1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright 2017-2018 NXP.
4 */
5
6#define pr_fmt(fmt) "pll14xx: " fmt
7
8#include <linux/bitfield.h>
9#include <linux/bits.h>
10#include <linux/clk-provider.h>
11#include <linux/err.h>
12#include <linux/export.h>
13#include <linux/io.h>
14#include <linux/iopoll.h>
15#include <linux/slab.h>
16#include <linux/jiffies.h>
17
18#include "clk.h"
19
20#define GNRL_CTL	0x0
21#define DIV_CTL0	0x4
22#define DIV_CTL1	0x8
23#define LOCK_STATUS	BIT(31)
24#define LOCK_SEL_MASK	BIT(29)
25#define CLKE_MASK	BIT(11)
26#define RST_MASK	BIT(9)
27#define BYPASS_MASK	BIT(4)
28#define MDIV_MASK	GENMASK(21, 12)
29#define PDIV_MASK	GENMASK(9, 4)
30#define SDIV_MASK	GENMASK(2, 0)
31#define KDIV_MASK	GENMASK(15, 0)
32#define KDIV_MIN	SHRT_MIN
33#define KDIV_MAX	SHRT_MAX
34
35#define LOCK_TIMEOUT_US		10000
36
37struct clk_pll14xx {
38	struct clk_hw			hw;
39	void __iomem			*base;
40	enum imx_pll14xx_type		type;
41	const struct imx_pll14xx_rate_table *rate_table;
42	int rate_count;
43};
44
45#define to_clk_pll14xx(_hw) container_of(_hw, struct clk_pll14xx, hw)
46
47static const struct imx_pll14xx_rate_table imx_pll1416x_tbl[] = {
48	PLL_1416X_RATE(1800000000U, 225, 3, 0),
49	PLL_1416X_RATE(1600000000U, 200, 3, 0),
50	PLL_1416X_RATE(1500000000U, 375, 3, 1),
51	PLL_1416X_RATE(1400000000U, 350, 3, 1),
52	PLL_1416X_RATE(1200000000U, 300, 3, 1),
53	PLL_1416X_RATE(1000000000U, 250, 3, 1),
54	PLL_1416X_RATE(800000000U,  200, 3, 1),
55	PLL_1416X_RATE(750000000U,  250, 2, 2),
56	PLL_1416X_RATE(700000000U,  350, 3, 2),
57	PLL_1416X_RATE(640000000U,  320, 3, 2),
58	PLL_1416X_RATE(600000000U,  300, 3, 2),
59	PLL_1416X_RATE(320000000U,  160, 3, 2),
60};
61
62static const struct imx_pll14xx_rate_table imx_pll1443x_tbl[] = {
63	PLL_1443X_RATE(1039500000U, 173, 2, 1, 16384),
64	PLL_1443X_RATE(650000000U, 325, 3, 2, 0),
65	PLL_1443X_RATE(594000000U, 198, 2, 2, 0),
66	PLL_1443X_RATE(519750000U, 173, 2, 2, 16384),
67};
68
69struct imx_pll14xx_clk imx_1443x_pll = {
70	.type = PLL_1443X,
71	.rate_table = imx_pll1443x_tbl,
72	.rate_count = ARRAY_SIZE(imx_pll1443x_tbl),
73};
74EXPORT_SYMBOL_GPL(imx_1443x_pll);
75
76struct imx_pll14xx_clk imx_1443x_dram_pll = {
77	.type = PLL_1443X,
78	.rate_table = imx_pll1443x_tbl,
79	.rate_count = ARRAY_SIZE(imx_pll1443x_tbl),
80	.flags = CLK_GET_RATE_NOCACHE,
81};
82EXPORT_SYMBOL_GPL(imx_1443x_dram_pll);
83
84struct imx_pll14xx_clk imx_1416x_pll = {
85	.type = PLL_1416X,
86	.rate_table = imx_pll1416x_tbl,
87	.rate_count = ARRAY_SIZE(imx_pll1416x_tbl),
88};
89EXPORT_SYMBOL_GPL(imx_1416x_pll);
90
91static const struct imx_pll14xx_rate_table *imx_get_pll_settings(
92		struct clk_pll14xx *pll, unsigned long rate)
93{
94	const struct imx_pll14xx_rate_table *rate_table = pll->rate_table;
95	int i;
96
97	for (i = 0; i < pll->rate_count; i++)
98		if (rate == rate_table[i].rate)
99			return &rate_table[i];
100
101	return NULL;
102}
103
104static long pll14xx_calc_rate(struct clk_pll14xx *pll, int mdiv, int pdiv,
105			      int sdiv, int kdiv, unsigned long prate)
106{
107	u64 fout = prate;
108
109	/* fout = (m * 65536 + k) * Fin / (p * 65536) / (1 << sdiv) */
110	fout *= (mdiv * 65536 + kdiv);
111	pdiv *= 65536;
112
113	do_div(fout, pdiv << sdiv);
114
115	return fout;
116}
117
118static long pll1443x_calc_kdiv(int mdiv, int pdiv, int sdiv,
119		unsigned long rate, unsigned long prate)
120{
121	long kdiv;
122
123	/* calc kdiv = round(rate * pdiv * 65536 * 2^sdiv / prate) - (mdiv * 65536) */
124	kdiv = ((rate * ((pdiv * 65536) << sdiv) + prate / 2) / prate) - (mdiv * 65536);
125
126	return clamp_t(short, kdiv, KDIV_MIN, KDIV_MAX);
127}
128
129static void imx_pll14xx_calc_settings(struct clk_pll14xx *pll, unsigned long rate,
130				      unsigned long prate, struct imx_pll14xx_rate_table *t)
131{
132	u32 pll_div_ctl0, pll_div_ctl1;
133	int mdiv, pdiv, sdiv, kdiv;
134	long fout, rate_min, rate_max, dist, best = LONG_MAX;
135	const struct imx_pll14xx_rate_table *tt;
136
137	/*
138	 * Fractional PLL constrains:
139	 *
140	 * a) 1 <= p <= 63
141	 * b) 64 <= m <= 1023
142	 * c) 0 <= s <= 6
143	 * d) -32768 <= k <= 32767
144	 *
145	 * fvco = (m * 65536 + k) * prate / (p * 65536)
146	 * fout = (m * 65536 + k) * prate / (p * 65536) / (1 << sdiv)
147	 */
148
149	/* First try if we can get the desired rate from one of the static entries */
150	tt = imx_get_pll_settings(pll, rate);
151	if (tt) {
152		pr_debug("%s: in=%ld, want=%ld, Using PLL setting from table\n",
153			 clk_hw_get_name(&pll->hw), prate, rate);
154		t->rate = tt->rate;
155		t->mdiv = tt->mdiv;
156		t->pdiv = tt->pdiv;
157		t->sdiv = tt->sdiv;
158		t->kdiv = tt->kdiv;
159		return;
160	}
161
162	pll_div_ctl0 = readl_relaxed(pll->base + DIV_CTL0);
163	mdiv = FIELD_GET(MDIV_MASK, pll_div_ctl0);
164	pdiv = FIELD_GET(PDIV_MASK, pll_div_ctl0);
165	sdiv = FIELD_GET(SDIV_MASK, pll_div_ctl0);
166	pll_div_ctl1 = readl_relaxed(pll->base + DIV_CTL1);
167
168	/* Then see if we can get the desired rate by only adjusting kdiv (glitch free) */
169	rate_min = pll14xx_calc_rate(pll, mdiv, pdiv, sdiv, KDIV_MIN, prate);
170	rate_max = pll14xx_calc_rate(pll, mdiv, pdiv, sdiv, KDIV_MAX, prate);
171
172	if (rate >= rate_min && rate <= rate_max) {
173		kdiv = pll1443x_calc_kdiv(mdiv, pdiv, sdiv, rate, prate);
174		pr_debug("%s: in=%ld, want=%ld Only adjust kdiv %ld -> %d\n",
175			 clk_hw_get_name(&pll->hw), prate, rate,
176			 FIELD_GET(KDIV_MASK, pll_div_ctl1), kdiv);
177		fout = pll14xx_calc_rate(pll, mdiv, pdiv, sdiv, kdiv, prate);
178		t->rate = (unsigned int)fout;
179		t->mdiv = mdiv;
180		t->pdiv = pdiv;
181		t->sdiv = sdiv;
182		t->kdiv = kdiv;
183		return;
184	}
185
186	/* Finally calculate best values */
187	for (pdiv = 1; pdiv <= 63; pdiv++) {
188		for (sdiv = 0; sdiv <= 6; sdiv++) {
189			/* calc mdiv = round(rate * pdiv * 2^sdiv) / prate) */
190			mdiv = DIV_ROUND_CLOSEST(rate * (pdiv << sdiv), prate);
191			mdiv = clamp(mdiv, 64, 1023);
192
193			kdiv = pll1443x_calc_kdiv(mdiv, pdiv, sdiv, rate, prate);
194			fout = pll14xx_calc_rate(pll, mdiv, pdiv, sdiv, kdiv, prate);
195
196			/* best match */
197			dist = abs((long)rate - (long)fout);
198			if (dist < best) {
199				best = dist;
200				t->rate = (unsigned int)fout;
201				t->mdiv = mdiv;
202				t->pdiv = pdiv;
203				t->sdiv = sdiv;
204				t->kdiv = kdiv;
205
206				if (!dist)
207					goto found;
208			}
209		}
210	}
211found:
212	pr_debug("%s: in=%ld, want=%ld got=%d (pdiv=%d sdiv=%d mdiv=%d kdiv=%d)\n",
213		 clk_hw_get_name(&pll->hw), prate, rate, t->rate, t->pdiv, t->sdiv,
214		 t->mdiv, t->kdiv);
215}
216
217static long clk_pll1416x_round_rate(struct clk_hw *hw, unsigned long rate,
218			unsigned long *prate)
219{
220	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
221	const struct imx_pll14xx_rate_table *rate_table = pll->rate_table;
222	int i;
223
224	/* Assuming rate_table is in descending order */
225	for (i = 0; i < pll->rate_count; i++)
226		if (rate >= rate_table[i].rate)
227			return rate_table[i].rate;
228
229	/* return minimum supported value */
230	return rate_table[pll->rate_count - 1].rate;
231}
232
233static long clk_pll1443x_round_rate(struct clk_hw *hw, unsigned long rate,
234			unsigned long *prate)
235{
236	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
237	struct imx_pll14xx_rate_table t;
238
239	imx_pll14xx_calc_settings(pll, rate, *prate, &t);
240
241	return t.rate;
242}
243
244static unsigned long clk_pll14xx_recalc_rate(struct clk_hw *hw,
245						  unsigned long parent_rate)
246{
247	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
248	u32 mdiv, pdiv, sdiv, kdiv, pll_div_ctl0, pll_div_ctl1;
249
250	pll_div_ctl0 = readl_relaxed(pll->base + DIV_CTL0);
251	mdiv = FIELD_GET(MDIV_MASK, pll_div_ctl0);
252	pdiv = FIELD_GET(PDIV_MASK, pll_div_ctl0);
253	sdiv = FIELD_GET(SDIV_MASK, pll_div_ctl0);
254
255	if (pll->type == PLL_1443X) {
256		pll_div_ctl1 = readl_relaxed(pll->base + DIV_CTL1);
257		kdiv = (s16)FIELD_GET(KDIV_MASK, pll_div_ctl1);
258	} else {
259		kdiv = 0;
260	}
261
262	return pll14xx_calc_rate(pll, mdiv, pdiv, sdiv, kdiv, parent_rate);
263}
264
265static inline bool clk_pll14xx_mp_change(const struct imx_pll14xx_rate_table *rate,
266					  u32 pll_div)
267{
268	u32 old_mdiv, old_pdiv;
269
270	old_mdiv = FIELD_GET(MDIV_MASK, pll_div);
271	old_pdiv = FIELD_GET(PDIV_MASK, pll_div);
272
273	return rate->mdiv != old_mdiv || rate->pdiv != old_pdiv;
274}
275
276static int clk_pll14xx_wait_lock(struct clk_pll14xx *pll)
277{
278	u32 val;
279
280	return readl_poll_timeout(pll->base + GNRL_CTL, val, val & LOCK_STATUS, 0,
281			LOCK_TIMEOUT_US);
282}
283
284static int clk_pll1416x_set_rate(struct clk_hw *hw, unsigned long drate,
285				 unsigned long prate)
286{
287	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
288	const struct imx_pll14xx_rate_table *rate;
289	u32 tmp, div_val;
290	int ret;
291
292	rate = imx_get_pll_settings(pll, drate);
293	if (!rate) {
294		pr_err("Invalid rate %lu for pll clk %s\n", drate,
295		       clk_hw_get_name(hw));
296		return -EINVAL;
297	}
298
299	tmp = readl_relaxed(pll->base + DIV_CTL0);
300
301	if (!clk_pll14xx_mp_change(rate, tmp)) {
302		tmp &= ~SDIV_MASK;
303		tmp |= FIELD_PREP(SDIV_MASK, rate->sdiv);
304		writel_relaxed(tmp, pll->base + DIV_CTL0);
305
306		return 0;
307	}
308
309	/* Bypass clock and set lock to pll output lock */
310	tmp = readl_relaxed(pll->base + GNRL_CTL);
311	tmp |= LOCK_SEL_MASK;
312	writel_relaxed(tmp, pll->base + GNRL_CTL);
313
314	/* Enable RST */
315	tmp &= ~RST_MASK;
316	writel_relaxed(tmp, pll->base + GNRL_CTL);
317
318	/* Enable BYPASS */
319	tmp |= BYPASS_MASK;
320	writel(tmp, pll->base + GNRL_CTL);
321
322	div_val = FIELD_PREP(MDIV_MASK, rate->mdiv) | FIELD_PREP(PDIV_MASK, rate->pdiv) |
323		FIELD_PREP(SDIV_MASK, rate->sdiv);
324	writel_relaxed(div_val, pll->base + DIV_CTL0);
325
326	/*
327	 * According to SPEC, t3 - t2 need to be greater than
328	 * 1us and 1/FREF, respectively.
329	 * FREF is FIN / Prediv, the prediv is [1, 63], so choose
330	 * 3us.
331	 */
332	udelay(3);
333
334	/* Disable RST */
335	tmp |= RST_MASK;
336	writel_relaxed(tmp, pll->base + GNRL_CTL);
337
338	/* Wait Lock */
339	ret = clk_pll14xx_wait_lock(pll);
340	if (ret)
341		return ret;
342
343	/* Bypass */
344	tmp &= ~BYPASS_MASK;
345	writel_relaxed(tmp, pll->base + GNRL_CTL);
346
347	return 0;
348}
349
350static int clk_pll1443x_set_rate(struct clk_hw *hw, unsigned long drate,
351				 unsigned long prate)
352{
353	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
354	struct imx_pll14xx_rate_table rate;
355	u32 gnrl_ctl, div_ctl0;
356	int ret;
357
358	imx_pll14xx_calc_settings(pll, drate, prate, &rate);
359
360	div_ctl0 = readl_relaxed(pll->base + DIV_CTL0);
361
362	if (!clk_pll14xx_mp_change(&rate, div_ctl0)) {
363		/* only sdiv and/or kdiv changed - no need to RESET PLL */
364		div_ctl0 &= ~SDIV_MASK;
365		div_ctl0 |= FIELD_PREP(SDIV_MASK, rate.sdiv);
366		writel_relaxed(div_ctl0, pll->base + DIV_CTL0);
367
368		writel_relaxed(FIELD_PREP(KDIV_MASK, rate.kdiv),
369			       pll->base + DIV_CTL1);
370
371		return 0;
372	}
373
374	/* Enable RST */
375	gnrl_ctl = readl_relaxed(pll->base + GNRL_CTL);
376	gnrl_ctl &= ~RST_MASK;
377	writel_relaxed(gnrl_ctl, pll->base + GNRL_CTL);
378
379	/* Enable BYPASS */
380	gnrl_ctl |= BYPASS_MASK;
381	writel_relaxed(gnrl_ctl, pll->base + GNRL_CTL);
382
383	div_ctl0 = FIELD_PREP(MDIV_MASK, rate.mdiv) |
384		   FIELD_PREP(PDIV_MASK, rate.pdiv) |
385		   FIELD_PREP(SDIV_MASK, rate.sdiv);
386	writel_relaxed(div_ctl0, pll->base + DIV_CTL0);
387
388	writel_relaxed(FIELD_PREP(KDIV_MASK, rate.kdiv), pll->base + DIV_CTL1);
389
390	/*
391	 * According to SPEC, t3 - t2 need to be greater than
392	 * 1us and 1/FREF, respectively.
393	 * FREF is FIN / Prediv, the prediv is [1, 63], so choose
394	 * 3us.
395	 */
396	udelay(3);
397
398	/* Disable RST */
399	gnrl_ctl |= RST_MASK;
400	writel_relaxed(gnrl_ctl, pll->base + GNRL_CTL);
401
402	/* Wait Lock*/
403	ret = clk_pll14xx_wait_lock(pll);
404	if (ret)
405		return ret;
406
407	/* Bypass */
408	gnrl_ctl &= ~BYPASS_MASK;
409	writel_relaxed(gnrl_ctl, pll->base + GNRL_CTL);
410
411	return 0;
412}
413
414static int clk_pll14xx_prepare(struct clk_hw *hw)
415{
416	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
417	u32 val;
418	int ret;
419
420	/*
421	 * RESETB = 1 from 0, PLL starts its normal
422	 * operation after lock time
423	 */
424	val = readl_relaxed(pll->base + GNRL_CTL);
425	if (val & RST_MASK)
426		return 0;
427	val |= BYPASS_MASK;
428	writel_relaxed(val, pll->base + GNRL_CTL);
429	val |= RST_MASK;
430	writel_relaxed(val, pll->base + GNRL_CTL);
431
432	ret = clk_pll14xx_wait_lock(pll);
433	if (ret)
434		return ret;
435
436	val &= ~BYPASS_MASK;
437	writel_relaxed(val, pll->base + GNRL_CTL);
438
439	return 0;
440}
441
442static int clk_pll14xx_is_prepared(struct clk_hw *hw)
443{
444	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
445	u32 val;
446
447	val = readl_relaxed(pll->base + GNRL_CTL);
448
449	return (val & RST_MASK) ? 1 : 0;
450}
451
452static void clk_pll14xx_unprepare(struct clk_hw *hw)
453{
454	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
455	u32 val;
456
457	/*
458	 * Set RST to 0, power down mode is enabled and
459	 * every digital block is reset
460	 */
461	val = readl_relaxed(pll->base + GNRL_CTL);
462	val &= ~RST_MASK;
463	writel_relaxed(val, pll->base + GNRL_CTL);
464}
465
466static const struct clk_ops clk_pll1416x_ops = {
467	.prepare	= clk_pll14xx_prepare,
468	.unprepare	= clk_pll14xx_unprepare,
469	.is_prepared	= clk_pll14xx_is_prepared,
470	.recalc_rate	= clk_pll14xx_recalc_rate,
471	.round_rate	= clk_pll1416x_round_rate,
472	.set_rate	= clk_pll1416x_set_rate,
473};
474
475static const struct clk_ops clk_pll1416x_min_ops = {
476	.recalc_rate	= clk_pll14xx_recalc_rate,
477};
478
479static const struct clk_ops clk_pll1443x_ops = {
480	.prepare	= clk_pll14xx_prepare,
481	.unprepare	= clk_pll14xx_unprepare,
482	.is_prepared	= clk_pll14xx_is_prepared,
483	.recalc_rate	= clk_pll14xx_recalc_rate,
484	.round_rate	= clk_pll1443x_round_rate,
485	.set_rate	= clk_pll1443x_set_rate,
486};
487
488struct clk_hw *imx_dev_clk_hw_pll14xx(struct device *dev, const char *name,
489				const char *parent_name, void __iomem *base,
490				const struct imx_pll14xx_clk *pll_clk)
491{
492	struct clk_pll14xx *pll;
493	struct clk_hw *hw;
494	struct clk_init_data init;
495	int ret;
496	u32 val;
497
498	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
499	if (!pll)
500		return ERR_PTR(-ENOMEM);
501
502	init.name = name;
503	init.flags = pll_clk->flags;
504	init.parent_names = &parent_name;
505	init.num_parents = 1;
506
507	switch (pll_clk->type) {
508	case PLL_1416X:
509		if (!pll_clk->rate_table)
510			init.ops = &clk_pll1416x_min_ops;
511		else
512			init.ops = &clk_pll1416x_ops;
513		break;
514	case PLL_1443X:
515		init.ops = &clk_pll1443x_ops;
516		break;
517	default:
518		pr_err("Unknown pll type for pll clk %s\n", name);
519		kfree(pll);
520		return ERR_PTR(-EINVAL);
521	}
522
523	pll->base = base;
524	pll->hw.init = &init;
525	pll->type = pll_clk->type;
526	pll->rate_table = pll_clk->rate_table;
527	pll->rate_count = pll_clk->rate_count;
528
529	val = readl_relaxed(pll->base + GNRL_CTL);
530	val &= ~BYPASS_MASK;
531	writel_relaxed(val, pll->base + GNRL_CTL);
532
533	hw = &pll->hw;
534
535	ret = clk_hw_register(dev, hw);
536	if (ret) {
537		pr_err("failed to register pll %s %d\n", name, ret);
538		kfree(pll);
539		return ERR_PTR(ret);
540	}
541
542	return hw;
543}
544EXPORT_SYMBOL_GPL(imx_dev_clk_hw_pll14xx);
545