2 * OMAP3/4 - specific DPLL control functions
4 * Copyright (C) 2009-2010 Texas Instruments, Inc.
5 * Copyright (C) 2009-2010 Nokia Corporation
7 * Written by Paul Walmsley
8 * Testing and integration fixes by Jouni Högander
10 * 36xx support added by Vishwanath BS, Richard Woodruff, and Nishanth
13 * Parts of this code are based on code written by
14 * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2 as
18 * published by the Free Software Foundation.
21 #include <linux/kernel.h>
22 #include <linux/device.h>
23 #include <linux/list.h>
24 #include <linux/errno.h>
25 #include <linux/delay.h>
26 #include <linux/clk.h>
28 #include <linux/bitops.h>
29 #include <linux/clkdev.h>
32 #include "clockdomain.h"
34 #include "cm2xxx_3xxx.h"
35 #include "cm-regbits-34xx.h"
37 /* CM_AUTOIDLE_PLL*.AUTO_* bit values */
38 #define DPLL_AUTOIDLE_DISABLE 0x0
39 #define DPLL_AUTOIDLE_LOW_POWER_STOP 0x1
41 #define MAX_DPLL_WAIT_TRIES 1000000
43 /* Private functions */
45 /* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
46 static void _omap3_dpll_write_clken(struct clk_hw_omap
*clk
, u8 clken_bits
)
48 const struct dpll_data
*dd
;
53 v
= omap2_clk_readl(clk
, dd
->control_reg
);
54 v
&= ~dd
->enable_mask
;
55 v
|= clken_bits
<< __ffs(dd
->enable_mask
);
56 omap2_clk_writel(v
, clk
, dd
->control_reg
);
59 /* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
60 static int _omap3_wait_dpll_status(struct clk_hw_omap
*clk
, u8 state
)
62 const struct dpll_data
*dd
;
68 clk_name
= __clk_get_name(clk
->hw
.clk
);
70 state
<<= __ffs(dd
->idlest_mask
);
72 while (((omap2_clk_readl(clk
, dd
->idlest_reg
) & dd
->idlest_mask
)
73 != state
) && i
< MAX_DPLL_WAIT_TRIES
) {
78 if (i
== MAX_DPLL_WAIT_TRIES
) {
79 printk(KERN_ERR
"clock: %s failed transition to '%s'\n",
80 clk_name
, (state
) ? "locked" : "bypassed");
82 pr_debug("clock: %s transition to '%s' in %d loops\n",
83 clk_name
, (state
) ? "locked" : "bypassed", i
);
91 /* From 3430 TRM ES2 4.7.6.2 */
92 static u16
_omap3_dpll_compute_freqsel(struct clk_hw_omap
*clk
, u8 n
)
97 fint
= __clk_get_rate(clk
->dpll_data
->clk_ref
) / n
;
99 pr_debug("clock: fint is %lu\n", fint
);
101 if (fint
>= 750000 && fint
<= 1000000)
103 else if (fint
> 1000000 && fint
<= 1250000)
105 else if (fint
> 1250000 && fint
<= 1500000)
107 else if (fint
> 1500000 && fint
<= 1750000)
109 else if (fint
> 1750000 && fint
<= 2100000)
111 else if (fint
> 7500000 && fint
<= 10000000)
113 else if (fint
> 10000000 && fint
<= 12500000)
115 else if (fint
> 12500000 && fint
<= 15000000)
117 else if (fint
> 15000000 && fint
<= 17500000)
119 else if (fint
> 17500000 && fint
<= 21000000)
122 pr_debug("clock: unknown freqsel setting for %d\n", n
);
128 * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
129 * @clk: pointer to a DPLL struct clk
131 * Instructs a non-CORE DPLL to lock. Waits for the DPLL to report
132 * readiness before returning. Will save and restore the DPLL's
133 * autoidle state across the enable, per the CDP code. If the DPLL
134 * locked successfully, return 0; if the DPLL did not lock in the time
135 * allotted, or DPLL3 was passed in, return -EINVAL.
137 static int _omap3_noncore_dpll_lock(struct clk_hw_omap
*clk
)
139 const struct dpll_data
*dd
;
144 pr_debug("clock: locking DPLL %s\n", __clk_get_name(clk
->hw
.clk
));
147 state
<<= __ffs(dd
->idlest_mask
);
149 /* Check if already locked */
150 if ((omap2_clk_readl(clk
, dd
->idlest_reg
) & dd
->idlest_mask
) == state
)
153 ai
= omap3_dpll_autoidle_read(clk
);
156 omap3_dpll_deny_idle(clk
);
158 _omap3_dpll_write_clken(clk
, DPLL_LOCKED
);
160 r
= _omap3_wait_dpll_status(clk
, 1);
163 omap3_dpll_allow_idle(clk
);
170 * _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
171 * @clk: pointer to a DPLL struct clk
173 * Instructs a non-CORE DPLL to enter low-power bypass mode. In
174 * bypass mode, the DPLL's rate is set equal to its parent clock's
175 * rate. Waits for the DPLL to report readiness before returning.
176 * Will save and restore the DPLL's autoidle state across the enable,
177 * per the CDP code. If the DPLL entered bypass mode successfully,
178 * return 0; if the DPLL did not enter bypass in the time allotted, or
179 * DPLL3 was passed in, or the DPLL does not support low-power bypass,
182 static int _omap3_noncore_dpll_bypass(struct clk_hw_omap
*clk
)
187 if (!(clk
->dpll_data
->modes
& (1 << DPLL_LOW_POWER_BYPASS
)))
190 pr_debug("clock: configuring DPLL %s for low-power bypass\n",
191 __clk_get_name(clk
->hw
.clk
));
193 ai
= omap3_dpll_autoidle_read(clk
);
195 _omap3_dpll_write_clken(clk
, DPLL_LOW_POWER_BYPASS
);
197 r
= _omap3_wait_dpll_status(clk
, 0);
200 omap3_dpll_allow_idle(clk
);
206 * _omap3_noncore_dpll_stop - instruct a DPLL to stop
207 * @clk: pointer to a DPLL struct clk
209 * Instructs a non-CORE DPLL to enter low-power stop. Will save and
210 * restore the DPLL's autoidle state across the stop, per the CDP
211 * code. If DPLL3 was passed in, or the DPLL does not support
212 * low-power stop, return -EINVAL; otherwise, return 0.
214 static int _omap3_noncore_dpll_stop(struct clk_hw_omap
*clk
)
218 if (!(clk
->dpll_data
->modes
& (1 << DPLL_LOW_POWER_STOP
)))
221 pr_debug("clock: stopping DPLL %s\n", __clk_get_name(clk
->hw
.clk
));
223 ai
= omap3_dpll_autoidle_read(clk
);
225 _omap3_dpll_write_clken(clk
, DPLL_LOW_POWER_STOP
);
228 omap3_dpll_allow_idle(clk
);
234 * _lookup_dco - Lookup DCO used by j-type DPLL
235 * @clk: pointer to a DPLL struct clk
236 * @dco: digital control oscillator selector
237 * @m: DPLL multiplier to set
238 * @n: DPLL divider to set
240 * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
242 * XXX This code is not needed for 3430/AM35xx; can it be optimized
243 * out in non-multi-OMAP builds for those chips?
245 static void _lookup_dco(struct clk_hw_omap
*clk
, u8
*dco
, u16 m
, u8 n
)
247 unsigned long fint
, clkinp
; /* watch out for overflow */
249 clkinp
= __clk_get_rate(__clk_get_parent(clk
->hw
.clk
));
250 fint
= (clkinp
/ n
) * m
;
252 if (fint
< 1000000000)
259 * _lookup_sddiv - Calculate sigma delta divider for j-type DPLL
260 * @clk: pointer to a DPLL struct clk
261 * @sd_div: target sigma-delta divider
262 * @m: DPLL multiplier to set
263 * @n: DPLL divider to set
265 * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
267 * XXX This code is not needed for 3430/AM35xx; can it be optimized
268 * out in non-multi-OMAP builds for those chips?
270 static void _lookup_sddiv(struct clk_hw_omap
*clk
, u8
*sd_div
, u16 m
, u8 n
)
272 unsigned long clkinp
, sd
; /* watch out for overflow */
275 clkinp
= __clk_get_rate(__clk_get_parent(clk
->hw
.clk
));
278 * target sigma-delta to near 250MHz
279 * sd = ceil[(m/(n+1)) * (clkinp_MHz / 250)]
281 clkinp
/= 100000; /* shift from MHz to 10*Hz for 38.4 and 19.2 */
282 mod1
= (clkinp
* m
) % (250 * n
);
283 sd
= (clkinp
* m
) / (250 * n
);
293 * _omap3_noncore_dpll_program - set non-core DPLL M,N values directly
294 * @clk: struct clk * of DPLL to set
295 * @freqsel: FREQSEL value to set
297 * Program the DPLL with the last M, N values calculated, and wait for
298 * the DPLL to lock. Returns -EINVAL upon error, or 0 upon success.
300 static int omap3_noncore_dpll_program(struct clk_hw_omap
*clk
, u16 freqsel
)
302 struct dpll_data
*dd
= clk
->dpll_data
;
306 /* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
307 _omap3_noncore_dpll_bypass(clk
);
310 * Set jitter correction. Jitter correction applicable for OMAP343X
311 * only since freqsel field is no longer present on other devices.
313 if (cpu_is_omap343x()) {
314 v
= omap2_clk_readl(clk
, dd
->control_reg
);
315 v
&= ~dd
->freqsel_mask
;
316 v
|= freqsel
<< __ffs(dd
->freqsel_mask
);
317 omap2_clk_writel(v
, clk
, dd
->control_reg
);
320 /* Set DPLL multiplier, divider */
321 v
= omap2_clk_readl(clk
, dd
->mult_div1_reg
);
323 /* Handle Duty Cycle Correction */
325 if (dd
->last_rounded_rate
>= dd
->dcc_rate
)
326 v
|= dd
->dcc_mask
; /* Enable DCC */
328 v
&= ~dd
->dcc_mask
; /* Disable DCC */
331 v
&= ~(dd
->mult_mask
| dd
->div1_mask
);
332 v
|= dd
->last_rounded_m
<< __ffs(dd
->mult_mask
);
333 v
|= (dd
->last_rounded_n
- 1) << __ffs(dd
->div1_mask
);
335 /* Configure dco and sd_div for dplls that have these fields */
337 _lookup_dco(clk
, &dco
, dd
->last_rounded_m
, dd
->last_rounded_n
);
338 v
&= ~(dd
->dco_mask
);
339 v
|= dco
<< __ffs(dd
->dco_mask
);
341 if (dd
->sddiv_mask
) {
342 _lookup_sddiv(clk
, &sd_div
, dd
->last_rounded_m
,
344 v
&= ~(dd
->sddiv_mask
);
345 v
|= sd_div
<< __ffs(dd
->sddiv_mask
);
348 omap2_clk_writel(v
, clk
, dd
->mult_div1_reg
);
350 /* Set 4X multiplier and low-power mode */
351 if (dd
->m4xen_mask
|| dd
->lpmode_mask
) {
352 v
= omap2_clk_readl(clk
, dd
->control_reg
);
354 if (dd
->m4xen_mask
) {
355 if (dd
->last_rounded_m4xen
)
358 v
&= ~dd
->m4xen_mask
;
361 if (dd
->lpmode_mask
) {
362 if (dd
->last_rounded_lpmode
)
363 v
|= dd
->lpmode_mask
;
365 v
&= ~dd
->lpmode_mask
;
368 omap2_clk_writel(v
, clk
, dd
->control_reg
);
371 /* We let the clock framework set the other output dividers later */
373 /* REVISIT: Set ramp-up delay? */
375 _omap3_noncore_dpll_lock(clk
);
380 /* Public functions */
383 * omap3_dpll_recalc - recalculate DPLL rate
384 * @clk: DPLL struct clk
386 * Recalculate and propagate the DPLL rate.
388 unsigned long omap3_dpll_recalc(struct clk_hw
*hw
, unsigned long parent_rate
)
390 struct clk_hw_omap
*clk
= to_clk_hw_omap(hw
);
392 return omap2_get_dpll_rate(clk
);
395 /* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
398 * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
399 * @clk: pointer to a DPLL struct clk
401 * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
402 * The choice of modes depends on the DPLL's programmed rate: if it is
403 * the same as the DPLL's parent clock, it will enter bypass;
404 * otherwise, it will enter lock. This code will wait for the DPLL to
405 * indicate readiness before returning, unless the DPLL takes too long
406 * to enter the target state. Intended to be used as the struct clk's
407 * enable function. If DPLL3 was passed in, or the DPLL does not
408 * support low-power stop, or if the DPLL took too long to enter
409 * bypass or lock, return -EINVAL; otherwise, return 0.
411 int omap3_noncore_dpll_enable(struct clk_hw
*hw
)
413 struct clk_hw_omap
*clk
= to_clk_hw_omap(hw
);
415 struct dpll_data
*dd
;
423 r
= clkdm_clk_enable(clk
->clkdm
, hw
->clk
);
426 "%s: could not enable %s's clockdomain %s: %d\n",
427 __func__
, __clk_get_name(hw
->clk
),
428 clk
->clkdm
->name
, r
);
433 parent
= __clk_get_parent(hw
->clk
);
435 if (__clk_get_rate(hw
->clk
) == __clk_get_rate(dd
->clk_bypass
)) {
436 WARN_ON(parent
!= dd
->clk_bypass
);
437 r
= _omap3_noncore_dpll_bypass(clk
);
439 WARN_ON(parent
!= dd
->clk_ref
);
440 r
= _omap3_noncore_dpll_lock(clk
);
447 * omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop
448 * @clk: pointer to a DPLL struct clk
450 * Instructs a non-CORE DPLL to enter low-power stop. This function is
451 * intended for use in struct clkops. No return value.
453 void omap3_noncore_dpll_disable(struct clk_hw
*hw
)
455 struct clk_hw_omap
*clk
= to_clk_hw_omap(hw
);
457 _omap3_noncore_dpll_stop(clk
);
459 clkdm_clk_disable(clk
->clkdm
, hw
->clk
);
463 /* Non-CORE DPLL rate set code */
466 * omap3_noncore_dpll_set_rate - set non-core DPLL rate
467 * @clk: struct clk * of DPLL to set
468 * @rate: rounded target rate
470 * Set the DPLL CLKOUT to the target rate. If the DPLL can enter
471 * low-power bypass, and the target rate is the bypass source clock
472 * rate, then configure the DPLL for bypass. Otherwise, round the
473 * target rate if it hasn't been done already, then program and lock
474 * the DPLL. Returns -EINVAL upon error, or 0 upon success.
476 int omap3_noncore_dpll_set_rate(struct clk_hw
*hw
, unsigned long rate
,
477 unsigned long parent_rate
)
479 struct clk_hw_omap
*clk
= to_clk_hw_omap(hw
);
480 struct clk
*new_parent
= NULL
;
482 struct dpll_data
*dd
;
492 if (__clk_get_rate(dd
->clk_bypass
) == rate
&&
493 (dd
->modes
& (1 << DPLL_LOW_POWER_BYPASS
))) {
494 pr_debug("%s: %s: set rate: entering bypass.\n",
495 __func__
, __clk_get_name(hw
->clk
));
497 __clk_prepare(dd
->clk_bypass
);
498 clk_enable(dd
->clk_bypass
);
499 ret
= _omap3_noncore_dpll_bypass(clk
);
501 new_parent
= dd
->clk_bypass
;
502 clk_disable(dd
->clk_bypass
);
503 __clk_unprepare(dd
->clk_bypass
);
505 __clk_prepare(dd
->clk_ref
);
506 clk_enable(dd
->clk_ref
);
508 if (dd
->last_rounded_rate
!= rate
)
509 rate
= __clk_round_rate(hw
->clk
, rate
);
511 if (dd
->last_rounded_rate
== 0)
514 /* Freqsel is available only on OMAP343X devices */
515 if (cpu_is_omap343x()) {
516 freqsel
= _omap3_dpll_compute_freqsel(clk
,
521 pr_debug("%s: %s: set rate: locking rate to %lu.\n",
522 __func__
, __clk_get_name(hw
->clk
), rate
);
524 ret
= omap3_noncore_dpll_program(clk
, freqsel
);
526 new_parent
= dd
->clk_ref
;
527 clk_disable(dd
->clk_ref
);
528 __clk_unprepare(dd
->clk_ref
);
531 * FIXME - this is all wrong. common code handles reparenting and
532 * migrating prepare/enable counts. dplls should be a multiplexer
533 * clock and this should be a set_parent operation so that all of that
534 * stuff is inherited for free
537 if (!ret
&& clk_get_parent(hw
->clk
) != new_parent
)
538 __clk_reparent(hw
->clk
, new_parent
);
543 /* DPLL autoidle read/set code */
546 * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
547 * @clk: struct clk * of the DPLL to read
549 * Return the DPLL's autoidle bits, shifted down to bit 0. Returns
550 * -EINVAL if passed a null pointer or if the struct clk does not
551 * appear to refer to a DPLL.
553 u32
omap3_dpll_autoidle_read(struct clk_hw_omap
*clk
)
555 const struct dpll_data
*dd
;
558 if (!clk
|| !clk
->dpll_data
)
563 if (!dd
->autoidle_reg
)
566 v
= omap2_clk_readl(clk
, dd
->autoidle_reg
);
567 v
&= dd
->autoidle_mask
;
568 v
>>= __ffs(dd
->autoidle_mask
);
574 * omap3_dpll_allow_idle - enable DPLL autoidle bits
575 * @clk: struct clk * of the DPLL to operate on
577 * Enable DPLL automatic idle control. This automatic idle mode
578 * switching takes effect only when the DPLL is locked, at least on
579 * OMAP3430. The DPLL will enter low-power stop when its downstream
580 * clocks are gated. No return value.
582 void omap3_dpll_allow_idle(struct clk_hw_omap
*clk
)
584 const struct dpll_data
*dd
;
587 if (!clk
|| !clk
->dpll_data
)
592 if (!dd
->autoidle_reg
)
596 * REVISIT: CORE DPLL can optionally enter low-power bypass
597 * by writing 0x5 instead of 0x1. Add some mechanism to
598 * optionally enter this mode.
600 v
= omap2_clk_readl(clk
, dd
->autoidle_reg
);
601 v
&= ~dd
->autoidle_mask
;
602 v
|= DPLL_AUTOIDLE_LOW_POWER_STOP
<< __ffs(dd
->autoidle_mask
);
603 omap2_clk_writel(v
, clk
, dd
->autoidle_reg
);
608 * omap3_dpll_deny_idle - prevent DPLL from automatically idling
609 * @clk: struct clk * of the DPLL to operate on
611 * Disable DPLL automatic idle control. No return value.
613 void omap3_dpll_deny_idle(struct clk_hw_omap
*clk
)
615 const struct dpll_data
*dd
;
618 if (!clk
|| !clk
->dpll_data
)
623 if (!dd
->autoidle_reg
)
626 v
= omap2_clk_readl(clk
, dd
->autoidle_reg
);
627 v
&= ~dd
->autoidle_mask
;
628 v
|= DPLL_AUTOIDLE_DISABLE
<< __ffs(dd
->autoidle_mask
);
629 omap2_clk_writel(v
, clk
, dd
->autoidle_reg
);
633 /* Clock control for DPLL outputs */
635 /* Find the parent DPLL for the given clkoutx2 clock */
636 static struct clk_hw_omap
*omap3_find_clkoutx2_dpll(struct clk_hw
*hw
)
638 struct clk_hw_omap
*pclk
= NULL
;
641 /* Walk up the parents of clk, looking for a DPLL */
644 parent
= __clk_get_parent(hw
->clk
);
645 hw
= __clk_get_hw(parent
);
646 } while (hw
&& (__clk_get_flags(hw
->clk
) & CLK_IS_BASIC
));
649 pclk
= to_clk_hw_omap(hw
);
650 } while (pclk
&& !pclk
->dpll_data
);
652 /* clk does not have a DPLL as a parent? error in the clock data */
662 * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
663 * @clk: DPLL output struct clk
665 * Using parent clock DPLL data, look up DPLL state. If locked, set our
666 * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
668 unsigned long omap3_clkoutx2_recalc(struct clk_hw
*hw
,
669 unsigned long parent_rate
)
671 const struct dpll_data
*dd
;
674 struct clk_hw_omap
*pclk
= NULL
;
679 pclk
= omap3_find_clkoutx2_dpll(hw
);
684 dd
= pclk
->dpll_data
;
686 WARN_ON(!dd
->enable_mask
);
688 v
= omap2_clk_readl(pclk
, dd
->control_reg
) & dd
->enable_mask
;
689 v
>>= __ffs(dd
->enable_mask
);
690 if ((v
!= OMAP3XXX_EN_DPLL_LOCKED
) || (dd
->flags
& DPLL_J_TYPE
))
693 rate
= parent_rate
* 2;
697 int omap3_clkoutx2_set_rate(struct clk_hw
*hw
, unsigned long rate
,
698 unsigned long parent_rate
)
703 long omap3_clkoutx2_round_rate(struct clk_hw
*hw
, unsigned long rate
,
704 unsigned long *prate
)
706 const struct dpll_data
*dd
;
708 struct clk_hw_omap
*pclk
= NULL
;
713 pclk
= omap3_find_clkoutx2_dpll(hw
);
718 dd
= pclk
->dpll_data
;
720 /* TYPE J does not have a clkoutx2 */
721 if (dd
->flags
& DPLL_J_TYPE
) {
722 *prate
= __clk_round_rate(__clk_get_parent(pclk
->hw
.clk
), rate
);
726 WARN_ON(!dd
->enable_mask
);
728 v
= omap2_clk_readl(pclk
, dd
->control_reg
) & dd
->enable_mask
;
729 v
>>= __ffs(dd
->enable_mask
);
731 /* If in bypass, the rate is fixed to the bypass rate*/
732 if (v
!= OMAP3XXX_EN_DPLL_LOCKED
)
735 if (__clk_get_flags(hw
->clk
) & CLK_SET_RATE_PARENT
) {
736 unsigned long best_parent
;
738 best_parent
= (rate
/ 2);
739 *prate
= __clk_round_rate(__clk_get_parent(hw
->clk
),
746 /* OMAP3/4 non-CORE DPLL clkops */
747 const struct clk_hw_omap_ops clkhwops_omap3_dpll
= {
748 .allow_idle
= omap3_dpll_allow_idle
,
749 .deny_idle
= omap3_dpll_deny_idle
,