xref: /openbmc/linux/drivers/clk/qcom/clk-rcg2.c (revision 270384cc)
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 *p_rate, struct clk_hw **p)
212 {
213 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
214 
215 	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, rate, p_rate, p);
216 }
217 
218 static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
219 {
220 	u32 cfg, mask;
221 	int ret;
222 
223 	if (rcg->mnd_width && f->n) {
224 		mask = BIT(rcg->mnd_width) - 1;
225 		ret = regmap_update_bits(rcg->clkr.regmap,
226 				rcg->cmd_rcgr + M_REG, mask, f->m);
227 		if (ret)
228 			return ret;
229 
230 		ret = regmap_update_bits(rcg->clkr.regmap,
231 				rcg->cmd_rcgr + N_REG, mask, ~(f->n - f->m));
232 		if (ret)
233 			return ret;
234 
235 		ret = regmap_update_bits(rcg->clkr.regmap,
236 				rcg->cmd_rcgr + D_REG, mask, ~f->n);
237 		if (ret)
238 			return ret;
239 	}
240 
241 	mask = BIT(rcg->hid_width) - 1;
242 	mask |= CFG_SRC_SEL_MASK | CFG_MODE_MASK;
243 	cfg = f->pre_div << CFG_SRC_DIV_SHIFT;
244 	cfg |= rcg->parent_map[f->src] << CFG_SRC_SEL_SHIFT;
245 	if (rcg->mnd_width && f->n)
246 		cfg |= CFG_MODE_DUAL_EDGE;
247 	ret = regmap_update_bits(rcg->clkr.regmap,
248 			rcg->cmd_rcgr + CFG_REG, mask, cfg);
249 	if (ret)
250 		return ret;
251 
252 	return update_config(rcg);
253 }
254 
255 static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
256 {
257 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
258 	const struct freq_tbl *f;
259 
260 	f = qcom_find_freq(rcg->freq_tbl, rate);
261 	if (!f)
262 		return -EINVAL;
263 
264 	return clk_rcg2_configure(rcg, f);
265 }
266 
267 static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
268 			    unsigned long parent_rate)
269 {
270 	return __clk_rcg2_set_rate(hw, rate);
271 }
272 
273 static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
274 		unsigned long rate, unsigned long parent_rate, u8 index)
275 {
276 	return __clk_rcg2_set_rate(hw, rate);
277 }
278 
279 const struct clk_ops clk_rcg2_ops = {
280 	.is_enabled = clk_rcg2_is_enabled,
281 	.get_parent = clk_rcg2_get_parent,
282 	.set_parent = clk_rcg2_set_parent,
283 	.recalc_rate = clk_rcg2_recalc_rate,
284 	.determine_rate = clk_rcg2_determine_rate,
285 	.set_rate = clk_rcg2_set_rate,
286 	.set_rate_and_parent = clk_rcg2_set_rate_and_parent,
287 };
288 EXPORT_SYMBOL_GPL(clk_rcg2_ops);
289 
290 struct frac_entry {
291 	int num;
292 	int den;
293 };
294 
295 static const struct frac_entry frac_table_675m[] = {	/* link rate of 270M */
296 	{ 52, 295 },	/* 119 M */
297 	{ 11, 57 },	/* 130.25 M */
298 	{ 63, 307 },	/* 138.50 M */
299 	{ 11, 50 },	/* 148.50 M */
300 	{ 47, 206 },	/* 154 M */
301 	{ 31, 100 },	/* 205.25 M */
302 	{ 107, 269 },	/* 268.50 M */
303 	{ },
304 };
305 
306 static struct frac_entry frac_table_810m[] = { /* Link rate of 162M */
307 	{ 31, 211 },	/* 119 M */
308 	{ 32, 199 },	/* 130.25 M */
309 	{ 63, 307 },	/* 138.50 M */
310 	{ 11, 60 },	/* 148.50 M */
311 	{ 50, 263 },	/* 154 M */
312 	{ 31, 120 },	/* 205.25 M */
313 	{ 119, 359 },	/* 268.50 M */
314 	{ },
315 };
316 
317 static int clk_edp_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
318 			      unsigned long parent_rate)
319 {
320 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
321 	struct freq_tbl f = *rcg->freq_tbl;
322 	const struct frac_entry *frac;
323 	int delta = 100000;
324 	s64 src_rate = parent_rate;
325 	s64 request;
326 	u32 mask = BIT(rcg->hid_width) - 1;
327 	u32 hid_div;
328 
329 	if (src_rate == 810000000)
330 		frac = frac_table_810m;
331 	else
332 		frac = frac_table_675m;
333 
334 	for (; frac->num; frac++) {
335 		request = rate;
336 		request *= frac->den;
337 		request = div_s64(request, frac->num);
338 		if ((src_rate < (request - delta)) ||
339 		    (src_rate > (request + delta)))
340 			continue;
341 
342 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
343 				&hid_div);
344 		f.pre_div = hid_div;
345 		f.pre_div >>= CFG_SRC_DIV_SHIFT;
346 		f.pre_div &= mask;
347 		f.m = frac->num;
348 		f.n = frac->den;
349 
350 		return clk_rcg2_configure(rcg, &f);
351 	}
352 
353 	return -EINVAL;
354 }
355 
356 static int clk_edp_pixel_set_rate_and_parent(struct clk_hw *hw,
357 		unsigned long rate, unsigned long parent_rate, u8 index)
358 {
359 	/* Parent index is set statically in frequency table */
360 	return clk_edp_pixel_set_rate(hw, rate, parent_rate);
361 }
362 
363 static long clk_edp_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
364 				 unsigned long *p_rate, struct clk_hw **p)
365 {
366 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
367 	const struct freq_tbl *f = rcg->freq_tbl;
368 	const struct frac_entry *frac;
369 	int delta = 100000;
370 	s64 src_rate = *p_rate;
371 	s64 request;
372 	u32 mask = BIT(rcg->hid_width) - 1;
373 	u32 hid_div;
374 
375 	/* Force the correct parent */
376 	*p = __clk_get_hw(clk_get_parent_by_index(hw->clk, f->src));
377 
378 	if (src_rate == 810000000)
379 		frac = frac_table_810m;
380 	else
381 		frac = frac_table_675m;
382 
383 	for (; frac->num; frac++) {
384 		request = rate;
385 		request *= frac->den;
386 		request = div_s64(request, frac->num);
387 		if ((src_rate < (request - delta)) ||
388 		    (src_rate > (request + delta)))
389 			continue;
390 
391 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
392 				&hid_div);
393 		hid_div >>= CFG_SRC_DIV_SHIFT;
394 		hid_div &= mask;
395 
396 		return calc_rate(src_rate, frac->num, frac->den, !!frac->den,
397 				 hid_div);
398 	}
399 
400 	return -EINVAL;
401 }
402 
403 const struct clk_ops clk_edp_pixel_ops = {
404 	.is_enabled = clk_rcg2_is_enabled,
405 	.get_parent = clk_rcg2_get_parent,
406 	.set_parent = clk_rcg2_set_parent,
407 	.recalc_rate = clk_rcg2_recalc_rate,
408 	.set_rate = clk_edp_pixel_set_rate,
409 	.set_rate_and_parent = clk_edp_pixel_set_rate_and_parent,
410 	.determine_rate = clk_edp_pixel_determine_rate,
411 };
412 EXPORT_SYMBOL_GPL(clk_edp_pixel_ops);
413 
414 static long clk_byte_determine_rate(struct clk_hw *hw, unsigned long rate,
415 			 unsigned long *p_rate, struct clk_hw **p_hw)
416 {
417 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
418 	const struct freq_tbl *f = rcg->freq_tbl;
419 	unsigned long parent_rate, div;
420 	u32 mask = BIT(rcg->hid_width) - 1;
421 	struct clk *p;
422 
423 	if (rate == 0)
424 		return -EINVAL;
425 
426 	p = clk_get_parent_by_index(hw->clk, f->src);
427 	*p_hw = __clk_get_hw(p);
428 	*p_rate = parent_rate = __clk_round_rate(p, rate);
429 
430 	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
431 	div = min_t(u32, div, mask);
432 
433 	return calc_rate(parent_rate, 0, 0, 0, div);
434 }
435 
436 static int clk_byte_set_rate(struct clk_hw *hw, unsigned long rate,
437 			 unsigned long parent_rate)
438 {
439 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
440 	struct freq_tbl f = *rcg->freq_tbl;
441 	unsigned long div;
442 	u32 mask = BIT(rcg->hid_width) - 1;
443 
444 	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
445 	div = min_t(u32, div, mask);
446 
447 	f.pre_div = div;
448 
449 	return clk_rcg2_configure(rcg, &f);
450 }
451 
452 static int clk_byte_set_rate_and_parent(struct clk_hw *hw,
453 		unsigned long rate, unsigned long parent_rate, u8 index)
454 {
455 	/* Parent index is set statically in frequency table */
456 	return clk_byte_set_rate(hw, rate, parent_rate);
457 }
458 
459 const struct clk_ops clk_byte_ops = {
460 	.is_enabled = clk_rcg2_is_enabled,
461 	.get_parent = clk_rcg2_get_parent,
462 	.set_parent = clk_rcg2_set_parent,
463 	.recalc_rate = clk_rcg2_recalc_rate,
464 	.set_rate = clk_byte_set_rate,
465 	.set_rate_and_parent = clk_byte_set_rate_and_parent,
466 	.determine_rate = clk_byte_determine_rate,
467 };
468 EXPORT_SYMBOL_GPL(clk_byte_ops);
469 
470 static const struct frac_entry frac_table_pixel[] = {
471 	{ 3, 8 },
472 	{ 2, 9 },
473 	{ 4, 9 },
474 	{ 1, 1 },
475 	{ }
476 };
477 
478 static long clk_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
479 				 unsigned long *p_rate, struct clk_hw **p)
480 {
481 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
482 	unsigned long request, src_rate;
483 	int delta = 100000;
484 	const struct freq_tbl *f = rcg->freq_tbl;
485 	const struct frac_entry *frac = frac_table_pixel;
486 	struct clk *parent = clk_get_parent_by_index(hw->clk, f->src);
487 
488 	*p = __clk_get_hw(parent);
489 
490 	for (; frac->num; frac++) {
491 		request = (rate * frac->den) / frac->num;
492 
493 		src_rate = __clk_round_rate(parent, request);
494 		if ((src_rate < (request - delta)) ||
495 			(src_rate > (request + delta)))
496 			continue;
497 
498 		*p_rate = src_rate;
499 		return (src_rate * frac->num) / frac->den;
500 	}
501 
502 	return -EINVAL;
503 }
504 
505 static int clk_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
506 		unsigned long parent_rate)
507 {
508 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
509 	struct freq_tbl f = *rcg->freq_tbl;
510 	const struct frac_entry *frac = frac_table_pixel;
511 	unsigned long request, src_rate;
512 	int delta = 100000;
513 	u32 mask = BIT(rcg->hid_width) - 1;
514 	u32 hid_div;
515 	struct clk *parent = clk_get_parent_by_index(hw->clk, f.src);
516 
517 	for (; frac->num; frac++) {
518 		request = (rate * frac->den) / frac->num;
519 
520 		src_rate = __clk_round_rate(parent, request);
521 		if ((src_rate < (request - delta)) ||
522 			(src_rate > (request + delta)))
523 			continue;
524 
525 		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
526 				&hid_div);
527 		f.pre_div = hid_div;
528 		f.pre_div >>= CFG_SRC_DIV_SHIFT;
529 		f.pre_div &= mask;
530 		f.m = frac->num;
531 		f.n = frac->den;
532 
533 		return clk_rcg2_configure(rcg, &f);
534 	}
535 	return -EINVAL;
536 }
537 
538 static int clk_pixel_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
539 		unsigned long parent_rate, u8 index)
540 {
541 	/* Parent index is set statically in frequency table */
542 	return clk_pixel_set_rate(hw, rate, parent_rate);
543 }
544 
545 const struct clk_ops clk_pixel_ops = {
546 	.is_enabled = clk_rcg2_is_enabled,
547 	.get_parent = clk_rcg2_get_parent,
548 	.set_parent = clk_rcg2_set_parent,
549 	.recalc_rate = clk_rcg2_recalc_rate,
550 	.set_rate = clk_pixel_set_rate,
551 	.set_rate_and_parent = clk_pixel_set_rate_and_parent,
552 	.determine_rate = clk_pixel_determine_rate,
553 };
554 EXPORT_SYMBOL_GPL(clk_pixel_ops);
555