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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_CLKOUT0_1 0x08
31#define MMCM_REG_CLKOUT0_2 0x09
32#define MMCM_REG_CLK_FB1 0x14
33#define MMCM_REG_CLK_FB2 0x15
34#define MMCM_REG_CLK_DIV 0x16
35#define MMCM_REG_LOCK1 0x18
36#define MMCM_REG_LOCK2 0x19
37#define MMCM_REG_LOCK3 0x1a
38#define MMCM_REG_FILTER1 0x4e
39#define MMCM_REG_FILTER2 0x4f
40
41#define MMCM_CLKOUT_NOCOUNT BIT(6)
42
43#define MMCM_CLK_DIV_NOCOUNT BIT(12)
44
45struct axi_clkgen {
46 void __iomem *base;
47 struct clk_hw clk_hw;
48};
49
50static uint32_t axi_clkgen_lookup_filter(unsigned int m)
51{
52 switch (m) {
53 case 0:
54 return 0x01001990;
55 case 1:
56 return 0x01001190;
57 case 2:
58 return 0x01009890;
59 case 3:
60 return 0x01001890;
61 case 4:
62 return 0x01008890;
63 case 5 ... 8:
64 return 0x01009090;
65 case 9 ... 11:
66 return 0x01000890;
67 case 12:
68 return 0x08009090;
69 case 13 ... 22:
70 return 0x01001090;
71 case 23 ... 36:
72 return 0x01008090;
73 case 37 ... 46:
74 return 0x08001090;
75 default:
76 return 0x08008090;
77 }
78}
79
80static const uint32_t axi_clkgen_lock_table[] = {
81 0x060603e8, 0x060603e8, 0x080803e8, 0x0b0b03e8,
82 0x0e0e03e8, 0x111103e8, 0x131303e8, 0x161603e8,
83 0x191903e8, 0x1c1c03e8, 0x1f1f0384, 0x1f1f0339,
84 0x1f1f02ee, 0x1f1f02bc, 0x1f1f028a, 0x1f1f0271,
85 0x1f1f023f, 0x1f1f0226, 0x1f1f020d, 0x1f1f01f4,
86 0x1f1f01db, 0x1f1f01c2, 0x1f1f01a9, 0x1f1f0190,
87 0x1f1f0190, 0x1f1f0177, 0x1f1f015e, 0x1f1f015e,
88 0x1f1f0145, 0x1f1f0145, 0x1f1f012c, 0x1f1f012c,
89 0x1f1f012c, 0x1f1f0113, 0x1f1f0113, 0x1f1f0113,
90};
91
92static uint32_t axi_clkgen_lookup_lock(unsigned int m)
93{
94 if (m < ARRAY_SIZE(axi_clkgen_lock_table))
95 return axi_clkgen_lock_table[m];
96 return 0x1f1f00fa;
97}
98
99static const unsigned int fpfd_min = 10000;
100static const unsigned int fpfd_max = 300000;
101static const unsigned int fvco_min = 600000;
102static const unsigned int fvco_max = 1200000;
103
104static void axi_clkgen_calc_params(unsigned long fin, unsigned long fout,
105 unsigned int *best_d, unsigned int *best_m, unsigned int *best_dout)
106{
107 unsigned long d, d_min, d_max, _d_min, _d_max;
108 unsigned long m, m_min, m_max;
109 unsigned long f, dout, best_f, fvco;
110
111 fin /= 1000;
112 fout /= 1000;
113
114 best_f = ULONG_MAX;
115 *best_d = 0;
116 *best_m = 0;
117 *best_dout = 0;
118
119 d_min = max_t(unsigned long, DIV_ROUND_UP(fin, fpfd_max), 1);
120 d_max = min_t(unsigned long, fin / fpfd_min, 80);
121
122 m_min = max_t(unsigned long, DIV_ROUND_UP(fvco_min, fin) * d_min, 1);
123 m_max = min_t(unsigned long, fvco_max * d_max / fin, 64);
124
125 for (m = m_min; m <= m_max; m++) {
126 _d_min = max(d_min, DIV_ROUND_UP(fin * m, fvco_max));
127 _d_max = min(d_max, fin * m / fvco_min);
128
129 for (d = _d_min; d <= _d_max; d++) {
130 fvco = fin * m / d;
131
132 dout = DIV_ROUND_CLOSEST(fvco, fout);
133 dout = clamp_t(unsigned long, dout, 1, 128);
134 f = fvco / dout;
135 if (abs(f - fout) < abs(best_f - fout)) {
136 best_f = f;
137 *best_d = d;
138 *best_m = m;
139 *best_dout = dout;
140 if (best_f == fout)
141 return;
142 }
143 }
144 }
145}
146
147static void axi_clkgen_calc_clk_params(unsigned int divider, unsigned int *low,
148 unsigned int *high, unsigned int *edge, unsigned int *nocount)
149{
150 if (divider == 1)
151 *nocount = 1;
152 else
153 *nocount = 0;
154
155 *high = divider / 2;
156 *edge = divider % 2;
157 *low = divider - *high;
158}
159
160static void axi_clkgen_write(struct axi_clkgen *axi_clkgen,
161 unsigned int reg, unsigned int val)
162{
163 writel(val, axi_clkgen->base + reg);
164}
165
166static void axi_clkgen_read(struct axi_clkgen *axi_clkgen,
167 unsigned int reg, unsigned int *val)
168{
169 *val = readl(axi_clkgen->base + reg);
170}
171
172static int axi_clkgen_wait_non_busy(struct axi_clkgen *axi_clkgen)
173{
174 unsigned int timeout = 10000;
175 unsigned int val;
176
177 do {
178 axi_clkgen_read(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_STATUS, &val);
179 } while ((val & AXI_CLKGEN_V2_DRP_STATUS_BUSY) && --timeout);
180
181 if (val & AXI_CLKGEN_V2_DRP_STATUS_BUSY)
182 return -EIO;
183
184 return val & 0xffff;
185}
186
187static int axi_clkgen_mmcm_read(struct axi_clkgen *axi_clkgen,
188 unsigned int reg, unsigned int *val)
189{
190 unsigned int reg_val;
191 int ret;
192
193 ret = axi_clkgen_wait_non_busy(axi_clkgen);
194 if (ret < 0)
195 return ret;
196
197 reg_val = AXI_CLKGEN_V2_DRP_CNTRL_SEL | AXI_CLKGEN_V2_DRP_CNTRL_READ;
198 reg_val |= (reg << 16);
199
200 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_CNTRL, reg_val);
201
202 ret = axi_clkgen_wait_non_busy(axi_clkgen);
203 if (ret < 0)
204 return ret;
205
206 *val = ret;
207
208 return 0;
209}
210
211static int axi_clkgen_mmcm_write(struct axi_clkgen *axi_clkgen,
212 unsigned int reg, unsigned int val, unsigned int mask)
213{
214 unsigned int reg_val = 0;
215 int ret;
216
217 ret = axi_clkgen_wait_non_busy(axi_clkgen);
218 if (ret < 0)
219 return ret;
220
221 if (mask != 0xffff) {
222 axi_clkgen_mmcm_read(axi_clkgen, reg, ®_val);
223 reg_val &= ~mask;
224 }
225
226 reg_val |= AXI_CLKGEN_V2_DRP_CNTRL_SEL | (reg << 16) | (val & mask);
227
228 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_CNTRL, reg_val);
229
230 return 0;
231}
232
233static void axi_clkgen_mmcm_enable(struct axi_clkgen *axi_clkgen,
234 bool enable)
235{
236 unsigned int val = AXI_CLKGEN_V2_RESET_ENABLE;
237
238 if (enable)
239 val |= AXI_CLKGEN_V2_RESET_MMCM_ENABLE;
240
241 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_RESET, val);
242}
243
244static struct axi_clkgen *clk_hw_to_axi_clkgen(struct clk_hw *clk_hw)
245{
246 return container_of(clk_hw, struct axi_clkgen, clk_hw);
247}
248
249static int axi_clkgen_set_rate(struct clk_hw *clk_hw,
250 unsigned long rate, unsigned long parent_rate)
251{
252 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
253 unsigned int d, m, dout;
254 unsigned int nocount;
255 unsigned int high;
256 unsigned int edge;
257 unsigned int low;
258 uint32_t filter;
259 uint32_t lock;
260
261 if (parent_rate == 0 || rate == 0)
262 return -EINVAL;
263
264 axi_clkgen_calc_params(parent_rate, rate, &d, &m, &dout);
265
266 if (d == 0 || dout == 0 || m == 0)
267 return -EINVAL;
268
269 filter = axi_clkgen_lookup_filter(m - 1);
270 lock = axi_clkgen_lookup_lock(m - 1);
271
272 axi_clkgen_calc_clk_params(dout, &low, &high, &edge, &nocount);
273 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLKOUT0_1,
274 (high << 6) | low, 0xefff);
275 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLKOUT0_2,
276 (edge << 7) | (nocount << 6), 0x03ff);
277
278 axi_clkgen_calc_clk_params(d, &low, &high, &edge, &nocount);
279 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_DIV,
280 (edge << 13) | (nocount << 12) | (high << 6) | low, 0x3fff);
281
282 axi_clkgen_calc_clk_params(m, &low, &high, &edge, &nocount);
283 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_FB1,
284 (high << 6) | low, 0xefff);
285 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_FB2,
286 (edge << 7) | (nocount << 6), 0x03ff);
287
288 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK1, lock & 0x3ff, 0x3ff);
289 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK2,
290 (((lock >> 16) & 0x1f) << 10) | 0x1, 0x7fff);
291 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK3,
292 (((lock >> 24) & 0x1f) << 10) | 0x3e9, 0x7fff);
293 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_FILTER1, filter >> 16, 0x9900);
294 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_FILTER2, filter, 0x9900);
295
296 return 0;
297}
298
299static long axi_clkgen_round_rate(struct clk_hw *hw, unsigned long rate,
300 unsigned long *parent_rate)
301{
302 unsigned int d, m, dout;
303 unsigned long long tmp;
304
305 axi_clkgen_calc_params(*parent_rate, rate, &d, &m, &dout);
306
307 if (d == 0 || dout == 0 || m == 0)
308 return -EINVAL;
309
310 tmp = (unsigned long long)*parent_rate * m;
311 tmp = DIV_ROUND_CLOSEST_ULL(tmp, dout * d);
312
313 return min_t(unsigned long long, tmp, LONG_MAX);
314}
315
316static unsigned long axi_clkgen_recalc_rate(struct clk_hw *clk_hw,
317 unsigned long parent_rate)
318{
319 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
320 unsigned int d, m, dout;
321 unsigned int reg;
322 unsigned long long tmp;
323
324 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_2, ®);
325 if (reg & MMCM_CLKOUT_NOCOUNT) {
326 dout = 1;
327 } else {
328 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_1, ®);
329 dout = (reg & 0x3f) + ((reg >> 6) & 0x3f);
330 }
331
332 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_DIV, ®);
333 if (reg & MMCM_CLK_DIV_NOCOUNT)
334 d = 1;
335 else
336 d = (reg & 0x3f) + ((reg >> 6) & 0x3f);
337
338 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB2, ®);
339 if (reg & MMCM_CLKOUT_NOCOUNT) {
340 m = 1;
341 } else {
342 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB1, ®);
343 m = (reg & 0x3f) + ((reg >> 6) & 0x3f);
344 }
345
346 if (d == 0 || dout == 0)
347 return 0;
348
349 tmp = (unsigned long long)parent_rate * m;
350 tmp = DIV_ROUND_CLOSEST_ULL(tmp, dout * d);
351
352 return min_t(unsigned long long, tmp, ULONG_MAX);
353}
354
355static int axi_clkgen_enable(struct clk_hw *clk_hw)
356{
357 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
358
359 axi_clkgen_mmcm_enable(axi_clkgen, true);
360
361 return 0;
362}
363
364static void axi_clkgen_disable(struct clk_hw *clk_hw)
365{
366 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
367
368 axi_clkgen_mmcm_enable(axi_clkgen, false);
369}
370
371static int axi_clkgen_set_parent(struct clk_hw *clk_hw, u8 index)
372{
373 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
374
375 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_CLKSEL, index);
376
377 return 0;
378}
379
380static u8 axi_clkgen_get_parent(struct clk_hw *clk_hw)
381{
382 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw);
383 unsigned int parent;
384
385 axi_clkgen_read(axi_clkgen, AXI_CLKGEN_V2_REG_CLKSEL, &parent);
386
387 return parent;
388}
389
390static const struct clk_ops axi_clkgen_ops = {
391 .recalc_rate = axi_clkgen_recalc_rate,
392 .round_rate = axi_clkgen_round_rate,
393 .set_rate = axi_clkgen_set_rate,
394 .enable = axi_clkgen_enable,
395 .disable = axi_clkgen_disable,
396 .set_parent = axi_clkgen_set_parent,
397 .get_parent = axi_clkgen_get_parent,
398};
399
400static const struct of_device_id axi_clkgen_ids[] = {
401 {
402 .compatible = "adi,axi-clkgen-2.00.a",
403 },
404 { },
405};
406MODULE_DEVICE_TABLE(of, axi_clkgen_ids);
407
408static int axi_clkgen_probe(struct platform_device *pdev)
409{
410 const struct of_device_id *id;
411 struct axi_clkgen *axi_clkgen;
412 struct clk_init_data init;
413 const char *parent_names[2];
414 const char *clk_name;
415 struct resource *mem;
416 unsigned int i;
417 int ret;
418
419 if (!pdev->dev.of_node)
420 return -ENODEV;
421
422 id = of_match_node(axi_clkgen_ids, pdev->dev.of_node);
423 if (!id)
424 return -ENODEV;
425
426 axi_clkgen = devm_kzalloc(&pdev->dev, sizeof(*axi_clkgen), GFP_KERNEL);
427 if (!axi_clkgen)
428 return -ENOMEM;
429
430 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
431 axi_clkgen->base = devm_ioremap_resource(&pdev->dev, mem);
432 if (IS_ERR(axi_clkgen->base))
433 return PTR_ERR(axi_clkgen->base);
434
435 init.num_parents = of_clk_get_parent_count(pdev->dev.of_node);
436 if (init.num_parents < 1 || init.num_parents > 2)
437 return -EINVAL;
438
439 for (i = 0; i < init.num_parents; i++) {
440 parent_names[i] = of_clk_get_parent_name(pdev->dev.of_node, i);
441 if (!parent_names[i])
442 return -EINVAL;
443 }
444
445 clk_name = pdev->dev.of_node->name;
446 of_property_read_string(pdev->dev.of_node, "clock-output-names",
447 &clk_name);
448
449 init.name = clk_name;
450 init.ops = &axi_clkgen_ops;
451 init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
452 init.parent_names = parent_names;
453
454 axi_clkgen_mmcm_enable(axi_clkgen, false);
455
456 axi_clkgen->clk_hw.init = &init;
457 ret = devm_clk_hw_register(&pdev->dev, &axi_clkgen->clk_hw);
458 if (ret)
459 return ret;
460
461 return of_clk_add_hw_provider(pdev->dev.of_node, of_clk_hw_simple_get,
462 &axi_clkgen->clk_hw);
463}
464
465static int axi_clkgen_remove(struct platform_device *pdev)
466{
467 of_clk_del_provider(pdev->dev.of_node);
468
469 return 0;
470}
471
472static struct platform_driver axi_clkgen_driver = {
473 .driver = {
474 .name = "adi-axi-clkgen",
475 .of_match_table = axi_clkgen_ids,
476 },
477 .probe = axi_clkgen_probe,
478 .remove = axi_clkgen_remove,
479};
480module_platform_driver(axi_clkgen_driver);
481
482MODULE_LICENSE("GPL v2");
483MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
484MODULE_DESCRIPTION("Driver for the Analog Devices' AXI clkgen pcore clock generator");