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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AXI clkgen driver
4 *
5 * Copyright 2012-2013 Analog Devices Inc.
6 * Author: Lars-Peter Clausen <lars@metafoo.de>
7 */
8
9#include <linux/platform_device.h>
10#include <linux/clk-provider.h>
11#include <linux/slab.h>
12#include <linux/io.h>
13#include <linux/of.h>
14#include <linux/module.h>
15#include <linux/err.h>
16
17#define AXI_CLKGEN_V2_REG_RESET 0x40
18#define AXI_CLKGEN_V2_REG_CLKSEL 0x44
19#define AXI_CLKGEN_V2_REG_DRP_CNTRL 0x70
20#define AXI_CLKGEN_V2_REG_DRP_STATUS 0x74
21
22#define AXI_CLKGEN_V2_RESET_MMCM_ENABLE BIT(1)
23#define AXI_CLKGEN_V2_RESET_ENABLE BIT(0)
24
25#define AXI_CLKGEN_V2_DRP_CNTRL_SEL BIT(29)
26#define AXI_CLKGEN_V2_DRP_CNTRL_READ BIT(28)
27
28#define AXI_CLKGEN_V2_DRP_STATUS_BUSY BIT(16)
29
30#define MMCM_REG_CLKOUT5_2 0x07
31#define MMCM_REG_CLKOUT0_1 0x08
32#define MMCM_REG_CLKOUT0_2 0x09
33#define MMCM_REG_CLKOUT6_2 0x13
34#define MMCM_REG_CLK_FB1 0x14
35#define MMCM_REG_CLK_FB2 0x15
36#define MMCM_REG_CLK_DIV 0x16
37#define MMCM_REG_LOCK1 0x18
38#define MMCM_REG_LOCK2 0x19
39#define MMCM_REG_LOCK3 0x1a
40#define MMCM_REG_POWER 0x28
41#define MMCM_REG_FILTER1 0x4e
42#define MMCM_REG_FILTER2 0x4f
43
44#define MMCM_CLKOUT_NOCOUNT BIT(6)
45
46#define MMCM_CLK_DIV_DIVIDE BIT(11)
47#define MMCM_CLK_DIV_NOCOUNT BIT(12)
48
49struct axi_clkgen_limits {
50 unsigned int fpfd_min;
51 unsigned int fpfd_max;
52 unsigned int fvco_min;
53 unsigned int fvco_max;
54};
55
56struct axi_clkgen {
57 void __iomem *base;
58 struct clk_hw clk_hw;
59 struct axi_clkgen_limits limits;
60};
61
62static uint32_t axi_clkgen_lookup_filter(unsigned int m)
63{
64 switch (m) {
65 case 0:
66 return 0x01001990;
67 case 1:
68 return 0x01001190;
69 case 2:
70 return 0x01009890;
71 case 3:
72 return 0x01001890;
73 case 4:
74 return 0x01008890;
75 case 5 ... 8:
76 return 0x01009090;
77 case 9 ... 11:
78 return 0x01000890;
79 case 12:
80 return 0x08009090;
81 case 13 ... 22:
82 return 0x01001090;
83 case 23 ... 36:
84 return 0x01008090;
85 case 37 ... 46:
86 return 0x08001090;
87 default:
88 return 0x08008090;
89 }
90}
91
92static const uint32_t axi_clkgen_lock_table[] = {
93 0x060603e8, 0x060603e8, 0x080803e8, 0x0b0b03e8,
94 0x0e0e03e8, 0x111103e8, 0x131303e8, 0x161603e8,
95 0x191903e8, 0x1c1c03e8, 0x1f1f0384, 0x1f1f0339,
96 0x1f1f02ee, 0x1f1f02bc, 0x1f1f028a, 0x1f1f0271,
97 0x1f1f023f, 0x1f1f0226, 0x1f1f020d, 0x1f1f01f4,
98 0x1f1f01db, 0x1f1f01c2, 0x1f1f01a9, 0x1f1f0190,
99 0x1f1f0190, 0x1f1f0177, 0x1f1f015e, 0x1f1f015e,
100 0x1f1f0145, 0x1f1f0145, 0x1f1f012c, 0x1f1f012c,
101 0x1f1f012c, 0x1f1f0113, 0x1f1f0113, 0x1f1f0113,
102};
103
104static uint32_t axi_clkgen_lookup_lock(unsigned int m)
105{
106 if (m < ARRAY_SIZE(axi_clkgen_lock_table))
107 return axi_clkgen_lock_table[m];
108 return 0x1f1f00fa;
109}
110
111static const struct axi_clkgen_limits axi_clkgen_zynqmp_default_limits = {
112 .fpfd_min = 10000,
113 .fpfd_max = 450000,
114 .fvco_min = 800000,
115 .fvco_max = 1600000,
116};
117
118static const struct axi_clkgen_limits axi_clkgen_zynq_default_limits = {
119 .fpfd_min = 10000,
120 .fpfd_max = 300000,
121 .fvco_min = 600000,
122 .fvco_max = 1200000,
123};
124
125static void axi_clkgen_calc_params(const struct axi_clkgen_limits *limits,
126 unsigned long fin, unsigned long fout,
127 unsigned int *best_d, unsigned int *best_m, unsigned int *best_dout)
128{
129 unsigned long d, d_min, d_max, _d_min, _d_max;
130 unsigned long m, m_min, m_max;
131 unsigned long f, dout, best_f, fvco;
132 unsigned long fract_shift = 0;
133 unsigned long fvco_min_fract, fvco_max_fract;
134
135 fin /= 1000;
136 fout /= 1000;
137
138 best_f = ULONG_MAX;
139 *best_d = 0;
140 *best_m = 0;
141 *best_dout = 0;
142
143 d_min = max_t(unsigned long, DIV_ROUND_UP(fin, limits->fpfd_max), 1);
144 d_max = min_t(unsigned long, fin / limits->fpfd_min, 80);
145
146again:
147 fvco_min_fract = limits->fvco_min << fract_shift;
148 fvco_max_fract = limits->fvco_max << fract_shift;
149
150 m_min = max_t(unsigned long, DIV_ROUND_UP(fvco_min_fract, fin) * d_min, 1);
151 m_max = min_t(unsigned long, fvco_max_fract * d_max / fin, 64 << fract_shift);
152
153 for (m = m_min; m <= m_max; m++) {
154 _d_min = max(d_min, DIV_ROUND_UP(fin * m, fvco_max_fract));
155 _d_max = min(d_max, fin * m / fvco_min_fract);
156
157 for (d = _d_min; d <= _d_max; d++) {
158 fvco = fin * m / d;
159
160 dout = DIV_ROUND_CLOSEST(fvco, fout);
161 dout = clamp_t(unsigned long, dout, 1, 128 << fract_shift);
162 f = fvco / dout;
163 if (abs(f - fout) < abs(best_f - fout)) {
164 best_f = f;
165 *best_d = d;
166 *best_m = m << (3 - fract_shift);
167 *best_dout = dout << (3 - fract_shift);
168 if (best_f == fout)
169 return;
170 }
171 }
172 }
173
174 /* Lets see if we find a better setting in fractional mode */
175 if (fract_shift == 0) {
176 fract_shift = 3;
177 goto again;
178 }
179}
180
181struct axi_clkgen_div_params {
182 unsigned int low;
183 unsigned int high;
184 unsigned int edge;
185 unsigned int nocount;
186 unsigned int frac_en;
187 unsigned int frac;
188 unsigned int frac_wf_f;
189 unsigned int frac_wf_r;
190 unsigned int frac_phase;
191};
192
193static void axi_clkgen_calc_clk_params(unsigned int divider,
194 unsigned int frac_divider, struct axi_clkgen_div_params *params)
195{
196
197 memset(params, 0x0, sizeof(*params));
198
199 if (divider == 1) {
200 params->nocount = 1;
201 return;
202 }
203
204 if (frac_divider == 0) {
205 params->high = divider / 2;
206 params->edge = divider % 2;
207 params->low = divider - params->high;
208 } else {
209 params->frac_en = 1;
210 params->frac = frac_divider;
211
212 params->high = divider / 2;
213 params->edge = divider % 2;
214 params->low = params->high;
215
216 if (params->edge == 0) {
217 params->high--;
218 params->frac_wf_r = 1;
219 }
220
221 if (params->edge == 0 || frac_divider == 1)
222 params->low--;
223 if (((params->edge == 0) ^ (frac_divider == 1)) ||
224 (divider == 2 && frac_divider == 1))
225 params->frac_wf_f = 1;
226
227 params->frac_phase = params->edge * 4 + frac_divider / 2;
228 }
229}
230
231static void axi_clkgen_write(struct axi_clkgen *axi_clkgen,
232 unsigned int reg, unsigned int val)
233{
234 writel(val, axi_clkgen->base + reg);
235}
236
237static void axi_clkgen_read(struct axi_clkgen *axi_clkgen,
238 unsigned int reg, unsigned int *val)
239{
240 *val = readl(axi_clkgen->base + reg);
241}
242
243static int axi_clkgen_wait_non_busy(struct axi_clkgen *axi_clkgen)
244{
245 unsigned int timeout = 10000;
246 unsigned int val;
247
248 do {
249 axi_clkgen_read(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_STATUS, &val);
250 } while ((val & AXI_CLKGEN_V2_DRP_STATUS_BUSY) && --timeout);
251
252 if (val & AXI_CLKGEN_V2_DRP_STATUS_BUSY)
253 return -EIO;
254
255 return val & 0xffff;
256}
257
258static int axi_clkgen_mmcm_read(struct axi_clkgen *axi_clkgen,
259 unsigned int reg, unsigned int *val)
260{
261 unsigned int reg_val;
262 int ret;
263
264 ret = axi_clkgen_wait_non_busy(axi_clkgen);
265 if (ret < 0)
266 return ret;
267
268 reg_val = AXI_CLKGEN_V2_DRP_CNTRL_SEL | AXI_CLKGEN_V2_DRP_CNTRL_READ;
269 reg_val |= (reg << 16);
270
271 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_CNTRL, reg_val);
272
273 ret = axi_clkgen_wait_non_busy(axi_clkgen);
274 if (ret < 0)
275 return ret;
276
277 *val = ret;
278
279 return 0;
280}
281
282static int axi_clkgen_mmcm_write(struct axi_clkgen *axi_clkgen,
283 unsigned int reg, unsigned int val, unsigned int mask)
284{
285 unsigned int reg_val = 0;
286 int ret;
287
288 ret = axi_clkgen_wait_non_busy(axi_clkgen);
289 if (ret < 0)
290 return ret;
291
292 if (mask != 0xffff) {
293 axi_clkgen_mmcm_read(axi_clkgen, reg, ®_val);
294 reg_val &= ~mask;
295 }
296
297 reg_val |= AXI_CLKGEN_V2_DRP_CNTRL_SEL | (reg << 16) | (val & mask);
298
299 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_CNTRL, reg_val);
300
301 return 0;
302}
303
304static void axi_clkgen_mmcm_enable(struct axi_clkgen *axi_clkgen,
305 bool enable)
306{
307 unsigned int val = AXI_CLKGEN_V2_RESET_ENABLE;
308
309 if (enable)
310 val |= AXI_CLKGEN_V2_RESET_MMCM_ENABLE;
311
312 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_RESET, val);
313}
314
315static struct axi_clkgen *clk_hw_to_axi_clkgen(struct clk_hw *clk_hw)
316{
317 return container_of(clk_hw, struct axi_clkgen, clk_hw);
318}
319
320static void axi_clkgen_set_div(struct axi_clkgen *axi_clkgen,
321 unsigned int reg1, unsigned int reg2, unsigned int reg3,
322 struct axi_clkgen_div_params *params)
323{
324 axi_clkgen_mmcm_write(axi_clkgen, reg1,
325 (params->high << 6) | params->low, 0xefff);
326 axi_clkgen_mmcm_write(axi_clkgen, reg2,
327 (params->frac << 12) | (params->frac_en << 11) |
328 (params->frac_wf_r << 10) | (params->edge << 7) |
329 (params->nocount << 6), 0x7fff);
330 if (reg3 != 0) {
331 axi_clkgen_mmcm_write(axi_clkgen, reg3,
332 (params->frac_phase << 11) | (params->frac_wf_f << 10), 0x3c00);
333 }
334}
335
336static int axi_clkgen_set_rate(struct clk_hw *clk_hw,
337 unsigned long rate, unsigned long parent_rate)
338{
339 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
340 const struct axi_clkgen_limits *limits = &axi_clkgen->limits;
341 unsigned int d, m, dout;
342 struct axi_clkgen_div_params params;
343 uint32_t power = 0;
344 uint32_t filter;
345 uint32_t lock;
346
347 if (parent_rate == 0 || rate == 0)
348 return -EINVAL;
349
350 axi_clkgen_calc_params(limits, parent_rate, rate, &d, &m, &dout);
351
352 if (d == 0 || dout == 0 || m == 0)
353 return -EINVAL;
354
355 if ((dout & 0x7) != 0 || (m & 0x7) != 0)
356 power |= 0x9800;
357
358 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_POWER, power, 0x9800);
359
360 filter = axi_clkgen_lookup_filter(m - 1);
361 lock = axi_clkgen_lookup_lock(m - 1);
362
363 axi_clkgen_calc_clk_params(dout >> 3, dout & 0x7, ¶ms);
364 axi_clkgen_set_div(axi_clkgen, MMCM_REG_CLKOUT0_1, MMCM_REG_CLKOUT0_2,
365 MMCM_REG_CLKOUT5_2, ¶ms);
366
367 axi_clkgen_calc_clk_params(d, 0, ¶ms);
368 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_DIV,
369 (params.edge << 13) | (params.nocount << 12) |
370 (params.high << 6) | params.low, 0x3fff);
371
372 axi_clkgen_calc_clk_params(m >> 3, m & 0x7, ¶ms);
373 axi_clkgen_set_div(axi_clkgen, MMCM_REG_CLK_FB1, MMCM_REG_CLK_FB2,
374 MMCM_REG_CLKOUT6_2, ¶ms);
375
376 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK1, lock & 0x3ff, 0x3ff);
377 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK2,
378 (((lock >> 16) & 0x1f) << 10) | 0x1, 0x7fff);
379 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK3,
380 (((lock >> 24) & 0x1f) << 10) | 0x3e9, 0x7fff);
381 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_FILTER1, filter >> 16, 0x9900);
382 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_FILTER2, filter, 0x9900);
383
384 return 0;
385}
386
387static long axi_clkgen_round_rate(struct clk_hw *hw, unsigned long rate,
388 unsigned long *parent_rate)
389{
390 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(hw);
391 const struct axi_clkgen_limits *limits = &axi_clkgen->limits;
392 unsigned int d, m, dout;
393 unsigned long long tmp;
394
395 axi_clkgen_calc_params(limits, *parent_rate, rate, &d, &m, &dout);
396
397 if (d == 0 || dout == 0 || m == 0)
398 return -EINVAL;
399
400 tmp = (unsigned long long)*parent_rate * m;
401 tmp = DIV_ROUND_CLOSEST_ULL(tmp, dout * d);
402
403 return min_t(unsigned long long, tmp, LONG_MAX);
404}
405
406static unsigned int axi_clkgen_get_div(struct axi_clkgen *axi_clkgen,
407 unsigned int reg1, unsigned int reg2)
408{
409 unsigned int val1, val2;
410 unsigned int div;
411
412 axi_clkgen_mmcm_read(axi_clkgen, reg2, &val2);
413 if (val2 & MMCM_CLKOUT_NOCOUNT)
414 return 8;
415
416 axi_clkgen_mmcm_read(axi_clkgen, reg1, &val1);
417
418 div = (val1 & 0x3f) + ((val1 >> 6) & 0x3f);
419 div <<= 3;
420
421 if (val2 & MMCM_CLK_DIV_DIVIDE) {
422 if ((val2 & BIT(7)) && (val2 & 0x7000) != 0x1000)
423 div += 8;
424 else
425 div += 16;
426
427 div += (val2 >> 12) & 0x7;
428 }
429
430 return div;
431}
432
433static unsigned long axi_clkgen_recalc_rate(struct clk_hw *clk_hw,
434 unsigned long parent_rate)
435{
436 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
437 unsigned int d, m, dout;
438 unsigned long long tmp;
439 unsigned int val;
440
441 dout = axi_clkgen_get_div(axi_clkgen, MMCM_REG_CLKOUT0_1,
442 MMCM_REG_CLKOUT0_2);
443 m = axi_clkgen_get_div(axi_clkgen, MMCM_REG_CLK_FB1,
444 MMCM_REG_CLK_FB2);
445
446 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_DIV, &val);
447 if (val & MMCM_CLK_DIV_NOCOUNT)
448 d = 1;
449 else
450 d = (val & 0x3f) + ((val >> 6) & 0x3f);
451
452 if (d == 0 || dout == 0)
453 return 0;
454
455 tmp = (unsigned long long)parent_rate * m;
456 tmp = DIV_ROUND_CLOSEST_ULL(tmp, dout * d);
457
458 return min_t(unsigned long long, tmp, ULONG_MAX);
459}
460
461static int axi_clkgen_enable(struct clk_hw *clk_hw)
462{
463 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
464
465 axi_clkgen_mmcm_enable(axi_clkgen, true);
466
467 return 0;
468}
469
470static void axi_clkgen_disable(struct clk_hw *clk_hw)
471{
472 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
473
474 axi_clkgen_mmcm_enable(axi_clkgen, false);
475}
476
477static int axi_clkgen_set_parent(struct clk_hw *clk_hw, u8 index)
478{
479 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
480
481 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_CLKSEL, index);
482
483 return 0;
484}
485
486static u8 axi_clkgen_get_parent(struct clk_hw *clk_hw)
487{
488 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
489 unsigned int parent;
490
491 axi_clkgen_read(axi_clkgen, AXI_CLKGEN_V2_REG_CLKSEL, &parent);
492
493 return parent;
494}
495
496static const struct clk_ops axi_clkgen_ops = {
497 .recalc_rate = axi_clkgen_recalc_rate,
498 .round_rate = axi_clkgen_round_rate,
499 .set_rate = axi_clkgen_set_rate,
500 .enable = axi_clkgen_enable,
501 .disable = axi_clkgen_disable,
502 .set_parent = axi_clkgen_set_parent,
503 .get_parent = axi_clkgen_get_parent,
504};
505
506static int axi_clkgen_probe(struct platform_device *pdev)
507{
508 const struct axi_clkgen_limits *dflt_limits;
509 struct axi_clkgen *axi_clkgen;
510 struct clk_init_data init;
511 const char *parent_names[2];
512 const char *clk_name;
513 unsigned int i;
514 int ret;
515
516 dflt_limits = device_get_match_data(&pdev->dev);
517 if (!dflt_limits)
518 return -ENODEV;
519
520 axi_clkgen = devm_kzalloc(&pdev->dev, sizeof(*axi_clkgen), GFP_KERNEL);
521 if (!axi_clkgen)
522 return -ENOMEM;
523
524 axi_clkgen->base = devm_platform_ioremap_resource(pdev, 0);
525 if (IS_ERR(axi_clkgen->base))
526 return PTR_ERR(axi_clkgen->base);
527
528 init.num_parents = of_clk_get_parent_count(pdev->dev.of_node);
529 if (init.num_parents < 1 || init.num_parents > 2)
530 return -EINVAL;
531
532 for (i = 0; i < init.num_parents; i++) {
533 parent_names[i] = of_clk_get_parent_name(pdev->dev.of_node, i);
534 if (!parent_names[i])
535 return -EINVAL;
536 }
537
538 memcpy(&axi_clkgen->limits, dflt_limits, sizeof(axi_clkgen->limits));
539
540 clk_name = pdev->dev.of_node->name;
541 of_property_read_string(pdev->dev.of_node, "clock-output-names",
542 &clk_name);
543
544 init.name = clk_name;
545 init.ops = &axi_clkgen_ops;
546 init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
547 init.parent_names = parent_names;
548
549 axi_clkgen_mmcm_enable(axi_clkgen, false);
550
551 axi_clkgen->clk_hw.init = &init;
552 ret = devm_clk_hw_register(&pdev->dev, &axi_clkgen->clk_hw);
553 if (ret)
554 return ret;
555
556 return of_clk_add_hw_provider(pdev->dev.of_node, of_clk_hw_simple_get,
557 &axi_clkgen->clk_hw);
558}
559
560static int axi_clkgen_remove(struct platform_device *pdev)
561{
562 of_clk_del_provider(pdev->dev.of_node);
563
564 return 0;
565}
566
567static const struct of_device_id axi_clkgen_ids[] = {
568 {
569 .compatible = "adi,zynqmp-axi-clkgen-2.00.a",
570 .data = &axi_clkgen_zynqmp_default_limits,
571 },
572 {
573 .compatible = "adi,axi-clkgen-2.00.a",
574 .data = &axi_clkgen_zynq_default_limits,
575 },
576 { }
577};
578MODULE_DEVICE_TABLE(of, axi_clkgen_ids);
579
580static struct platform_driver axi_clkgen_driver = {
581 .driver = {
582 .name = "adi-axi-clkgen",
583 .of_match_table = axi_clkgen_ids,
584 },
585 .probe = axi_clkgen_probe,
586 .remove = axi_clkgen_remove,
587};
588module_platform_driver(axi_clkgen_driver);
589
590MODULE_LICENSE("GPL v2");
591MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
592MODULE_DESCRIPTION("Driver for the Analog Devices' AXI clkgen pcore clock generator");