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(addr: pll->base + reg);
81}
82
83static inline void pll_writel(struct pistachio_clk_pll *pll, u32 val, u32 reg)
84{
85 writel(val, addr: 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, fref: parent_rate, fout: 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(dividend: vco, divisor: 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(dividend: params->fref, divisor: 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, mode: PLL_MODE_FRAC);
260 else
261 pll_frac_set_mode(hw, mode: 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(dividend: rate, divisor: (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, fref: parent_rate, fout: rate);
363 if (!params || !params->refdiv)
364 return -EINVAL;
365
366 vco = div_u64(dividend: params->fref * params->fbdiv, divisor: 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(dividend: params->fref, divisor: 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(dividend: rate, divisor: 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(size: sizeof(*pll), GFP_KERNEL);
457 if (!pll)
458 return ERR_PTR(error: -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(objp: pll);
481 return ERR_PTR(error: -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, hw: &pll->hw);
490 if (IS_ERR(ptr: clk))
491 kfree(objp: 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(name: pll[i].name, parent_name: pll[i].parent,
505 flags: 0, base: p->base + pll[i].reg_base,
506 type: pll[i].type, rates: pll[i].rates,
507 nr_rates: pll[i].nr_rates);
508 p->clk_data.clks[pll[i].id] = clk;
509 }
510}
511

source code of linux/drivers/clk/pistachio/clk-pll.c