Free Electrons

Embedded Linux Experts

  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
/*
 * serial_ir.c
 *
 * serial_ir - Device driver that records pulse- and pause-lengths
 *	       (space-lengths) between DDCD event on a serial port.
 *
 * Copyright (C) 1996,97 Ralph Metzler <rjkm@thp.uni-koeln.de>
 * Copyright (C) 1998 Trent Piepho <xyzzy@u.washington.edu>
 * Copyright (C) 1998 Ben Pfaff <blp@gnu.org>
 * Copyright (C) 1999 Christoph Bartelmus <lirc@bartelmus.de>
 * Copyright (C) 2007 Andrei Tanas <andrei@tanas.ca> (suspend/resume support)
 * Copyright (C) 2016 Sean Young <sean@mess.org> (port to rc-core)
 *  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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/serial_reg.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <media/rc-core.h>

struct serial_ir_hw {
	int signal_pin;
	int signal_pin_change;
	u8 on;
	u8 off;
	unsigned set_send_carrier:1;
	unsigned set_duty_cycle:1;
	void (*send_pulse)(unsigned int length, ktime_t edge);
	void (*send_space)(void);
	spinlock_t lock;
};

#define IR_HOMEBREW	0
#define IR_IRDEO	1
#define IR_IRDEO_REMOTE	2
#define IR_ANIMAX	3
#define IR_IGOR		4

/* module parameters */
static int type;
static int io;
static int irq;
static ulong iommap;
static int ioshift;
static bool softcarrier = true;
static bool share_irq;
static int sense = -1;	/* -1 = auto, 0 = active high, 1 = active low */
static bool txsense;	/* 0 = active high, 1 = active low */

/* forward declarations */
static void send_pulse_irdeo(unsigned int length, ktime_t edge);
static void send_space_irdeo(void);
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
static void send_pulse_homebrew(unsigned int length, ktime_t edge);
static void send_space_homebrew(void);
#endif

static struct serial_ir_hw hardware[] = {
	[IR_HOMEBREW] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_HOMEBREW].lock),
		.signal_pin	   = UART_MSR_DCD,
		.signal_pin_change = UART_MSR_DDCD,
		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
		.off = (UART_MCR_RTS | UART_MCR_OUT2),
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
		.send_pulse = send_pulse_homebrew,
		.send_space = send_space_homebrew,
		.set_send_carrier = true,
		.set_duty_cycle = true,
#endif
	},

	[IR_IRDEO] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO].lock),
		.signal_pin	   = UART_MSR_DSR,
		.signal_pin_change = UART_MSR_DDSR,
		.on  = UART_MCR_OUT2,
		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
		.send_pulse = send_pulse_irdeo,
		.send_space = send_space_irdeo,
		.set_duty_cycle = true,
	},

	[IR_IRDEO_REMOTE] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO_REMOTE].lock),
		.signal_pin	   = UART_MSR_DSR,
		.signal_pin_change = UART_MSR_DDSR,
		.on  = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
		.send_pulse = send_pulse_irdeo,
		.send_space = send_space_irdeo,
		.set_duty_cycle = true,
	},

	[IR_ANIMAX] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_ANIMAX].lock),
		.signal_pin	   = UART_MSR_DCD,
		.signal_pin_change = UART_MSR_DDCD,
		.on  = 0,
		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
	},

	[IR_IGOR] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IGOR].lock),
		.signal_pin	   = UART_MSR_DSR,
		.signal_pin_change = UART_MSR_DDSR,
		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
		.off = (UART_MCR_RTS | UART_MCR_OUT2),
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
		.send_pulse = send_pulse_homebrew,
		.send_space = send_space_homebrew,
		.set_send_carrier = true,
		.set_duty_cycle = true,
#endif
	},
};

#define RS_ISR_PASS_LIMIT 256

struct serial_ir {
	ktime_t lastkt;
	struct rc_dev *rcdev;
	struct platform_device *pdev;
	struct timer_list timeout_timer;

	unsigned int carrier;
	unsigned int duty_cycle;
};

static struct serial_ir serial_ir;

/* fetch serial input packet (1 byte) from register offset */
static u8 sinp(int offset)
{
	if (iommap)
		/* the register is memory-mapped */
		offset <<= ioshift;

	return inb(io + offset);
}

/* write serial output packet (1 byte) of value to register offset */
static void soutp(int offset, u8 value)
{
	if (iommap)
		/* the register is memory-mapped */
		offset <<= ioshift;

	outb(value, io + offset);
}

static void on(void)
{
	if (txsense)
		soutp(UART_MCR, hardware[type].off);
	else
		soutp(UART_MCR, hardware[type].on);
}

static void off(void)
{
	if (txsense)
		soutp(UART_MCR, hardware[type].on);
	else
		soutp(UART_MCR, hardware[type].off);
}

static void send_pulse_irdeo(unsigned int length, ktime_t target)
{
	long rawbits;
	int i;
	unsigned char output;
	unsigned char chunk, shifted;

	/* how many bits have to be sent ? */
	rawbits = length * 1152 / 10000;
	if (serial_ir.duty_cycle > 50)
		chunk = 3;
	else
		chunk = 1;
	for (i = 0, output = 0x7f; rawbits > 0; rawbits -= 3) {
		shifted = chunk << (i * 3);
		shifted >>= 1;
		output &= (~shifted);
		i++;
		if (i == 3) {
			soutp(UART_TX, output);
			while (!(sinp(UART_LSR) & UART_LSR_THRE))
				;
			output = 0x7f;
			i = 0;
		}
	}
	if (i != 0) {
		soutp(UART_TX, output);
		while (!(sinp(UART_LSR) & UART_LSR_TEMT))
			;
	}
}

static void send_space_irdeo(void)
{
}

#ifdef CONFIG_IR_SERIAL_TRANSMITTER
static void send_pulse_homebrew_softcarrier(unsigned int length, ktime_t edge)
{
	ktime_t now, target = ktime_add_us(edge, length);
	/*
	 * delta should never exceed 4 seconds and on m68k
	 * ndelay(s64) does not compile; so use s32 rather than s64.
	 */
	s32 delta;
	unsigned int pulse, space;

	/* Ensure the dividend fits into 32 bit */
	pulse = DIV_ROUND_CLOSEST(serial_ir.duty_cycle * (NSEC_PER_SEC / 100),
				  serial_ir.carrier);
	space = DIV_ROUND_CLOSEST((100 - serial_ir.duty_cycle) *
				  (NSEC_PER_SEC / 100), serial_ir.carrier);

	for (;;) {
		now = ktime_get();
		if (ktime_compare(now, target) >= 0)
			break;
		on();
		edge = ktime_add_ns(edge, pulse);
		delta = ktime_to_ns(ktime_sub(edge, now));
		if (delta > 0)
			ndelay(delta);
		now = ktime_get();
		off();
		if (ktime_compare(now, target) >= 0)
			break;
		edge = ktime_add_ns(edge, space);
		delta = ktime_to_ns(ktime_sub(edge, now));
		if (delta > 0)
			ndelay(delta);
	}
}

static void send_pulse_homebrew(unsigned int length, ktime_t edge)
{
	if (softcarrier)
		send_pulse_homebrew_softcarrier(length, edge);
	else
		on();
}

static void send_space_homebrew(void)
{
	off();
}
#endif

static void frbwrite(unsigned int l, bool is_pulse)
{
	/* simple noise filter */
	static unsigned int ptr, pulse, space;
	DEFINE_IR_RAW_EVENT(ev);

	if (ptr > 0 && is_pulse) {
		pulse += l;
		if (pulse > 250000) {
			ev.duration = space;
			ev.pulse = false;
			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
			ev.duration = pulse;
			ev.pulse = true;
			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
			ptr = 0;
			pulse = 0;
		}
		return;
	}
	if (!is_pulse) {
		if (ptr == 0) {
			if (l > 20000000) {
				space = l;
				ptr++;
				return;
			}
		} else {
			if (l > 20000000) {
				space += pulse;
				if (space > IR_MAX_DURATION)
					space = IR_MAX_DURATION;
				space += l;
				if (space > IR_MAX_DURATION)
					space = IR_MAX_DURATION;
				pulse = 0;
				return;
			}

			ev.duration = space;
			ev.pulse = false;
			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
			ev.duration = pulse;
			ev.pulse = true;
			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
			ptr = 0;
			pulse = 0;
		}
	}

	ev.duration = l;
	ev.pulse = is_pulse;
	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
}

static irqreturn_t serial_ir_irq_handler(int i, void *blah)
{
	ktime_t kt;
	int counter, dcd;
	u8 status;
	ktime_t delkt;
	unsigned int data;
	static int last_dcd = -1;

	if ((sinp(UART_IIR) & UART_IIR_NO_INT)) {
		/* not our interrupt */
		return IRQ_NONE;
	}

	counter = 0;
	do {
		counter++;
		status = sinp(UART_MSR);
		if (counter > RS_ISR_PASS_LIMIT) {
			dev_err(&serial_ir.pdev->dev, "Trapped in interrupt");
			break;
		}
		if ((status & hardware[type].signal_pin_change) &&
		    sense != -1) {
			/* get current time */
			kt = ktime_get();

			/*
			 * The driver needs to know if your receiver is
			 * active high or active low, or the space/pulse
			 * sense could be inverted.
			 */

			/* calc time since last interrupt in nanoseconds */
			dcd = (status & hardware[type].signal_pin) ? 1 : 0;

			if (dcd == last_dcd) {
				dev_err(&serial_ir.pdev->dev,
					"ignoring spike: %d %d %lldns %lldns\n",
					dcd, sense, ktime_to_ns(kt),
					ktime_to_ns(serial_ir.lastkt));
				continue;
			}

			delkt = ktime_sub(kt, serial_ir.lastkt);
			if (ktime_compare(delkt, ktime_set(15, 0)) > 0) {
				data = IR_MAX_DURATION; /* really long time */
				if (!(dcd ^ sense)) {
					/* sanity check */
					dev_err(&serial_ir.pdev->dev,
						"dcd unexpected: %d %d %lldns %lldns\n",
						dcd, sense, ktime_to_ns(kt),
						ktime_to_ns(serial_ir.lastkt));
					/*
					 * detecting pulse while this
					 * MUST be a space!
					 */
					sense = sense ? 0 : 1;
				}
			} else {
				data = ktime_to_ns(delkt);
			}
			frbwrite(data, !(dcd ^ sense));
			serial_ir.lastkt = kt;
			last_dcd = dcd;
		}
	} while (!(sinp(UART_IIR) & UART_IIR_NO_INT)); /* still pending ? */

	mod_timer(&serial_ir.timeout_timer,
		  jiffies + nsecs_to_jiffies(serial_ir.rcdev->timeout));

	ir_raw_event_handle(serial_ir.rcdev);

	return IRQ_HANDLED;
}

static int hardware_init_port(void)
{
	u8 scratch, scratch2, scratch3;

	/*
	 * This is a simple port existence test, borrowed from the autoconfig
	 * function in drivers/tty/serial/8250/8250_port.c
	 */
	scratch = sinp(UART_IER);
	soutp(UART_IER, 0);
#ifdef __i386__
	outb(0xff, 0x080);
#endif
	scratch2 = sinp(UART_IER) & 0x0f;
	soutp(UART_IER, 0x0f);
#ifdef __i386__
	outb(0x00, 0x080);
#endif
	scratch3 = sinp(UART_IER) & 0x0f;
	soutp(UART_IER, scratch);
	if (scratch2 != 0 || scratch3 != 0x0f) {
		/* we fail, there's nothing here */
		pr_err("port existence test failed, cannot continue\n");
		return -ENODEV;
	}

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* First of all, disable all interrupts */
	soutp(UART_IER, sinp(UART_IER) &
	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));

	/* Clear registers. */
	sinp(UART_LSR);
	sinp(UART_RX);
	sinp(UART_IIR);
	sinp(UART_MSR);

	/* Set line for power source */
	off();

	/* Clear registers again to be sure. */
	sinp(UART_LSR);
	sinp(UART_RX);
	sinp(UART_IIR);
	sinp(UART_MSR);

	switch (type) {
	case IR_IRDEO:
	case IR_IRDEO_REMOTE:
		/* setup port to 7N1 @ 115200 Baud */
		/* 7N1+start = 9 bits at 115200 ~ 3 bits at 38kHz */

		/* Set DLAB 1. */
		soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);
		/* Set divisor to 1 => 115200 Baud */
		soutp(UART_DLM, 0);
		soutp(UART_DLL, 1);
		/* Set DLAB 0 +  7N1 */
		soutp(UART_LCR, UART_LCR_WLEN7);
		/* THR interrupt already disabled at this point */
		break;
	default:
		break;
	}

	return 0;
}

static void serial_ir_timeout(unsigned long arg)
{
	DEFINE_IR_RAW_EVENT(ev);

	ev.timeout = true;
	ev.duration = serial_ir.rcdev->timeout;
	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
	ir_raw_event_handle(serial_ir.rcdev);
}

/* Needed by serial_ir_probe() */
static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
			unsigned int count);
static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle);
static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier);
static int serial_ir_open(struct rc_dev *rcdev);
static void serial_ir_close(struct rc_dev *rcdev);

static int serial_ir_probe(struct platform_device *dev)
{
	struct rc_dev *rcdev;
	int i, nlow, nhigh, result;

	rcdev = devm_rc_allocate_device(&dev->dev, RC_DRIVER_IR_RAW);
	if (!rcdev)
		return -ENOMEM;

	if (hardware[type].send_pulse && hardware[type].send_space)
		rcdev->tx_ir = serial_ir_tx;
	if (hardware[type].set_send_carrier)
		rcdev->s_tx_carrier = serial_ir_tx_carrier;
	if (hardware[type].set_duty_cycle)
		rcdev->s_tx_duty_cycle = serial_ir_tx_duty_cycle;

	switch (type) {
	case IR_HOMEBREW:
		rcdev->device_name = "Serial IR type home-brew";
		break;
	case IR_IRDEO:
		rcdev->device_name = "Serial IR type IRdeo";
		break;
	case IR_IRDEO_REMOTE:
		rcdev->device_name = "Serial IR type IRdeo remote";
		break;
	case IR_ANIMAX:
		rcdev->device_name = "Serial IR type AnimaX";
		break;
	case IR_IGOR:
		rcdev->device_name = "Serial IR type IgorPlug";
		break;
	}

	rcdev->input_phys = KBUILD_MODNAME "/input0";
	rcdev->input_id.bustype = BUS_HOST;
	rcdev->input_id.vendor = 0x0001;
	rcdev->input_id.product = 0x0001;
	rcdev->input_id.version = 0x0100;
	rcdev->open = serial_ir_open;
	rcdev->close = serial_ir_close;
	rcdev->dev.parent = &serial_ir.pdev->dev;
	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
	rcdev->driver_name = KBUILD_MODNAME;
	rcdev->map_name = RC_MAP_RC6_MCE;
	rcdev->min_timeout = 1;
	rcdev->timeout = IR_DEFAULT_TIMEOUT;
	rcdev->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
	rcdev->rx_resolution = 250000;

	serial_ir.rcdev = rcdev;

	setup_timer(&serial_ir.timeout_timer, serial_ir_timeout,
		    (unsigned long)&serial_ir);

	result = devm_request_irq(&dev->dev, irq, serial_ir_irq_handler,
				  share_irq ? IRQF_SHARED : 0,
				  KBUILD_MODNAME, &hardware);
	if (result < 0) {
		if (result == -EBUSY)
			dev_err(&dev->dev, "IRQ %d busy\n", irq);
		else if (result == -EINVAL)
			dev_err(&dev->dev, "Bad irq number or handler\n");
		return result;
	}

	/* Reserve io region. */
	if ((iommap &&
	     (devm_request_mem_region(&dev->dev, iommap, 8 << ioshift,
				      KBUILD_MODNAME) == NULL)) ||
	     (!iommap && (devm_request_region(&dev->dev, io, 8,
			  KBUILD_MODNAME) == NULL))) {
		dev_err(&dev->dev, "port %04x already in use\n", io);
		dev_warn(&dev->dev, "use 'setserial /dev/ttySX uart none'\n");
		dev_warn(&dev->dev,
			 "or compile the serial port driver as module and\n");
		dev_warn(&dev->dev, "make sure this module is loaded first\n");
		return -EBUSY;
	}

	result = hardware_init_port();
	if (result < 0)
		return result;

	/* Initialize pulse/space widths */
	serial_ir.duty_cycle = 50;
	serial_ir.carrier = 38000;

	/* If pin is high, then this must be an active low receiver. */
	if (sense == -1) {
		/* wait 1/2 sec for the power supply */
		msleep(500);

		/*
		 * probe 9 times every 0.04s, collect "votes" for
		 * active high/low
		 */
		nlow = 0;
		nhigh = 0;
		for (i = 0; i < 9; i++) {
			if (sinp(UART_MSR) & hardware[type].signal_pin)
				nlow++;
			else
				nhigh++;
			msleep(40);
		}
		sense = nlow >= nhigh ? 1 : 0;
		dev_info(&dev->dev, "auto-detected active %s receiver\n",
			 sense ? "low" : "high");
	} else
		dev_info(&dev->dev, "Manually using active %s receiver\n",
			 sense ? "low" : "high");

	dev_dbg(&dev->dev, "Interrupt %d, port %04x obtained\n", irq, io);

	return devm_rc_register_device(&dev->dev, rcdev);
}

static int serial_ir_open(struct rc_dev *rcdev)
{
	unsigned long flags;

	/* initialize timestamp */
	serial_ir.lastkt = ktime_get();

	spin_lock_irqsave(&hardware[type].lock, flags);

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);

	spin_unlock_irqrestore(&hardware[type].lock, flags);

	return 0;
}

static void serial_ir_close(struct rc_dev *rcdev)
{
	unsigned long flags;

	spin_lock_irqsave(&hardware[type].lock, flags);

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* First of all, disable all interrupts */
	soutp(UART_IER, sinp(UART_IER) &
	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
	spin_unlock_irqrestore(&hardware[type].lock, flags);
}

static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
			unsigned int count)
{
	unsigned long flags;
	ktime_t edge;
	s64 delta;
	int i;

	spin_lock_irqsave(&hardware[type].lock, flags);
	if (type == IR_IRDEO) {
		/* DTR, RTS down */
		on();
	}

	edge = ktime_get();
	for (i = 0; i < count; i++) {
		if (i % 2)
			hardware[type].send_space();
		else
			hardware[type].send_pulse(txbuf[i], edge);

		edge = ktime_add_us(edge, txbuf[i]);
		delta = ktime_us_delta(edge, ktime_get());
		if (delta > 25) {
			spin_unlock_irqrestore(&hardware[type].lock, flags);
			usleep_range(delta - 25, delta + 25);
			spin_lock_irqsave(&hardware[type].lock, flags);
		} else if (delta > 0) {
			udelay(delta);
		}
	}
	off();
	spin_unlock_irqrestore(&hardware[type].lock, flags);
	return count;
}

static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle)
{
	serial_ir.duty_cycle = cycle;
	return 0;
}

static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier)
{
	if (carrier > 500000 || carrier < 20000)
		return -EINVAL;

	serial_ir.carrier = carrier;
	return 0;
}

static int serial_ir_suspend(struct platform_device *dev,
			     pm_message_t state)
{
	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* Disable all interrupts */
	soutp(UART_IER, sinp(UART_IER) &
	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));

	/* Clear registers. */
	sinp(UART_LSR);
	sinp(UART_RX);
	sinp(UART_IIR);
	sinp(UART_MSR);

	return 0;
}

static int serial_ir_resume(struct platform_device *dev)
{
	unsigned long flags;
	int result;

	result = hardware_init_port();
	if (result < 0)
		return result;

	spin_lock_irqsave(&hardware[type].lock, flags);
	/* Enable Interrupt */
	serial_ir.lastkt = ktime_get();
	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
	off();

	spin_unlock_irqrestore(&hardware[type].lock, flags);

	return 0;
}

static struct platform_driver serial_ir_driver = {
	.probe		= serial_ir_probe,
	.suspend	= serial_ir_suspend,
	.resume		= serial_ir_resume,
	.driver		= {
		.name	= "serial_ir",
	},
};

static int __init serial_ir_init(void)
{
	int result;

	result = platform_driver_register(&serial_ir_driver);
	if (result)
		return result;

	serial_ir.pdev = platform_device_alloc("serial_ir", 0);
	if (!serial_ir.pdev) {
		result = -ENOMEM;
		goto exit_driver_unregister;
	}

	result = platform_device_add(serial_ir.pdev);
	if (result)
		goto exit_device_put;

	return 0;

exit_device_put:
	platform_device_put(serial_ir.pdev);
exit_driver_unregister:
	platform_driver_unregister(&serial_ir_driver);
	return result;
}

static void serial_ir_exit(void)
{
	platform_device_unregister(serial_ir.pdev);
	platform_driver_unregister(&serial_ir_driver);
}

static int __init serial_ir_init_module(void)
{
	int result;

	switch (type) {
	case IR_HOMEBREW:
	case IR_IRDEO:
	case IR_IRDEO_REMOTE:
	case IR_ANIMAX:
	case IR_IGOR:
		/* if nothing specified, use ttyS0/com1 and irq 4 */
		io = io ? io : 0x3f8;
		irq = irq ? irq : 4;
		break;
	default:
		return -EINVAL;
	}
	if (!softcarrier) {
		switch (type) {
		case IR_HOMEBREW:
		case IR_IGOR:
			hardware[type].set_send_carrier = false;
			hardware[type].set_duty_cycle = false;
			break;
		}
	}

	/* make sure sense is either -1, 0, or 1 */
	if (sense != -1)
		sense = !!sense;

	result = serial_ir_init();
	if (!result)
		return 0;

	serial_ir_exit();
	return result;
}

static void __exit serial_ir_exit_module(void)
{
	del_timer_sync(&serial_ir.timeout_timer);
	serial_ir_exit();
}

module_init(serial_ir_init_module);
module_exit(serial_ir_exit_module);

MODULE_DESCRIPTION("Infra-red receiver driver for serial ports.");
MODULE_AUTHOR("Ralph Metzler, Trent Piepho, Ben Pfaff, Christoph Bartelmus, Andrei Tanas");
MODULE_LICENSE("GPL");

module_param(type, int, 0444);
MODULE_PARM_DESC(type, "Hardware type (0 = home-brew, 1 = IRdeo, 2 = IRdeo Remote, 3 = AnimaX, 4 = IgorPlug");

module_param_hw(io, int, ioport, 0444);
MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");

/* some architectures (e.g. intel xscale) have memory mapped registers */
module_param_hw(iommap, ulong, other, 0444);
MODULE_PARM_DESC(iommap, "physical base for memory mapped I/O (0 = no memory mapped io)");

/*
 * some architectures (e.g. intel xscale) align the 8bit serial registers
 * on 32bit word boundaries.
 * See linux-kernel/drivers/tty/serial/8250/8250.c serial_in()/out()
 */
module_param_hw(ioshift, int, other, 0444);
MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");

module_param_hw(irq, int, irq, 0444);
MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");

module_param_hw(share_irq, bool, other, 0444);
MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");

module_param(sense, int, 0444);
MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit (0 = active high, 1 = active low )");

#ifdef CONFIG_IR_SERIAL_TRANSMITTER
module_param(txsense, bool, 0444);
MODULE_PARM_DESC(txsense, "Sense of transmitter circuit (0 = active high, 1 = active low )");
#endif

module_param(softcarrier, bool, 0444);
MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");