aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap1/clock.c
blob: 638490e62d5f5ebb7e07a21f586c521b9b2f2fe2 (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
//kernel/linux-omap-fsample/arch/arm/mach-omap1/clock.c#2 - edit change 3808 (text)
/*
 *  linux/arch/arm/mach-omap1/clock.c
 *
 *  Copyright (C) 2004 - 2005 Nokia corporation
 *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
 *
 *  Modified to use omap shared clock framework by
 *  Tony Lindgren <tony@atomide.com>
 *
 * 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/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/clk.h>

#include <asm/io.h>
#include <asm/mach-types.h>

#include <asm/arch/cpu.h>
#include <asm/arch/usb.h>
#include <asm/arch/clock.h>
#include <asm/arch/sram.h>

#include "clock.h"

__u32 arm_idlect1_mask;

/*-------------------------------------------------------------------------
 * Omap1 specific clock functions
 *-------------------------------------------------------------------------*/

static void omap1_watchdog_recalc(struct clk * clk)
{
	clk->rate = clk->parent->rate / 14;
}

static void omap1_uart_recalc(struct clk * clk)
{
	unsigned int val = omap_readl(clk->enable_reg);
	if (val & clk->enable_bit)
		clk->rate = 48000000;
	else
		clk->rate = 12000000;
}

static int omap1_clk_enable_dsp_domain(struct clk *clk)
{
	int retval;

	retval = omap1_clk_enable(&api_ck.clk);
	if (!retval) {
		retval = omap1_clk_enable_generic(clk);
		omap1_clk_disable(&api_ck.clk);
	}

	return retval;
}

static void omap1_clk_disable_dsp_domain(struct clk *clk)
{
	if (omap1_clk_enable(&api_ck.clk) == 0) {
		omap1_clk_disable_generic(clk);
		omap1_clk_disable(&api_ck.clk);
	}
}

static int omap1_clk_enable_uart_functional(struct clk *clk)
{
	int ret;
	struct uart_clk *uclk;

	ret = omap1_clk_enable_generic(clk);
	if (ret == 0) {
		/* Set smart idle acknowledgement mode */
		uclk = (struct uart_clk *)clk;
		omap_writeb((omap_readb(uclk->sysc_addr) & ~0x10) | 8,
			    uclk->sysc_addr);
	}

	return ret;
}

static void omap1_clk_disable_uart_functional(struct clk *clk)
{
	struct uart_clk *uclk;

	/* Set force idle acknowledgement mode */
	uclk = (struct uart_clk *)clk;
	omap_writeb((omap_readb(uclk->sysc_addr) & ~0x18), uclk->sysc_addr);

	omap1_clk_disable_generic(clk);
}

static void omap1_clk_allow_idle(struct clk *clk)
{
	struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;

	if (!(clk->flags & CLOCK_IDLE_CONTROL))
		return;

	if (iclk->no_idle_count > 0 && !(--iclk->no_idle_count))
		arm_idlect1_mask |= 1 << iclk->idlect_shift;
}

static void omap1_clk_deny_idle(struct clk *clk)
{
	struct arm_idlect1_clk * iclk = (struct arm_idlect1_clk *)clk;

	if (!(clk->flags & CLOCK_IDLE_CONTROL))
		return;

	if (iclk->no_idle_count++ == 0)
		arm_idlect1_mask &= ~(1 << iclk->idlect_shift);
}

static __u16 verify_ckctl_value(__u16 newval)
{
	/* This function checks for following limitations set
	 * by the hardware (all conditions must be true):
	 * DSPMMU_CK == DSP_CK  or  DSPMMU_CK == DSP_CK/2
	 * ARM_CK >= TC_CK
	 * DSP_CK >= TC_CK
	 * DSPMMU_CK >= TC_CK
	 *
	 * In addition following rules are enforced:
	 * LCD_CK <= TC_CK
	 * ARMPER_CK <= TC_CK
	 *
	 * However, maximum frequencies are not checked for!
	 */
	__u8 per_exp;
	__u8 lcd_exp;
	__u8 arm_exp;
	__u8 dsp_exp;
	__u8 tc_exp;
	__u8 dspmmu_exp;

	per_exp = (newval >> CKCTL_PERDIV_OFFSET) & 3;
	lcd_exp = (newval >> CKCTL_LCDDIV_OFFSET) & 3;
	arm_exp = (newval >> CKCTL_ARMDIV_OFFSET) & 3;
	dsp_exp = (newval >> CKCTL_DSPDIV_OFFSET) & 3;
	tc_exp = (newval >> CKCTL_TCDIV_OFFSET) & 3;
	dspmmu_exp = (newval >> CKCTL_DSPMMUDIV_OFFSET) & 3;

	if (dspmmu_exp < dsp_exp)
		dspmmu_exp = dsp_exp;
	if (dspmmu_exp > dsp_exp+1)
		dspmmu_exp = dsp_exp+1;
	if (tc_exp < arm_exp)
		tc_exp = arm_exp;
	if (tc_exp < dspmmu_exp)
		tc_exp = dspmmu_exp;
	if (tc_exp > lcd_exp)
		lcd_exp = tc_exp;
	if (tc_exp > per_exp)
		per_exp = tc_exp;

	newval &= 0xf000;
	newval |= per_exp << CKCTL_PERDIV_OFFSET;
	newval |= lcd_exp << CKCTL_LCDDIV_OFFSET;
	newval |= arm_exp << CKCTL_ARMDIV_OFFSET;
	newval |= dsp_exp << CKCTL_DSPDIV_OFFSET;
	newval |= tc_exp << CKCTL_TCDIV_OFFSET;
	newval |= dspmmu_exp << CKCTL_DSPMMUDIV_OFFSET;

	return newval;
}

static int calc_dsor_exp(struct clk *clk, unsigned long rate)
{
	/* Note: If target frequency is too low, this function will return 4,
	 * which is invalid value. Caller must check for this value and act
	 * accordingly.
	 *
	 * Note: This function does not check for following limitations set
	 * by the hardware (all conditions must be true):
	 * DSPMMU_CK == DSP_CK  or  DSPMMU_CK == DSP_CK/2
	 * ARM_CK >= TC_CK
	 * DSP_CK >= TC_CK
	 * DSPMMU_CK >= TC_CK
	 */
	unsigned long realrate;
	struct clk * parent;
	unsigned  dsor_exp;

	if (unlikely(!(clk->flags & RATE_CKCTL)))
		return -EINVAL;

	parent = clk->parent;
	if (unlikely(parent == 0))
		return -EIO;

	realrate = parent->rate;
	for (dsor_exp=0; dsor_exp<4; dsor_exp++) {
		if (realrate <= rate)
			break;

		realrate /= 2;
	}

	return dsor_exp;
}

static void omap1_ckctl_recalc(struct clk * clk)
{
	int dsor;

	/* Calculate divisor encoded as 2-bit exponent */
	dsor = 1 << (3 & (omap_readw(ARM_CKCTL) >> clk->rate_offset));

	if (unlikely(clk->rate == clk->parent->rate / dsor))
		return; /* No change, quick exit */
	clk->rate = clk->parent->rate / dsor;

	if (unlikely(clk->flags & RATE_PROPAGATES))
		propagate_rate(clk);
}

static void omap1_ckctl_recalc_dsp_domain(struct clk * clk)
{
	int dsor;

	/* Calculate divisor encoded as 2-bit exponent
	 *
	 * The clock control bits are in DSP domain,
	 * so api_ck is needed for access.
	 * Note that DSP_CKCTL virt addr = phys addr, so
	 * we must use __raw_readw() instead of omap_readw().
	 */
	omap1_clk_enable(&api_ck.clk);
	dsor = 1 << (3 & (__raw_readw(DSP_CKCTL) >> clk->rate_offset));
	omap1_clk_disable(&api_ck.clk);

	if (unlikely(clk->rate == clk->parent->rate / dsor))
		return; /* No change, quick exit */
	clk->rate = clk->parent->rate / dsor;

	if (unlikely(clk->flags & RATE_PROPAGATES))
		propagate_rate(clk);
}

/* MPU virtual clock functions */
static int omap1_select_table_rate(struct clk * clk, unsigned long rate)
{
	/* Find the highest supported frequency <= rate and switch to it */
	struct mpu_rate * ptr;

	if (clk != &virtual_ck_mpu)
		return -EINVAL;

	for (ptr = rate_table; ptr->rate; ptr++) {
		if (ptr->xtal != ck_ref.rate)
			continue;

		/* DPLL1 cannot be reprogrammed without risking system crash */
		if (likely(ck_dpll1.rate!=0) && ptr->pll_rate != ck_dpll1.rate)
			continue;

		/* Can check only after xtal frequency check */
		if (ptr->rate <= rate)
			break;
	}

	if (!ptr->rate)
		return -EINVAL;

	/*
	 * In most cases we should not need to reprogram DPLL.
	 * Reprogramming the DPLL is tricky, it must be done from SRAM.
	 * (on 730, bit 13 must always be 1)
	 */
	if (cpu_is_omap730())
		omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val | 0x2000);
	else
		omap_sram_reprogram_clock(ptr->dpllctl_val, ptr->ckctl_val);

	ck_dpll1.rate = ptr->pll_rate;
	propagate_rate(&ck_dpll1);
	return 0;
}

static int omap1_clk_set_rate_dsp_domain(struct clk *clk, unsigned long rate)
{
	int  ret = -EINVAL;
	int  dsor_exp;
	__u16  regval;

	if (clk->flags & RATE_CKCTL) {
		dsor_exp = calc_dsor_exp(clk, rate);
		if (dsor_exp > 3)
			dsor_exp = -EINVAL;
		if (dsor_exp < 0)
			return dsor_exp;

		regval = __raw_readw(DSP_CKCTL);
		regval &= ~(3 << clk->rate_offset);
		regval |= dsor_exp << clk->rate_offset;
		__raw_writew(regval, DSP_CKCTL);
		clk->rate = clk->parent->rate / (1 << dsor_exp);
		ret = 0;
	}

	if (unlikely(ret == 0 && (clk->flags & RATE_PROPAGATES)))
		propagate_rate(clk);

	return ret;
}

static long omap1_round_to_table_rate(struct clk * clk, unsigned long rate)
{
	/* Find the highest supported frequency <= rate */
	struct mpu_rate * ptr;
	long  highest_rate;

	if (clk != &virtual_ck_mpu)
		return -EINVAL;

	highest_rate = -EINVAL;

	for (ptr = rate_table; ptr->rate; ptr++) {
		if (ptr->xtal != ck_ref.rate)
			continue;

		highest_rate = ptr->rate;

		/* Can check only after xtal frequency check */
		if (ptr->rate <= rate)
			break;
	}

	return highest_rate;
}

static unsigned calc_ext_dsor(unsigned long rate)
{
	unsigned dsor;

	/* MCLK and BCLK divisor selection is not linear:
	 * freq = 96MHz / dsor
	 *
	 * RATIO_SEL range: dsor <-> RATIO_SEL
	 * 0..6: (RATIO_SEL+2) <-> (dsor-2)
	 * 6..48:  (8+(RATIO_SEL-6)*2) <-> ((dsor-8)/2+6)
	 * Minimum dsor is 2 and maximum is 96. Odd divisors starting from 9
	 * can not be used.
	 */
	for (dsor = 2; dsor < 96; ++dsor) {
		if ((dsor & 1) && dsor > 8)
			continue;
		if (rate >= 96000000 / dsor)
			break;
	}
	return dsor;
}

/* Only needed on 1510 */
static int omap1_set_uart_rate(struct clk * clk, unsigned long rate)
{
	unsigned int val;

	val = omap_readl(clk->enable_reg);
	if (rate == 12000000)
		val &= ~(1 << clk->enable_bit);
	else if (rate == 48000000)
		val |= (1 << clk->enable_bit);
	else
		return -EINVAL;
	omap_writel(val, clk->enable_reg);
	clk->rate = rate;

	return 0;
}

/* External clock (MCLK & BCLK) functions */
static int omap1_set_ext_clk_rate(struct clk * clk, unsigned long rate)
{
	unsigned dsor;
	__u16 ratio_bits;

	dsor = calc_ext_dsor(rate);
	clk->rate = 96000000 / dsor;
	if (dsor > 8)
		ratio_bits = ((dsor - 8) / 2 + 6) << 2;
	else
		ratio_bits = (dsor - 2) << 2;

	ratio_bits |= omap_readw(clk->enable_reg) & ~0xfd;
	omap_writew(ratio_bits, clk->enable_reg);

	return 0;
}

static long omap1_round_ext_clk_rate(struct clk * clk, unsigned long rate)
{
	return 96000000 / calc_ext_dsor(rate);
}

static void omap1_init_ext_clk(struct clk * clk)
{
	unsigned dsor;
	__u16 ratio_bits;

	/* Determine current rate and ensure clock is based on 96MHz APLL */
	ratio_bits = omap_readw(clk->enable_reg) & ~1;
	omap_writew(ratio_bits, clk->enable_reg);

	ratio_bits = (ratio_bits & 0xfc) >> 2;
	if (ratio_bits > 6)
		dsor = (ratio_bits - 6) * 2 + 8;
	else
		dsor = ratio_bits + 2;

	clk-> rate = 96000000 / dsor;
}

static int omap1_clk_enable(struct clk *clk)
{
	int ret = 0;
	if (clk->usecount++ == 0) {
		if (likely(clk->parent)) {
			ret = omap1_clk_enable(clk->parent);

			if (unlikely(ret != 0)) {
				clk->usecount--;
				return ret;
			}

			if (clk->flags & CLOCK_NO_IDLE_PARENT)
				if (!cpu_is_omap24xx())
					omap1_clk_deny_idle(clk->parent);
		}

		ret = clk->enable(clk);

		if (unlikely(ret != 0) && clk->parent) {
			omap1_clk_disable(clk->parent);
			clk->usecount--;
		}
	}

	return ret;
}

static void omap1_clk_disable(struct clk *clk)
{
	if (clk->usecount > 0 && !(--clk->usecount)) {
		clk->disable(clk);
		if (likely(clk->parent)) {
			omap1_clk_disable(clk->parent);
			if (clk->flags & CLOCK_NO_IDLE_PARENT)
				if (!cpu_is_omap24xx())
					omap1_clk_allow_idle(clk->parent);
		}
	}
}

static int omap1_clk_enable_generic(struct clk *clk)
{
	__u16 regval16;
	__u32 regval32;

	if (clk->flags & ALWAYS_ENABLED)
		return 0;

	if (unlikely(clk->enable_reg == 0)) {
		printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
		       clk->name);
		return 0;
	}

	if (clk->flags & ENABLE_REG_32BIT) {
		if (clk->flags & VIRTUAL_IO_ADDRESS) {
			regval32 = __raw_readl(clk->enable_reg);
			regval32 |= (1 << clk->enable_bit);
			__raw_writel(regval32, clk->enable_reg);
		} else {
			regval32 = omap_readl(clk->enable_reg);
			regval32 |= (1 << clk->enable_bit);
			omap_writel(regval32, clk->enable_reg);
		}
	} else {
		if (clk->flags & VIRTUAL_IO_ADDRESS) {
			regval16 = __raw_readw(clk->enable_reg);
			regval16 |= (1 << clk->enable_bit);
			__raw_writew(regval16, clk->enable_reg);
		} else {
			regval16 = omap_readw(clk->enable_reg);
			regval16 |= (1 << clk->enable_bit);
			omap_writew(regval16, clk->enable_reg);
		}
	}

	return 0;
}

static void omap1_clk_disable_generic(struct clk *clk)
{
	__u16 regval16;
	__u32 regval32;

	if (clk->enable_reg == 0)
		return;

	if (clk->flags & ENABLE_REG_32BIT) {
		if (clk->flags & VIRTUAL_IO_ADDRESS) {
			regval32 = __raw_readl(clk->enable_reg);
			regval32 &= ~(1 << clk->enable_bit);
			__raw_writel(regval32, clk->enable_reg);
		} else {
			regval32 = omap_readl(clk->enable_reg);
			regval32 &= ~(1 << clk->enable_bit);
			omap_writel(regval32, clk->enable_reg);
		}
	} else {
		if (clk->flags & VIRTUAL_IO_ADDRESS) {
			regval16 = __raw_readw(clk->enable_reg);
			regval16 &= ~(1 << clk->enable_bit);
			__raw_writew(regval16, clk->enable_reg);
		} else {
			regval16 = omap_readw(clk->enable_reg);
			regval16 &= ~(1 << clk->enable_bit);
			omap_writew(regval16, clk->enable_reg);
		}
	}
}

static long omap1_clk_round_rate(struct clk *clk, unsigned long rate)
{
	int dsor_exp;

	if (clk->flags & RATE_FIXED)
		return clk->rate;

	if (clk->flags & RATE_CKCTL) {
		dsor_exp = calc_dsor_exp(clk, rate);
		if (dsor_exp < 0)
			return dsor_exp;
		if (dsor_exp > 3)
			dsor_exp = 3;
		return clk->parent->rate / (1 << dsor_exp);
	}

	if(clk->round_rate != 0)
		return clk->round_rate(clk, rate);

	return clk->rate;
}

static int omap1_clk_set_rate(struct clk *clk, unsigned long rate)
{
	int  ret = -EINVAL;
	int  dsor_exp;
	__u16  regval;

	if (clk->set_rate)
		ret = clk->set_rate(clk, rate);
	else if (clk->flags & RATE_CKCTL) {
		dsor_exp = calc_dsor_exp(clk, rate);
		if (dsor_exp > 3)
			dsor_exp = -EINVAL;
		if (dsor_exp < 0)
			return dsor_exp;

		regval = omap_readw(ARM_CKCTL);
		regval &= ~(3 << clk->rate_offset);
		regval |= dsor_exp << clk->rate_offset;
		regval = verify_ckctl_value(regval);
		omap_writew(regval, ARM_CKCTL);
		clk->rate = clk->parent->rate / (1 << dsor_exp);
		ret = 0;
	}

	if (unlikely(ret == 0 && (clk->flags & RATE_PROPAGATES)))
		propagate_rate(clk);

	return ret;
}

/*-------------------------------------------------------------------------
 * Omap1 clock reset and init functions
 *-------------------------------------------------------------------------*/

#ifdef CONFIG_OMAP_RESET_CLOCKS

static void __init omap1_clk_disable_unused(struct clk *clk)
{
	__u32 regval32;

	/* Clocks in the DSP domain need api_ck. Just assume bootloader
	 * has not enabled any DSP clocks */
	if ((u32)clk->enable_reg == DSP_IDLECT2) {
		printk(KERN_INFO "Skipping reset check for DSP domain "
		       "clock \"%s\"\n", clk->name);
		return;
	}

	/* Is the clock already disabled? */
	if (clk->flags & ENABLE_REG_32BIT) {
		if (clk->flags & VIRTUAL_IO_ADDRESS)
			regval32 = __raw_readl(clk->enable_reg);
			else
				regval32 = omap_readl(clk->enable_reg);
	} else {
		if (clk->flags & VIRTUAL_IO_ADDRESS)
			regval32 = __raw_readw(clk->enable_reg);
		else
			regval32 = omap_readw(clk->enable_reg);
	}

	if ((regval32 & (1 << clk->enable_bit)) == 0)
		return;

	/* FIXME: This clock seems to be necessary but no-one
	 * has asked for its activation. */
	if (clk == &tc2_ck		// FIX: pm.c (SRAM), CCP, Camera
	    || clk == &ck_dpll1out.clk	// FIX: SoSSI, SSR
	    || clk == &arm_gpio_ck	// FIX: GPIO code for 1510
		) {
		printk(KERN_INFO "FIXME: Clock \"%s\" seems unused\n",
		       clk->name);
		return;
	}

	printk(KERN_INFO "Disabling unused clock \"%s\"... ", clk->name);
	clk->disable(clk);
	printk(" done\n");
}

#else
#define omap1_clk_disable_unused	NULL
#endif

static struct clk_functions omap1_clk_functions = {
	.clk_enable		= omap1_clk_enable,
	.clk_disable		= omap1_clk_disable,
	.clk_round_rate		= omap1_clk_round_rate,
	.clk_set_rate		= omap1_clk_set_rate,
	.clk_disable_unused	= omap1_clk_disable_unused,
};

int __init omap1_clk_init(void)
{
	struct clk ** clkp;
	const struct omap_clock_config *info;
	int crystal_type = 0; /* Default 12 MHz */
	u32 reg;

	/* USB_REQ_EN will be disabled later if necessary (usb_dc_ck) */
	reg = omap_readw(SOFT_REQ_REG) & (1 << 4);
	omap_writew(reg, SOFT_REQ_REG);
	omap_writew(0, SOFT_REQ_REG2);

	clk_init(&omap1_clk_functions);

	/* By default all idlect1 clocks are allowed to idle */
	arm_idlect1_mask = ~0;

	for (clkp = onchip_clks; clkp < onchip_clks+ARRAY_SIZE(onchip_clks); clkp++) {
		if (((*clkp)->flags &CLOCK_IN_OMAP1510) && cpu_is_omap1510()) {
			clk_register(*clkp);
			continue;
		}

		if (((*clkp)->flags &CLOCK_IN_OMAP16XX) && cpu_is_omap16xx()) {
			clk_register(*clkp);
			continue;
		}

		if (((*clkp)->flags &CLOCK_IN_OMAP730) && cpu_is_omap730()) {
			clk_register(*clkp);
			continue;
		}

		if (((*clkp)->flags &CLOCK_IN_OMAP310) && cpu_is_omap310()) {
			clk_register(*clkp);
			continue;
		}
	}

	info = omap_get_config(OMAP_TAG_CLOCK, struct omap_clock_config);
	if (info != NULL) {
		if (!cpu_is_omap1510())
			crystal_type = info->system_clock_type;
	}

#if defined(CONFIG_ARCH_OMAP730)
	ck_ref.rate = 13000000;
#elif defined(CONFIG_ARCH_OMAP16XX)
	if (crystal_type == 2)
		ck_ref.rate = 19200000;
#endif

	printk("Clocks: ARM_SYSST: 0x%04x DPLL_CTL: 0x%04x ARM_CKCTL: 0x%04x\n",
	       omap_readw(ARM_SYSST), omap_readw(DPLL_CTL),
	       omap_readw(ARM_CKCTL));

	/* We want to be in syncronous scalable mode */
	omap_writew(0x1000, ARM_SYSST);

#ifdef CONFIG_OMAP_CLOCKS_SET_BY_BOOTLOADER
	/* Use values set by bootloader. Determine PLL rate and recalculate
	 * dependent clocks as if kernel had changed PLL or divisors.
	 */
	{
		unsigned pll_ctl_val = omap_readw(DPLL_CTL);

		ck_dpll1.rate = ck_ref.rate; /* Base xtal rate */
		if (pll_ctl_val & 0x10) {
			/* PLL enabled, apply multiplier and divisor */
			if (pll_ctl_val & 0xf80)
				ck_dpll1.rate *= (pll_ctl_val & 0xf80) >> 7;
			ck_dpll1.rate /= ((pll_ctl_val & 0x60) >> 5) + 1;
		} else {
			/* PLL disabled, apply bypass divisor */
			switch (pll_ctl_val & 0xc) {
			case 0:
				break;
			case 0x4:
				ck_dpll1.rate /= 2;
				break;
			default:
				ck_dpll1.rate /= 4;
				break;
			}
		}
	}
	propagate_rate(&ck_dpll1);
#else
	/* Find the highest supported frequency and enable it */
	if (omap1_select_table_rate(&virtual_ck_mpu, ~0)) {
		printk(KERN_ERR "System frequencies not set. Check your config.\n");
		/* Guess sane values (60MHz) */
		omap_writew(0x2290, DPLL_CTL);
		omap_writew(cpu_is_omap730() ? 0x3005 : 0x1005, ARM_CKCTL);
		ck_dpll1.rate = 60000000;
		propagate_rate(&ck_dpll1);
	}
#endif
	/* Cache rates for clocks connected to ck_ref (not dpll1) */
	propagate_rate(&ck_ref);
	printk(KERN_INFO "Clocking rate (xtal/DPLL1/MPU): "
		"%ld.%01ld/%ld.%01ld/%ld.%01ld MHz\n",
	       ck_ref.rate / 1000000, (ck_ref.rate / 100000) % 10,
	       ck_dpll1.rate / 1000000, (ck_dpll1.rate / 100000) % 10,
	       arm_ck.rate / 1000000, (arm_ck.rate / 100000) % 10);

#if defined(CONFIG_MACH_OMAP_PERSEUS2) || defined(CONFIG_MACH_OMAP_FSAMPLE)
	/* Select slicer output as OMAP input clock */
	omap_writew(omap_readw(OMAP730_PCC_UPLD_CTRL) & ~0x1, OMAP730_PCC_UPLD_CTRL);
#endif

	/* Amstrad Delta wants BCLK high when inactive */
	if (machine_is_ams_delta())
		omap_writel(omap_readl(ULPD_CLOCK_CTRL) |
				(1 << SDW_MCLK_INV_BIT),
				ULPD_CLOCK_CTRL);

	/* Turn off DSP and ARM_TIMXO. Make sure ARM_INTHCK is not divided */
	/* (on 730, bit 13 must not be cleared) */
	if (cpu_is_omap730())
		omap_writew(omap_readw(ARM_CKCTL) & 0x2fff, ARM_CKCTL);
	else
		omap_writew(omap_readw(ARM_CKCTL) & 0x0fff, ARM_CKCTL);

	/* Put DSP/MPUI into reset until needed */
	omap_writew(0, ARM_RSTCT1);
	omap_writew(1, ARM_RSTCT2);
	omap_writew(0x400, ARM_IDLECT1);

	/*
	 * According to OMAP5910 Erratum SYS_DMA_1, bit DMACK_REQ (bit 8)
	 * of the ARM_IDLECT2 register must be set to zero. The power-on
	 * default value of this bit is one.
	 */
	omap_writew(0x0000, ARM_IDLECT2);	/* Turn LCD clock off also */

	/*
	 * Only enable those clocks we will need, let the drivers
	 * enable other clocks as necessary
	 */
	clk_enable(&armper_ck.clk);
	clk_enable(&armxor_ck.clk);
	clk_enable(&armtim_ck.clk); /* This should be done by timer code */

	if (cpu_is_omap15xx())
		clk_enable(&arm_gpio_ck);

	return 0;
}