summaryrefslogtreecommitdiff
path: root/drivers/usb/serial/xr_serial.c
blob: 1d9a12628f8112d19455781dc23169e0d129a650 (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
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
// SPDX-License-Identifier: GPL-2.0+
/*
 * MaxLinear/Exar USB to Serial driver
 *
 * Copyright (c) 2020 Manivannan Sadhasivam <mani@kernel.org>
 * Copyright (c) 2021 Johan Hovold <johan@kernel.org>
 *
 * Based on the initial driver written by Patong Yang:
 *
 *   https://lore.kernel.org/r/20180404070634.nhspvmxcjwfgjkcv@advantechmxl-desktop
 *
 *   Copyright (c) 2018 Patong Yang <patong.mxl@gmail.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <linux/usb/serial.h>

struct xr_txrx_clk_mask {
	u16 tx;
	u16 rx0;
	u16 rx1;
};

#define XR_INT_OSC_HZ			48000000U
#define XR21V141X_MIN_SPEED		46U
#define XR21V141X_MAX_SPEED		XR_INT_OSC_HZ

/* XR21V141X register blocks */
#define XR21V141X_UART_REG_BLOCK	0
#define XR21V141X_UM_REG_BLOCK		4
#define XR21V141X_UART_CUSTOM_BLOCK	0x66

/* XR21V141X UART registers */
#define XR21V141X_CLOCK_DIVISOR_0	0x04
#define XR21V141X_CLOCK_DIVISOR_1	0x05
#define XR21V141X_CLOCK_DIVISOR_2	0x06
#define XR21V141X_TX_CLOCK_MASK_0	0x07
#define XR21V141X_TX_CLOCK_MASK_1	0x08
#define XR21V141X_RX_CLOCK_MASK_0	0x09
#define XR21V141X_RX_CLOCK_MASK_1	0x0a
#define XR21V141X_REG_FORMAT		0x0b

/* XR21V141X UART Manager registers */
#define XR21V141X_UM_FIFO_ENABLE_REG	0x10
#define XR21V141X_UM_ENABLE_TX_FIFO	0x01
#define XR21V141X_UM_ENABLE_RX_FIFO	0x02

#define XR21V141X_UM_RX_FIFO_RESET	0x18
#define XR21V141X_UM_TX_FIFO_RESET	0x1c

#define XR_UART_ENABLE_TX		0x1
#define XR_UART_ENABLE_RX		0x2

#define XR_GPIO_RI			BIT(0)
#define XR_GPIO_CD			BIT(1)
#define XR_GPIO_DSR			BIT(2)
#define XR_GPIO_DTR			BIT(3)
#define XR_GPIO_CTS			BIT(4)
#define XR_GPIO_RTS			BIT(5)
#define XR_GPIO_CLK			BIT(6)
#define XR_GPIO_XEN			BIT(7)
#define XR_GPIO_TXT			BIT(8)
#define XR_GPIO_RXT			BIT(9)

#define XR_UART_DATA_MASK		GENMASK(3, 0)
#define XR_UART_DATA_7			0x7
#define XR_UART_DATA_8			0x8

#define XR_UART_PARITY_MASK		GENMASK(6, 4)
#define XR_UART_PARITY_SHIFT		4
#define XR_UART_PARITY_NONE		(0x0 << XR_UART_PARITY_SHIFT)
#define XR_UART_PARITY_ODD		(0x1 << XR_UART_PARITY_SHIFT)
#define XR_UART_PARITY_EVEN		(0x2 <<	XR_UART_PARITY_SHIFT)
#define XR_UART_PARITY_MARK		(0x3 << XR_UART_PARITY_SHIFT)
#define XR_UART_PARITY_SPACE		(0x4 << XR_UART_PARITY_SHIFT)

#define XR_UART_STOP_MASK		BIT(7)
#define XR_UART_STOP_SHIFT		7
#define XR_UART_STOP_1			(0x0 << XR_UART_STOP_SHIFT)
#define XR_UART_STOP_2			(0x1 << XR_UART_STOP_SHIFT)

#define XR_UART_FLOW_MODE_NONE		0x0
#define XR_UART_FLOW_MODE_HW		0x1
#define XR_UART_FLOW_MODE_SW		0x2

#define XR_GPIO_MODE_SEL_MASK		GENMASK(2, 0)
#define XR_GPIO_MODE_SEL_RTS_CTS	0x1
#define XR_GPIO_MODE_SEL_DTR_DSR	0x2
#define XR_GPIO_MODE_SEL_RS485		0x3
#define XR_GPIO_MODE_SEL_RS485_ADDR	0x4
#define XR_GPIO_MODE_RS485_TX_H		0x8
#define XR_GPIO_MODE_TX_TOGGLE		0x100
#define XR_GPIO_MODE_RX_TOGGLE		0x200

#define XR_FIFO_RESET			0x1

#define XR_CUSTOM_DRIVER_ACTIVE		0x1

static int xr21v141x_uart_enable(struct usb_serial_port *port);
static int xr21v141x_uart_disable(struct usb_serial_port *port);
static int xr21v141x_fifo_reset(struct usb_serial_port *port);
static void xr21v141x_set_line_settings(struct tty_struct *tty,
					struct usb_serial_port *port,
					const struct ktermios *old_termios);

struct xr_type {
	int reg_width;
	u8 reg_recipient;
	u8 set_reg;
	u8 get_reg;

	u16 uart_enable;
	u16 flow_control;
	u16 xon_char;
	u16 xoff_char;
	u16 tx_break;
	u16 gpio_mode;
	u16 gpio_direction;
	u16 gpio_set;
	u16 gpio_clear;
	u16 gpio_status;
	u16 tx_fifo_reset;
	u16 rx_fifo_reset;
	u16 custom_driver;

	bool have_5_6_bit_mode;
	bool have_xmit_toggle;

	int (*enable)(struct usb_serial_port *port);
	int (*disable)(struct usb_serial_port *port);
	int (*fifo_reset)(struct usb_serial_port *port);
	void (*set_line_settings)(struct tty_struct *tty,
				  struct usb_serial_port *port,
				  const struct ktermios *old_termios);
};

enum xr_type_id {
	XR21V141X,
	XR21B142X,
	XR21B1411,
	XR2280X,
	XR_TYPE_COUNT,
};

static const struct xr_type xr_types[] = {
	[XR21V141X] = {
		.reg_width	= 8,
		.reg_recipient	= USB_RECIP_DEVICE,
		.set_reg	= 0x00,
		.get_reg	= 0x01,

		.uart_enable	= 0x03,
		.flow_control	= 0x0c,
		.xon_char	= 0x10,
		.xoff_char	= 0x11,
		.tx_break	= 0x14,
		.gpio_mode	= 0x1a,
		.gpio_direction	= 0x1b,
		.gpio_set	= 0x1d,
		.gpio_clear	= 0x1e,
		.gpio_status	= 0x1f,

		.enable			= xr21v141x_uart_enable,
		.disable		= xr21v141x_uart_disable,
		.fifo_reset		= xr21v141x_fifo_reset,
		.set_line_settings	= xr21v141x_set_line_settings,
	},
	[XR21B142X] = {
		.reg_width	= 16,
		.reg_recipient	= USB_RECIP_INTERFACE,
		.set_reg	= 0x00,
		.get_reg	= 0x00,

		.uart_enable	= 0x00,
		.flow_control	= 0x06,
		.xon_char	= 0x07,
		.xoff_char	= 0x08,
		.tx_break	= 0x0a,
		.gpio_mode	= 0x0c,
		.gpio_direction	= 0x0d,
		.gpio_set	= 0x0e,
		.gpio_clear	= 0x0f,
		.gpio_status	= 0x10,
		.tx_fifo_reset	= 0x40,
		.rx_fifo_reset	= 0x43,
		.custom_driver	= 0x60,

		.have_5_6_bit_mode	= true,
		.have_xmit_toggle	= true,
	},
	[XR21B1411] = {
		.reg_width	= 12,
		.reg_recipient	= USB_RECIP_DEVICE,
		.set_reg	= 0x00,
		.get_reg	= 0x01,

		.uart_enable	= 0xc00,
		.flow_control	= 0xc06,
		.xon_char	= 0xc07,
		.xoff_char	= 0xc08,
		.tx_break	= 0xc0a,
		.gpio_mode	= 0xc0c,
		.gpio_direction	= 0xc0d,
		.gpio_set	= 0xc0e,
		.gpio_clear	= 0xc0f,
		.gpio_status	= 0xc10,
		.tx_fifo_reset	= 0xc80,
		.rx_fifo_reset	= 0xcc0,
		.custom_driver	= 0x20d,
	},
	[XR2280X] = {
		.reg_width	= 16,
		.reg_recipient	= USB_RECIP_DEVICE,
		.set_reg	= 0x05,
		.get_reg	= 0x05,

		.uart_enable	= 0x40,
		.flow_control	= 0x46,
		.xon_char	= 0x47,
		.xoff_char	= 0x48,
		.tx_break	= 0x4a,
		.gpio_mode	= 0x4c,
		.gpio_direction	= 0x4d,
		.gpio_set	= 0x4e,
		.gpio_clear	= 0x4f,
		.gpio_status	= 0x50,
		.tx_fifo_reset	= 0x60,
		.rx_fifo_reset	= 0x63,
		.custom_driver	= 0x81,
	},
};

struct xr_data {
	const struct xr_type *type;
	u8 channel;			/* zero-based index or interface number */
	struct serial_rs485 rs485;
};

static int xr_set_reg(struct usb_serial_port *port, u8 channel, u16 reg, u16 val)
{
	struct xr_data *data = usb_get_serial_port_data(port);
	const struct xr_type *type = data->type;
	struct usb_serial *serial = port->serial;
	int ret;

	ret = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
			type->set_reg,
			USB_DIR_OUT | USB_TYPE_VENDOR | type->reg_recipient,
			val, (channel << 8) | reg, NULL, 0,
			USB_CTRL_SET_TIMEOUT);
	if (ret < 0) {
		dev_err(&port->dev, "Failed to set reg 0x%02x: %d\n", reg, ret);
		return ret;
	}

	return 0;
}

static int xr_get_reg(struct usb_serial_port *port, u8 channel, u16 reg, u16 *val)
{
	struct xr_data *data = usb_get_serial_port_data(port);
	const struct xr_type *type = data->type;
	struct usb_serial *serial = port->serial;
	u8 *dmabuf;
	int ret, len;

	if (type->reg_width == 8)
		len = 1;
	else
		len = 2;

	dmabuf = kmalloc(len, GFP_KERNEL);
	if (!dmabuf)
		return -ENOMEM;

	ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
			type->get_reg,
			USB_DIR_IN | USB_TYPE_VENDOR | type->reg_recipient,
			0, (channel << 8) | reg, dmabuf, len,
			USB_CTRL_GET_TIMEOUT);
	if (ret == len) {
		if (len == 2)
			*val = le16_to_cpup((__le16 *)dmabuf);
		else
			*val = *dmabuf;
		ret = 0;
	} else {
		dev_err(&port->dev, "Failed to get reg 0x%02x: %d\n", reg, ret);
		if (ret >= 0)
			ret = -EIO;
	}

	kfree(dmabuf);

	return ret;
}

static int xr_set_reg_uart(struct usb_serial_port *port, u16 reg, u16 val)
{
	struct xr_data *data = usb_get_serial_port_data(port);

	return xr_set_reg(port, data->channel, reg, val);
}

static int xr_get_reg_uart(struct usb_serial_port *port, u16 reg, u16 *val)
{
	struct xr_data *data = usb_get_serial_port_data(port);

	return xr_get_reg(port, data->channel, reg, val);
}

static int xr_set_reg_um(struct usb_serial_port *port, u8 reg_base, u8 val)
{
	struct xr_data *data = usb_get_serial_port_data(port);
	u8 reg;

	reg = reg_base + data->channel;

	return xr_set_reg(port, XR21V141X_UM_REG_BLOCK, reg, val);
}

static int __xr_uart_enable(struct usb_serial_port *port)
{
	struct xr_data *data = usb_get_serial_port_data(port);

	return xr_set_reg_uart(port, data->type->uart_enable,
			XR_UART_ENABLE_TX | XR_UART_ENABLE_RX);
}

static int __xr_uart_disable(struct usb_serial_port *port)
{
	struct xr_data *data = usb_get_serial_port_data(port);

	return xr_set_reg_uart(port, data->type->uart_enable, 0);
}

/*
 * According to datasheet, below is the recommended sequence for enabling UART
 * module in XR21V141X:
 *
 * Enable Tx FIFO
 * Enable Tx and Rx
 * Enable Rx FIFO
 */
static int xr21v141x_uart_enable(struct usb_serial_port *port)
{
	int ret;

	ret = xr_set_reg_um(port, XR21V141X_UM_FIFO_ENABLE_REG,
			    XR21V141X_UM_ENABLE_TX_FIFO);
	if (ret)
		return ret;

	ret = __xr_uart_enable(port);
	if (ret)
		return ret;

	ret = xr_set_reg_um(port, XR21V141X_UM_FIFO_ENABLE_REG,
			    XR21V141X_UM_ENABLE_TX_FIFO | XR21V141X_UM_ENABLE_RX_FIFO);
	if (ret)
		__xr_uart_disable(port);

	return ret;
}

static int xr21v141x_uart_disable(struct usb_serial_port *port)
{
	int ret;

	ret = __xr_uart_disable(port);
	if (ret)
		return ret;

	ret = xr_set_reg_um(port, XR21V141X_UM_FIFO_ENABLE_REG, 0);

	return ret;
}

static int xr_uart_enable(struct usb_serial_port *port)
{
	struct xr_data *data = usb_get_serial_port_data(port);

	if (data->type->enable)
		return data->type->enable(port);

	return __xr_uart_enable(port);
}

static int xr_uart_disable(struct usb_serial_port *port)
{
	struct xr_data *data = usb_get_serial_port_data(port);

	if (data->type->disable)
		return data->type->disable(port);

	return __xr_uart_disable(port);
}

static int xr21v141x_fifo_reset(struct usb_serial_port *port)
{
	int ret;

	ret = xr_set_reg_um(port, XR21V141X_UM_TX_FIFO_RESET, XR_FIFO_RESET);
	if (ret)
		return ret;

	ret = xr_set_reg_um(port, XR21V141X_UM_RX_FIFO_RESET, XR_FIFO_RESET);
	if (ret)
		return ret;

	return 0;
}

static int xr_fifo_reset(struct usb_serial_port *port)
{
	struct xr_data *data = usb_get_serial_port_data(port);
	int ret;

	if (data->type->fifo_reset)
		return data->type->fifo_reset(port);

	ret = xr_set_reg_uart(port, data->type->tx_fifo_reset, XR_FIFO_RESET);
	if (ret)
		return ret;

	ret = xr_set_reg_uart(port, data->type->rx_fifo_reset, XR_FIFO_RESET);
	if (ret)
		return ret;

	return 0;
}

static int xr_tiocmget(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct xr_data *data = usb_get_serial_port_data(port);
	u16 status;
	int ret;

	ret = xr_get_reg_uart(port, data->type->gpio_status, &status);
	if (ret)
		return ret;

	/*
	 * Modem control pins are active low, so reading '0' means it is active
	 * and '1' means not active.
	 */
	ret = ((status & XR_GPIO_DTR) ? 0 : TIOCM_DTR) |
	      ((status & XR_GPIO_RTS) ? 0 : TIOCM_RTS) |
	      ((status & XR_GPIO_CTS) ? 0 : TIOCM_CTS) |
	      ((status & XR_GPIO_DSR) ? 0 : TIOCM_DSR) |
	      ((status & XR_GPIO_RI) ? 0 : TIOCM_RI) |
	      ((status & XR_GPIO_CD) ? 0 : TIOCM_CD);

	return ret;
}

static int xr_tiocmset_port(struct usb_serial_port *port,
			    unsigned int set, unsigned int clear)
{
	struct xr_data *data = usb_get_serial_port_data(port);
	const struct xr_type *type = data->type;
	u16 gpio_set = 0;
	u16 gpio_clr = 0;
	int ret = 0;

	/* Modem control pins are active low, so set & clr are swapped */
	if (set & TIOCM_RTS)
		gpio_clr |= XR_GPIO_RTS;
	if (set & TIOCM_DTR)
		gpio_clr |= XR_GPIO_DTR;
	if (clear & TIOCM_RTS)
		gpio_set |= XR_GPIO_RTS;
	if (clear & TIOCM_DTR)
		gpio_set |= XR_GPIO_DTR;

	/* Writing '0' to gpio_{set/clr} bits has no effect, so no need to do */
	if (gpio_clr)
		ret = xr_set_reg_uart(port, type->gpio_clear, gpio_clr);

	if (gpio_set)
		ret = xr_set_reg_uart(port, type->gpio_set, gpio_set);

	return ret;
}

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

	return xr_tiocmset_port(port, set, clear);
}

static void xr_dtr_rts(struct usb_serial_port *port, int on)
{
	if (on)
		xr_tiocmset_port(port, TIOCM_DTR | TIOCM_RTS, 0);
	else
		xr_tiocmset_port(port, 0, TIOCM_DTR | TIOCM_RTS);
}

static int xr_break_ctl(struct tty_struct *tty, int break_state)
{
	struct usb_serial_port *port = tty->driver_data;
	struct xr_data *data = usb_get_serial_port_data(port);
	const struct xr_type *type = data->type;
	u16 state;

	if (break_state == 0)
		state = 0;
	else
		state = GENMASK(type->reg_width - 1, 0);

	dev_dbg(&port->dev, "Turning break %s\n", state == 0 ? "off" : "on");

	return xr_set_reg_uart(port, type->tx_break, state);
}

/* Tx and Rx clock mask values obtained from section 3.3.4 of datasheet */
static const struct xr_txrx_clk_mask xr21v141x_txrx_clk_masks[] = {
	{ 0x000, 0x000, 0x000 },
	{ 0x000, 0x000, 0x000 },
	{ 0x100, 0x000, 0x100 },
	{ 0x020, 0x400, 0x020 },
	{ 0x010, 0x100, 0x010 },
	{ 0x208, 0x040, 0x208 },
	{ 0x104, 0x820, 0x108 },
	{ 0x844, 0x210, 0x884 },
	{ 0x444, 0x110, 0x444 },
	{ 0x122, 0x888, 0x224 },
	{ 0x912, 0x448, 0x924 },
	{ 0x492, 0x248, 0x492 },
	{ 0x252, 0x928, 0x292 },
	{ 0x94a, 0x4a4, 0xa52 },
	{ 0x52a, 0xaa4, 0x54a },
	{ 0xaaa, 0x954, 0x4aa },
	{ 0xaaa, 0x554, 0xaaa },
	{ 0x555, 0xad4, 0x5aa },
	{ 0xb55, 0xab4, 0x55a },
	{ 0x6b5, 0x5ac, 0xb56 },
	{ 0x5b5, 0xd6c, 0x6d6 },
	{ 0xb6d, 0xb6a, 0xdb6 },
	{ 0x76d, 0x6da, 0xbb6 },
	{ 0xedd, 0xdda, 0x76e },
	{ 0xddd, 0xbba, 0xeee },
	{ 0x7bb, 0xf7a, 0xdde },
	{ 0xf7b, 0xef6, 0x7de },
	{ 0xdf7, 0xbf6, 0xf7e },
	{ 0x7f7, 0xfee, 0xefe },
	{ 0xfdf, 0xfbe, 0x7fe },
	{ 0xf7f, 0xefe, 0xffe },
	{ 0xfff, 0xffe, 0xffd },
};

static int xr21v141x_set_baudrate(struct tty_struct *tty, struct usb_serial_port *port)
{
	u32 divisor, baud, idx;
	u16 tx_mask, rx_mask;
	int ret;

	baud = tty->termios.c_ospeed;
	if (!baud)
		return 0;

	baud = clamp(baud, XR21V141X_MIN_SPEED, XR21V141X_MAX_SPEED);
	divisor = XR_INT_OSC_HZ / baud;
	idx = ((32 * XR_INT_OSC_HZ) / baud) & 0x1f;
	tx_mask = xr21v141x_txrx_clk_masks[idx].tx;

	if (divisor & 0x01)
		rx_mask = xr21v141x_txrx_clk_masks[idx].rx1;
	else
		rx_mask = xr21v141x_txrx_clk_masks[idx].rx0;

	dev_dbg(&port->dev, "Setting baud rate: %u\n", baud);
	/*
	 * XR21V141X uses fractional baud rate generator with 48MHz internal
	 * oscillator and 19-bit programmable divisor. So theoretically it can
	 * generate most commonly used baud rates with high accuracy.
	 */
	ret = xr_set_reg_uart(port, XR21V141X_CLOCK_DIVISOR_0,
			      divisor & 0xff);
	if (ret)
		return ret;

	ret = xr_set_reg_uart(port, XR21V141X_CLOCK_DIVISOR_1,
			      (divisor >>  8) & 0xff);
	if (ret)
		return ret;

	ret = xr_set_reg_uart(port, XR21V141X_CLOCK_DIVISOR_2,
			      (divisor >> 16) & 0xff);
	if (ret)
		return ret;

	ret = xr_set_reg_uart(port, XR21V141X_TX_CLOCK_MASK_0,
			      tx_mask & 0xff);
	if (ret)
		return ret;

	ret = xr_set_reg_uart(port, XR21V141X_TX_CLOCK_MASK_1,
			      (tx_mask >>  8) & 0xff);
	if (ret)
		return ret;

	ret = xr_set_reg_uart(port, XR21V141X_RX_CLOCK_MASK_0,
			      rx_mask & 0xff);
	if (ret)
		return ret;

	ret = xr_set_reg_uart(port, XR21V141X_RX_CLOCK_MASK_1,
			      (rx_mask >>  8) & 0xff);
	if (ret)
		return ret;

	tty_encode_baud_rate(tty, baud, baud);

	return 0;
}

static void xr_set_flow_mode(struct tty_struct *tty,
		             struct usb_serial_port *port,
		             const struct ktermios *old_termios)
{
	struct xr_data *data = usb_get_serial_port_data(port);
	const struct xr_type *type = data->type;
	u16 flow, gpio_mode;
	bool rs485_enabled;
	int ret;

	ret = xr_get_reg_uart(port, type->gpio_mode, &gpio_mode);
	if (ret)
		return;

	/*
	 * According to the datasheets, the UART needs to be disabled while
	 * writing to the FLOW_CONTROL register (XR21V141X), or any register
	 * but GPIO_SET, GPIO_CLEAR, TX_BREAK and ERROR_STATUS (XR21B142X).
	 */
	xr_uart_disable(port);

	/* Set GPIO mode for controlling the pins manually by default. */
	gpio_mode &= ~XR_GPIO_MODE_SEL_MASK;

	rs485_enabled = !!(data->rs485.flags & SER_RS485_ENABLED);
	if (rs485_enabled) {
		dev_dbg(&port->dev, "Enabling RS-485\n");
		gpio_mode |= XR_GPIO_MODE_SEL_RS485;
		if (data->rs485.flags & SER_RS485_RTS_ON_SEND)
			gpio_mode &= ~XR_GPIO_MODE_RS485_TX_H;
		else
			gpio_mode |= XR_GPIO_MODE_RS485_TX_H;
	}

	if (C_CRTSCTS(tty) && C_BAUD(tty) != B0 && !rs485_enabled) {
		dev_dbg(&port->dev, "Enabling hardware flow ctrl\n");
		gpio_mode |= XR_GPIO_MODE_SEL_RTS_CTS;
		flow = XR_UART_FLOW_MODE_HW;
	} else if (I_IXON(tty)) {
		u8 start_char = START_CHAR(tty);
		u8 stop_char = STOP_CHAR(tty);

		dev_dbg(&port->dev, "Enabling sw flow ctrl\n");
		flow = XR_UART_FLOW_MODE_SW;

		xr_set_reg_uart(port, type->xon_char, start_char);
		xr_set_reg_uart(port, type->xoff_char, stop_char);
	} else {
		dev_dbg(&port->dev, "Disabling flow ctrl\n");
		flow = XR_UART_FLOW_MODE_NONE;
	}

	xr_set_reg_uart(port, type->flow_control, flow);
	xr_set_reg_uart(port, type->gpio_mode, gpio_mode);

	xr_uart_enable(port);

	if (C_BAUD(tty) == B0)
		xr_dtr_rts(port, 0);
	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
		xr_dtr_rts(port, 1);
}

static void xr21v141x_set_line_settings(struct tty_struct *tty,
				        struct usb_serial_port *port,
				        const struct ktermios *old_termios)
{
	struct ktermios *termios = &tty->termios;
	u8 bits = 0;
	int ret;

	if (!old_termios || (tty->termios.c_ospeed != old_termios->c_ospeed))
		xr21v141x_set_baudrate(tty, port);

	switch (C_CSIZE(tty)) {
	case CS5:
	case CS6:
		/* CS5 and CS6 are not supported, so just restore old setting */
		termios->c_cflag &= ~CSIZE;
		if (old_termios)
			termios->c_cflag |= old_termios->c_cflag & CSIZE;
		else
			termios->c_cflag |= CS8;

		if (C_CSIZE(tty) == CS7)
			bits |= XR_UART_DATA_7;
		else
			bits |= XR_UART_DATA_8;
		break;
	case CS7:
		bits |= XR_UART_DATA_7;
		break;
	case CS8:
	default:
		bits |= XR_UART_DATA_8;
		break;
	}

	if (C_PARENB(tty)) {
		if (C_CMSPAR(tty)) {
			if (C_PARODD(tty))
				bits |= XR_UART_PARITY_MARK;
			else
				bits |= XR_UART_PARITY_SPACE;
		} else {
			if (C_PARODD(tty))
				bits |= XR_UART_PARITY_ODD;
			else
				bits |= XR_UART_PARITY_EVEN;
		}
	}

	if (C_CSTOPB(tty))
		bits |= XR_UART_STOP_2;
	else
		bits |= XR_UART_STOP_1;

	ret = xr_set_reg_uart(port, XR21V141X_REG_FORMAT, bits);
	if (ret)
		return;
}

static void xr_cdc_set_line_coding(struct tty_struct *tty,
				   struct usb_serial_port *port,
				   const struct ktermios *old_termios)
{
	struct xr_data *data = usb_get_serial_port_data(port);
	struct usb_host_interface *alt = port->serial->interface->cur_altsetting;
	struct usb_device *udev = port->serial->dev;
	struct usb_cdc_line_coding *lc;
	int ret;

	lc = kzalloc(sizeof(*lc), GFP_KERNEL);
	if (!lc)
		return;

	if (tty->termios.c_ospeed)
		lc->dwDTERate = cpu_to_le32(tty->termios.c_ospeed);
	else
		lc->dwDTERate = cpu_to_le32(9600);

	if (C_CSTOPB(tty))
		lc->bCharFormat = USB_CDC_2_STOP_BITS;
	else
		lc->bCharFormat = USB_CDC_1_STOP_BITS;

	if (C_PARENB(tty)) {
		if (C_CMSPAR(tty)) {
			if (C_PARODD(tty))
				lc->bParityType = USB_CDC_MARK_PARITY;
			else
				lc->bParityType = USB_CDC_SPACE_PARITY;
		} else {
			if (C_PARODD(tty))
				lc->bParityType = USB_CDC_ODD_PARITY;
			else
				lc->bParityType = USB_CDC_EVEN_PARITY;
		}
	} else {
		lc->bParityType = USB_CDC_NO_PARITY;
	}

	if (!data->type->have_5_6_bit_mode &&
			(C_CSIZE(tty) == CS5 || C_CSIZE(tty) == CS6)) {
		tty->termios.c_cflag &= ~CSIZE;
		if (old_termios)
			tty->termios.c_cflag |= old_termios->c_cflag & CSIZE;
		else
			tty->termios.c_cflag |= CS8;
	}

	switch (C_CSIZE(tty)) {
	case CS5:
		lc->bDataBits = 5;
		break;
	case CS6:
		lc->bDataBits = 6;
		break;
	case CS7:
		lc->bDataBits = 7;
		break;
	case CS8:
	default:
		lc->bDataBits = 8;
		break;
	}

	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			USB_CDC_REQ_SET_LINE_CODING,
			USB_TYPE_CLASS | USB_RECIP_INTERFACE,
			0, alt->desc.bInterfaceNumber,
			lc, sizeof(*lc), USB_CTRL_SET_TIMEOUT);
	if (ret < 0)
		dev_err(&port->dev, "Failed to set line coding: %d\n", ret);

	kfree(lc);
}

static void xr_sanitize_serial_rs485(struct serial_rs485 *rs485)
{
	if (!(rs485->flags & SER_RS485_ENABLED)) {
		memset(rs485, 0, sizeof(*rs485));
		return;
	}

	/* RTS always toggles after TX */
	if (rs485->flags & SER_RS485_RTS_ON_SEND)
		rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
	else
		rs485->flags |= SER_RS485_RTS_AFTER_SEND;

	/* Only the flags are implemented at the moment */
	rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
			SER_RS485_RTS_AFTER_SEND;
	rs485->delay_rts_before_send = 0;
	rs485->delay_rts_after_send = 0;
	memset(rs485->padding, 0, sizeof(rs485->padding));
}

static int xr_get_rs485_config(struct tty_struct *tty,
			       struct serial_rs485 __user *argp)
{
	struct usb_serial_port *port = tty->driver_data;
	struct xr_data *data = usb_get_serial_port_data(port);

	down_read(&tty->termios_rwsem);
	if (copy_to_user(argp, &data->rs485, sizeof(data->rs485))) {
		up_read(&tty->termios_rwsem);
		return -EFAULT;
	}
	up_read(&tty->termios_rwsem);

	return 0;
}

static int xr_set_rs485_config(struct tty_struct *tty,
			       struct serial_rs485 __user *argp)
{
	struct usb_serial_port *port = tty->driver_data;
	struct xr_data *data = usb_get_serial_port_data(port);
	struct serial_rs485 rs485;

	if (copy_from_user(&rs485, argp, sizeof(rs485)))
		return -EFAULT;
	xr_sanitize_serial_rs485(&rs485);

	down_write(&tty->termios_rwsem);
	data->rs485 = rs485;
	xr_set_flow_mode(tty, port, NULL);
	up_write(&tty->termios_rwsem);

	if (copy_to_user(argp, &rs485, sizeof(rs485)))
		return -EFAULT;

	return 0;
}

static int xr_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;

	switch (cmd) {
	case TIOCGRS485:
		return xr_get_rs485_config(tty, argp);
	case TIOCSRS485:
		return xr_set_rs485_config(tty, argp);
	}

	return -ENOIOCTLCMD;
}

static void xr_set_termios(struct tty_struct *tty,
			   struct usb_serial_port *port,
			   const struct ktermios *old_termios)
{
	struct xr_data *data = usb_get_serial_port_data(port);

	/*
	 * XR21V141X does not have a CUSTOM_DRIVER flag and always enters CDC
	 * mode upon receiving CDC requests.
	 */
	if (data->type->set_line_settings)
		data->type->set_line_settings(tty, port, old_termios);
	else
		xr_cdc_set_line_coding(tty, port, old_termios);

	xr_set_flow_mode(tty, port, old_termios);
}

static int xr_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	int ret;

	ret = xr_fifo_reset(port);
	if (ret)
		return ret;

	ret = xr_uart_enable(port);
	if (ret) {
		dev_err(&port->dev, "Failed to enable UART\n");
		return ret;
	}

	/* Setup termios */
	if (tty)
		xr_set_termios(tty, port, NULL);

	ret = usb_serial_generic_open(tty, port);
	if (ret) {
		xr_uart_disable(port);
		return ret;
	}

	return 0;
}

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

	xr_uart_disable(port);
}

static int xr_probe(struct usb_serial *serial, const struct usb_device_id *id)
{
	struct usb_interface *control = serial->interface;
	struct usb_host_interface *alt = control->cur_altsetting;
	struct usb_cdc_parsed_header hdrs;
	struct usb_cdc_union_desc *desc;
	struct usb_interface *data;
	int ret;

	ret = cdc_parse_cdc_header(&hdrs, control, alt->extra, alt->extralen);
	if (ret < 0)
		return -ENODEV;

	desc = hdrs.usb_cdc_union_desc;
	if (!desc)
		return -ENODEV;

	data = usb_ifnum_to_if(serial->dev, desc->bSlaveInterface0);
	if (!data)
		return -ENODEV;

	ret = usb_serial_claim_interface(serial, data);
	if (ret)
		return ret;

	usb_set_serial_data(serial, (void *)id->driver_info);

	return 0;
}

static int xr_gpio_init(struct usb_serial_port *port, const struct xr_type *type)
{
	u16 mask, mode;
	int ret;

	/*
	 * Configure all pins as GPIO except for Receive and Transmit Toggle.
	 */
	mode = 0;
	if (type->have_xmit_toggle)
		mode |= XR_GPIO_MODE_RX_TOGGLE | XR_GPIO_MODE_TX_TOGGLE;

	ret = xr_set_reg_uart(port, type->gpio_mode, mode);
	if (ret)
		return ret;

	/*
	 * Configure DTR and RTS as outputs and make sure they are deasserted
	 * (active low), and configure RI, CD, DSR and CTS as inputs.
	 */
	mask = XR_GPIO_DTR | XR_GPIO_RTS;
	ret = xr_set_reg_uart(port, type->gpio_direction, mask);
	if (ret)
		return ret;

	ret = xr_set_reg_uart(port, type->gpio_set, mask);
	if (ret)
		return ret;

	return 0;
}

static int xr_port_probe(struct usb_serial_port *port)
{
	struct usb_interface_descriptor *desc;
	const struct xr_type *type;
	struct xr_data *data;
	enum xr_type_id type_id;
	int ret;

	type_id = (int)(unsigned long)usb_get_serial_data(port->serial);
	type = &xr_types[type_id];

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->type = type;

	desc = &port->serial->interface->cur_altsetting->desc;
	if (type_id == XR21V141X)
		data->channel = desc->bInterfaceNumber / 2;
	else
		data->channel = desc->bInterfaceNumber;

	usb_set_serial_port_data(port, data);

	if (type->custom_driver) {
		ret = xr_set_reg_uart(port, type->custom_driver,
				XR_CUSTOM_DRIVER_ACTIVE);
		if (ret)
			goto err_free;
	}

	ret = xr_gpio_init(port, type);
	if (ret)
		goto err_free;

	return 0;

err_free:
	kfree(data);

	return ret;
}

static void xr_port_remove(struct usb_serial_port *port)
{
	struct xr_data *data = usb_get_serial_port_data(port);

	kfree(data);
}

#define XR_DEVICE(vid, pid, type)					\
	USB_DEVICE_INTERFACE_CLASS((vid), (pid), USB_CLASS_COMM),	\
	.driver_info = (type)

static const struct usb_device_id id_table[] = {
	{ XR_DEVICE(0x04e2, 0x1400, XR2280X) },
	{ XR_DEVICE(0x04e2, 0x1401, XR2280X) },
	{ XR_DEVICE(0x04e2, 0x1402, XR2280X) },
	{ XR_DEVICE(0x04e2, 0x1403, XR2280X) },
	{ XR_DEVICE(0x04e2, 0x1410, XR21V141X) },
	{ XR_DEVICE(0x04e2, 0x1411, XR21B1411) },
	{ XR_DEVICE(0x04e2, 0x1412, XR21V141X) },
	{ XR_DEVICE(0x04e2, 0x1414, XR21V141X) },
	{ XR_DEVICE(0x04e2, 0x1420, XR21B142X) },
	{ XR_DEVICE(0x04e2, 0x1422, XR21B142X) },
	{ XR_DEVICE(0x04e2, 0x1424, XR21B142X) },
	{ }
};
MODULE_DEVICE_TABLE(usb, id_table);

static struct usb_serial_driver xr_device = {
	.driver = {
		.owner = THIS_MODULE,
		.name =	"xr_serial",
	},
	.id_table		= id_table,
	.num_ports		= 1,
	.probe			= xr_probe,
	.port_probe		= xr_port_probe,
	.port_remove		= xr_port_remove,
	.open			= xr_open,
	.close			= xr_close,
	.break_ctl		= xr_break_ctl,
	.set_termios		= xr_set_termios,
	.tiocmget		= xr_tiocmget,
	.tiocmset		= xr_tiocmset,
	.ioctl			= xr_ioctl,
	.dtr_rts		= xr_dtr_rts
};

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

module_usb_serial_driver(serial_drivers, id_table);

MODULE_AUTHOR("Manivannan Sadhasivam <mani@kernel.org>");
MODULE_DESCRIPTION("MaxLinear/Exar USB to Serial driver");
MODULE_LICENSE("GPL");