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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP3/4 - specific DPLL control functions
4  *
5  * Copyright (C) 2009-2010 Texas Instruments, Inc.
6  * Copyright (C) 2009-2010 Nokia Corporation
7  *
8  * Written by Paul Walmsley
9  * Testing and integration fixes by Jouni Högander
10  *
11  * 36xx support added by Vishwanath BS, Richard Woodruff, and Nishanth
12  * Menon
13  *
14  * Parts of this code are based on code written by
15  * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
16  */
17 
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>
24 #include <linux/io.h>
25 #include <linux/bitops.h>
26 #include <linux/clkdev.h>
27 #include <linux/clk/ti.h>
28 
29 #include "clock.h"
30 
31 /* CM_AUTOIDLE_PLL*.AUTO_* bit values */
32 #define DPLL_AUTOIDLE_DISABLE			0x0
33 #define DPLL_AUTOIDLE_LOW_POWER_STOP		0x1
34 
35 #define MAX_DPLL_WAIT_TRIES		1000000
36 
37 #define OMAP3XXX_EN_DPLL_LOCKED		0x7
38 
39 /* Forward declarations */
40 static u32 omap3_dpll_autoidle_read(struct clk_hw_omap *clk);
41 static void omap3_dpll_deny_idle(struct clk_hw_omap *clk);
42 static void omap3_dpll_allow_idle(struct clk_hw_omap *clk);
43 
44 /* Private functions */
45 
46 /* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
_omap3_dpll_write_clken(struct clk_hw_omap * clk,u8 clken_bits)47 static void _omap3_dpll_write_clken(struct clk_hw_omap *clk, u8 clken_bits)
48 {
49 	const struct dpll_data *dd;
50 	u32 v;
51 
52 	dd = clk->dpll_data;
53 
54 	v = ti_clk_ll_ops->clk_readl(&dd->control_reg);
55 	v &= ~dd->enable_mask;
56 	v |= clken_bits << __ffs(dd->enable_mask);
57 	ti_clk_ll_ops->clk_writel(v, &dd->control_reg);
58 }
59 
60 /* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
_omap3_wait_dpll_status(struct clk_hw_omap * clk,u8 state)61 static int _omap3_wait_dpll_status(struct clk_hw_omap *clk, u8 state)
62 {
63 	const struct dpll_data *dd;
64 	int i = 0;
65 	int ret = -EINVAL;
66 	const char *clk_name;
67 
68 	dd = clk->dpll_data;
69 	clk_name = clk_hw_get_name(&clk->hw);
70 
71 	state <<= __ffs(dd->idlest_mask);
72 
73 	while (((ti_clk_ll_ops->clk_readl(&dd->idlest_reg) & dd->idlest_mask)
74 		!= state) && i < MAX_DPLL_WAIT_TRIES) {
75 		i++;
76 		udelay(1);
77 	}
78 
79 	if (i == MAX_DPLL_WAIT_TRIES) {
80 		pr_err("clock: %s failed transition to '%s'\n",
81 		       clk_name, (state) ? "locked" : "bypassed");
82 	} else {
83 		pr_debug("clock: %s transition to '%s' in %d loops\n",
84 			 clk_name, (state) ? "locked" : "bypassed", i);
85 
86 		ret = 0;
87 	}
88 
89 	return ret;
90 }
91 
92 /* From 3430 TRM ES2 4.7.6.2 */
_omap3_dpll_compute_freqsel(struct clk_hw_omap * clk,u8 n)93 static u16 _omap3_dpll_compute_freqsel(struct clk_hw_omap *clk, u8 n)
94 {
95 	unsigned long fint;
96 	u16 f = 0;
97 
98 	fint = clk_hw_get_rate(clk->dpll_data->clk_ref) / n;
99 
100 	pr_debug("clock: fint is %lu\n", fint);
101 
102 	if (fint >= 750000 && fint <= 1000000)
103 		f = 0x3;
104 	else if (fint > 1000000 && fint <= 1250000)
105 		f = 0x4;
106 	else if (fint > 1250000 && fint <= 1500000)
107 		f = 0x5;
108 	else if (fint > 1500000 && fint <= 1750000)
109 		f = 0x6;
110 	else if (fint > 1750000 && fint <= 2100000)
111 		f = 0x7;
112 	else if (fint > 7500000 && fint <= 10000000)
113 		f = 0xB;
114 	else if (fint > 10000000 && fint <= 12500000)
115 		f = 0xC;
116 	else if (fint > 12500000 && fint <= 15000000)
117 		f = 0xD;
118 	else if (fint > 15000000 && fint <= 17500000)
119 		f = 0xE;
120 	else if (fint > 17500000 && fint <= 21000000)
121 		f = 0xF;
122 	else
123 		pr_debug("clock: unknown freqsel setting for %d\n", n);
124 
125 	return f;
126 }
127 
128 /*
129  * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
130  * @clk: pointer to a DPLL struct clk
131  *
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.
137  */
_omap3_noncore_dpll_lock(struct clk_hw_omap * clk)138 static int _omap3_noncore_dpll_lock(struct clk_hw_omap *clk)
139 {
140 	const struct dpll_data *dd;
141 	u8 ai;
142 	u8 state = 1;
143 	int r = 0;
144 
145 	pr_debug("clock: locking DPLL %s\n", clk_hw_get_name(&clk->hw));
146 
147 	dd = clk->dpll_data;
148 	state <<= __ffs(dd->idlest_mask);
149 
150 	/* Check if already locked */
151 	if ((ti_clk_ll_ops->clk_readl(&dd->idlest_reg) & dd->idlest_mask) ==
152 	    state)
153 		goto done;
154 
155 	ai = omap3_dpll_autoidle_read(clk);
156 
157 	if (ai)
158 		omap3_dpll_deny_idle(clk);
159 
160 	_omap3_dpll_write_clken(clk, DPLL_LOCKED);
161 
162 	r = _omap3_wait_dpll_status(clk, 1);
163 
164 	if (ai)
165 		omap3_dpll_allow_idle(clk);
166 
167 done:
168 	return r;
169 }
170 
171 /*
172  * _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
173  * @clk: pointer to a DPLL struct clk
174  *
175  * Instructs a non-CORE DPLL to enter low-power bypass mode.  In
176  * bypass mode, the DPLL's rate is set equal to its parent clock's
177  * rate.  Waits for the DPLL to report readiness before returning.
178  * Will save and restore the DPLL's autoidle state across the enable,
179  * per the CDP code.  If the DPLL entered bypass mode successfully,
180  * return 0; if the DPLL did not enter bypass in the time allotted, or
181  * DPLL3 was passed in, or the DPLL does not support low-power bypass,
182  * return -EINVAL.
183  */
_omap3_noncore_dpll_bypass(struct clk_hw_omap * clk)184 static int _omap3_noncore_dpll_bypass(struct clk_hw_omap *clk)
185 {
186 	int r;
187 	u8 ai;
188 
189 	if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
190 		return -EINVAL;
191 
192 	pr_debug("clock: configuring DPLL %s for low-power bypass\n",
193 		 clk_hw_get_name(&clk->hw));
194 
195 	ai = omap3_dpll_autoidle_read(clk);
196 
197 	_omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);
198 
199 	r = _omap3_wait_dpll_status(clk, 0);
200 
201 	if (ai)
202 		omap3_dpll_allow_idle(clk);
203 
204 	return r;
205 }
206 
207 /*
208  * _omap3_noncore_dpll_stop - instruct a DPLL to stop
209  * @clk: pointer to a DPLL struct clk
210  *
211  * Instructs a non-CORE DPLL to enter low-power stop. Will save and
212  * restore the DPLL's autoidle state across the stop, per the CDP
213  * code.  If DPLL3 was passed in, or the DPLL does not support
214  * low-power stop, return -EINVAL; otherwise, return 0.
215  */
_omap3_noncore_dpll_stop(struct clk_hw_omap * clk)216 static int _omap3_noncore_dpll_stop(struct clk_hw_omap *clk)
217 {
218 	u8 ai;
219 
220 	if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
221 		return -EINVAL;
222 
223 	pr_debug("clock: stopping DPLL %s\n", clk_hw_get_name(&clk->hw));
224 
225 	ai = omap3_dpll_autoidle_read(clk);
226 
227 	_omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);
228 
229 	if (ai)
230 		omap3_dpll_allow_idle(clk);
231 
232 	return 0;
233 }
234 
235 /**
236  * _lookup_dco - Lookup DCO used by j-type DPLL
237  * @clk: pointer to a DPLL struct clk
238  * @dco: digital control oscillator selector
239  * @m: DPLL multiplier to set
240  * @n: DPLL divider to set
241  *
242  * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
243  *
244  * XXX This code is not needed for 3430/AM35xx; can it be optimized
245  * out in non-multi-OMAP builds for those chips?
246  */
_lookup_dco(struct clk_hw_omap * clk,u8 * dco,u16 m,u8 n)247 static void _lookup_dco(struct clk_hw_omap *clk, u8 *dco, u16 m, u8 n)
248 {
249 	unsigned long fint, clkinp; /* watch out for overflow */
250 
251 	clkinp = clk_hw_get_rate(clk_hw_get_parent(&clk->hw));
252 	fint = (clkinp / n) * m;
253 
254 	if (fint < 1000000000)
255 		*dco = 2;
256 	else
257 		*dco = 4;
258 }
259 
260 /**
261  * _lookup_sddiv - Calculate sigma delta divider for j-type DPLL
262  * @clk: pointer to a DPLL struct clk
263  * @sd_div: target sigma-delta divider
264  * @m: DPLL multiplier to set
265  * @n: DPLL divider to set
266  *
267  * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
268  *
269  * XXX This code is not needed for 3430/AM35xx; can it be optimized
270  * out in non-multi-OMAP builds for those chips?
271  */
_lookup_sddiv(struct clk_hw_omap * clk,u8 * sd_div,u16 m,u8 n)272 static void _lookup_sddiv(struct clk_hw_omap *clk, u8 *sd_div, u16 m, u8 n)
273 {
274 	unsigned long clkinp, sd; /* watch out for overflow */
275 	int mod1, mod2;
276 
277 	clkinp = clk_hw_get_rate(clk_hw_get_parent(&clk->hw));
278 
279 	/*
280 	 * target sigma-delta to near 250MHz
281 	 * sd = ceil[(m/(n+1)) * (clkinp_MHz / 250)]
282 	 */
283 	clkinp /= 100000; /* shift from MHz to 10*Hz for 38.4 and 19.2 */
284 	mod1 = (clkinp * m) % (250 * n);
285 	sd = (clkinp * m) / (250 * n);
286 	mod2 = sd % 10;
287 	sd /= 10;
288 
289 	if (mod1 || mod2)
290 		sd++;
291 	*sd_div = sd;
292 }
293 
294 /*
295  * _omap3_noncore_dpll_program - set non-core DPLL M,N values directly
296  * @clk:	struct clk * of DPLL to set
297  * @freqsel:	FREQSEL value to set
298  *
299  * Program the DPLL with the last M, N values calculated, and wait for
300  * the DPLL to lock. Returns -EINVAL upon error, or 0 upon success.
301  */
omap3_noncore_dpll_program(struct clk_hw_omap * clk,u16 freqsel)302 static int omap3_noncore_dpll_program(struct clk_hw_omap *clk, u16 freqsel)
303 {
304 	struct dpll_data *dd = clk->dpll_data;
305 	u8 dco, sd_div, ai = 0;
306 	u32 v;
307 	bool errata_i810;
308 
309 	/* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
310 	_omap3_noncore_dpll_bypass(clk);
311 
312 	/*
313 	 * Set jitter correction. Jitter correction applicable for OMAP343X
314 	 * only since freqsel field is no longer present on other devices.
315 	 */
316 	if (ti_clk_get_features()->flags & TI_CLK_DPLL_HAS_FREQSEL) {
317 		v = ti_clk_ll_ops->clk_readl(&dd->control_reg);
318 		v &= ~dd->freqsel_mask;
319 		v |= freqsel << __ffs(dd->freqsel_mask);
320 		ti_clk_ll_ops->clk_writel(v, &dd->control_reg);
321 	}
322 
323 	/* Set DPLL multiplier, divider */
324 	v = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
325 
326 	/* Handle Duty Cycle Correction */
327 	if (dd->dcc_mask) {
328 		if (dd->last_rounded_rate >= dd->dcc_rate)
329 			v |= dd->dcc_mask; /* Enable DCC */
330 		else
331 			v &= ~dd->dcc_mask; /* Disable DCC */
332 	}
333 
334 	v &= ~(dd->mult_mask | dd->div1_mask);
335 	v |= dd->last_rounded_m << __ffs(dd->mult_mask);
336 	v |= (dd->last_rounded_n - 1) << __ffs(dd->div1_mask);
337 
338 	/* Configure dco and sd_div for dplls that have these fields */
339 	if (dd->dco_mask) {
340 		_lookup_dco(clk, &dco, dd->last_rounded_m, dd->last_rounded_n);
341 		v &= ~(dd->dco_mask);
342 		v |= dco << __ffs(dd->dco_mask);
343 	}
344 	if (dd->sddiv_mask) {
345 		_lookup_sddiv(clk, &sd_div, dd->last_rounded_m,
346 			      dd->last_rounded_n);
347 		v &= ~(dd->sddiv_mask);
348 		v |= sd_div << __ffs(dd->sddiv_mask);
349 	}
350 
351 	/*
352 	 * Errata i810 - DPLL controller can get stuck while transitioning
353 	 * to a power saving state. Software must ensure the DPLL can not
354 	 * transition to a low power state while changing M/N values.
355 	 * Easiest way to accomplish this is to prevent DPLL autoidle
356 	 * before doing the M/N re-program.
357 	 */
358 	errata_i810 = ti_clk_get_features()->flags & TI_CLK_ERRATA_I810;
359 
360 	if (errata_i810) {
361 		ai = omap3_dpll_autoidle_read(clk);
362 		if (ai) {
363 			omap3_dpll_deny_idle(clk);
364 
365 			/* OCP barrier */
366 			omap3_dpll_autoidle_read(clk);
367 		}
368 	}
369 
370 	ti_clk_ll_ops->clk_writel(v, &dd->mult_div1_reg);
371 
372 	/* Set 4X multiplier and low-power mode */
373 	if (dd->m4xen_mask || dd->lpmode_mask) {
374 		v = ti_clk_ll_ops->clk_readl(&dd->control_reg);
375 
376 		if (dd->m4xen_mask) {
377 			if (dd->last_rounded_m4xen)
378 				v |= dd->m4xen_mask;
379 			else
380 				v &= ~dd->m4xen_mask;
381 		}
382 
383 		if (dd->lpmode_mask) {
384 			if (dd->last_rounded_lpmode)
385 				v |= dd->lpmode_mask;
386 			else
387 				v &= ~dd->lpmode_mask;
388 		}
389 
390 		ti_clk_ll_ops->clk_writel(v, &dd->control_reg);
391 	}
392 
393 	/* We let the clock framework set the other output dividers later */
394 
395 	/* REVISIT: Set ramp-up delay? */
396 
397 	_omap3_noncore_dpll_lock(clk);
398 
399 	if (errata_i810 && ai)
400 		omap3_dpll_allow_idle(clk);
401 
402 	return 0;
403 }
404 
405 /* Public functions */
406 
407 /**
408  * omap3_dpll_recalc - recalculate DPLL rate
409  * @clk: DPLL struct clk
410  *
411  * Recalculate and propagate the DPLL rate.
412  */
omap3_dpll_recalc(struct clk_hw * hw,unsigned long parent_rate)413 unsigned long omap3_dpll_recalc(struct clk_hw *hw, unsigned long parent_rate)
414 {
415 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
416 
417 	return omap2_get_dpll_rate(clk);
418 }
419 
420 /* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
421 
422 /**
423  * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
424  * @clk: pointer to a DPLL struct clk
425  *
426  * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
427  * The choice of modes depends on the DPLL's programmed rate: if it is
428  * the same as the DPLL's parent clock, it will enter bypass;
429  * otherwise, it will enter lock.  This code will wait for the DPLL to
430  * indicate readiness before returning, unless the DPLL takes too long
431  * to enter the target state.  Intended to be used as the struct clk's
432  * enable function.  If DPLL3 was passed in, or the DPLL does not
433  * support low-power stop, or if the DPLL took too long to enter
434  * bypass or lock, return -EINVAL; otherwise, return 0.
435  */
omap3_noncore_dpll_enable(struct clk_hw * hw)436 int omap3_noncore_dpll_enable(struct clk_hw *hw)
437 {
438 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
439 	int r;
440 	struct dpll_data *dd;
441 	struct clk_hw *parent;
442 
443 	dd = clk->dpll_data;
444 	if (!dd)
445 		return -EINVAL;
446 
447 	if (clk->clkdm) {
448 		r = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
449 		if (r) {
450 			WARN(1,
451 			     "%s: could not enable %s's clockdomain %s: %d\n",
452 			     __func__, clk_hw_get_name(hw),
453 			     clk->clkdm_name, r);
454 			return r;
455 		}
456 	}
457 
458 	parent = clk_hw_get_parent(hw);
459 
460 	if (clk_hw_get_rate(hw) == clk_hw_get_rate(dd->clk_bypass)) {
461 		WARN_ON(parent != dd->clk_bypass);
462 		r = _omap3_noncore_dpll_bypass(clk);
463 	} else {
464 		WARN_ON(parent != dd->clk_ref);
465 		r = _omap3_noncore_dpll_lock(clk);
466 	}
467 
468 	return r;
469 }
470 
471 /**
472  * omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop
473  * @clk: pointer to a DPLL struct clk
474  *
475  * Instructs a non-CORE DPLL to enter low-power stop.  This function is
476  * intended for use in struct clkops.  No return value.
477  */
omap3_noncore_dpll_disable(struct clk_hw * hw)478 void omap3_noncore_dpll_disable(struct clk_hw *hw)
479 {
480 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
481 
482 	_omap3_noncore_dpll_stop(clk);
483 	if (clk->clkdm)
484 		ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
485 }
486 
487 /* Non-CORE DPLL rate set code */
488 
489 /**
490  * omap3_noncore_dpll_determine_rate - determine rate for a DPLL
491  * @hw: pointer to the clock to determine rate for
492  * @req: target rate request
493  *
494  * Determines which DPLL mode to use for reaching a desired target rate.
495  * Checks whether the DPLL shall be in bypass or locked mode, and if
496  * locked, calculates the M,N values for the DPLL via round-rate.
497  * Returns a 0 on success, negative error value in failure.
498  */
omap3_noncore_dpll_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)499 int omap3_noncore_dpll_determine_rate(struct clk_hw *hw,
500 				      struct clk_rate_request *req)
501 {
502 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
503 	struct dpll_data *dd;
504 
505 	if (!req->rate)
506 		return -EINVAL;
507 
508 	dd = clk->dpll_data;
509 	if (!dd)
510 		return -EINVAL;
511 
512 	if (clk_hw_get_rate(dd->clk_bypass) == req->rate &&
513 	    (dd->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
514 		req->best_parent_hw = dd->clk_bypass;
515 	} else {
516 		req->rate = omap2_dpll_round_rate(hw, req->rate,
517 					  &req->best_parent_rate);
518 		req->best_parent_hw = dd->clk_ref;
519 	}
520 
521 	req->best_parent_rate = req->rate;
522 
523 	return 0;
524 }
525 
526 /**
527  * omap3_noncore_dpll_set_parent - set parent for a DPLL clock
528  * @hw: pointer to the clock to set parent for
529  * @index: parent index to select
530  *
531  * Sets parent for a DPLL clock. This sets the DPLL into bypass or
532  * locked mode. Returns 0 with success, negative error value otherwise.
533  */
omap3_noncore_dpll_set_parent(struct clk_hw * hw,u8 index)534 int omap3_noncore_dpll_set_parent(struct clk_hw *hw, u8 index)
535 {
536 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
537 	int ret;
538 
539 	if (!hw)
540 		return -EINVAL;
541 
542 	if (index)
543 		ret = _omap3_noncore_dpll_bypass(clk);
544 	else
545 		ret = _omap3_noncore_dpll_lock(clk);
546 
547 	return ret;
548 }
549 
550 /**
551  * omap3_noncore_dpll_set_rate - set rate for a DPLL clock
552  * @hw: pointer to the clock to set parent for
553  * @rate: target rate for the clock
554  * @parent_rate: rate of the parent clock
555  *
556  * Sets rate for a DPLL clock. First checks if the clock parent is
557  * reference clock (in bypass mode, the rate of the clock can't be
558  * changed) and proceeds with the rate change operation. Returns 0
559  * with success, negative error value otherwise.
560  */
omap3_noncore_dpll_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)561 int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate,
562 				unsigned long parent_rate)
563 {
564 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
565 	struct dpll_data *dd;
566 	u16 freqsel = 0;
567 	int ret;
568 
569 	if (!hw || !rate)
570 		return -EINVAL;
571 
572 	dd = clk->dpll_data;
573 	if (!dd)
574 		return -EINVAL;
575 
576 	if (clk_hw_get_parent(hw) != dd->clk_ref)
577 		return -EINVAL;
578 
579 	if (dd->last_rounded_rate == 0)
580 		return -EINVAL;
581 
582 	/* Freqsel is available only on OMAP343X devices */
583 	if (ti_clk_get_features()->flags & TI_CLK_DPLL_HAS_FREQSEL) {
584 		freqsel = _omap3_dpll_compute_freqsel(clk, dd->last_rounded_n);
585 		WARN_ON(!freqsel);
586 	}
587 
588 	pr_debug("%s: %s: set rate: locking rate to %lu.\n", __func__,
589 		 clk_hw_get_name(hw), rate);
590 
591 	ret = omap3_noncore_dpll_program(clk, freqsel);
592 
593 	return ret;
594 }
595 
596 /**
597  * omap3_noncore_dpll_set_rate_and_parent - set rate and parent for a DPLL clock
598  * @hw: pointer to the clock to set rate and parent for
599  * @rate: target rate for the DPLL
600  * @parent_rate: clock rate of the DPLL parent
601  * @index: new parent index for the DPLL, 0 - reference, 1 - bypass
602  *
603  * Sets rate and parent for a DPLL clock. If new parent is the bypass
604  * clock, only selects the parent. Otherwise proceeds with a rate
605  * change, as this will effectively also change the parent as the
606  * DPLL is put into locked mode. Returns 0 with success, negative error
607  * value otherwise.
608  */
omap3_noncore_dpll_set_rate_and_parent(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate,u8 index)609 int omap3_noncore_dpll_set_rate_and_parent(struct clk_hw *hw,
610 					   unsigned long rate,
611 					   unsigned long parent_rate,
612 					   u8 index)
613 {
614 	int ret;
615 
616 	if (!hw || !rate)
617 		return -EINVAL;
618 
619 	/*
620 	 * clk-ref at index[0], in which case we only need to set rate,
621 	 * the parent will be changed automatically with the lock sequence.
622 	 * With clk-bypass case we only need to change parent.
623 	 */
624 	if (index)
625 		ret = omap3_noncore_dpll_set_parent(hw, index);
626 	else
627 		ret = omap3_noncore_dpll_set_rate(hw, rate, parent_rate);
628 
629 	return ret;
630 }
631 
632 /* DPLL autoidle read/set code */
633 
634 /**
635  * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
636  * @clk: struct clk * of the DPLL to read
637  *
638  * Return the DPLL's autoidle bits, shifted down to bit 0.  Returns
639  * -EINVAL if passed a null pointer or if the struct clk does not
640  * appear to refer to a DPLL.
641  */
omap3_dpll_autoidle_read(struct clk_hw_omap * clk)642 static u32 omap3_dpll_autoidle_read(struct clk_hw_omap *clk)
643 {
644 	const struct dpll_data *dd;
645 	u32 v;
646 
647 	if (!clk || !clk->dpll_data)
648 		return -EINVAL;
649 
650 	dd = clk->dpll_data;
651 
652 	if (!dd->autoidle_mask)
653 		return -EINVAL;
654 
655 	v = ti_clk_ll_ops->clk_readl(&dd->autoidle_reg);
656 	v &= dd->autoidle_mask;
657 	v >>= __ffs(dd->autoidle_mask);
658 
659 	return v;
660 }
661 
662 /**
663  * omap3_dpll_allow_idle - enable DPLL autoidle bits
664  * @clk: struct clk * of the DPLL to operate on
665  *
666  * Enable DPLL automatic idle control.  This automatic idle mode
667  * switching takes effect only when the DPLL is locked, at least on
668  * OMAP3430.  The DPLL will enter low-power stop when its downstream
669  * clocks are gated.  No return value.
670  */
omap3_dpll_allow_idle(struct clk_hw_omap * clk)671 static void omap3_dpll_allow_idle(struct clk_hw_omap *clk)
672 {
673 	const struct dpll_data *dd;
674 	u32 v;
675 
676 	if (!clk || !clk->dpll_data)
677 		return;
678 
679 	dd = clk->dpll_data;
680 
681 	if (!dd->autoidle_mask)
682 		return;
683 
684 	/*
685 	 * REVISIT: CORE DPLL can optionally enter low-power bypass
686 	 * by writing 0x5 instead of 0x1.  Add some mechanism to
687 	 * optionally enter this mode.
688 	 */
689 	v = ti_clk_ll_ops->clk_readl(&dd->autoidle_reg);
690 	v &= ~dd->autoidle_mask;
691 	v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
692 	ti_clk_ll_ops->clk_writel(v, &dd->autoidle_reg);
693 }
694 
695 /**
696  * omap3_dpll_deny_idle - prevent DPLL from automatically idling
697  * @clk: struct clk * of the DPLL to operate on
698  *
699  * Disable DPLL automatic idle control.  No return value.
700  */
omap3_dpll_deny_idle(struct clk_hw_omap * clk)701 static void omap3_dpll_deny_idle(struct clk_hw_omap *clk)
702 {
703 	const struct dpll_data *dd;
704 	u32 v;
705 
706 	if (!clk || !clk->dpll_data)
707 		return;
708 
709 	dd = clk->dpll_data;
710 
711 	if (!dd->autoidle_mask)
712 		return;
713 
714 	v = ti_clk_ll_ops->clk_readl(&dd->autoidle_reg);
715 	v &= ~dd->autoidle_mask;
716 	v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
717 	ti_clk_ll_ops->clk_writel(v, &dd->autoidle_reg);
718 }
719 
720 /* Clock control for DPLL outputs */
721 
722 /* Find the parent DPLL for the given clkoutx2 clock */
omap3_find_clkoutx2_dpll(struct clk_hw * hw)723 static struct clk_hw_omap *omap3_find_clkoutx2_dpll(struct clk_hw *hw)
724 {
725 	struct clk_hw_omap *pclk = NULL;
726 
727 	/* Walk up the parents of clk, looking for a DPLL */
728 	do {
729 		do {
730 			hw = clk_hw_get_parent(hw);
731 		} while (hw && (!omap2_clk_is_hw_omap(hw)));
732 		if (!hw)
733 			break;
734 		pclk = to_clk_hw_omap(hw);
735 	} while (pclk && !pclk->dpll_data);
736 
737 	/* clk does not have a DPLL as a parent?  error in the clock data */
738 	if (!pclk) {
739 		WARN_ON(1);
740 		return NULL;
741 	}
742 
743 	return pclk;
744 }
745 
746 /**
747  * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
748  * @clk: DPLL output struct clk
749  *
750  * Using parent clock DPLL data, look up DPLL state.  If locked, set our
751  * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
752  */
omap3_clkoutx2_recalc(struct clk_hw * hw,unsigned long parent_rate)753 unsigned long omap3_clkoutx2_recalc(struct clk_hw *hw,
754 				    unsigned long parent_rate)
755 {
756 	const struct dpll_data *dd;
757 	unsigned long rate;
758 	u32 v;
759 	struct clk_hw_omap *pclk = NULL;
760 
761 	if (!parent_rate)
762 		return 0;
763 
764 	pclk = omap3_find_clkoutx2_dpll(hw);
765 
766 	if (!pclk)
767 		return 0;
768 
769 	dd = pclk->dpll_data;
770 
771 	WARN_ON(!dd->enable_mask);
772 
773 	v = ti_clk_ll_ops->clk_readl(&dd->control_reg) & dd->enable_mask;
774 	v >>= __ffs(dd->enable_mask);
775 	if ((v != OMAP3XXX_EN_DPLL_LOCKED) || (dd->flags & DPLL_J_TYPE))
776 		rate = parent_rate;
777 	else
778 		rate = parent_rate * 2;
779 	return rate;
780 }
781 
782 /**
783  * omap3_core_dpll_save_context - Save the m and n values of the divider
784  * @hw: pointer  struct clk_hw
785  *
786  * Before the dpll registers are lost save the last rounded rate m and n
787  * and the enable mask.
788  */
omap3_core_dpll_save_context(struct clk_hw * hw)789 int omap3_core_dpll_save_context(struct clk_hw *hw)
790 {
791 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
792 	struct dpll_data *dd;
793 	u32 v;
794 
795 	dd = clk->dpll_data;
796 
797 	v = ti_clk_ll_ops->clk_readl(&dd->control_reg);
798 	clk->context = (v & dd->enable_mask) >> __ffs(dd->enable_mask);
799 
800 	if (clk->context == DPLL_LOCKED) {
801 		v = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
802 		dd->last_rounded_m = (v & dd->mult_mask) >>
803 						__ffs(dd->mult_mask);
804 		dd->last_rounded_n = ((v & dd->div1_mask) >>
805 						__ffs(dd->div1_mask)) + 1;
806 	}
807 
808 	return 0;
809 }
810 
811 /**
812  * omap3_core_dpll_restore_context - restore the m and n values of the divider
813  * @hw: pointer  struct clk_hw
814  *
815  * Restore the last rounded rate m and n
816  * and the enable mask.
817  */
omap3_core_dpll_restore_context(struct clk_hw * hw)818 void omap3_core_dpll_restore_context(struct clk_hw *hw)
819 {
820 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
821 	const struct dpll_data *dd;
822 	u32 v;
823 
824 	dd = clk->dpll_data;
825 
826 	if (clk->context == DPLL_LOCKED) {
827 		_omap3_dpll_write_clken(clk, 0x4);
828 		_omap3_wait_dpll_status(clk, 0);
829 
830 		v = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
831 		v &= ~(dd->mult_mask | dd->div1_mask);
832 		v |= dd->last_rounded_m << __ffs(dd->mult_mask);
833 		v |= (dd->last_rounded_n - 1) << __ffs(dd->div1_mask);
834 		ti_clk_ll_ops->clk_writel(v, &dd->mult_div1_reg);
835 
836 		_omap3_dpll_write_clken(clk, DPLL_LOCKED);
837 		_omap3_wait_dpll_status(clk, 1);
838 	} else {
839 		_omap3_dpll_write_clken(clk, clk->context);
840 	}
841 }
842 
843 /**
844  * omap3_non_core_dpll_save_context - Save the m and n values of the divider
845  * @hw: pointer  struct clk_hw
846  *
847  * Before the dpll registers are lost save the last rounded rate m and n
848  * and the enable mask.
849  */
omap3_noncore_dpll_save_context(struct clk_hw * hw)850 int omap3_noncore_dpll_save_context(struct clk_hw *hw)
851 {
852 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
853 	struct dpll_data *dd;
854 	u32 v;
855 
856 	dd = clk->dpll_data;
857 
858 	v = ti_clk_ll_ops->clk_readl(&dd->control_reg);
859 	clk->context = (v & dd->enable_mask) >> __ffs(dd->enable_mask);
860 
861 	if (clk->context == DPLL_LOCKED) {
862 		v = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
863 		dd->last_rounded_m = (v & dd->mult_mask) >>
864 						__ffs(dd->mult_mask);
865 		dd->last_rounded_n = ((v & dd->div1_mask) >>
866 						__ffs(dd->div1_mask)) + 1;
867 	}
868 
869 	return 0;
870 }
871 
872 /**
873  * omap3_core_dpll_restore_context - restore the m and n values of the divider
874  * @hw: pointer  struct clk_hw
875  *
876  * Restore the last rounded rate m and n
877  * and the enable mask.
878  */
omap3_noncore_dpll_restore_context(struct clk_hw * hw)879 void omap3_noncore_dpll_restore_context(struct clk_hw *hw)
880 {
881 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
882 	const struct dpll_data *dd;
883 	u32 ctrl, mult_div1;
884 
885 	dd = clk->dpll_data;
886 
887 	ctrl = ti_clk_ll_ops->clk_readl(&dd->control_reg);
888 	mult_div1 = ti_clk_ll_ops->clk_readl(&dd->mult_div1_reg);
889 
890 	if (clk->context == ((ctrl & dd->enable_mask) >>
891 			     __ffs(dd->enable_mask)) &&
892 	    dd->last_rounded_m == ((mult_div1 & dd->mult_mask) >>
893 				   __ffs(dd->mult_mask)) &&
894 	    dd->last_rounded_n == ((mult_div1 & dd->div1_mask) >>
895 				   __ffs(dd->div1_mask)) + 1) {
896 		/* nothing to be done */
897 		return;
898 	}
899 
900 	if (clk->context == DPLL_LOCKED)
901 		omap3_noncore_dpll_program(clk, 0);
902 	else
903 		_omap3_dpll_write_clken(clk, clk->context);
904 }
905 
906 /* OMAP3/4 non-CORE DPLL clkops */
907 const struct clk_hw_omap_ops clkhwops_omap3_dpll = {
908 	.allow_idle	= omap3_dpll_allow_idle,
909 	.deny_idle	= omap3_dpll_deny_idle,
910 };
911 
912 /**
913  * omap3_dpll4_set_rate - set rate for omap3 per-dpll
914  * @hw: clock to change
915  * @rate: target rate for clock
916  * @parent_rate: rate of the parent clock
917  *
918  * Check if the current SoC supports the per-dpll reprogram operation
919  * or not, and then do the rate change if supported. Returns -EINVAL
920  * if not supported, 0 for success, and potential error codes from the
921  * clock rate change.
922  */
omap3_dpll4_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)923 int omap3_dpll4_set_rate(struct clk_hw *hw, unsigned long rate,
924 			 unsigned long parent_rate)
925 {
926 	/*
927 	 * According to the 12-5 CDP code from TI, "Limitation 2.5"
928 	 * on 3430ES1 prevents us from changing DPLL multipliers or dividers
929 	 * on DPLL4.
930 	 */
931 	if (ti_clk_get_features()->flags & TI_CLK_DPLL4_DENY_REPROGRAM) {
932 		pr_err("clock: DPLL4 cannot change rate due to silicon 'Limitation 2.5' on 3430ES1.\n");
933 		return -EINVAL;
934 	}
935 
936 	return omap3_noncore_dpll_set_rate(hw, rate, parent_rate);
937 }
938 
939 /**
940  * omap3_dpll4_set_rate_and_parent - set rate and parent for omap3 per-dpll
941  * @hw: clock to change
942  * @rate: target rate for clock
943  * @parent_rate: rate of the parent clock
944  * @index: parent index, 0 - reference clock, 1 - bypass clock
945  *
946  * Check if the current SoC support the per-dpll reprogram operation
947  * or not, and then do the rate + parent change if supported. Returns
948  * -EINVAL if not supported, 0 for success, and potential error codes
949  * from the clock rate change.
950  */
omap3_dpll4_set_rate_and_parent(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate,u8 index)951 int omap3_dpll4_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
952 				    unsigned long parent_rate, u8 index)
953 {
954 	if (ti_clk_get_features()->flags & TI_CLK_DPLL4_DENY_REPROGRAM) {
955 		pr_err("clock: DPLL4 cannot change rate due to silicon 'Limitation 2.5' on 3430ES1.\n");
956 		return -EINVAL;
957 	}
958 
959 	return omap3_noncore_dpll_set_rate_and_parent(hw, rate, parent_rate,
960 						      index);
961 }
962 
963 /* Apply DM3730 errata sprz319 advisory 2.1. */
omap3_dpll5_apply_errata(struct clk_hw * hw,unsigned long parent_rate)964 static bool omap3_dpll5_apply_errata(struct clk_hw *hw,
965 				     unsigned long parent_rate)
966 {
967 	struct omap3_dpll5_settings {
968 		unsigned int rate, m, n;
969 	};
970 
971 	static const struct omap3_dpll5_settings precomputed[] = {
972 		/*
973 		 * From DM3730 errata advisory 2.1, table 35 and 36.
974 		 * The N value is increased by 1 compared to the tables as the
975 		 * errata lists register values while last_rounded_field is the
976 		 * real divider value.
977 		 */
978 		{ 12000000,  80,  0 + 1 },
979 		{ 13000000, 443,  5 + 1 },
980 		{ 19200000,  50,  0 + 1 },
981 		{ 26000000, 443, 11 + 1 },
982 		{ 38400000,  25,  0 + 1 }
983 	};
984 
985 	const struct omap3_dpll5_settings *d;
986 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
987 	struct dpll_data *dd;
988 	unsigned int i;
989 
990 	for (i = 0; i < ARRAY_SIZE(precomputed); ++i) {
991 		if (parent_rate == precomputed[i].rate)
992 			break;
993 	}
994 
995 	if (i == ARRAY_SIZE(precomputed))
996 		return false;
997 
998 	d = &precomputed[i];
999 
1000 	/* Update the M, N and rounded rate values and program the DPLL. */
1001 	dd = clk->dpll_data;
1002 	dd->last_rounded_m = d->m;
1003 	dd->last_rounded_n = d->n;
1004 	dd->last_rounded_rate = div_u64((u64)parent_rate * d->m, d->n);
1005 	omap3_noncore_dpll_program(clk, 0);
1006 
1007 	return true;
1008 }
1009 
1010 /**
1011  * omap3_dpll5_set_rate - set rate for omap3 dpll5
1012  * @hw: clock to change
1013  * @rate: target rate for clock
1014  * @parent_rate: rate of the parent clock
1015  *
1016  * Set rate for the DPLL5 clock. Apply the sprz319 advisory 2.1 on OMAP36xx if
1017  * the DPLL is used for USB host (detected through the requested rate).
1018  */
omap3_dpll5_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)1019 int omap3_dpll5_set_rate(struct clk_hw *hw, unsigned long rate,
1020 			 unsigned long parent_rate)
1021 {
1022 	if (rate == OMAP3_DPLL5_FREQ_FOR_USBHOST * 8) {
1023 		if (omap3_dpll5_apply_errata(hw, parent_rate))
1024 			return 0;
1025 	}
1026 
1027 	return omap3_noncore_dpll_set_rate(hw, rate, parent_rate);
1028 }
1029