aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/serial/cp210x.c
blob: 28af5acc3360c57beaad356f1b4aa016fc221810 (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
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
/*
 * Silicon Laboratories CP210x USB to RS232 serial adaptor driver
 *
 * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License version
 *	2 as published by the Free Software Foundation.
 *
 * Support to set flow control line levels using TIOCMGET and TIOCMSET
 * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
 * control thanks to Munir Nassar nassarmu@real-time.com
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/usb.h>
#include <linux/uaccess.h>
#include <linux/usb/serial.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.09"
#define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"

/*
 * Function Prototypes
 */
static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
static void cp210x_close(struct usb_serial_port *);
static void cp210x_get_termios(struct tty_struct *,
	struct usb_serial_port *port);
static void cp210x_get_termios_port(struct usb_serial_port *port,
	unsigned int *cflagp, unsigned int *baudp);
static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
							struct ktermios *);
static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
							struct ktermios*);
static int cp210x_tiocmget(struct tty_struct *);
static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
static int cp210x_tiocmset_port(struct usb_serial_port *port,
		unsigned int, unsigned int);
static void cp210x_break_ctl(struct tty_struct *, int);
static int cp210x_startup(struct usb_serial *);
static void cp210x_release(struct usb_serial *);
static void cp210x_dtr_rts(struct usb_serial_port *p, int on);

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
	{ USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
	{ USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
	{ USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
	{ USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
	{ USB_DEVICE(0x10C4, 0xEA80) }, /* Silicon Labs factory default */
	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
	{ USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
	{ USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
	{ USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
	{ USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
	{ USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
	{ USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
	{ } /* Terminating Entry */
};

MODULE_DEVICE_TABLE(usb, id_table);

struct cp210x_port_private {
	__u8			bInterfaceNumber;
};

static struct usb_serial_driver cp210x_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name = 	"cp210x",
	},
	.id_table		= id_table,
	.num_ports		= 1,
	.bulk_in_size		= 256,
	.bulk_out_size		= 256,
	.open			= cp210x_open,
	.close			= cp210x_close,
	.break_ctl		= cp210x_break_ctl,
	.set_termios		= cp210x_set_termios,
	.tiocmget 		= cp210x_tiocmget,
	.tiocmset		= cp210x_tiocmset,
	.attach			= cp210x_startup,
	.release		= cp210x_release,
	.dtr_rts		= cp210x_dtr_rts
};

static struct usb_serial_driver * const serial_drivers[] = {
	&cp210x_device, NULL
};

/* Config request types */
#define REQTYPE_HOST_TO_INTERFACE	0x41
#define REQTYPE_INTERFACE_TO_HOST	0xc1
#define REQTYPE_HOST_TO_DEVICE	0x40
#define REQTYPE_DEVICE_TO_HOST	0xc0

/* Config request codes */
#define CP210X_IFC_ENABLE	0x00
#define CP210X_SET_BAUDDIV	0x01
#define CP210X_GET_BAUDDIV	0x02
#define CP210X_SET_LINE_CTL	0x03
#define CP210X_GET_LINE_CTL	0x04
#define CP210X_SET_BREAK	0x05
#define CP210X_IMM_CHAR		0x06
#define CP210X_SET_MHS		0x07
#define CP210X_GET_MDMSTS	0x08
#define CP210X_SET_XON		0x09
#define CP210X_SET_XOFF		0x0A
#define CP210X_SET_EVENTMASK	0x0B
#define CP210X_GET_EVENTMASK	0x0C
#define CP210X_SET_CHAR		0x0D
#define CP210X_GET_CHARS	0x0E
#define CP210X_GET_PROPS	0x0F
#define CP210X_GET_COMM_STATUS	0x10
#define CP210X_RESET		0x11
#define CP210X_PURGE		0x12
#define CP210X_SET_FLOW		0x13
#define CP210X_GET_FLOW		0x14
#define CP210X_EMBED_EVENTS	0x15
#define CP210X_GET_EVENTSTATE	0x16
#define CP210X_SET_CHARS	0x19
#define CP210X_GET_BAUDRATE	0x1D
#define CP210X_SET_BAUDRATE	0x1E

/* CP210X_IFC_ENABLE */
#define UART_ENABLE		0x0001
#define UART_DISABLE		0x0000

/* CP210X_(SET|GET)_BAUDDIV */
#define BAUD_RATE_GEN_FREQ	0x384000

/* CP210X_(SET|GET)_LINE_CTL */
#define BITS_DATA_MASK		0X0f00
#define BITS_DATA_5		0X0500
#define BITS_DATA_6		0X0600
#define BITS_DATA_7		0X0700
#define BITS_DATA_8		0X0800
#define BITS_DATA_9		0X0900

#define BITS_PARITY_MASK	0x00f0
#define BITS_PARITY_NONE	0x0000
#define BITS_PARITY_ODD		0x0010
#define BITS_PARITY_EVEN	0x0020
#define BITS_PARITY_MARK	0x0030
#define BITS_PARITY_SPACE	0x0040

#define BITS_STOP_MASK		0x000f
#define BITS_STOP_1		0x0000
#define BITS_STOP_1_5		0x0001
#define BITS_STOP_2		0x0002

/* CP210X_SET_BREAK */
#define BREAK_ON		0x0001
#define BREAK_OFF		0x0000

/* CP210X_(SET_MHS|GET_MDMSTS) */
#define CONTROL_DTR		0x0001
#define CONTROL_RTS		0x0002
#define CONTROL_CTS		0x0010
#define CONTROL_DSR		0x0020
#define CONTROL_RING		0x0040
#define CONTROL_DCD		0x0080
#define CONTROL_WRITE_DTR	0x0100
#define CONTROL_WRITE_RTS	0x0200

/*
 * cp210x_get_config
 * Reads from the CP210x configuration registers
 * 'size' is specified in bytes.
 * 'data' is a pointer to a pre-allocated array of integers large
 * enough to hold 'size' bytes (with 4 bytes to each integer)
 */
static int cp210x_get_config(struct usb_serial_port *port, u8 request,
		unsigned int *data, int size)
{
	struct usb_serial *serial = port->serial;
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	__le32 *buf;
	int result, i, length;

	/* Number of integers required to contain the array */
	length = (((size - 1) | 3) + 1)/4;

	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
	if (!buf) {
		dev_err(&port->dev, "%s - out of memory.\n", __func__);
		return -ENOMEM;
	}

	/* Issue the request, attempting to read 'size' bytes */
	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
				request, REQTYPE_INTERFACE_TO_HOST, 0x0000,
				port_priv->bInterfaceNumber, buf, size,
				USB_CTRL_GET_TIMEOUT);

	/* Convert data into an array of integers */
	for (i = 0; i < length; i++)
		data[i] = le32_to_cpu(buf[i]);

	kfree(buf);

	if (result != size) {
		dev_dbg(&port->dev, "%s - Unable to send config request, request=0x%x size=%d result=%d\n",
			__func__, request, size, result);
		if (result > 0)
			result = -EPROTO;

		return result;
	}

	return 0;
}

/*
 * cp210x_set_config
 * Writes to the CP210x configuration registers
 * Values less than 16 bits wide are sent directly
 * 'size' is specified in bytes.
 */
static int cp210x_set_config(struct usb_serial_port *port, u8 request,
		unsigned int *data, int size)
{
	struct usb_serial *serial = port->serial;
	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
	__le32 *buf;
	int result, i, length;

	/* Number of integers required to contain the array */
	length = (((size - 1) | 3) + 1)/4;

	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
	if (!buf) {
		dev_err(&port->dev, "%s - out of memory.\n",
				__func__);
		return -ENOMEM;
	}

	/* Array of integers into bytes */
	for (i = 0; i < length; i++)
		buf[i] = cpu_to_le32(data[i]);

	if (size > 2) {
		result = usb_control_msg(serial->dev,
				usb_sndctrlpipe(serial->dev, 0),
				request, REQTYPE_HOST_TO_INTERFACE, 0x0000,
				port_priv->bInterfaceNumber, buf, size,
				USB_CTRL_SET_TIMEOUT);
	} else {
		result = usb_control_msg(serial->dev,
				usb_sndctrlpipe(serial->dev, 0),
				request, REQTYPE_HOST_TO_INTERFACE, data[0],
				port_priv->bInterfaceNumber, NULL, 0,
				USB_CTRL_SET_TIMEOUT);
	}

	kfree(buf);

	if ((size > 2 && result != size) || result < 0) {
		dev_dbg(&port->dev, "%s - Unable to send request, request=0x%x size=%d result=%d\n",
			__func__, request, size, result);
		if (result > 0)
			result = -EPROTO;

		return result;
	}

	return 0;
}

/*
 * cp210x_set_config_single
 * Convenience function for calling cp210x_set_config on single data values
 * without requiring an integer pointer
 */
static inline int cp210x_set_config_single(struct usb_serial_port *port,
		u8 request, unsigned int data)
{
	return cp210x_set_config(port, request, &data, 2);
}

/*
 * cp210x_quantise_baudrate
 * Quantises the baud rate as per AN205 Table 1
 */
static unsigned int cp210x_quantise_baudrate(unsigned int baud) {
	if (baud <= 300)
		baud = 300;
	else if (baud <= 600)      baud = 600;
	else if (baud <= 1200)     baud = 1200;
	else if (baud <= 1800)     baud = 1800;
	else if (baud <= 2400)     baud = 2400;
	else if (baud <= 4000)     baud = 4000;
	else if (baud <= 4803)     baud = 4800;
	else if (baud <= 7207)     baud = 7200;
	else if (baud <= 9612)     baud = 9600;
	else if (baud <= 14428)    baud = 14400;
	else if (baud <= 16062)    baud = 16000;
	else if (baud <= 19250)    baud = 19200;
	else if (baud <= 28912)    baud = 28800;
	else if (baud <= 38601)    baud = 38400;
	else if (baud <= 51558)    baud = 51200;
	else if (baud <= 56280)    baud = 56000;
	else if (baud <= 58053)    baud = 57600;
	else if (baud <= 64111)    baud = 64000;
	else if (baud <= 77608)    baud = 76800;
	else if (baud <= 117028)   baud = 115200;
	else if (baud <= 129347)   baud = 128000;
	else if (baud <= 156868)   baud = 153600;
	else if (baud <= 237832)   baud = 230400;
	else if (baud <= 254234)   baud = 250000;
	else if (baud <= 273066)   baud = 256000;
	else if (baud <= 491520)   baud = 460800;
	else if (baud <= 567138)   baud = 500000;
	else if (baud <= 670254)   baud = 576000;
	else if (baud < 1000000)
		baud = 921600;
	else if (baud > 2000000)
		baud = 2000000;
	return baud;
}

static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	int result;

	result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
								UART_ENABLE);
	if (result) {
		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
		return result;
	}

	/* Configure the termios structure */
	cp210x_get_termios(tty, port);

	/* The baud rate must be initialised on cp2104 */
	if (tty)
		cp210x_change_speed(tty, port, NULL);

	return usb_serial_generic_open(tty, port);
}

static void cp210x_close(struct usb_serial_port *port)
{
	usb_serial_generic_close(port);

	mutex_lock(&port->serial->disc_mutex);
	if (!port->serial->disconnected)
		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
	mutex_unlock(&port->serial->disc_mutex);
}

/*
 * cp210x_get_termios
 * Reads the baud rate, data bits, parity, stop bits and flow control mode
 * from the device, corrects any unsupported values, and configures the
 * termios structure to reflect the state of the device
 */
static void cp210x_get_termios(struct tty_struct *tty,
	struct usb_serial_port *port)
{
	unsigned int baud;

	if (tty) {
		cp210x_get_termios_port(tty->driver_data,
			&tty->termios.c_cflag, &baud);
		tty_encode_baud_rate(tty, baud, baud);
	}

	else {
		unsigned int cflag;
		cflag = 0;
		cp210x_get_termios_port(port, &cflag, &baud);
	}
}

/*
 * cp210x_get_termios_port
 * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
 */
static void cp210x_get_termios_port(struct usb_serial_port *port,
	unsigned int *cflagp, unsigned int *baudp)
{
	struct device *dev = &port->dev;
	unsigned int cflag, modem_ctl[4];
	unsigned int baud;
	unsigned int bits;

	cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);

	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
	*baudp = baud;

	cflag = *cflagp;

	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
	cflag &= ~CSIZE;
	switch (bits & BITS_DATA_MASK) {
	case BITS_DATA_5:
		dev_dbg(dev, "%s - data bits = 5\n", __func__);
		cflag |= CS5;
		break;
	case BITS_DATA_6:
		dev_dbg(dev, "%s - data bits = 6\n", __func__);
		cflag |= CS6;
		break;
	case BITS_DATA_7:
		dev_dbg(dev, "%s - data bits = 7\n", __func__);
		cflag |= CS7;
		break;
	case BITS_DATA_8:
		dev_dbg(dev, "%s - data bits = 8\n", __func__);
		cflag |= CS8;
		break;
	case BITS_DATA_9:
		dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __func__);
		cflag |= CS8;
		bits &= ~BITS_DATA_MASK;
		bits |= BITS_DATA_8;
		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
		break;
	default:
		dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
		cflag |= CS8;
		bits &= ~BITS_DATA_MASK;
		bits |= BITS_DATA_8;
		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
		break;
	}

	switch (bits & BITS_PARITY_MASK) {
	case BITS_PARITY_NONE:
		dev_dbg(dev, "%s - parity = NONE\n", __func__);
		cflag &= ~PARENB;
		break;
	case BITS_PARITY_ODD:
		dev_dbg(dev, "%s - parity = ODD\n", __func__);
		cflag |= (PARENB|PARODD);
		break;
	case BITS_PARITY_EVEN:
		dev_dbg(dev, "%s - parity = EVEN\n", __func__);
		cflag &= ~PARODD;
		cflag |= PARENB;
		break;
	case BITS_PARITY_MARK:
		dev_dbg(dev, "%s - parity = MARK\n", __func__);
		cflag |= (PARENB|PARODD|CMSPAR);
		break;
	case BITS_PARITY_SPACE:
		dev_dbg(dev, "%s - parity = SPACE\n", __func__);
		cflag &= ~PARODD;
		cflag |= (PARENB|CMSPAR);
		break;
	default:
		dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
		cflag &= ~PARENB;
		bits &= ~BITS_PARITY_MASK;
		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
		break;
	}

	cflag &= ~CSTOPB;
	switch (bits & BITS_STOP_MASK) {
	case BITS_STOP_1:
		dev_dbg(dev, "%s - stop bits = 1\n", __func__);
		break;
	case BITS_STOP_1_5:
		dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
		bits &= ~BITS_STOP_MASK;
		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
		break;
	case BITS_STOP_2:
		dev_dbg(dev, "%s - stop bits = 2\n", __func__);
		cflag |= CSTOPB;
		break;
	default:
		dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
		bits &= ~BITS_STOP_MASK;
		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
		break;
	}

	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
	if (modem_ctl[0] & 0x0008) {
		dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
		cflag |= CRTSCTS;
	} else {
		dev_dbg(dev, "%s - flow control = NONE\n", __func__);
		cflag &= ~CRTSCTS;
	}

	*cflagp = cflag;
}

/*
 * CP2101 supports the following baud rates:
 *
 *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
 *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
 *
 * CP2102 and CP2103 support the following additional rates:
 *
 *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
 *	576000
 *
 * The device will map a requested rate to a supported one, but the result
 * of requests for rates greater than 1053257 is undefined (see AN205).
 *
 * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
 * respectively, with an error less than 1%. The actual rates are determined
 * by
 *
 *	div = round(freq / (2 x prescale x request))
 *	actual = freq / (2 x prescale x div)
 *
 * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
 * or 1 otherwise.
 * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
 * otherwise.
 */
static void cp210x_change_speed(struct tty_struct *tty,
		struct usb_serial_port *port, struct ktermios *old_termios)
{
	u32 baud;

	baud = tty->termios.c_ospeed;

	/* This maps the requested rate to a rate valid on cp2102 or cp2103,
	 * or to an arbitrary rate in [1M,2M].
	 *
	 * NOTE: B0 is not implemented.
	 */
	baud = cp210x_quantise_baudrate(baud);

	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
	if (cp210x_set_config(port, CP210X_SET_BAUDRATE, &baud,
							sizeof(baud))) {
		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
		if (old_termios)
			baud = old_termios->c_ospeed;
		else
			baud = 9600;
	}

	tty_encode_baud_rate(tty, baud, baud);
}

static void cp210x_set_termios(struct tty_struct *tty,
		struct usb_serial_port *port, struct ktermios *old_termios)
{
	struct device *dev = &port->dev;
	unsigned int cflag, old_cflag;
	unsigned int bits;
	unsigned int modem_ctl[4];

	dev_dbg(dev, "%s - port %d\n", __func__, port->number);

	if (!tty)
		return;

	cflag = tty->termios.c_cflag;
	old_cflag = old_termios->c_cflag;

	if (tty->termios.c_ospeed != old_termios->c_ospeed)
		cp210x_change_speed(tty, port, old_termios);

	/* If the number of data bits is to be updated */
	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
		bits &= ~BITS_DATA_MASK;
		switch (cflag & CSIZE) {
		case CS5:
			bits |= BITS_DATA_5;
			dev_dbg(dev, "%s - data bits = 5\n", __func__);
			break;
		case CS6:
			bits |= BITS_DATA_6;
			dev_dbg(dev, "%s - data bits = 6\n", __func__);
			break;
		case CS7:
			bits |= BITS_DATA_7;
			dev_dbg(dev, "%s - data bits = 7\n", __func__);
			break;
		case CS8:
			bits |= BITS_DATA_8;
			dev_dbg(dev, "%s - data bits = 8\n", __func__);
			break;
		/*case CS9:
			bits |= BITS_DATA_9;
			dev_dbg(dev, "%s - data bits = 9\n", __func__);
			break;*/
		default:
			dev_dbg(dev, "cp210x driver does not support the number of bits requested, using 8 bit mode\n");
				bits |= BITS_DATA_8;
				break;
		}
		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
			dev_dbg(dev, "Number of data bits requested not supported by device\n");
	}

	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
		bits &= ~BITS_PARITY_MASK;
		if (cflag & PARENB) {
			if (cflag & CMSPAR) {
				if (cflag & PARODD) {
					bits |= BITS_PARITY_MARK;
					dev_dbg(dev, "%s - parity = MARK\n", __func__);
				} else {
					bits |= BITS_PARITY_SPACE;
					dev_dbg(dev, "%s - parity = SPACE\n", __func__);
				}
			} else {
				if (cflag & PARODD) {
					bits |= BITS_PARITY_ODD;
					dev_dbg(dev, "%s - parity = ODD\n", __func__);
				} else {
					bits |= BITS_PARITY_EVEN;
					dev_dbg(dev, "%s - parity = EVEN\n", __func__);
				}
			}
		}
		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
			dev_dbg(dev, "Parity mode not supported by device\n");
	}

	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
		bits &= ~BITS_STOP_MASK;
		if (cflag & CSTOPB) {
			bits |= BITS_STOP_2;
			dev_dbg(dev, "%s - stop bits = 2\n", __func__);
		} else {
			bits |= BITS_STOP_1;
			dev_dbg(dev, "%s - stop bits = 1\n", __func__);
		}
		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
			dev_dbg(dev, "Number of stop bits requested not supported by device\n");
	}

	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
		dev_dbg(dev, "%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
			__func__, modem_ctl[0], modem_ctl[1],
			modem_ctl[2], modem_ctl[3]);

		if (cflag & CRTSCTS) {
			modem_ctl[0] &= ~0x7B;
			modem_ctl[0] |= 0x09;
			modem_ctl[1] = 0x80;
			dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
		} else {
			modem_ctl[0] &= ~0x7B;
			modem_ctl[0] |= 0x01;
			modem_ctl[1] |= 0x40;
			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
		}

		dev_dbg(dev, "%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
			__func__, modem_ctl[0], modem_ctl[1],
			modem_ctl[2], modem_ctl[3]);
		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
	}

}

static int cp210x_tiocmset (struct tty_struct *tty,
		unsigned int set, unsigned int clear)
{
	struct usb_serial_port *port = tty->driver_data;
	return cp210x_tiocmset_port(port, set, clear);
}

static int cp210x_tiocmset_port(struct usb_serial_port *port,
		unsigned int set, unsigned int clear)
{
	unsigned int control = 0;

	if (set & TIOCM_RTS) {
		control |= CONTROL_RTS;
		control |= CONTROL_WRITE_RTS;
	}
	if (set & TIOCM_DTR) {
		control |= CONTROL_DTR;
		control |= CONTROL_WRITE_DTR;
	}
	if (clear & TIOCM_RTS) {
		control &= ~CONTROL_RTS;
		control |= CONTROL_WRITE_RTS;
	}
	if (clear & TIOCM_DTR) {
		control &= ~CONTROL_DTR;
		control |= CONTROL_WRITE_DTR;
	}

	dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);

	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
}

static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
{
	if (on)
		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
	else
		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
}

static int cp210x_tiocmget (struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	unsigned int control;
	int result;

	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);

	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
		|((control & CONTROL_RING)? TIOCM_RI  : 0)
		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);

	dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);

	return result;
}

static void cp210x_break_ctl (struct tty_struct *tty, int break_state)
{
	struct usb_serial_port *port = tty->driver_data;
	unsigned int state;

	if (break_state == 0)
		state = BREAK_OFF;
	else
		state = BREAK_ON;
	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
		state == BREAK_OFF ? "off" : "on");
	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
}

static int cp210x_startup(struct usb_serial *serial)
{
	struct cp210x_port_private *port_priv;
	int i;

	/* cp210x buffers behave strangely unless device is reset */
	usb_reset_device(serial->dev);

	for (i = 0; i < serial->num_ports; i++) {
		port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
		if (!port_priv)
			return -ENOMEM;

		port_priv->bInterfaceNumber =
		    serial->interface->cur_altsetting->desc.bInterfaceNumber;

		usb_set_serial_port_data(serial->port[i], port_priv);
	}

	return 0;
}

static void cp210x_release(struct usb_serial *serial)
{
	struct cp210x_port_private *port_priv;
	int i;

	for (i = 0; i < serial->num_ports; i++) {
		port_priv = usb_get_serial_port_data(serial->port[i]);
		kfree(port_priv);
		usb_set_serial_port_data(serial->port[i], NULL);
	}
}

module_usb_serial_driver(serial_drivers, id_table);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");