1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2014 Google, Inc.
4 */
5
6#define pr_fmt(fmt) "%s: " fmt, __func__
7
8#include <linux/clk-provider.h>
9#include <linux/io.h>
10#include <linux/kernel.h>
11#include <linux/printk.h>
12#include <linux/slab.h>
13
14#include "clk.h"
15
16#define PLL_STATUS			0x0
17#define PLL_STATUS_LOCK			BIT(0)
18
19#define PLL_CTRL1			0x4
20#define PLL_CTRL1_REFDIV_SHIFT		0
21#define PLL_CTRL1_REFDIV_MASK		0x3f
22#define PLL_CTRL1_FBDIV_SHIFT		6
23#define PLL_CTRL1_FBDIV_MASK		0xfff
24#define PLL_INT_CTRL1_POSTDIV1_SHIFT	18
25#define PLL_INT_CTRL1_POSTDIV1_MASK	0x7
26#define PLL_INT_CTRL1_POSTDIV2_SHIFT	21
27#define PLL_INT_CTRL1_POSTDIV2_MASK	0x7
28#define PLL_INT_CTRL1_PD		BIT(24)
29#define PLL_INT_CTRL1_DSMPD		BIT(25)
30#define PLL_INT_CTRL1_FOUTPOSTDIVPD	BIT(26)
31#define PLL_INT_CTRL1_FOUTVCOPD		BIT(27)
32
33#define PLL_CTRL2			0x8
34#define PLL_FRAC_CTRL2_FRAC_SHIFT	0
35#define PLL_FRAC_CTRL2_FRAC_MASK	0xffffff
36#define PLL_FRAC_CTRL2_POSTDIV1_SHIFT	24
37#define PLL_FRAC_CTRL2_POSTDIV1_MASK	0x7
38#define PLL_FRAC_CTRL2_POSTDIV2_SHIFT	27
39#define PLL_FRAC_CTRL2_POSTDIV2_MASK	0x7
40#define PLL_INT_CTRL2_BYPASS		BIT(28)
41
42#define PLL_CTRL3			0xc
43#define PLL_FRAC_CTRL3_PD		BIT(0)
44#define PLL_FRAC_CTRL3_DACPD		BIT(1)
45#define PLL_FRAC_CTRL3_DSMPD		BIT(2)
46#define PLL_FRAC_CTRL3_FOUTPOSTDIVPD	BIT(3)
47#define PLL_FRAC_CTRL3_FOUT4PHASEPD	BIT(4)
48#define PLL_FRAC_CTRL3_FOUTVCOPD	BIT(5)
49
50#define PLL_CTRL4			0x10
51#define PLL_FRAC_CTRL4_BYPASS		BIT(28)
52
53#define MIN_PFD				9600000UL
54#define MIN_VCO_LA			400000000UL
55#define MAX_VCO_LA			1600000000UL
56#define MIN_VCO_FRAC_INT		600000000UL
57#define MAX_VCO_FRAC_INT		1600000000UL
58#define MIN_VCO_FRAC_FRAC		600000000UL
59#define MAX_VCO_FRAC_FRAC		2400000000UL
60#define MIN_OUTPUT_LA			8000000UL
61#define MAX_OUTPUT_LA			1600000000UL
62#define MIN_OUTPUT_FRAC			12000000UL
63#define MAX_OUTPUT_FRAC			1600000000UL
64
65/* Fractional PLL operating modes */
66enum pll_mode {
67	PLL_MODE_FRAC,
68	PLL_MODE_INT,
69};
70
71struct pistachio_clk_pll {
72	struct clk_hw hw;
73	void __iomem *base;
74	struct pistachio_pll_rate_table *rates;
75	unsigned int nr_rates;
76};
77
78static inline u32 pll_readl(struct pistachio_clk_pll *pll, u32 reg)
79{
80	return readl(pll->base + reg);
81}
82
83static inline void pll_writel(struct pistachio_clk_pll *pll, u32 val, u32 reg)
84{
85	writel(val, pll->base + reg);
86}
87
88static inline void pll_lock(struct pistachio_clk_pll *pll)
89{
90	while (!(pll_readl(pll, PLL_STATUS) & PLL_STATUS_LOCK))
91		cpu_relax();
92}
93
94static inline u64 do_div_round_closest(u64 dividend, u64 divisor)
95{
96	dividend += divisor / 2;
97	return div64_u64(dividend, divisor);
98}
99
100static inline struct pistachio_clk_pll *to_pistachio_pll(struct clk_hw *hw)
101{
102	return container_of(hw, struct pistachio_clk_pll, hw);
103}
104
105static inline enum pll_mode pll_frac_get_mode(struct clk_hw *hw)
106{
107	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
108	u32 val;
109
110	val = pll_readl(pll, PLL_CTRL3) & PLL_FRAC_CTRL3_DSMPD;
111	return val ? PLL_MODE_INT : PLL_MODE_FRAC;
112}
113
114static inline void pll_frac_set_mode(struct clk_hw *hw, enum pll_mode mode)
115{
116	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
117	u32 val;
118
119	val = pll_readl(pll, PLL_CTRL3);
120	if (mode == PLL_MODE_INT)
121		val |= PLL_FRAC_CTRL3_DSMPD | PLL_FRAC_CTRL3_DACPD;
122	else
123		val &= ~(PLL_FRAC_CTRL3_DSMPD | PLL_FRAC_CTRL3_DACPD);
124
125	pll_writel(pll, val, PLL_CTRL3);
126}
127
128static struct pistachio_pll_rate_table *
129pll_get_params(struct pistachio_clk_pll *pll, unsigned long fref,
130	       unsigned long fout)
131{
132	unsigned int i;
133
134	for (i = 0; i < pll->nr_rates; i++) {
135		if (pll->rates[i].fref == fref && pll->rates[i].fout == fout)
136			return &pll->rates[i];
137	}
138
139	return NULL;
140}
141
142static long pll_round_rate(struct clk_hw *hw, unsigned long rate,
143			   unsigned long *parent_rate)
144{
145	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
146	unsigned int i;
147
148	for (i = 0; i < pll->nr_rates; i++) {
149		if (i > 0 && pll->rates[i].fref == *parent_rate &&
150		    pll->rates[i].fout <= rate)
151			return pll->rates[i - 1].fout;
152	}
153
154	return pll->rates[0].fout;
155}
156
157static int pll_gf40lp_frac_enable(struct clk_hw *hw)
158{
159	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
160	u32 val;
161
162	val = pll_readl(pll, PLL_CTRL3);
163	val &= ~(PLL_FRAC_CTRL3_PD | PLL_FRAC_CTRL3_FOUTPOSTDIVPD |
164		 PLL_FRAC_CTRL3_FOUT4PHASEPD | PLL_FRAC_CTRL3_FOUTVCOPD);
165	pll_writel(pll, val, PLL_CTRL3);
166
167	val = pll_readl(pll, PLL_CTRL4);
168	val &= ~PLL_FRAC_CTRL4_BYPASS;
169	pll_writel(pll, val, PLL_CTRL4);
170
171	pll_lock(pll);
172
173	return 0;
174}
175
176static void pll_gf40lp_frac_disable(struct clk_hw *hw)
177{
178	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
179	u32 val;
180
181	val = pll_readl(pll, PLL_CTRL3);
182	val |= PLL_FRAC_CTRL3_PD;
183	pll_writel(pll, val, PLL_CTRL3);
184}
185
186static int pll_gf40lp_frac_is_enabled(struct clk_hw *hw)
187{
188	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
189
190	return !(pll_readl(pll, PLL_CTRL3) & PLL_FRAC_CTRL3_PD);
191}
192
193static int pll_gf40lp_frac_set_rate(struct clk_hw *hw, unsigned long rate,
194				    unsigned long parent_rate)
195{
196	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
197	struct pistachio_pll_rate_table *params;
198	int enabled = pll_gf40lp_frac_is_enabled(hw);
199	u64 val, vco, old_postdiv1, old_postdiv2;
200	const char *name = clk_hw_get_name(hw);
201
202	if (rate < MIN_OUTPUT_FRAC || rate > MAX_OUTPUT_FRAC)
203		return -EINVAL;
204
205	params = pll_get_params(pll, parent_rate, rate);
206	if (!params || !params->refdiv)
207		return -EINVAL;
208
209	/* calculate vco */
210	vco = params->fref;
211	vco *= (params->fbdiv << 24) + params->frac;
212	vco = div64_u64(vco, params->refdiv << 24);
213
214	if (vco < MIN_VCO_FRAC_FRAC || vco > MAX_VCO_FRAC_FRAC)
215		pr_warn("%s: VCO %llu is out of range %lu..%lu\n", name, vco,
216			MIN_VCO_FRAC_FRAC, MAX_VCO_FRAC_FRAC);
217
218	val = div64_u64(params->fref, params->refdiv);
219	if (val < MIN_PFD)
220		pr_warn("%s: PFD %llu is too low (min %lu)\n",
221			name, val, MIN_PFD);
222	if (val > vco / 16)
223		pr_warn("%s: PFD %llu is too high (max %llu)\n",
224			name, val, vco / 16);
225
226	val = pll_readl(pll, PLL_CTRL1);
227	val &= ~((PLL_CTRL1_REFDIV_MASK << PLL_CTRL1_REFDIV_SHIFT) |
228		 (PLL_CTRL1_FBDIV_MASK << PLL_CTRL1_FBDIV_SHIFT));
229	val |= (params->refdiv << PLL_CTRL1_REFDIV_SHIFT) |
230		(params->fbdiv << PLL_CTRL1_FBDIV_SHIFT);
231	pll_writel(pll, val, PLL_CTRL1);
232
233	val = pll_readl(pll, PLL_CTRL2);
234
235	old_postdiv1 = (val >> PLL_FRAC_CTRL2_POSTDIV1_SHIFT) &
236		       PLL_FRAC_CTRL2_POSTDIV1_MASK;
237	old_postdiv2 = (val >> PLL_FRAC_CTRL2_POSTDIV2_SHIFT) &
238		       PLL_FRAC_CTRL2_POSTDIV2_MASK;
239	if (enabled &&
240	    (params->postdiv1 != old_postdiv1 ||
241	     params->postdiv2 != old_postdiv2))
242		pr_warn("%s: changing postdiv while PLL is enabled\n", name);
243
244	if (params->postdiv2 > params->postdiv1)
245		pr_warn("%s: postdiv2 should not exceed postdiv1\n", name);
246
247	val &= ~((PLL_FRAC_CTRL2_FRAC_MASK << PLL_FRAC_CTRL2_FRAC_SHIFT) |
248		 (PLL_FRAC_CTRL2_POSTDIV1_MASK <<
249		  PLL_FRAC_CTRL2_POSTDIV1_SHIFT) |
250		 (PLL_FRAC_CTRL2_POSTDIV2_MASK <<
251		  PLL_FRAC_CTRL2_POSTDIV2_SHIFT));
252	val |= (params->frac << PLL_FRAC_CTRL2_FRAC_SHIFT) |
253		(params->postdiv1 << PLL_FRAC_CTRL2_POSTDIV1_SHIFT) |
254		(params->postdiv2 << PLL_FRAC_CTRL2_POSTDIV2_SHIFT);
255	pll_writel(pll, val, PLL_CTRL2);
256
257	/* set operating mode */
258	if (params->frac)
259		pll_frac_set_mode(hw, PLL_MODE_FRAC);
260	else
261		pll_frac_set_mode(hw, PLL_MODE_INT);
262
263	if (enabled)
264		pll_lock(pll);
265
266	return 0;
267}
268
269static unsigned long pll_gf40lp_frac_recalc_rate(struct clk_hw *hw,
270						 unsigned long parent_rate)
271{
272	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
273	u64 val, prediv, fbdiv, frac, postdiv1, postdiv2, rate;
274
275	val = pll_readl(pll, PLL_CTRL1);
276	prediv = (val >> PLL_CTRL1_REFDIV_SHIFT) & PLL_CTRL1_REFDIV_MASK;
277	fbdiv = (val >> PLL_CTRL1_FBDIV_SHIFT) & PLL_CTRL1_FBDIV_MASK;
278
279	val = pll_readl(pll, PLL_CTRL2);
280	postdiv1 = (val >> PLL_FRAC_CTRL2_POSTDIV1_SHIFT) &
281		PLL_FRAC_CTRL2_POSTDIV1_MASK;
282	postdiv2 = (val >> PLL_FRAC_CTRL2_POSTDIV2_SHIFT) &
283		PLL_FRAC_CTRL2_POSTDIV2_MASK;
284	frac = (val >> PLL_FRAC_CTRL2_FRAC_SHIFT) & PLL_FRAC_CTRL2_FRAC_MASK;
285
286	/* get operating mode (int/frac) and calculate rate accordingly */
287	rate = parent_rate;
288	if (pll_frac_get_mode(hw) == PLL_MODE_FRAC)
289		rate *= (fbdiv << 24) + frac;
290	else
291		rate *= (fbdiv << 24);
292
293	rate = do_div_round_closest(rate, (prediv * postdiv1 * postdiv2) << 24);
294
295	return rate;
296}
297
298static const struct clk_ops pll_gf40lp_frac_ops = {
299	.enable = pll_gf40lp_frac_enable,
300	.disable = pll_gf40lp_frac_disable,
301	.is_enabled = pll_gf40lp_frac_is_enabled,
302	.recalc_rate = pll_gf40lp_frac_recalc_rate,
303	.round_rate = pll_round_rate,
304	.set_rate = pll_gf40lp_frac_set_rate,
305};
306
307static const struct clk_ops pll_gf40lp_frac_fixed_ops = {
308	.enable = pll_gf40lp_frac_enable,
309	.disable = pll_gf40lp_frac_disable,
310	.is_enabled = pll_gf40lp_frac_is_enabled,
311	.recalc_rate = pll_gf40lp_frac_recalc_rate,
312};
313
314static int pll_gf40lp_laint_enable(struct clk_hw *hw)
315{
316	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
317	u32 val;
318
319	val = pll_readl(pll, PLL_CTRL1);
320	val &= ~(PLL_INT_CTRL1_PD |
321		 PLL_INT_CTRL1_FOUTPOSTDIVPD | PLL_INT_CTRL1_FOUTVCOPD);
322	pll_writel(pll, val, PLL_CTRL1);
323
324	val = pll_readl(pll, PLL_CTRL2);
325	val &= ~PLL_INT_CTRL2_BYPASS;
326	pll_writel(pll, val, PLL_CTRL2);
327
328	pll_lock(pll);
329
330	return 0;
331}
332
333static void pll_gf40lp_laint_disable(struct clk_hw *hw)
334{
335	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
336	u32 val;
337
338	val = pll_readl(pll, PLL_CTRL1);
339	val |= PLL_INT_CTRL1_PD;
340	pll_writel(pll, val, PLL_CTRL1);
341}
342
343static int pll_gf40lp_laint_is_enabled(struct clk_hw *hw)
344{
345	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
346
347	return !(pll_readl(pll, PLL_CTRL1) & PLL_INT_CTRL1_PD);
348}
349
350static int pll_gf40lp_laint_set_rate(struct clk_hw *hw, unsigned long rate,
351				     unsigned long parent_rate)
352{
353	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
354	struct pistachio_pll_rate_table *params;
355	int enabled = pll_gf40lp_laint_is_enabled(hw);
356	u32 val, vco, old_postdiv1, old_postdiv2;
357	const char *name = clk_hw_get_name(hw);
358
359	if (rate < MIN_OUTPUT_LA || rate > MAX_OUTPUT_LA)
360		return -EINVAL;
361
362	params = pll_get_params(pll, parent_rate, rate);
363	if (!params || !params->refdiv)
364		return -EINVAL;
365
366	vco = div_u64(params->fref * params->fbdiv, params->refdiv);
367	if (vco < MIN_VCO_LA || vco > MAX_VCO_LA)
368		pr_warn("%s: VCO %u is out of range %lu..%lu\n", name, vco,
369			MIN_VCO_LA, MAX_VCO_LA);
370
371	val = div_u64(params->fref, params->refdiv);
372	if (val < MIN_PFD)
373		pr_warn("%s: PFD %u is too low (min %lu)\n",
374			name, val, MIN_PFD);
375	if (val > vco / 16)
376		pr_warn("%s: PFD %u is too high (max %u)\n",
377			name, val, vco / 16);
378
379	val = pll_readl(pll, PLL_CTRL1);
380
381	old_postdiv1 = (val >> PLL_INT_CTRL1_POSTDIV1_SHIFT) &
382		       PLL_INT_CTRL1_POSTDIV1_MASK;
383	old_postdiv2 = (val >> PLL_INT_CTRL1_POSTDIV2_SHIFT) &
384		       PLL_INT_CTRL1_POSTDIV2_MASK;
385	if (enabled &&
386	    (params->postdiv1 != old_postdiv1 ||
387	     params->postdiv2 != old_postdiv2))
388		pr_warn("%s: changing postdiv while PLL is enabled\n", name);
389
390	if (params->postdiv2 > params->postdiv1)
391		pr_warn("%s: postdiv2 should not exceed postdiv1\n", name);
392
393	val &= ~((PLL_CTRL1_REFDIV_MASK << PLL_CTRL1_REFDIV_SHIFT) |
394		 (PLL_CTRL1_FBDIV_MASK << PLL_CTRL1_FBDIV_SHIFT) |
395		 (PLL_INT_CTRL1_POSTDIV1_MASK << PLL_INT_CTRL1_POSTDIV1_SHIFT) |
396		 (PLL_INT_CTRL1_POSTDIV2_MASK << PLL_INT_CTRL1_POSTDIV2_SHIFT));
397	val |= (params->refdiv << PLL_CTRL1_REFDIV_SHIFT) |
398		(params->fbdiv << PLL_CTRL1_FBDIV_SHIFT) |
399		(params->postdiv1 << PLL_INT_CTRL1_POSTDIV1_SHIFT) |
400		(params->postdiv2 << PLL_INT_CTRL1_POSTDIV2_SHIFT);
401	pll_writel(pll, val, PLL_CTRL1);
402
403	if (enabled)
404		pll_lock(pll);
405
406	return 0;
407}
408
409static unsigned long pll_gf40lp_laint_recalc_rate(struct clk_hw *hw,
410						  unsigned long parent_rate)
411{
412	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
413	u32 val, prediv, fbdiv, postdiv1, postdiv2;
414	u64 rate = parent_rate;
415
416	val = pll_readl(pll, PLL_CTRL1);
417	prediv = (val >> PLL_CTRL1_REFDIV_SHIFT) & PLL_CTRL1_REFDIV_MASK;
418	fbdiv = (val >> PLL_CTRL1_FBDIV_SHIFT) & PLL_CTRL1_FBDIV_MASK;
419	postdiv1 = (val >> PLL_INT_CTRL1_POSTDIV1_SHIFT) &
420		PLL_INT_CTRL1_POSTDIV1_MASK;
421	postdiv2 = (val >> PLL_INT_CTRL1_POSTDIV2_SHIFT) &
422		PLL_INT_CTRL1_POSTDIV2_MASK;
423
424	rate *= fbdiv;
425	rate = do_div_round_closest(rate, prediv * postdiv1 * postdiv2);
426
427	return rate;
428}
429
430static const struct clk_ops pll_gf40lp_laint_ops = {
431	.enable = pll_gf40lp_laint_enable,
432	.disable = pll_gf40lp_laint_disable,
433	.is_enabled = pll_gf40lp_laint_is_enabled,
434	.recalc_rate = pll_gf40lp_laint_recalc_rate,
435	.round_rate = pll_round_rate,
436	.set_rate = pll_gf40lp_laint_set_rate,
437};
438
439static const struct clk_ops pll_gf40lp_laint_fixed_ops = {
440	.enable = pll_gf40lp_laint_enable,
441	.disable = pll_gf40lp_laint_disable,
442	.is_enabled = pll_gf40lp_laint_is_enabled,
443	.recalc_rate = pll_gf40lp_laint_recalc_rate,
444};
445
446static struct clk *pll_register(const char *name, const char *parent_name,
447				unsigned long flags, void __iomem *base,
448				enum pistachio_pll_type type,
449				struct pistachio_pll_rate_table *rates,
450				unsigned int nr_rates)
451{
452	struct pistachio_clk_pll *pll;
453	struct clk_init_data init;
454	struct clk *clk;
455
456	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
457	if (!pll)
458		return ERR_PTR(-ENOMEM);
459
460	init.name = name;
461	init.flags = flags | CLK_GET_RATE_NOCACHE;
462	init.parent_names = &parent_name;
463	init.num_parents = 1;
464
465	switch (type) {
466	case PLL_GF40LP_FRAC:
467		if (rates)
468			init.ops = &pll_gf40lp_frac_ops;
469		else
470			init.ops = &pll_gf40lp_frac_fixed_ops;
471		break;
472	case PLL_GF40LP_LAINT:
473		if (rates)
474			init.ops = &pll_gf40lp_laint_ops;
475		else
476			init.ops = &pll_gf40lp_laint_fixed_ops;
477		break;
478	default:
479		pr_err("Unrecognized PLL type %u\n", type);
480		kfree(pll);
481		return ERR_PTR(-EINVAL);
482	}
483
484	pll->hw.init = &init;
485	pll->base = base;
486	pll->rates = rates;
487	pll->nr_rates = nr_rates;
488
489	clk = clk_register(NULL, &pll->hw);
490	if (IS_ERR(clk))
491		kfree(pll);
492
493	return clk;
494}
495
496void pistachio_clk_register_pll(struct pistachio_clk_provider *p,
497				struct pistachio_pll *pll,
498				unsigned int num)
499{
500	struct clk *clk;
501	unsigned int i;
502
503	for (i = 0; i < num; i++) {
504		clk = pll_register(pll[i].name, pll[i].parent,
505				   0, p->base + pll[i].reg_base,
506				   pll[i].type, pll[i].rates,
507				   pll[i].nr_rates);
508		p->clk_data.clks[pll[i].id] = clk;
509	}
510}
511