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>
31 #include <plat/clock.h>
35 #include "cm2xxx_3xxx.h"
36 #include "cm-regbits-34xx.h"
38 /* CM_AUTOIDLE_PLL*.AUTO_* bit values */
39 #define DPLL_AUTOIDLE_DISABLE 0x0
40 #define DPLL_AUTOIDLE_LOW_POWER_STOP 0x1
42 #define MAX_DPLL_WAIT_TRIES 1000000
44 /* Private functions */
46 /* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
47 static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits)
49 const struct dpll_data *dd;
54 v = __raw_readl(dd->control_reg);
55 v &= ~dd->enable_mask;
56 v |= clken_bits << __ffs(dd->enable_mask);
57 __raw_writel(v, dd->control_reg);
60 /* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
61 static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
63 const struct dpll_data *dd;
69 clk_name = __clk_get_name(clk);
71 state <<= __ffs(dd->idlest_mask);
73 while (((__raw_readl(dd->idlest_reg) & dd->idlest_mask) != state) &&
74 i < MAX_DPLL_WAIT_TRIES) {
79 if (i == MAX_DPLL_WAIT_TRIES) {
80 printk(KERN_ERR "clock: %s failed transition to '%s'\n",
81 clk_name, (state) ? "locked" : "bypassed");
83 pr_debug("clock: %s transition to '%s' in %d loops\n",
84 clk_name, (state) ? "locked" : "bypassed", i);
92 /* From 3430 TRM ES2 4.7.6.2 */
93 static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
98 fint = __clk_get_rate(clk->dpll_data->clk_ref) / n;
100 pr_debug("clock: fint is %lu\n", fint);
102 if (fint >= 750000 && fint <= 1000000)
104 else if (fint > 1000000 && fint <= 1250000)
106 else if (fint > 1250000 && fint <= 1500000)
108 else if (fint > 1500000 && fint <= 1750000)
110 else if (fint > 1750000 && fint <= 2100000)
112 else if (fint > 7500000 && fint <= 10000000)
114 else if (fint > 10000000 && fint <= 12500000)
116 else if (fint > 12500000 && fint <= 15000000)
118 else if (fint > 15000000 && fint <= 17500000)
120 else if (fint > 17500000 && fint <= 21000000)
123 pr_debug("clock: unknown freqsel setting for %d\n", n);
129 * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
130 * @clk: pointer to a DPLL struct clk
132 * Instructs a non-CORE DPLL to lock. Waits for the DPLL to report
133 * readiness before returning. Will save and restore the DPLL's
134 * autoidle state across the enable, per the CDP code. If the DPLL
135 * locked successfully, return 0; if the DPLL did not lock in the time
136 * allotted, or DPLL3 was passed in, return -EINVAL.
138 static int _omap3_noncore_dpll_lock(struct clk *clk)
140 const struct dpll_data *dd;
145 pr_debug("clock: locking DPLL %s\n", __clk_get_name(clk));
148 state <<= __ffs(dd->idlest_mask);
150 /* Check if already locked */
151 if ((__raw_readl(dd->idlest_reg) & dd->idlest_mask) == state)
154 ai = omap3_dpll_autoidle_read(clk);
157 omap3_dpll_deny_idle(clk);
159 _omap3_dpll_write_clken(clk, DPLL_LOCKED);
161 r = _omap3_wait_dpll_status(clk, 1);
164 omap3_dpll_allow_idle(clk);
171 * _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
172 * @clk: pointer to a DPLL struct clk
174 * Instructs a non-CORE DPLL to enter low-power bypass mode. In
175 * bypass mode, the DPLL's rate is set equal to its parent clock's
176 * rate. Waits for the DPLL to report readiness before returning.
177 * Will save and restore the DPLL's autoidle state across the enable,
178 * per the CDP code. If the DPLL entered bypass mode successfully,
179 * return 0; if the DPLL did not enter bypass in the time allotted, or
180 * DPLL3 was passed in, or the DPLL does not support low-power bypass,
183 static int _omap3_noncore_dpll_bypass(struct clk *clk)
188 if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
191 pr_debug("clock: configuring DPLL %s for low-power bypass\n",
192 __clk_get_name(clk));
194 ai = omap3_dpll_autoidle_read(clk);
196 _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);
198 r = _omap3_wait_dpll_status(clk, 0);
201 omap3_dpll_allow_idle(clk);
207 * _omap3_noncore_dpll_stop - instruct a DPLL to stop
208 * @clk: pointer to a DPLL struct clk
210 * Instructs a non-CORE DPLL to enter low-power stop. Will save and
211 * restore the DPLL's autoidle state across the stop, per the CDP
212 * code. If DPLL3 was passed in, or the DPLL does not support
213 * low-power stop, return -EINVAL; otherwise, return 0.
215 static int _omap3_noncore_dpll_stop(struct clk *clk)
219 if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
222 pr_debug("clock: stopping DPLL %s\n", __clk_get_name(clk));
224 ai = omap3_dpll_autoidle_read(clk);
226 _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);
229 omap3_dpll_allow_idle(clk);
235 * _lookup_dco - Lookup DCO used by j-type DPLL
236 * @clk: pointer to a DPLL struct clk
237 * @dco: digital control oscillator selector
238 * @m: DPLL multiplier to set
239 * @n: DPLL divider to set
241 * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
243 * XXX This code is not needed for 3430/AM35xx; can it be optimized
244 * out in non-multi-OMAP builds for those chips?
246 static void _lookup_dco(struct clk *clk, u8 *dco, u16 m, u8 n)
248 unsigned long fint, clkinp; /* watch out for overflow */
250 clkinp = __clk_get_rate(__clk_get_parent(clk));
251 fint = (clkinp / n) * m;
253 if (fint < 1000000000)
260 * _lookup_sddiv - Calculate sigma delta divider for j-type DPLL
261 * @clk: pointer to a DPLL struct clk
262 * @sd_div: target sigma-delta divider
263 * @m: DPLL multiplier to set
264 * @n: DPLL divider to set
266 * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
268 * XXX This code is not needed for 3430/AM35xx; can it be optimized
269 * out in non-multi-OMAP builds for those chips?
271 static void _lookup_sddiv(struct clk *clk, u8 *sd_div, u16 m, u8 n)
273 unsigned long clkinp, sd; /* watch out for overflow */
276 clkinp = __clk_get_rate(__clk_get_parent(clk));
279 * target sigma-delta to near 250MHz
280 * sd = ceil[(m/(n+1)) * (clkinp_MHz / 250)]
282 clkinp /= 100000; /* shift from MHz to 10*Hz for 38.4 and 19.2 */
283 mod1 = (clkinp * m) % (250 * n);
284 sd = (clkinp * m) / (250 * n);
294 * _omap3_noncore_dpll_program - set non-core DPLL M,N values directly
295 * @clk: struct clk * of DPLL to set
296 * @m: DPLL multiplier to set
297 * @n: DPLL divider to set
298 * @freqsel: FREQSEL value to set
300 * Program the DPLL with the supplied M, N values, and wait for the DPLL to
301 * lock.. Returns -EINVAL upon error, or 0 upon success.
303 static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
305 struct dpll_data *dd = clk->dpll_data;
309 /* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
310 _omap3_noncore_dpll_bypass(clk);
313 * Set jitter correction. No jitter correction for OMAP4 and 3630
314 * since freqsel field is no longer present
316 if (!soc_is_am33xx() && !cpu_is_omap44xx() && !cpu_is_omap3630()) {
317 v = __raw_readl(dd->control_reg);
318 v &= ~dd->freqsel_mask;
319 v |= freqsel << __ffs(dd->freqsel_mask);
320 __raw_writel(v, dd->control_reg);
323 /* Set DPLL multiplier, divider */
324 v = __raw_readl(dd->mult_div1_reg);
325 v &= ~(dd->mult_mask | dd->div1_mask);
326 v |= m << __ffs(dd->mult_mask);
327 v |= (n - 1) << __ffs(dd->div1_mask);
329 /* Configure dco and sd_div for dplls that have these fields */
331 _lookup_dco(clk, &dco, m, n);
332 v &= ~(dd->dco_mask);
333 v |= dco << __ffs(dd->dco_mask);
335 if (dd->sddiv_mask) {
336 _lookup_sddiv(clk, &sd_div, m, n);
337 v &= ~(dd->sddiv_mask);
338 v |= sd_div << __ffs(dd->sddiv_mask);
341 __raw_writel(v, dd->mult_div1_reg);
343 /* We let the clock framework set the other output dividers later */
345 /* REVISIT: Set ramp-up delay? */
347 _omap3_noncore_dpll_lock(clk);
352 /* Public functions */
355 * omap3_dpll_recalc - recalculate DPLL rate
356 * @clk: DPLL struct clk
358 * Recalculate and propagate the DPLL rate.
360 unsigned long omap3_dpll_recalc(struct clk *clk)
362 return omap2_get_dpll_rate(clk);
365 /* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
368 * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
369 * @clk: pointer to a DPLL struct clk
371 * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
372 * The choice of modes depends on the DPLL's programmed rate: if it is
373 * the same as the DPLL's parent clock, it will enter bypass;
374 * otherwise, it will enter lock. This code will wait for the DPLL to
375 * indicate readiness before returning, unless the DPLL takes too long
376 * to enter the target state. Intended to be used as the struct clk's
377 * enable function. If DPLL3 was passed in, or the DPLL does not
378 * support low-power stop, or if the DPLL took too long to enter
379 * bypass or lock, return -EINVAL; otherwise, return 0.
381 int omap3_noncore_dpll_enable(struct clk *clk)
384 struct dpll_data *dd;
391 parent = __clk_get_parent(clk);
393 if (__clk_get_rate(clk) == __clk_get_rate(dd->clk_bypass)) {
394 WARN_ON(parent != dd->clk_bypass);
395 r = _omap3_noncore_dpll_bypass(clk);
397 WARN_ON(parent != dd->clk_ref);
398 r = _omap3_noncore_dpll_lock(clk);
401 *FIXME: this is dubious - if clk->rate has changed, what about
405 clk->rate = (clk->recalc) ? clk->recalc(clk) :
406 omap2_get_dpll_rate(clk);
412 * omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop
413 * @clk: pointer to a DPLL struct clk
415 * Instructs a non-CORE DPLL to enter low-power stop. This function is
416 * intended for use in struct clkops. No return value.
418 void omap3_noncore_dpll_disable(struct clk *clk)
420 _omap3_noncore_dpll_stop(clk);
424 /* Non-CORE DPLL rate set code */
427 * omap3_noncore_dpll_set_rate - set non-core DPLL rate
428 * @clk: struct clk * of DPLL to set
429 * @rate: rounded target rate
431 * Set the DPLL CLKOUT to the target rate. If the DPLL can enter
432 * low-power bypass, and the target rate is the bypass source clock
433 * rate, then configure the DPLL for bypass. Otherwise, round the
434 * target rate if it hasn't been done already, then program and lock
435 * the DPLL. Returns -EINVAL upon error, or 0 upon success.
437 int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate)
439 struct clk *new_parent = NULL;
440 unsigned long hw_rate, bypass_rate;
442 struct dpll_data *dd;
452 hw_rate = (clk->recalc) ? clk->recalc(clk) : omap2_get_dpll_rate(clk);
457 * Ensure both the bypass and ref clocks are enabled prior to
458 * doing anything; we need the bypass clock running to reprogram
461 omap2_clk_enable(dd->clk_bypass);
462 omap2_clk_enable(dd->clk_ref);
464 bypass_rate = __clk_get_rate(dd->clk_bypass);
465 if (bypass_rate == rate &&
466 (clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
467 pr_debug("clock: %s: set rate: entering bypass.\n", clk->name);
469 ret = _omap3_noncore_dpll_bypass(clk);
471 new_parent = dd->clk_bypass;
473 if (dd->last_rounded_rate != rate)
474 rate = clk->round_rate(clk, rate);
476 if (dd->last_rounded_rate == 0)
479 /* No freqsel on OMAP4 and OMAP3630 */
480 if (!soc_is_am33xx() && !cpu_is_omap44xx() && !cpu_is_omap3630()) {
481 freqsel = _omap3_dpll_compute_freqsel(clk,
487 pr_debug("clock: %s: set rate: locking rate to %lu.\n",
488 __clk_get_name(clk), rate);
490 ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
491 dd->last_rounded_n, freqsel);
493 new_parent = dd->clk_ref;
497 * Switch the parent clock in the hierarchy, and make sure
498 * that the new parent's usecount is correct. Note: we
499 * enable the new parent before disabling the old to avoid
500 * any unnecessary hardware disable->enable transitions.
503 omap2_clk_enable(new_parent);
504 omap2_clk_disable(clk->parent);
506 clk_reparent(clk, new_parent);
509 omap2_clk_disable(dd->clk_ref);
510 omap2_clk_disable(dd->clk_bypass);
515 /* DPLL autoidle read/set code */
518 * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
519 * @clk: struct clk * of the DPLL to read
521 * Return the DPLL's autoidle bits, shifted down to bit 0. Returns
522 * -EINVAL if passed a null pointer or if the struct clk does not
523 * appear to refer to a DPLL.
525 u32 omap3_dpll_autoidle_read(struct clk *clk)
527 const struct dpll_data *dd;
530 if (!clk || !clk->dpll_data)
535 if (!dd->autoidle_reg)
538 v = __raw_readl(dd->autoidle_reg);
539 v &= dd->autoidle_mask;
540 v >>= __ffs(dd->autoidle_mask);
546 * omap3_dpll_allow_idle - enable DPLL autoidle bits
547 * @clk: struct clk * of the DPLL to operate on
549 * Enable DPLL automatic idle control. This automatic idle mode
550 * switching takes effect only when the DPLL is locked, at least on
551 * OMAP3430. The DPLL will enter low-power stop when its downstream
552 * clocks are gated. No return value.
554 void omap3_dpll_allow_idle(struct clk *clk)
556 const struct dpll_data *dd;
559 if (!clk || !clk->dpll_data)
564 if (!dd->autoidle_reg) {
565 pr_debug("clock: DPLL %s: autoidle not supported\n",
566 __clk_get_name(clk));
571 * REVISIT: CORE DPLL can optionally enter low-power bypass
572 * by writing 0x5 instead of 0x1. Add some mechanism to
573 * optionally enter this mode.
575 v = __raw_readl(dd->autoidle_reg);
576 v &= ~dd->autoidle_mask;
577 v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
578 __raw_writel(v, dd->autoidle_reg);
583 * omap3_dpll_deny_idle - prevent DPLL from automatically idling
584 * @clk: struct clk * of the DPLL to operate on
586 * Disable DPLL automatic idle control. No return value.
588 void omap3_dpll_deny_idle(struct clk *clk)
590 const struct dpll_data *dd;
593 if (!clk || !clk->dpll_data)
598 if (!dd->autoidle_reg) {
599 pr_debug("clock: DPLL %s: autoidle not supported\n",
600 __clk_get_name(clk));
604 v = __raw_readl(dd->autoidle_reg);
605 v &= ~dd->autoidle_mask;
606 v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
607 __raw_writel(v, dd->autoidle_reg);
611 /* Clock control for DPLL outputs */
614 * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
615 * @clk: DPLL output struct clk
617 * Using parent clock DPLL data, look up DPLL state. If locked, set our
618 * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
620 unsigned long omap3_clkoutx2_recalc(struct clk *clk)
622 const struct dpll_data *dd;
626 unsigned long parent_rate;
628 /* Walk up the parents of clk, looking for a DPLL */
629 pclk = __clk_get_parent(clk);
630 while (pclk && !pclk->dpll_data)
631 pclk = __clk_get_parent(pclk);
633 /* clk does not have a DPLL as a parent? */
636 dd = pclk->dpll_data;
638 WARN_ON(!dd->enable_mask);
640 parent_rate = __clk_get_rate(__clk_get_parent(clk));
641 v = __raw_readl(dd->control_reg) & dd->enable_mask;
642 v >>= __ffs(dd->enable_mask);
643 if ((v != OMAP3XXX_EN_DPLL_LOCKED) || (dd->flags & DPLL_J_TYPE))
646 rate = parent_rate * 2;
650 /* OMAP3/4 non-CORE DPLL clkops */
652 const struct clkops clkops_omap3_noncore_dpll_ops = {
653 .enable = omap3_noncore_dpll_enable,
654 .disable = omap3_noncore_dpll_disable,
655 .allow_idle = omap3_dpll_allow_idle,
656 .deny_idle = omap3_dpll_deny_idle,
659 const struct clkops clkops_omap3_core_dpll_ops = {
660 .allow_idle = omap3_dpll_allow_idle,
661 .deny_idle = omap3_dpll_deny_idle,