { | |
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); | |
d80b5005 | 445 | } |
25a010c8 CN |
446 | |
447 | ||
d80b5005 MCC |
448 | int |
449 | main(int argc, char *argv[]) | |
450 | { | |
25a010c8 CN |
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_status")) { | |
467 | if (display_printer_status()) { | |
468 | retval = 1; | |
469 | } | |
470 | ||
471 | } else if (!strcmp(argv[i], "-paper_loaded")) { | |
472 | if (set_printer_status(PRINTER_PAPER_EMPTY, 1)) { | |
473 | retval = 1; | |
474 | } | |
475 | ||
476 | } else if (!strcmp(argv[i], "-paper_out")) { | |
477 | if (set_printer_status(PRINTER_PAPER_EMPTY, 0)) { | |
478 | retval = 1; | |
479 | } | |
480 | ||
481 | } else if (!strcmp(argv[i], "-selected")) { | |
482 | if (set_printer_status(PRINTER_SELECTED, 0)) { | |
483 | retval = 1; | |
484 | } | |
485 | ||
486 | } else if (!strcmp(argv[i], "-not_selected")) { | |
487 | if (set_printer_status(PRINTER_SELECTED, 1)) { | |
488 | retval = 1; | |
489 | } | |
490 | ||
491 | } else if (!strcmp(argv[i], "-error")) { | |
492 | if (set_printer_status(PRINTER_NOT_ERROR, 1)) { | |
493 | retval = 1; | |
494 | } | |
495 | ||
496 | } else if (!strcmp(argv[i], "-no_error")) { | |
497 | if (set_printer_status(PRINTER_NOT_ERROR, 0)) { | |
498 | retval = 1; | |
499 | } | |
500 | ||
501 | } else if (!strcmp(argv[i], "-read_data")) { | |
502 | if (read_printer_data()) { | |
503 | retval = 1; | |
504 | } | |
505 | ||
506 | } else if (!strcmp(argv[i], "-write_data")) { | |
507 | if (write_printer_data()) { | |
508 | retval = 1; | |
509 | } | |
510 | ||
511 | } else if (!strcmp(argv[i], "-NB_read_data")) { | |
512 | if (read_NB_printer_data()) { | |
513 | retval = 1; | |
514 | } | |
515 | ||
516 | } else { | |
517 | usage(argv[i]); | |
518 | retval = 1; | |
519 | } | |
520 | } | |
521 | ||
522 | exit(retval); | |
d80b5005 | 523 | } |