xref: /linux/drivers/clk/qcom/clk-rcg2.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 
28 #define CMD_REG			0x0
29 #define CMD_UPDATE		BIT(0)
30 #define CMD_ROOT_EN		BIT(1)
31 #define CMD_DIRTY_CFG		BIT(4)
32 #define CMD_DIRTY_N		BIT(5)
33 #define CMD_DIRTY_M		BIT(6)
34 #define CMD_DIRTY_D		BIT(7)
35 #define CMD_ROOT_OFF		BIT(31)
36 
37 #define CFG_REG			0x4
38 #define CFG_SRC_DIV_SHIFT	0
39 #define CFG_SRC_SEL_SHIFT	8
40 #define CFG_SRC_SEL_MASK	(0x7 << CFG_SRC_SEL_SHIFT)
41 #define CFG_MODE_SHIFT		12
42 #define CFG_MODE_MASK		(0x3 << CFG_MODE_SHIFT)
43 #define CFG_MODE_DUAL_EDGE	(0x2 << CFG_MODE_SHIFT)
44 
45 #define M_REG			0x8
46 #define N_REG			0xc
47 #define D_REG			0x10
48 
49 static int clk_rcg2_is_enabled(struct clk_hw *hw)
50 {
51 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
52 	u32 cmd;
53 	int ret;
54 
55 	ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG, &cmd);
56 	if (ret)
57 		return ret;
58 
59 	return (cmd & CMD_ROOT_OFF) == 0;
60 }
61 
62 static u8 clk_rcg2_get_parent(struct clk_hw *hw)
63 {
64 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
65 	int num_parents = __clk_get_num_parents(hw->clk);
66 	u32 cfg;
67 	int i, ret;
68 
69 	ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, &cfg);
70 	if (ret)
71 		return ret;
72 
73 	cfg &= CFG_SRC_SEL_MASK;
74 	cfg >>= CFG_SRC_SEL_SHIFT;
75 
76 	for (i = 0; i < num_parents; i++)
77 		if (cfg == rcg->parent_map[i])
78 			return i;
79 
80 	return -EINVAL;
81 }
82 
83 static int update_config(struct clk_rcg2 *rcg)
84 {
85 	int count, ret;
86 	u32 cmd;
87 	struct clk_hw *hw = &rcg->clkr.hw;
88 	const char *name = __clk_get_name(hw->clk);
89 
90 	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG,
91 				 CMD_UPDATE, CMD_UPDATE);
92 	if (ret)
93 		return ret;
94 
95 	/* Wait for update to take effect */
96 	for (count = 500; count > 0; count--) {
97 		ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG, &cmd);
98 		if (ret)
99 			return ret;
100 		if (!(cmd & CMD_UPDATE))
101 			return 0;
102 		udelay(1);
103 	}
104 
105 	WARN(1, "%s: rcg didn't update its configuration.", name);
106 	return 0;
107 }
108 
109 static int clk_rcg2_set_parent(struct clk_hw *hw, u8 index)
110 {
111 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
112 	int ret;
113 
114 	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
115 				 CFG_SRC_SEL_MASK,
116 				 rcg->parent_map[index] << CFG_SRC_SEL_SHIFT);
117 	if (ret)
118 		return ret;
119 
120 	return update_config(rcg);
121 }
122 
123 /*
124  * Calculate m/n:d rate
125  *
126  *          parent_rate     m
127  *   rate = ----------- x  ---
128  *            hid_div       n
129  */
130 static unsigned long
131 calc_rate(unsigned long rate, u32 m, u32 n, u32 mode, u32 hid_div)
132 {
133 	if (hid_div) {
134 		rate *= 2;
135 		rate /= hid_div + 1;
136 	}
137 
138 	if (mode) {
139 		u64 tmp = rate;
140 		tmp *= m;
141 		do_div(tmp, n);
142 		rate = tmp;
143 	}
144 
145 	return rate;
146 }
147 
148 static unsigned long
149 clk_rcg2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
150 {
151 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
152 	u32 cfg, hid_div, m = 0, n = 0, mode = 0, mask;
153 
154 	regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, &cfg);
155 
156 	if (rcg->mnd_width) {
157 		mask = BIT(rcg->mnd_width) - 1;
158 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + M_REG, &m);
159 		m &= mask;
160 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + N_REG, &n);
161 		n =  ~n;
162 		n &= mask;
163 		n += m;
164 		mode = cfg & CFG_MODE_MASK;
165 		mode >>= CFG_MODE_SHIFT;
166 	}
167 
168 	mask = BIT(rcg->hid_width) - 1;
169 	hid_div = cfg >> CFG_SRC_DIV_SHIFT;
170 	hid_div &= mask;
171 
172 	return calc_rate(parent_rate, m, n, mode, hid_div);
173 }
174 
175 static const
176 struct freq_tbl *find_freq(const struct freq_tbl *f, unsigned long rate)
177 {
178 	if (!f)
179 		return NULL;
180 
181 	for (; f->freq; f++)
182 		if (rate <= f->freq)
183 			return f;
184 
185 	/* Default to our fastest rate */
186 	return f - 1;
187 }
188 
189 static long _freq_tbl_determine_rate(struct clk_hw *hw,
190 		const struct freq_tbl *f, unsigned long rate,
191 		unsigned long *p_rate, struct clk **p)
192 {
193 	unsigned long clk_flags;
194 
195 	f = find_freq(f, rate);
196 	if (!f)
197 		return -EINVAL;
198 
199 	clk_flags = __clk_get_flags(hw->clk);
200 	*p = clk_get_parent_by_index(hw->clk, f->src);
201 	if (clk_flags & CLK_SET_RATE_PARENT) {
202 		if (f->pre_div) {
203 			rate /= 2;
204 			rate *= f->pre_div + 1;
205 		}
206 
207 		if (f->n) {
208 			u64 tmp = rate;
209 			tmp = tmp * f->n;
210 			do_div(tmp, f->m);
211 			rate = tmp;
212 		}
213 	} else {
214 		rate =  __clk_get_rate(*p);
215 	}
216 	*p_rate = rate;
217 
218 	return f->freq;
219 }
220 
221 static long clk_rcg2_determine_rate(struct clk_hw *hw, unsigned long rate,
222 		unsigned long *p_rate, struct clk **p)
223 {
224 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
225 
226 	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, rate, p_rate, p);
227 }
228 
229 static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
230 {
231 	u32 cfg, mask;
232 	int ret;
233 
234 	if (rcg->mnd_width && f->n) {
235 		mask = BIT(rcg->mnd_width) - 1;
236 		ret = regmap_update_bits(rcg->clkr.regmap,
237 				rcg->cmd_rcgr + M_REG, mask, f->m);
238 		if (ret)
239 			return ret;
240 
241 		ret = regmap_update_bits(rcg->clkr.regmap,
242 				rcg->cmd_rcgr + N_REG, mask, ~(f->n - f->m));
243 		if (ret)
244 			return ret;
245 
246 		ret = regmap_update_bits(rcg->clkr.regmap,
247 				rcg->cmd_rcgr + D_REG, mask, ~f->n);
248 		if (ret)
249 			return ret;
250 	}
251 
252 	mask = BIT(rcg->hid_width) - 1;
253 	mask |= CFG_SRC_SEL_MASK | CFG_MODE_MASK;
254 	cfg = f->pre_div << CFG_SRC_DIV_SHIFT;
255 	cfg |= rcg->parent_map[f->src] << CFG_SRC_SEL_SHIFT;
256 	if (rcg->mnd_width && f->n)
257 		cfg |= CFG_MODE_DUAL_EDGE;
258 	ret = regmap_update_bits(rcg->clkr.regmap,
259 			rcg->cmd_rcgr + CFG_REG, mask, cfg);
260 	if (ret)
261 		return ret;
262 
263 	return update_config(rcg);
264 }
265 
266 static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
267 {
268 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
269 	const struct freq_tbl *f;
270 
271 	f = find_freq(rcg->freq_tbl, rate);
272 	if (!f)
273 		return -EINVAL;
274 
275 	return clk_rcg2_configure(rcg, f);
276 }
277 
278 static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
279 			    unsigned long parent_rate)
280 {
281 	return __clk_rcg2_set_rate(hw, rate);
282 }
283 
284 static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
285 		unsigned long rate, unsigned long parent_rate, u8 index)
286 {
287 	return __clk_rcg2_set_rate(hw, rate);
288 }
289 
290 const struct clk_ops clk_rcg2_ops = {
291 	.is_enabled = clk_rcg2_is_enabled,
292 	.get_parent = clk_rcg2_get_parent,
293 	.set_parent = clk_rcg2_set_parent,
294 	.recalc_rate = clk_rcg2_recalc_rate,
295 	.determine_rate = clk_rcg2_determine_rate,
296 	.set_rate = clk_rcg2_set_rate,
297 	.set_rate_and_parent = clk_rcg2_set_rate_and_parent,
298 };
299 EXPORT_SYMBOL_GPL(clk_rcg2_ops);
300 
301 struct frac_entry {
302 	int num;
303 	int den;
304 };
305 
306 static const struct frac_entry frac_table_675m[] = {	/* link rate of 270M */
307 	{ 52, 295 },	/* 119 M */
308 	{ 11, 57 },	/* 130.25 M */
309 	{ 63, 307 },	/* 138.50 M */
310 	{ 11, 50 },	/* 148.50 M */
311 	{ 47, 206 },	/* 154 M */
312 	{ 31, 100 },	/* 205.25 M */
313 	{ 107, 269 },	/* 268.50 M */
314 	{ },
315 };
316 
317 static struct frac_entry frac_table_810m[] = { /* Link rate of 162M */
318 	{ 31, 211 },	/* 119 M */
319 	{ 32, 199 },	/* 130.25 M */
320 	{ 63, 307 },	/* 138.50 M */
321 	{ 11, 60 },	/* 148.50 M */
322 	{ 50, 263 },	/* 154 M */
323 	{ 31, 120 },	/* 205.25 M */
324 	{ 119, 359 },	/* 268.50 M */
325 	{ },
326 };
327 
328 static int clk_edp_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
329 			      unsigned long parent_rate)
330 {
331 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
332 	struct freq_tbl f = *rcg->freq_tbl;
333 	const struct frac_entry *frac;
334 	int delta = 100000;
335 	s64 src_rate = parent_rate;
336 	s64 request;
337 	u32 mask = BIT(rcg->hid_width) - 1;
338 	u32 hid_div;
339 
340 	if (src_rate == 810000000)
341 		frac = frac_table_810m;
342 	else
343 		frac = frac_table_675m;
344 
345 	for (; frac->num; frac++) {
346 		request = rate;
347 		request *= frac->den;
348 		request = div_s64(request, frac->num);
349 		if ((src_rate < (request - delta)) ||
350 		    (src_rate > (request + delta)))
351 			continue;
352 
353 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
354 				&hid_div);
355 		f.pre_div = hid_div;
356 		f.pre_div >>= CFG_SRC_DIV_SHIFT;
357 		f.pre_div &= mask;
358 		f.m = frac->num;
359 		f.n = frac->den;
360 
361 		return clk_rcg2_configure(rcg, &f);
362 	}
363 
364 	return -EINVAL;
365 }
366 
367 static int clk_edp_pixel_set_rate_and_parent(struct clk_hw *hw,
368 		unsigned long rate, unsigned long parent_rate, u8 index)
369 {
370 	/* Parent index is set statically in frequency table */
371 	return clk_edp_pixel_set_rate(hw, rate, parent_rate);
372 }
373 
374 static long clk_edp_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
375 				 unsigned long *p_rate, struct clk **p)
376 {
377 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
378 	const struct freq_tbl *f = rcg->freq_tbl;
379 	const struct frac_entry *frac;
380 	int delta = 100000;
381 	s64 src_rate = *p_rate;
382 	s64 request;
383 	u32 mask = BIT(rcg->hid_width) - 1;
384 	u32 hid_div;
385 
386 	/* Force the correct parent */
387 	*p = clk_get_parent_by_index(hw->clk, f->src);
388 
389 	if (src_rate == 810000000)
390 		frac = frac_table_810m;
391 	else
392 		frac = frac_table_675m;
393 
394 	for (; frac->num; frac++) {
395 		request = rate;
396 		request *= frac->den;
397 		request = div_s64(request, frac->num);
398 		if ((src_rate < (request - delta)) ||
399 		    (src_rate > (request + delta)))
400 			continue;
401 
402 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
403 				&hid_div);
404 		hid_div >>= CFG_SRC_DIV_SHIFT;
405 		hid_div &= mask;
406 
407 		return calc_rate(src_rate, frac->num, frac->den, !!frac->den,
408 				 hid_div);
409 	}
410 
411 	return -EINVAL;
412 }
413 
414 const struct clk_ops clk_edp_pixel_ops = {
415 	.is_enabled = clk_rcg2_is_enabled,
416 	.get_parent = clk_rcg2_get_parent,
417 	.set_parent = clk_rcg2_set_parent,
418 	.recalc_rate = clk_rcg2_recalc_rate,
419 	.set_rate = clk_edp_pixel_set_rate,
420 	.set_rate_and_parent = clk_edp_pixel_set_rate_and_parent,
421 	.determine_rate = clk_edp_pixel_determine_rate,
422 };
423 EXPORT_SYMBOL_GPL(clk_edp_pixel_ops);
424 
425 static long clk_byte_determine_rate(struct clk_hw *hw, unsigned long rate,
426 			 unsigned long *p_rate, struct clk **p)
427 {
428 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
429 	const struct freq_tbl *f = rcg->freq_tbl;
430 	unsigned long parent_rate, div;
431 	u32 mask = BIT(rcg->hid_width) - 1;
432 
433 	if (rate == 0)
434 		return -EINVAL;
435 
436 	*p = clk_get_parent_by_index(hw->clk, f->src);
437 	*p_rate = parent_rate = __clk_round_rate(*p, rate);
438 
439 	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
440 	div = min_t(u32, div, mask);
441 
442 	return calc_rate(parent_rate, 0, 0, 0, div);
443 }
444 
445 static int clk_byte_set_rate(struct clk_hw *hw, unsigned long rate,
446 			 unsigned long parent_rate)
447 {
448 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
449 	struct freq_tbl f = *rcg->freq_tbl;
450 	unsigned long div;
451 	u32 mask = BIT(rcg->hid_width) - 1;
452 
453 	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
454 	div = min_t(u32, div, mask);
455 
456 	f.pre_div = div;
457 
458 	return clk_rcg2_configure(rcg, &f);
459 }
460 
461 static int clk_byte_set_rate_and_parent(struct clk_hw *hw,
462 		unsigned long rate, unsigned long parent_rate, u8 index)
463 {
464 	/* Parent index is set statically in frequency table */
465 	return clk_byte_set_rate(hw, rate, parent_rate);
466 }
467 
468 const struct clk_ops clk_byte_ops = {
469 	.is_enabled = clk_rcg2_is_enabled,
470 	.get_parent = clk_rcg2_get_parent,
471 	.set_parent = clk_rcg2_set_parent,
472 	.recalc_rate = clk_rcg2_recalc_rate,
473 	.set_rate = clk_byte_set_rate,
474 	.set_rate_and_parent = clk_byte_set_rate_and_parent,
475 	.determine_rate = clk_byte_determine_rate,
476 };
477 EXPORT_SYMBOL_GPL(clk_byte_ops);
478 
479 static const struct frac_entry frac_table_pixel[] = {
480 	{ 3, 8 },
481 	{ 2, 9 },
482 	{ 4, 9 },
483 	{ 1, 1 },
484 	{ }
485 };
486 
487 static long clk_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
488 				 unsigned long *p_rate, struct clk **p)
489 {
490 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
491 	unsigned long request, src_rate;
492 	int delta = 100000;
493 	const struct freq_tbl *f = rcg->freq_tbl;
494 	const struct frac_entry *frac = frac_table_pixel;
495 	struct clk *parent = *p = clk_get_parent_by_index(hw->clk, f->src);
496 
497 	for (; frac->num; frac++) {
498 		request = (rate * frac->den) / frac->num;
499 
500 		src_rate = __clk_round_rate(parent, request);
501 		if ((src_rate < (request - delta)) ||
502 			(src_rate > (request + delta)))
503 			continue;
504 
505 		*p_rate = src_rate;
506 		return (src_rate * frac->num) / frac->den;
507 	}
508 
509 	return -EINVAL;
510 }
511 
512 static int clk_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
513 		unsigned long parent_rate)
514 {
515 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
516 	struct freq_tbl f = *rcg->freq_tbl;
517 	const struct frac_entry *frac = frac_table_pixel;
518 	unsigned long request, src_rate;
519 	int delta = 100000;
520 	u32 mask = BIT(rcg->hid_width) - 1;
521 	u32 hid_div;
522 	struct clk *parent = clk_get_parent_by_index(hw->clk, f.src);
523 
524 	for (; frac->num; frac++) {
525 		request = (rate * frac->den) / frac->num;
526 
527 		src_rate = __clk_round_rate(parent, request);
528 		if ((src_rate < (request - delta)) ||
529 			(src_rate > (request + delta)))
530 			continue;
531 
532 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
533 				&hid_div);
534 		f.pre_div = hid_div;
535 		f.pre_div >>= CFG_SRC_DIV_SHIFT;
536 		f.pre_div &= mask;
537 		f.m = frac->num;
538 		f.n = frac->den;
539 
540 		return clk_rcg2_configure(rcg, &f);
541 	}
542 	return -EINVAL;
543 }
544 
545 static int clk_pixel_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
546 		unsigned long parent_rate, u8 index)
547 {
548 	/* Parent index is set statically in frequency table */
549 	return clk_pixel_set_rate(hw, rate, parent_rate);
550 }
551 
552 const struct clk_ops clk_pixel_ops = {
553 	.is_enabled = clk_rcg2_is_enabled,
554 	.get_parent = clk_rcg2_get_parent,
555 	.set_parent = clk_rcg2_set_parent,
556 	.recalc_rate = clk_rcg2_recalc_rate,
557 	.set_rate = clk_pixel_set_rate,
558 	.set_rate_and_parent = clk_pixel_set_rate_and_parent,
559 	.determine_rate = clk_pixel_determine_rate,
560 };
561 EXPORT_SYMBOL_GPL(clk_pixel_ops);
562