summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap2/clock24xx.c
blob: ece32d8acba45f86328709681fba7a32f6f9c20f (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
/*
 *  linux/arch/arm/mach-omap2/clock.c
 *
 *  Copyright (C) 2005-2008 Texas Instruments, Inc.
 *  Copyright (C) 2004-2008 Nokia Corporation
 *
 *  Contacts:
 *  Richard Woodruff <r-woodruff2@ti.com>
 *  Paul Walmsley
 *
 *  Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
 *  Gordon McNutt and RidgeRun, 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.
 */
#undef DEBUG

#include <linux/module.h>
#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/cpufreq.h>

#include <asm/arch/clock.h>
#include <asm/arch/sram.h>
#include <asm/div64.h>
#include <asm/bitops.h>

#include "memory.h"
#include "clock.h"
#include "clock24xx.h"
#include "prm.h"
#include "prm-regbits-24xx.h"
#include "cm.h"
#include "cm-regbits-24xx.h"

/* CM_CLKEN_PLL.EN_{54,96}M_PLL options (24XX) */
#define EN_APLL_STOPPED			0
#define EN_APLL_LOCKED			3

/* CM_CLKSEL1_PLL.APLLS_CLKIN options (24XX) */
#define APLLS_CLKIN_19_2MHZ		0
#define APLLS_CLKIN_13MHZ		2
#define APLLS_CLKIN_12MHZ		3

/* #define DOWN_VARIABLE_DPLL 1 */		/* Experimental */

static struct prcm_config *curr_prcm_set;
static struct clk *vclk;
static struct clk *sclk;

/*-------------------------------------------------------------------------
 * Omap24xx specific clock functions
 *-------------------------------------------------------------------------*/

/* This actually returns the rate of core_ck, not dpll_ck. */
static u32 omap2_get_dpll_rate_24xx(struct clk *tclk)
{
	long long dpll_clk;
	u8 amult;

	dpll_clk = omap2_get_dpll_rate(tclk);

	amult = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
	amult &= OMAP24XX_CORE_CLK_SRC_MASK;
	dpll_clk *= amult;

	return dpll_clk;
}

static int omap2_enable_osc_ck(struct clk *clk)
{
	u32 pcc;

	pcc = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);

	__raw_writel(pcc & ~OMAP_AUTOEXTCLKMODE_MASK,
		      OMAP24XX_PRCM_CLKSRC_CTRL);

	return 0;
}

static void omap2_disable_osc_ck(struct clk *clk)
{
	u32 pcc;

	pcc = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);

	__raw_writel(pcc | OMAP_AUTOEXTCLKMODE_MASK,
		      OMAP24XX_PRCM_CLKSRC_CTRL);
}

#ifdef OLD_CK
/* Recalculate SYST_CLK */
static void omap2_sys_clk_recalc(struct clk * clk)
{
	u32 div = PRCM_CLKSRC_CTRL;
	div &= (1 << 7) | (1 << 6);	/* Test if ext clk divided by 1 or 2 */
	div >>= clk->rate_offset;
	clk->rate = (clk->parent->rate / div);
	propagate_rate(clk);
}
#endif	/* OLD_CK */

/* Enable an APLL if off */
static int omap2_clk_fixed_enable(struct clk *clk)
{
	u32 cval, apll_mask;

	apll_mask = EN_APLL_LOCKED << clk->enable_bit;

	cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);

	if ((cval & apll_mask) == apll_mask)
		return 0;   /* apll already enabled */

	cval &= ~apll_mask;
	cval |= apll_mask;
	cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);

	if (clk == &apll96_ck)
		cval = OMAP24XX_ST_96M_APLL;
	else if (clk == &apll54_ck)
		cval = OMAP24XX_ST_54M_APLL;

	omap2_wait_clock_ready(OMAP_CM_REGADDR(PLL_MOD, CM_IDLEST), cval,
			    clk->name);

	/*
	 * REVISIT: Should we return an error code if omap2_wait_clock_ready()
	 * fails?
	 */
	return 0;
}

/* Stop APLL */
static void omap2_clk_fixed_disable(struct clk *clk)
{
	u32 cval;

	cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
	cval &= ~(EN_APLL_LOCKED << clk->enable_bit);
	cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
}

/*
 * Uses the current prcm set to tell if a rate is valid.
 * You can go slower, but not faster within a given rate set.
 */
static u32 omap2_dpll_round_rate(unsigned long target_rate)
{
	u32 high, low, core_clk_src;

	core_clk_src = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
	core_clk_src &= OMAP24XX_CORE_CLK_SRC_MASK;

	if (core_clk_src == CORE_CLK_SRC_DPLL) {	/* DPLL clockout */
		high = curr_prcm_set->dpll_speed * 2;
		low = curr_prcm_set->dpll_speed;
	} else {				/* DPLL clockout x 2 */
		high = curr_prcm_set->dpll_speed;
		low = curr_prcm_set->dpll_speed / 2;
	}

#ifdef DOWN_VARIABLE_DPLL
	if (target_rate > high)
		return high;
	else
		return target_rate;
#else
	if (target_rate > low)
		return high;
	else
		return low;
#endif

}

static void omap2_dpll_recalc(struct clk *clk)
{
	clk->rate = omap2_get_dpll_rate_24xx(clk);

	propagate_rate(clk);
}

static int omap2_reprogram_dpll(struct clk *clk, unsigned long rate)
{
	u32 cur_rate, low, mult, div, valid_rate, done_rate;
	u32 bypass = 0;
	struct prcm_config tmpset;
	const struct dpll_data *dd;
	unsigned long flags;
	int ret = -EINVAL;

	local_irq_save(flags);
	cur_rate = omap2_get_dpll_rate_24xx(&dpll_ck);
	mult = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
	mult &= OMAP24XX_CORE_CLK_SRC_MASK;

	if ((rate == (cur_rate / 2)) && (mult == 2)) {
		omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL, 1);
	} else if ((rate == (cur_rate * 2)) && (mult == 1)) {
		omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1);
	} else if (rate != cur_rate) {
		valid_rate = omap2_dpll_round_rate(rate);
		if (valid_rate != rate)
			goto dpll_exit;

		if (mult == 1)
			low = curr_prcm_set->dpll_speed;
		else
			low = curr_prcm_set->dpll_speed / 2;

		dd = clk->dpll_data;
		if (!dd)
			goto dpll_exit;

		tmpset.cm_clksel1_pll = __raw_readl(dd->mult_div1_reg);
		tmpset.cm_clksel1_pll &= ~(dd->mult_mask |
					   dd->div1_mask);
		div = ((curr_prcm_set->xtal_speed / 1000000) - 1);
		tmpset.cm_clksel2_pll = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
		tmpset.cm_clksel2_pll &= ~OMAP24XX_CORE_CLK_SRC_MASK;
		if (rate > low) {
			tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL_X2;
			mult = ((rate / 2) / 1000000);
			done_rate = CORE_CLK_SRC_DPLL_X2;
		} else {
			tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL;
			mult = (rate / 1000000);
			done_rate = CORE_CLK_SRC_DPLL;
		}
		tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask));
		tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask));

		/* Worst case */
		tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS;

		if (rate == curr_prcm_set->xtal_speed)	/* If asking for 1-1 */
			bypass = 1;

		omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1); /* For init_mem */

		/* Force dll lock mode */
		omap2_set_prcm(tmpset.cm_clksel1_pll, tmpset.base_sdrc_rfr,
			       bypass);

		/* Errata: ret dll entry state */
		omap2_init_memory_params(omap2_dll_force_needed());
		omap2_reprogram_sdrc(done_rate, 0);
	}
	omap2_dpll_recalc(&dpll_ck);
	ret = 0;

dpll_exit:
	local_irq_restore(flags);
	return(ret);
}

/**
 * omap2_table_mpu_recalc - just return the MPU speed
 * @clk: virt_prcm_set struct clk
 *
 * Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
 */
static void omap2_table_mpu_recalc(struct clk *clk)
{
	clk->rate = curr_prcm_set->mpu_speed;
}

/*
 * Look for a rate equal or less than the target rate given a configuration set.
 *
 * What's not entirely clear is "which" field represents the key field.
 * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
 * just uses the ARM rates.
 */
static long omap2_round_to_table_rate(struct clk *clk, unsigned long rate)
{
	struct prcm_config *ptr;
	long highest_rate;

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

	highest_rate = -EINVAL;

	for (ptr = rate_table; ptr->mpu_speed; ptr++) {
		if (!(ptr->flags & cpu_mask))
			continue;
		if (ptr->xtal_speed != sys_ck.rate)
			continue;

		highest_rate = ptr->mpu_speed;

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

/* Sets basic clocks based on the specified rate */
static int omap2_select_table_rate(struct clk *clk, unsigned long rate)
{
	u32 cur_rate, done_rate, bypass = 0, tmp;
	struct prcm_config *prcm;
	unsigned long found_speed = 0;
	unsigned long flags;

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

	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
		if (!(prcm->flags & cpu_mask))
			continue;

		if (prcm->xtal_speed != sys_ck.rate)
			continue;

		if (prcm->mpu_speed <= rate) {
			found_speed = prcm->mpu_speed;
			break;
		}
	}

	if (!found_speed) {
		printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
		       rate / 1000000);
		return -EINVAL;
	}

	curr_prcm_set = prcm;
	cur_rate = omap2_get_dpll_rate_24xx(&dpll_ck);

	if (prcm->dpll_speed == cur_rate / 2) {
		omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL, 1);
	} else if (prcm->dpll_speed == cur_rate * 2) {
		omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1);
	} else if (prcm->dpll_speed != cur_rate) {
		local_irq_save(flags);

		if (prcm->dpll_speed == prcm->xtal_speed)
			bypass = 1;

		if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
		    CORE_CLK_SRC_DPLL_X2)
			done_rate = CORE_CLK_SRC_DPLL_X2;
		else
			done_rate = CORE_CLK_SRC_DPLL;

		/* MPU divider */
		cm_write_mod_reg(prcm->cm_clksel_mpu, MPU_MOD, CM_CLKSEL);

		/* dsp + iva1 div(2420), iva2.1(2430) */
		cm_write_mod_reg(prcm->cm_clksel_dsp,
				 OMAP24XX_DSP_MOD, CM_CLKSEL);

		cm_write_mod_reg(prcm->cm_clksel_gfx, GFX_MOD, CM_CLKSEL);

		/* Major subsystem dividers */
		tmp = cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) & OMAP24XX_CLKSEL_DSS2_MASK;
		cm_write_mod_reg(prcm->cm_clksel1_core | tmp, CORE_MOD, CM_CLKSEL1);
		if (cpu_is_omap2430())
			cm_write_mod_reg(prcm->cm_clksel_mdm,
					 OMAP2430_MDM_MOD, CM_CLKSEL);

		/* x2 to enter init_mem */
		omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1);

		omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
			       bypass);

		omap2_init_memory_params(omap2_dll_force_needed());
		omap2_reprogram_sdrc(done_rate, 0);

		local_irq_restore(flags);
	}
	omap2_dpll_recalc(&dpll_ck);

	return 0;
}

static struct clk_functions omap2_clk_functions = {
	.clk_enable		= omap2_clk_enable,
	.clk_disable		= omap2_clk_disable,
	.clk_round_rate		= omap2_clk_round_rate,
	.clk_set_rate		= omap2_clk_set_rate,
	.clk_set_parent		= omap2_clk_set_parent,
	.clk_disable_unused	= omap2_clk_disable_unused,
};

static u32 omap2_get_apll_clkin(void)
{
	u32 aplls, sclk = 0;

	aplls = cm_read_mod_reg(PLL_MOD, CM_CLKSEL1);
	aplls &= OMAP24XX_APLLS_CLKIN_MASK;
	aplls >>= OMAP24XX_APLLS_CLKIN_SHIFT;

	if (aplls == APLLS_CLKIN_19_2MHZ)
		sclk = 19200000;
	else if (aplls == APLLS_CLKIN_13MHZ)
		sclk = 13000000;
	else if (aplls == APLLS_CLKIN_12MHZ)
		sclk = 12000000;

	return sclk;
}

static u32 omap2_get_sysclkdiv(void)
{
	u32 div;

	div = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);
	div &= OMAP_SYSCLKDIV_MASK;
	div >>= OMAP_SYSCLKDIV_SHIFT;

	return div;
}

static void omap2_osc_clk_recalc(struct clk *clk)
{
	clk->rate = omap2_get_apll_clkin() * omap2_get_sysclkdiv();
	propagate_rate(clk);
}

static void omap2_sys_clk_recalc(struct clk *clk)
{
	clk->rate = clk->parent->rate / omap2_get_sysclkdiv();
	propagate_rate(clk);
}

/*
 * Set clocks for bypass mode for reboot to work.
 */
void omap2_clk_prepare_for_reboot(void)
{
	u32 rate;

	if (vclk == NULL || sclk == NULL)
		return;

	rate = clk_get_rate(sclk);
	clk_set_rate(vclk, rate);
}

/*
 * Switch the MPU rate if specified on cmdline.
 * We cannot do this early until cmdline is parsed.
 */
static int __init omap2_clk_arch_init(void)
{
	if (!mpurate)
		return -EINVAL;

	if (omap2_select_table_rate(&virt_prcm_set, mpurate))
		printk(KERN_ERR "Could not find matching MPU rate\n");

	recalculate_root_clocks();

	printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL/MPU): "
	       "%ld.%01ld/%ld/%ld MHz\n",
	       (sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
	       (dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;

	return 0;
}
arch_initcall(omap2_clk_arch_init);

int __init omap2_clk_init(void)
{
	struct prcm_config *prcm;
	struct clk **clkp;
	u32 clkrate;

	if (cpu_is_omap242x())
		cpu_mask = RATE_IN_242X;
	else if (cpu_is_omap2430())
		cpu_mask = RATE_IN_243X;

	clk_init(&omap2_clk_functions);

	omap2_osc_clk_recalc(&osc_ck);
	omap2_sys_clk_recalc(&sys_ck);

	for (clkp = onchip_24xx_clks;
	     clkp < onchip_24xx_clks + ARRAY_SIZE(onchip_24xx_clks);
	     clkp++) {

		if ((*clkp)->flags & CLOCK_IN_OMAP242X && cpu_is_omap2420()) {
			clk_register(*clkp);
			continue;
		}

		if ((*clkp)->flags & CLOCK_IN_OMAP243X && cpu_is_omap2430()) {
			clk_register(*clkp);
			continue;
		}
	}

	/* Check the MPU rate set by bootloader */
	clkrate = omap2_get_dpll_rate_24xx(&dpll_ck);
	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
		if (!(prcm->flags & cpu_mask))
			continue;
		if (prcm->xtal_speed != sys_ck.rate)
			continue;
		if (prcm->dpll_speed <= clkrate)
			 break;
	}
	curr_prcm_set = prcm;

	recalculate_root_clocks();

	printk(KERN_INFO "Clocking rate (Crystal/DPLL/MPU): "
	       "%ld.%01ld/%ld/%ld MHz\n",
	       (sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
	       (dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;

	/*
	 * Only enable those clocks we will need, let the drivers
	 * enable other clocks as necessary
	 */
	clk_enable_init_clocks();

	/* Avoid sleeping sleeping during omap2_clk_prepare_for_reboot() */
	vclk = clk_get(NULL, "virt_prcm_set");
	sclk = clk_get(NULL, "sys_ck");

	return 0;
}