xref: /openbmc/linux/arch/arm/mach-omap2/clock.c (revision dbab288b)
1 /*
2  *  linux/arch/arm/mach-omap2/clock.c
3  *
4  *  Copyright (C) 2005 Texas Instruments Inc.
5  *  Richard Woodruff <r-woodruff2@ti.com>
6  *  Created for OMAP2.
7  *
8  *  Cleaned up and modified to use omap shared clock framework by
9  *  Tony Lindgren <tony@atomide.com>
10  *
11  *  Based on omap1 clock.c, Copyright (C) 2004 - 2005 Nokia corporation
12  *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License version 2 as
16  * published by the Free Software Foundation.
17  */
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/device.h>
21 #include <linux/list.h>
22 #include <linux/errno.h>
23 #include <linux/delay.h>
24 #include <linux/clk.h>
25 
26 #include <asm/io.h>
27 
28 #include <asm/arch/clock.h>
29 #include <asm/arch/sram.h>
30 
31 #include "prcm-regs.h"
32 #include "memory.h"
33 #include "clock.h"
34 
35 //#define DOWN_VARIABLE_DPLL 1			/* Experimental */
36 
37 static struct prcm_config *curr_prcm_set;
38 static u32 curr_perf_level = PRCM_FULL_SPEED;
39 static struct clk *vclk;
40 static struct clk *sclk;
41 
42 /*-------------------------------------------------------------------------
43  * Omap2 specific clock functions
44  *-------------------------------------------------------------------------*/
45 
46 /* Recalculate SYST_CLK */
47 static void omap2_sys_clk_recalc(struct clk * clk)
48 {
49 	u32 div = PRCM_CLKSRC_CTRL;
50 	div &= (1 << 7) | (1 << 6);	/* Test if ext clk divided by 1 or 2 */
51 	div >>= clk->rate_offset;
52 	clk->rate = (clk->parent->rate / div);
53 	propagate_rate(clk);
54 }
55 
56 static u32 omap2_get_dpll_rate(struct clk * tclk)
57 {
58 	long long dpll_clk;
59 	int dpll_mult, dpll_div, amult;
60 
61 	dpll_mult = (CM_CLKSEL1_PLL >> 12) & 0x03ff;	/* 10 bits */
62 	dpll_div = (CM_CLKSEL1_PLL >> 8) & 0x0f;	/* 4 bits */
63 	dpll_clk = (long long)tclk->parent->rate * dpll_mult;
64 	do_div(dpll_clk, dpll_div + 1);
65 	amult = CM_CLKSEL2_PLL & 0x3;
66 	dpll_clk *= amult;
67 
68 	return dpll_clk;
69 }
70 
71 static void omap2_followparent_recalc(struct clk *clk)
72 {
73 	followparent_recalc(clk);
74 }
75 
76 static void omap2_propagate_rate(struct clk * clk)
77 {
78 	if (!(clk->flags & RATE_FIXED))
79 		clk->rate = clk->parent->rate;
80 
81 	propagate_rate(clk);
82 }
83 
84 /* Enable an APLL if off */
85 static void omap2_clk_fixed_enable(struct clk *clk)
86 {
87 	u32 cval, i=0;
88 
89 	if (clk->enable_bit == 0xff)			/* Parent will do it */
90 		return;
91 
92 	cval = CM_CLKEN_PLL;
93 
94 	if ((cval & (0x3 << clk->enable_bit)) == (0x3 << clk->enable_bit))
95 		return;
96 
97 	cval &= ~(0x3 << clk->enable_bit);
98 	cval |= (0x3 << clk->enable_bit);
99 	CM_CLKEN_PLL = cval;
100 
101 	if (clk == &apll96_ck)
102 		cval = (1 << 8);
103 	else if (clk == &apll54_ck)
104 		cval = (1 << 6);
105 
106 	while (!(CM_IDLEST_CKGEN & cval)) {		/* Wait for lock */
107 		++i;
108 		udelay(1);
109 		if (i == 100000)
110 			break;
111 	}
112 }
113 
114 /* Enables clock without considering parent dependencies or use count
115  * REVISIT: Maybe change this to use clk->enable like on omap1?
116  */
117 static int _omap2_clk_enable(struct clk * clk)
118 {
119 	u32 regval32;
120 
121 	if (clk->flags & ALWAYS_ENABLED)
122 		return 0;
123 
124 	if (unlikely(clk->enable_reg == 0)) {
125 		printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
126 		       clk->name);
127 		return 0;
128 	}
129 
130 	if (clk->enable_reg == (void __iomem *)&CM_CLKEN_PLL) {
131 		omap2_clk_fixed_enable(clk);
132 		return 0;
133 	}
134 
135 	regval32 = __raw_readl(clk->enable_reg);
136 	regval32 |= (1 << clk->enable_bit);
137 	__raw_writel(regval32, clk->enable_reg);
138 
139 	return 0;
140 }
141 
142 /* Stop APLL */
143 static void omap2_clk_fixed_disable(struct clk *clk)
144 {
145 	u32 cval;
146 
147 	if(clk->enable_bit == 0xff)		/* let parent off do it */
148 		return;
149 
150 	cval = CM_CLKEN_PLL;
151 	cval &= ~(0x3 << clk->enable_bit);
152 	CM_CLKEN_PLL = cval;
153 }
154 
155 /* Disables clock without considering parent dependencies or use count */
156 static void _omap2_clk_disable(struct clk *clk)
157 {
158 	u32 regval32;
159 
160 	if (clk->enable_reg == 0)
161 		return;
162 
163 	if (clk->enable_reg == (void __iomem *)&CM_CLKEN_PLL) {
164 		omap2_clk_fixed_disable(clk);
165 		return;
166 	}
167 
168 	regval32 = __raw_readl(clk->enable_reg);
169 	regval32 &= ~(1 << clk->enable_bit);
170 	__raw_writel(regval32, clk->enable_reg);
171 }
172 
173 static int omap2_clk_enable(struct clk *clk)
174 {
175 	int ret = 0;
176 
177 	if (clk->usecount++ == 0) {
178 		if (likely((u32)clk->parent))
179 			ret = omap2_clk_enable(clk->parent);
180 
181 		if (unlikely(ret != 0)) {
182 			clk->usecount--;
183 			return ret;
184 		}
185 
186 		ret = _omap2_clk_enable(clk);
187 
188 		if (unlikely(ret != 0) && clk->parent) {
189 			omap2_clk_disable(clk->parent);
190 			clk->usecount--;
191 		}
192 	}
193 
194 	return ret;
195 }
196 
197 static void omap2_clk_disable(struct clk *clk)
198 {
199 	if (clk->usecount > 0 && !(--clk->usecount)) {
200 		_omap2_clk_disable(clk);
201 		if (likely((u32)clk->parent))
202 			omap2_clk_disable(clk->parent);
203 	}
204 }
205 
206 /*
207  * Uses the current prcm set to tell if a rate is valid.
208  * You can go slower, but not faster within a given rate set.
209  */
210 static u32 omap2_dpll_round_rate(unsigned long target_rate)
211 {
212 	u32 high, low;
213 
214 	if ((CM_CLKSEL2_PLL & 0x3) == 1) {	/* DPLL clockout */
215 		high = curr_prcm_set->dpll_speed * 2;
216 		low = curr_prcm_set->dpll_speed;
217 	} else {				/* DPLL clockout x 2 */
218 		high = curr_prcm_set->dpll_speed;
219 		low = curr_prcm_set->dpll_speed / 2;
220 	}
221 
222 #ifdef DOWN_VARIABLE_DPLL
223 	if (target_rate > high)
224 		return high;
225 	else
226 		return target_rate;
227 #else
228 	if (target_rate > low)
229 		return high;
230 	else
231 		return low;
232 #endif
233 
234 }
235 
236 /*
237  * Used for clocks that are part of CLKSEL_xyz governed clocks.
238  * REVISIT: Maybe change to use clk->enable() functions like on omap1?
239  */
240 static void omap2_clksel_recalc(struct clk * clk)
241 {
242 	u32 fixed = 0, div = 0;
243 
244 	if (clk == &dpll_ck) {
245 		clk->rate = omap2_get_dpll_rate(clk);
246 		fixed = 1;
247 		div = 0;
248 	}
249 
250 	if (clk == &iva1_mpu_int_ifck) {
251 		div = 2;
252 		fixed = 1;
253 	}
254 
255 	if ((clk == &dss1_fck) && ((CM_CLKSEL1_CORE & (0x1f << 8)) == 0)) {
256 		clk->rate = sys_ck.rate;
257 		return;
258 	}
259 
260 	if (!fixed) {
261 		div = omap2_clksel_get_divisor(clk);
262 		if (div == 0)
263 			return;
264 	}
265 
266 	if (div != 0) {
267 		if (unlikely(clk->rate == clk->parent->rate / div))
268 			return;
269 		clk->rate = clk->parent->rate / div;
270 	}
271 
272 	if (unlikely(clk->flags & RATE_PROPAGATES))
273 		propagate_rate(clk);
274 }
275 
276 /*
277  * Finds best divider value in an array based on the source and target
278  * rates. The divider array must be sorted with smallest divider first.
279  */
280 static inline u32 omap2_divider_from_table(u32 size, u32 *div_array,
281 					   u32 src_rate, u32 tgt_rate)
282 {
283 	int i, test_rate;
284 
285 	if (div_array == NULL)
286 		return ~1;
287 
288 	for (i=0; i < size; i++) {
289 		test_rate = src_rate / *div_array;
290 		if (test_rate <= tgt_rate)
291 			return *div_array;
292 		++div_array;
293 	}
294 
295 	return ~0;	/* No acceptable divider */
296 }
297 
298 /*
299  * Find divisor for the given clock and target rate.
300  *
301  * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
302  * they are only settable as part of virtual_prcm set.
303  */
304 static u32 omap2_clksel_round_rate(struct clk *tclk, u32 target_rate,
305 	u32 *new_div)
306 {
307 	u32 gfx_div[] = {2, 3, 4};
308 	u32 sysclkout_div[] = {1, 2, 4, 8, 16};
309 	u32 dss1_div[] = {1, 2, 3, 4, 5, 6, 8, 9, 12, 16};
310 	u32 vylnq_div[] = {1, 2, 3, 4, 6, 8, 9, 12, 16, 18};
311 	u32 best_div = ~0, asize = 0;
312 	u32 *div_array = NULL;
313 
314 	switch (tclk->flags & SRC_RATE_SEL_MASK) {
315 	case CM_GFX_SEL1:
316 		asize = 3;
317 		div_array = gfx_div;
318 		break;
319 	case CM_PLL_SEL1:
320 		return omap2_dpll_round_rate(target_rate);
321 	case CM_SYSCLKOUT_SEL1:
322 		asize = 5;
323 		div_array = sysclkout_div;
324 		break;
325 	case CM_CORE_SEL1:
326 		if(tclk == &dss1_fck){
327 			if(tclk->parent == &core_ck){
328 				asize = 10;
329 				div_array = dss1_div;
330 			} else {
331 				*new_div = 0; /* fixed clk */
332 				return(tclk->parent->rate);
333 			}
334 		} else if((tclk == &vlynq_fck) && cpu_is_omap2420()){
335 			if(tclk->parent == &core_ck){
336 				asize = 10;
337 				div_array = vylnq_div;
338 			} else {
339 				*new_div = 0; /* fixed clk */
340 				return(tclk->parent->rate);
341 			}
342 		}
343 		break;
344 	}
345 
346 	best_div = omap2_divider_from_table(asize, div_array,
347 	 tclk->parent->rate, target_rate);
348 	if (best_div == ~0){
349 		*new_div = 1;
350 		return best_div; /* signal error */
351 	}
352 
353 	*new_div = best_div;
354 	return (tclk->parent->rate / best_div);
355 }
356 
357 /* Given a clock and a rate apply a clock specific rounding function */
358 static long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
359 {
360 	u32 new_div = 0;
361 	int valid_rate;
362 
363 	if (clk->flags & RATE_FIXED)
364 		return clk->rate;
365 
366 	if (clk->flags & RATE_CKCTL) {
367 		valid_rate = omap2_clksel_round_rate(clk, rate, &new_div);
368 		return valid_rate;
369 	}
370 
371 	if (clk->round_rate != 0)
372 		return clk->round_rate(clk, rate);
373 
374 	return clk->rate;
375 }
376 
377 /*
378  * Check the DLL lock state, and return tue if running in unlock mode.
379  * This is needed to compenste for the shifted DLL value in unlock mode.
380  */
381 static u32 omap2_dll_force_needed(void)
382 {
383 	u32 dll_state = SDRC_DLLA_CTRL;		/* dlla and dllb are a set */
384 
385 	if ((dll_state & (1 << 2)) == (1 << 2))
386 		return 1;
387 	else
388 		return 0;
389 }
390 
391 static u32 omap2_reprogram_sdrc(u32 level, u32 force)
392 {
393 	u32 slow_dll_ctrl, fast_dll_ctrl, m_type;
394 	u32 prev = curr_perf_level, flags;
395 
396 	if ((curr_perf_level == level) && !force)
397 		return prev;
398 
399 	m_type = omap2_memory_get_type();
400 	slow_dll_ctrl = omap2_memory_get_slow_dll_ctrl();
401 	fast_dll_ctrl = omap2_memory_get_fast_dll_ctrl();
402 
403 	if (level == PRCM_HALF_SPEED) {
404 		local_irq_save(flags);
405 		PRCM_VOLTSETUP = 0xffff;
406 		omap2_sram_reprogram_sdrc(PRCM_HALF_SPEED,
407 					  slow_dll_ctrl, m_type);
408 		curr_perf_level = PRCM_HALF_SPEED;
409 		local_irq_restore(flags);
410 	}
411 	if (level == PRCM_FULL_SPEED) {
412 		local_irq_save(flags);
413 		PRCM_VOLTSETUP = 0xffff;
414 		omap2_sram_reprogram_sdrc(PRCM_FULL_SPEED,
415 					  fast_dll_ctrl, m_type);
416 		curr_perf_level = PRCM_FULL_SPEED;
417 		local_irq_restore(flags);
418 	}
419 
420 	return prev;
421 }
422 
423 static int omap2_reprogram_dpll(struct clk * clk, unsigned long rate)
424 {
425 	u32 flags, cur_rate, low, mult, div, valid_rate, done_rate;
426 	u32 bypass = 0;
427 	struct prcm_config tmpset;
428 	int ret = -EINVAL;
429 
430 	local_irq_save(flags);
431 	cur_rate = omap2_get_dpll_rate(&dpll_ck);
432 	mult = CM_CLKSEL2_PLL & 0x3;
433 
434 	if ((rate == (cur_rate / 2)) && (mult == 2)) {
435 		omap2_reprogram_sdrc(PRCM_HALF_SPEED, 1);
436 	} else if ((rate == (cur_rate * 2)) && (mult == 1)) {
437 		omap2_reprogram_sdrc(PRCM_FULL_SPEED, 1);
438 	} else if (rate != cur_rate) {
439 		valid_rate = omap2_dpll_round_rate(rate);
440 		if (valid_rate != rate)
441 			goto dpll_exit;
442 
443 		if ((CM_CLKSEL2_PLL & 0x3) == 1)
444 			low = curr_prcm_set->dpll_speed;
445 		else
446 			low = curr_prcm_set->dpll_speed / 2;
447 
448 		tmpset.cm_clksel1_pll = CM_CLKSEL1_PLL;
449 		tmpset.cm_clksel1_pll &= ~(0x3FFF << 8);
450 		div = ((curr_prcm_set->xtal_speed / 1000000) - 1);
451 		tmpset.cm_clksel2_pll = CM_CLKSEL2_PLL;
452 		tmpset.cm_clksel2_pll &= ~0x3;
453 		if (rate > low) {
454 			tmpset.cm_clksel2_pll |= 0x2;
455 			mult = ((rate / 2) / 1000000);
456 			done_rate = PRCM_FULL_SPEED;
457 		} else {
458 			tmpset.cm_clksel2_pll |= 0x1;
459 			mult = (rate / 1000000);
460 			done_rate = PRCM_HALF_SPEED;
461 		}
462 		tmpset.cm_clksel1_pll |= ((div << 8) | (mult << 12));
463 
464 		/* Worst case */
465 		tmpset.base_sdrc_rfr = V24XX_SDRC_RFR_CTRL_BYPASS;
466 
467 		if (rate == curr_prcm_set->xtal_speed)	/* If asking for 1-1 */
468 			bypass = 1;
469 
470 		omap2_reprogram_sdrc(PRCM_FULL_SPEED, 1); /* For init_mem */
471 
472 		/* Force dll lock mode */
473 		omap2_set_prcm(tmpset.cm_clksel1_pll, tmpset.base_sdrc_rfr,
474 			       bypass);
475 
476 		/* Errata: ret dll entry state */
477 		omap2_init_memory_params(omap2_dll_force_needed());
478 		omap2_reprogram_sdrc(done_rate, 0);
479 	}
480 	omap2_clksel_recalc(&dpll_ck);
481 	ret = 0;
482 
483 dpll_exit:
484 	local_irq_restore(flags);
485 	return(ret);
486 }
487 
488 /* Just return the MPU speed */
489 static void omap2_mpu_recalc(struct clk * clk)
490 {
491 	clk->rate = curr_prcm_set->mpu_speed;
492 }
493 
494 /*
495  * Look for a rate equal or less than the target rate given a configuration set.
496  *
497  * What's not entirely clear is "which" field represents the key field.
498  * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
499  * just uses the ARM rates.
500  */
501 static long omap2_round_to_table_rate(struct clk * clk, unsigned long rate)
502 {
503 	struct prcm_config * ptr;
504 	long highest_rate;
505 
506 	if (clk != &virt_prcm_set)
507 		return -EINVAL;
508 
509 	highest_rate = -EINVAL;
510 
511 	for (ptr = rate_table; ptr->mpu_speed; ptr++) {
512 		if (ptr->xtal_speed != sys_ck.rate)
513 			continue;
514 
515 		highest_rate = ptr->mpu_speed;
516 
517 		/* Can check only after xtal frequency check */
518 		if (ptr->mpu_speed <= rate)
519 			break;
520 	}
521 	return highest_rate;
522 }
523 
524 /*
525  * omap2_convert_field_to_div() - turn field value into integer divider
526  */
527 static u32 omap2_clksel_to_divisor(u32 div_sel, u32 field_val)
528 {
529 	u32 i;
530 	u32 clkout_array[] = {1, 2, 4, 8, 16};
531 
532 	if ((div_sel & SRC_RATE_SEL_MASK) == CM_SYSCLKOUT_SEL1) {
533 		for (i = 0; i < 5; i++) {
534 			if (field_val == i)
535 				return clkout_array[i];
536 		}
537 		return ~0;
538 	} else
539 		return field_val;
540 }
541 
542 /*
543  * Returns the CLKSEL divider register value
544  * REVISIT: This should be cleaned up to work nicely with void __iomem *
545  */
546 static u32 omap2_get_clksel(u32 *div_sel, u32 *field_mask,
547 			    struct clk *clk)
548 {
549 	int ret = ~0;
550 	u32 reg_val, div_off;
551 	u32 div_addr = 0;
552 	u32 mask = ~0;
553 
554 	div_off = clk->rate_offset;
555 
556 	switch ((*div_sel & SRC_RATE_SEL_MASK)) {
557 	case CM_MPU_SEL1:
558 		div_addr = (u32)&CM_CLKSEL_MPU;
559 		mask = 0x1f;
560 		break;
561 	case CM_DSP_SEL1:
562 		div_addr = (u32)&CM_CLKSEL_DSP;
563 		if (cpu_is_omap2420()) {
564 			if ((div_off == 0) || (div_off == 8))
565 				mask = 0x1f;
566 			else if (div_off == 5)
567 				mask = 0x3;
568 		} else if (cpu_is_omap2430()) {
569 			if (div_off == 0)
570 				mask = 0x1f;
571 			else if (div_off == 5)
572 				mask = 0x3;
573 		}
574 		break;
575 	case CM_GFX_SEL1:
576 		div_addr = (u32)&CM_CLKSEL_GFX;
577 		if (div_off == 0)
578 			mask = 0x7;
579 		break;
580 	case CM_MODEM_SEL1:
581 		div_addr = (u32)&CM_CLKSEL_MDM;
582 		if (div_off == 0)
583 			mask = 0xf;
584 		break;
585 	case CM_SYSCLKOUT_SEL1:
586 		div_addr = (u32)&PRCM_CLKOUT_CTRL;
587 		if ((div_off == 3) || (div_off = 11))
588 			mask= 0x3;
589 		break;
590 	case CM_CORE_SEL1:
591 		div_addr = (u32)&CM_CLKSEL1_CORE;
592 		switch (div_off) {
593 		case 0:					/* l3 */
594 		case 8:					/* dss1 */
595 		case 15:				/* vylnc-2420 */
596 		case 20:				/* ssi */
597 			mask = 0x1f; break;
598 		case 5:					/* l4 */
599 			mask = 0x3; break;
600 		case 13:				/* dss2 */
601 			mask = 0x1; break;
602 		case 25:				/* usb */
603 			mask = 0x7; break;
604 		}
605 	}
606 
607 	*field_mask = mask;
608 
609 	if (unlikely(mask == ~0))
610 		div_addr = 0;
611 
612 	*div_sel = div_addr;
613 
614 	if (unlikely(div_addr == 0))
615 		return ret;
616 
617 	/* Isolate field */
618 	reg_val = __raw_readl((void __iomem *)div_addr) & (mask << div_off);
619 
620 	/* Normalize back to divider value */
621 	reg_val >>= div_off;
622 
623 	return reg_val;
624 }
625 
626 /*
627  * Return divider to be applied to parent clock.
628  * Return 0 on error.
629  */
630 static u32 omap2_clksel_get_divisor(struct clk *clk)
631 {
632 	int ret = 0;
633 	u32 div, div_sel, div_off, field_mask, field_val;
634 
635 	/* isolate control register */
636 	div_sel = (SRC_RATE_SEL_MASK & clk->flags);
637 
638 	div_off = clk->rate_offset;
639 	field_val = omap2_get_clksel(&div_sel, &field_mask, clk);
640 	if (div_sel == 0)
641 		return ret;
642 
643 	div_sel = (SRC_RATE_SEL_MASK & clk->flags);
644 	div = omap2_clksel_to_divisor(div_sel, field_val);
645 
646 	return div;
647 }
648 
649 /* Set the clock rate for a clock source */
650 static int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
651 
652 {
653 	int ret = -EINVAL;
654 	void __iomem * reg;
655 	u32 div_sel, div_off, field_mask, field_val, reg_val, validrate;
656 	u32 new_div = 0;
657 
658 	if (!(clk->flags & CONFIG_PARTICIPANT) && (clk->flags & RATE_CKCTL)) {
659 		if (clk == &dpll_ck)
660 			return omap2_reprogram_dpll(clk, rate);
661 
662 		/* Isolate control register */
663 		div_sel = (SRC_RATE_SEL_MASK & clk->flags);
664 		div_off = clk->rate_offset;
665 
666 		validrate = omap2_clksel_round_rate(clk, rate, &new_div);
667 		if (validrate != rate)
668 			return(ret);
669 
670 		field_val = omap2_get_clksel(&div_sel, &field_mask, clk);
671 		if (div_sel == 0)
672 			return ret;
673 
674 		if (clk->flags & CM_SYSCLKOUT_SEL1) {
675 			switch (new_div) {
676 			case 16:
677 				field_val = 4;
678 				break;
679 			case 8:
680 				field_val = 3;
681 				break;
682 			case 4:
683 				field_val = 2;
684 				break;
685 			case 2:
686 				field_val = 1;
687 				break;
688 			case 1:
689 				field_val = 0;
690 				break;
691 			}
692 		} else
693 			field_val = new_div;
694 
695 		reg = (void __iomem *)div_sel;
696 
697 		reg_val = __raw_readl(reg);
698 		reg_val &= ~(field_mask << div_off);
699 		reg_val |= (field_val << div_off);
700 
701 		__raw_writel(reg_val, reg);
702 		clk->rate = clk->parent->rate / field_val;
703 
704 		if (clk->flags & DELAYED_APP)
705 			__raw_writel(0x1, (void __iomem *)&PRCM_CLKCFG_CTRL);
706 		ret = 0;
707 	} else if (clk->set_rate != 0)
708 		ret = clk->set_rate(clk, rate);
709 
710 	if (unlikely(ret == 0 && (clk->flags & RATE_PROPAGATES)))
711 		propagate_rate(clk);
712 
713 	return ret;
714 }
715 
716 /* Converts encoded control register address into a full address */
717 static u32 omap2_get_src_field(u32 *type_to_addr, u32 reg_offset,
718 			       struct clk *src_clk, u32 *field_mask)
719 {
720 	u32 val = ~0, src_reg_addr = 0, mask = 0;
721 
722 	/* Find target control register.*/
723 	switch ((*type_to_addr & SRC_RATE_SEL_MASK)) {
724 	case CM_CORE_SEL1:
725 		src_reg_addr = (u32)&CM_CLKSEL1_CORE;
726 		if (reg_offset == 13) {			/* DSS2_fclk */
727 			mask = 0x1;
728 			if (src_clk == &sys_ck)
729 				val = 0;
730 			if (src_clk == &func_48m_ck)
731 				val = 1;
732 		} else if (reg_offset == 8) {		/* DSS1_fclk */
733 			mask = 0x1f;
734 			if (src_clk == &sys_ck)
735 				val = 0;
736 			else if (src_clk == &core_ck)	/* divided clock */
737 				val = 0x10;		/* rate needs fixing */
738 		} else if ((reg_offset == 15) && cpu_is_omap2420()){ /*vlnyq*/
739 			mask = 0x1F;
740 			if(src_clk == &func_96m_ck)
741 				val = 0;
742 			else if (src_clk == &core_ck)
743 				val = 0x10;
744 		}
745 		break;
746 	case CM_CORE_SEL2:
747 		src_reg_addr = (u32)&CM_CLKSEL2_CORE;
748 		mask = 0x3;
749 		if (src_clk == &func_32k_ck)
750 			val = 0x0;
751 		if (src_clk == &sys_ck)
752 			val = 0x1;
753 		if (src_clk == &alt_ck)
754 			val = 0x2;
755 		break;
756 	case CM_WKUP_SEL1:
757 		src_reg_addr = (u32)&CM_CLKSEL_WKUP;
758 		mask = 0x3;
759 		if (src_clk == &func_32k_ck)
760 			val = 0x0;
761 		if (src_clk == &sys_ck)
762 			val = 0x1;
763 		if (src_clk == &alt_ck)
764 			val = 0x2;
765 		break;
766 	case CM_PLL_SEL1:
767 		src_reg_addr = (u32)&CM_CLKSEL1_PLL;
768 		mask = 0x1;
769 		if (reg_offset == 0x3) {
770 			if (src_clk == &apll96_ck)
771 				val = 0;
772 			if (src_clk == &alt_ck)
773 				val = 1;
774 		}
775 		else if (reg_offset == 0x5) {
776 			if (src_clk == &apll54_ck)
777 				val = 0;
778 			if (src_clk == &alt_ck)
779 				val = 1;
780 		}
781 		break;
782 	case CM_PLL_SEL2:
783 		src_reg_addr = (u32)&CM_CLKSEL2_PLL;
784 		mask = 0x3;
785 		if (src_clk == &func_32k_ck)
786 			val = 0x0;
787 		if (src_clk == &dpll_ck)
788 			val = 0x2;
789 		break;
790 	case CM_SYSCLKOUT_SEL1:
791 		src_reg_addr = (u32)&PRCM_CLKOUT_CTRL;
792 		mask = 0x3;
793 		if (src_clk == &dpll_ck)
794 			val = 0;
795 		if (src_clk == &sys_ck)
796 			val = 1;
797 		if (src_clk == &func_96m_ck)
798 			val = 2;
799 		if (src_clk == &func_54m_ck)
800 			val = 3;
801 		break;
802 	}
803 
804 	if (val == ~0)			/* Catch errors in offset */
805 		*type_to_addr = 0;
806 	else
807 		*type_to_addr = src_reg_addr;
808 	*field_mask = mask;
809 
810 	return val;
811 }
812 
813 static int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
814 {
815 	void __iomem * reg;
816 	u32 src_sel, src_off, field_val, field_mask, reg_val, rate;
817 	int ret = -EINVAL;
818 
819 	if (unlikely(clk->flags & CONFIG_PARTICIPANT))
820 		return ret;
821 
822 	if (clk->flags & SRC_SEL_MASK) {	/* On-chip SEL collection */
823 		src_sel = (SRC_RATE_SEL_MASK & clk->flags);
824 		src_off = clk->src_offset;
825 
826 		if (src_sel == 0)
827 			goto set_parent_error;
828 
829 		field_val = omap2_get_src_field(&src_sel, src_off, new_parent,
830 						&field_mask);
831 
832 		reg = (void __iomem *)src_sel;
833 
834 		if (clk->usecount > 0)
835 			_omap2_clk_disable(clk);
836 
837 		/* Set new source value (previous dividers if any in effect) */
838 		reg_val = __raw_readl(reg) & ~(field_mask << src_off);
839 		reg_val |= (field_val << src_off);
840 		__raw_writel(reg_val, reg);
841 
842 		if (clk->flags & DELAYED_APP)
843 			__raw_writel(0x1, (void __iomem *)&PRCM_CLKCFG_CTRL);
844 
845 		if (clk->usecount > 0)
846 			_omap2_clk_enable(clk);
847 
848 		clk->parent = new_parent;
849 
850 		/* SRC_RATE_SEL_MASK clocks follow their parents rates.*/
851 		if ((new_parent == &core_ck) && (clk == &dss1_fck))
852 			clk->rate = new_parent->rate / 0x10;
853 		else
854 			clk->rate = new_parent->rate;
855 
856 		if (unlikely(clk->flags & RATE_PROPAGATES))
857 			propagate_rate(clk);
858 
859 		return 0;
860 	} else {
861 		clk->parent = new_parent;
862 		rate = new_parent->rate;
863 		omap2_clk_set_rate(clk, rate);
864 		ret = 0;
865 	}
866 
867  set_parent_error:
868 	return ret;
869 }
870 
871 /* Sets basic clocks based on the specified rate */
872 static int omap2_select_table_rate(struct clk * clk, unsigned long rate)
873 {
874 	u32 flags, cur_rate, done_rate, bypass = 0;
875 	u8 cpu_mask = 0;
876 	struct prcm_config *prcm;
877 	unsigned long found_speed = 0;
878 
879 	if (clk != &virt_prcm_set)
880 		return -EINVAL;
881 
882 	/* FIXME: Change cpu_is_omap2420() to cpu_is_omap242x() */
883 	if (cpu_is_omap2420())
884 		cpu_mask = RATE_IN_242X;
885 	else if (cpu_is_omap2430())
886 		cpu_mask = RATE_IN_243X;
887 
888 	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
889 		if (!(prcm->flags & cpu_mask))
890 			continue;
891 
892 		if (prcm->xtal_speed != sys_ck.rate)
893 			continue;
894 
895 		if (prcm->mpu_speed <= rate) {
896 			found_speed = prcm->mpu_speed;
897 			break;
898 		}
899 	}
900 
901 	if (!found_speed) {
902 		printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
903 	 rate / 1000000);
904 		return -EINVAL;
905 	}
906 
907 	curr_prcm_set = prcm;
908 	cur_rate = omap2_get_dpll_rate(&dpll_ck);
909 
910 	if (prcm->dpll_speed == cur_rate / 2) {
911 		omap2_reprogram_sdrc(PRCM_HALF_SPEED, 1);
912 	} else if (prcm->dpll_speed == cur_rate * 2) {
913 		omap2_reprogram_sdrc(PRCM_FULL_SPEED, 1);
914 	} else if (prcm->dpll_speed != cur_rate) {
915 		local_irq_save(flags);
916 
917 		if (prcm->dpll_speed == prcm->xtal_speed)
918 			bypass = 1;
919 
920 		if ((prcm->cm_clksel2_pll & 0x3) == 2)
921 			done_rate = PRCM_FULL_SPEED;
922 		else
923 			done_rate = PRCM_HALF_SPEED;
924 
925 		/* MPU divider */
926 		CM_CLKSEL_MPU = prcm->cm_clksel_mpu;
927 
928 		/* dsp + iva1 div(2420), iva2.1(2430) */
929 		CM_CLKSEL_DSP = prcm->cm_clksel_dsp;
930 
931 		CM_CLKSEL_GFX = prcm->cm_clksel_gfx;
932 
933 		/* Major subsystem dividers */
934 		CM_CLKSEL1_CORE = prcm->cm_clksel1_core;
935 		if (cpu_is_omap2430())
936 			CM_CLKSEL_MDM = prcm->cm_clksel_mdm;
937 
938 		/* x2 to enter init_mem */
939 		omap2_reprogram_sdrc(PRCM_FULL_SPEED, 1);
940 
941 		omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
942 			       bypass);
943 
944 		omap2_init_memory_params(omap2_dll_force_needed());
945 		omap2_reprogram_sdrc(done_rate, 0);
946 
947 		local_irq_restore(flags);
948 	}
949 	omap2_clksel_recalc(&dpll_ck);
950 
951 	return 0;
952 }
953 
954 /*-------------------------------------------------------------------------
955  * Omap2 clock reset and init functions
956  *-------------------------------------------------------------------------*/
957 
958 static struct clk_functions omap2_clk_functions = {
959 	.clk_enable		= omap2_clk_enable,
960 	.clk_disable		= omap2_clk_disable,
961 	.clk_round_rate		= omap2_clk_round_rate,
962 	.clk_set_rate		= omap2_clk_set_rate,
963 	.clk_set_parent		= omap2_clk_set_parent,
964 };
965 
966 static void __init omap2_get_crystal_rate(struct clk *osc, struct clk *sys)
967 {
968 	u32 div, aplls, sclk = 13000000;
969 
970 	aplls = CM_CLKSEL1_PLL;
971 	aplls &= ((1 << 23) | (1 << 24) | (1 << 25));
972 	aplls >>= 23;			/* Isolate field, 0,2,3 */
973 
974 	if (aplls == 0)
975 		sclk = 19200000;
976 	else if (aplls == 2)
977 		sclk = 13000000;
978 	else if (aplls == 3)
979 		sclk = 12000000;
980 
981 	div = PRCM_CLKSRC_CTRL;
982 	div &= ((1 << 7) | (1 << 6));
983 	div >>= sys->rate_offset;
984 
985 	osc->rate = sclk * div;
986 	sys->rate = sclk;
987 }
988 
989 /*
990  * Set clocks for bypass mode for reboot to work.
991  */
992 void omap2_clk_prepare_for_reboot(void)
993 {
994 	u32 rate;
995 
996 	if (vclk == NULL || sclk == NULL)
997 		return;
998 
999 	rate = clk_get_rate(sclk);
1000 	clk_set_rate(vclk, rate);
1001 }
1002 
1003 #ifdef CONFIG_OMAP_RESET_CLOCKS
1004 static void __init omap2_disable_unused_clocks(void)
1005 {
1006 	struct clk *ck;
1007 	u32 regval32;
1008 
1009 	list_for_each_entry(ck, &clocks, node) {
1010 		if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
1011 			ck->enable_reg == 0)
1012 			continue;
1013 
1014 		regval32 = __raw_readl(ck->enable_reg);
1015 		if ((regval32 & (1 << ck->enable_bit)) == 0)
1016 			continue;
1017 
1018 		printk(KERN_INFO "Disabling unused clock \"%s\"\n", ck->name);
1019 		_omap2_clk_disable(ck);
1020 	}
1021 }
1022 late_initcall(omap2_disable_unused_clocks);
1023 #endif
1024 
1025 /*
1026  * Switch the MPU rate if specified on cmdline.
1027  * We cannot do this early until cmdline is parsed.
1028  */
1029 static int __init omap2_clk_arch_init(void)
1030 {
1031 	if (!mpurate)
1032 		return -EINVAL;
1033 
1034 	if (omap2_select_table_rate(&virt_prcm_set, mpurate))
1035 		printk(KERN_ERR "Could not find matching MPU rate\n");
1036 
1037 	propagate_rate(&osc_ck);		/* update main root fast */
1038 	propagate_rate(&func_32k_ck);		/* update main root slow */
1039 
1040 	printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL/MPU): "
1041 	       "%ld.%01ld/%ld/%ld MHz\n",
1042 	       (sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
1043 	       (dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;
1044 
1045 	return 0;
1046 }
1047 arch_initcall(omap2_clk_arch_init);
1048 
1049 int __init omap2_clk_init(void)
1050 {
1051 	struct prcm_config *prcm;
1052 	struct clk ** clkp;
1053 	u32 clkrate;
1054 
1055 	clk_init(&omap2_clk_functions);
1056 	omap2_get_crystal_rate(&osc_ck, &sys_ck);
1057 
1058 	for (clkp = onchip_clks; clkp < onchip_clks + ARRAY_SIZE(onchip_clks);
1059 	     clkp++) {
1060 
1061 		if ((*clkp)->flags & CLOCK_IN_OMAP242X && cpu_is_omap2420()) {
1062 			clk_register(*clkp);
1063 			continue;
1064 		}
1065 
1066 		if ((*clkp)->flags & CLOCK_IN_OMAP243X && cpu_is_omap2430()) {
1067 			clk_register(*clkp);
1068 			continue;
1069 		}
1070 	}
1071 
1072 	/* Check the MPU rate set by bootloader */
1073 	clkrate = omap2_get_dpll_rate(&dpll_ck);
1074 	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
1075 		if (prcm->xtal_speed != sys_ck.rate)
1076 			continue;
1077 		if (prcm->dpll_speed <= clkrate)
1078 			 break;
1079 	}
1080 	curr_prcm_set = prcm;
1081 
1082 	propagate_rate(&osc_ck);		/* update main root fast */
1083 	propagate_rate(&func_32k_ck);		/* update main root slow */
1084 
1085 	printk(KERN_INFO "Clocking rate (Crystal/DPLL/MPU): "
1086 	       "%ld.%01ld/%ld/%ld MHz\n",
1087 	       (sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
1088 	       (dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;
1089 
1090 	/*
1091 	 * Only enable those clocks we will need, let the drivers
1092 	 * enable other clocks as necessary
1093 	 */
1094 	clk_enable(&sync_32k_ick);
1095 	clk_enable(&omapctrl_ick);
1096 	if (cpu_is_omap2430())
1097 		clk_enable(&sdrc_ick);
1098 
1099 	/* Avoid sleeping sleeping during omap2_clk_prepare_for_reboot() */
1100 	vclk = clk_get(NULL, "virt_prcm_set");
1101 	sclk = clk_get(NULL, "sys_ck");
1102 
1103 	return 0;
1104 }
1105