aboutsummaryrefslogtreecommitdiff
path: root/src/jtag/ftdi2232.c
blob: c90cc2f94185728437a97632932ee010dc14ade4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
/***************************************************************************
 *   Copyright (C) 2004 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/* project specific includes */
#include "log.h"
#include "types.h"
#include "jtag.h"
#include "configuration.h"
#include "command.h"

/* system includes */
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <usb.h>
#include <ftdi.h>

#include <sys/time.h>
#include <time.h>

/* enable this to debug io latency
 */
#if 0
#define _DEBUG_USB_IO_
#endif

int ftdi2232_execute_queue(void);

int ftdi2232_speed(int speed);
int ftdi2232_register_commands(struct command_context_s *cmd_ctx);
int ftdi2232_init(void);
int ftdi2232_quit(void);

enum { FTDI2232_TRST = 0x10, FTDI2232_SRST = 0x40 };
static u8 discrete_output = 0x0 | FTDI2232_TRST | FTDI2232_SRST;
static struct ftdi_context ftdic;

static u8 *ftdi2232_buffer = NULL;
static int ftdi2232_buffer_size = 0;
static int ftdi2232_read_pointer = 0;
static int ftdi2232_expect_read = 0;
#define FTDI2232_BUFFER_SIZE	131072
#define BUFFER_ADD ftdi2232_buffer[ftdi2232_buffer_size++]
#define BUFFER_READ ftdi2232_buffer[ftdi2232_read_pointer++]

#define FTDI2232_SAVE_SIZE	1024

int ftdi2232_handle_vid_pid_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);

static u16 ftdi2232_vid = 0x0403;
static u16 ftdi2232_pid = 0x6010;

jtag_interface_t ftdi2232_interface = 
{
	
	.name = "ftdi2232",
	
	.execute_queue = ftdi2232_execute_queue,
	
	.support_statemove = 1,
	
	.speed = ftdi2232_speed,
	.register_commands = ftdi2232_register_commands,
	.init = ftdi2232_init,
	.quit = ftdi2232_quit,
};

int ftdi2232_speed(int speed)
{
	u8 buf[3];

	buf[0] = 0x86; /* command "set divisor" */
	buf[1] = speed & 0xff; /* valueL (0=6MHz, 1=3MHz, 2=1.5MHz, ...*/
	buf[2] = (speed >> 8) & 0xff; /* valueH */
	
	DEBUG("%2.2x %2.2x %2.2x", buf[0], buf[1], buf[2]);
	ftdi_write_data(&ftdic, buf, 3);

	return ERROR_OK;
}

int ftdi2232_register_commands(struct command_context_s *cmd_ctx)
{
	register_command(cmd_ctx, NULL, "ftdi2232_vid_pid", ftdi2232_handle_vid_pid_command,
		COMMAND_CONFIG, NULL);
	
	return ERROR_OK;
}

void ftdi2232_end_state(state)
{
	if (tap_move_map[state] != -1)
		end_state = state;
	else
	{
		ERROR("BUG: %i is not a valid end state", state);
		exit(-1);
	}
}

void ftdi2232_read_scan(enum scan_type type, u8* buffer, int scan_size)
{
	int num_bytes = ((scan_size + 7) / 8);
	int bits_left = scan_size;
	int cur_byte = 0;

	while(num_bytes-- > 1)
	{
		buffer[cur_byte] = BUFFER_READ;
		cur_byte++;
		bits_left -= 8;
	}

	buffer[cur_byte] = 0x0;

	if (bits_left > 1)
	{
		buffer[cur_byte] = BUFFER_READ >> 1;
	}

	buffer[cur_byte] = (buffer[cur_byte] | ((BUFFER_READ & 0x02) << 6)) >> (8 - bits_left);

}

void ftdi2232_debug_dump_buffer(void)
{
	int i;
	for (i = 0; i < ftdi2232_buffer_size; i++)
	{
		printf("%2.2x ", ftdi2232_buffer[i]);
		if (i % 16 == 15)
			printf("\n");
	}
	printf("\n");
	fflush(stdout);
}

int ftdi2232_send_and_recv(jtag_command_t *first, jtag_command_t *last)
{
	jtag_command_t *cmd;
	u8 *buffer;
	int scan_size;
	enum scan_type type;
	int retval;

	BUFFER_ADD = 0x87;	/* send immediate command */
	
	if (ftdi2232_buffer_size > FTDI2232_SAVE_SIZE)
	{
		ERROR("BUG: ftdi2232_buffer grew beyond %i byte (%i) - this is going to fail", FTDI2232_SAVE_SIZE,  ftdi2232_buffer_size);
	}

#ifdef _DEBUG_USB_IO_
	DEBUG("write buffer (size %i):", ftdi2232_buffer_size);
	ftdi2232_debug_dump_buffer();
#endif

	if ((retval = ftdi_write_data(&ftdic, ftdi2232_buffer, ftdi2232_buffer_size)) < 0)
	{
		ERROR("ftdi_write_data returned %i", retval);
		exit(-1);
	}

	if (ftdi2232_expect_read)
	{
		int timeout = 100;
		ftdi2232_buffer_size = 0;
		
		while ((ftdi2232_buffer_size < ftdi2232_expect_read) && timeout)
		{
			ftdi2232_buffer_size += ftdi_read_data(&ftdic, ftdi2232_buffer + ftdi2232_buffer_size, FTDI2232_BUFFER_SIZE - ftdi2232_buffer_size);
			timeout--;
		}

		if (ftdi2232_expect_read != ftdi2232_buffer_size)
		{
			ERROR("ftdi2232_expect_read (%i) != ftdi2232_buffer_size (%i) (%i retries)", ftdi2232_expect_read, ftdi2232_buffer_size, 100 - timeout);
			ftdi2232_debug_dump_buffer();

			exit(-1);
		}

#ifdef _DEBUG_USB_IO_
		DEBUG("read buffer (%i retries): %i bytes", 100 - timeout, ftdi2232_buffer_size);
		ftdi2232_debug_dump_buffer();	
#endif
	}

	ftdi2232_expect_read = 0;
	ftdi2232_read_pointer = 0;

	cmd = first;
	while (cmd != last)
	{
		switch (cmd->type)
		{
			case JTAG_SCAN:
				type = jtag_scan_type(cmd->cmd.scan);
				if (type != SCAN_OUT)
				{
					scan_size = jtag_scan_size(cmd->cmd.scan);
					buffer = calloc(CEIL(scan_size, 8), 1);
					ftdi2232_read_scan(type, buffer, scan_size);
					jtag_read_buffer(buffer, cmd->cmd.scan);
					free(buffer);
				}
				break;
			default:
				break;
		}
		cmd = cmd->next;
	}
	
	ftdi2232_buffer_size = 0;

	return ERROR_OK;
}

void ftdi2232_add_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size)
{
	int num_bytes = (scan_size + 7) / 8;
	int bits_left = scan_size;
	int cur_byte = 0;
	int last_bit;

	/* command "Clock Data to TMS/CS Pin (no Read)" */
	BUFFER_ADD = 0x4b;
	/* scan 7 bit */
	BUFFER_ADD = 0x6;
	/* TMS data bits */
	if (ir_scan)
	{
		BUFFER_ADD = TAP_MOVE(cur_state, TAP_SI);
		cur_state = TAP_SI;
	}
	else
	{
		BUFFER_ADD = TAP_MOVE(cur_state, TAP_SD);
		cur_state = TAP_SD;
	}
	//DEBUG("added TMS scan (no read)");

	/* add command for complete bytes */
	if (num_bytes > 1)
	{
		if (type == SCAN_IO)
		{
			/* Clock Data Bytes In and Out LSB First */
			BUFFER_ADD = 0x39;
			//DEBUG("added TDI bytes (io %i)", num_bytes);
		}
		else if (type == SCAN_OUT)
		{
			/* Clock Data Bytes Out on -ve Clock Edge LSB First (no Read) */
			BUFFER_ADD = 0x19;
			//DEBUG("added TDI bytes (o)");
		}
		else if (type == SCAN_IN)
		{
			/* Clock Data Bytes In on +ve Clock Edge LSB First (no Write) */
			BUFFER_ADD = 0x28;
			//DEBUG("added TDI bytes (i %i)", num_bytes);
		}
		BUFFER_ADD = (num_bytes-2) & 0xff;
		BUFFER_ADD = ((num_bytes-2) >> 8) & 0xff;
	}
	if (type != SCAN_IN)
	{
		/* add complete bytes */
		while(num_bytes-- > 1)
		{
			BUFFER_ADD = buffer[cur_byte];
			cur_byte++;
			bits_left -= 8;
		}
	}
	if (type == SCAN_IN)
	{
		bits_left -= 8 * (num_bytes - 1);
	}

	/* the most signifcant bit is scanned during TAP movement */
	if (type != SCAN_IN)
		last_bit = (buffer[cur_byte] >> (bits_left - 1)) & 0x1;
	else
		last_bit = 0;

	/* process remaining bits but the last one */
	if (bits_left > 1)
	{
		if (type == SCAN_IO)
		{
			/* Clock Data Bits In and Out LSB First */
			BUFFER_ADD = 0x3b;
			//DEBUG("added TDI bits (io) %i", bits_left - 1);
		}
		else if (type == SCAN_OUT)
		{
			/* Clock Data Bits Out on -ve Clock Edge LSB First (no Read) */
			BUFFER_ADD = 0x1b;
			//DEBUG("added TDI bits (o)");
		}
		else if (type == SCAN_IN)
		{
			/* Clock Data Bits In on +ve Clock Edge LSB First (no Write) */
			BUFFER_ADD = 0x2a;
			//DEBUG("added TDI bits (i %i)", bits_left - 1);
		}
		BUFFER_ADD = bits_left - 2;
		if (type != SCAN_IN)
			BUFFER_ADD = buffer[cur_byte];
	}

	/* move from Shift-IR/DR to end state */
	if (type != SCAN_OUT)
	{
		/* Clock Data to TMS/CS Pin with Read */
		BUFFER_ADD = 0x6b;
		//DEBUG("added TMS scan (read)");
	}
	else
	{
		/* Clock Data to TMS/CS Pin (no Read) */
		BUFFER_ADD = 0x4b;
		//DEBUG("added TMS scan (no read)");
	}
	BUFFER_ADD = 0x6;
	BUFFER_ADD = TAP_MOVE(cur_state, end_state) | (last_bit << 7);
	cur_state = end_state;

}

int ftdi2232_predict_scan_out(int scan_size, enum scan_type type)
{
	int predicted_size = 6;
	if (type == SCAN_IN)	/* only from device to host */
	{
		predicted_size += (CEIL(scan_size, 8) > 1) ? 3 : 0;
		predicted_size += ((scan_size - 1) % 8) ? 2 : 0;
	}
	else					/* host to device, or bidirectional */
	{
		predicted_size += (CEIL(scan_size, 8) > 1) ? (CEIL(scan_size, 8) + 3 - 1) : 0;
		predicted_size += ((scan_size - 1) % 8) ? 3 : 0;
	}

	return predicted_size;
}

int ftdi2232_predict_scan_in(int scan_size, enum scan_type type)
{
	int predicted_size = 0;
	
	if (type != SCAN_OUT)
	{
		/* complete bytes */
		predicted_size += (CEIL(scan_size, 8) > 1) ? (CEIL(scan_size, 8) - 1) : 0;
		/* remaining bits - 1 */
		predicted_size += ((scan_size - 1) % 8) ? 1 : 0;
		/* last bit (from TMS scan) */
		predicted_size += 1;
	}
	
	//DEBUG("scan_size: %i, predicted_size: %i", scan_size, predicted_size);

	return predicted_size;
}

int ftdi2232_execute_queue()
{
	jtag_command_t *cmd = jtag_command_queue; /* currently processed command */
	jtag_command_t *first_unsent = cmd;	/* next command that has to be sent */
	u8 *buffer;
	int scan_size;	/* size of IR or DR scan */
	enum scan_type type;
	int i;
	int predicted_size = 0;
	int require_send = 0;

	ftdi2232_buffer_size = 0;
	ftdi2232_expect_read = 0;

	while (cmd)
	{
		switch(cmd->type)
		{
			case JTAG_END_STATE:
				if (cmd->cmd.end_state->end_state != -1)
					ftdi2232_end_state(cmd->cmd.end_state->end_state);
				break;
			case JTAG_RESET:
				/* only send the maximum buffer size that FT2232C can handle */
				predicted_size = 3;
				if (ftdi2232_buffer_size + predicted_size + 1 > FTDI2232_SAVE_SIZE)
				{
					ftdi2232_send_and_recv(first_unsent, cmd);
					require_send = 0;
					first_unsent = cmd;
				}

				if (cmd->cmd.reset->trst == 1)
				{
					cur_state = TAP_TLR;
					discrete_output &= ~FTDI2232_TRST;
				}
				else if (cmd->cmd.reset->trst == 0)
				{
					discrete_output |= FTDI2232_TRST;
				}

				if (cmd->cmd.reset->srst == 1)
					discrete_output &= ~FTDI2232_SRST;
				else if (cmd->cmd.reset->srst == 0)
					discrete_output |= FTDI2232_SRST;
				/* command "set data bits low byte" */
				BUFFER_ADD = 0x80;
				/* value (TMS=1,TCK=0, TDI=0, TRST/SRST */
				BUFFER_ADD = 0x08 | discrete_output;
				/* dir (output=1), TCK/TDI/TMS=out, TDO=in, TRST/SRST=out */
				BUFFER_ADD = 0x0b | FTDI2232_SRST | FTDI2232_TRST;
				require_send = 1;
				break;
			case JTAG_RUNTEST:
				/* only send the maximum buffer size that FT2232C can handle */
				predicted_size = 0;
				if (cur_state != TAP_RTI)
					predicted_size += 3;
				predicted_size += 3 * CEIL(cmd->cmd.runtest->num_cycles, 7);
				if ((cmd->cmd.runtest->end_state != -1) && (cmd->cmd.runtest->end_state != TAP_RTI))
					predicted_size += 3;
				if ((cmd->cmd.runtest->end_state == -1) && (end_state != TAP_RTI))
					predicted_size += 3;
				if (ftdi2232_buffer_size + predicted_size + 1 > FTDI2232_SAVE_SIZE)
				{
					ftdi2232_send_and_recv(first_unsent, cmd);
					require_send = 0;
					first_unsent = cmd;
				}
				if (cur_state != TAP_RTI)
				{
					/* command "Clock Data to TMS/CS Pin (no Read)" */
					BUFFER_ADD = 0x4b;
					/* scan 7 bit */
					BUFFER_ADD = 0x6;
					/* TMS data bits */
					BUFFER_ADD = TAP_MOVE(cur_state, TAP_RTI);
					cur_state = TAP_RTI;
					require_send = 1;
				}
				i = cmd->cmd.runtest->num_cycles;
				while (i > 0)
				{
					/* command "Clock Data to TMS/CS Pin (no Read)" */
					BUFFER_ADD = 0x4b;
					/* scan 7 bit */
					BUFFER_ADD = (i > 7) ? 6 : (i - 1);
					/* TMS data bits */
					BUFFER_ADD = 0x0;
					cur_state = TAP_RTI;
					i -= (i > 7) ? 7 : i;
					//DEBUG("added TMS scan (no read)");
				}
				if (cmd->cmd.runtest->end_state != -1)
					ftdi2232_end_state(cmd->cmd.runtest->end_state);
				if (cur_state != end_state)
				{
					/* command "Clock Data to TMS/CS Pin (no Read)" */
					BUFFER_ADD = 0x4b;
					/* scan 7 bit */
					BUFFER_ADD = 0x6;
					/* TMS data bits */
					BUFFER_ADD = TAP_MOVE(cur_state, end_state);
					cur_state = end_state;
					//DEBUG("added TMS scan (no read)");
				}
				require_send = 1;
				break;
			case JTAG_STATEMOVE:
				/* only send the maximum buffer size that FT2232C can handle */
				predicted_size = 3;
				if (ftdi2232_buffer_size + predicted_size + 1 > FTDI2232_SAVE_SIZE)
				{
					ftdi2232_send_and_recv(first_unsent, cmd);
					require_send = 0;
					first_unsent = cmd;
				}
				if (cmd->cmd.statemove->end_state != -1)
					ftdi2232_end_state(cmd->cmd.statemove->end_state);
				/* command "Clock Data to TMS/CS Pin (no Read)" */
				BUFFER_ADD = 0x4b;
				/* scan 7 bit */
				BUFFER_ADD = 0x6;
				/* TMS data bits */
				BUFFER_ADD = TAP_MOVE(cur_state, end_state);
				//DEBUG("added TMS scan (no read)");
				cur_state = end_state;
				require_send = 1;
				break;
			case JTAG_SCAN:
				scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
				type = jtag_scan_type(cmd->cmd.scan);
				predicted_size = ftdi2232_predict_scan_out(scan_size, type);
				if (ftdi2232_buffer_size + predicted_size + 1 > FTDI2232_SAVE_SIZE)
				{
					ftdi2232_send_and_recv(first_unsent, cmd);
					require_send = 0;
					first_unsent = cmd;
				}
				ftdi2232_expect_read += ftdi2232_predict_scan_in(scan_size, type);
				//DEBUG("new read size: %i", ftdi2232_expect_read);
				if (cmd->cmd.scan->end_state != -1)
					ftdi2232_end_state(cmd->cmd.scan->end_state);
				ftdi2232_add_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size);
				require_send = 1;
				if (buffer)
					free(buffer);
				break;
			case JTAG_SLEEP:
				jtag_sleep(cmd->cmd.sleep->us);
				break;
			default:
				ERROR("BUG: unknown JTAG command type encountered");
				exit(-1);
		}
		cmd = cmd->next;
	}

	if (require_send > 0)
		ftdi2232_send_and_recv(first_unsent, cmd);

	return ERROR_OK;
}

int ftdi2232_init(void)
{
	if (ftdi_init(&ftdic) < 0)
		return ERROR_JTAG_INIT_FAILED;

	/* context, vendor id, product id */
	if (ftdi_usb_open(&ftdic, ftdi2232_vid, ftdi2232_pid) < 0)
	{
		ERROR("unable to open ftdi device: %s", ftdic.error_str);
		return ERROR_JTAG_INIT_FAILED;
	}

	if (ftdi_usb_reset(&ftdic) < 0)
	{
		ERROR("unable to reset ftdi device");
		return ERROR_JTAG_INIT_FAILED;
	}

	if (ftdi_set_latency_timer(&ftdic, 1) < 0)
	{
		ERROR("unable to set latency timer");
		return ERROR_JTAG_INIT_FAILED;
	}

	ftdi2232_buffer_size = 0;
	ftdi2232_buffer = malloc(FTDI2232_BUFFER_SIZE);

	ftdic.bitbang_mode = 0; /* Reset controller */
	ftdi_enable_bitbang(&ftdic, 0x0b | FTDI2232_SRST | FTDI2232_TRST); /* ctx, i/o mask (out=1, in=0) */

	ftdic.bitbang_mode = 2; /* MPSSE mode */
	ftdi_enable_bitbang(&ftdic, 0x0b | FTDI2232_SRST | FTDI2232_TRST); /* ctx, i/o mask (out=1, in=0) */
	
	if (ftdi_usb_purge_buffers(&ftdic) < 0)
	{
		ERROR("ftdi_purge_buffers: %s", ftdic.error_str);
		return ERROR_JTAG_INIT_FAILED;
	}

	/* initialize low byte for jtag */
	BUFFER_ADD = 0x80; /* command "set data bits low byte" */
	BUFFER_ADD = 0x08 | FTDI2232_SRST | FTDI2232_TRST; /* value (TMS=1,TCK=0, TDI=0, xRST high) */
	BUFFER_ADD = 0x0b | FTDI2232_SRST | FTDI2232_TRST; /* dir (output=1), TCK/TDI/TMS=out, TDO=in */
	BUFFER_ADD = 0x85; /* command "Disconnect TDI/DO to TDO/DI for Loopback" */
	ftdi2232_debug_dump_buffer();
	if (ftdi_write_data(&ftdic, ftdi2232_buffer, ftdi2232_buffer_size) != 4)
		return ERROR_JTAG_INIT_FAILED;

	ftdi2232_speed(jtag_speed);

	return ERROR_OK;
}

int ftdi2232_quit(void)
{
	ftdi_disable_bitbang(&ftdic);
	
	ftdi_usb_close(&ftdic);
	
	ftdi_deinit(&ftdic);

	free(ftdi2232_buffer);

	return ERROR_OK;
}

int ftdi2232_handle_vid_pid_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
	if (argc >= 2)
	{
		ftdi2232_vid = strtol(args[0], NULL, 0);
		ftdi2232_pid = strtol(args[1], NULL, 0);
	}
	else
	{
		WARNING("incomplete ftdi2232_vid_pid configuration directive");
	}
	
	return ERROR_OK;
}