summaryrefslogtreecommitdiffstats
path: root/drivers/net/irda/sa1100_ir.c
blob: 06883309916d493636097dddc1e5b15e93359cf5 (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
/*
 *  linux/drivers/net/irda/sa1100_ir.c
 *
 *  Copyright (C) 2000-2001 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  Infra-red driver for the StrongARM SA1100 embedded microprocessor
 *
 *  Note that we don't have to worry about the SA1111's DMA bugs in here,
 *  so we use the straight forward dma_map_* functions with a null pointer.
 *
 *  This driver takes one kernel command line parameter, sa1100ir=, with
 *  the following options:
 *	max_rate:baudrate	- set the maximum baud rate
 *	power_leve:level	- set the transmitter power level
 *	tx_lpm:0|1		- set transmit low power mode
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/rtnetlink.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>

#include <net/irda/irda.h>
#include <net/irda/wrapper.h>
#include <net/irda/irda_device.h>

#include <asm/irq.h>
#include <asm/dma.h>
#include <asm/hardware.h>
#include <asm/mach/irda.h>

static int power_level = 3;
static int tx_lpm;
static int max_rate = 4000000;

struct sa1100_irda {
	unsigned char		hscr0;
	unsigned char		utcr4;
	unsigned char		power;
	unsigned char		open;

	int			speed;
	int			newspeed;

	struct sk_buff		*txskb;
	struct sk_buff		*rxskb;
	dma_addr_t		txbuf_dma;
	dma_addr_t		rxbuf_dma;
	dma_regs_t		*txdma;
	dma_regs_t		*rxdma;

	struct net_device_stats	stats;
	struct device		*dev;
	struct irda_platform_data *pdata;
	struct irlap_cb		*irlap;
	struct qos_info		qos;

	iobuff_t		tx_buff;
	iobuff_t		rx_buff;
};

#define IS_FIR(si)		((si)->speed >= 4000000)

#define HPSIR_MAX_RXLEN		2047

/*
 * Allocate and map the receive buffer, unless it is already allocated.
 */
static int sa1100_irda_rx_alloc(struct sa1100_irda *si)
{
	if (si->rxskb)
		return 0;

	si->rxskb = alloc_skb(HPSIR_MAX_RXLEN + 1, GFP_ATOMIC);

	if (!si->rxskb) {
		printk(KERN_ERR "sa1100_ir: out of memory for RX SKB\n");
		return -ENOMEM;
	}

	/*
	 * Align any IP headers that may be contained
	 * within the frame.
	 */
	skb_reserve(si->rxskb, 1);

	si->rxbuf_dma = dma_map_single(si->dev, si->rxskb->data,
					HPSIR_MAX_RXLEN,
					DMA_FROM_DEVICE);
	return 0;
}

/*
 * We want to get here as soon as possible, and get the receiver setup.
 * We use the existing buffer.
 */
static void sa1100_irda_rx_dma_start(struct sa1100_irda *si)
{
	if (!si->rxskb) {
		printk(KERN_ERR "sa1100_ir: rx buffer went missing\n");
		return;
	}

	/*
	 * First empty receive FIFO
	 */
	Ser2HSCR0 = si->hscr0 | HSCR0_HSSP;

	/*
	 * Enable the DMA, receiver and receive interrupt.
	 */
	sa1100_clear_dma(si->rxdma);
	sa1100_start_dma(si->rxdma, si->rxbuf_dma, HPSIR_MAX_RXLEN);
	Ser2HSCR0 = si->hscr0 | HSCR0_HSSP | HSCR0_RXE;
}

/*
 * Set the IrDA communications speed.
 */
static int sa1100_irda_set_speed(struct sa1100_irda *si, int speed)
{
	unsigned long flags;
	int brd, ret = -EINVAL;

	switch (speed) {
	case 9600:	case 19200:	case 38400:
	case 57600:	case 115200:
		brd = 3686400 / (16 * speed) - 1;

		/*
		 * Stop the receive DMA.
		 */
		if (IS_FIR(si))
			sa1100_stop_dma(si->rxdma);

		local_irq_save(flags);

		Ser2UTCR3 = 0;
		Ser2HSCR0 = HSCR0_UART;

		Ser2UTCR1 = brd >> 8;
		Ser2UTCR2 = brd;

		/*
		 * Clear status register
		 */
		Ser2UTSR0 = UTSR0_REB | UTSR0_RBB | UTSR0_RID;
		Ser2UTCR3 = UTCR3_RIE | UTCR3_RXE | UTCR3_TXE;

		if (si->pdata->set_speed)
			si->pdata->set_speed(si->dev, speed);

		si->speed = speed;

		local_irq_restore(flags);
		ret = 0;
		break;

	case 4000000:
		local_irq_save(flags);

		si->hscr0 = 0;

		Ser2HSSR0 = 0xff;
		Ser2HSCR0 = si->hscr0 | HSCR0_HSSP;
		Ser2UTCR3 = 0;

		si->speed = speed;

		if (si->pdata->set_speed)
			si->pdata->set_speed(si->dev, speed);

		sa1100_irda_rx_alloc(si);
		sa1100_irda_rx_dma_start(si);

		local_irq_restore(flags);

		break;

	default:
		break;
	}

	return ret;
}

/*
 * Control the power state of the IrDA transmitter.
 * State:
 *  0 - off
 *  1 - short range, lowest power
 *  2 - medium range, medium power
 *  3 - maximum range, high power
 *
 * Currently, only assabet is known to support this.
 */
static int
__sa1100_irda_set_power(struct sa1100_irda *si, unsigned int state)
{
	int ret = 0;
	if (si->pdata->set_power)
		ret = si->pdata->set_power(si->dev, state);
	return ret;
}

static inline int
sa1100_set_power(struct sa1100_irda *si, unsigned int state)
{
	int ret;

	ret = __sa1100_irda_set_power(si, state);
	if (ret == 0)
		si->power = state;

	return ret;
}

static int sa1100_irda_startup(struct sa1100_irda *si)
{
	int ret;

	/*
	 * Ensure that the ports for this device are setup correctly.
	 */
	if (si->pdata->startup)
		si->pdata->startup(si->dev);

	/*
	 * Configure PPC for IRDA - we want to drive TXD2 low.
	 * We also want to drive this pin low during sleep.
	 */
	PPSR &= ~PPC_TXD2;
	PSDR &= ~PPC_TXD2;
	PPDR |= PPC_TXD2;

	/*
	 * Enable HP-SIR modulation, and ensure that the port is disabled.
	 */
	Ser2UTCR3 = 0;
	Ser2HSCR0 = HSCR0_UART;
	Ser2UTCR4 = si->utcr4;
	Ser2UTCR0 = UTCR0_8BitData;
	Ser2HSCR2 = HSCR2_TrDataH | HSCR2_RcDataL;

	/*
	 * Clear status register
	 */
	Ser2UTSR0 = UTSR0_REB | UTSR0_RBB | UTSR0_RID;

	ret = sa1100_irda_set_speed(si, si->speed = 9600);
	if (ret) {
		Ser2UTCR3 = 0;
		Ser2HSCR0 = 0;

		if (si->pdata->shutdown)
			si->pdata->shutdown(si->dev);
	}

	return ret;
}

static void sa1100_irda_shutdown(struct sa1100_irda *si)
{
	/*
	 * Stop all DMA activity.
	 */
	sa1100_stop_dma(si->rxdma);
	sa1100_stop_dma(si->txdma);

	/* Disable the port. */
	Ser2UTCR3 = 0;
	Ser2HSCR0 = 0;

	if (si->pdata->shutdown)
		si->pdata->shutdown(si->dev);
}

#ifdef CONFIG_PM
/*
 * Suspend the IrDA interface.
 */
static int sa1100_irda_suspend(struct device *_dev, pm_message_t state)
{
	struct net_device *dev = dev_get_drvdata(_dev);
	struct sa1100_irda *si;

	if (!dev)
		return 0;

	si = dev->priv;
	if (si->open) {
		/*
		 * Stop the transmit queue
		 */
		netif_device_detach(dev);
		disable_irq(dev->irq);
		sa1100_irda_shutdown(si);
		__sa1100_irda_set_power(si, 0);
	}

	return 0;
}

/*
 * Resume the IrDA interface.
 */
static int sa1100_irda_resume(struct device *_dev)
{
	struct net_device *dev = dev_get_drvdata(_dev);
	struct sa1100_irda *si;

	if (!dev)
		return 0;

	si = dev->priv;
	if (si->open) {
		/*
		 * If we missed a speed change, initialise at the new speed
		 * directly.  It is debatable whether this is actually
		 * required, but in the interests of continuing from where
		 * we left off it is desireable.  The converse argument is
		 * that we should re-negotiate at 9600 baud again.
		 */
		if (si->newspeed) {
			si->speed = si->newspeed;
			si->newspeed = 0;
		}

		sa1100_irda_startup(si);
		__sa1100_irda_set_power(si, si->power);
		enable_irq(dev->irq);

		/*
		 * This automatically wakes up the queue
		 */
		netif_device_attach(dev);
	}

	return 0;
}
#else
#define sa1100_irda_suspend	NULL
#define sa1100_irda_resume	NULL
#endif

/*
 * HP-SIR format interrupt service routines.
 */
static void sa1100_irda_hpsir_irq(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;
	int status;

	status = Ser2UTSR0;

	/*
	 * Deal with any receive errors first.  The bytes in error may be
	 * the only bytes in the receive FIFO, so we do this first.
	 */
	while (status & UTSR0_EIF) {
		int stat, data;

		stat = Ser2UTSR1;
		data = Ser2UTDR;

		if (stat & (UTSR1_FRE | UTSR1_ROR)) {
			si->stats.rx_errors++;
			if (stat & UTSR1_FRE)
				si->stats.rx_frame_errors++;
			if (stat & UTSR1_ROR)
				si->stats.rx_fifo_errors++;
		} else
			async_unwrap_char(dev, &si->stats, &si->rx_buff, data);

		status = Ser2UTSR0;
	}

	/*
	 * We must clear certain bits.
	 */
	Ser2UTSR0 = status & (UTSR0_RID | UTSR0_RBB | UTSR0_REB);

	if (status & UTSR0_RFS) {
		/*
		 * There are at least 4 bytes in the FIFO.  Read 3 bytes
		 * and leave the rest to the block below.
		 */
		async_unwrap_char(dev, &si->stats, &si->rx_buff, Ser2UTDR);
		async_unwrap_char(dev, &si->stats, &si->rx_buff, Ser2UTDR);
		async_unwrap_char(dev, &si->stats, &si->rx_buff, Ser2UTDR);
	}

	if (status & (UTSR0_RFS | UTSR0_RID)) {
		/*
		 * Fifo contains more than 1 character.
		 */
		do {
			async_unwrap_char(dev, &si->stats, &si->rx_buff,
					  Ser2UTDR);
		} while (Ser2UTSR1 & UTSR1_RNE);

		dev->last_rx = jiffies;
	}

	if (status & UTSR0_TFS && si->tx_buff.len) {
		/*
		 * Transmitter FIFO is not full
		 */
		do {
			Ser2UTDR = *si->tx_buff.data++;
			si->tx_buff.len -= 1;
		} while (Ser2UTSR1 & UTSR1_TNF && si->tx_buff.len);

		if (si->tx_buff.len == 0) {
			si->stats.tx_packets++;
			si->stats.tx_bytes += si->tx_buff.data -
					      si->tx_buff.head;

			/*
			 * We need to ensure that the transmitter has
			 * finished.
			 */
			do
				rmb();
			while (Ser2UTSR1 & UTSR1_TBY);

			/*
			 * Ok, we've finished transmitting.  Now enable
			 * the receiver.  Sometimes we get a receive IRQ
			 * immediately after a transmit...
			 */
			Ser2UTSR0 = UTSR0_REB | UTSR0_RBB | UTSR0_RID;
			Ser2UTCR3 = UTCR3_RIE | UTCR3_RXE | UTCR3_TXE;

			if (si->newspeed) {
				sa1100_irda_set_speed(si, si->newspeed);
				si->newspeed = 0;
			}

			/* I'm hungry! */
			netif_wake_queue(dev);
		}
	}
}

static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev)
{
	struct sk_buff *skb = si->rxskb;
	dma_addr_t dma_addr;
	unsigned int len, stat, data;

	if (!skb) {
		printk(KERN_ERR "sa1100_ir: SKB is NULL!\n");
		return;
	}

	/*
	 * Get the current data position.
	 */
	dma_addr = sa1100_get_dma_pos(si->rxdma);
	len = dma_addr - si->rxbuf_dma;
	if (len > HPSIR_MAX_RXLEN)
		len = HPSIR_MAX_RXLEN;
	dma_unmap_single(si->dev, si->rxbuf_dma, len, DMA_FROM_DEVICE);

	do {
		/*
		 * Read Status, and then Data.
		 */
		stat = Ser2HSSR1;
		rmb();
		data = Ser2HSDR;

		if (stat & (HSSR1_CRE | HSSR1_ROR)) {
			si->stats.rx_errors++;
			if (stat & HSSR1_CRE)
				si->stats.rx_crc_errors++;
			if (stat & HSSR1_ROR)
				si->stats.rx_frame_errors++;
		} else
			skb->data[len++] = data;

		/*
		 * If we hit the end of frame, there's
		 * no point in continuing.
		 */
		if (stat & HSSR1_EOF)
			break;
	} while (Ser2HSSR0 & HSSR0_EIF);

	if (stat & HSSR1_EOF) {
		si->rxskb = NULL;

		skb_put(skb, len);
		skb->dev = dev;
		skb->mac.raw = skb->data;
		skb->protocol = htons(ETH_P_IRDA);
		si->stats.rx_packets++;
		si->stats.rx_bytes += len;

		/*
		 * Before we pass the buffer up, allocate a new one.
		 */
		sa1100_irda_rx_alloc(si);

		netif_rx(skb);
		dev->last_rx = jiffies;
	} else {
		/*
		 * Remap the buffer.
		 */
		si->rxbuf_dma = dma_map_single(si->dev, si->rxskb->data,
						HPSIR_MAX_RXLEN,
						DMA_FROM_DEVICE);
	}
}

/*
 * FIR format interrupt service routine.  We only have to
 * handle RX events; transmit events go via the TX DMA handler.
 *
 * No matter what, we disable RX, process, and the restart RX.
 */
static void sa1100_irda_fir_irq(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;

	/*
	 * Stop RX DMA
	 */
	sa1100_stop_dma(si->rxdma);

	/*
	 * Framing error - we throw away the packet completely.
	 * Clearing RXE flushes the error conditions and data
	 * from the fifo.
	 */
	if (Ser2HSSR0 & (HSSR0_FRE | HSSR0_RAB)) {
		si->stats.rx_errors++;

		if (Ser2HSSR0 & HSSR0_FRE)
			si->stats.rx_frame_errors++;

		/*
		 * Clear out the DMA...
		 */
		Ser2HSCR0 = si->hscr0 | HSCR0_HSSP;

		/*
		 * Clear selected status bits now, so we
		 * don't miss them next time around.
		 */
		Ser2HSSR0 = HSSR0_FRE | HSSR0_RAB;
	}

	/*
	 * Deal with any receive errors.  The any of the lowest
	 * 8 bytes in the FIFO may contain an error.  We must read
	 * them one by one.  The "error" could even be the end of
	 * packet!
	 */
	if (Ser2HSSR0 & HSSR0_EIF)
		sa1100_irda_fir_error(si, dev);

	/*
	 * No matter what happens, we must restart reception.
	 */
	sa1100_irda_rx_dma_start(si);
}

static irqreturn_t sa1100_irda_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = dev_id;
	if (IS_FIR(((struct sa1100_irda *)dev->priv)))
		sa1100_irda_fir_irq(dev);
	else
		sa1100_irda_hpsir_irq(dev);
	return IRQ_HANDLED;
}

/*
 * TX DMA completion handler.
 */
static void sa1100_irda_txdma_irq(void *id)
{
	struct net_device *dev = id;
	struct sa1100_irda *si = dev->priv;
	struct sk_buff *skb = si->txskb;

	si->txskb = NULL;

	/*
	 * Wait for the transmission to complete.  Unfortunately,
	 * the hardware doesn't give us an interrupt to indicate
	 * "end of frame".
	 */
	do
		rmb();
	while (!(Ser2HSSR0 & HSSR0_TUR) || Ser2HSSR1 & HSSR1_TBY);

	/*
	 * Clear the transmit underrun bit.
	 */
	Ser2HSSR0 = HSSR0_TUR;

	/*
	 * Do we need to change speed?  Note that we're lazy
	 * here - we don't free the old rxskb.  We don't need
	 * to allocate a buffer either.
	 */
	if (si->newspeed) {
		sa1100_irda_set_speed(si, si->newspeed);
		si->newspeed = 0;
	}

	/*
	 * Start reception.  This disables the transmitter for
	 * us.  This will be using the existing RX buffer.
	 */
	sa1100_irda_rx_dma_start(si);

	/*
	 * Account and free the packet.
	 */
	if (skb) {
		dma_unmap_single(si->dev, si->txbuf_dma, skb->len, DMA_TO_DEVICE);
		si->stats.tx_packets ++;
		si->stats.tx_bytes += skb->len;
		dev_kfree_skb_irq(skb);
	}

	/*
	 * Make sure that the TX queue is available for sending
	 * (for retries).  TX has priority over RX at all times.
	 */
	netif_wake_queue(dev);
}

static int sa1100_irda_hard_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;
	int speed = irda_get_next_speed(skb);

	/*
	 * Does this packet contain a request to change the interface
	 * speed?  If so, remember it until we complete the transmission
	 * of this frame.
	 */
	if (speed != si->speed && speed != -1)
		si->newspeed = speed;

	/*
	 * If this is an empty frame, we can bypass a lot.
	 */
	if (skb->len == 0) {
		if (si->newspeed) {
			si->newspeed = 0;
			sa1100_irda_set_speed(si, speed);
		}
		dev_kfree_skb(skb);
		return 0;
	}

	if (!IS_FIR(si)) {
		netif_stop_queue(dev);

		si->tx_buff.data = si->tx_buff.head;
		si->tx_buff.len  = async_wrap_skb(skb, si->tx_buff.data,
						  si->tx_buff.truesize);

		/*
		 * Set the transmit interrupt enable.  This will fire
		 * off an interrupt immediately.  Note that we disable
		 * the receiver so we won't get spurious characteres
		 * received.
		 */
		Ser2UTCR3 = UTCR3_TIE | UTCR3_TXE;

		dev_kfree_skb(skb);
	} else {
		int mtt = irda_get_mtt(skb);

		/*
		 * We must not be transmitting...
		 */
		if (si->txskb)
			BUG();

		netif_stop_queue(dev);

		si->txskb = skb;
		si->txbuf_dma = dma_map_single(si->dev, skb->data,
					 skb->len, DMA_TO_DEVICE);

		sa1100_start_dma(si->txdma, si->txbuf_dma, skb->len);

		/*
		 * If we have a mean turn-around time, impose the specified
		 * specified delay.  We could shorten this by timing from
		 * the point we received the packet.
		 */
		if (mtt)
			udelay(mtt);

		Ser2HSCR0 = si->hscr0 | HSCR0_HSSP | HSCR0_TXE;
	}

	dev->trans_start = jiffies;

	return 0;
}

static int
sa1100_irda_ioctl(struct net_device *dev, struct ifreq *ifreq, int cmd)
{
	struct if_irda_req *rq = (struct if_irda_req *)ifreq;
	struct sa1100_irda *si = dev->priv;
	int ret = -EOPNOTSUPP;

	switch (cmd) {
	case SIOCSBANDWIDTH:
		if (capable(CAP_NET_ADMIN)) {
			/*
			 * We are unable to set the speed if the
			 * device is not running.
			 */
			if (si->open) {
				ret = sa1100_irda_set_speed(si,
						rq->ifr_baudrate);
			} else {
				printk("sa1100_irda_ioctl: SIOCSBANDWIDTH: !netif_running\n");
				ret = 0;
			}
		}
		break;

	case SIOCSMEDIABUSY:
		ret = -EPERM;
		if (capable(CAP_NET_ADMIN)) {
			irda_device_set_media_busy(dev, TRUE);
			ret = 0;
		}
		break;

	case SIOCGRECEIVING:
		rq->ifr_receiving = IS_FIR(si) ? 0
					: si->rx_buff.state != OUTSIDE_FRAME;
		break;

	default:
		break;
	}
		
	return ret;
}

static struct net_device_stats *sa1100_irda_stats(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;
	return &si->stats;
}

static int sa1100_irda_start(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;
	int err;

	si->speed = 9600;

	err = request_irq(dev->irq, sa1100_irda_irq, 0, dev->name, dev);
	if (err)
		goto err_irq;

	err = sa1100_request_dma(DMA_Ser2HSSPRd, "IrDA receive",
				 NULL, NULL, &si->rxdma);
	if (err)
		goto err_rx_dma;

	err = sa1100_request_dma(DMA_Ser2HSSPWr, "IrDA transmit",
				 sa1100_irda_txdma_irq, dev, &si->txdma);
	if (err)
		goto err_tx_dma;

	/*
	 * The interrupt must remain disabled for now.
	 */
	disable_irq(dev->irq);

	/*
	 * Setup the serial port for the specified speed.
	 */
	err = sa1100_irda_startup(si);
	if (err)
		goto err_startup;

	/*
	 * Open a new IrLAP layer instance.
	 */
	si->irlap = irlap_open(dev, &si->qos, "sa1100");
	err = -ENOMEM;
	if (!si->irlap)
		goto err_irlap;

	/*
	 * Now enable the interrupt and start the queue
	 */
	si->open = 1;
	sa1100_set_power(si, power_level); /* low power mode */
	enable_irq(dev->irq);
	netif_start_queue(dev);
	return 0;

err_irlap:
	si->open = 0;
	sa1100_irda_shutdown(si);
err_startup:
	sa1100_free_dma(si->txdma);
err_tx_dma:
	sa1100_free_dma(si->rxdma);
err_rx_dma:
	free_irq(dev->irq, dev);
err_irq:
	return err;
}

static int sa1100_irda_stop(struct net_device *dev)
{
	struct sa1100_irda *si = dev->priv;

	disable_irq(dev->irq);
	sa1100_irda_shutdown(si);

	/*
	 * If we have been doing DMA receive, make sure we
	 * tidy that up cleanly.
	 */
	if (si->rxskb) {
		dma_unmap_single(si->dev, si->rxbuf_dma, HPSIR_MAX_RXLEN,
				 DMA_FROM_DEVICE);
		dev_kfree_skb(si->rxskb);
		si->rxskb = NULL;
	}

	/* Stop IrLAP */
	if (si->irlap) {
		irlap_close(si->irlap);
		si->irlap = NULL;
	}

	netif_stop_queue(dev);
	si->open = 0;

	/*
	 * Free resources
	 */
	sa1100_free_dma(si->txdma);
	sa1100_free_dma(si->rxdma);
	free_irq(dev->irq, dev);

	sa1100_set_power(si, 0);

	return 0;
}

static int sa1100_irda_init_iobuf(iobuff_t *io, int size)
{
	io->head = kmalloc(size, GFP_KERNEL | GFP_DMA);
	if (io->head != NULL) {
		io->truesize = size;
		io->in_frame = FALSE;
		io->state    = OUTSIDE_FRAME;
		io->data     = io->head;
	}
	return io->head ? 0 : -ENOMEM;
}

static int sa1100_irda_probe(struct device *_dev)
{
	struct platform_device *pdev = to_platform_device(_dev);
	struct net_device *dev;
	struct sa1100_irda *si;
	unsigned int baudrate_mask;
	int err;

	if (!pdev->dev.platform_data)
		return -EINVAL;

	err = request_mem_region(__PREG(Ser2UTCR0), 0x24, "IrDA") ? 0 : -EBUSY;
	if (err)
		goto err_mem_1;
	err = request_mem_region(__PREG(Ser2HSCR0), 0x1c, "IrDA") ? 0 : -EBUSY;
	if (err)
		goto err_mem_2;
	err = request_mem_region(__PREG(Ser2HSCR2), 0x04, "IrDA") ? 0 : -EBUSY;
	if (err)
		goto err_mem_3;

	dev = alloc_irdadev(sizeof(struct sa1100_irda));
	if (!dev)
		goto err_mem_4;

	si = dev->priv;
	si->dev = &pdev->dev;
	si->pdata = pdev->dev.platform_data;

	/*
	 * Initialise the HP-SIR buffers
	 */
	err = sa1100_irda_init_iobuf(&si->rx_buff, 14384);
	if (err)
		goto err_mem_5;
	err = sa1100_irda_init_iobuf(&si->tx_buff, 4000);
	if (err)
		goto err_mem_5;

	dev->hard_start_xmit	= sa1100_irda_hard_xmit;
	dev->open		= sa1100_irda_start;
	dev->stop		= sa1100_irda_stop;
	dev->do_ioctl		= sa1100_irda_ioctl;
	dev->get_stats		= sa1100_irda_stats;
	dev->irq		= IRQ_Ser2ICP;

	irda_init_max_qos_capabilies(&si->qos);

	/*
	 * We support original IRDA up to 115k2. (we don't currently
	 * support 4Mbps).  Min Turn Time set to 1ms or greater.
	 */
	baudrate_mask = IR_9600;

	switch (max_rate) {
	case 4000000:		baudrate_mask |= IR_4000000 << 8;
	case 115200:		baudrate_mask |= IR_115200;
	case 57600:		baudrate_mask |= IR_57600;
	case 38400:		baudrate_mask |= IR_38400;
	case 19200:		baudrate_mask |= IR_19200;
	}
		
	si->qos.baud_rate.bits &= baudrate_mask;
	si->qos.min_turn_time.bits = 7;

	irda_qos_bits_to_value(&si->qos);

	si->utcr4 = UTCR4_HPSIR;
	if (tx_lpm)
		si->utcr4 |= UTCR4_Z1_6us;

	/*
	 * Initially enable HP-SIR modulation, and ensure that the port
	 * is disabled.
	 */
	Ser2UTCR3 = 0;
	Ser2UTCR4 = si->utcr4;
	Ser2HSCR0 = HSCR0_UART;

	err = register_netdev(dev);
	if (err == 0)
		dev_set_drvdata(&pdev->dev, dev);

	if (err) {
 err_mem_5:
		kfree(si->tx_buff.head);
		kfree(si->rx_buff.head);
		free_netdev(dev);
 err_mem_4:
		release_mem_region(__PREG(Ser2HSCR2), 0x04);
 err_mem_3:
		release_mem_region(__PREG(Ser2HSCR0), 0x1c);
 err_mem_2:
		release_mem_region(__PREG(Ser2UTCR0), 0x24);
	}
 err_mem_1:
	return err;
}

static int sa1100_irda_remove(struct device *_dev)
{
	struct net_device *dev = dev_get_drvdata(_dev);

	if (dev) {
		struct sa1100_irda *si = dev->priv;
		unregister_netdev(dev);
		kfree(si->tx_buff.head);
		kfree(si->rx_buff.head);
		free_netdev(dev);
	}

	release_mem_region(__PREG(Ser2HSCR2), 0x04);
	release_mem_region(__PREG(Ser2HSCR0), 0x1c);
	release_mem_region(__PREG(Ser2UTCR0), 0x24);

	return 0;
}

static struct device_driver sa1100ir_driver = {
	.name		= "sa11x0-ir",
	.bus		= &platform_bus_type,
	.probe		= sa1100_irda_probe,
	.remove		= sa1100_irda_remove,
	.suspend	= sa1100_irda_suspend,
	.resume		= sa1100_irda_resume,
};

static int __init sa1100_irda_init(void)
{
	/*
	 * Limit power level a sensible range.
	 */
	if (power_level < 1)
		power_level = 1;
	if (power_level > 3)
		power_level = 3;

	return driver_register(&sa1100ir_driver);
}

static void __exit sa1100_irda_exit(void)
{
	driver_unregister(&sa1100ir_driver);
}

module_init(sa1100_irda_init);
module_exit(sa1100_irda_exit);
module_param(power_level, int, 0);
module_param(tx_lpm, int, 0);
module_param(max_rate, int, 0);

MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("StrongARM SA1100 IrDA driver");
MODULE_LICENSE("GPL");
MODULE_PARM_DESC(power_level, "IrDA power level, 1 (low) to 3 (high)");
MODULE_PARM_DESC(tx_lpm, "Enable transmitter low power (1.6us) mode");
MODULE_PARM_DESC(max_rate, "Maximum baud rate (4000000, 115200, 57600, 38400, 19200, 9600)");