aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/serial/amba-pl010.c
blob: cdc049d4350fc20aa684eb2d4387772c6b39a0f7 (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
/*
 *  linux/drivers/char/amba.c
 *
 *  Driver for AMBA serial ports
 *
 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
 *
 *  Copyright 1999 ARM Limited
 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
 *
 * 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
 *
 * This is a generic driver for ARM AMBA-type serial ports.  They
 * have a lot of 16550-like features, but are not register compatible.
 * Note that although they do have CTS, DCD and DSR inputs, they do
 * not have an RI input, nor do they have DTR or RTS outputs.  If
 * required, these have to be supplied via some other means (eg, GPIO)
 * and hooked into this driver.
 */

#if defined(CONFIG_SERIAL_AMBA_PL010_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/amba/bus.h>
#include <linux/amba/serial.h>
#include <linux/clk.h>

#include <asm/io.h>

#define UART_NR		8

#define SERIAL_AMBA_MAJOR	204
#define SERIAL_AMBA_MINOR	16
#define SERIAL_AMBA_NR		UART_NR

#define AMBA_ISR_PASS_LIMIT	256

#define UART_RX_DATA(s)		(((s) & UART01x_FR_RXFE) == 0)
#define UART_TX_READY(s)	(((s) & UART01x_FR_TXFF) == 0)

#define UART_DUMMY_RSR_RX	256
#define UART_PORT_SIZE		64

/*
 * We wrap our port structure around the generic uart_port.
 */
struct uart_amba_port {
	struct uart_port	port;
	struct clk		*clk;
	struct amba_device	*dev;
	struct amba_pl010_data	*data;
	unsigned int		old_status;
};

static void pl010_stop_tx(struct uart_port *port)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr &= ~UART010_CR_TIE;
	writel(cr, uap->port.membase + UART010_CR);
}

static void pl010_start_tx(struct uart_port *port)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr |= UART010_CR_TIE;
	writel(cr, uap->port.membase + UART010_CR);
}

static void pl010_stop_rx(struct uart_port *port)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
	writel(cr, uap->port.membase + UART010_CR);
}

static void pl010_enable_ms(struct uart_port *port)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr |= UART010_CR_MSIE;
	writel(cr, uap->port.membase + UART010_CR);
}

static void pl010_rx_chars(struct uart_amba_port *uap)
{
	struct tty_struct *tty = uap->port.info->port.tty;
	unsigned int status, ch, flag, rsr, max_count = 256;

	status = readb(uap->port.membase + UART01x_FR);
	while (UART_RX_DATA(status) && max_count--) {
		ch = readb(uap->port.membase + UART01x_DR);
		flag = TTY_NORMAL;

		uap->port.icount.rx++;

		/*
		 * Note that the error handling code is
		 * out of the main execution path
		 */
		rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
		if (unlikely(rsr & UART01x_RSR_ANY)) {
			writel(0, uap->port.membase + UART01x_ECR);

			if (rsr & UART01x_RSR_BE) {
				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
				uap->port.icount.brk++;
				if (uart_handle_break(&uap->port))
					goto ignore_char;
			} else if (rsr & UART01x_RSR_PE)
				uap->port.icount.parity++;
			else if (rsr & UART01x_RSR_FE)
				uap->port.icount.frame++;
			if (rsr & UART01x_RSR_OE)
				uap->port.icount.overrun++;

			rsr &= uap->port.read_status_mask;

			if (rsr & UART01x_RSR_BE)
				flag = TTY_BREAK;
			else if (rsr & UART01x_RSR_PE)
				flag = TTY_PARITY;
			else if (rsr & UART01x_RSR_FE)
				flag = TTY_FRAME;
		}

		if (uart_handle_sysrq_char(&uap->port, ch))
			goto ignore_char;

		uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);

	ignore_char:
		status = readb(uap->port.membase + UART01x_FR);
	}
	spin_unlock(&uap->port.lock);
	tty_flip_buffer_push(tty);
	spin_lock(&uap->port.lock);
}

static void pl010_tx_chars(struct uart_amba_port *uap)
{
	struct circ_buf *xmit = &uap->port.info->xmit;
	int count;

	if (uap->port.x_char) {
		writel(uap->port.x_char, uap->port.membase + UART01x_DR);
		uap->port.icount.tx++;
		uap->port.x_char = 0;
		return;
	}
	if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
		pl010_stop_tx(&uap->port);
		return;
	}

	count = uap->port.fifosize >> 1;
	do {
		writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		uap->port.icount.tx++;
		if (uart_circ_empty(xmit))
			break;
	} while (--count > 0);

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

	if (uart_circ_empty(xmit))
		pl010_stop_tx(&uap->port);
}

static void pl010_modem_status(struct uart_amba_port *uap)
{
	unsigned int status, delta;

	writel(0, uap->port.membase + UART010_ICR);

	status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;

	delta = status ^ uap->old_status;
	uap->old_status = status;

	if (!delta)
		return;

	if (delta & UART01x_FR_DCD)
		uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);

	if (delta & UART01x_FR_DSR)
		uap->port.icount.dsr++;

	if (delta & UART01x_FR_CTS)
		uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);

	wake_up_interruptible(&uap->port.info->delta_msr_wait);
}

static irqreturn_t pl010_int(int irq, void *dev_id)
{
	struct uart_amba_port *uap = dev_id;
	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
	int handled = 0;

	spin_lock(&uap->port.lock);

	status = readb(uap->port.membase + UART010_IIR);
	if (status) {
		do {
			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
				pl010_rx_chars(uap);
			if (status & UART010_IIR_MIS)
				pl010_modem_status(uap);
			if (status & UART010_IIR_TIS)
				pl010_tx_chars(uap);

			if (pass_counter-- == 0)
				break;

			status = readb(uap->port.membase + UART010_IIR);
		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
				   UART010_IIR_TIS));
		handled = 1;
	}

	spin_unlock(&uap->port.lock);

	return IRQ_RETVAL(handled);
}

static unsigned int pl010_tx_empty(struct uart_port *port)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int status = readb(uap->port.membase + UART01x_FR);
	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
}

static unsigned int pl010_get_mctrl(struct uart_port *port)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int result = 0;
	unsigned int status;

	status = readb(uap->port.membase + UART01x_FR);
	if (status & UART01x_FR_DCD)
		result |= TIOCM_CAR;
	if (status & UART01x_FR_DSR)
		result |= TIOCM_DSR;
	if (status & UART01x_FR_CTS)
		result |= TIOCM_CTS;

	return result;
}

static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;

	if (uap->data)
		uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
}

static void pl010_break_ctl(struct uart_port *port, int break_state)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned long flags;
	unsigned int lcr_h;

	spin_lock_irqsave(&uap->port.lock, flags);
	lcr_h = readb(uap->port.membase + UART010_LCRH);
	if (break_state == -1)
		lcr_h |= UART01x_LCRH_BRK;
	else
		lcr_h &= ~UART01x_LCRH_BRK;
	writel(lcr_h, uap->port.membase + UART010_LCRH);
	spin_unlock_irqrestore(&uap->port.lock, flags);
}

static int pl010_startup(struct uart_port *port)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	int retval;

	/*
	 * Try to enable the clock producer.
	 */
	retval = clk_enable(uap->clk);
	if (retval)
		goto out;

	uap->port.uartclk = clk_get_rate(uap->clk);

	/*
	 * Allocate the IRQ
	 */
	retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
	if (retval)
		goto clk_dis;

	/*
	 * initialise the old status of the modem signals
	 */
	uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;

	/*
	 * Finally, enable interrupts
	 */
	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
	       uap->port.membase + UART010_CR);

	return 0;

 clk_dis:
	clk_disable(uap->clk);
 out:
	return retval;
}

static void pl010_shutdown(struct uart_port *port)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;

	/*
	 * Free the interrupt
	 */
	free_irq(uap->port.irq, uap);

	/*
	 * disable all interrupts, disable the port
	 */
	writel(0, uap->port.membase + UART010_CR);

	/* disable break condition and fifos */
	writel(readb(uap->port.membase + UART010_LCRH) &
		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
	       uap->port.membase + UART010_LCRH);

	/*
	 * Shut down the clock producer
	 */
	clk_disable(uap->clk);
}

static void
pl010_set_termios(struct uart_port *port, struct ktermios *termios,
		     struct ktermios *old)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int lcr_h, old_cr;
	unsigned long flags;
	unsigned int baud, quot;

	/*
	 * Ask the core to calculate the divisor for us.
	 */
	baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16); 
	quot = uart_get_divisor(port, baud);

	switch (termios->c_cflag & CSIZE) {
	case CS5:
		lcr_h = UART01x_LCRH_WLEN_5;
		break;
	case CS6:
		lcr_h = UART01x_LCRH_WLEN_6;
		break;
	case CS7:
		lcr_h = UART01x_LCRH_WLEN_7;
		break;
	default: // CS8
		lcr_h = UART01x_LCRH_WLEN_8;
		break;
	}
	if (termios->c_cflag & CSTOPB)
		lcr_h |= UART01x_LCRH_STP2;
	if (termios->c_cflag & PARENB) {
		lcr_h |= UART01x_LCRH_PEN;
		if (!(termios->c_cflag & PARODD))
			lcr_h |= UART01x_LCRH_EPS;
	}
	if (uap->port.fifosize > 1)
		lcr_h |= UART01x_LCRH_FEN;

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

	/*
	 * Update the per-port timeout.
	 */
	uart_update_timeout(port, termios->c_cflag, baud);

	uap->port.read_status_mask = UART01x_RSR_OE;
	if (termios->c_iflag & INPCK)
		uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
	if (termios->c_iflag & (BRKINT | PARMRK))
		uap->port.read_status_mask |= UART01x_RSR_BE;

	/*
	 * Characters to ignore
	 */
	uap->port.ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
	if (termios->c_iflag & IGNBRK) {
		uap->port.ignore_status_mask |= UART01x_RSR_BE;
		/*
		 * If we're ignoring parity and break indicators,
		 * ignore overruns too (for real raw support).
		 */
		if (termios->c_iflag & IGNPAR)
			uap->port.ignore_status_mask |= UART01x_RSR_OE;
	}

	/*
	 * Ignore all characters if CREAD is not set.
	 */
	if ((termios->c_cflag & CREAD) == 0)
		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;

	/* first, disable everything */
	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;

	if (UART_ENABLE_MS(port, termios->c_cflag))
		old_cr |= UART010_CR_MSIE;

	writel(0, uap->port.membase + UART010_CR);

	/* Set baud rate */
	quot -= 1;
	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
	writel(quot & 0xff, uap->port.membase + UART010_LCRL);

	/*
	 * ----------v----------v----------v----------v-----
	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
	 * ----------^----------^----------^----------^-----
	 */
	writel(lcr_h, uap->port.membase + UART010_LCRH);
	writel(old_cr, uap->port.membase + UART010_CR);

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

static const char *pl010_type(struct uart_port *port)
{
	return port->type == PORT_AMBA ? "AMBA" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'
 */
static void pl010_release_port(struct uart_port *port)
{
	release_mem_region(port->mapbase, UART_PORT_SIZE);
}

/*
 * Request the memory region(s) being used by 'port'
 */
static int pl010_request_port(struct uart_port *port)
{
	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
			!= NULL ? 0 : -EBUSY;
}

/*
 * Configure/autoconfigure the port.
 */
static void pl010_config_port(struct uart_port *port, int flags)
{
	if (flags & UART_CONFIG_TYPE) {
		port->type = PORT_AMBA;
		pl010_request_port(port);
	}
}

/*
 * verify the new serial_struct (for TIOCSSERIAL).
 */
static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	int ret = 0;
	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
		ret = -EINVAL;
	if (ser->irq < 0 || ser->irq >= nr_irqs)
		ret = -EINVAL;
	if (ser->baud_base < 9600)
		ret = -EINVAL;
	return ret;
}

static struct uart_ops amba_pl010_pops = {
	.tx_empty	= pl010_tx_empty,
	.set_mctrl	= pl010_set_mctrl,
	.get_mctrl	= pl010_get_mctrl,
	.stop_tx	= pl010_stop_tx,
	.start_tx	= pl010_start_tx,
	.stop_rx	= pl010_stop_rx,
	.enable_ms	= pl010_enable_ms,
	.break_ctl	= pl010_break_ctl,
	.startup	= pl010_startup,
	.shutdown	= pl010_shutdown,
	.set_termios	= pl010_set_termios,
	.type		= pl010_type,
	.release_port	= pl010_release_port,
	.request_port	= pl010_request_port,
	.config_port	= pl010_config_port,
	.verify_port	= pl010_verify_port,
};

static struct uart_amba_port *amba_ports[UART_NR];

#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE

static void pl010_console_putchar(struct uart_port *port, int ch)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int status;

	do {
		status = readb(uap->port.membase + UART01x_FR);
		barrier();
	} while (!UART_TX_READY(status));
	writel(ch, uap->port.membase + UART01x_DR);
}

static void
pl010_console_write(struct console *co, const char *s, unsigned int count)
{
	struct uart_amba_port *uap = amba_ports[co->index];
	unsigned int status, old_cr;

	clk_enable(uap->clk);

	/*
	 *	First save the CR then disable the interrupts
	 */
	old_cr = readb(uap->port.membase + UART010_CR);
	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);

	uart_console_write(&uap->port, s, count, pl010_console_putchar);

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore the TCR
	 */
	do {
		status = readb(uap->port.membase + UART01x_FR);
		barrier();
	} while (status & UART01x_FR_BUSY);
	writel(old_cr, uap->port.membase + UART010_CR);

	clk_disable(uap->clk);
}

static void __init
pl010_console_get_options(struct uart_amba_port *uap, int *baud,
			     int *parity, int *bits)
{
	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
		unsigned int lcr_h, quot;
		lcr_h = readb(uap->port.membase + UART010_LCRH);

		*parity = 'n';
		if (lcr_h & UART01x_LCRH_PEN) {
			if (lcr_h & UART01x_LCRH_EPS)
				*parity = 'e';
			else
				*parity = 'o';
		}

		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
			*bits = 7;
		else
			*bits = 8;

		quot = readb(uap->port.membase + UART010_LCRL) |
		       readb(uap->port.membase + UART010_LCRM) << 8;
		*baud = uap->port.uartclk / (16 * (quot + 1));
	}
}

static int __init pl010_console_setup(struct console *co, char *options)
{
	struct uart_amba_port *uap;
	int baud = 38400;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	/*
	 * Check whether an invalid uart number has been specified, and
	 * if so, search for the first available port that does have
	 * console support.
	 */
	if (co->index >= UART_NR)
		co->index = 0;
	uap = amba_ports[co->index];
	if (!uap)
		return -ENODEV;

	uap->port.uartclk = clk_get_rate(uap->clk);

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);
	else
		pl010_console_get_options(uap, &baud, &parity, &bits);

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

static struct uart_driver amba_reg;
static struct console amba_console = {
	.name		= "ttyAM",
	.write		= pl010_console_write,
	.device		= uart_console_device,
	.setup		= pl010_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &amba_reg,
};

#define AMBA_CONSOLE	&amba_console
#else
#define AMBA_CONSOLE	NULL
#endif

static struct uart_driver amba_reg = {
	.owner			= THIS_MODULE,
	.driver_name		= "ttyAM",
	.dev_name		= "ttyAM",
	.major			= SERIAL_AMBA_MAJOR,
	.minor			= SERIAL_AMBA_MINOR,
	.nr			= UART_NR,
	.cons			= AMBA_CONSOLE,
};

static int pl010_probe(struct amba_device *dev, struct amba_id *id)
{
	struct uart_amba_port *uap;
	void __iomem *base;
	int i, ret;

	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
		if (amba_ports[i] == NULL)
			break;

	if (i == ARRAY_SIZE(amba_ports)) {
		ret = -EBUSY;
		goto out;
	}

	uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
	if (!uap) {
		ret = -ENOMEM;
		goto out;
	}

	base = ioremap(dev->res.start, PAGE_SIZE);
	if (!base) {
		ret = -ENOMEM;
		goto free;
	}

	uap->clk = clk_get(&dev->dev, NULL);
	if (IS_ERR(uap->clk)) {
		ret = PTR_ERR(uap->clk);
		goto unmap;
	}

	uap->port.dev = &dev->dev;
	uap->port.mapbase = dev->res.start;
	uap->port.membase = base;
	uap->port.iotype = UPIO_MEM;
	uap->port.irq = dev->irq[0];
	uap->port.fifosize = 16;
	uap->port.ops = &amba_pl010_pops;
	uap->port.flags = UPF_BOOT_AUTOCONF;
	uap->port.line = i;
	uap->dev = dev;
	uap->data = dev->dev.platform_data;

	amba_ports[i] = uap;

	amba_set_drvdata(dev, uap);
	ret = uart_add_one_port(&amba_reg, &uap->port);
	if (ret) {
		amba_set_drvdata(dev, NULL);
		amba_ports[i] = NULL;
		clk_put(uap->clk);
 unmap:
		iounmap(base);
 free:
		kfree(uap);
	}
 out:
	return ret;
}

static int pl010_remove(struct amba_device *dev)
{
	struct uart_amba_port *uap = amba_get_drvdata(dev);
	int i;

	amba_set_drvdata(dev, NULL);

	uart_remove_one_port(&amba_reg, &uap->port);

	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
		if (amba_ports[i] == uap)
			amba_ports[i] = NULL;

	iounmap(uap->port.membase);
	clk_put(uap->clk);
	kfree(uap);
	return 0;
}

static int pl010_suspend(struct amba_device *dev, pm_message_t state)
{
	struct uart_amba_port *uap = amba_get_drvdata(dev);

	if (uap)
		uart_suspend_port(&amba_reg, &uap->port);

	return 0;
}

static int pl010_resume(struct amba_device *dev)
{
	struct uart_amba_port *uap = amba_get_drvdata(dev);

	if (uap)
		uart_resume_port(&amba_reg, &uap->port);

	return 0;
}

static struct amba_id pl010_ids[] __initdata = {
	{
		.id	= 0x00041010,
		.mask	= 0x000fffff,
	},
	{ 0, 0 },
};

static struct amba_driver pl010_driver = {
	.drv = {
		.name	= "uart-pl010",
	},
	.id_table	= pl010_ids,
	.probe		= pl010_probe,
	.remove		= pl010_remove,
	.suspend	= pl010_suspend,
	.resume		= pl010_resume,
};

static int __init pl010_init(void)
{
	int ret;

	printk(KERN_INFO "Serial: AMBA driver\n");

	ret = uart_register_driver(&amba_reg);
	if (ret == 0) {
		ret = amba_driver_register(&pl010_driver);
		if (ret)
			uart_unregister_driver(&amba_reg);
	}
	return ret;
}

static void __exit pl010_exit(void)
{
	amba_driver_unregister(&pl010_driver);
	uart_unregister_driver(&amba_reg);
}

module_init(pl010_init);
module_exit(pl010_exit);

MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
MODULE_DESCRIPTION("ARM AMBA serial port driver");
MODULE_LICENSE("GPL");