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1 | /* | |
2 | * This file is part of the sigrok project. | |
3 | * | |
4 | * Copyright (C) 2010 Sven Peter <sven@fail0verflow.com> | |
5 | * Copyright (C) 2010 Haxx Enterprises <bushing@gmail.com> | |
6 | * All rights reserved. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or | |
9 | * without modification, are permitted provided that the following | |
10 | * conditions are met: | |
11 | * | |
12 | * * Redistributions of source code must retain the above copyright notice, | |
13 | * this list of conditions and the following disclaimer. | |
14 | * | |
15 | * * Redistributions in binary form must reproduce the above copyright notice, | |
16 | * this list of conditions and the following disclaimer in the documentation | |
17 | * and/or other materials provided with the distribution. | |
18 | * | |
19 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
20 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE | |
23 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF | |
29 | * THE POSSIBILITY OF SUCH DAMAGE. | |
30 | */ | |
31 | ||
32 | #include <assert.h> | |
33 | #include "analyzer.h" | |
34 | #include "gl_usb.h" | |
35 | ||
36 | enum { | |
37 | HARD_DATA_CHECK_SUM = 0x00, | |
38 | PASS_WORD, | |
39 | ||
40 | DEVICE_ID0 = 0x10, | |
41 | DEVICE_ID1, | |
42 | ||
43 | START_STATUS = 0x20, | |
44 | DEVICE_STATUS = 0x21, | |
45 | FREQUENCY_REG0 = 0x30, | |
46 | FREQUENCY_REG1, | |
47 | FREQUENCY_REG2, | |
48 | FREQUENCY_REG3, | |
49 | FREQUENCY_REG4, | |
50 | MEMORY_LENGTH, | |
51 | CLOCK_SOURCE, | |
52 | ||
53 | TRIGGER_STATUS0 = 0x40, | |
54 | TRIGGER_STATUS1, | |
55 | TRIGGER_STATUS2, | |
56 | TRIGGER_STATUS3, | |
57 | TRIGGER_STATUS4, | |
58 | TRIGGER_STATUS5, | |
59 | TRIGGER_STATUS6, | |
60 | TRIGGER_STATUS7, | |
61 | TRIGGER_STATUS8, | |
62 | ||
63 | TRIGGER_COUNT0 = 0x50, | |
64 | TRIGGER_COUNT1, | |
65 | ||
66 | TRIGGER_LEVEL0 = 0x55, | |
67 | TRIGGER_LEVEL1, | |
68 | TRIGGER_LEVEL2, | |
69 | TRIGGER_LEVEL3, | |
70 | ||
71 | RAMSIZE_TRIGGERBAR_ADDRESS0 = 0x60, | |
72 | RAMSIZE_TRIGGERBAR_ADDRESS1, | |
73 | RAMSIZE_TRIGGERBAR_ADDRESS2, | |
74 | TRIGGERBAR_ADDRESS0, | |
75 | TRIGGERBAR_ADDRESS1, | |
76 | TRIGGERBAR_ADDRESS2, | |
77 | DONT_CARE_TRIGGERBAR, | |
78 | ||
79 | FILTER_ENABLE = 0x70, | |
80 | FILTER_STATUS, | |
81 | ||
82 | ENABLE_DELAY_TIME0 = 0x7a, | |
83 | ENABLE_DELAY_TIME1, | |
84 | ||
85 | ENABLE_INSERT_DATA0 = 0x80, | |
86 | ENABLE_INSERT_DATA1, | |
87 | ENABLE_INSERT_DATA2, | |
88 | ENABLE_INSERT_DATA3, | |
89 | COMPRESSION_TYPE0, | |
90 | COMPRESSION_TYPE1, | |
91 | ||
92 | TRIGGER_ADDRESS0 = 0x90, | |
93 | TRIGGER_ADDRESS1, | |
94 | TRIGGER_ADDRESS2, | |
95 | ||
96 | NOW_ADDRESS0 = 0x96, | |
97 | NOW_ADDRESS1, | |
98 | NOW_ADDRESS2, | |
99 | ||
100 | STOP_ADDRESS0 = 0x9b, | |
101 | STOP_ADDRESS1, | |
102 | STOP_ADDRESS2, | |
103 | ||
104 | READ_RAM_STATUS = 0xa0, | |
105 | }; | |
106 | ||
107 | static int g_trigger_status[9] = { 0 }; | |
108 | static int g_trigger_count = 1; | |
109 | static int g_filter_status[8] = { 0 }; | |
110 | static int g_filter_enable = 0; | |
111 | ||
112 | static int g_freq_value = 100; | |
113 | static int g_freq_scale = FREQ_SCALE_MHZ; | |
114 | static int g_memory_size = MEMORY_SIZE_512K; | |
115 | static int g_ramsize_triggerbar_addr = 0x80000 >> 2; | |
116 | static int g_triggerbar_addr = 0x3fe; | |
117 | static int g_compression = COMPRESSION_NONE; | |
118 | ||
119 | /* Maybe unk specifies an "endpoint" or "register" of sorts. */ | |
120 | static int analyzer_write_status(libusb_device_handle *devh, unsigned char unk, | |
121 | unsigned char flags) | |
122 | { | |
123 | assert(unk <= 3); | |
124 | return gl_reg_write(devh, START_STATUS, unk << 6 | flags); | |
125 | } | |
126 | ||
127 | static int __analyzer_set_freq(libusb_device_handle *devh, int freq, int scale) | |
128 | { | |
129 | int reg0 = 0, divisor = 0, reg2 = 0; | |
130 | ||
131 | switch (scale) { | |
132 | case FREQ_SCALE_MHZ: /* MHz */ | |
133 | if (freq >= 100 && freq <= 200) { | |
134 | reg0 = freq * 0.1; | |
135 | divisor = 1; | |
136 | reg2 = 0; | |
137 | break; | |
138 | } | |
139 | if (freq >= 50 && freq < 100) { | |
140 | reg0 = freq * 0.2; | |
141 | divisor = 2; | |
142 | reg2 = 0; | |
143 | break; | |
144 | } | |
145 | if (freq >= 10 && freq < 50) { | |
146 | if (freq == 25) { | |
147 | reg0 = 25; | |
148 | divisor = 5; | |
149 | reg2 = 1; | |
150 | break; | |
151 | } else { | |
152 | reg0 = freq * 0.5; | |
153 | divisor = 5; | |
154 | reg2 = 1; | |
155 | break; | |
156 | } | |
157 | } | |
158 | if (freq >= 2 && freq < 10) { | |
159 | divisor = 5; | |
160 | reg0 = freq * 2; | |
161 | reg2 = 2; | |
162 | break; | |
163 | } | |
164 | if (freq == 1) { | |
165 | divisor = 5; | |
166 | reg2 = 16; | |
167 | reg0 = 5; | |
168 | break; | |
169 | } | |
170 | divisor = 5; | |
171 | reg0 = 5; | |
172 | reg2 = 64; | |
173 | break; | |
174 | case FREQ_SCALE_HZ: /* Hz */ | |
175 | if (freq >= 500 && freq < 1000) { | |
176 | reg0 = freq * 0.01; | |
177 | divisor = 10; | |
178 | reg2 = 64; | |
179 | break; | |
180 | } | |
181 | if (freq >= 300 && freq < 500) { | |
182 | reg0 = freq * 0.005 * 8; | |
183 | divisor = 5; | |
184 | reg2 = 67; | |
185 | break; | |
186 | } | |
187 | if (freq >= 100 && freq < 300) { | |
188 | reg0 = freq * 0.005 * 16; | |
189 | divisor = 5; | |
190 | reg2 = 68; | |
191 | break; | |
192 | } | |
193 | divisor = 5; | |
194 | reg0 = 5; | |
195 | reg2 = 64; | |
196 | break; | |
197 | case FREQ_SCALE_KHZ: /* kHz */ | |
198 | if (freq >= 500 && freq < 1000) { | |
199 | reg0 = freq * 0.01; | |
200 | divisor = 5; | |
201 | reg2 = 17; | |
202 | break; | |
203 | } | |
204 | if (freq >= 100 && freq < 500) { | |
205 | reg0 = freq * 0.05; | |
206 | divisor = 5; | |
207 | reg2 = 32; | |
208 | break; | |
209 | } | |
210 | if (freq >= 50 && freq < 100) { | |
211 | reg0 = freq * 0.1; | |
212 | divisor = 5; | |
213 | reg2 = 33; | |
214 | break; | |
215 | } | |
216 | if (freq >= 10 && freq < 50) { | |
217 | if (freq == 25) { | |
218 | reg0 = 25; | |
219 | divisor = 5; | |
220 | reg2 = 49; | |
221 | break; | |
222 | } | |
223 | reg0 = freq * 0.5; | |
224 | divisor = 5; | |
225 | reg2 = 48; | |
226 | break; | |
227 | } | |
228 | if (freq >= 2 && freq < 10) { | |
229 | divisor = 5; | |
230 | reg0 = freq * 2; | |
231 | reg2 = 50; | |
232 | break; | |
233 | } | |
234 | divisor = 5; | |
235 | reg0 = 5; | |
236 | reg2 = 64; | |
237 | break; | |
238 | default: | |
239 | divisor = 5; | |
240 | reg0 = 5; | |
241 | reg2 = 64; | |
242 | break; | |
243 | } | |
244 | if (gl_reg_write(devh, FREQUENCY_REG0, divisor) < 0) | |
245 | return -1; /* Divisor maybe? */ | |
246 | ||
247 | if (gl_reg_write(devh, FREQUENCY_REG1, reg0) < 0) | |
248 | return -1; /* 10 / 0.2 */ | |
249 | ||
250 | if (gl_reg_write(devh, FREQUENCY_REG2, 0x02) < 0) | |
251 | return -1; /* Always 2 */ | |
252 | ||
253 | if (gl_reg_write(devh, FREQUENCY_REG4, reg2) < 0) | |
254 | return -1; | |
255 | ||
256 | return 0; | |
257 | } | |
258 | ||
259 | static void __analyzer_set_ramsize_trigger_address(libusb_device_handle *devh, | |
260 | unsigned int address) | |
261 | { | |
262 | gl_reg_write(devh, RAMSIZE_TRIGGERBAR_ADDRESS0, (address >> 0) & 0xFF); | |
263 | gl_reg_write(devh, RAMSIZE_TRIGGERBAR_ADDRESS1, (address >> 8) & 0xFF); | |
264 | gl_reg_write(devh, RAMSIZE_TRIGGERBAR_ADDRESS2, (address >> 16) & 0xFF); | |
265 | } | |
266 | ||
267 | static void __analyzer_set_triggerbar_address(libusb_device_handle *devh, | |
268 | unsigned int address) | |
269 | { | |
270 | gl_reg_write(devh, TRIGGERBAR_ADDRESS0, (address >> 0) & 0xFF); | |
271 | gl_reg_write(devh, TRIGGERBAR_ADDRESS1, (address >> 8) & 0xFF); | |
272 | gl_reg_write(devh, TRIGGERBAR_ADDRESS2, (address >> 16) & 0xFF); | |
273 | } | |
274 | ||
275 | static void __analyzer_set_compression(libusb_device_handle *devh, | |
276 | unsigned int type) | |
277 | { | |
278 | gl_reg_write(devh, COMPRESSION_TYPE0, (type >> 0) & 0xFF); | |
279 | gl_reg_write(devh, COMPRESSION_TYPE1, (type >> 8) & 0xFF); | |
280 | } | |
281 | ||
282 | static void __analyzer_set_trigger_count(libusb_device_handle *devh, | |
283 | unsigned int count) | |
284 | { | |
285 | gl_reg_write(devh, TRIGGER_COUNT0, (count >> 0) & 0xFF); | |
286 | gl_reg_write(devh, TRIGGER_COUNT1, (count >> 8) & 0xFF); | |
287 | } | |
288 | ||
289 | static void analyzer_write_enable_insert_data(libusb_device_handle *devh) | |
290 | { | |
291 | gl_reg_write(devh, ENABLE_INSERT_DATA0, 0x12); | |
292 | gl_reg_write(devh, ENABLE_INSERT_DATA1, 0x34); | |
293 | gl_reg_write(devh, ENABLE_INSERT_DATA2, 0x56); | |
294 | gl_reg_write(devh, ENABLE_INSERT_DATA3, 0x78); | |
295 | } | |
296 | ||
297 | static void analyzer_set_filter(libusb_device_handle *devh) | |
298 | { | |
299 | int i; | |
300 | gl_reg_write(devh, FILTER_ENABLE, g_filter_enable); | |
301 | for (i = 0; i < 8; i++) | |
302 | gl_reg_write(devh, FILTER_STATUS + i, g_filter_status[i]); | |
303 | } | |
304 | ||
305 | void analyzer_reset(libusb_device_handle *devh) | |
306 | { | |
307 | analyzer_write_status(devh, 3, STATUS_FLAG_NONE); // reset device | |
308 | analyzer_write_status(devh, 3, STATUS_FLAG_RESET); // reset device | |
309 | } | |
310 | ||
311 | void analyzer_initialize(libusb_device_handle *devh) | |
312 | { | |
313 | analyzer_write_status(devh, 1, STATUS_FLAG_NONE); | |
314 | analyzer_write_status(devh, 1, STATUS_FLAG_INIT); | |
315 | analyzer_write_status(devh, 1, STATUS_FLAG_NONE); | |
316 | } | |
317 | ||
318 | void analyzer_wait(libusb_device_handle *devh, int set, int unset) | |
319 | { | |
320 | int status; | |
321 | while (1) { | |
322 | status = gl_reg_read(devh, DEVICE_STATUS); | |
323 | if ((status & set) && ((status & unset) == 0)) | |
324 | return; | |
325 | } | |
326 | } | |
327 | ||
328 | void analyzer_read_start(libusb_device_handle *devh) | |
329 | { | |
330 | int i; | |
331 | ||
332 | analyzer_write_status(devh, 3, STATUS_FLAG_20 | STATUS_FLAG_READ); | |
333 | ||
334 | for (i = 0; i < 8; i++) | |
335 | (void)gl_reg_read(devh, READ_RAM_STATUS); | |
336 | } | |
337 | ||
338 | int analyzer_read_data(libusb_device_handle *devh, void *buffer, | |
339 | unsigned int size) | |
340 | { | |
341 | return gl_read_bulk(devh, buffer, size); | |
342 | } | |
343 | ||
344 | void analyzer_read_stop(libusb_device_handle *devh) | |
345 | { | |
346 | analyzer_write_status(devh, 3, STATUS_FLAG_20); | |
347 | analyzer_write_status(devh, 3, STATUS_FLAG_NONE); | |
348 | } | |
349 | ||
350 | void analyzer_start(libusb_device_handle *devh) | |
351 | { | |
352 | analyzer_write_status(devh, 1, STATUS_FLAG_NONE); | |
353 | analyzer_write_status(devh, 1, STATUS_FLAG_INIT); | |
354 | analyzer_write_status(devh, 1, STATUS_FLAG_NONE); | |
355 | analyzer_write_status(devh, 1, STATUS_FLAG_GO); | |
356 | } | |
357 | ||
358 | void analyzer_configure(libusb_device_handle *devh) | |
359 | { | |
360 | int i; | |
361 | ||
362 | /* Write_Start_Status */ | |
363 | analyzer_write_status(devh, 1, STATUS_FLAG_RESET); | |
364 | analyzer_write_status(devh, 1, STATUS_FLAG_NONE); | |
365 | ||
366 | /* Start_Config_Outside_Device ? */ | |
367 | analyzer_write_status(devh, 1, STATUS_FLAG_INIT); | |
368 | analyzer_write_status(devh, 1, STATUS_FLAG_NONE); | |
369 | ||
370 | /* SetData_To_Frequence_Reg */ | |
371 | __analyzer_set_freq(devh, g_freq_value, g_freq_scale); | |
372 | ||
373 | /* SetMemory_Length */ | |
374 | gl_reg_write(devh, MEMORY_LENGTH, g_memory_size); | |
375 | ||
376 | /* Sele_Inside_Outside_Clock */ | |
377 | gl_reg_write(devh, CLOCK_SOURCE, 0x03); | |
378 | ||
379 | /* Set_Trigger_Status */ | |
380 | for (i = 0; i < 9; i++) | |
381 | gl_reg_write(devh, TRIGGER_STATUS0 + i, g_trigger_status[i]); | |
382 | ||
383 | __analyzer_set_trigger_count(devh, g_trigger_count); | |
384 | ||
385 | /* Set_Trigger_Level */ | |
386 | gl_reg_write(devh, TRIGGER_LEVEL0, 0x31); | |
387 | gl_reg_write(devh, TRIGGER_LEVEL1, 0x31); | |
388 | gl_reg_write(devh, TRIGGER_LEVEL2, 0x31); | |
389 | gl_reg_write(devh, TRIGGER_LEVEL3, 0x31); | |
390 | ||
391 | /* Size of actual memory >> 2 */ | |
392 | __analyzer_set_ramsize_trigger_address(devh, g_ramsize_triggerbar_addr); | |
393 | __analyzer_set_triggerbar_address(devh, g_triggerbar_addr); | |
394 | ||
395 | /* Set_Dont_Care_TriggerBar */ | |
396 | gl_reg_write(devh, DONT_CARE_TRIGGERBAR, 0x01); | |
397 | ||
398 | /* Enable_Status */ | |
399 | analyzer_set_filter(devh); | |
400 | ||
401 | /* Set_Enable_Delay_Time */ | |
402 | gl_reg_write(devh, 0x7a, 0x00); | |
403 | gl_reg_write(devh, 0x7b, 0x00); | |
404 | analyzer_write_enable_insert_data(devh); | |
405 | __analyzer_set_compression(devh, g_compression); | |
406 | } | |
407 | ||
408 | void analyzer_add_trigger(int channel, int type) | |
409 | { | |
410 | int i; | |
411 | ||
412 | if ((channel & 0xf) >= 8) | |
413 | return; | |
414 | ||
415 | if (type == TRIGGER_HIGH || type == TRIGGER_LOW) { | |
416 | if (channel & CHANNEL_A) | |
417 | i = 0; | |
418 | else if (channel & CHANNEL_B) | |
419 | i = 2; | |
420 | else if (channel & CHANNEL_C) | |
421 | i = 4; | |
422 | else if (channel & CHANNEL_D) | |
423 | i = 6; | |
424 | else | |
425 | return; | |
426 | if ((channel & 0xf) >= 4) { | |
427 | i++; | |
428 | channel -= 4; | |
429 | } | |
430 | g_trigger_status[i] |= | |
431 | 1 << ((2 * channel) + (type == TRIGGER_LOW ? 1 : 0)); | |
432 | } else { | |
433 | if (type == TRIGGER_POSEDGE) | |
434 | g_trigger_status[8] = 0x40; | |
435 | else if (type == TRIGGER_NEGEDGE) | |
436 | g_trigger_status[8] = 0x80; | |
437 | else | |
438 | g_trigger_status[8] = 0xc0; | |
439 | ||
440 | /* FIXME: Just guessed the index; need to verify. */ | |
441 | if (channel & CHANNEL_B) | |
442 | g_trigger_status[8] += 8; | |
443 | else if (channel & CHANNEL_C) | |
444 | g_trigger_status[8] += 16; | |
445 | else if (channel & CHANNEL_D) | |
446 | g_trigger_status[8] += 24; | |
447 | g_trigger_status[8] += channel % 8; | |
448 | } | |
449 | } | |
450 | ||
451 | void analyzer_add_filter(int channel, int type) | |
452 | { | |
453 | int i; | |
454 | ||
455 | if (type != FILTER_HIGH && type != FILTER_LOW) | |
456 | return; | |
457 | if ((channel & 0xf) >= 8) | |
458 | return; | |
459 | ||
460 | if (channel & CHANNEL_A) | |
461 | i = 0; | |
462 | else if (channel & CHANNEL_B) | |
463 | i = 2; | |
464 | else if (channel & CHANNEL_C) | |
465 | i = 4; | |
466 | else if (channel & CHANNEL_D) | |
467 | i = 6; | |
468 | else | |
469 | return; | |
470 | ||
471 | if ((channel & 0xf) >= 4) { | |
472 | i++; | |
473 | channel -= 4; | |
474 | } | |
475 | ||
476 | g_filter_status[i] |= | |
477 | 1 << ((2 * channel) + (type == FILTER_LOW ? 1 : 0)); | |
478 | ||
479 | g_filter_enable = 1; | |
480 | } | |
481 | ||
482 | void analyzer_set_trigger_count(int count) | |
483 | { | |
484 | g_trigger_count = count; | |
485 | } | |
486 | ||
487 | void analyzer_set_freq(int freq, int scale) | |
488 | { | |
489 | g_freq_value = freq; | |
490 | g_freq_scale = scale; | |
491 | } | |
492 | ||
493 | void analyzer_set_memory_size(unsigned int size) | |
494 | { | |
495 | g_memory_size = size; | |
496 | } | |
497 | ||
498 | void analyzer_set_ramsize_trigger_address(unsigned int address) | |
499 | { | |
500 | g_ramsize_triggerbar_addr = address; | |
501 | } | |
502 | ||
503 | void analyzer_set_triggerbar_address(unsigned int address) | |
504 | { | |
505 | g_triggerbar_addr = address; | |
506 | } | |
507 | ||
508 | unsigned int analyzer_read_id(libusb_device_handle *devh) | |
509 | { | |
510 | return gl_reg_read(devh, DEVICE_ID1) << 8 | gl_reg_read(devh, | |
511 | DEVICE_ID0); | |
512 | } | |
513 | ||
514 | unsigned int analyzer_get_stop_address(libusb_device_handle *devh) | |
515 | { | |
516 | return gl_reg_read(devh, STOP_ADDRESS2) << 16 | gl_reg_read(devh, | |
517 | STOP_ADDRESS1) << 8 | gl_reg_read(devh, STOP_ADDRESS0); | |
518 | } | |
519 | ||
520 | unsigned int analyzer_get_now_address(libusb_device_handle *devh) | |
521 | { | |
522 | return gl_reg_read(devh, NOW_ADDRESS2) << 16 | gl_reg_read(devh, | |
523 | NOW_ADDRESS1) << 8 | gl_reg_read(devh, NOW_ADDRESS0); | |
524 | } | |
525 | ||
526 | unsigned int analyzer_get_trigger_address(libusb_device_handle *devh) | |
527 | { | |
528 | return gl_reg_read(devh, TRIGGER_ADDRESS2) << 16 | gl_reg_read(devh, | |
529 | TRIGGER_ADDRESS1) << 8 | gl_reg_read(devh, TRIGGER_ADDRESS0); | |
530 | } | |
531 | ||
532 | void analyzer_set_compression(unsigned int type) | |
533 | { | |
534 | g_compression = type; | |
535 | } | |
536 | ||
537 | void analyzer_wait_button(libusb_device_handle *devh) | |
538 | { | |
539 | analyzer_wait(devh, STATUS_BUTTON_PRESSED, 0); | |
540 | } | |
541 | ||
542 | void analyzer_wait_data(libusb_device_handle *devh) | |
543 | { | |
544 | analyzer_wait(devh, STATUS_READY | 8, STATUS_BUSY); | |
545 | } | |
546 | ||
547 | int analyzer_decompress(void *input, unsigned int input_len, void *output, | |
548 | unsigned int output_len) | |
549 | { | |
550 | unsigned char *in = input; | |
551 | unsigned char *out = output; | |
552 | unsigned int A, B, C, count; | |
553 | unsigned int written = 0; | |
554 | ||
555 | while (input_len > 0) { | |
556 | A = *in++; | |
557 | B = *in++; | |
558 | C = *in++; | |
559 | count = (*in++) + 1; | |
560 | ||
561 | if (count > output_len) | |
562 | count = output_len; | |
563 | output_len -= count; | |
564 | written += count; | |
565 | ||
566 | while (count--) { | |
567 | *out++ = A; | |
568 | *out++ = B; | |
569 | *out++ = C; | |
570 | *out++ = 0; /* Channel D */ | |
571 | } | |
572 | ||
573 | input_len -= 4; | |
574 | if (output_len == 0) | |
575 | break; | |
576 | } | |
577 | ||
578 | return written; | |
579 | } |