aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/bfin_sport_uart.c
blob: ee101c0d358f70f23c480adf251781d42201be89 (plain) (blame)
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
/*
 * Blackfin On-Chip Sport Emulated UART Driver
 *
 * Copyright 2006-2009 Analog Devices Inc.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

/*
 * This driver and the hardware supported are in term of EE-191 of ADI.
 * http://www.analog.com/static/imported-files/application_notes/EE191.pdf 
 * This application note describe how to implement a UART on a Sharc DSP,
 * but this driver is implemented on Blackfin Processor.
 * Transmit Frame Sync is not used by this driver to transfer data out.
 */

/* #define DEBUG */

#define DRV_NAME "bfin-sport-uart"
#define DEVICE_NAME	"ttySS"
#define pr_fmt(fmt) DRV_NAME ": " fmt

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>

#include <asm/bfin_sport.h>
#include <asm/delay.h>
#include <asm/portmux.h>

#include "bfin_sport_uart.h"

struct sport_uart_port {
	struct uart_port	port;
	int			err_irq;
	unsigned short		csize;
	unsigned short		rxmask;
	unsigned short		txmask1;
	unsigned short		txmask2;
	unsigned char		stopb;
/*	unsigned char		parib; */
#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
	int cts_pin;
	int rts_pin;
#endif
};

static int sport_uart_tx_chars(struct sport_uart_port *up);
static void sport_stop_tx(struct uart_port *port);

static inline void tx_one_byte(struct sport_uart_port *up, unsigned int value)
{
	pr_debug("%s value:%x, mask1=0x%x, mask2=0x%x\n", __func__, value,
		up->txmask1, up->txmask2);

	/* Place Start and Stop bits */
	__asm__ __volatile__ (
		"%[val] <<= 1;"
		"%[val] = %[val] & %[mask1];"
		"%[val] = %[val] | %[mask2];"
		: [val]"+d"(value)
		: [mask1]"d"(up->txmask1), [mask2]"d"(up->txmask2)
		: "ASTAT"
	);
	pr_debug("%s value:%x\n", __func__, value);

	SPORT_PUT_TX(up, value);
}

static inline unsigned char rx_one_byte(struct sport_uart_port *up)
{
	unsigned int value;
	unsigned char extract;
	u32 tmp_mask1, tmp_mask2, tmp_shift, tmp;

	if ((up->csize + up->stopb) > 7)
		value = SPORT_GET_RX32(up);
	else
		value = SPORT_GET_RX(up);

	pr_debug("%s value:%x, cs=%d, mask=0x%x\n", __func__, value,
		up->csize, up->rxmask);

	/* Extract data */
	__asm__ __volatile__ (
		"%[extr] = 0;"
		"%[mask1] = %[rxmask];"
		"%[mask2] = 0x0200(Z);"
		"%[shift] = 0;"
		"LSETUP(.Lloop_s, .Lloop_e) LC0 = %[lc];"
		".Lloop_s:"
		"%[tmp] = extract(%[val], %[mask1].L)(Z);"
		"%[tmp] <<= %[shift];"
		"%[extr] = %[extr] | %[tmp];"
		"%[mask1] = %[mask1] - %[mask2];"
		".Lloop_e:"
		"%[shift] += 1;"
		: [extr]"=&d"(extract), [shift]"=&d"(tmp_shift), [tmp]"=&d"(tmp),
		  [mask1]"=&d"(tmp_mask1), [mask2]"=&d"(tmp_mask2)
		: [val]"d"(value), [rxmask]"d"(up->rxmask), [lc]"a"(up->csize)
		: "ASTAT", "LB0", "LC0", "LT0"
	);

	pr_debug("	extract:%x\n", extract);
	return extract;
}

static int sport_uart_setup(struct sport_uart_port *up, int size, int baud_rate)
{
	int tclkdiv, rclkdiv;
	unsigned int sclk = get_sclk();

	/* Set TCR1 and TCR2, TFSR is not enabled for uart */
	SPORT_PUT_TCR1(up, (LATFS | ITFS | TFSR | TLSBIT | ITCLK));
	SPORT_PUT_TCR2(up, size + 1);
	pr_debug("%s TCR1:%x, TCR2:%x\n", __func__, SPORT_GET_TCR1(up), SPORT_GET_TCR2(up));

	/* Set RCR1 and RCR2 */
	SPORT_PUT_RCR1(up, (RCKFE | LARFS | LRFS | RFSR | IRCLK));
	SPORT_PUT_RCR2(up, (size + 1) * 2 - 1);
	pr_debug("%s RCR1:%x, RCR2:%x\n", __func__, SPORT_GET_RCR1(up), SPORT_GET_RCR2(up));

	tclkdiv = sclk / (2 * baud_rate) - 1;
	/* The actual uart baud rate of devices vary between +/-2%. The sport
	 * RX sample rate should be faster than the double of the worst case,
	 * otherwise, wrong data are received. So, set sport RX clock to be
	 * 3% faster.
	 */
	rclkdiv = sclk / (2 * baud_rate * 2 * 97 / 100) - 1;
	SPORT_PUT_TCLKDIV(up, tclkdiv);
	SPORT_PUT_RCLKDIV(up, rclkdiv);
	SSYNC();
	pr_debug("%s sclk:%d, baud_rate:%d, tclkdiv:%d, rclkdiv:%d\n",
			__func__, sclk, baud_rate, tclkdiv, rclkdiv);

	return 0;
}

static irqreturn_t sport_uart_rx_irq(int irq, void *dev_id)
{
	struct sport_uart_port *up = dev_id;
	struct tty_struct *tty = up->port.state->port.tty;
	unsigned int ch;

	spin_lock(&up->port.lock);

	while (SPORT_GET_STAT(up) & RXNE) {
		ch = rx_one_byte(up);
		up->port.icount.rx++;

		if (!uart_handle_sysrq_char(&up->port, ch))
			tty_insert_flip_char(tty, ch, TTY_NORMAL);
	}
	tty_flip_buffer_push(tty);

	spin_unlock(&up->port.lock);

	return IRQ_HANDLED;
}

static irqreturn_t sport_uart_tx_irq(int irq, void *dev_id)
{
	struct sport_uart_port *up = dev_id;

	spin_lock(&up->port.lock);
	sport_uart_tx_chars(up);
	spin_unlock(&up->port.lock);

	return IRQ_HANDLED;
}

static irqreturn_t sport_uart_err_irq(int irq, void *dev_id)
{
	struct sport_uart_port *up = dev_id;
	struct tty_struct *tty = up->port.state->port.tty;
	unsigned int stat = SPORT_GET_STAT(up);

	spin_lock(&up->port.lock);

	/* Overflow in RX FIFO */
	if (stat & ROVF) {
		up->port.icount.overrun++;
		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
		SPORT_PUT_STAT(up, ROVF); /* Clear ROVF bit */
	}
	/* These should not happen */
	if (stat & (TOVF | TUVF | RUVF)) {
		pr_err("SPORT Error:%s %s %s\n",
		       (stat & TOVF) ? "TX overflow" : "",
		       (stat & TUVF) ? "TX underflow" : "",
		       (stat & RUVF) ? "RX underflow" : "");
		SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
		SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
	}
	SSYNC();

	spin_unlock(&up->port.lock);
	return IRQ_HANDLED;
}

#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
static unsigned int sport_get_mctrl(struct uart_port *port)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;
	if (up->cts_pin < 0)
		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;

	/* CTS PIN is negative assertive. */
	if (SPORT_UART_GET_CTS(up))
		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
	else
		return TIOCM_DSR | TIOCM_CAR;
}

static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;
	if (up->rts_pin < 0)
		return;

	/* RTS PIN is negative assertive. */
	if (mctrl & TIOCM_RTS)
		SPORT_UART_ENABLE_RTS(up);
	else
		SPORT_UART_DISABLE_RTS(up);
}

/*
 * Handle any change of modem status signal.
 */
static irqreturn_t sport_mctrl_cts_int(int irq, void *dev_id)
{
	struct sport_uart_port *up = (struct sport_uart_port *)dev_id;
	unsigned int status;

	status = sport_get_mctrl(&up->port);
	uart_handle_cts_change(&up->port, status & TIOCM_CTS);

	return IRQ_HANDLED;
}
#else
static unsigned int sport_get_mctrl(struct uart_port *port)
{
	pr_debug("%s enter\n", __func__);
	return TIOCM_CTS | TIOCM_CD | TIOCM_DSR;
}

static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
	pr_debug("%s enter\n", __func__);
}
#endif

/* Reqeust IRQ, Setup clock */
static int sport_startup(struct uart_port *port)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;
	int ret;

	pr_debug("%s enter\n", __func__);
	ret = request_irq(up->port.irq, sport_uart_rx_irq, 0,
		"SPORT_UART_RX", up);
	if (ret) {
		dev_err(port->dev, "unable to request SPORT RX interrupt\n");
		return ret;
	}

	ret = request_irq(up->port.irq+1, sport_uart_tx_irq, 0,
		"SPORT_UART_TX", up);
	if (ret) {
		dev_err(port->dev, "unable to request SPORT TX interrupt\n");
		goto fail1;
	}

	ret = request_irq(up->err_irq, sport_uart_err_irq, 0,
		"SPORT_UART_STATUS", up);
	if (ret) {
		dev_err(port->dev, "unable to request SPORT status interrupt\n");
		goto fail2;
	}

#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
	if (up->cts_pin >= 0) {
		if (request_irq(gpio_to_irq(up->cts_pin),
			sport_mctrl_cts_int,
			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
			0, "BFIN_SPORT_UART_CTS", up)) {
			up->cts_pin = -1;
			dev_info(port->dev, "Unable to attach BlackFin UART over SPORT CTS interrupt. So, disable it.\n");
		}
	}
	if (up->rts_pin >= 0)
		gpio_direction_output(up->rts_pin, 0);
#endif

	return 0;
 fail2:
	free_irq(up->port.irq+1, up);
 fail1:
	free_irq(up->port.irq, up);

	return ret;
}

/*
 * sport_uart_tx_chars
 *
 * ret 1 means need to enable sport.
 * ret 0 means do nothing.
 */
static int sport_uart_tx_chars(struct sport_uart_port *up)
{
	struct circ_buf *xmit = &up->port.state->xmit;

	if (SPORT_GET_STAT(up) & TXF)
		return 0;

	if (up->port.x_char) {
		tx_one_byte(up, up->port.x_char);
		up->port.icount.tx++;
		up->port.x_char = 0;
		return 1;
	}

	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
		/* The waiting loop to stop SPORT TX from TX interrupt is
		 * too long. This may block SPORT RX interrupts and cause
		 * RX FIFO overflow. So, do stop sport TX only after the last
		 * char in TX FIFO is moved into the shift register.
		 */
		if (SPORT_GET_STAT(up) & TXHRE)
			sport_stop_tx(&up->port);
		return 0;
	}

	while(!(SPORT_GET_STAT(up) & TXF) && !uart_circ_empty(xmit)) {
		tx_one_byte(up, xmit->buf[xmit->tail]);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
		up->port.icount.tx++;
	}

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(&up->port);

	return 1;
}

static unsigned int sport_tx_empty(struct uart_port *port)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;
	unsigned int stat;

	stat = SPORT_GET_STAT(up);
	pr_debug("%s stat:%04x\n", __func__, stat);
	if (stat & TXHRE) {
		return TIOCSER_TEMT;
	} else
		return 0;
}

static void sport_stop_tx(struct uart_port *port)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;

	pr_debug("%s enter\n", __func__);

	if (!(SPORT_GET_TCR1(up) & TSPEN))
		return;

	/* Although the hold register is empty, last byte is still in shift
	 * register and not sent out yet. So, put a dummy data into TX FIFO.
	 * Then, sport tx stops when last byte is shift out and the dummy
	 * data is moved into the shift register.
	 */
	SPORT_PUT_TX(up, 0xffff);
	while (!(SPORT_GET_STAT(up) & TXHRE))
		cpu_relax();

	SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
	SSYNC();

	return;
}

static void sport_start_tx(struct uart_port *port)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;

	pr_debug("%s enter\n", __func__);

	/* Write data into SPORT FIFO before enable SPROT to transmit */
	if (sport_uart_tx_chars(up)) {
		/* Enable transmit, then an interrupt will generated */
		SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
		SSYNC();
	}

	pr_debug("%s exit\n", __func__);
}

static void sport_stop_rx(struct uart_port *port)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;

	pr_debug("%s enter\n", __func__);
	/* Disable sport to stop rx */
	SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
	SSYNC();
}

static void sport_enable_ms(struct uart_port *port)
{
	pr_debug("%s enter\n", __func__);
}

static void sport_break_ctl(struct uart_port *port, int break_state)
{
	pr_debug("%s enter\n", __func__);
}

static void sport_shutdown(struct uart_port *port)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;

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

	/* Disable sport */
	SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
	SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
	SSYNC();

	free_irq(up->port.irq, up);
	free_irq(up->port.irq+1, up);
	free_irq(up->err_irq, up);
#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
	if (up->cts_pin >= 0)
		free_irq(gpio_to_irq(up->cts_pin), up);
#endif
}

static const char *sport_type(struct uart_port *port)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;

	pr_debug("%s enter\n", __func__);
	return up->port.type == PORT_BFIN_SPORT ? "BFIN-SPORT-UART" : NULL;
}

static void sport_release_port(struct uart_port *port)
{
	pr_debug("%s enter\n", __func__);
}

static int sport_request_port(struct uart_port *port)
{
	pr_debug("%s enter\n", __func__);
	return 0;
}

static void sport_config_port(struct uart_port *port, int flags)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;

	pr_debug("%s enter\n", __func__);
	up->port.type = PORT_BFIN_SPORT;
}

static int sport_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	pr_debug("%s enter\n", __func__);
	return 0;
}

static void sport_set_termios(struct uart_port *port,
		struct ktermios *termios, struct ktermios *old)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;
	unsigned long flags;
	int i;

	pr_debug("%s enter, c_cflag:%08x\n", __func__, termios->c_cflag);

	switch (termios->c_cflag & CSIZE) {
	case CS8:
		up->csize = 8;
		break;
	case CS7:
		up->csize = 7;
		break;
	case CS6:
		up->csize = 6;
		break;
	case CS5:
		up->csize = 5;
		break;
	default:
		pr_warning("requested word length not supported\n");
	}

	if (termios->c_cflag & CSTOPB) {
		up->stopb = 1;
	}
	if (termios->c_cflag & PARENB) {
		pr_warning("PAREN bits is not supported yet\n");
		/* up->parib = 1; */
	}

	spin_lock_irqsave(&up->port.lock, flags);

	port->read_status_mask = 0;

	/*
	 * Characters to ignore
	 */
	port->ignore_status_mask = 0;

	/* RX extract mask */
	up->rxmask = 0x01 | (((up->csize + up->stopb) * 2 - 1) << 0x8);
	/* TX masks, 8 bit data and 1 bit stop for example:
	 * mask1 = b#0111111110
	 * mask2 = b#1000000000
	 */
	for (i = 0, up->txmask1 = 0; i < up->csize; i++)
		up->txmask1 |= (1<<i);
	up->txmask2 = (1<<i);
	if (up->stopb) {
		++i;
		up->txmask2 |= (1<<i);
	}
	up->txmask1 <<= 1;
	up->txmask2 <<= 1;
	/* uart baud rate */
	port->uartclk = uart_get_baud_rate(port, termios, old, 0, get_sclk()/16);

	/* Disable UART */
	SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
	SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);

	sport_uart_setup(up, up->csize + up->stopb, port->uartclk);

	/* driver TX line high after config, one dummy data is
	 * necessary to stop sport after shift one byte
	 */
	SPORT_PUT_TX(up, 0xffff);
	SPORT_PUT_TX(up, 0xffff);
	SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
	SSYNC();
	while (!(SPORT_GET_STAT(up) & TXHRE))
		cpu_relax();
	SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
	SSYNC();

	/* Port speed changed, update the per-port timeout. */
	uart_update_timeout(port, termios->c_cflag, port->uartclk);

	/* Enable sport rx */
	SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) | RSPEN);
	SSYNC();

	spin_unlock_irqrestore(&up->port.lock, flags);
}

struct uart_ops sport_uart_ops = {
	.tx_empty	= sport_tx_empty,
	.set_mctrl	= sport_set_mctrl,
	.get_mctrl	= sport_get_mctrl,
	.stop_tx	= sport_stop_tx,
	.start_tx	= sport_start_tx,
	.stop_rx	= sport_stop_rx,
	.enable_ms	= sport_enable_ms,
	.break_ctl	= sport_break_ctl,
	.startup	= sport_startup,
	.shutdown	= sport_shutdown,
	.set_termios	= sport_set_termios,
	.type		= sport_type,
	.release_port	= sport_release_port,
	.request_port	= sport_request_port,
	.config_port	= sport_config_port,
	.verify_port	= sport_verify_port,
};

#define BFIN_SPORT_UART_MAX_PORTS 4

static struct sport_uart_port *bfin_sport_uart_ports[BFIN_SPORT_UART_MAX_PORTS];

#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
#define CLASS_BFIN_SPORT_CONSOLE	"bfin-sport-console"

static int __init
sport_uart_console_setup(struct console *co, char *options)
{
	struct sport_uart_port *up;
	int baud = 57600;
	int bits = 8;
	int parity = 'n';
# ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
	int flow = 'r';
# else
	int flow = 'n';
# endif

	/* Check whether an invalid uart number has been specified */
	if (co->index < 0 || co->index >= BFIN_SPORT_UART_MAX_PORTS)
		return -ENODEV;

	up = bfin_sport_uart_ports[co->index];
	if (!up)
		return -ENODEV;

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);

	return uart_set_options(&up->port, co, baud, parity, bits, flow);
}

static void sport_uart_console_putchar(struct uart_port *port, int ch)
{
	struct sport_uart_port *up = (struct sport_uart_port *)port;

	while (SPORT_GET_STAT(up) & TXF)
		barrier();

	tx_one_byte(up, ch);
}

/*
 * Interrupts are disabled on entering
 */
static void
sport_uart_console_write(struct console *co, const char *s, unsigned int count)
{
	struct sport_uart_port *up = bfin_sport_uart_ports[co->index];
	unsigned long flags;

	spin_lock_irqsave(&up->port.lock, flags);

	if (SPORT_GET_TCR1(up) & TSPEN)
		uart_console_write(&up->port, s, count, sport_uart_console_putchar);
	else {
		/* dummy data to start sport */
		while (SPORT_GET_STAT(up) & TXF)
			barrier();
		SPORT_PUT_TX(up, 0xffff);
		/* Enable transmit, then an interrupt will generated */
		SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
		SSYNC();

		uart_console_write(&up->port, s, count, sport_uart_console_putchar);

		/* Although the hold register is empty, last byte is still in shift
		 * register and not sent out yet. So, put a dummy data into TX FIFO.
		 * Then, sport tx stops when last byte is shift out and the dummy
		 * data is moved into the shift register.
		 */
		while (SPORT_GET_STAT(up) & TXF)
			barrier();
		SPORT_PUT_TX(up, 0xffff);
		while (!(SPORT_GET_STAT(up) & TXHRE))
			barrier();

		/* Stop sport tx transfer */
		SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
		SSYNC();
	}

	spin_unlock_irqrestore(&up->port.lock, flags);
}

static struct uart_driver sport_uart_reg;

static struct console sport_uart_console = {
	.name		= DEVICE_NAME,
	.write		= sport_uart_console_write,
	.device		= uart_console_device,
	.setup		= sport_uart_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &sport_uart_reg,
};

#define SPORT_UART_CONSOLE	(&sport_uart_console)
#else
#define SPORT_UART_CONSOLE	NULL
#endif /* CONFIG_SERIAL_BFIN_SPORT_CONSOLE */


static struct uart_driver sport_uart_reg = {
	.owner		= THIS_MODULE,
	.driver_name	= DRV_NAME,
	.dev_name	= DEVICE_NAME,
	.major		= 204,
	.minor		= 84,
	.nr		= BFIN_SPORT_UART_MAX_PORTS,
	.cons		= SPORT_UART_CONSOLE,
};

#ifdef CONFIG_PM
static int sport_uart_suspend(struct device *dev)
{
	struct sport_uart_port *sport = dev_get_drvdata(dev);

	dev_dbg(dev, "%s enter\n", __func__);
	if (sport)
		uart_suspend_port(&sport_uart_reg, &sport->port);

	return 0;
}

static int sport_uart_resume(struct device *dev)
{
	struct sport_uart_port *sport = dev_get_drvdata(dev);

	dev_dbg(dev, "%s enter\n", __func__);
	if (sport)
		uart_resume_port(&sport_uart_reg, &sport->port);

	return 0;
}

static struct dev_pm_ops bfin_sport_uart_dev_pm_ops = {
	.suspend	= sport_uart_suspend,
	.resume		= sport_uart_resume,
};
#endif

static int __devinit sport_uart_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct sport_uart_port *sport;
	int ret = 0;

	dev_dbg(&pdev->dev, "%s enter\n", __func__);

	if (pdev->id < 0 || pdev->id >= BFIN_SPORT_UART_MAX_PORTS) {
		dev_err(&pdev->dev, "Wrong sport uart platform device id.\n");
		return -ENOENT;
	}

	if (bfin_sport_uart_ports[pdev->id] == NULL) {
		bfin_sport_uart_ports[pdev->id] =
			kzalloc(sizeof(struct sport_uart_port), GFP_KERNEL);
		sport = bfin_sport_uart_ports[pdev->id];
		if (!sport) {
			dev_err(&pdev->dev,
				"Fail to malloc sport_uart_port\n");
			return -ENOMEM;
		}

		ret = peripheral_request_list(
			(unsigned short *)pdev->dev.platform_data, DRV_NAME);
		if (ret) {
			dev_err(&pdev->dev,
				"Fail to request SPORT peripherals\n");
			goto out_error_free_mem;
		}

		spin_lock_init(&sport->port.lock);
		sport->port.fifosize  = SPORT_TX_FIFO_SIZE,
		sport->port.ops       = &sport_uart_ops;
		sport->port.line      = pdev->id;
		sport->port.iotype    = UPIO_MEM;
		sport->port.flags     = UPF_BOOT_AUTOCONF;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		if (res == NULL) {
			dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
			ret = -ENOENT;
			goto out_error_free_peripherals;
		}

		sport->port.membase = ioremap(res->start, resource_size(res));
		if (!sport->port.membase) {
			dev_err(&pdev->dev, "Cannot map sport IO\n");
			ret = -ENXIO;
			goto out_error_free_peripherals;
		}
		sport->port.mapbase = res->start;

		sport->port.irq = platform_get_irq(pdev, 0);
		if ((int)sport->port.irq < 0) {
			dev_err(&pdev->dev, "No sport RX/TX IRQ specified\n");
			ret = -ENOENT;
			goto out_error_unmap;
		}

		sport->err_irq = platform_get_irq(pdev, 1);
		if (sport->err_irq < 0) {
			dev_err(&pdev->dev, "No sport status IRQ specified\n");
			ret = -ENOENT;
			goto out_error_unmap;
		}
#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
		res = platform_get_resource(pdev, IORESOURCE_IO, 0);
		if (res == NULL)
			sport->cts_pin = -1;
		else
			sport->cts_pin = res->start;

		res = platform_get_resource(pdev, IORESOURCE_IO, 1);
		if (res == NULL)
			sport->rts_pin = -1;
		else
			sport->rts_pin = res->start;

		if (sport->rts_pin >= 0)
			gpio_request(sport->rts_pin, DRV_NAME);
#endif
	}

#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
	if (!is_early_platform_device(pdev)) {
#endif
		sport = bfin_sport_uart_ports[pdev->id];
		sport->port.dev = &pdev->dev;
		dev_set_drvdata(&pdev->dev, sport);
		ret = uart_add_one_port(&sport_uart_reg, &sport->port);
#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
	}
#endif
	if (!ret)
		return 0;

	if (sport) {
out_error_unmap:
		iounmap(sport->port.membase);
out_error_free_peripherals:
		peripheral_free_list(
			(unsigned short *)pdev->dev.platform_data);
out_error_free_mem:
		kfree(sport);
		bfin_sport_uart_ports[pdev->id] = NULL;
	}

	return ret;
}

static int __devexit sport_uart_remove(struct platform_device *pdev)
{
	struct sport_uart_port *sport = platform_get_drvdata(pdev);

	dev_dbg(&pdev->dev, "%s enter\n", __func__);
	dev_set_drvdata(&pdev->dev, NULL);

	if (sport) {
		uart_remove_one_port(&sport_uart_reg, &sport->port);
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
		if (sport->rts_pin >= 0)
			gpio_free(sport->rts_pin);
#endif
		iounmap(sport->port.membase);
		peripheral_free_list(
			(unsigned short *)pdev->dev.platform_data);
		kfree(sport);
		bfin_sport_uart_ports[pdev->id] = NULL;
	}

	return 0;
}

static struct platform_driver sport_uart_driver = {
	.probe		= sport_uart_probe,
	.remove		= __devexit_p(sport_uart_remove),
	.driver		= {
		.name	= DRV_NAME,
#ifdef CONFIG_PM
		.pm	= &bfin_sport_uart_dev_pm_ops,
#endif
	},
};

#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
static __initdata struct early_platform_driver early_sport_uart_driver = {
	.class_str = CLASS_BFIN_SPORT_CONSOLE,
	.pdrv = &sport_uart_driver,
	.requested_id = EARLY_PLATFORM_ID_UNSET,
};

static int __init sport_uart_rs_console_init(void)
{
	early_platform_driver_register(&early_sport_uart_driver, DRV_NAME);

	early_platform_driver_probe(CLASS_BFIN_SPORT_CONSOLE,
		BFIN_SPORT_UART_MAX_PORTS, 0);

	register_console(&sport_uart_console);

	return 0;
}
console_initcall(sport_uart_rs_console_init);
#endif

static int __init sport_uart_init(void)
{
	int ret;

	pr_info("Blackfin uart over sport driver\n");

	ret = uart_register_driver(&sport_uart_reg);
	if (ret) {
		pr_err("failed to register %s:%d\n",
				sport_uart_reg.driver_name, ret);
		return ret;
	}

	ret = platform_driver_register(&sport_uart_driver);
	if (ret) {
		pr_err("failed to register sport uart driver:%d\n", ret);
		uart_unregister_driver(&sport_uart_reg);
	}

	return ret;
}
module_init(sport_uart_init);

static void __exit sport_uart_exit(void)
{
	platform_driver_unregister(&sport_uart_driver);
	uart_unregister_driver(&sport_uart_reg);
}
module_exit(sport_uart_exit);

MODULE_AUTHOR("Sonic Zhang, Roy Huang");
MODULE_DESCRIPTION("Blackfin serial over SPORT driver");
MODULE_LICENSE("GPL");