xref: /openbmc/linux/arch/arm/mach-omap2/clock.c (revision a37f05ac)
1 /*
2  *  linux/arch/arm/mach-omap2/clock.c
3  *
4  *  Copyright (C) 2005-2008 Texas Instruments, Inc.
5  *  Copyright (C) 2004-2010 Nokia Corporation
6  *
7  *  Contacts:
8  *  Richard Woodruff <r-woodruff2@ti.com>
9  *  Paul Walmsley
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  */
15 #undef DEBUG
16 
17 #include <linux/kernel.h>
18 #include <linux/export.h>
19 #include <linux/list.h>
20 #include <linux/errno.h>
21 #include <linux/err.h>
22 #include <linux/delay.h>
23 #include <linux/clk-provider.h>
24 #include <linux/io.h>
25 #include <linux/bitops.h>
26 #include <linux/clk-private.h>
27 #include <asm/cpu.h>
28 
29 #include <trace/events/power.h>
30 
31 #include "soc.h"
32 #include "clockdomain.h"
33 #include "clock.h"
34 #include "cm.h"
35 #include "cm2xxx.h"
36 #include "cm3xxx.h"
37 #include "cm-regbits-24xx.h"
38 #include "cm-regbits-34xx.h"
39 #include "common.h"
40 
41 /*
42  * MAX_MODULE_ENABLE_WAIT: maximum of number of microseconds to wait
43  * for a module to indicate that it is no longer in idle
44  */
45 #define MAX_MODULE_ENABLE_WAIT		100000
46 
47 u16 cpu_mask;
48 
49 /*
50  * clkdm_control: if true, then when a clock is enabled in the
51  * hardware, its clockdomain will first be enabled; and when a clock
52  * is disabled in the hardware, its clockdomain will be disabled
53  * afterwards.
54  */
55 static bool clkdm_control = true;
56 
57 static LIST_HEAD(clk_hw_omap_clocks);
58 void __iomem *clk_memmaps[CLK_MAX_MEMMAPS];
59 
60 void omap2_clk_writel(u32 val, struct clk_hw_omap *clk, void __iomem *reg)
61 {
62 	if (clk->flags & MEMMAP_ADDRESSING) {
63 		struct clk_omap_reg *r = (struct clk_omap_reg *)&reg;
64 		writel_relaxed(val, clk_memmaps[r->index] + r->offset);
65 	} else {
66 		writel_relaxed(val, reg);
67 	}
68 }
69 
70 u32 omap2_clk_readl(struct clk_hw_omap *clk, void __iomem *reg)
71 {
72 	u32 val;
73 
74 	if (clk->flags & MEMMAP_ADDRESSING) {
75 		struct clk_omap_reg *r = (struct clk_omap_reg *)&reg;
76 		val = readl_relaxed(clk_memmaps[r->index] + r->offset);
77 	} else {
78 		val = readl_relaxed(reg);
79 	}
80 
81 	return val;
82 }
83 
84 /*
85  * OMAP2+ specific clock functions
86  */
87 
88 /* Private functions */
89 
90 
91 /**
92  * _wait_idlest_generic - wait for a module to leave the idle state
93  * @clk: module clock to wait for (needed for register offsets)
94  * @reg: virtual address of module IDLEST register
95  * @mask: value to mask against to determine if the module is active
96  * @idlest: idle state indicator (0 or 1) for the clock
97  * @name: name of the clock (for printk)
98  *
99  * Wait for a module to leave idle, where its idle-status register is
100  * not inside the CM module.  Returns 1 if the module left idle
101  * promptly, or 0 if the module did not leave idle before the timeout
102  * elapsed.  XXX Deprecated - should be moved into drivers for the
103  * individual IP block that the IDLEST register exists in.
104  */
105 static int _wait_idlest_generic(struct clk_hw_omap *clk, void __iomem *reg,
106 				u32 mask, u8 idlest, const char *name)
107 {
108 	int i = 0, ena = 0;
109 
110 	ena = (idlest) ? 0 : mask;
111 
112 	omap_test_timeout(((omap2_clk_readl(clk, reg) & mask) == ena),
113 			  MAX_MODULE_ENABLE_WAIT, i);
114 
115 	if (i < MAX_MODULE_ENABLE_WAIT)
116 		pr_debug("omap clock: module associated with clock %s ready after %d loops\n",
117 			 name, i);
118 	else
119 		pr_err("omap clock: module associated with clock %s didn't enable in %d tries\n",
120 		       name, MAX_MODULE_ENABLE_WAIT);
121 
122 	return (i < MAX_MODULE_ENABLE_WAIT) ? 1 : 0;
123 };
124 
125 /**
126  * _omap2_module_wait_ready - wait for an OMAP module to leave IDLE
127  * @clk: struct clk * belonging to the module
128  *
129  * If the necessary clocks for the OMAP hardware IP block that
130  * corresponds to clock @clk are enabled, then wait for the module to
131  * indicate readiness (i.e., to leave IDLE).  This code does not
132  * belong in the clock code and will be moved in the medium term to
133  * module-dependent code.  No return value.
134  */
135 static void _omap2_module_wait_ready(struct clk_hw_omap *clk)
136 {
137 	void __iomem *companion_reg, *idlest_reg;
138 	u8 other_bit, idlest_bit, idlest_val, idlest_reg_id;
139 	s16 prcm_mod;
140 	int r;
141 
142 	/* Not all modules have multiple clocks that their IDLEST depends on */
143 	if (clk->ops->find_companion) {
144 		clk->ops->find_companion(clk, &companion_reg, &other_bit);
145 		if (!(omap2_clk_readl(clk, companion_reg) & (1 << other_bit)))
146 			return;
147 	}
148 
149 	clk->ops->find_idlest(clk, &idlest_reg, &idlest_bit, &idlest_val);
150 	r = cm_split_idlest_reg(idlest_reg, &prcm_mod, &idlest_reg_id);
151 	if (r) {
152 		/* IDLEST register not in the CM module */
153 		_wait_idlest_generic(clk, idlest_reg, (1 << idlest_bit),
154 				     idlest_val, __clk_get_name(clk->hw.clk));
155 	} else {
156 		cm_wait_module_ready(prcm_mod, idlest_reg_id, idlest_bit);
157 	};
158 }
159 
160 /* Public functions */
161 
162 /**
163  * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
164  * @clk: OMAP clock struct ptr to use
165  *
166  * Convert a clockdomain name stored in a struct clk 'clk' into a
167  * clockdomain pointer, and save it into the struct clk.  Intended to be
168  * called during clk_register().  No return value.
169  */
170 void omap2_init_clk_clkdm(struct clk_hw *hw)
171 {
172 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
173 	struct clockdomain *clkdm;
174 	const char *clk_name;
175 
176 	if (!clk->clkdm_name)
177 		return;
178 
179 	clk_name = __clk_get_name(hw->clk);
180 
181 	clkdm = clkdm_lookup(clk->clkdm_name);
182 	if (clkdm) {
183 		pr_debug("clock: associated clk %s to clkdm %s\n",
184 			 clk_name, clk->clkdm_name);
185 		clk->clkdm = clkdm;
186 	} else {
187 		pr_debug("clock: could not associate clk %s to clkdm %s\n",
188 			 clk_name, clk->clkdm_name);
189 	}
190 }
191 
192 /**
193  * omap2_clk_disable_clkdm_control - disable clkdm control on clk enable/disable
194  *
195  * Prevent the OMAP clock code from calling into the clockdomain code
196  * when a hardware clock in that clockdomain is enabled or disabled.
197  * Intended to be called at init time from omap*_clk_init().  No
198  * return value.
199  */
200 void __init omap2_clk_disable_clkdm_control(void)
201 {
202 	clkdm_control = false;
203 }
204 
205 /**
206  * omap2_clk_dflt_find_companion - find companion clock to @clk
207  * @clk: struct clk * to find the companion clock of
208  * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
209  * @other_bit: u8 ** to return the companion clock bit shift in
210  *
211  * Note: We don't need special code here for INVERT_ENABLE for the
212  * time being since INVERT_ENABLE only applies to clocks enabled by
213  * CM_CLKEN_PLL
214  *
215  * Convert CM_ICLKEN* <-> CM_FCLKEN*.  This conversion assumes it's
216  * just a matter of XORing the bits.
217  *
218  * Some clocks don't have companion clocks.  For example, modules with
219  * only an interface clock (such as MAILBOXES) don't have a companion
220  * clock.  Right now, this code relies on the hardware exporting a bit
221  * in the correct companion register that indicates that the
222  * nonexistent 'companion clock' is active.  Future patches will
223  * associate this type of code with per-module data structures to
224  * avoid this issue, and remove the casts.  No return value.
225  */
226 void omap2_clk_dflt_find_companion(struct clk_hw_omap *clk,
227 			void __iomem **other_reg, u8 *other_bit)
228 {
229 	u32 r;
230 
231 	/*
232 	 * Convert CM_ICLKEN* <-> CM_FCLKEN*.  This conversion assumes
233 	 * it's just a matter of XORing the bits.
234 	 */
235 	r = ((__force u32)clk->enable_reg ^ (CM_FCLKEN ^ CM_ICLKEN));
236 
237 	*other_reg = (__force void __iomem *)r;
238 	*other_bit = clk->enable_bit;
239 }
240 
241 /**
242  * omap2_clk_dflt_find_idlest - find CM_IDLEST reg va, bit shift for @clk
243  * @clk: struct clk * to find IDLEST info for
244  * @idlest_reg: void __iomem ** to return the CM_IDLEST va in
245  * @idlest_bit: u8 * to return the CM_IDLEST bit shift in
246  * @idlest_val: u8 * to return the idle status indicator
247  *
248  * Return the CM_IDLEST register address and bit shift corresponding
249  * to the module that "owns" this clock.  This default code assumes
250  * that the CM_IDLEST bit shift is the CM_*CLKEN bit shift, and that
251  * the IDLEST register address ID corresponds to the CM_*CLKEN
252  * register address ID (e.g., that CM_FCLKEN2 corresponds to
253  * CM_IDLEST2).  This is not true for all modules.  No return value.
254  */
255 void omap2_clk_dflt_find_idlest(struct clk_hw_omap *clk,
256 		void __iomem **idlest_reg, u8 *idlest_bit, u8 *idlest_val)
257 {
258 	u32 r;
259 
260 	r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
261 	*idlest_reg = (__force void __iomem *)r;
262 	*idlest_bit = clk->enable_bit;
263 
264 	/*
265 	 * 24xx uses 0 to indicate not ready, and 1 to indicate ready.
266 	 * 34xx reverses this, just to keep us on our toes
267 	 * AM35xx uses both, depending on the module.
268 	 */
269 	if (cpu_is_omap24xx())
270 		*idlest_val = OMAP24XX_CM_IDLEST_VAL;
271 	else if (cpu_is_omap34xx())
272 		*idlest_val = OMAP34XX_CM_IDLEST_VAL;
273 	else
274 		BUG();
275 
276 }
277 
278 /**
279  * omap2_dflt_clk_enable - enable a clock in the hardware
280  * @hw: struct clk_hw * of the clock to enable
281  *
282  * Enable the clock @hw in the hardware.  We first call into the OMAP
283  * clockdomain code to "enable" the corresponding clockdomain if this
284  * is the first enabled user of the clockdomain.  Then program the
285  * hardware to enable the clock.  Then wait for the IP block that uses
286  * this clock to leave idle (if applicable).  Returns the error value
287  * from clkdm_clk_enable() if it terminated with an error, or -EINVAL
288  * if @hw has a null clock enable_reg, or zero upon success.
289  */
290 int omap2_dflt_clk_enable(struct clk_hw *hw)
291 {
292 	struct clk_hw_omap *clk;
293 	u32 v;
294 	int ret = 0;
295 
296 	clk = to_clk_hw_omap(hw);
297 
298 	if (clkdm_control && clk->clkdm) {
299 		ret = clkdm_clk_enable(clk->clkdm, hw->clk);
300 		if (ret) {
301 			WARN(1, "%s: could not enable %s's clockdomain %s: %d\n",
302 			     __func__, __clk_get_name(hw->clk),
303 			     clk->clkdm->name, ret);
304 			return ret;
305 		}
306 	}
307 
308 	if (unlikely(clk->enable_reg == NULL)) {
309 		pr_err("%s: %s missing enable_reg\n", __func__,
310 		       __clk_get_name(hw->clk));
311 		ret = -EINVAL;
312 		goto err;
313 	}
314 
315 	/* FIXME should not have INVERT_ENABLE bit here */
316 	v = omap2_clk_readl(clk, clk->enable_reg);
317 	if (clk->flags & INVERT_ENABLE)
318 		v &= ~(1 << clk->enable_bit);
319 	else
320 		v |= (1 << clk->enable_bit);
321 	omap2_clk_writel(v, clk, clk->enable_reg);
322 	v = omap2_clk_readl(clk, clk->enable_reg); /* OCP barrier */
323 
324 	if (clk->ops && clk->ops->find_idlest)
325 		_omap2_module_wait_ready(clk);
326 
327 	return 0;
328 
329 err:
330 	if (clkdm_control && clk->clkdm)
331 		clkdm_clk_disable(clk->clkdm, hw->clk);
332 	return ret;
333 }
334 
335 /**
336  * omap2_dflt_clk_disable - disable a clock in the hardware
337  * @hw: struct clk_hw * of the clock to disable
338  *
339  * Disable the clock @hw in the hardware, and call into the OMAP
340  * clockdomain code to "disable" the corresponding clockdomain if all
341  * clocks/hwmods in that clockdomain are now disabled.  No return
342  * value.
343  */
344 void omap2_dflt_clk_disable(struct clk_hw *hw)
345 {
346 	struct clk_hw_omap *clk;
347 	u32 v;
348 
349 	clk = to_clk_hw_omap(hw);
350 	if (!clk->enable_reg) {
351 		/*
352 		 * 'independent' here refers to a clock which is not
353 		 * controlled by its parent.
354 		 */
355 		pr_err("%s: independent clock %s has no enable_reg\n",
356 		       __func__, __clk_get_name(hw->clk));
357 		return;
358 	}
359 
360 	v = omap2_clk_readl(clk, clk->enable_reg);
361 	if (clk->flags & INVERT_ENABLE)
362 		v |= (1 << clk->enable_bit);
363 	else
364 		v &= ~(1 << clk->enable_bit);
365 	omap2_clk_writel(v, clk, clk->enable_reg);
366 	/* No OCP barrier needed here since it is a disable operation */
367 
368 	if (clkdm_control && clk->clkdm)
369 		clkdm_clk_disable(clk->clkdm, hw->clk);
370 }
371 
372 /**
373  * omap2_clkops_enable_clkdm - increment usecount on clkdm of @hw
374  * @hw: struct clk_hw * of the clock being enabled
375  *
376  * Increment the usecount of the clockdomain of the clock pointed to
377  * by @hw; if the usecount is 1, the clockdomain will be "enabled."
378  * Only needed for clocks that don't use omap2_dflt_clk_enable() as
379  * their enable function pointer.  Passes along the return value of
380  * clkdm_clk_enable(), -EINVAL if @hw is not associated with a
381  * clockdomain, or 0 if clock framework-based clockdomain control is
382  * not implemented.
383  */
384 int omap2_clkops_enable_clkdm(struct clk_hw *hw)
385 {
386 	struct clk_hw_omap *clk;
387 	int ret = 0;
388 
389 	clk = to_clk_hw_omap(hw);
390 
391 	if (unlikely(!clk->clkdm)) {
392 		pr_err("%s: %s: no clkdm set ?!\n", __func__,
393 		       __clk_get_name(hw->clk));
394 		return -EINVAL;
395 	}
396 
397 	if (unlikely(clk->enable_reg))
398 		pr_err("%s: %s: should use dflt_clk_enable ?!\n", __func__,
399 		       __clk_get_name(hw->clk));
400 
401 	if (!clkdm_control) {
402 		pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
403 		       __func__, __clk_get_name(hw->clk));
404 		return 0;
405 	}
406 
407 	ret = clkdm_clk_enable(clk->clkdm, hw->clk);
408 	WARN(ret, "%s: could not enable %s's clockdomain %s: %d\n",
409 	     __func__, __clk_get_name(hw->clk), clk->clkdm->name, ret);
410 
411 	return ret;
412 }
413 
414 /**
415  * omap2_clkops_disable_clkdm - decrement usecount on clkdm of @hw
416  * @hw: struct clk_hw * of the clock being disabled
417  *
418  * Decrement the usecount of the clockdomain of the clock pointed to
419  * by @hw; if the usecount is 0, the clockdomain will be "disabled."
420  * Only needed for clocks that don't use omap2_dflt_clk_disable() as their
421  * disable function pointer.  No return value.
422  */
423 void omap2_clkops_disable_clkdm(struct clk_hw *hw)
424 {
425 	struct clk_hw_omap *clk;
426 
427 	clk = to_clk_hw_omap(hw);
428 
429 	if (unlikely(!clk->clkdm)) {
430 		pr_err("%s: %s: no clkdm set ?!\n", __func__,
431 		       __clk_get_name(hw->clk));
432 		return;
433 	}
434 
435 	if (unlikely(clk->enable_reg))
436 		pr_err("%s: %s: should use dflt_clk_disable ?!\n", __func__,
437 		       __clk_get_name(hw->clk));
438 
439 	if (!clkdm_control) {
440 		pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
441 		       __func__, __clk_get_name(hw->clk));
442 		return;
443 	}
444 
445 	clkdm_clk_disable(clk->clkdm, hw->clk);
446 }
447 
448 /**
449  * omap2_dflt_clk_is_enabled - is clock enabled in the hardware?
450  * @hw: struct clk_hw * to check
451  *
452  * Return 1 if the clock represented by @hw is enabled in the
453  * hardware, or 0 otherwise.  Intended for use in the struct
454  * clk_ops.is_enabled function pointer.
455  */
456 int omap2_dflt_clk_is_enabled(struct clk_hw *hw)
457 {
458 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
459 	u32 v;
460 
461 	v = omap2_clk_readl(clk, clk->enable_reg);
462 
463 	if (clk->flags & INVERT_ENABLE)
464 		v ^= BIT(clk->enable_bit);
465 
466 	v &= BIT(clk->enable_bit);
467 
468 	return v ? 1 : 0;
469 }
470 
471 static int __initdata mpurate;
472 
473 /*
474  * By default we use the rate set by the bootloader.
475  * You can override this with mpurate= cmdline option.
476  */
477 static int __init omap_clk_setup(char *str)
478 {
479 	get_option(&str, &mpurate);
480 
481 	if (!mpurate)
482 		return 1;
483 
484 	if (mpurate < 1000)
485 		mpurate *= 1000000;
486 
487 	return 1;
488 }
489 __setup("mpurate=", omap_clk_setup);
490 
491 /**
492  * omap2_init_clk_hw_omap_clocks - initialize an OMAP clock
493  * @clk: struct clk * to initialize
494  *
495  * Add an OMAP clock @clk to the internal list of OMAP clocks.  Used
496  * temporarily for autoidle handling, until this support can be
497  * integrated into the common clock framework code in some way.  No
498  * return value.
499  */
500 void omap2_init_clk_hw_omap_clocks(struct clk *clk)
501 {
502 	struct clk_hw_omap *c;
503 
504 	if (__clk_get_flags(clk) & CLK_IS_BASIC)
505 		return;
506 
507 	c = to_clk_hw_omap(__clk_get_hw(clk));
508 	list_add(&c->node, &clk_hw_omap_clocks);
509 }
510 
511 /**
512  * omap2_clk_enable_autoidle_all - enable autoidle on all OMAP clocks that
513  * support it
514  *
515  * Enable clock autoidle on all OMAP clocks that have allow_idle
516  * function pointers associated with them.  This function is intended
517  * to be temporary until support for this is added to the common clock
518  * code.  Returns 0.
519  */
520 int omap2_clk_enable_autoidle_all(void)
521 {
522 	struct clk_hw_omap *c;
523 
524 	list_for_each_entry(c, &clk_hw_omap_clocks, node)
525 		if (c->ops && c->ops->allow_idle)
526 			c->ops->allow_idle(c);
527 
528 	of_ti_clk_allow_autoidle_all();
529 
530 	return 0;
531 }
532 
533 /**
534  * omap2_clk_disable_autoidle_all - disable autoidle on all OMAP clocks that
535  * support it
536  *
537  * Disable clock autoidle on all OMAP clocks that have allow_idle
538  * function pointers associated with them.  This function is intended
539  * to be temporary until support for this is added to the common clock
540  * code.  Returns 0.
541  */
542 int omap2_clk_disable_autoidle_all(void)
543 {
544 	struct clk_hw_omap *c;
545 
546 	list_for_each_entry(c, &clk_hw_omap_clocks, node)
547 		if (c->ops && c->ops->deny_idle)
548 			c->ops->deny_idle(c);
549 
550 	of_ti_clk_deny_autoidle_all();
551 
552 	return 0;
553 }
554 
555 /**
556  * omap2_clk_deny_idle - disable autoidle on an OMAP clock
557  * @clk: struct clk * to disable autoidle for
558  *
559  * Disable autoidle on an OMAP clock.
560  */
561 int omap2_clk_deny_idle(struct clk *clk)
562 {
563 	struct clk_hw_omap *c;
564 
565 	if (__clk_get_flags(clk) & CLK_IS_BASIC)
566 		return -EINVAL;
567 
568 	c = to_clk_hw_omap(__clk_get_hw(clk));
569 	if (c->ops && c->ops->deny_idle)
570 		c->ops->deny_idle(c);
571 	return 0;
572 }
573 
574 /**
575  * omap2_clk_allow_idle - enable autoidle on an OMAP clock
576  * @clk: struct clk * to enable autoidle for
577  *
578  * Enable autoidle on an OMAP clock.
579  */
580 int omap2_clk_allow_idle(struct clk *clk)
581 {
582 	struct clk_hw_omap *c;
583 
584 	if (__clk_get_flags(clk) & CLK_IS_BASIC)
585 		return -EINVAL;
586 
587 	c = to_clk_hw_omap(__clk_get_hw(clk));
588 	if (c->ops && c->ops->allow_idle)
589 		c->ops->allow_idle(c);
590 	return 0;
591 }
592 
593 /**
594  * omap2_clk_enable_init_clocks - prepare & enable a list of clocks
595  * @clk_names: ptr to an array of strings of clock names to enable
596  * @num_clocks: number of clock names in @clk_names
597  *
598  * Prepare and enable a list of clocks, named by @clk_names.  No
599  * return value. XXX Deprecated; only needed until these clocks are
600  * properly claimed and enabled by the drivers or core code that uses
601  * them.  XXX What code disables & calls clk_put on these clocks?
602  */
603 void omap2_clk_enable_init_clocks(const char **clk_names, u8 num_clocks)
604 {
605 	struct clk *init_clk;
606 	int i;
607 
608 	for (i = 0; i < num_clocks; i++) {
609 		init_clk = clk_get(NULL, clk_names[i]);
610 		clk_prepare_enable(init_clk);
611 	}
612 }
613 
614 const struct clk_hw_omap_ops clkhwops_wait = {
615 	.find_idlest	= omap2_clk_dflt_find_idlest,
616 	.find_companion	= omap2_clk_dflt_find_companion,
617 };
618 
619 /**
620  * omap_clocks_register - register an array of omap_clk
621  * @ocs: pointer to an array of omap_clk to register
622  */
623 void __init omap_clocks_register(struct omap_clk oclks[], int cnt)
624 {
625 	struct omap_clk *c;
626 
627 	for (c = oclks; c < oclks + cnt; c++) {
628 		clkdev_add(&c->lk);
629 		if (!__clk_init(NULL, c->lk.clk))
630 			omap2_init_clk_hw_omap_clocks(c->lk.clk);
631 	}
632 }
633 
634 /**
635  * omap2_clk_switch_mpurate_at_boot - switch ARM MPU rate by boot-time argument
636  * @mpurate_ck_name: clk name of the clock to change rate
637  *
638  * Change the ARM MPU clock rate to the rate specified on the command
639  * line, if one was specified.  @mpurate_ck_name should be
640  * "virt_prcm_set" on OMAP2xxx and "dpll1_ck" on OMAP34xx/OMAP36xx.
641  * XXX Does not handle voltage scaling - on OMAP2xxx this is currently
642  * handled by the virt_prcm_set clock, but this should be handled by
643  * the OPP layer.  XXX This is intended to be handled by the OPP layer
644  * code in the near future and should be removed from the clock code.
645  * Returns -EINVAL if 'mpurate' is zero or if clk_set_rate() rejects
646  * the rate, -ENOENT if the struct clk referred to by @mpurate_ck_name
647  * cannot be found, or 0 upon success.
648  */
649 int __init omap2_clk_switch_mpurate_at_boot(const char *mpurate_ck_name)
650 {
651 	struct clk *mpurate_ck;
652 	int r;
653 
654 	if (!mpurate)
655 		return -EINVAL;
656 
657 	mpurate_ck = clk_get(NULL, mpurate_ck_name);
658 	if (WARN(IS_ERR(mpurate_ck), "Failed to get %s.\n", mpurate_ck_name))
659 		return -ENOENT;
660 
661 	r = clk_set_rate(mpurate_ck, mpurate);
662 	if (r < 0) {
663 		WARN(1, "clock: %s: unable to set MPU rate to %d: %d\n",
664 		     mpurate_ck_name, mpurate, r);
665 		clk_put(mpurate_ck);
666 		return -EINVAL;
667 	}
668 
669 	calibrate_delay();
670 	clk_put(mpurate_ck);
671 
672 	return 0;
673 }
674 
675 /**
676  * omap2_clk_print_new_rates - print summary of current clock tree rates
677  * @hfclkin_ck_name: clk name for the off-chip HF oscillator
678  * @core_ck_name: clk name for the on-chip CORE_CLK
679  * @mpu_ck_name: clk name for the ARM MPU clock
680  *
681  * Prints a short message to the console with the HFCLKIN oscillator
682  * rate, the rate of the CORE clock, and the rate of the ARM MPU clock.
683  * Called by the boot-time MPU rate switching code.   XXX This is intended
684  * to be handled by the OPP layer code in the near future and should be
685  * removed from the clock code.  No return value.
686  */
687 void __init omap2_clk_print_new_rates(const char *hfclkin_ck_name,
688 				      const char *core_ck_name,
689 				      const char *mpu_ck_name)
690 {
691 	struct clk *hfclkin_ck, *core_ck, *mpu_ck;
692 	unsigned long hfclkin_rate;
693 
694 	mpu_ck = clk_get(NULL, mpu_ck_name);
695 	if (WARN(IS_ERR(mpu_ck), "clock: failed to get %s.\n", mpu_ck_name))
696 		return;
697 
698 	core_ck = clk_get(NULL, core_ck_name);
699 	if (WARN(IS_ERR(core_ck), "clock: failed to get %s.\n", core_ck_name))
700 		return;
701 
702 	hfclkin_ck = clk_get(NULL, hfclkin_ck_name);
703 	if (WARN(IS_ERR(hfclkin_ck), "Failed to get %s.\n", hfclkin_ck_name))
704 		return;
705 
706 	hfclkin_rate = clk_get_rate(hfclkin_ck);
707 
708 	pr_info("Switched to new clocking rate (Crystal/Core/MPU): %ld.%01ld/%ld/%ld MHz\n",
709 		(hfclkin_rate / 1000000), ((hfclkin_rate / 100000) % 10),
710 		(clk_get_rate(core_ck) / 1000000),
711 		(clk_get_rate(mpu_ck) / 1000000));
712 }
713