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 state <<= __ffs(dd->idlest_mask);
71 while (((__raw_readl(dd->idlest_reg) & dd->idlest_mask) != state) &&
72 i < MAX_DPLL_WAIT_TRIES) {
77 if (i == MAX_DPLL_WAIT_TRIES) {
78 printk(KERN_ERR "clock: %s failed transition to '%s'\n",
79 clk->name, (state) ? "locked" : "bypassed");
81 pr_debug("clock: %s transition to '%s' in %d loops\n",
82 clk->name, (state) ? "locked" : "bypassed", i);
90 /* From 3430 TRM ES2 4.7.6.2 */
91 static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
96 fint = clk->dpll_data->clk_ref->rate / n;
98 pr_debug("clock: fint is %lu\n", fint);
100 if (fint >= 750000 && fint <= 1000000)
102 else if (fint > 1000000 && fint <= 1250000)
104 else if (fint > 1250000 && fint <= 1500000)
106 else if (fint > 1500000 && fint <= 1750000)
108 else if (fint > 1750000 && fint <= 2100000)
110 else if (fint > 7500000 && fint <= 10000000)
112 else if (fint > 10000000 && fint <= 12500000)
114 else if (fint > 12500000 && fint <= 15000000)
116 else if (fint > 15000000 && fint <= 17500000)
118 else if (fint > 17500000 && fint <= 21000000)
121 pr_debug("clock: unknown freqsel setting for %d\n", n);
127 * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
128 * @clk: pointer to a DPLL struct clk
130 * Instructs a non-CORE DPLL to lock. Waits for the DPLL to report
131 * readiness before returning. Will save and restore the DPLL's
132 * autoidle state across the enable, per the CDP code. If the DPLL
133 * locked successfully, return 0; if the DPLL did not lock in the time
134 * allotted, or DPLL3 was passed in, return -EINVAL.
136 static int _omap3_noncore_dpll_lock(struct clk *clk)
138 const struct dpll_data *dd;
143 pr_debug("clock: locking DPLL %s\n", clk->name);
146 state <<= __ffs(dd->idlest_mask);
148 /* Check if already locked */
149 if ((__raw_readl(dd->idlest_reg) & dd->idlest_mask) == state)
152 ai = omap3_dpll_autoidle_read(clk);
155 omap3_dpll_deny_idle(clk);
157 _omap3_dpll_write_clken(clk, DPLL_LOCKED);
159 r = _omap3_wait_dpll_status(clk, 1);
162 omap3_dpll_allow_idle(clk);
169 * _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
170 * @clk: pointer to a DPLL struct clk
172 * Instructs a non-CORE DPLL to enter low-power bypass mode. In
173 * bypass mode, the DPLL's rate is set equal to its parent clock's
174 * rate. Waits for the DPLL to report readiness before returning.
175 * Will save and restore the DPLL's autoidle state across the enable,
176 * per the CDP code. If the DPLL entered bypass mode successfully,
177 * return 0; if the DPLL did not enter bypass in the time allotted, or
178 * DPLL3 was passed in, or the DPLL does not support low-power bypass,
181 static int _omap3_noncore_dpll_bypass(struct clk *clk)
186 if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
189 pr_debug("clock: configuring DPLL %s for low-power bypass\n",
192 ai = omap3_dpll_autoidle_read(clk);
194 _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);
196 r = _omap3_wait_dpll_status(clk, 0);
199 omap3_dpll_allow_idle(clk);
205 * _omap3_noncore_dpll_stop - instruct a DPLL to stop
206 * @clk: pointer to a DPLL struct clk
208 * Instructs a non-CORE DPLL to enter low-power stop. Will save and
209 * restore the DPLL's autoidle state across the stop, per the CDP
210 * code. If DPLL3 was passed in, or the DPLL does not support
211 * low-power stop, return -EINVAL; otherwise, return 0.
213 static int _omap3_noncore_dpll_stop(struct clk *clk)
217 if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
220 pr_debug("clock: stopping DPLL %s\n", clk->name);
222 ai = omap3_dpll_autoidle_read(clk);
224 _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);
227 omap3_dpll_allow_idle(clk);
233 * _lookup_dco - Lookup DCO used by j-type DPLL
234 * @clk: pointer to a DPLL struct clk
235 * @dco: digital control oscillator selector
236 * @m: DPLL multiplier to set
237 * @n: DPLL divider to set
239 * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
241 * XXX This code is not needed for 3430/AM35xx; can it be optimized
242 * out in non-multi-OMAP builds for those chips?
244 static void _lookup_dco(struct clk *clk, u8 *dco, u16 m, u8 n)
246 unsigned long fint, clkinp; /* watch out for overflow */
248 clkinp = clk->parent->rate;
249 fint = (clkinp / n) * m;
251 if (fint < 1000000000)
258 * _lookup_sddiv - Calculate sigma delta divider for j-type DPLL
259 * @clk: pointer to a DPLL struct clk
260 * @sd_div: target sigma-delta divider
261 * @m: DPLL multiplier to set
262 * @n: DPLL divider to set
264 * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
266 * XXX This code is not needed for 3430/AM35xx; can it be optimized
267 * out in non-multi-OMAP builds for those chips?
269 static void _lookup_sddiv(struct clk *clk, u8 *sd_div, u16 m, u8 n)
271 unsigned long clkinp, sd; /* watch out for overflow */
274 clkinp = clk->parent->rate;
277 * target sigma-delta to near 250MHz
278 * sd = ceil[(m/(n+1)) * (clkinp_MHz / 250)]
280 clkinp /= 100000; /* shift from MHz to 10*Hz for 38.4 and 19.2 */
281 mod1 = (clkinp * m) % (250 * n);
282 sd = (clkinp * m) / (250 * n);
292 * _omap3_noncore_dpll_program - set non-core DPLL M,N values directly
293 * @clk: struct clk * of DPLL to set
294 * @m: DPLL multiplier to set
295 * @n: DPLL divider to set
296 * @freqsel: FREQSEL value to set
298 * Program the DPLL with the supplied M, N values, and wait for the DPLL to
299 * lock.. Returns -EINVAL upon error, or 0 upon success.
301 static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
303 struct dpll_data *dd = clk->dpll_data;
307 /* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
308 _omap3_noncore_dpll_bypass(clk);
311 * Set jitter correction. No jitter correction for OMAP4 and 3630
312 * since freqsel field is no longer present
314 if (!soc_is_am33xx() && !cpu_is_omap44xx() && !cpu_is_omap3630()) {
315 v = __raw_readl(dd->control_reg);
316 v &= ~dd->freqsel_mask;
317 v |= freqsel << __ffs(dd->freqsel_mask);
318 __raw_writel(v, dd->control_reg);
321 /* Set DPLL multiplier, divider */
322 v = __raw_readl(dd->mult_div1_reg);
323 v &= ~(dd->mult_mask | dd->div1_mask);
324 v |= m << __ffs(dd->mult_mask);
325 v |= (n - 1) << __ffs(dd->div1_mask);
327 /* Configure dco and sd_div for dplls that have these fields */
329 _lookup_dco(clk, &dco, m, n);
330 v &= ~(dd->dco_mask);
331 v |= dco << __ffs(dd->dco_mask);
333 if (dd->sddiv_mask) {
334 _lookup_sddiv(clk, &sd_div, m, n);
335 v &= ~(dd->sddiv_mask);
336 v |= sd_div << __ffs(dd->sddiv_mask);
339 __raw_writel(v, dd->mult_div1_reg);
341 /* We let the clock framework set the other output dividers later */
343 /* REVISIT: Set ramp-up delay? */
345 _omap3_noncore_dpll_lock(clk);
350 /* Public functions */
353 * omap3_dpll_recalc - recalculate DPLL rate
354 * @clk: DPLL struct clk
356 * Recalculate and propagate the DPLL rate.
358 unsigned long omap3_dpll_recalc(struct clk *clk)
360 return omap2_get_dpll_rate(clk);
363 /* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
366 * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
367 * @clk: pointer to a DPLL struct clk
369 * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
370 * The choice of modes depends on the DPLL's programmed rate: if it is
371 * the same as the DPLL's parent clock, it will enter bypass;
372 * otherwise, it will enter lock. This code will wait for the DPLL to
373 * indicate readiness before returning, unless the DPLL takes too long
374 * to enter the target state. Intended to be used as the struct clk's
375 * enable function. If DPLL3 was passed in, or the DPLL does not
376 * support low-power stop, or if the DPLL took too long to enter
377 * bypass or lock, return -EINVAL; otherwise, return 0.
379 int omap3_noncore_dpll_enable(struct clk *clk)
382 struct dpll_data *dd;
388 if (clk->rate == dd->clk_bypass->rate) {
389 WARN_ON(clk->parent != dd->clk_bypass);
390 r = _omap3_noncore_dpll_bypass(clk);
392 WARN_ON(clk->parent != dd->clk_ref);
393 r = _omap3_noncore_dpll_lock(clk);
396 *FIXME: this is dubious - if clk->rate has changed, what about
400 clk->rate = (clk->recalc) ? clk->recalc(clk) :
401 omap2_get_dpll_rate(clk);
407 * omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop
408 * @clk: pointer to a DPLL struct clk
410 * Instructs a non-CORE DPLL to enter low-power stop. This function is
411 * intended for use in struct clkops. No return value.
413 void omap3_noncore_dpll_disable(struct clk *clk)
415 _omap3_noncore_dpll_stop(clk);
419 /* Non-CORE DPLL rate set code */
422 * omap3_noncore_dpll_set_rate - set non-core DPLL rate
423 * @clk: struct clk * of DPLL to set
424 * @rate: rounded target rate
426 * Set the DPLL CLKOUT to the target rate. If the DPLL can enter
427 * low-power bypass, and the target rate is the bypass source clock
428 * rate, then configure the DPLL for bypass. Otherwise, round the
429 * target rate if it hasn't been done already, then program and lock
430 * the DPLL. Returns -EINVAL upon error, or 0 upon success.
432 int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate)
434 struct clk *new_parent = NULL;
435 unsigned long hw_rate;
437 struct dpll_data *dd;
447 hw_rate = (clk->recalc) ? clk->recalc(clk) : omap2_get_dpll_rate(clk);
452 * Ensure both the bypass and ref clocks are enabled prior to
453 * doing anything; we need the bypass clock running to reprogram
456 omap2_clk_enable(dd->clk_bypass);
457 omap2_clk_enable(dd->clk_ref);
459 if (dd->clk_bypass->rate == rate &&
460 (clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
461 pr_debug("clock: %s: set rate: entering bypass.\n", clk->name);
463 ret = _omap3_noncore_dpll_bypass(clk);
465 new_parent = dd->clk_bypass;
467 if (dd->last_rounded_rate != rate)
468 rate = clk->round_rate(clk, rate);
470 if (dd->last_rounded_rate == 0)
473 /* No freqsel on OMAP4 and OMAP3630 */
474 if (!soc_is_am33xx() && !cpu_is_omap44xx() && !cpu_is_omap3630()) {
475 freqsel = _omap3_dpll_compute_freqsel(clk,
481 pr_debug("clock: %s: set rate: locking rate to %lu.\n",
484 ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
485 dd->last_rounded_n, freqsel);
487 new_parent = dd->clk_ref;
491 * Switch the parent clock in the hierarchy, and make sure
492 * that the new parent's usecount is correct. Note: we
493 * enable the new parent before disabling the old to avoid
494 * any unnecessary hardware disable->enable transitions.
497 omap2_clk_enable(new_parent);
498 omap2_clk_disable(clk->parent);
500 clk_reparent(clk, new_parent);
503 omap2_clk_disable(dd->clk_ref);
504 omap2_clk_disable(dd->clk_bypass);
509 /* DPLL autoidle read/set code */
512 * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
513 * @clk: struct clk * of the DPLL to read
515 * Return the DPLL's autoidle bits, shifted down to bit 0. Returns
516 * -EINVAL if passed a null pointer or if the struct clk does not
517 * appear to refer to a DPLL.
519 u32 omap3_dpll_autoidle_read(struct clk *clk)
521 const struct dpll_data *dd;
524 if (!clk || !clk->dpll_data)
529 if (!dd->autoidle_reg)
532 v = __raw_readl(dd->autoidle_reg);
533 v &= dd->autoidle_mask;
534 v >>= __ffs(dd->autoidle_mask);
540 * omap3_dpll_allow_idle - enable DPLL autoidle bits
541 * @clk: struct clk * of the DPLL to operate on
543 * Enable DPLL automatic idle control. This automatic idle mode
544 * switching takes effect only when the DPLL is locked, at least on
545 * OMAP3430. The DPLL will enter low-power stop when its downstream
546 * clocks are gated. No return value.
548 void omap3_dpll_allow_idle(struct clk *clk)
550 const struct dpll_data *dd;
553 if (!clk || !clk->dpll_data)
558 if (!dd->autoidle_reg) {
559 pr_debug("clock: DPLL %s: autoidle not supported\n",
565 * REVISIT: CORE DPLL can optionally enter low-power bypass
566 * by writing 0x5 instead of 0x1. Add some mechanism to
567 * optionally enter this mode.
569 v = __raw_readl(dd->autoidle_reg);
570 v &= ~dd->autoidle_mask;
571 v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
572 __raw_writel(v, dd->autoidle_reg);
577 * omap3_dpll_deny_idle - prevent DPLL from automatically idling
578 * @clk: struct clk * of the DPLL to operate on
580 * Disable DPLL automatic idle control. No return value.
582 void omap3_dpll_deny_idle(struct clk *clk)
584 const struct dpll_data *dd;
587 if (!clk || !clk->dpll_data)
592 if (!dd->autoidle_reg) {
593 pr_debug("clock: DPLL %s: autoidle not supported\n",
598 v = __raw_readl(dd->autoidle_reg);
599 v &= ~dd->autoidle_mask;
600 v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
601 __raw_writel(v, dd->autoidle_reg);
605 /* Clock control for DPLL outputs */
608 * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
609 * @clk: DPLL output struct clk
611 * Using parent clock DPLL data, look up DPLL state. If locked, set our
612 * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
614 unsigned long omap3_clkoutx2_recalc(struct clk *clk)
616 const struct dpll_data *dd;
621 /* Walk up the parents of clk, looking for a DPLL */
623 while (pclk && !pclk->dpll_data)
626 /* clk does not have a DPLL as a parent? error in the clock data */
632 dd = pclk->dpll_data;
634 WARN_ON(!dd->enable_mask);
636 v = __raw_readl(dd->control_reg) & dd->enable_mask;
637 v >>= __ffs(dd->enable_mask);
638 if ((v != OMAP3XXX_EN_DPLL_LOCKED) || (dd->flags & DPLL_J_TYPE))
639 rate = clk->parent->rate;
641 rate = clk->parent->rate * 2;
645 /* OMAP3/4 non-CORE DPLL clkops */
647 const struct clkops clkops_omap3_noncore_dpll_ops = {
648 .enable = omap3_noncore_dpll_enable,
649 .disable = omap3_noncore_dpll_disable,
650 .allow_idle = omap3_dpll_allow_idle,
651 .deny_idle = omap3_dpll_deny_idle,
654 const struct clkops clkops_omap3_core_dpll_ops = {
655 .allow_idle = omap3_dpll_allow_idle,
656 .deny_idle = omap3_dpll_deny_idle,