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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/list.h>
19 #include <linux/errno.h>
20 #include <linux/err.h>
21 #include <linux/delay.h>
22 #include <linux/clk.h>
23 #include <linux/io.h>
24 #include <linux/bitops.h>
25 #include <trace/events/power.h>
26 
27 #include <asm/cpu.h>
28 #include <plat/clock.h>
29 #include "clockdomain.h"
30 #include <plat/cpu.h>
31 #include <plat/prcm.h>
32 
33 #include "clock.h"
34 #include "cm2xxx_3xxx.h"
35 #include "cm-regbits-24xx.h"
36 #include "cm-regbits-34xx.h"
37 
38 u16 cpu_mask;
39 
40 /*
41  * clkdm_control: if true, then when a clock is enabled in the
42  * hardware, its clockdomain will first be enabled; and when a clock
43  * is disabled in the hardware, its clockdomain will be disabled
44  * afterwards.
45  */
46 static bool clkdm_control = true;
47 
48 /*
49  * OMAP2+ specific clock functions
50  */
51 
52 /* Private functions */
53 
54 /**
55  * _omap2_module_wait_ready - wait for an OMAP module to leave IDLE
56  * @clk: struct clk * belonging to the module
57  *
58  * If the necessary clocks for the OMAP hardware IP block that
59  * corresponds to clock @clk are enabled, then wait for the module to
60  * indicate readiness (i.e., to leave IDLE).  This code does not
61  * belong in the clock code and will be moved in the medium term to
62  * module-dependent code.  No return value.
63  */
_omap2_module_wait_ready(struct clk * clk)64 static void _omap2_module_wait_ready(struct clk *clk)
65 {
66 	void __iomem *companion_reg, *idlest_reg;
67 	u8 other_bit, idlest_bit, idlest_val;
68 
69 	/* Not all modules have multiple clocks that their IDLEST depends on */
70 	if (clk->ops->find_companion) {
71 		clk->ops->find_companion(clk, &companion_reg, &other_bit);
72 		if (!(__raw_readl(companion_reg) & (1 << other_bit)))
73 			return;
74 	}
75 
76 	clk->ops->find_idlest(clk, &idlest_reg, &idlest_bit, &idlest_val);
77 
78 	omap2_cm_wait_idlest(idlest_reg, (1 << idlest_bit), idlest_val,
79 			     clk->name);
80 }
81 
82 /* Public functions */
83 
84 /**
85  * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
86  * @clk: OMAP clock struct ptr to use
87  *
88  * Convert a clockdomain name stored in a struct clk 'clk' into a
89  * clockdomain pointer, and save it into the struct clk.  Intended to be
90  * called during clk_register().  No return value.
91  */
omap2_init_clk_clkdm(struct clk * clk)92 void omap2_init_clk_clkdm(struct clk *clk)
93 {
94 	struct clockdomain *clkdm;
95 
96 	if (!clk->clkdm_name)
97 		return;
98 
99 	clkdm = clkdm_lookup(clk->clkdm_name);
100 	if (clkdm) {
101 		pr_debug("clock: associated clk %s to clkdm %s\n",
102 			 clk->name, clk->clkdm_name);
103 		clk->clkdm = clkdm;
104 	} else {
105 		pr_debug("clock: could not associate clk %s to "
106 			 "clkdm %s\n", clk->name, clk->clkdm_name);
107 	}
108 }
109 
110 /**
111  * omap2_clk_disable_clkdm_control - disable clkdm control on clk enable/disable
112  *
113  * Prevent the OMAP clock code from calling into the clockdomain code
114  * when a hardware clock in that clockdomain is enabled or disabled.
115  * Intended to be called at init time from omap*_clk_init().  No
116  * return value.
117  */
omap2_clk_disable_clkdm_control(void)118 void __init omap2_clk_disable_clkdm_control(void)
119 {
120 	clkdm_control = false;
121 }
122 
123 /**
124  * omap2_clk_dflt_find_companion - find companion clock to @clk
125  * @clk: struct clk * to find the companion clock of
126  * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
127  * @other_bit: u8 ** to return the companion clock bit shift in
128  *
129  * Note: We don't need special code here for INVERT_ENABLE for the
130  * time being since INVERT_ENABLE only applies to clocks enabled by
131  * CM_CLKEN_PLL
132  *
133  * Convert CM_ICLKEN* <-> CM_FCLKEN*.  This conversion assumes it's
134  * just a matter of XORing the bits.
135  *
136  * Some clocks don't have companion clocks.  For example, modules with
137  * only an interface clock (such as MAILBOXES) don't have a companion
138  * clock.  Right now, this code relies on the hardware exporting a bit
139  * in the correct companion register that indicates that the
140  * nonexistent 'companion clock' is active.  Future patches will
141  * associate this type of code with per-module data structures to
142  * avoid this issue, and remove the casts.  No return value.
143  */
omap2_clk_dflt_find_companion(struct clk * clk,void __iomem ** other_reg,u8 * other_bit)144 void omap2_clk_dflt_find_companion(struct clk *clk, void __iomem **other_reg,
145 				   u8 *other_bit)
146 {
147 	u32 r;
148 
149 	/*
150 	 * Convert CM_ICLKEN* <-> CM_FCLKEN*.  This conversion assumes
151 	 * it's just a matter of XORing the bits.
152 	 */
153 	r = ((__force u32)clk->enable_reg ^ (CM_FCLKEN ^ CM_ICLKEN));
154 
155 	*other_reg = (__force void __iomem *)r;
156 	*other_bit = clk->enable_bit;
157 }
158 
159 /**
160  * omap2_clk_dflt_find_idlest - find CM_IDLEST reg va, bit shift for @clk
161  * @clk: struct clk * to find IDLEST info for
162  * @idlest_reg: void __iomem ** to return the CM_IDLEST va in
163  * @idlest_bit: u8 * to return the CM_IDLEST bit shift in
164  * @idlest_val: u8 * to return the idle status indicator
165  *
166  * Return the CM_IDLEST register address and bit shift corresponding
167  * to the module that "owns" this clock.  This default code assumes
168  * that the CM_IDLEST bit shift is the CM_*CLKEN bit shift, and that
169  * the IDLEST register address ID corresponds to the CM_*CLKEN
170  * register address ID (e.g., that CM_FCLKEN2 corresponds to
171  * CM_IDLEST2).  This is not true for all modules.  No return value.
172  */
omap2_clk_dflt_find_idlest(struct clk * clk,void __iomem ** idlest_reg,u8 * idlest_bit,u8 * idlest_val)173 void omap2_clk_dflt_find_idlest(struct clk *clk, void __iomem **idlest_reg,
174 				u8 *idlest_bit, u8 *idlest_val)
175 {
176 	u32 r;
177 
178 	r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
179 	*idlest_reg = (__force void __iomem *)r;
180 	*idlest_bit = clk->enable_bit;
181 
182 	/*
183 	 * 24xx uses 0 to indicate not ready, and 1 to indicate ready.
184 	 * 34xx reverses this, just to keep us on our toes
185 	 * AM35xx uses both, depending on the module.
186 	 */
187 	if (cpu_is_omap24xx())
188 		*idlest_val = OMAP24XX_CM_IDLEST_VAL;
189 	else if (cpu_is_omap34xx())
190 		*idlest_val = OMAP34XX_CM_IDLEST_VAL;
191 	else
192 		BUG();
193 
194 }
195 
omap2_dflt_clk_enable(struct clk * clk)196 int omap2_dflt_clk_enable(struct clk *clk)
197 {
198 	u32 v;
199 
200 	if (unlikely(clk->enable_reg == NULL)) {
201 		pr_err("clock.c: Enable for %s without enable code\n",
202 		       clk->name);
203 		return 0; /* REVISIT: -EINVAL */
204 	}
205 
206 	v = __raw_readl(clk->enable_reg);
207 	if (clk->flags & INVERT_ENABLE)
208 		v &= ~(1 << clk->enable_bit);
209 	else
210 		v |= (1 << clk->enable_bit);
211 	__raw_writel(v, clk->enable_reg);
212 	v = __raw_readl(clk->enable_reg); /* OCP barrier */
213 
214 	if (clk->ops->find_idlest)
215 		_omap2_module_wait_ready(clk);
216 
217 	return 0;
218 }
219 
omap2_dflt_clk_disable(struct clk * clk)220 void omap2_dflt_clk_disable(struct clk *clk)
221 {
222 	u32 v;
223 
224 	if (!clk->enable_reg) {
225 		/*
226 		 * 'Independent' here refers to a clock which is not
227 		 * controlled by its parent.
228 		 */
229 		printk(KERN_ERR "clock: clk_disable called on independent "
230 		       "clock %s which has no enable_reg\n", clk->name);
231 		return;
232 	}
233 
234 	v = __raw_readl(clk->enable_reg);
235 	if (clk->flags & INVERT_ENABLE)
236 		v |= (1 << clk->enable_bit);
237 	else
238 		v &= ~(1 << clk->enable_bit);
239 	__raw_writel(v, clk->enable_reg);
240 	/* No OCP barrier needed here since it is a disable operation */
241 }
242 
243 const struct clkops clkops_omap2_dflt_wait = {
244 	.enable		= omap2_dflt_clk_enable,
245 	.disable	= omap2_dflt_clk_disable,
246 	.find_companion	= omap2_clk_dflt_find_companion,
247 	.find_idlest	= omap2_clk_dflt_find_idlest,
248 };
249 
250 const struct clkops clkops_omap2_dflt = {
251 	.enable		= omap2_dflt_clk_enable,
252 	.disable	= omap2_dflt_clk_disable,
253 };
254 
255 /**
256  * omap2_clk_disable - disable a clock, if the system is not using it
257  * @clk: struct clk * to disable
258  *
259  * Decrements the usecount on struct clk @clk.  If there are no users
260  * left, call the clkops-specific clock disable function to disable it
261  * in hardware.  If the clock is part of a clockdomain (which they all
262  * should be), request that the clockdomain be disabled.  (It too has
263  * a usecount, and so will not be disabled in the hardware until it no
264  * longer has any users.)  If the clock has a parent clock (most of
265  * them do), then call ourselves, recursing on the parent clock.  This
266  * can cause an entire branch of the clock tree to be powered off by
267  * simply disabling one clock.  Intended to be called with the clockfw_lock
268  * spinlock held.  No return value.
269  */
omap2_clk_disable(struct clk * clk)270 void omap2_clk_disable(struct clk *clk)
271 {
272 	if (clk->usecount == 0) {
273 		WARN(1, "clock: %s: omap2_clk_disable() called, but usecount "
274 		     "already 0?", clk->name);
275 		return;
276 	}
277 
278 	pr_debug("clock: %s: decrementing usecount\n", clk->name);
279 
280 	clk->usecount--;
281 
282 	if (clk->usecount > 0)
283 		return;
284 
285 	pr_debug("clock: %s: disabling in hardware\n", clk->name);
286 
287 	if (clk->ops && clk->ops->disable) {
288 		trace_clock_disable(clk->name, 0, smp_processor_id());
289 		clk->ops->disable(clk);
290 	}
291 
292 	if (clkdm_control && clk->clkdm)
293 		clkdm_clk_disable(clk->clkdm, clk);
294 
295 	if (clk->parent)
296 		omap2_clk_disable(clk->parent);
297 }
298 
299 /**
300  * omap2_clk_enable - request that the system enable a clock
301  * @clk: struct clk * to enable
302  *
303  * Increments the usecount on struct clk @clk.  If there were no users
304  * previously, then recurse up the clock tree, enabling all of the
305  * clock's parents and all of the parent clockdomains, and finally,
306  * enabling @clk's clockdomain, and @clk itself.  Intended to be
307  * called with the clockfw_lock spinlock held.  Returns 0 upon success
308  * or a negative error code upon failure.
309  */
omap2_clk_enable(struct clk * clk)310 int omap2_clk_enable(struct clk *clk)
311 {
312 	int ret;
313 
314 	pr_debug("clock: %s: incrementing usecount\n", clk->name);
315 
316 	clk->usecount++;
317 
318 	if (clk->usecount > 1)
319 		return 0;
320 
321 	pr_debug("clock: %s: enabling in hardware\n", clk->name);
322 
323 	if (clk->parent) {
324 		ret = omap2_clk_enable(clk->parent);
325 		if (ret) {
326 			WARN(1, "clock: %s: could not enable parent %s: %d\n",
327 			     clk->name, clk->parent->name, ret);
328 			goto oce_err1;
329 		}
330 	}
331 
332 	if (clkdm_control && clk->clkdm) {
333 		ret = clkdm_clk_enable(clk->clkdm, clk);
334 		if (ret) {
335 			WARN(1, "clock: %s: could not enable clockdomain %s: "
336 			     "%d\n", clk->name, clk->clkdm->name, ret);
337 			goto oce_err2;
338 		}
339 	}
340 
341 	if (clk->ops && clk->ops->enable) {
342 		trace_clock_enable(clk->name, 1, smp_processor_id());
343 		ret = clk->ops->enable(clk);
344 		if (ret) {
345 			WARN(1, "clock: %s: could not enable: %d\n",
346 			     clk->name, ret);
347 			goto oce_err3;
348 		}
349 	}
350 
351 	return 0;
352 
353 oce_err3:
354 	if (clkdm_control && clk->clkdm)
355 		clkdm_clk_disable(clk->clkdm, clk);
356 oce_err2:
357 	if (clk->parent)
358 		omap2_clk_disable(clk->parent);
359 oce_err1:
360 	clk->usecount--;
361 
362 	return ret;
363 }
364 
365 /* Given a clock and a rate apply a clock specific rounding function */
omap2_clk_round_rate(struct clk * clk,unsigned long rate)366 long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
367 {
368 	if (clk->round_rate)
369 		return clk->round_rate(clk, rate);
370 
371 	return clk->rate;
372 }
373 
374 /* Set the clock rate for a clock source */
omap2_clk_set_rate(struct clk * clk,unsigned long rate)375 int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
376 {
377 	int ret = -EINVAL;
378 
379 	pr_debug("clock: set_rate for clock %s to rate %ld\n", clk->name, rate);
380 
381 	/* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
382 	if (clk->set_rate) {
383 		trace_clock_set_rate(clk->name, rate, smp_processor_id());
384 		ret = clk->set_rate(clk, rate);
385 	}
386 
387 	return ret;
388 }
389 
omap2_clk_set_parent(struct clk * clk,struct clk * new_parent)390 int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
391 {
392 	if (!clk->clksel)
393 		return -EINVAL;
394 
395 	if (clk->parent == new_parent)
396 		return 0;
397 
398 	return omap2_clksel_set_parent(clk, new_parent);
399 }
400 
401 /* OMAP3/4 non-CORE DPLL clkops */
402 
403 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
404 
405 const struct clkops clkops_omap3_noncore_dpll_ops = {
406 	.enable		= omap3_noncore_dpll_enable,
407 	.disable	= omap3_noncore_dpll_disable,
408 	.allow_idle	= omap3_dpll_allow_idle,
409 	.deny_idle	= omap3_dpll_deny_idle,
410 };
411 
412 const struct clkops clkops_omap3_core_dpll_ops = {
413 	.allow_idle	= omap3_dpll_allow_idle,
414 	.deny_idle	= omap3_dpll_deny_idle,
415 };
416 
417 #endif
418 
419 /*
420  * OMAP2+ clock reset and init functions
421  */
422 
423 #ifdef CONFIG_OMAP_RESET_CLOCKS
omap2_clk_disable_unused(struct clk * clk)424 void omap2_clk_disable_unused(struct clk *clk)
425 {
426 	u32 regval32, v;
427 
428 	v = (clk->flags & INVERT_ENABLE) ? (1 << clk->enable_bit) : 0;
429 
430 	regval32 = __raw_readl(clk->enable_reg);
431 	if ((regval32 & (1 << clk->enable_bit)) == v)
432 		return;
433 
434 	pr_debug("Disabling unused clock \"%s\"\n", clk->name);
435 	if (cpu_is_omap34xx()) {
436 		omap2_clk_enable(clk);
437 		omap2_clk_disable(clk);
438 	} else {
439 		clk->ops->disable(clk);
440 	}
441 	if (clk->clkdm != NULL)
442 		pwrdm_clkdm_state_switch(clk->clkdm);
443 }
444 #endif
445 
446 /**
447  * omap2_clk_switch_mpurate_at_boot - switch ARM MPU rate by boot-time argument
448  * @mpurate_ck_name: clk name of the clock to change rate
449  *
450  * Change the ARM MPU clock rate to the rate specified on the command
451  * line, if one was specified.  @mpurate_ck_name should be
452  * "virt_prcm_set" on OMAP2xxx and "dpll1_ck" on OMAP34xx/OMAP36xx.
453  * XXX Does not handle voltage scaling - on OMAP2xxx this is currently
454  * handled by the virt_prcm_set clock, but this should be handled by
455  * the OPP layer.  XXX This is intended to be handled by the OPP layer
456  * code in the near future and should be removed from the clock code.
457  * Returns -EINVAL if 'mpurate' is zero or if clk_set_rate() rejects
458  * the rate, -ENOENT if the struct clk referred to by @mpurate_ck_name
459  * cannot be found, or 0 upon success.
460  */
omap2_clk_switch_mpurate_at_boot(const char * mpurate_ck_name)461 int __init omap2_clk_switch_mpurate_at_boot(const char *mpurate_ck_name)
462 {
463 	struct clk *mpurate_ck;
464 	int r;
465 
466 	if (!mpurate)
467 		return -EINVAL;
468 
469 	mpurate_ck = clk_get(NULL, mpurate_ck_name);
470 	if (WARN(IS_ERR(mpurate_ck), "Failed to get %s.\n", mpurate_ck_name))
471 		return -ENOENT;
472 
473 	r = clk_set_rate(mpurate_ck, mpurate);
474 	if (IS_ERR_VALUE(r)) {
475 		WARN(1, "clock: %s: unable to set MPU rate to %d: %d\n",
476 		     mpurate_ck->name, mpurate, r);
477 		clk_put(mpurate_ck);
478 		return -EINVAL;
479 	}
480 
481 	calibrate_delay();
482 	recalculate_root_clocks();
483 
484 	clk_put(mpurate_ck);
485 
486 	return 0;
487 }
488 
489 /**
490  * omap2_clk_print_new_rates - print summary of current clock tree rates
491  * @hfclkin_ck_name: clk name for the off-chip HF oscillator
492  * @core_ck_name: clk name for the on-chip CORE_CLK
493  * @mpu_ck_name: clk name for the ARM MPU clock
494  *
495  * Prints a short message to the console with the HFCLKIN oscillator
496  * rate, the rate of the CORE clock, and the rate of the ARM MPU clock.
497  * Called by the boot-time MPU rate switching code.   XXX This is intended
498  * to be handled by the OPP layer code in the near future and should be
499  * removed from the clock code.  No return value.
500  */
omap2_clk_print_new_rates(const char * hfclkin_ck_name,const char * core_ck_name,const char * mpu_ck_name)501 void __init omap2_clk_print_new_rates(const char *hfclkin_ck_name,
502 				      const char *core_ck_name,
503 				      const char *mpu_ck_name)
504 {
505 	struct clk *hfclkin_ck, *core_ck, *mpu_ck;
506 	unsigned long hfclkin_rate;
507 
508 	mpu_ck = clk_get(NULL, mpu_ck_name);
509 	if (WARN(IS_ERR(mpu_ck), "clock: failed to get %s.\n", mpu_ck_name))
510 		return;
511 
512 	core_ck = clk_get(NULL, core_ck_name);
513 	if (WARN(IS_ERR(core_ck), "clock: failed to get %s.\n", core_ck_name))
514 		return;
515 
516 	hfclkin_ck = clk_get(NULL, hfclkin_ck_name);
517 	if (WARN(IS_ERR(hfclkin_ck), "Failed to get %s.\n", hfclkin_ck_name))
518 		return;
519 
520 	hfclkin_rate = clk_get_rate(hfclkin_ck);
521 
522 	pr_info("Switched to new clocking rate (Crystal/Core/MPU): "
523 		"%ld.%01ld/%ld/%ld MHz\n",
524 		(hfclkin_rate / 1000000),
525 		((hfclkin_rate / 100000) % 10),
526 		(clk_get_rate(core_ck) / 1000000),
527 		(clk_get_rate(mpu_ck) / 1000000));
528 }
529 
530 /* Common data */
531 
532 struct clk_functions omap2_clk_functions = {
533 	.clk_enable		= omap2_clk_enable,
534 	.clk_disable		= omap2_clk_disable,
535 	.clk_round_rate		= omap2_clk_round_rate,
536 	.clk_set_rate		= omap2_clk_set_rate,
537 	.clk_set_parent		= omap2_clk_set_parent,
538 	.clk_disable_unused	= omap2_clk_disable_unused,
539 };
540 
541