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