aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/irda/sh_sir.c
blob: 24aefcd840654aa10ca97cee1f7b323d9d7a404e (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
/*
 * SuperH IrDA Driver
 *
 * Copyright (C) 2009 Renesas Solutions Corp.
 * Kuninori Morimoto <morimoto.kuninori@renesas.com>
 *
 * Based on bfin_sir.c
 * Copyright 2006-2009 Analog Devices Inc.
 *
 * 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.
 */

#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <net/irda/wrapper.h>
#include <net/irda/irda_device.h>
#include <asm/clock.h>

#define DRIVER_NAME "sh_sir"

#define RX_PHASE	(1 << 0)
#define TX_PHASE	(1 << 1)
#define TX_COMP_PHASE	(1 << 2) /* tx complete */
#define NONE_PHASE	(1 << 31)

#define IRIF_RINTCLR	0x0016 /* DMA rx interrupt source clear */
#define IRIF_TINTCLR	0x0018 /* DMA tx interrupt source clear */
#define IRIF_SIR0	0x0020 /* IrDA-SIR10 control */
#define IRIF_SIR1	0x0022 /* IrDA-SIR10 baudrate error correction */
#define IRIF_SIR2	0x0024 /* IrDA-SIR10 baudrate count */
#define IRIF_SIR3	0x0026 /* IrDA-SIR10 status */
#define IRIF_SIR_FRM	0x0028 /* Hardware frame processing set */
#define IRIF_SIR_EOF	0x002A /* EOF value */
#define IRIF_SIR_FLG	0x002C /* Flag clear */
#define IRIF_UART_STS2	0x002E /* UART status 2 */
#define IRIF_UART0	0x0030 /* UART control */
#define IRIF_UART1	0x0032 /* UART status */
#define IRIF_UART2	0x0034 /* UART mode */
#define IRIF_UART3	0x0036 /* UART transmit data */
#define IRIF_UART4	0x0038 /* UART receive data */
#define IRIF_UART5	0x003A /* UART interrupt mask */
#define IRIF_UART6	0x003C /* UART baud rate error correction */
#define IRIF_UART7	0x003E /* UART baud rate count set */
#define IRIF_CRC0	0x0040 /* CRC engine control */
#define IRIF_CRC1	0x0042 /* CRC engine input data */
#define IRIF_CRC2	0x0044 /* CRC engine calculation */
#define IRIF_CRC3	0x0046 /* CRC engine output data 1 */
#define IRIF_CRC4	0x0048 /* CRC engine output data 2 */

/* IRIF_SIR0 */
#define IRTPW		(1 << 1) /* transmit pulse width select */
#define IRERRC		(1 << 0) /* Clear receive pulse width error */

/* IRIF_SIR3 */
#define IRERR		(1 << 0) /* received pulse width Error */

/* IRIF_SIR_FRM */
#define EOFD		(1 << 9) /* EOF detection flag */
#define FRER		(1 << 8) /* Frame Error bit */
#define FRP		(1 << 0) /* Frame processing set */

/* IRIF_UART_STS2 */
#define IRSME		(1 << 6) /* Receive Sum     Error flag */
#define IROVE		(1 << 5) /* Receive Overrun Error flag */
#define IRFRE		(1 << 4) /* Receive Framing Error flag */
#define IRPRE		(1 << 3) /* Receive Parity  Error flag */

/* IRIF_UART0_*/
#define TBEC		(1 << 2) /* Transmit Data Clear */
#define RIE		(1 << 1) /* Receive Enable */
#define TIE		(1 << 0) /* Transmit Enable */

/* IRIF_UART1 */
#define URSME		(1 << 6) /* Receive Sum Error Flag */
#define UROVE		(1 << 5) /* Receive Overrun Error Flag */
#define URFRE		(1 << 4) /* Receive Framing Error Flag */
#define URPRE		(1 << 3) /* Receive Parity Error Flag */
#define RBF		(1 << 2) /* Receive Buffer Full Flag */
#define TSBE		(1 << 1) /* Transmit Shift Buffer Empty Flag */
#define TBE		(1 << 0) /* Transmit Buffer Empty flag */
#define TBCOMP		(TSBE | TBE)

/* IRIF_UART5 */
#define RSEIM		(1 << 6) /* Receive Sum Error Flag IRQ Mask */
#define RBFIM		(1 << 2) /* Receive Buffer Full Flag IRQ Mask */
#define TSBEIM		(1 << 1) /* Transmit Shift Buffer Empty Flag IRQ Mask */
#define TBEIM		(1 << 0) /* Transmit Buffer Empty Flag IRQ Mask */
#define RX_MASK		(RSEIM  | RBFIM)

/* IRIF_CRC0 */
#define CRC_RST		(1 << 15) /* CRC Engine Reset */
#define CRC_CT_MASK	0x0FFF

/************************************************************************


			structure


************************************************************************/
struct sh_sir_self {
	void __iomem		*membase;
	unsigned int		 irq;
	struct clk		*clk;

	struct net_device	*ndev;

	struct irlap_cb		*irlap;
	struct qos_info		qos;

	iobuff_t		tx_buff;
	iobuff_t		rx_buff;
};

/************************************************************************


			common function


************************************************************************/
static void sh_sir_write(struct sh_sir_self *self, u32 offset, u16 data)
{
	iowrite16(data, self->membase + offset);
}

static u16 sh_sir_read(struct sh_sir_self *self, u32 offset)
{
	return ioread16(self->membase + offset);
}

static void sh_sir_update_bits(struct sh_sir_self *self, u32 offset,
			       u16 mask, u16 data)
{
	u16 old, new;

	old = sh_sir_read(self, offset);
	new = (old & ~mask) | data;
	if (old != new)
		sh_sir_write(self, offset, new);
}

/************************************************************************


			CRC function


************************************************************************/
static void sh_sir_crc_reset(struct sh_sir_self *self)
{
	sh_sir_write(self, IRIF_CRC0, CRC_RST);
}

static void sh_sir_crc_add(struct sh_sir_self *self, u8 data)
{
	sh_sir_write(self, IRIF_CRC1, (u16)data);
}

static u16 sh_sir_crc_cnt(struct sh_sir_self *self)
{
	return CRC_CT_MASK & sh_sir_read(self, IRIF_CRC0);
}

static u16 sh_sir_crc_out(struct sh_sir_self *self)
{
	return sh_sir_read(self, IRIF_CRC4);
}

static int sh_sir_crc_init(struct sh_sir_self *self)
{
	struct device *dev = &self->ndev->dev;
	int ret = -EIO;
	u16 val;

	sh_sir_crc_reset(self);

	sh_sir_crc_add(self, 0xCC);
	sh_sir_crc_add(self, 0xF5);
	sh_sir_crc_add(self, 0xF1);
	sh_sir_crc_add(self, 0xA7);

	val = sh_sir_crc_cnt(self);
	if (4 != val) {
		dev_err(dev, "CRC count error %x\n", val);
		goto crc_init_out;
	}

	val = sh_sir_crc_out(self);
	if (0x51DF != val) {
		dev_err(dev, "CRC result error%x\n", val);
		goto crc_init_out;
	}

	ret = 0;

crc_init_out:

	sh_sir_crc_reset(self);
	return ret;
}

/************************************************************************


			baud rate functions


************************************************************************/
#define SCLK_BASE 1843200 /* 1.8432MHz */

static u32 sh_sir_find_sclk(struct clk *irda_clk)
{
	struct cpufreq_frequency_table *freq_table = irda_clk->freq_table;
	struct clk *pclk = clk_get(NULL, "peripheral_clk");
	u32 limit, min = 0xffffffff, tmp;
	int i, index = 0;

	limit = clk_get_rate(pclk);
	clk_put(pclk);

	/* IrDA can not set over peripheral_clk */
	for (i = 0;
	     freq_table[i].frequency != CPUFREQ_TABLE_END;
	     i++) {
		u32 freq = freq_table[i].frequency;

		if (freq == CPUFREQ_ENTRY_INVALID)
			continue;

		/* IrDA should not over peripheral_clk */
		if (freq > limit)
			continue;

		tmp = freq % SCLK_BASE;
		if (tmp < min) {
			min = tmp;
			index = i;
		}
	}

	return freq_table[index].frequency;
}

#define ERR_ROUNDING(a) ((a + 5000) / 10000)
static int sh_sir_set_baudrate(struct sh_sir_self *self, u32 baudrate)
{
	struct clk *clk;
	struct device *dev = &self->ndev->dev;
	u32 rate;
	u16 uabca, uabc;
	u16 irbca, irbc;
	u32 min, rerr, tmp;
	int i;

	/* Baud Rate Error Correction x 10000 */
	u32 rate_err_array[] = {
		   0,  625, 1250, 1875,
		2500, 3125, 3750, 4375,
		5000, 5625, 6250, 6875,
		7500, 8125, 8750, 9375,
	};

	/*
	 * FIXME
	 *
	 * it support 9600 only now
	 */
	switch (baudrate) {
	case 9600:
		break;
	default:
		dev_err(dev, "un-supported baudrate %d\n", baudrate);
		return -EIO;
	}

	clk = clk_get(NULL, "irda_clk");
	if (IS_ERR(clk)) {
		dev_err(dev, "can not get irda_clk\n");
		return -EIO;
	}

	clk_set_rate(clk, sh_sir_find_sclk(clk));
	rate = clk_get_rate(clk);
	clk_put(clk);

	dev_dbg(dev, "selected sclk = %d\n", rate);

	/*
	 * CALCULATION
	 *
	 * 1843200 = system rate / (irbca + (irbc + 1))
	 */

	irbc = rate / SCLK_BASE;

	tmp = rate - (SCLK_BASE * irbc);
	tmp *= 10000;

	rerr = tmp / SCLK_BASE;

	min = 0xffffffff;
	irbca = 0;
	for (i = 0; i < ARRAY_SIZE(rate_err_array); i++) {
		tmp = abs(rate_err_array[i] - rerr);
		if (min > tmp) {
			min = tmp;
			irbca = i;
		}
	}

	tmp = rate / (irbc + ERR_ROUNDING(rate_err_array[irbca]));
	if ((SCLK_BASE / 100) < abs(tmp - SCLK_BASE))
		dev_warn(dev, "IrDA freq error margin over %d\n", tmp);

	dev_dbg(dev, "target = %d, result = %d, infrared = %d.%d\n",
	       SCLK_BASE, tmp, irbc, rate_err_array[irbca]);

	irbca = (irbca & 0xF) << 4;
	irbc  = (irbc - 1) & 0xF;

	if (!irbc) {
		dev_err(dev, "sh_sir can not set 0 in IRIF_SIR2\n");
		return -EIO;
	}

	sh_sir_write(self, IRIF_SIR0, IRTPW | IRERRC);
	sh_sir_write(self, IRIF_SIR1, irbca);
	sh_sir_write(self, IRIF_SIR2, irbc);

	/*
	 * CALCULATION
	 *
	 * BaudRate[bps] = system rate / (uabca + (uabc + 1) x 16)
	 */

	uabc = rate / baudrate;
	uabc = (uabc / 16) - 1;
	uabc = (uabc + 1) * 16;

	tmp = rate - (uabc * baudrate);
	tmp *= 10000;

	rerr = tmp / baudrate;

	min = 0xffffffff;
	uabca = 0;
	for (i = 0; i < ARRAY_SIZE(rate_err_array); i++) {
		tmp = abs(rate_err_array[i] - rerr);
		if (min > tmp) {
			min = tmp;
			uabca = i;
		}
	}

	tmp = rate / (uabc + ERR_ROUNDING(rate_err_array[uabca]));
	if ((baudrate / 100) < abs(tmp - baudrate))
		dev_warn(dev, "UART freq error margin over %d\n", tmp);

	dev_dbg(dev, "target = %d, result = %d, uart = %d.%d\n",
	       baudrate, tmp,
	       uabc, rate_err_array[uabca]);

	uabca = (uabca & 0xF) << 4;
	uabc  = (uabc / 16) - 1;

	sh_sir_write(self, IRIF_UART6, uabca);
	sh_sir_write(self, IRIF_UART7, uabc);

	return 0;
}

/************************************************************************


			iobuf function


************************************************************************/
static int __sh_sir_init_iobuf(iobuff_t *io, int size)
{
	io->head = kmalloc(size, GFP_KERNEL);
	if (!io->head)
		return -ENOMEM;

	io->truesize	= size;
	io->in_frame	= FALSE;
	io->state	= OUTSIDE_FRAME;
	io->data	= io->head;

	return 0;
}

static void sh_sir_remove_iobuf(struct sh_sir_self *self)
{
	kfree(self->rx_buff.head);
	kfree(self->tx_buff.head);

	self->rx_buff.head = NULL;
	self->tx_buff.head = NULL;
}

static int sh_sir_init_iobuf(struct sh_sir_self *self, int rxsize, int txsize)
{
	int err = -ENOMEM;

	if (self->rx_buff.head ||
	    self->tx_buff.head) {
		dev_err(&self->ndev->dev, "iobuff has already existed.");
		return err;
	}

	err = __sh_sir_init_iobuf(&self->rx_buff, rxsize);
	if (err)
		goto iobuf_err;

	err = __sh_sir_init_iobuf(&self->tx_buff, txsize);

iobuf_err:
	if (err)
		sh_sir_remove_iobuf(self);

	return err;
}

/************************************************************************


			status function


************************************************************************/
static void sh_sir_clear_all_err(struct sh_sir_self *self)
{
	/* Clear error flag for receive pulse width */
	sh_sir_update_bits(self, IRIF_SIR0, IRERRC, IRERRC);

	/* Clear frame / EOF error flag */
	sh_sir_write(self, IRIF_SIR_FLG, 0xffff);

	/* Clear all status error */
	sh_sir_write(self, IRIF_UART_STS2, 0);
}

static void sh_sir_set_phase(struct sh_sir_self *self, int phase)
{
	u16 uart5 = 0;
	u16 uart0 = 0;

	switch (phase) {
	case TX_PHASE:
		uart5 = TBEIM;
		uart0 = TBEC | TIE;
		break;
	case TX_COMP_PHASE:
		uart5 = TSBEIM;
		uart0 = TIE;
		break;
	case RX_PHASE:
		uart5 = RX_MASK;
		uart0 = RIE;
		break;
	default:
		break;
	}

	sh_sir_write(self, IRIF_UART5, uart5);
	sh_sir_write(self, IRIF_UART0, uart0);
}

static int sh_sir_is_which_phase(struct sh_sir_self *self)
{
	u16 val = sh_sir_read(self, IRIF_UART5);

	if (val & TBEIM)
		return TX_PHASE;

	if (val & TSBEIM)
		return TX_COMP_PHASE;

	if (val & RX_MASK)
		return RX_PHASE;

	return NONE_PHASE;
}

static void sh_sir_tx(struct sh_sir_self *self, int phase)
{
	switch (phase) {
	case TX_PHASE:
		if (0 >= self->tx_buff.len) {
			sh_sir_set_phase(self, TX_COMP_PHASE);
		} else {
			sh_sir_write(self, IRIF_UART3, self->tx_buff.data[0]);
			self->tx_buff.len--;
			self->tx_buff.data++;
		}
		break;
	case TX_COMP_PHASE:
		sh_sir_set_phase(self, RX_PHASE);
		netif_wake_queue(self->ndev);
		break;
	default:
		dev_err(&self->ndev->dev, "should not happen\n");
		break;
	}
}

static int sh_sir_read_data(struct sh_sir_self *self)
{
	u16 val = 0;
	int timeout = 1024;

	while (timeout--) {
		val = sh_sir_read(self, IRIF_UART1);

		/* data get */
		if (val & RBF) {
			if (val & (URSME | UROVE | URFRE | URPRE))
				break;

			return (int)sh_sir_read(self, IRIF_UART4);
		}

		udelay(1);
	}

	dev_err(&self->ndev->dev, "UART1 %04x : STATUS %04x\n",
		val, sh_sir_read(self, IRIF_UART_STS2));

	/* read data register for clear error */
	sh_sir_read(self, IRIF_UART4);

	return -1;
}

static void sh_sir_rx(struct sh_sir_self *self)
{
	int timeout = 1024;
	int data;

	while (timeout--) {
		data = sh_sir_read_data(self);
		if (data < 0)
			break;

		async_unwrap_char(self->ndev, &self->ndev->stats,
				  &self->rx_buff, (u8)data);
		self->ndev->last_rx = jiffies;

		if (EOFD & sh_sir_read(self, IRIF_SIR_FRM))
			continue;

		break;
	}
}

static irqreturn_t sh_sir_irq(int irq, void *dev_id)
{
	struct sh_sir_self *self = dev_id;
	struct device *dev = &self->ndev->dev;
	int phase = sh_sir_is_which_phase(self);

	switch (phase) {
	case TX_COMP_PHASE:
	case TX_PHASE:
		sh_sir_tx(self, phase);
		break;
	case RX_PHASE:
		if (sh_sir_read(self, IRIF_SIR3))
			dev_err(dev, "rcv pulse width error occurred\n");

		sh_sir_rx(self);
		sh_sir_clear_all_err(self);
		break;
	default:
		dev_err(dev, "unknown interrupt\n");
	}

	 return IRQ_HANDLED;
}

/************************************************************************


			net_device_ops function


************************************************************************/
static int sh_sir_hard_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	struct sh_sir_self *self = netdev_priv(ndev);
	int speed = irda_get_next_speed(skb);

	if ((0 < speed) &&
	    (9600 != speed)) {
		dev_err(&ndev->dev, "support 9600 only (%d)\n", speed);
		return -EIO;
	}

	netif_stop_queue(ndev);

	self->tx_buff.data = self->tx_buff.head;
	self->tx_buff.len = 0;
	if (skb->len)
		self->tx_buff.len = async_wrap_skb(skb, self->tx_buff.data,
						   self->tx_buff.truesize);

	sh_sir_set_phase(self, TX_PHASE);
	dev_kfree_skb(skb);

	return 0;
}

static int sh_sir_ioctl(struct net_device *ndev, struct ifreq *ifreq, int cmd)
{
	/*
	 * FIXME
	 *
	 * This function is needed for irda framework.
	 * But nothing to do now
	 */
	return 0;
}

static struct net_device_stats *sh_sir_stats(struct net_device *ndev)
{
	struct sh_sir_self *self = netdev_priv(ndev);

	return &self->ndev->stats;
}

static int sh_sir_open(struct net_device *ndev)
{
	struct sh_sir_self *self = netdev_priv(ndev);
	int err;

	clk_enable(self->clk);
	err = sh_sir_crc_init(self);
	if (err)
		goto open_err;

	sh_sir_set_baudrate(self, 9600);

	self->irlap = irlap_open(ndev, &self->qos, DRIVER_NAME);
	if (!self->irlap) {
		err = -ENODEV;
		goto open_err;
	}

	/*
	 * Now enable the interrupt then start the queue
	 */
	sh_sir_update_bits(self, IRIF_SIR_FRM, FRP, FRP);
	sh_sir_read(self, IRIF_UART1); /* flag clear */
	sh_sir_read(self, IRIF_UART4); /* flag clear */
	sh_sir_set_phase(self, RX_PHASE);

	netif_start_queue(ndev);

	dev_info(&self->ndev->dev, "opened\n");

	return 0;

open_err:
	clk_disable(self->clk);

	return err;
}

static int sh_sir_stop(struct net_device *ndev)
{
	struct sh_sir_self *self = netdev_priv(ndev);

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

	netif_stop_queue(ndev);

	dev_info(&ndev->dev, "stopped\n");

	return 0;
}

static const struct net_device_ops sh_sir_ndo = {
	.ndo_open		= sh_sir_open,
	.ndo_stop		= sh_sir_stop,
	.ndo_start_xmit		= sh_sir_hard_xmit,
	.ndo_do_ioctl		= sh_sir_ioctl,
	.ndo_get_stats		= sh_sir_stats,
};

/************************************************************************


			platform_driver function


************************************************************************/
static int sh_sir_probe(struct platform_device *pdev)
{
	struct net_device *ndev;
	struct sh_sir_self *self;
	struct resource *res;
	char clk_name[8];
	int irq;
	int err = -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	irq = platform_get_irq(pdev, 0);
	if (!res || irq < 0) {
		dev_err(&pdev->dev, "Not enough platform resources.\n");
		goto exit;
	}

	ndev = alloc_irdadev(sizeof(*self));
	if (!ndev)
		goto exit;

	self = netdev_priv(ndev);
	self->membase = ioremap_nocache(res->start, resource_size(res));
	if (!self->membase) {
		err = -ENXIO;
		dev_err(&pdev->dev, "Unable to ioremap.\n");
		goto err_mem_1;
	}

	err = sh_sir_init_iobuf(self, IRDA_SKB_MAX_MTU, IRDA_SIR_MAX_FRAME);
	if (err)
		goto err_mem_2;

	snprintf(clk_name, sizeof(clk_name), "irda%d", pdev->id);
	self->clk = clk_get(&pdev->dev, clk_name);
	if (IS_ERR(self->clk)) {
		dev_err(&pdev->dev, "cannot get clock \"%s\"\n", clk_name);
		err = -ENODEV;
		goto err_mem_3;
	}

	irda_init_max_qos_capabilies(&self->qos);

	ndev->netdev_ops	= &sh_sir_ndo;
	ndev->irq		= irq;

	self->ndev			= ndev;
	self->qos.baud_rate.bits	&= IR_9600; /* FIXME */
	self->qos.min_turn_time.bits	= 1; /* 10 ms or more */

	irda_qos_bits_to_value(&self->qos);

	err = register_netdev(ndev);
	if (err)
		goto err_mem_4;

	platform_set_drvdata(pdev, ndev);
	err = request_irq(irq, sh_sir_irq, IRQF_DISABLED, "sh_sir", self);
	if (err) {
		dev_warn(&pdev->dev, "Unable to attach sh_sir interrupt\n");
		goto err_mem_4;
	}

	dev_info(&pdev->dev, "SuperH IrDA probed\n");

	goto exit;

err_mem_4:
	clk_put(self->clk);
err_mem_3:
	sh_sir_remove_iobuf(self);
err_mem_2:
	iounmap(self->membase);
err_mem_1:
	free_netdev(ndev);
exit:
	return err;
}

static int sh_sir_remove(struct platform_device *pdev)
{
	struct net_device *ndev = platform_get_drvdata(pdev);
	struct sh_sir_self *self = netdev_priv(ndev);

	if (!self)
		return 0;

	unregister_netdev(ndev);
	clk_put(self->clk);
	sh_sir_remove_iobuf(self);
	iounmap(self->membase);
	free_netdev(ndev);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver sh_sir_driver = {
	.probe   = sh_sir_probe,
	.remove  = sh_sir_remove,
	.driver  = {
		.name = DRIVER_NAME,
	},
};

module_platform_driver(sh_sir_driver);

MODULE_AUTHOR("Kuninori Morimoto <morimoto.kuninori@renesas.com>");
MODULE_DESCRIPTION("SuperH IrDA driver");
MODULE_LICENSE("GPL");