2 * linux/arch/arm/mach-omap2/clock.c
4 * Copyright (C) 2005 Texas Instruments Inc.
5 * Richard Woodruff <r-woodruff2@ti.com>
8 * Cleaned up and modified to use omap shared clock framework by
9 * Tony Lindgren <tony@atomide.com>
11 * Copyright (C) 2007 Texas Instruments, Inc.
12 * Copyright (C) 2007 Nokia Corporation
15 * Based on omap1 clock.c, Copyright (C) 2004 - 2005 Nokia corporation
16 * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License version 2 as
20 * published by the Free Software Foundation.
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/device.h>
27 #include <linux/list.h>
28 #include <linux/errno.h>
29 #include <linux/delay.h>
30 #include <linux/clk.h>
31 #include <asm/bitops.h>
35 #include <asm/arch/clock.h>
36 #include <asm/arch/sram.h>
37 #include <asm/arch/cpu.h>
38 #include <asm/div64.h>
44 #include "prm-regbits-24xx.h"
46 #include "cm-regbits-24xx.h"
47 #include "cm-regbits-34xx.h"
49 #define MAX_CLOCK_ENABLE_WAIT 100000
53 /*-------------------------------------------------------------------------
54 * Omap2 specific clock functions
55 *-------------------------------------------------------------------------*/
58 * omap2_init_clksel_parent - set a clksel clk's parent field from the hardware
59 * @clk: OMAP clock struct ptr to use
61 * Given a pointer to a source-selectable struct clk, read the hardware
62 * register and determine what its parent is currently set to. Update the
63 * clk->parent field with the appropriate clk ptr.
65 void omap2_init_clksel_parent(struct clk *clk)
67 const struct clksel *clks;
68 const struct clksel_rate *clkr;
74 r = __raw_readl(clk->clksel_reg) & clk->clksel_mask;
75 r >>= __ffs(clk->clksel_mask);
77 for (clks = clk->clksel; clks->parent && !found; clks++) {
78 for (clkr = clks->rates; clkr->div && !found; clkr++) {
79 if ((clkr->flags & cpu_mask) && (clkr->val == r)) {
80 if (clk->parent != clks->parent) {
81 pr_debug("clock: inited %s parent "
83 clk->name, clks->parent->name,
85 clk->parent->name : "NULL"));
86 clk->parent = clks->parent;
94 printk(KERN_ERR "clock: init parent: could not find "
95 "regval %0x for clock %s\n", r, clk->name);
100 /* Returns the DPLL rate */
101 u32 omap2_get_dpll_rate(struct clk *clk)
104 u32 dpll_mult, dpll_div, dpll;
105 const struct dpll_data *dd;
108 /* REVISIT: What do we return on error? */
112 dpll = __raw_readl(dd->mult_div1_reg);
113 dpll_mult = dpll & dd->mult_mask;
114 dpll_mult >>= __ffs(dd->mult_mask);
115 dpll_div = dpll & dd->div1_mask;
116 dpll_div >>= __ffs(dd->div1_mask);
118 dpll_clk = (long long)clk->parent->rate * dpll_mult;
119 do_div(dpll_clk, dpll_div + 1);
123 dpll = __raw_readl(dd->div2_reg);
124 dpll_div = dpll & dd->div2_mask;
125 dpll_div >>= __ffs(dd->div2_mask);
126 do_div(dpll_clk, dpll_div + 1);
133 * Used for clocks that have the same value as the parent clock,
134 * divided by some factor
136 void omap2_fixed_divisor_recalc(struct clk *clk)
138 WARN_ON(!clk->fixed_div);
140 clk->rate = clk->parent->rate / clk->fixed_div;
142 if (clk->flags & RATE_PROPAGATES)
147 * omap2_wait_clock_ready - wait for clock to enable
148 * @reg: physical address of clock IDLEST register
149 * @mask: value to mask against to determine if the clock is active
150 * @name: name of the clock (for printk)
152 * Returns 1 if the clock enabled in time, or 0 if it failed to enable
153 * in roughly MAX_CLOCK_ENABLE_WAIT microseconds.
155 int omap2_wait_clock_ready(void __iomem *reg, u32 mask, const char *name)
161 * 24xx uses 0 to indicate not ready, and 1 to indicate ready.
162 * 34xx reverses this, just to keep us on our toes
164 if (cpu_mask & (RATE_IN_242X | RATE_IN_243X)) {
166 } else if (cpu_mask & RATE_IN_343X) {
171 while (((__raw_readl(reg) & mask) != ena) &&
172 (i++ < MAX_CLOCK_ENABLE_WAIT)) {
176 if (i < MAX_CLOCK_ENABLE_WAIT)
177 pr_debug("Clock %s stable after %d loops\n", name, i);
179 printk(KERN_ERR "Clock %s didn't enable in %d tries\n",
180 name, MAX_CLOCK_ENABLE_WAIT);
183 return (i < MAX_CLOCK_ENABLE_WAIT) ? 1 : 0;
188 * Note: We don't need special code here for INVERT_ENABLE
189 * for the time being since INVERT_ENABLE only applies to clocks enabled by
192 static void omap2_clk_wait_ready(struct clk *clk)
194 void __iomem *reg, *other_reg, *st_reg;
198 * REVISIT: This code is pretty ugly. It would be nice to generalize
199 * it and pull it into struct clk itself somehow.
201 reg = clk->enable_reg;
202 if ((((u32)reg & 0xff) >= CM_FCLKEN1) &&
203 (((u32)reg & 0xff) <= OMAP24XX_CM_FCLKEN2))
204 other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x10); /* CM_ICLKEN* */
205 else if ((((u32)reg & 0xff) >= CM_ICLKEN1) &&
206 (((u32)reg & 0xff) <= OMAP24XX_CM_ICLKEN4))
207 other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x00); /* CM_FCLKEN* */
211 /* REVISIT: What are the appropriate exclusions for 34XX? */
212 /* No check for DSS or cam clocks */
213 if (cpu_is_omap24xx() && ((u32)reg & 0x0f) == 0) { /* CM_{F,I}CLKEN1 */
214 if (clk->enable_bit == OMAP24XX_EN_DSS2_SHIFT ||
215 clk->enable_bit == OMAP24XX_EN_DSS1_SHIFT ||
216 clk->enable_bit == OMAP24XX_EN_CAM_SHIFT)
220 /* REVISIT: What are the appropriate exclusions for 34XX? */
221 /* OMAP3: ignore DSS-mod clocks */
222 if (cpu_is_omap34xx() &&
223 (((u32)reg & ~0xff) == (u32)OMAP_CM_REGADDR(OMAP3430_DSS_MOD, 0)))
226 /* Check if both functional and interface clocks
228 bit = 1 << clk->enable_bit;
229 if (!(__raw_readl(other_reg) & bit))
231 st_reg = (void __iomem *)(((u32)other_reg & ~0xf0) | 0x20); /* CM_IDLEST* */
233 omap2_wait_clock_ready(st_reg, bit, clk->name);
236 /* Enables clock without considering parent dependencies or use count
237 * REVISIT: Maybe change this to use clk->enable like on omap1?
239 int _omap2_clk_enable(struct clk *clk)
243 if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK))
247 return clk->enable(clk);
249 if (unlikely(clk->enable_reg == 0)) {
250 printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
252 return 0; /* REVISIT: -EINVAL */
255 regval32 = __raw_readl(clk->enable_reg);
256 if (clk->flags & INVERT_ENABLE)
257 regval32 &= ~(1 << clk->enable_bit);
259 regval32 |= (1 << clk->enable_bit);
260 __raw_writel(regval32, clk->enable_reg);
263 omap2_clk_wait_ready(clk);
268 /* Disables clock without considering parent dependencies or use count */
269 void _omap2_clk_disable(struct clk *clk)
273 if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK))
281 if (clk->enable_reg == 0) {
283 * 'Independent' here refers to a clock which is not
284 * controlled by its parent.
286 printk(KERN_ERR "clock: clk_disable called on independent "
287 "clock %s which has no enable_reg\n", clk->name);
291 regval32 = __raw_readl(clk->enable_reg);
292 if (clk->flags & INVERT_ENABLE)
293 regval32 |= (1 << clk->enable_bit);
295 regval32 &= ~(1 << clk->enable_bit);
296 __raw_writel(regval32, clk->enable_reg);
300 void omap2_clk_disable(struct clk *clk)
302 if (clk->usecount > 0 && !(--clk->usecount)) {
303 _omap2_clk_disable(clk);
304 if (likely((u32)clk->parent))
305 omap2_clk_disable(clk->parent);
309 int omap2_clk_enable(struct clk *clk)
313 if (clk->usecount++ == 0) {
314 if (likely((u32)clk->parent))
315 ret = omap2_clk_enable(clk->parent);
317 if (unlikely(ret != 0)) {
322 ret = _omap2_clk_enable(clk);
324 if (unlikely(ret != 0) && clk->parent) {
325 omap2_clk_disable(clk->parent);
334 * Used for clocks that are part of CLKSEL_xyz governed clocks.
335 * REVISIT: Maybe change to use clk->enable() functions like on omap1?
337 void omap2_clksel_recalc(struct clk *clk)
341 pr_debug("clock: recalc'ing clksel clk %s\n", clk->name);
343 div = omap2_clksel_get_divisor(clk);
347 if (unlikely(clk->rate == clk->parent->rate / div))
349 clk->rate = clk->parent->rate / div;
351 pr_debug("clock: new clock rate is %ld (div %d)\n", clk->rate, div);
353 if (unlikely(clk->flags & RATE_PROPAGATES))
358 * omap2_get_clksel_by_parent - return clksel struct for a given clk & parent
359 * @clk: OMAP struct clk ptr to inspect
360 * @src_clk: OMAP struct clk ptr of the parent clk to search for
362 * Scan the struct clksel array associated with the clock to find
363 * the element associated with the supplied parent clock address.
364 * Returns a pointer to the struct clksel on success or NULL on error.
366 const struct clksel *omap2_get_clksel_by_parent(struct clk *clk,
369 const struct clksel *clks;
374 for (clks = clk->clksel; clks->parent; clks++) {
375 if (clks->parent == src_clk)
376 break; /* Found the requested parent */
380 printk(KERN_ERR "clock: Could not find parent clock %s in "
381 "clksel array of clock %s\n", src_clk->name,
390 * omap2_clksel_round_rate_div - find divisor for the given clock and rate
391 * @clk: OMAP struct clk to use
392 * @target_rate: desired clock rate
393 * @new_div: ptr to where we should store the divisor
395 * Finds 'best' divider value in an array based on the source and target
396 * rates. The divider array must be sorted with smallest divider first.
397 * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
398 * they are only settable as part of virtual_prcm set.
400 * Returns the rounded clock rate or returns 0xffffffff on error.
402 u32 omap2_clksel_round_rate_div(struct clk *clk, unsigned long target_rate,
405 unsigned long test_rate;
406 const struct clksel *clks;
407 const struct clksel_rate *clkr;
410 printk(KERN_INFO "clock: clksel_round_rate_div: %s target_rate %ld\n",
411 clk->name, target_rate);
415 clks = omap2_get_clksel_by_parent(clk, clk->parent);
419 for (clkr = clks->rates; clkr->div; clkr++) {
420 if (!(clkr->flags & cpu_mask))
424 if (clkr->div <= last_div)
425 printk(KERN_ERR "clock: clksel_rate table not sorted "
426 "for clock %s", clk->name);
428 last_div = clkr->div;
430 test_rate = clk->parent->rate / clkr->div;
432 if (test_rate <= target_rate)
433 break; /* found it */
437 printk(KERN_ERR "clock: Could not find divisor for target "
438 "rate %ld for clock %s parent %s\n", target_rate,
439 clk->name, clk->parent->name);
443 *new_div = clkr->div;
445 printk(KERN_INFO "clock: new_div = %d, new_rate = %ld\n", *new_div,
446 (clk->parent->rate / clkr->div));
448 return (clk->parent->rate / clkr->div);
452 * omap2_clksel_round_rate - find rounded rate for the given clock and rate
453 * @clk: OMAP struct clk to use
454 * @target_rate: desired clock rate
456 * Compatibility wrapper for OMAP clock framework
457 * Finds best target rate based on the source clock and possible dividers.
458 * rates. The divider array must be sorted with smallest divider first.
459 * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
460 * they are only settable as part of virtual_prcm set.
462 * Returns the rounded clock rate or returns 0xffffffff on error.
464 long omap2_clksel_round_rate(struct clk *clk, unsigned long target_rate)
468 return omap2_clksel_round_rate_div(clk, target_rate, &new_div);
472 /* Given a clock and a rate apply a clock specific rounding function */
473 long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
475 if (clk->round_rate != 0)
476 return clk->round_rate(clk, rate);
478 if (clk->flags & RATE_FIXED)
479 printk(KERN_ERR "clock: generic omap2_clk_round_rate called "
480 "on fixed-rate clock %s\n", clk->name);
486 * omap2_clksel_to_divisor() - turn clksel field value into integer divider
487 * @clk: OMAP struct clk to use
488 * @field_val: register field value to find
490 * Given a struct clk of a rate-selectable clksel clock, and a register field
491 * value to search for, find the corresponding clock divisor. The register
492 * field value should be pre-masked and shifted down so the LSB is at bit 0
493 * before calling. Returns 0 on error
495 u32 omap2_clksel_to_divisor(struct clk *clk, u32 field_val)
497 const struct clksel *clks;
498 const struct clksel_rate *clkr;
500 clks = omap2_get_clksel_by_parent(clk, clk->parent);
504 for (clkr = clks->rates; clkr->div; clkr++) {
505 if ((clkr->flags & cpu_mask) && (clkr->val == field_val))
510 printk(KERN_ERR "clock: Could not find fieldval %d for "
511 "clock %s parent %s\n", field_val, clk->name,
520 * omap2_divisor_to_clksel() - turn clksel integer divisor into a field value
521 * @clk: OMAP struct clk to use
522 * @div: integer divisor to search for
524 * Given a struct clk of a rate-selectable clksel clock, and a clock divisor,
525 * find the corresponding register field value. The return register value is
526 * the value before left-shifting. Returns 0xffffffff on error
528 u32 omap2_divisor_to_clksel(struct clk *clk, u32 div)
530 const struct clksel *clks;
531 const struct clksel_rate *clkr;
533 /* should never happen */
536 clks = omap2_get_clksel_by_parent(clk, clk->parent);
540 for (clkr = clks->rates; clkr->div; clkr++) {
541 if ((clkr->flags & cpu_mask) && (clkr->div == div))
546 printk(KERN_ERR "clock: Could not find divisor %d for "
547 "clock %s parent %s\n", div, clk->name,
556 * omap2_get_clksel - find clksel register addr & field mask for a clk
557 * @clk: struct clk to use
558 * @field_mask: ptr to u32 to store the register field mask
560 * Returns the address of the clksel register upon success or NULL on error.
562 void __iomem *omap2_get_clksel(struct clk *clk, u32 *field_mask)
564 if (unlikely((clk->clksel_reg == 0) || (clk->clksel_mask == 0)))
567 *field_mask = clk->clksel_mask;
569 return clk->clksel_reg;
573 * omap2_clksel_get_divisor - get current divider applied to parent clock.
574 * @clk: OMAP struct clk to use.
576 * Returns the integer divisor upon success or 0 on error.
578 u32 omap2_clksel_get_divisor(struct clk *clk)
580 u32 field_mask, field_val;
581 void __iomem *div_addr;
583 div_addr = omap2_get_clksel(clk, &field_mask);
587 field_val = __raw_readl(div_addr) & field_mask;
588 field_val >>= __ffs(field_mask);
590 return omap2_clksel_to_divisor(clk, field_val);
593 int omap2_clksel_set_rate(struct clk *clk, unsigned long rate)
595 u32 field_mask, field_val, reg_val, validrate, new_div = 0;
596 void __iomem *div_addr;
598 validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
599 if (validrate != rate)
602 div_addr = omap2_get_clksel(clk, &field_mask);
606 field_val = omap2_divisor_to_clksel(clk, new_div);
610 reg_val = __raw_readl(div_addr);
611 reg_val &= ~field_mask;
612 reg_val |= (field_val << __ffs(field_mask));
613 __raw_writel(reg_val, div_addr);
616 clk->rate = clk->parent->rate / new_div;
618 if (clk->flags & DELAYED_APP && cpu_is_omap24xx()) {
619 __raw_writel(OMAP24XX_VALID_CONFIG, OMAP24XX_PRCM_CLKCFG_CTRL);
627 /* Set the clock rate for a clock source */
628 int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
632 pr_debug("clock: set_rate for clock %s to rate %ld\n", clk->name, rate);
634 /* CONFIG_PARTICIPANT clocks are changed only in sets via the
635 rate table mechanism, driven by mpu_speed */
636 if (clk->flags & CONFIG_PARTICIPANT)
639 /* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
640 if (clk->set_rate != 0)
641 ret = clk->set_rate(clk, rate);
643 if (unlikely(ret == 0 && (clk->flags & RATE_PROPAGATES)))
650 * Converts encoded control register address into a full address
651 * On error, *src_addr will be returned as 0.
653 static u32 omap2_clksel_get_src_field(void __iomem **src_addr,
654 struct clk *src_clk, u32 *field_mask,
655 struct clk *clk, u32 *parent_div)
657 const struct clksel *clks;
658 const struct clksel_rate *clkr;
663 clks = omap2_get_clksel_by_parent(clk, src_clk);
667 for (clkr = clks->rates; clkr->div; clkr++) {
668 if (clkr->flags & (cpu_mask | DEFAULT_RATE))
669 break; /* Found the default rate for this platform */
673 printk(KERN_ERR "clock: Could not find default rate for "
674 "clock %s parent %s\n", clk->name,
675 src_clk->parent->name);
679 /* Should never happen. Add a clksel mask to the struct clk. */
680 WARN_ON(clk->clksel_mask == 0);
682 *field_mask = clk->clksel_mask;
683 *src_addr = clk->clksel_reg;
684 *parent_div = clkr->div;
689 int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
691 void __iomem *src_addr;
692 u32 field_val, field_mask, reg_val, parent_div;
694 if (unlikely(clk->flags & CONFIG_PARTICIPANT))
700 field_val = omap2_clksel_get_src_field(&src_addr, new_parent,
701 &field_mask, clk, &parent_div);
705 if (clk->usecount > 0)
706 _omap2_clk_disable(clk);
708 /* Set new source value (previous dividers if any in effect) */
709 reg_val = __raw_readl(src_addr) & ~field_mask;
710 reg_val |= (field_val << __ffs(field_mask));
711 __raw_writel(reg_val, src_addr);
714 if (clk->flags & DELAYED_APP && cpu_is_omap24xx()) {
715 __raw_writel(OMAP24XX_VALID_CONFIG, OMAP24XX_PRCM_CLKCFG_CTRL);
719 if (clk->usecount > 0)
720 _omap2_clk_enable(clk);
722 clk->parent = new_parent;
724 /* CLKSEL clocks follow their parents' rates, divided by a divisor */
725 clk->rate = new_parent->rate;
728 clk->rate /= parent_div;
730 pr_debug("clock: set parent of %s to %s (new rate %ld)\n",
731 clk->name, clk->parent->name, clk->rate);
733 if (unlikely(clk->flags & RATE_PROPAGATES))
739 /*-------------------------------------------------------------------------
740 * Omap2 clock reset and init functions
741 *-------------------------------------------------------------------------*/
743 #ifdef CONFIG_OMAP_RESET_CLOCKS
744 void omap2_clk_disable_unused(struct clk *clk)
748 v = (clk->flags & INVERT_ENABLE) ? (1 << clk->enable_bit) : 0;
750 regval32 = __raw_readl(clk->enable_reg);
751 if ((regval32 & (1 << clk->enable_bit)) == v)
754 printk(KERN_INFO "Disabling unused clock \"%s\"\n", clk->name);
755 _omap2_clk_disable(clk);