aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-omap2/dpll3xxx.c
blob: ef666455c13a9ea1f9bff8887b615c97b7119111 (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
/*
 * OMAP3/4 - specific DPLL control functions
 *
 * Copyright (C) 2009-2010 Texas Instruments, Inc.
 * Copyright (C) 2009-2010 Nokia Corporation
 *
 * Written by Paul Walmsley
 * Testing and integration fixes by Jouni Högander
 *
 * 36xx support added by Vishwanath BS, Richard Woodruff, and Nishanth
 * Menon
 *
 * Parts of this code are based on code written by
 * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
 *
 * 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/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/clkdev.h>

#include <plat/clock.h>

#include "soc.h"
#include "clock.h"
#include "cm2xxx_3xxx.h"
#include "cm-regbits-34xx.h"

/* CM_AUTOIDLE_PLL*.AUTO_* bit values */
#define DPLL_AUTOIDLE_DISABLE			0x0
#define DPLL_AUTOIDLE_LOW_POWER_STOP		0x1

#define MAX_DPLL_WAIT_TRIES		1000000

/* Private functions */

/* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits)
{
	const struct dpll_data *dd;
	u32 v;

	dd = clk->dpll_data;

	v = __raw_readl(dd->control_reg);
	v &= ~dd->enable_mask;
	v |= clken_bits << __ffs(dd->enable_mask);
	__raw_writel(v, dd->control_reg);
}

/* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
{
	const struct dpll_data *dd;
	int i = 0;
	int ret = -EINVAL;

	dd = clk->dpll_data;

	state <<= __ffs(dd->idlest_mask);

	while (((__raw_readl(dd->idlest_reg) & dd->idlest_mask) != state) &&
	       i < MAX_DPLL_WAIT_TRIES) {
		i++;
		udelay(1);
	}

	if (i == MAX_DPLL_WAIT_TRIES) {
		printk(KERN_ERR "clock: %s failed transition to '%s'\n",
		       clk->name, (state) ? "locked" : "bypassed");
	} else {
		pr_debug("clock: %s transition to '%s' in %d loops\n",
			 clk->name, (state) ? "locked" : "bypassed", i);

		ret = 0;
	}

	return ret;
}

/* From 3430 TRM ES2 4.7.6.2 */
static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
{
	unsigned long fint;
	u16 f = 0;

	fint = clk->dpll_data->clk_ref->rate / n;

	pr_debug("clock: fint is %lu\n", fint);

	if (fint >= 750000 && fint <= 1000000)
		f = 0x3;
	else if (fint > 1000000 && fint <= 1250000)
		f = 0x4;
	else if (fint > 1250000 && fint <= 1500000)
		f = 0x5;
	else if (fint > 1500000 && fint <= 1750000)
		f = 0x6;
	else if (fint > 1750000 && fint <= 2100000)
		f = 0x7;
	else if (fint > 7500000 && fint <= 10000000)
		f = 0xB;
	else if (fint > 10000000 && fint <= 12500000)
		f = 0xC;
	else if (fint > 12500000 && fint <= 15000000)
		f = 0xD;
	else if (fint > 15000000 && fint <= 17500000)
		f = 0xE;
	else if (fint > 17500000 && fint <= 21000000)
		f = 0xF;
	else
		pr_debug("clock: unknown freqsel setting for %d\n", n);

	return f;
}

/*
 * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to lock.  Waits for the DPLL to report
 * readiness before returning.  Will save and restore the DPLL's
 * autoidle state across the enable, per the CDP code.  If the DPLL
 * locked successfully, return 0; if the DPLL did not lock in the time
 * allotted, or DPLL3 was passed in, return -EINVAL.
 */
static int _omap3_noncore_dpll_lock(struct clk *clk)
{
	const struct dpll_data *dd;
	u8 ai;
	u8 state = 1;
	int r = 0;

	pr_debug("clock: locking DPLL %s\n", clk->name);

	dd = clk->dpll_data;
	state <<= __ffs(dd->idlest_mask);

	/* Check if already locked */
	if ((__raw_readl(dd->idlest_reg) & dd->idlest_mask) == state)
		goto done;

	ai = omap3_dpll_autoidle_read(clk);

	if (ai)
		omap3_dpll_deny_idle(clk);

	_omap3_dpll_write_clken(clk, DPLL_LOCKED);

	r = _omap3_wait_dpll_status(clk, 1);

	if (ai)
		omap3_dpll_allow_idle(clk);

done:
	return r;
}

/*
 * _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to enter low-power bypass mode.  In
 * bypass mode, the DPLL's rate is set equal to its parent clock's
 * rate.  Waits for the DPLL to report readiness before returning.
 * Will save and restore the DPLL's autoidle state across the enable,
 * per the CDP code.  If the DPLL entered bypass mode successfully,
 * return 0; if the DPLL did not enter bypass in the time allotted, or
 * DPLL3 was passed in, or the DPLL does not support low-power bypass,
 * return -EINVAL.
 */
static int _omap3_noncore_dpll_bypass(struct clk *clk)
{
	int r;
	u8 ai;

	if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
		return -EINVAL;

	pr_debug("clock: configuring DPLL %s for low-power bypass\n",
		 clk->name);

	ai = omap3_dpll_autoidle_read(clk);

	_omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);

	r = _omap3_wait_dpll_status(clk, 0);

	if (ai)
		omap3_dpll_allow_idle(clk);

	return r;
}

/*
 * _omap3_noncore_dpll_stop - instruct a DPLL to stop
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to enter low-power stop. Will save and
 * restore the DPLL's autoidle state across the stop, per the CDP
 * code.  If DPLL3 was passed in, or the DPLL does not support
 * low-power stop, return -EINVAL; otherwise, return 0.
 */
static int _omap3_noncore_dpll_stop(struct clk *clk)
{
	u8 ai;

	if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
		return -EINVAL;

	pr_debug("clock: stopping DPLL %s\n", clk->name);

	ai = omap3_dpll_autoidle_read(clk);

	_omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);

	if (ai)
		omap3_dpll_allow_idle(clk);

	return 0;
}

/**
 * _lookup_dco - Lookup DCO used by j-type DPLL
 * @clk: pointer to a DPLL struct clk
 * @dco: digital control oscillator selector
 * @m: DPLL multiplier to set
 * @n: DPLL divider to set
 *
 * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
 *
 * XXX This code is not needed for 3430/AM35xx; can it be optimized
 * out in non-multi-OMAP builds for those chips?
 */
static void _lookup_dco(struct clk *clk, u8 *dco, u16 m, u8 n)
{
	unsigned long fint, clkinp; /* watch out for overflow */

	clkinp = clk->parent->rate;
	fint = (clkinp / n) * m;

	if (fint < 1000000000)
		*dco = 2;
	else
		*dco = 4;
}

/**
 * _lookup_sddiv - Calculate sigma delta divider for j-type DPLL
 * @clk: pointer to a DPLL struct clk
 * @sd_div: target sigma-delta divider
 * @m: DPLL multiplier to set
 * @n: DPLL divider to set
 *
 * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
 *
 * XXX This code is not needed for 3430/AM35xx; can it be optimized
 * out in non-multi-OMAP builds for those chips?
 */
static void _lookup_sddiv(struct clk *clk, u8 *sd_div, u16 m, u8 n)
{
	unsigned long clkinp, sd; /* watch out for overflow */
	int mod1, mod2;

	clkinp = clk->parent->rate;

	/*
	 * target sigma-delta to near 250MHz
	 * sd = ceil[(m/(n+1)) * (clkinp_MHz / 250)]
	 */
	clkinp /= 100000; /* shift from MHz to 10*Hz for 38.4 and 19.2 */
	mod1 = (clkinp * m) % (250 * n);
	sd = (clkinp * m) / (250 * n);
	mod2 = sd % 10;
	sd /= 10;

	if (mod1 || mod2)
		sd++;
	*sd_div = sd;
}

/*
 * _omap3_noncore_dpll_program - set non-core DPLL M,N values directly
 * @clk: struct clk * of DPLL to set
 * @m: DPLL multiplier to set
 * @n: DPLL divider to set
 * @freqsel: FREQSEL value to set
 *
 * Program the DPLL with the supplied M, N values, and wait for the DPLL to
 * lock..  Returns -EINVAL upon error, or 0 upon success.
 */
static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
{
	struct dpll_data *dd = clk->dpll_data;
	u8 dco, sd_div;
	u32 v;

	/* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
	_omap3_noncore_dpll_bypass(clk);

	/*
	 * Set jitter correction. No jitter correction for OMAP4 and 3630
	 * since freqsel field is no longer present
	 */
	if (!cpu_is_omap44xx() && !cpu_is_omap3630()) {
		v = __raw_readl(dd->control_reg);
		v &= ~dd->freqsel_mask;
		v |= freqsel << __ffs(dd->freqsel_mask);
		__raw_writel(v, dd->control_reg);
	}

	/* Set DPLL multiplier, divider */
	v = __raw_readl(dd->mult_div1_reg);
	v &= ~(dd->mult_mask | dd->div1_mask);
	v |= m << __ffs(dd->mult_mask);
	v |= (n - 1) << __ffs(dd->div1_mask);

	/* Configure dco and sd_div for dplls that have these fields */
	if (dd->dco_mask) {
		_lookup_dco(clk, &dco, m, n);
		v &= ~(dd->dco_mask);
		v |= dco << __ffs(dd->dco_mask);
	}
	if (dd->sddiv_mask) {
		_lookup_sddiv(clk, &sd_div, m, n);
		v &= ~(dd->sddiv_mask);
		v |= sd_div << __ffs(dd->sddiv_mask);
	}

	__raw_writel(v, dd->mult_div1_reg);

	/* We let the clock framework set the other output dividers later */

	/* REVISIT: Set ramp-up delay? */

	_omap3_noncore_dpll_lock(clk);

	return 0;
}

/* Public functions */

/**
 * omap3_dpll_recalc - recalculate DPLL rate
 * @clk: DPLL struct clk
 *
 * Recalculate and propagate the DPLL rate.
 */
unsigned long omap3_dpll_recalc(struct clk *clk)
{
	return omap2_get_dpll_rate(clk);
}

/* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */

/**
 * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
 * The choice of modes depends on the DPLL's programmed rate: if it is
 * the same as the DPLL's parent clock, it will enter bypass;
 * otherwise, it will enter lock.  This code will wait for the DPLL to
 * indicate readiness before returning, unless the DPLL takes too long
 * to enter the target state.  Intended to be used as the struct clk's
 * enable function.  If DPLL3 was passed in, or the DPLL does not
 * support low-power stop, or if the DPLL took too long to enter
 * bypass or lock, return -EINVAL; otherwise, return 0.
 */
int omap3_noncore_dpll_enable(struct clk *clk)
{
	int r;
	struct dpll_data *dd;

	dd = clk->dpll_data;
	if (!dd)
		return -EINVAL;

	if (clk->rate == dd->clk_bypass->rate) {
		WARN_ON(clk->parent != dd->clk_bypass);
		r = _omap3_noncore_dpll_bypass(clk);
	} else {
		WARN_ON(clk->parent != dd->clk_ref);
		r = _omap3_noncore_dpll_lock(clk);
	}
	/*
	 *FIXME: this is dubious - if clk->rate has changed, what about
	 * propagating?
	 */
	if (!r)
		clk->rate = (clk->recalc) ? clk->recalc(clk) :
			omap2_get_dpll_rate(clk);

	return r;
}

/**
 * omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop
 * @clk: pointer to a DPLL struct clk
 *
 * Instructs a non-CORE DPLL to enter low-power stop.  This function is
 * intended for use in struct clkops.  No return value.
 */
void omap3_noncore_dpll_disable(struct clk *clk)
{
	_omap3_noncore_dpll_stop(clk);
}


/* Non-CORE DPLL rate set code */

/**
 * omap3_noncore_dpll_set_rate - set non-core DPLL rate
 * @clk: struct clk * of DPLL to set
 * @rate: rounded target rate
 *
 * Set the DPLL CLKOUT to the target rate.  If the DPLL can enter
 * low-power bypass, and the target rate is the bypass source clock
 * rate, then configure the DPLL for bypass.  Otherwise, round the
 * target rate if it hasn't been done already, then program and lock
 * the DPLL.  Returns -EINVAL upon error, or 0 upon success.
 */
int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate)
{
	struct clk *new_parent = NULL;
	unsigned long hw_rate;
	u16 freqsel = 0;
	struct dpll_data *dd;
	int ret;

	if (!clk || !rate)
		return -EINVAL;

	dd = clk->dpll_data;
	if (!dd)
		return -EINVAL;

	hw_rate = (clk->recalc) ? clk->recalc(clk) : omap2_get_dpll_rate(clk);
	if (rate == hw_rate)
		return 0;

	/*
	 * Ensure both the bypass and ref clocks are enabled prior to
	 * doing anything; we need the bypass clock running to reprogram
	 * the DPLL.
	 */
	omap2_clk_enable(dd->clk_bypass);
	omap2_clk_enable(dd->clk_ref);

	if (dd->clk_bypass->rate == rate &&
	    (clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
		pr_debug("clock: %s: set rate: entering bypass.\n", clk->name);

		ret = _omap3_noncore_dpll_bypass(clk);
		if (!ret)
			new_parent = dd->clk_bypass;
	} else {
		if (dd->last_rounded_rate != rate)
			rate = clk->round_rate(clk, rate);

		if (dd->last_rounded_rate == 0)
			return -EINVAL;

		/* No freqsel on OMAP4 and OMAP3630 */
		if (!cpu_is_omap44xx() && !cpu_is_omap3630()) {
			freqsel = _omap3_dpll_compute_freqsel(clk,
						dd->last_rounded_n);
			if (!freqsel)
				WARN_ON(1);
		}

		pr_debug("clock: %s: set rate: locking rate to %lu.\n",
			 clk->name, rate);

		ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
						 dd->last_rounded_n, freqsel);
		if (!ret)
			new_parent = dd->clk_ref;
	}
	if (!ret) {
		/*
		 * Switch the parent clock in the hierarchy, and make sure
		 * that the new parent's usecount is correct.  Note: we
		 * enable the new parent before disabling the old to avoid
		 * any unnecessary hardware disable->enable transitions.
		 */
		if (clk->usecount) {
			omap2_clk_enable(new_parent);
			omap2_clk_disable(clk->parent);
		}
		clk_reparent(clk, new_parent);
		clk->rate = rate;
	}
	omap2_clk_disable(dd->clk_ref);
	omap2_clk_disable(dd->clk_bypass);

	return 0;
}

/* DPLL autoidle read/set code */

/**
 * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
 * @clk: struct clk * of the DPLL to read
 *
 * Return the DPLL's autoidle bits, shifted down to bit 0.  Returns
 * -EINVAL if passed a null pointer or if the struct clk does not
 * appear to refer to a DPLL.
 */
u32 omap3_dpll_autoidle_read(struct clk *clk)
{
	const struct dpll_data *dd;
	u32 v;

	if (!clk || !clk->dpll_data)
		return -EINVAL;

	dd = clk->dpll_data;

	if (!dd->autoidle_reg)
		return -EINVAL;

	v = __raw_readl(dd->autoidle_reg);
	v &= dd->autoidle_mask;
	v >>= __ffs(dd->autoidle_mask);

	return v;
}

/**
 * omap3_dpll_allow_idle - enable DPLL autoidle bits
 * @clk: struct clk * of the DPLL to operate on
 *
 * Enable DPLL automatic idle control.  This automatic idle mode
 * switching takes effect only when the DPLL is locked, at least on
 * OMAP3430.  The DPLL will enter low-power stop when its downstream
 * clocks are gated.  No return value.
 */
void omap3_dpll_allow_idle(struct clk *clk)
{
	const struct dpll_data *dd;
	u32 v;

	if (!clk || !clk->dpll_data)
		return;

	dd = clk->dpll_data;

	if (!dd->autoidle_reg) {
		pr_debug("clock: DPLL %s: autoidle not supported\n",
			clk->name);
		return;
	}

	/*
	 * REVISIT: CORE DPLL can optionally enter low-power bypass
	 * by writing 0x5 instead of 0x1.  Add some mechanism to
	 * optionally enter this mode.
	 */
	v = __raw_readl(dd->autoidle_reg);
	v &= ~dd->autoidle_mask;
	v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
	__raw_writel(v, dd->autoidle_reg);

}

/**
 * omap3_dpll_deny_idle - prevent DPLL from automatically idling
 * @clk: struct clk * of the DPLL to operate on
 *
 * Disable DPLL automatic idle control.  No return value.
 */
void omap3_dpll_deny_idle(struct clk *clk)
{
	const struct dpll_data *dd;
	u32 v;

	if (!clk || !clk->dpll_data)
		return;

	dd = clk->dpll_data;

	if (!dd->autoidle_reg) {
		pr_debug("clock: DPLL %s: autoidle not supported\n",
			clk->name);
		return;
	}

	v = __raw_readl(dd->autoidle_reg);
	v &= ~dd->autoidle_mask;
	v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
	__raw_writel(v, dd->autoidle_reg);

}

/* Clock control for DPLL outputs */

/**
 * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
 * @clk: DPLL output struct clk
 *
 * Using parent clock DPLL data, look up DPLL state.  If locked, set our
 * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
 */
unsigned long omap3_clkoutx2_recalc(struct clk *clk)
{
	const struct dpll_data *dd;
	unsigned long rate;
	u32 v;
	struct clk *pclk;

	/* Walk up the parents of clk, looking for a DPLL */
	pclk = clk->parent;
	while (pclk && !pclk->dpll_data)
		pclk = pclk->parent;

	/* clk does not have a DPLL as a parent?  error in the clock data */
	if (!pclk) {
		WARN_ON(1);
		return 0;
	}

	dd = pclk->dpll_data;

	WARN_ON(!dd->enable_mask);

	v = __raw_readl(dd->control_reg) & dd->enable_mask;
	v >>= __ffs(dd->enable_mask);
	if ((v != OMAP3XXX_EN_DPLL_LOCKED) || (dd->flags & DPLL_J_TYPE))
		rate = clk->parent->rate;
	else
		rate = clk->parent->rate * 2;
	return rate;
}

/* OMAP3/4 non-CORE DPLL clkops */

const struct clkops clkops_omap3_noncore_dpll_ops = {
	.enable		= omap3_noncore_dpll_enable,
	.disable	= omap3_noncore_dpll_disable,
	.allow_idle	= omap3_dpll_allow_idle,
	.deny_idle	= omap3_dpll_deny_idle,
};

const struct clkops clkops_omap3_core_dpll_ops = {
	.allow_idle	= omap3_dpll_allow_idle,
	.deny_idle	= omap3_dpll_deny_idle,
};