summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/broadcom/b43/phy_common.c
blob: 85f2ca98956567bd28599fbe4d1499e549a1f425 (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
/*

  Broadcom B43 wireless driver
  Common PHY routines

  Copyright (c) 2005 Martin Langer <martin-langer@gmx.de>,
  Copyright (c) 2005-2007 Stefano Brivio <stefano.brivio@polimi.it>
  Copyright (c) 2005-2008 Michael Buesch <m@bues.ch>
  Copyright (c) 2005, 2006 Danny van Dyk <kugelfang@gentoo.org>
  Copyright (c) 2005, 2006 Andreas Jaggi <andreas.jaggi@waterwave.ch>

  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; see the file COPYING.  If not, write to
  the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
  Boston, MA 02110-1301, USA.

*/

#include "phy_common.h"
#include "phy_g.h"
#include "phy_a.h"
#include "phy_n.h"
#include "phy_lp.h"
#include "phy_ht.h"
#include "phy_lcn.h"
#include "phy_ac.h"
#include "b43.h"
#include "main.h"


int b43_phy_allocate(struct b43_wldev *dev)
{
	struct b43_phy *phy = &(dev->phy);
	int err;

	phy->ops = NULL;

	switch (phy->type) {
	case B43_PHYTYPE_G:
#ifdef CONFIG_B43_PHY_G
		phy->ops = &b43_phyops_g;
#endif
		break;
	case B43_PHYTYPE_N:
#ifdef CONFIG_B43_PHY_N
		phy->ops = &b43_phyops_n;
#endif
		break;
	case B43_PHYTYPE_LP:
#ifdef CONFIG_B43_PHY_LP
		phy->ops = &b43_phyops_lp;
#endif
		break;
	case B43_PHYTYPE_HT:
#ifdef CONFIG_B43_PHY_HT
		phy->ops = &b43_phyops_ht;
#endif
		break;
	case B43_PHYTYPE_LCN:
#ifdef CONFIG_B43_PHY_LCN
		phy->ops = &b43_phyops_lcn;
#endif
		break;
	case B43_PHYTYPE_AC:
#ifdef CONFIG_B43_PHY_AC
		phy->ops = &b43_phyops_ac;
#endif
		break;
	}
	if (B43_WARN_ON(!phy->ops))
		return -ENODEV;

	err = phy->ops->allocate(dev);
	if (err)
		phy->ops = NULL;

	return err;
}

void b43_phy_free(struct b43_wldev *dev)
{
	dev->phy.ops->free(dev);
	dev->phy.ops = NULL;
}

int b43_phy_init(struct b43_wldev *dev)
{
	struct b43_phy *phy = &dev->phy;
	const struct b43_phy_operations *ops = phy->ops;
	int err;

	/* During PHY init we need to use some channel. On the first init this
	 * function is called *before* b43_op_config, so our pointer is NULL.
	 */
	if (!phy->chandef) {
		phy->chandef = &dev->wl->hw->conf.chandef;
		phy->channel = phy->chandef->chan->hw_value;
	}

	phy->ops->switch_analog(dev, true);
	b43_software_rfkill(dev, false);

	err = ops->init(dev);
	if (err) {
		b43err(dev->wl, "PHY init failed\n");
		goto err_block_rf;
	}
	phy->do_full_init = false;

	err = b43_switch_channel(dev, phy->channel);
	if (err) {
		b43err(dev->wl, "PHY init: Channel switch to default failed\n");
		goto err_phy_exit;
	}

	return 0;

err_phy_exit:
	phy->do_full_init = true;
	if (ops->exit)
		ops->exit(dev);
err_block_rf:
	b43_software_rfkill(dev, true);

	return err;
}

void b43_phy_exit(struct b43_wldev *dev)
{
	const struct b43_phy_operations *ops = dev->phy.ops;

	b43_software_rfkill(dev, true);
	dev->phy.do_full_init = true;
	if (ops->exit)
		ops->exit(dev);
}

bool b43_has_hardware_pctl(struct b43_wldev *dev)
{
	if (!dev->phy.hardware_power_control)
		return false;
	if (!dev->phy.ops->supports_hwpctl)
		return false;
	return dev->phy.ops->supports_hwpctl(dev);
}

void b43_radio_lock(struct b43_wldev *dev)
{
	u32 macctl;

#if B43_DEBUG
	B43_WARN_ON(dev->phy.radio_locked);
	dev->phy.radio_locked = true;
#endif

	macctl = b43_read32(dev, B43_MMIO_MACCTL);
	macctl |= B43_MACCTL_RADIOLOCK;
	b43_write32(dev, B43_MMIO_MACCTL, macctl);
	/* Commit the write and wait for the firmware
	 * to finish any radio register access. */
	b43_read32(dev, B43_MMIO_MACCTL);
	udelay(10);
}

void b43_radio_unlock(struct b43_wldev *dev)
{
	u32 macctl;

#if B43_DEBUG
	B43_WARN_ON(!dev->phy.radio_locked);
	dev->phy.radio_locked = false;
#endif

	/* Commit any write */
	b43_read16(dev, B43_MMIO_PHY_VER);
	/* unlock */
	macctl = b43_read32(dev, B43_MMIO_MACCTL);
	macctl &= ~B43_MACCTL_RADIOLOCK;
	b43_write32(dev, B43_MMIO_MACCTL, macctl);
}

void b43_phy_lock(struct b43_wldev *dev)
{
#if B43_DEBUG
	B43_WARN_ON(dev->phy.phy_locked);
	dev->phy.phy_locked = true;
#endif
	B43_WARN_ON(dev->dev->core_rev < 3);

	if (!b43_is_mode(dev->wl, NL80211_IFTYPE_AP))
		b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
}

void b43_phy_unlock(struct b43_wldev *dev)
{
#if B43_DEBUG
	B43_WARN_ON(!dev->phy.phy_locked);
	dev->phy.phy_locked = false;
#endif
	B43_WARN_ON(dev->dev->core_rev < 3);

	if (!b43_is_mode(dev->wl, NL80211_IFTYPE_AP))
		b43_power_saving_ctl_bits(dev, 0);
}

static inline void assert_mac_suspended(struct b43_wldev *dev)
{
	if (!B43_DEBUG)
		return;
	if ((b43_status(dev) >= B43_STAT_INITIALIZED) &&
	    (dev->mac_suspended <= 0)) {
		b43dbg(dev->wl, "PHY/RADIO register access with "
		       "enabled MAC.\n");
		dump_stack();
	}
}

u16 b43_radio_read(struct b43_wldev *dev, u16 reg)
{
	assert_mac_suspended(dev);
	dev->phy.writes_counter = 0;
	return dev->phy.ops->radio_read(dev, reg);
}

void b43_radio_write(struct b43_wldev *dev, u16 reg, u16 value)
{
	assert_mac_suspended(dev);
	if (b43_bus_host_is_pci(dev->dev) &&
	    ++dev->phy.writes_counter > B43_MAX_WRITES_IN_ROW) {
		b43_read32(dev, B43_MMIO_MACCTL);
		dev->phy.writes_counter = 1;
	}
	dev->phy.ops->radio_write(dev, reg, value);
}

void b43_radio_mask(struct b43_wldev *dev, u16 offset, u16 mask)
{
	b43_radio_write16(dev, offset,
			  b43_radio_read16(dev, offset) & mask);
}

void b43_radio_set(struct b43_wldev *dev, u16 offset, u16 set)
{
	b43_radio_write16(dev, offset,
			  b43_radio_read16(dev, offset) | set);
}

void b43_radio_maskset(struct b43_wldev *dev, u16 offset, u16 mask, u16 set)
{
	b43_radio_write16(dev, offset,
			  (b43_radio_read16(dev, offset) & mask) | set);
}

bool b43_radio_wait_value(struct b43_wldev *dev, u16 offset, u16 mask,
			  u16 value, int delay, int timeout)
{
	u16 val;
	int i;

	for (i = 0; i < timeout; i += delay) {
		val = b43_radio_read(dev, offset);
		if ((val & mask) == value)
			return true;
		udelay(delay);
	}
	return false;
}

u16 b43_phy_read(struct b43_wldev *dev, u16 reg)
{
	assert_mac_suspended(dev);
	dev->phy.writes_counter = 0;

	if (dev->phy.ops->phy_read)
		return dev->phy.ops->phy_read(dev, reg);

	b43_write16f(dev, B43_MMIO_PHY_CONTROL, reg);
	return b43_read16(dev, B43_MMIO_PHY_DATA);
}

void b43_phy_write(struct b43_wldev *dev, u16 reg, u16 value)
{
	assert_mac_suspended(dev);
	if (b43_bus_host_is_pci(dev->dev) &&
	    ++dev->phy.writes_counter > B43_MAX_WRITES_IN_ROW) {
		b43_read16(dev, B43_MMIO_PHY_VER);
		dev->phy.writes_counter = 1;
	}

	if (dev->phy.ops->phy_write)
		return dev->phy.ops->phy_write(dev, reg, value);

	b43_write16f(dev, B43_MMIO_PHY_CONTROL, reg);
	b43_write16(dev, B43_MMIO_PHY_DATA, value);
}

void b43_phy_copy(struct b43_wldev *dev, u16 destreg, u16 srcreg)
{
	b43_phy_write(dev, destreg, b43_phy_read(dev, srcreg));
}

void b43_phy_mask(struct b43_wldev *dev, u16 offset, u16 mask)
{
	if (dev->phy.ops->phy_maskset) {
		assert_mac_suspended(dev);
		dev->phy.ops->phy_maskset(dev, offset, mask, 0);
	} else {
		b43_phy_write(dev, offset,
			      b43_phy_read(dev, offset) & mask);
	}
}

void b43_phy_set(struct b43_wldev *dev, u16 offset, u16 set)
{
	if (dev->phy.ops->phy_maskset) {
		assert_mac_suspended(dev);
		dev->phy.ops->phy_maskset(dev, offset, 0xFFFF, set);
	} else {
		b43_phy_write(dev, offset,
			      b43_phy_read(dev, offset) | set);
	}
}

void b43_phy_maskset(struct b43_wldev *dev, u16 offset, u16 mask, u16 set)
{
	if (dev->phy.ops->phy_maskset) {
		assert_mac_suspended(dev);
		dev->phy.ops->phy_maskset(dev, offset, mask, set);
	} else {
		b43_phy_write(dev, offset,
			      (b43_phy_read(dev, offset) & mask) | set);
	}
}

void b43_phy_put_into_reset(struct b43_wldev *dev)
{
	u32 tmp;

	switch (dev->dev->bus_type) {
#ifdef CONFIG_B43_BCMA
	case B43_BUS_BCMA:
		tmp = bcma_aread32(dev->dev->bdev, BCMA_IOCTL);
		tmp &= ~B43_BCMA_IOCTL_GMODE;
		tmp |= B43_BCMA_IOCTL_PHY_RESET;
		tmp |= BCMA_IOCTL_FGC;
		bcma_awrite32(dev->dev->bdev, BCMA_IOCTL, tmp);
		udelay(1);

		tmp = bcma_aread32(dev->dev->bdev, BCMA_IOCTL);
		tmp &= ~BCMA_IOCTL_FGC;
		bcma_awrite32(dev->dev->bdev, BCMA_IOCTL, tmp);
		udelay(1);
		break;
#endif
#ifdef CONFIG_B43_SSB
	case B43_BUS_SSB:
		tmp = ssb_read32(dev->dev->sdev, SSB_TMSLOW);
		tmp &= ~B43_TMSLOW_GMODE;
		tmp |= B43_TMSLOW_PHYRESET;
		tmp |= SSB_TMSLOW_FGC;
		ssb_write32(dev->dev->sdev, SSB_TMSLOW, tmp);
		usleep_range(1000, 2000);

		tmp = ssb_read32(dev->dev->sdev, SSB_TMSLOW);
		tmp &= ~SSB_TMSLOW_FGC;
		ssb_write32(dev->dev->sdev, SSB_TMSLOW, tmp);
		usleep_range(1000, 2000);

		break;
#endif
	}
}

void b43_phy_take_out_of_reset(struct b43_wldev *dev)
{
	u32 tmp;

	switch (dev->dev->bus_type) {
#ifdef CONFIG_B43_BCMA
	case B43_BUS_BCMA:
		/* Unset reset bit (with forcing clock) */
		tmp = bcma_aread32(dev->dev->bdev, BCMA_IOCTL);
		tmp &= ~B43_BCMA_IOCTL_PHY_RESET;
		tmp &= ~B43_BCMA_IOCTL_PHY_CLKEN;
		tmp |= BCMA_IOCTL_FGC;
		bcma_awrite32(dev->dev->bdev, BCMA_IOCTL, tmp);
		udelay(1);

		/* Do not force clock anymore */
		tmp = bcma_aread32(dev->dev->bdev, BCMA_IOCTL);
		tmp &= ~BCMA_IOCTL_FGC;
		tmp |= B43_BCMA_IOCTL_PHY_CLKEN;
		bcma_awrite32(dev->dev->bdev, BCMA_IOCTL, tmp);
		udelay(1);
		break;
#endif
#ifdef CONFIG_B43_SSB
	case B43_BUS_SSB:
		/* Unset reset bit (with forcing clock) */
		tmp = ssb_read32(dev->dev->sdev, SSB_TMSLOW);
		tmp &= ~B43_TMSLOW_PHYRESET;
		tmp &= ~B43_TMSLOW_PHYCLKEN;
		tmp |= SSB_TMSLOW_FGC;
		ssb_write32(dev->dev->sdev, SSB_TMSLOW, tmp);
		ssb_read32(dev->dev->sdev, SSB_TMSLOW); /* flush */
		usleep_range(1000, 2000);

		tmp = ssb_read32(dev->dev->sdev, SSB_TMSLOW);
		tmp &= ~SSB_TMSLOW_FGC;
		tmp |= B43_TMSLOW_PHYCLKEN;
		ssb_write32(dev->dev->sdev, SSB_TMSLOW, tmp);
		ssb_read32(dev->dev->sdev, SSB_TMSLOW); /* flush */
		usleep_range(1000, 2000);
		break;
#endif
	}
}

int b43_switch_channel(struct b43_wldev *dev, unsigned int new_channel)
{
	struct b43_phy *phy = &(dev->phy);
	u16 channelcookie, savedcookie;
	int err;

	/* First we set the channel radio code to prevent the
	 * firmware from sending ghost packets.
	 */
	channelcookie = new_channel;
	if (b43_current_band(dev->wl) == NL80211_BAND_5GHZ)
		channelcookie |= B43_SHM_SH_CHAN_5GHZ;
	/* FIXME: set 40Mhz flag if required */
	if (0)
		channelcookie |= B43_SHM_SH_CHAN_40MHZ;
	savedcookie = b43_shm_read16(dev, B43_SHM_SHARED, B43_SHM_SH_CHAN);
	b43_shm_write16(dev, B43_SHM_SHARED, B43_SHM_SH_CHAN, channelcookie);

	/* Now try to switch the PHY hardware channel. */
	err = phy->ops->switch_channel(dev, new_channel);
	if (err)
		goto err_restore_cookie;

	/* Wait for the radio to tune to the channel and stabilize. */
	msleep(8);

	return 0;

err_restore_cookie:
	b43_shm_write16(dev, B43_SHM_SHARED,
			B43_SHM_SH_CHAN, savedcookie);

	return err;
}

void b43_software_rfkill(struct b43_wldev *dev, bool blocked)
{
	struct b43_phy *phy = &dev->phy;

	b43_mac_suspend(dev);
	phy->ops->software_rfkill(dev, blocked);
	phy->radio_on = !blocked;
	b43_mac_enable(dev);
}

/**
 * b43_phy_txpower_adjust_work - TX power workqueue.
 *
 * Workqueue for updating the TX power parameters in hardware.
 */
void b43_phy_txpower_adjust_work(struct work_struct *work)
{
	struct b43_wl *wl = container_of(work, struct b43_wl,
					 txpower_adjust_work);
	struct b43_wldev *dev;

	mutex_lock(&wl->mutex);
	dev = wl->current_dev;

	if (likely(dev && (b43_status(dev) >= B43_STAT_STARTED)))
		dev->phy.ops->adjust_txpower(dev);

	mutex_unlock(&wl->mutex);
}

void b43_phy_txpower_check(struct b43_wldev *dev, unsigned int flags)
{
	struct b43_phy *phy = &dev->phy;
	unsigned long now = jiffies;
	enum b43_txpwr_result result;

	if (!(flags & B43_TXPWR_IGNORE_TIME)) {
		/* Check if it's time for a TXpower check. */
		if (time_before(now, phy->next_txpwr_check_time))
			return; /* Not yet */
	}
	/* The next check will be needed in two seconds, or later. */
	phy->next_txpwr_check_time = round_jiffies(now + (HZ * 2));

	if ((dev->dev->board_vendor == SSB_BOARDVENDOR_BCM) &&
	    (dev->dev->board_type == SSB_BOARD_BU4306))
		return; /* No software txpower adjustment needed */

	result = phy->ops->recalc_txpower(dev, !!(flags & B43_TXPWR_IGNORE_TSSI));
	if (result == B43_TXPWR_RES_DONE)
		return; /* We are done. */
	B43_WARN_ON(result != B43_TXPWR_RES_NEED_ADJUST);
	B43_WARN_ON(phy->ops->adjust_txpower == NULL);

	/* We must adjust the transmission power in hardware.
	 * Schedule b43_phy_txpower_adjust_work(). */
	ieee80211_queue_work(dev->wl->hw, &dev->wl->txpower_adjust_work);
}

int b43_phy_shm_tssi_read(struct b43_wldev *dev, u16 shm_offset)
{
	const bool is_ofdm = (shm_offset != B43_SHM_SH_TSSI_CCK);
	unsigned int a, b, c, d;
	unsigned int average;
	u32 tmp;

	tmp = b43_shm_read32(dev, B43_SHM_SHARED, shm_offset);
	a = tmp & 0xFF;
	b = (tmp >> 8) & 0xFF;
	c = (tmp >> 16) & 0xFF;
	d = (tmp >> 24) & 0xFF;
	if (a == 0 || a == B43_TSSI_MAX ||
	    b == 0 || b == B43_TSSI_MAX ||
	    c == 0 || c == B43_TSSI_MAX ||
	    d == 0 || d == B43_TSSI_MAX)
		return -ENOENT;
	/* The values are OK. Clear them. */
	tmp = B43_TSSI_MAX | (B43_TSSI_MAX << 8) |
	      (B43_TSSI_MAX << 16) | (B43_TSSI_MAX << 24);
	b43_shm_write32(dev, B43_SHM_SHARED, shm_offset, tmp);

	if (is_ofdm) {
		a = (a + 32) & 0x3F;
		b = (b + 32) & 0x3F;
		c = (c + 32) & 0x3F;
		d = (d + 32) & 0x3F;
	}

	/* Get the average of the values with 0.5 added to each value. */
	average = (a + b + c + d + 2) / 4;
	if (is_ofdm) {
		/* Adjust for CCK-boost */
		if (b43_shm_read16(dev, B43_SHM_SHARED, B43_SHM_SH_HOSTF1)
		    & B43_HF_CCKBOOST)
			average = (average >= 13) ? (average - 13) : 0;
	}

	return average;
}

void b43_phyop_switch_analog_generic(struct b43_wldev *dev, bool on)
{
	b43_write16(dev, B43_MMIO_PHY0, on ? 0 : 0xF4);
}


bool b43_is_40mhz(struct b43_wldev *dev)
{
	return dev->phy.chandef->width == NL80211_CHAN_WIDTH_40;
}

/* http://bcm-v4.sipsolutions.net/802.11/PHY/N/BmacPhyClkFgc */
void b43_phy_force_clock(struct b43_wldev *dev, bool force)
{
	u32 tmp;

	WARN_ON(dev->phy.type != B43_PHYTYPE_N &&
		dev->phy.type != B43_PHYTYPE_HT &&
		dev->phy.type != B43_PHYTYPE_AC);

	switch (dev->dev->bus_type) {
#ifdef CONFIG_B43_BCMA
	case B43_BUS_BCMA:
		tmp = bcma_aread32(dev->dev->bdev, BCMA_IOCTL);
		if (force)
			tmp |= BCMA_IOCTL_FGC;
		else
			tmp &= ~BCMA_IOCTL_FGC;
		bcma_awrite32(dev->dev->bdev, BCMA_IOCTL, tmp);
		break;
#endif
#ifdef CONFIG_B43_SSB
	case B43_BUS_SSB:
		tmp = ssb_read32(dev->dev->sdev, SSB_TMSLOW);
		if (force)
			tmp |= SSB_TMSLOW_FGC;
		else
			tmp &= ~SSB_TMSLOW_FGC;
		ssb_write32(dev->dev->sdev, SSB_TMSLOW, tmp);
		break;
#endif
	}
}

/* http://bcm-v4.sipsolutions.net/802.11/PHY/Cordic */
struct b43_c32 b43_cordic(int theta)
{
	static const u32 arctg[] = {
		2949120, 1740967, 919879, 466945, 234379, 117304,
		  58666,   29335,  14668,   7334,   3667,   1833,
		    917,     458,    229,    115,     57,     29,
	};
	u8 i;
	s32 tmp;
	s8 signx = 1;
	u32 angle = 0;
	struct b43_c32 ret = { .i = 39797, .q = 0, };

	while (theta > (180 << 16))
		theta -= (360 << 16);
	while (theta < -(180 << 16))
		theta += (360 << 16);

	if (theta > (90 << 16)) {
		theta -= (180 << 16);
		signx = -1;
	} else if (theta < -(90 << 16)) {
		theta += (180 << 16);
		signx = -1;
	}

	for (i = 0; i <= 17; i++) {
		if (theta > angle) {
			tmp = ret.i - (ret.q >> i);
			ret.q += ret.i >> i;
			ret.i = tmp;
			angle += arctg[i];
		} else {
			tmp = ret.i + (ret.q >> i);
			ret.q -= ret.i >> i;
			ret.i = tmp;
			angle -= arctg[i];
		}
	}

	ret.i *= signx;
	ret.q *= signx;

	return ret;
}