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.
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/device.h>
25 #include <linux/list.h>
26 #include <linux/errno.h>
27 #include <linux/delay.h>
28 #include <linux/clk.h>
32 #include <asm/arch/clock.h>
33 #include <asm/arch/sram.h>
34 #include <asm/div64.h>
40 #include "prm_regbits_24xx.h"
42 #include "cm_regbits_24xx.h"
46 #define MAX_PLL_LOCK_WAIT 100000
50 /*-------------------------------------------------------------------------
51 * Omap2 specific clock functions
52 *-------------------------------------------------------------------------*/
54 u8 mask_to_shift(u32 mask)
60 * omap2_init_clksel_parent - set a clksel clk's parent field from the hardware
61 * @clk: OMAP clock struct ptr to use
63 * Given a pointer to a source-selectable struct clk, read the hardware
64 * register and determine what its parent is currently set to. Update the
65 * clk->parent field with the appropriate clk ptr.
67 void omap2_init_clksel_parent(struct clk *clk)
69 const struct clksel *clks;
70 const struct clksel_rate *clkr;
76 /* XXX Should be __raw_readl for non-CM 3430 clocks ? */
77 r = cm_read_reg(clk->clksel_reg) & clk->clksel_mask;
78 r >>= mask_to_shift(clk->clksel_mask);
80 for (clks = clk->clksel; clks->parent && !found; clks++) {
81 for (clkr = clks->rates; clkr->div && !found; clkr++) {
82 if ((clkr->flags & cpu_mask) && (clkr->val == r)) {
83 if (clk->parent != clks->parent) {
84 pr_debug("clock: inited %s parent "
86 clk->name, clks->parent->name,
87 ((clk->parent->name) ?
88 clk->parent->name : "NULL"));
89 clk->parent = clks->parent;
97 printk(KERN_ERR "clock: init parent: could not find "
98 "regval %0x for clock %s\n", r, clk->name);
103 /* Returns the DPLL rate */
104 u32 omap2_get_dpll_rate(struct clk *clk)
107 u32 dpll_mult, dpll_div, dpll;
108 const struct dpll_data *dd;
111 /* REVISIT: What do we return on error? */
115 dpll = cm_read_reg(dd->mult_div1_reg);
116 dpll_mult = dpll & dd->mult_mask;
117 dpll_mult >>= mask_to_shift(dd->mult_mask);
118 dpll_div = dpll & dd->div1_mask;
119 dpll_div >>= mask_to_shift(dd->div1_mask);
121 dpll_clk = (long long)clk->parent->rate * dpll_mult;
122 do_div(dpll_clk, dpll_div + 1);
128 * Used for clocks that have the same value as the parent clock,
129 * divided by some factor
131 void omap2_fixed_divisor_recalc(struct clk *clk)
133 WARN_ON(!clk->fixed_div);
135 clk->rate = clk->parent->rate / clk->fixed_div;
137 if (clk->flags & RATE_PROPAGATES)
142 * omap2_wait_clock_ready - wait for PLL to lock
144 * Returns 1 if the PLL locked, 0 if it failed to lock.
146 int omap2_wait_clock_ready(void __iomem *reg, u32 cval, const char *name)
151 while (!(cm_read_reg(reg) & cval)) {
154 if (i == MAX_PLL_LOCK_WAIT) {
155 printk(KERN_ERR "Clock %s didn't lock in %d tries\n",
156 name, MAX_PLL_LOCK_WAIT);
162 pr_debug("Clock %s stable after %d loops\n", name, i);
164 return (i < MAX_PLL_LOCK_WAIT) ? 1 : 0;
168 static void omap2_clk_wait_ready(struct clk *clk)
170 void __iomem *reg, *other_reg, *st_reg;
173 reg = clk->enable_reg;
174 if (reg == OMAP_CM_REGADDR(CORE_MOD, CM_FCLKEN1) ||
175 reg == OMAP_CM_REGADDR(CORE_MOD, OMAP24XX_CM_FCLKEN2))
176 other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x10); /* CM_ICLKEN* */
177 else if (reg == OMAP_CM_REGADDR(CORE_MOD, CM_ICLKEN1) ||
178 reg == OMAP_CM_REGADDR(CORE_MOD, CM_ICLKEN2))
179 other_reg = (void __iomem *)(((u32)reg & ~0xf0) | 0x00); /* CM_FCLKEN* */
183 /* No check for DSS or cam clocks */
184 if (((u32)reg & 0x0f) == 0) { /* CM_{F,I}CLKEN1 */
185 if (clk->enable_bit == OMAP24XX_EN_DSS2_SHIFT ||
186 clk->enable_bit == OMAP24XX_EN_DSS1_SHIFT ||
187 clk->enable_bit == OMAP24XX_EN_CAM_SHIFT)
191 /* Check if both functional and interface clocks
193 bit = 1 << clk->enable_bit;
194 if (!(cm_read_reg(other_reg) & bit))
196 st_reg = (void __iomem *)(((u32)other_reg & ~0xf0) | 0x20); /* CM_IDLEST* */
198 omap2_wait_clock_ready(st_reg, bit, clk->name);
201 /* Enables clock without considering parent dependencies or use count
202 * REVISIT: Maybe change this to use clk->enable like on omap1?
204 int _omap2_clk_enable(struct clk *clk)
208 if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK))
212 return clk->enable(clk);
214 if (unlikely(clk->enable_reg == 0)) {
215 printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
220 regval32 = cm_read_reg(clk->enable_reg);
221 regval32 |= (1 << clk->enable_bit);
222 cm_write_reg(regval32, clk->enable_reg);
225 omap2_clk_wait_ready(clk);
230 /* Disables clock without considering parent dependencies or use count */
231 void _omap2_clk_disable(struct clk *clk)
235 if (clk->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK))
243 if (clk->enable_reg == 0) {
245 * 'Independent' here refers to a clock which is not
246 * controlled by its parent.
248 printk(KERN_ERR "clock: clk_disable called on independent "
249 "clock %s which has no enable_reg\n", clk->name);
253 regval32 = cm_read_reg(clk->enable_reg);
254 regval32 &= ~(1 << clk->enable_bit);
255 cm_write_reg(regval32, clk->enable_reg);
259 void omap2_clk_disable(struct clk *clk)
261 if (clk->usecount > 0 && !(--clk->usecount)) {
262 _omap2_clk_disable(clk);
263 if (likely((u32)clk->parent))
264 omap2_clk_disable(clk->parent);
268 int omap2_clk_enable(struct clk *clk)
272 if (clk->usecount++ == 0) {
273 if (likely((u32)clk->parent))
274 ret = omap2_clk_enable(clk->parent);
276 if (unlikely(ret != 0)) {
281 ret = _omap2_clk_enable(clk);
283 if (unlikely(ret != 0) && clk->parent) {
284 omap2_clk_disable(clk->parent);
293 * Used for clocks that are part of CLKSEL_xyz governed clocks.
294 * REVISIT: Maybe change to use clk->enable() functions like on omap1?
296 void omap2_clksel_recalc(struct clk *clk)
300 pr_debug("clock: recalc'ing clksel clk %s\n", clk->name);
302 div = omap2_clksel_get_divisor(clk);
306 if (unlikely(clk->rate == clk->parent->rate / div))
308 clk->rate = clk->parent->rate / div;
310 pr_debug("clock: new clock rate is %ld (div %d)\n", clk->rate, div);
312 if (unlikely(clk->flags & RATE_PROPAGATES))
317 * omap2_get_clksel_by_parent - return clksel struct for a given clk & parent
318 * @clk: OMAP struct clk ptr to inspect
319 * @src_clk: OMAP struct clk ptr of the parent clk to search for
321 * Scan the struct clksel array associated with the clock to find
322 * the element associated with the supplied parent clock address.
323 * Returns a pointer to the struct clksel on success or NULL on error.
325 const struct clksel *omap2_get_clksel_by_parent(struct clk *clk,
328 const struct clksel *clks;
333 for (clks = clk->clksel; clks->parent; clks++) {
334 if (clks->parent == src_clk)
335 break; /* Found the requested parent */
339 printk(KERN_ERR "clock: Could not find parent clock %s in "
340 "clksel array of clock %s\n", src_clk->name,
349 * omap2_clksel_round_rate_div - find divisor for the given clock and rate
350 * @clk: OMAP struct clk to use
351 * @target_rate: desired clock rate
352 * @new_div: ptr to where we should store the divisor
354 * Finds 'best' divider value in an array based on the source and target
355 * rates. The divider array must be sorted with smallest divider first.
356 * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
357 * they are only settable as part of virtual_prcm set.
359 * Returns the rounded clock rate or returns 0xffffffff on error.
361 u32 omap2_clksel_round_rate_div(struct clk *clk, unsigned long target_rate,
364 unsigned long test_rate;
365 const struct clksel *clks;
366 const struct clksel_rate *clkr;
369 printk(KERN_INFO "clock: clksel_round_rate_div: %s target_rate %ld\n",
370 clk->name, target_rate);
374 clks = omap2_get_clksel_by_parent(clk, clk->parent);
378 for (clkr = clks->rates; clkr->div; clkr++) {
379 if (!(clkr->flags & cpu_mask))
383 if (clkr->div <= last_div)
384 printk(KERN_ERR "clock: clksel_rate table not sorted "
385 "for clock %s", clk->name);
387 last_div = clkr->div;
389 test_rate = clk->parent->rate / clkr->div;
391 if (test_rate <= target_rate)
392 break; /* found it */
396 printk(KERN_ERR "clock: Could not find divisor for target "
397 "rate %ld for clock %s parent %s\n", target_rate,
398 clk->name, clk->parent->name);
402 *new_div = clkr->div;
404 printk(KERN_INFO "clock: new_div = %d, new_rate = %ld\n", *new_div,
405 (clk->parent->rate / clkr->div));
407 return (clk->parent->rate / clkr->div);
411 * omap2_clksel_round_rate - find rounded rate for the given clock and rate
412 * @clk: OMAP struct clk to use
413 * @target_rate: desired clock rate
415 * Compatibility wrapper for OMAP clock framework
416 * Finds best target rate based on the source clock and possible dividers.
417 * rates. The divider array must be sorted with smallest divider first.
418 * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
419 * they are only settable as part of virtual_prcm set.
421 * Returns the rounded clock rate or returns 0xffffffff on error.
423 long omap2_clksel_round_rate(struct clk *clk, unsigned long target_rate)
427 return omap2_clksel_round_rate_div(clk, target_rate, &new_div);
431 /* Given a clock and a rate apply a clock specific rounding function */
432 long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
434 if (clk->round_rate != 0)
435 return clk->round_rate(clk, rate);
437 if (clk->flags & RATE_FIXED)
438 printk(KERN_ERR "clock: generic omap2_clk_round_rate called "
439 "on fixed-rate clock %s\n", clk->name);
445 * omap2_clksel_to_divisor() - turn clksel field value into integer divider
446 * @clk: OMAP struct clk to use
447 * @field_val: register field value to find
449 * Given a struct clk of a rate-selectable clksel clock, and a register field
450 * value to search for, find the corresponding clock divisor. The register
451 * field value should be pre-masked and shifted down so the LSB is at bit 0
452 * before calling. Returns 0 on error
454 u32 omap2_clksel_to_divisor(struct clk *clk, u32 field_val)
456 const struct clksel *clks;
457 const struct clksel_rate *clkr;
459 clks = omap2_get_clksel_by_parent(clk, clk->parent);
463 for (clkr = clks->rates; clkr->div; clkr++) {
464 if ((clkr->flags & cpu_mask) && (clkr->val == field_val))
469 printk(KERN_ERR "clock: Could not find fieldval %d for "
470 "clock %s parent %s\n", field_val, clk->name,
479 * omap2_divisor_to_clksel() - turn clksel integer divisor into a field value
480 * @clk: OMAP struct clk to use
481 * @div: integer divisor to search for
483 * Given a struct clk of a rate-selectable clksel clock, and a clock divisor,
484 * find the corresponding register field value. The return register value is
485 * the value before left-shifting. Returns 0xffffffff on error
487 u32 omap2_divisor_to_clksel(struct clk *clk, u32 div)
489 const struct clksel *clks;
490 const struct clksel_rate *clkr;
492 /* should never happen */
495 clks = omap2_get_clksel_by_parent(clk, clk->parent);
499 for (clkr = clks->rates; clkr->div; clkr++) {
500 if ((clkr->flags & cpu_mask) && (clkr->div == div))
505 printk(KERN_ERR "clock: Could not find divisor %d for "
506 "clock %s parent %s\n", div, clk->name,
515 * omap2_get_clksel - find clksel register addr & field mask for a clk
516 * @clk: struct clk to use
517 * @field_mask: ptr to u32 to store the register field mask
519 * Returns the address of the clksel register upon success or NULL on error.
521 void __iomem *omap2_get_clksel(struct clk *clk, u32 *field_mask)
523 if (unlikely((clk->clksel_reg == 0) || (clk->clksel_mask == 0)))
526 *field_mask = clk->clksel_mask;
528 return clk->clksel_reg;
532 * omap2_clksel_get_divisor - get current divider applied to parent clock.
533 * @clk: OMAP struct clk to use.
535 * Returns the integer divisor upon success or 0 on error.
537 u32 omap2_clksel_get_divisor(struct clk *clk)
539 u32 field_mask, field_val;
540 void __iomem *div_addr;
542 div_addr = omap2_get_clksel(clk, &field_mask);
546 field_val = cm_read_reg(div_addr) & field_mask;
547 field_val >>= mask_to_shift(field_mask);
549 return omap2_clksel_to_divisor(clk, field_val);
552 int omap2_clksel_set_rate(struct clk *clk, unsigned long rate)
554 u32 field_mask, field_val, reg_val, validrate, new_div = 0;
555 void __iomem *div_addr;
557 validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
558 if (validrate != rate)
561 div_addr = omap2_get_clksel(clk, &field_mask);
565 field_val = omap2_divisor_to_clksel(clk, new_div);
569 reg_val = cm_read_reg(div_addr);
570 reg_val &= ~field_mask;
571 reg_val |= (field_val << mask_to_shift(field_mask));
572 cm_write_reg(reg_val, div_addr);
575 clk->rate = clk->parent->rate / new_div;
577 if (clk->flags & DELAYED_APP) {
578 prm_write_reg(OMAP24XX_VALID_CONFIG, OMAP24XX_PRCM_CLKCFG_CTRL);
586 /* Set the clock rate for a clock source */
587 int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
591 pr_debug("clock: set_rate for clock %s to rate %ld\n", clk->name, rate);
593 /* CONFIG_PARTICIPANT clocks are changed only in sets via the
594 rate table mechanism, driven by mpu_speed */
595 if (clk->flags & CONFIG_PARTICIPANT)
598 /* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
599 if (clk->set_rate != 0)
600 ret = clk->set_rate(clk, rate);
602 if (unlikely(ret == 0 && (clk->flags & RATE_PROPAGATES)))
609 * Converts encoded control register address into a full address
610 * On error, *src_addr will be returned as 0.
612 static u32 omap2_clksel_get_src_field(void __iomem **src_addr,
613 struct clk *src_clk, u32 *field_mask,
614 struct clk *clk, u32 *parent_div)
616 const struct clksel *clks;
617 const struct clksel_rate *clkr;
622 clks = omap2_get_clksel_by_parent(clk, src_clk);
626 for (clkr = clks->rates; clkr->div; clkr++) {
627 if (clkr->flags & (cpu_mask | DEFAULT_RATE))
628 break; /* Found the default rate for this platform */
632 printk(KERN_ERR "clock: Could not find default rate for "
633 "clock %s parent %s\n", clk->name,
634 src_clk->parent->name);
638 /* Should never happen. Add a clksel mask to the struct clk. */
639 WARN_ON(clk->clksel_mask == 0);
641 *field_mask = clk->clksel_mask;
642 *src_addr = clk->clksel_reg;
643 *parent_div = clkr->div;
648 int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
650 void __iomem *src_addr;
651 u32 field_val, field_mask, reg_val, parent_div;
653 if (unlikely(clk->flags & CONFIG_PARTICIPANT))
659 field_val = omap2_clksel_get_src_field(&src_addr, new_parent,
660 &field_mask, clk, &parent_div);
664 if (clk->usecount > 0)
665 _omap2_clk_disable(clk);
667 /* Set new source value (previous dividers if any in effect) */
668 reg_val = __raw_readl(src_addr) & ~field_mask;
669 reg_val |= (field_val << mask_to_shift(field_mask));
670 __raw_writel(reg_val, src_addr);
673 if (clk->flags & DELAYED_APP) {
674 prm_write_reg(OMAP24XX_VALID_CONFIG,
675 OMAP24XX_PRCM_CLKCFG_CTRL);
679 if (clk->usecount > 0)
680 _omap2_clk_enable(clk);
682 clk->parent = new_parent;
684 /* CLKSEL clocks follow their parents' rates, divided by a divisor */
685 clk->rate = new_parent->rate;
688 clk->rate /= parent_div;
690 pr_debug("clock: set parent of %s to %s (new rate %ld)\n",
691 clk->name, clk->parent->name, clk->rate);
693 if (unlikely(clk->flags & RATE_PROPAGATES))
699 /*-------------------------------------------------------------------------
700 * Omap2 clock reset and init functions
701 *-------------------------------------------------------------------------*/
703 #ifdef CONFIG_OMAP_RESET_CLOCKS
704 void __init omap2_clk_disable_unused(struct clk *clk)
708 regval32 = cm_read_reg(clk->enable_reg);
709 if ((regval32 & (1 << clk->enable_bit)) == 0)
712 printk(KERN_INFO "Disabling unused clock \"%s\"\n", clk->name);
713 _omap2_clk_disable(clk);