xref: /linux/drivers/clk/qcom/clk-rcg2.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /*
2  * Copyright (c) 2013, The Linux Foundation. All rights reserved.
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/bitops.h>
16 #include <linux/err.h>
17 #include <linux/bug.h>
18 #include <linux/export.h>
19 #include <linux/clk-provider.h>
20 #include <linux/delay.h>
21 #include <linux/regmap.h>
22 #include <linux/math64.h>
23 
24 #include <asm/div64.h>
25 
26 #include "clk-rcg.h"
27 #include "common.h"
28 
29 #define CMD_REG			0x0
30 #define CMD_UPDATE		BIT(0)
31 #define CMD_ROOT_EN		BIT(1)
32 #define CMD_DIRTY_CFG		BIT(4)
33 #define CMD_DIRTY_N		BIT(5)
34 #define CMD_DIRTY_M		BIT(6)
35 #define CMD_DIRTY_D		BIT(7)
36 #define CMD_ROOT_OFF		BIT(31)
37 
38 #define CFG_REG			0x4
39 #define CFG_SRC_DIV_SHIFT	0
40 #define CFG_SRC_SEL_SHIFT	8
41 #define CFG_SRC_SEL_MASK	(0x7 << CFG_SRC_SEL_SHIFT)
42 #define CFG_MODE_SHIFT		12
43 #define CFG_MODE_MASK		(0x3 << CFG_MODE_SHIFT)
44 #define CFG_MODE_DUAL_EDGE	(0x2 << CFG_MODE_SHIFT)
45 
46 #define M_REG			0x8
47 #define N_REG			0xc
48 #define D_REG			0x10
49 
50 static int clk_rcg2_is_enabled(struct clk_hw *hw)
51 {
52 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
53 	u32 cmd;
54 	int ret;
55 
56 	ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG, &cmd);
57 	if (ret)
58 		return ret;
59 
60 	return (cmd & CMD_ROOT_OFF) == 0;
61 }
62 
63 static u8 clk_rcg2_get_parent(struct clk_hw *hw)
64 {
65 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
66 	int num_parents = __clk_get_num_parents(hw->clk);
67 	u32 cfg;
68 	int i, ret;
69 
70 	ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, &cfg);
71 	if (ret)
72 		return ret;
73 
74 	cfg &= CFG_SRC_SEL_MASK;
75 	cfg >>= CFG_SRC_SEL_SHIFT;
76 
77 	for (i = 0; i < num_parents; i++)
78 		if (cfg == rcg->parent_map[i])
79 			return i;
80 
81 	return -EINVAL;
82 }
83 
84 static int update_config(struct clk_rcg2 *rcg)
85 {
86 	int count, ret;
87 	u32 cmd;
88 	struct clk_hw *hw = &rcg->clkr.hw;
89 	const char *name = __clk_get_name(hw->clk);
90 
91 	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG,
92 				 CMD_UPDATE, CMD_UPDATE);
93 	if (ret)
94 		return ret;
95 
96 	/* Wait for update to take effect */
97 	for (count = 500; count > 0; count--) {
98 		ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG, &cmd);
99 		if (ret)
100 			return ret;
101 		if (!(cmd & CMD_UPDATE))
102 			return 0;
103 		udelay(1);
104 	}
105 
106 	WARN(1, "%s: rcg didn't update its configuration.", name);
107 	return 0;
108 }
109 
110 static int clk_rcg2_set_parent(struct clk_hw *hw, u8 index)
111 {
112 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
113 	int ret;
114 
115 	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
116 				 CFG_SRC_SEL_MASK,
117 				 rcg->parent_map[index] << CFG_SRC_SEL_SHIFT);
118 	if (ret)
119 		return ret;
120 
121 	return update_config(rcg);
122 }
123 
124 /*
125  * Calculate m/n:d rate
126  *
127  *          parent_rate     m
128  *   rate = ----------- x  ---
129  *            hid_div       n
130  */
131 static unsigned long
132 calc_rate(unsigned long rate, u32 m, u32 n, u32 mode, u32 hid_div)
133 {
134 	if (hid_div) {
135 		rate *= 2;
136 		rate /= hid_div + 1;
137 	}
138 
139 	if (mode) {
140 		u64 tmp = rate;
141 		tmp *= m;
142 		do_div(tmp, n);
143 		rate = tmp;
144 	}
145 
146 	return rate;
147 }
148 
149 static unsigned long
150 clk_rcg2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
151 {
152 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
153 	u32 cfg, hid_div, m = 0, n = 0, mode = 0, mask;
154 
155 	regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, &cfg);
156 
157 	if (rcg->mnd_width) {
158 		mask = BIT(rcg->mnd_width) - 1;
159 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + M_REG, &m);
160 		m &= mask;
161 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + N_REG, &n);
162 		n =  ~n;
163 		n &= mask;
164 		n += m;
165 		mode = cfg & CFG_MODE_MASK;
166 		mode >>= CFG_MODE_SHIFT;
167 	}
168 
169 	mask = BIT(rcg->hid_width) - 1;
170 	hid_div = cfg >> CFG_SRC_DIV_SHIFT;
171 	hid_div &= mask;
172 
173 	return calc_rate(parent_rate, m, n, mode, hid_div);
174 }
175 
176 static long _freq_tbl_determine_rate(struct clk_hw *hw,
177 		const struct freq_tbl *f, unsigned long rate,
178 		unsigned long *p_rate, struct clk_hw **p_hw)
179 {
180 	unsigned long clk_flags;
181 	struct clk *p;
182 
183 	f = qcom_find_freq(f, rate);
184 	if (!f)
185 		return -EINVAL;
186 
187 	clk_flags = __clk_get_flags(hw->clk);
188 	p = clk_get_parent_by_index(hw->clk, f->src);
189 	if (clk_flags & CLK_SET_RATE_PARENT) {
190 		if (f->pre_div) {
191 			rate /= 2;
192 			rate *= f->pre_div + 1;
193 		}
194 
195 		if (f->n) {
196 			u64 tmp = rate;
197 			tmp = tmp * f->n;
198 			do_div(tmp, f->m);
199 			rate = tmp;
200 		}
201 	} else {
202 		rate =  __clk_get_rate(p);
203 	}
204 	*p_hw = __clk_get_hw(p);
205 	*p_rate = rate;
206 
207 	return f->freq;
208 }
209 
210 static long clk_rcg2_determine_rate(struct clk_hw *hw, unsigned long rate,
211 		unsigned long min_rate, unsigned long max_rate,
212 		unsigned long *p_rate, struct clk_hw **p)
213 {
214 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
215 
216 	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, rate, p_rate, p);
217 }
218 
219 static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
220 {
221 	u32 cfg, mask;
222 	int ret;
223 
224 	if (rcg->mnd_width && f->n) {
225 		mask = BIT(rcg->mnd_width) - 1;
226 		ret = regmap_update_bits(rcg->clkr.regmap,
227 				rcg->cmd_rcgr + M_REG, mask, f->m);
228 		if (ret)
229 			return ret;
230 
231 		ret = regmap_update_bits(rcg->clkr.regmap,
232 				rcg->cmd_rcgr + N_REG, mask, ~(f->n - f->m));
233 		if (ret)
234 			return ret;
235 
236 		ret = regmap_update_bits(rcg->clkr.regmap,
237 				rcg->cmd_rcgr + D_REG, mask, ~f->n);
238 		if (ret)
239 			return ret;
240 	}
241 
242 	mask = BIT(rcg->hid_width) - 1;
243 	mask |= CFG_SRC_SEL_MASK | CFG_MODE_MASK;
244 	cfg = f->pre_div << CFG_SRC_DIV_SHIFT;
245 	cfg |= rcg->parent_map[f->src] << CFG_SRC_SEL_SHIFT;
246 	if (rcg->mnd_width && f->n)
247 		cfg |= CFG_MODE_DUAL_EDGE;
248 	ret = regmap_update_bits(rcg->clkr.regmap,
249 			rcg->cmd_rcgr + CFG_REG, mask, cfg);
250 	if (ret)
251 		return ret;
252 
253 	return update_config(rcg);
254 }
255 
256 static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
257 {
258 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
259 	const struct freq_tbl *f;
260 
261 	f = qcom_find_freq(rcg->freq_tbl, rate);
262 	if (!f)
263 		return -EINVAL;
264 
265 	return clk_rcg2_configure(rcg, f);
266 }
267 
268 static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
269 			    unsigned long parent_rate)
270 {
271 	return __clk_rcg2_set_rate(hw, rate);
272 }
273 
274 static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
275 		unsigned long rate, unsigned long parent_rate, u8 index)
276 {
277 	return __clk_rcg2_set_rate(hw, rate);
278 }
279 
280 const struct clk_ops clk_rcg2_ops = {
281 	.is_enabled = clk_rcg2_is_enabled,
282 	.get_parent = clk_rcg2_get_parent,
283 	.set_parent = clk_rcg2_set_parent,
284 	.recalc_rate = clk_rcg2_recalc_rate,
285 	.determine_rate = clk_rcg2_determine_rate,
286 	.set_rate = clk_rcg2_set_rate,
287 	.set_rate_and_parent = clk_rcg2_set_rate_and_parent,
288 };
289 EXPORT_SYMBOL_GPL(clk_rcg2_ops);
290 
291 struct frac_entry {
292 	int num;
293 	int den;
294 };
295 
296 static const struct frac_entry frac_table_675m[] = {	/* link rate of 270M */
297 	{ 52, 295 },	/* 119 M */
298 	{ 11, 57 },	/* 130.25 M */
299 	{ 63, 307 },	/* 138.50 M */
300 	{ 11, 50 },	/* 148.50 M */
301 	{ 47, 206 },	/* 154 M */
302 	{ 31, 100 },	/* 205.25 M */
303 	{ 107, 269 },	/* 268.50 M */
304 	{ },
305 };
306 
307 static struct frac_entry frac_table_810m[] = { /* Link rate of 162M */
308 	{ 31, 211 },	/* 119 M */
309 	{ 32, 199 },	/* 130.25 M */
310 	{ 63, 307 },	/* 138.50 M */
311 	{ 11, 60 },	/* 148.50 M */
312 	{ 50, 263 },	/* 154 M */
313 	{ 31, 120 },	/* 205.25 M */
314 	{ 119, 359 },	/* 268.50 M */
315 	{ },
316 };
317 
318 static int clk_edp_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
319 			      unsigned long parent_rate)
320 {
321 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
322 	struct freq_tbl f = *rcg->freq_tbl;
323 	const struct frac_entry *frac;
324 	int delta = 100000;
325 	s64 src_rate = parent_rate;
326 	s64 request;
327 	u32 mask = BIT(rcg->hid_width) - 1;
328 	u32 hid_div;
329 
330 	if (src_rate == 810000000)
331 		frac = frac_table_810m;
332 	else
333 		frac = frac_table_675m;
334 
335 	for (; frac->num; frac++) {
336 		request = rate;
337 		request *= frac->den;
338 		request = div_s64(request, frac->num);
339 		if ((src_rate < (request - delta)) ||
340 		    (src_rate > (request + delta)))
341 			continue;
342 
343 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
344 				&hid_div);
345 		f.pre_div = hid_div;
346 		f.pre_div >>= CFG_SRC_DIV_SHIFT;
347 		f.pre_div &= mask;
348 		f.m = frac->num;
349 		f.n = frac->den;
350 
351 		return clk_rcg2_configure(rcg, &f);
352 	}
353 
354 	return -EINVAL;
355 }
356 
357 static int clk_edp_pixel_set_rate_and_parent(struct clk_hw *hw,
358 		unsigned long rate, unsigned long parent_rate, u8 index)
359 {
360 	/* Parent index is set statically in frequency table */
361 	return clk_edp_pixel_set_rate(hw, rate, parent_rate);
362 }
363 
364 static long clk_edp_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
365 				 unsigned long min_rate,
366 				 unsigned long max_rate,
367 				 unsigned long *p_rate, struct clk_hw **p)
368 {
369 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
370 	const struct freq_tbl *f = rcg->freq_tbl;
371 	const struct frac_entry *frac;
372 	int delta = 100000;
373 	s64 src_rate = *p_rate;
374 	s64 request;
375 	u32 mask = BIT(rcg->hid_width) - 1;
376 	u32 hid_div;
377 
378 	/* Force the correct parent */
379 	*p = __clk_get_hw(clk_get_parent_by_index(hw->clk, f->src));
380 
381 	if (src_rate == 810000000)
382 		frac = frac_table_810m;
383 	else
384 		frac = frac_table_675m;
385 
386 	for (; frac->num; frac++) {
387 		request = rate;
388 		request *= frac->den;
389 		request = div_s64(request, frac->num);
390 		if ((src_rate < (request - delta)) ||
391 		    (src_rate > (request + delta)))
392 			continue;
393 
394 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
395 				&hid_div);
396 		hid_div >>= CFG_SRC_DIV_SHIFT;
397 		hid_div &= mask;
398 
399 		return calc_rate(src_rate, frac->num, frac->den, !!frac->den,
400 				 hid_div);
401 	}
402 
403 	return -EINVAL;
404 }
405 
406 const struct clk_ops clk_edp_pixel_ops = {
407 	.is_enabled = clk_rcg2_is_enabled,
408 	.get_parent = clk_rcg2_get_parent,
409 	.set_parent = clk_rcg2_set_parent,
410 	.recalc_rate = clk_rcg2_recalc_rate,
411 	.set_rate = clk_edp_pixel_set_rate,
412 	.set_rate_and_parent = clk_edp_pixel_set_rate_and_parent,
413 	.determine_rate = clk_edp_pixel_determine_rate,
414 };
415 EXPORT_SYMBOL_GPL(clk_edp_pixel_ops);
416 
417 static long clk_byte_determine_rate(struct clk_hw *hw, unsigned long rate,
418 			 unsigned long min_rate, unsigned long max_rate,
419 			 unsigned long *p_rate, struct clk_hw **p_hw)
420 {
421 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
422 	const struct freq_tbl *f = rcg->freq_tbl;
423 	unsigned long parent_rate, div;
424 	u32 mask = BIT(rcg->hid_width) - 1;
425 	struct clk *p;
426 
427 	if (rate == 0)
428 		return -EINVAL;
429 
430 	p = clk_get_parent_by_index(hw->clk, f->src);
431 	*p_hw = __clk_get_hw(p);
432 	*p_rate = parent_rate = __clk_round_rate(p, rate);
433 
434 	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
435 	div = min_t(u32, div, mask);
436 
437 	return calc_rate(parent_rate, 0, 0, 0, div);
438 }
439 
440 static int clk_byte_set_rate(struct clk_hw *hw, unsigned long rate,
441 			 unsigned long parent_rate)
442 {
443 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
444 	struct freq_tbl f = *rcg->freq_tbl;
445 	unsigned long div;
446 	u32 mask = BIT(rcg->hid_width) - 1;
447 
448 	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
449 	div = min_t(u32, div, mask);
450 
451 	f.pre_div = div;
452 
453 	return clk_rcg2_configure(rcg, &f);
454 }
455 
456 static int clk_byte_set_rate_and_parent(struct clk_hw *hw,
457 		unsigned long rate, unsigned long parent_rate, u8 index)
458 {
459 	/* Parent index is set statically in frequency table */
460 	return clk_byte_set_rate(hw, rate, parent_rate);
461 }
462 
463 const struct clk_ops clk_byte_ops = {
464 	.is_enabled = clk_rcg2_is_enabled,
465 	.get_parent = clk_rcg2_get_parent,
466 	.set_parent = clk_rcg2_set_parent,
467 	.recalc_rate = clk_rcg2_recalc_rate,
468 	.set_rate = clk_byte_set_rate,
469 	.set_rate_and_parent = clk_byte_set_rate_and_parent,
470 	.determine_rate = clk_byte_determine_rate,
471 };
472 EXPORT_SYMBOL_GPL(clk_byte_ops);
473 
474 static const struct frac_entry frac_table_pixel[] = {
475 	{ 3, 8 },
476 	{ 2, 9 },
477 	{ 4, 9 },
478 	{ 1, 1 },
479 	{ }
480 };
481 
482 static long clk_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
483 				 unsigned long min_rate,
484 				 unsigned long max_rate,
485 				 unsigned long *p_rate, struct clk_hw **p)
486 {
487 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
488 	unsigned long request, src_rate;
489 	int delta = 100000;
490 	const struct freq_tbl *f = rcg->freq_tbl;
491 	const struct frac_entry *frac = frac_table_pixel;
492 	struct clk *parent = clk_get_parent_by_index(hw->clk, f->src);
493 
494 	*p = __clk_get_hw(parent);
495 
496 	for (; frac->num; frac++) {
497 		request = (rate * frac->den) / frac->num;
498 
499 		src_rate = __clk_round_rate(parent, request);
500 		if ((src_rate < (request - delta)) ||
501 			(src_rate > (request + delta)))
502 			continue;
503 
504 		*p_rate = src_rate;
505 		return (src_rate * frac->num) / frac->den;
506 	}
507 
508 	return -EINVAL;
509 }
510 
511 static int clk_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
512 		unsigned long parent_rate)
513 {
514 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
515 	struct freq_tbl f = *rcg->freq_tbl;
516 	const struct frac_entry *frac = frac_table_pixel;
517 	unsigned long request, src_rate;
518 	int delta = 100000;
519 	u32 mask = BIT(rcg->hid_width) - 1;
520 	u32 hid_div;
521 	struct clk *parent = clk_get_parent_by_index(hw->clk, f.src);
522 
523 	for (; frac->num; frac++) {
524 		request = (rate * frac->den) / frac->num;
525 
526 		src_rate = __clk_round_rate(parent, request);
527 		if ((src_rate < (request - delta)) ||
528 			(src_rate > (request + delta)))
529 			continue;
530 
531 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
532 				&hid_div);
533 		f.pre_div = hid_div;
534 		f.pre_div >>= CFG_SRC_DIV_SHIFT;
535 		f.pre_div &= mask;
536 		f.m = frac->num;
537 		f.n = frac->den;
538 
539 		return clk_rcg2_configure(rcg, &f);
540 	}
541 	return -EINVAL;
542 }
543 
544 static int clk_pixel_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
545 		unsigned long parent_rate, u8 index)
546 {
547 	/* Parent index is set statically in frequency table */
548 	return clk_pixel_set_rate(hw, rate, parent_rate);
549 }
550 
551 const struct clk_ops clk_pixel_ops = {
552 	.is_enabled = clk_rcg2_is_enabled,
553 	.get_parent = clk_rcg2_get_parent,
554 	.set_parent = clk_rcg2_set_parent,
555 	.recalc_rate = clk_rcg2_recalc_rate,
556 	.set_rate = clk_pixel_set_rate,
557 	.set_rate_and_parent = clk_pixel_set_rate_and_parent,
558 	.determine_rate = clk_pixel_determine_rate,
559 };
560 EXPORT_SYMBOL_GPL(clk_pixel_ops);
561