2 * linux/arch/arm/mach-omap2/clock.c
4 * Copyright (C) 2005-2008 Texas Instruments, Inc.
5 * Copyright (C) 2004-2008 Nokia Corporation
8 * Richard Woodruff <r-woodruff2@ti.com>
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.
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20 #include <linux/list.h>
21 #include <linux/errno.h>
22 #include <linux/delay.h>
23 #include <linux/clk.h>
27 #include <asm/arch/clock.h>
28 #include <asm/arch/sram.h>
29 #include <asm/arch/cpu.h>
30 #include <asm/div64.h>
36 #include "prm-regbits-24xx.h"
38 #include "cm-regbits-24xx.h"
39 #include "cm-regbits-34xx.h"
41 #define MAX_CLOCK_ENABLE_WAIT 100000
45 /*-------------------------------------------------------------------------
46 * Omap2 specific clock functions
47 *-------------------------------------------------------------------------*/
49 u8 mask_to_shift(u32 mask)
55 * omap2_init_clksel_parent - set a clksel clk's parent field from the hardware
56 * @clk: OMAP clock struct ptr to use
58 * Given a pointer to a source-selectable struct clk, read the hardware
59 * register and determine what its parent is currently set to. Update the
60 * clk->parent field with the appropriate clk ptr.
62 void omap2_init_clksel_parent(struct clk *clk)
64 const struct clksel *clks;
65 const struct clksel_rate *clkr;
71 r = __raw_readl(clk->clksel_reg) & clk->clksel_mask;
72 r >>= mask_to_shift(clk->clksel_mask);
74 for (clks = clk->clksel; clks->parent && !found; clks++) {
75 for (clkr = clks->rates; clkr->div && !found; clkr++) {
76 if ((clkr->flags & cpu_mask) && (clkr->val == r)) {
77 if (clk->parent != clks->parent) {
78 pr_debug("clock: inited %s parent "
80 clk->name, clks->parent->name,
82 clk->parent->name : "NULL"));
83 clk->parent = clks->parent;
91 printk(KERN_ERR "clock: init parent: could not find "
92 "regval %0x for clock %s\n", r, clk->name);
97 /* Returns the DPLL rate */
98 u32 omap2_get_dpll_rate(struct clk *clk)
101 u32 dpll_mult, dpll_div, dpll;
102 const struct dpll_data *dd;
105 /* REVISIT: What do we return on error? */
109 dpll = cm_read_reg(dd->mult_div1_reg);
110 dpll_mult = dpll & dd->mult_mask;
111 dpll_mult >>= mask_to_shift(dd->mult_mask);
112 dpll_div = dpll & dd->div1_mask;
113 dpll_div >>= mask_to_shift(dd->div1_mask);
115 dpll_clk = (long long)clk->parent->rate * dpll_mult;
116 do_div(dpll_clk, dpll_div + 1);
122 * Used for clocks that have the same value as the parent clock,
123 * divided by some factor
125 void omap2_fixed_divisor_recalc(struct clk *clk)
127 WARN_ON(!clk->fixed_div);
129 clk->rate = clk->parent->rate / clk->fixed_div;
131 if (clk->flags & RATE_PROPAGATES)
136 * omap2_wait_clock_ready - wait for clock to enable
137 * @reg: physical address of clock IDLEST register
138 * @mask: value to mask against to determine if the clock is active
139 * @name: name of the clock (for printk)
141 * Returns 1 if the clock enabled in time, or 0 if it failed to enable
142 * in roughly MAX_CLOCK_ENABLE_WAIT microseconds.
144 int omap2_wait_clock_ready(void __iomem *reg, u32 mask, const char *name)
150 * 24xx uses 0 to indicate not ready, and 1 to indicate ready.
151 * 34xx reverses this, just to keep us on our toes
153 if (cpu_mask & (RATE_IN_242X | RATE_IN_243X)) {
155 } else if (cpu_mask & RATE_IN_343X) {
160 while (((cm_read_reg(reg) & mask) != ena) &&
161 (i++ < MAX_CLOCK_ENABLE_WAIT)) {
165 if (i < MAX_CLOCK_ENABLE_WAIT)
166 pr_debug("Clock %s stable after %d loops\n", name, i);
168 printk(KERN_ERR "Clock %s didn't enable in %d tries\n",
169 name, MAX_CLOCK_ENABLE_WAIT);
172 return (i < MAX_CLOCK_ENABLE_WAIT) ? 1 : 0;
177 * Note: We don't need special code here for INVERT_ENABLE
178 * for the time being since INVERT_ENABLE only applies to clocks enabled by
181 static void omap2_clk_wait_ready(struct clk *clk)
183 void __iomem *reg, *other_reg, *st_reg;
187 * REVISIT: This code is pretty ugly. It would be nice to generalize
188 * it and pull it into struct clk itself somehow.
190 reg = clk->enable_reg;
191 if ((((u32)reg & 0xff) >= CM_FCLKEN1) &&
192 (((u32)reg & 0xff) <= OMAP24XX_CM_FCLKEN2))
193 other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x10); /* CM_ICLKEN* */
194 else if ((((u32)reg & 0xff) >= CM_ICLKEN1) &&
195 (((u32)reg & 0xff) <= OMAP24XX_CM_ICLKEN4))
196 other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x00); /* CM_FCLKEN* */
200 /* REVISIT: What are the appropriate exclusions for 34XX? */
201 /* No check for DSS or cam clocks */
202 if (cpu_is_omap24xx() && ((u32)reg & 0x0f) == 0) { /* CM_{F,I}CLKEN1 */
203 if (clk->enable_bit == OMAP24XX_EN_DSS2_SHIFT ||
204 clk->enable_bit == OMAP24XX_EN_DSS1_SHIFT ||
205 clk->enable_bit == OMAP24XX_EN_CAM_SHIFT)
209 /* REVISIT: What are the appropriate exclusions for 34XX? */
210 /* OMAP3: ignore DSS-mod clocks */
211 if (cpu_is_omap34xx() &&
212 (((u32)reg & ~0xff) == (u32)OMAP_CM_REGADDR(OMAP3430_DSS_MOD, 0)))
215 /* Check if both functional and interface clocks
217 bit = 1 << clk->enable_bit;
218 if (!(cm_read_reg(other_reg) & bit))
220 st_reg = (void __iomem *)(((u32)other_reg & ~0xf0) | 0x20); /* CM_IDLEST* */
222 omap2_wait_clock_ready(st_reg, bit, clk->name);
225 /* Enables clock without considering parent dependencies or use count
226 * REVISIT: Maybe change this to use clk->enable like on omap1?
228 int _omap2_clk_enable(struct clk *clk)
232 if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK))
236 return clk->enable(clk);
238 if (unlikely(clk->enable_reg == 0)) {
239 printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
241 return 0; /* REVISIT: -EINVAL */
244 regval32 = cm_read_reg(clk->enable_reg);
245 if (clk->flags & INVERT_ENABLE)
246 regval32 &= ~(1 << clk->enable_bit);
248 regval32 |= (1 << clk->enable_bit);
249 cm_write_reg(regval32, clk->enable_reg);
252 omap2_clk_wait_ready(clk);
257 /* Disables clock without considering parent dependencies or use count */
258 void _omap2_clk_disable(struct clk *clk)
262 if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK))
270 if (clk->enable_reg == 0) {
272 * 'Independent' here refers to a clock which is not
273 * controlled by its parent.
275 printk(KERN_ERR "clock: clk_disable called on independent "
276 "clock %s which has no enable_reg\n", clk->name);
280 regval32 = cm_read_reg(clk->enable_reg);
281 if (clk->flags & INVERT_ENABLE)
282 regval32 |= (1 << clk->enable_bit);
284 regval32 &= ~(1 << clk->enable_bit);
285 cm_write_reg(regval32, clk->enable_reg);
289 void omap2_clk_disable(struct clk *clk)
291 if (clk->usecount > 0 && !(--clk->usecount)) {
292 _omap2_clk_disable(clk);
293 if (likely((u32)clk->parent))
294 omap2_clk_disable(clk->parent);
298 int omap2_clk_enable(struct clk *clk)
302 if (clk->usecount++ == 0) {
303 if (likely((u32)clk->parent))
304 ret = omap2_clk_enable(clk->parent);
306 if (unlikely(ret != 0)) {
311 ret = _omap2_clk_enable(clk);
313 if (unlikely(ret != 0) && clk->parent) {
314 omap2_clk_disable(clk->parent);
323 * Used for clocks that are part of CLKSEL_xyz governed clocks.
324 * REVISIT: Maybe change to use clk->enable() functions like on omap1?
326 void omap2_clksel_recalc(struct clk *clk)
330 pr_debug("clock: recalc'ing clksel clk %s\n", clk->name);
332 div = omap2_clksel_get_divisor(clk);
336 if (unlikely(clk->rate == clk->parent->rate / div))
338 clk->rate = clk->parent->rate / div;
340 pr_debug("clock: new clock rate is %ld (div %d)\n", clk->rate, div);
342 if (unlikely(clk->flags & RATE_PROPAGATES))
347 * omap2_get_clksel_by_parent - return clksel struct for a given clk & parent
348 * @clk: OMAP struct clk ptr to inspect
349 * @src_clk: OMAP struct clk ptr of the parent clk to search for
351 * Scan the struct clksel array associated with the clock to find
352 * the element associated with the supplied parent clock address.
353 * Returns a pointer to the struct clksel on success or NULL on error.
355 const struct clksel *omap2_get_clksel_by_parent(struct clk *clk,
358 const struct clksel *clks;
363 for (clks = clk->clksel; clks->parent; clks++) {
364 if (clks->parent == src_clk)
365 break; /* Found the requested parent */
369 printk(KERN_ERR "clock: Could not find parent clock %s in "
370 "clksel array of clock %s\n", src_clk->name,
379 * omap2_clksel_round_rate_div - find divisor for the given clock and rate
380 * @clk: OMAP struct clk to use
381 * @target_rate: desired clock rate
382 * @new_div: ptr to where we should store the divisor
384 * Finds 'best' divider value in an array based on the source and target
385 * rates. The divider array must be sorted with smallest divider first.
386 * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
387 * they are only settable as part of virtual_prcm set.
389 * Returns the rounded clock rate or returns 0xffffffff on error.
391 u32 omap2_clksel_round_rate_div(struct clk *clk, unsigned long target_rate,
394 unsigned long test_rate;
395 const struct clksel *clks;
396 const struct clksel_rate *clkr;
399 printk(KERN_INFO "clock: clksel_round_rate_div: %s target_rate %ld\n",
400 clk->name, target_rate);
404 clks = omap2_get_clksel_by_parent(clk, clk->parent);
408 for (clkr = clks->rates; clkr->div; clkr++) {
409 if (!(clkr->flags & cpu_mask))
413 if (clkr->div <= last_div)
414 printk(KERN_ERR "clock: clksel_rate table not sorted "
415 "for clock %s", clk->name);
417 last_div = clkr->div;
419 test_rate = clk->parent->rate / clkr->div;
421 if (test_rate <= target_rate)
422 break; /* found it */
426 printk(KERN_ERR "clock: Could not find divisor for target "
427 "rate %ld for clock %s parent %s\n", target_rate,
428 clk->name, clk->parent->name);
432 *new_div = clkr->div;
434 printk(KERN_INFO "clock: new_div = %d, new_rate = %ld\n", *new_div,
435 (clk->parent->rate / clkr->div));
437 return (clk->parent->rate / clkr->div);
441 * omap2_clksel_round_rate - find rounded rate for the given clock and rate
442 * @clk: OMAP struct clk to use
443 * @target_rate: desired clock rate
445 * Compatibility wrapper for OMAP clock framework
446 * Finds best target rate based on the source clock and possible dividers.
447 * rates. The divider array must be sorted with smallest divider first.
448 * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
449 * they are only settable as part of virtual_prcm set.
451 * Returns the rounded clock rate or returns 0xffffffff on error.
453 long omap2_clksel_round_rate(struct clk *clk, unsigned long target_rate)
457 return omap2_clksel_round_rate_div(clk, target_rate, &new_div);
461 /* Given a clock and a rate apply a clock specific rounding function */
462 long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
464 if (clk->round_rate != 0)
465 return clk->round_rate(clk, rate);
467 if (clk->flags & RATE_FIXED)
468 printk(KERN_ERR "clock: generic omap2_clk_round_rate called "
469 "on fixed-rate clock %s\n", clk->name);
475 * omap2_clksel_to_divisor() - turn clksel field value into integer divider
476 * @clk: OMAP struct clk to use
477 * @field_val: register field value to find
479 * Given a struct clk of a rate-selectable clksel clock, and a register field
480 * value to search for, find the corresponding clock divisor. The register
481 * field value should be pre-masked and shifted down so the LSB is at bit 0
482 * before calling. Returns 0 on error
484 u32 omap2_clksel_to_divisor(struct clk *clk, u32 field_val)
486 const struct clksel *clks;
487 const struct clksel_rate *clkr;
489 clks = omap2_get_clksel_by_parent(clk, clk->parent);
493 for (clkr = clks->rates; clkr->div; clkr++) {
494 if ((clkr->flags & cpu_mask) && (clkr->val == field_val))
499 printk(KERN_ERR "clock: Could not find fieldval %d for "
500 "clock %s parent %s\n", field_val, clk->name,
509 * omap2_divisor_to_clksel() - turn clksel integer divisor into a field value
510 * @clk: OMAP struct clk to use
511 * @div: integer divisor to search for
513 * Given a struct clk of a rate-selectable clksel clock, and a clock divisor,
514 * find the corresponding register field value. The return register value is
515 * the value before left-shifting. Returns 0xffffffff on error
517 u32 omap2_divisor_to_clksel(struct clk *clk, u32 div)
519 const struct clksel *clks;
520 const struct clksel_rate *clkr;
522 /* should never happen */
525 clks = omap2_get_clksel_by_parent(clk, clk->parent);
529 for (clkr = clks->rates; clkr->div; clkr++) {
530 if ((clkr->flags & cpu_mask) && (clkr->div == div))
535 printk(KERN_ERR "clock: Could not find divisor %d for "
536 "clock %s parent %s\n", div, clk->name,
545 * omap2_get_clksel - find clksel register addr & field mask for a clk
546 * @clk: struct clk to use
547 * @field_mask: ptr to u32 to store the register field mask
549 * Returns the address of the clksel register upon success or NULL on error.
551 void __iomem *omap2_get_clksel(struct clk *clk, u32 *field_mask)
553 if (unlikely((clk->clksel_reg == 0) || (clk->clksel_mask == 0)))
556 *field_mask = clk->clksel_mask;
558 return clk->clksel_reg;
562 * omap2_clksel_get_divisor - get current divider applied to parent clock.
563 * @clk: OMAP struct clk to use.
565 * Returns the integer divisor upon success or 0 on error.
567 u32 omap2_clksel_get_divisor(struct clk *clk)
569 u32 field_mask, field_val;
570 void __iomem *div_addr;
572 div_addr = omap2_get_clksel(clk, &field_mask);
576 field_val = cm_read_reg(div_addr) & field_mask;
577 field_val >>= mask_to_shift(field_mask);
579 return omap2_clksel_to_divisor(clk, field_val);
582 int omap2_clksel_set_rate(struct clk *clk, unsigned long rate)
584 u32 field_mask, field_val, reg_val, validrate, new_div = 0;
585 void __iomem *div_addr;
587 validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
588 if (validrate != rate)
591 div_addr = omap2_get_clksel(clk, &field_mask);
595 field_val = omap2_divisor_to_clksel(clk, new_div);
599 reg_val = cm_read_reg(div_addr);
600 reg_val &= ~field_mask;
601 reg_val |= (field_val << mask_to_shift(field_mask));
602 cm_write_reg(reg_val, div_addr);
605 clk->rate = clk->parent->rate / new_div;
607 if (clk->flags & DELAYED_APP && cpu_is_omap24xx()) {
608 prm_write_reg(OMAP24XX_VALID_CONFIG, OMAP24XX_PRCM_CLKCFG_CTRL);
616 /* Set the clock rate for a clock source */
617 int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
621 pr_debug("clock: set_rate for clock %s to rate %ld\n", clk->name, rate);
623 /* CONFIG_PARTICIPANT clocks are changed only in sets via the
624 rate table mechanism, driven by mpu_speed */
625 if (clk->flags & CONFIG_PARTICIPANT)
628 /* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
629 if (clk->set_rate != 0)
630 ret = clk->set_rate(clk, rate);
632 if (unlikely(ret == 0 && (clk->flags & RATE_PROPAGATES)))
639 * Converts encoded control register address into a full address
640 * On error, *src_addr will be returned as 0.
642 static u32 omap2_clksel_get_src_field(void __iomem **src_addr,
643 struct clk *src_clk, u32 *field_mask,
644 struct clk *clk, u32 *parent_div)
646 const struct clksel *clks;
647 const struct clksel_rate *clkr;
652 clks = omap2_get_clksel_by_parent(clk, src_clk);
656 for (clkr = clks->rates; clkr->div; clkr++) {
657 if (clkr->flags & (cpu_mask | DEFAULT_RATE))
658 break; /* Found the default rate for this platform */
662 printk(KERN_ERR "clock: Could not find default rate for "
663 "clock %s parent %s\n", clk->name,
664 src_clk->parent->name);
668 /* Should never happen. Add a clksel mask to the struct clk. */
669 WARN_ON(clk->clksel_mask == 0);
671 *field_mask = clk->clksel_mask;
672 *src_addr = clk->clksel_reg;
673 *parent_div = clkr->div;
678 int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
680 void __iomem *src_addr;
681 u32 field_val, field_mask, reg_val, parent_div;
683 if (unlikely(clk->flags & CONFIG_PARTICIPANT))
689 field_val = omap2_clksel_get_src_field(&src_addr, new_parent,
690 &field_mask, clk, &parent_div);
694 if (clk->usecount > 0)
695 _omap2_clk_disable(clk);
697 /* Set new source value (previous dividers if any in effect) */
698 reg_val = __raw_readl(src_addr) & ~field_mask;
699 reg_val |= (field_val << mask_to_shift(field_mask));
700 __raw_writel(reg_val, src_addr);
703 if (clk->flags & DELAYED_APP && cpu_is_omap24xx()) {
704 prm_write_reg(OMAP24XX_VALID_CONFIG,
705 OMAP24XX_PRCM_CLKCFG_CTRL);
709 if (clk->usecount > 0)
710 _omap2_clk_enable(clk);
712 clk->parent = new_parent;
714 /* CLKSEL clocks follow their parents' rates, divided by a divisor */
715 clk->rate = new_parent->rate;
718 clk->rate /= parent_div;
720 pr_debug("clock: set parent of %s to %s (new rate %ld)\n",
721 clk->name, clk->parent->name, clk->rate);
723 if (unlikely(clk->flags & RATE_PROPAGATES))
729 /*-------------------------------------------------------------------------
730 * Omap2 clock reset and init functions
731 *-------------------------------------------------------------------------*/
733 #ifdef CONFIG_OMAP_RESET_CLOCKS
734 void omap2_clk_disable_unused(struct clk *clk)
738 v = (clk->flags & INVERT_ENABLE) ? (1 << clk->enable_bit) : 0;
740 regval32 = cm_read_reg(clk->enable_reg);
741 if ((regval32 & (1 << clk->enable_bit)) == v)
744 printk(KERN_INFO "Disabling unused clock \"%s\"\n", clk->name);
745 _omap2_clk_disable(clk);