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
50static 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
63static 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		goto err;
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].cfg)
79			return i;
80
81err:
82	pr_debug("%s: Clock %s has invalid parent, using default.\n",
83		 __func__, __clk_get_name(hw->clk));
84	return 0;
85}
86
87static int update_config(struct clk_rcg2 *rcg)
88{
89	int count, ret;
90	u32 cmd;
91	struct clk_hw *hw = &rcg->clkr.hw;
92	const char *name = __clk_get_name(hw->clk);
93
94	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG,
95				 CMD_UPDATE, CMD_UPDATE);
96	if (ret)
97		return ret;
98
99	/* Wait for update to take effect */
100	for (count = 500; count > 0; count--) {
101		ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG, &cmd);
102		if (ret)
103			return ret;
104		if (!(cmd & CMD_UPDATE))
105			return 0;
106		udelay(1);
107	}
108
109	WARN(1, "%s: rcg didn't update its configuration.", name);
110	return 0;
111}
112
113static int clk_rcg2_set_parent(struct clk_hw *hw, u8 index)
114{
115	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
116	int ret;
117	u32 cfg = rcg->parent_map[index].cfg << CFG_SRC_SEL_SHIFT;
118
119	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
120				 CFG_SRC_SEL_MASK, cfg);
121	if (ret)
122		return ret;
123
124	return update_config(rcg);
125}
126
127/*
128 * Calculate m/n:d rate
129 *
130 *          parent_rate     m
131 *   rate = ----------- x  ---
132 *            hid_div       n
133 */
134static unsigned long
135calc_rate(unsigned long rate, u32 m, u32 n, u32 mode, u32 hid_div)
136{
137	if (hid_div) {
138		rate *= 2;
139		rate /= hid_div + 1;
140	}
141
142	if (mode) {
143		u64 tmp = rate;
144		tmp *= m;
145		do_div(tmp, n);
146		rate = tmp;
147	}
148
149	return rate;
150}
151
152static unsigned long
153clk_rcg2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
154{
155	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
156	u32 cfg, hid_div, m = 0, n = 0, mode = 0, mask;
157
158	regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, &cfg);
159
160	if (rcg->mnd_width) {
161		mask = BIT(rcg->mnd_width) - 1;
162		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + M_REG, &m);
163		m &= mask;
164		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + N_REG, &n);
165		n =  ~n;
166		n &= mask;
167		n += m;
168		mode = cfg & CFG_MODE_MASK;
169		mode >>= CFG_MODE_SHIFT;
170	}
171
172	mask = BIT(rcg->hid_width) - 1;
173	hid_div = cfg >> CFG_SRC_DIV_SHIFT;
174	hid_div &= mask;
175
176	return calc_rate(parent_rate, m, n, mode, hid_div);
177}
178
179static long _freq_tbl_determine_rate(struct clk_hw *hw,
180		const struct freq_tbl *f, unsigned long rate,
181		unsigned long *p_rate, struct clk_hw **p_hw)
182{
183	unsigned long clk_flags;
184	struct clk *p;
185	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
186	int index;
187
188	f = qcom_find_freq(f, rate);
189	if (!f)
190		return -EINVAL;
191
192	index = qcom_find_src_index(hw, rcg->parent_map, f->src);
193	if (index < 0)
194		return index;
195
196	clk_flags = __clk_get_flags(hw->clk);
197	p = clk_get_parent_by_index(hw->clk, index);
198	if (clk_flags & CLK_SET_RATE_PARENT) {
199		if (f->pre_div) {
200			rate /= 2;
201			rate *= f->pre_div + 1;
202		}
203
204		if (f->n) {
205			u64 tmp = rate;
206			tmp = tmp * f->n;
207			do_div(tmp, f->m);
208			rate = tmp;
209		}
210	} else {
211		rate =  __clk_get_rate(p);
212	}
213	*p_hw = __clk_get_hw(p);
214	*p_rate = rate;
215
216	return f->freq;
217}
218
219static long clk_rcg2_determine_rate(struct clk_hw *hw, unsigned long rate,
220		unsigned long min_rate, unsigned long max_rate,
221		unsigned long *p_rate, struct clk_hw **p)
222{
223	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
224
225	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, rate, p_rate, p);
226}
227
228static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
229{
230	u32 cfg, mask;
231	struct clk_hw *hw = &rcg->clkr.hw;
232	int ret, index = qcom_find_src_index(hw, rcg->parent_map, f->src);
233
234	if (index < 0)
235		return index;
236
237	if (rcg->mnd_width && f->n) {
238		mask = BIT(rcg->mnd_width) - 1;
239		ret = regmap_update_bits(rcg->clkr.regmap,
240				rcg->cmd_rcgr + M_REG, mask, f->m);
241		if (ret)
242			return ret;
243
244		ret = regmap_update_bits(rcg->clkr.regmap,
245				rcg->cmd_rcgr + N_REG, mask, ~(f->n - f->m));
246		if (ret)
247			return ret;
248
249		ret = regmap_update_bits(rcg->clkr.regmap,
250				rcg->cmd_rcgr + D_REG, mask, ~f->n);
251		if (ret)
252			return ret;
253	}
254
255	mask = BIT(rcg->hid_width) - 1;
256	mask |= CFG_SRC_SEL_MASK | CFG_MODE_MASK;
257	cfg = f->pre_div << CFG_SRC_DIV_SHIFT;
258	cfg |= rcg->parent_map[index].cfg << CFG_SRC_SEL_SHIFT;
259	if (rcg->mnd_width && f->n && (f->m != f->n))
260		cfg |= CFG_MODE_DUAL_EDGE;
261	ret = regmap_update_bits(rcg->clkr.regmap,
262			rcg->cmd_rcgr + CFG_REG, mask, cfg);
263	if (ret)
264		return ret;
265
266	return update_config(rcg);
267}
268
269static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
270{
271	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
272	const struct freq_tbl *f;
273
274	f = qcom_find_freq(rcg->freq_tbl, rate);
275	if (!f)
276		return -EINVAL;
277
278	return clk_rcg2_configure(rcg, f);
279}
280
281static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
282			    unsigned long parent_rate)
283{
284	return __clk_rcg2_set_rate(hw, rate);
285}
286
287static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
288		unsigned long rate, unsigned long parent_rate, u8 index)
289{
290	return __clk_rcg2_set_rate(hw, rate);
291}
292
293const struct clk_ops clk_rcg2_ops = {
294	.is_enabled = clk_rcg2_is_enabled,
295	.get_parent = clk_rcg2_get_parent,
296	.set_parent = clk_rcg2_set_parent,
297	.recalc_rate = clk_rcg2_recalc_rate,
298	.determine_rate = clk_rcg2_determine_rate,
299	.set_rate = clk_rcg2_set_rate,
300	.set_rate_and_parent = clk_rcg2_set_rate_and_parent,
301};
302EXPORT_SYMBOL_GPL(clk_rcg2_ops);
303
304struct frac_entry {
305	int num;
306	int den;
307};
308
309static const struct frac_entry frac_table_675m[] = {	/* link rate of 270M */
310	{ 52, 295 },	/* 119 M */
311	{ 11, 57 },	/* 130.25 M */
312	{ 63, 307 },	/* 138.50 M */
313	{ 11, 50 },	/* 148.50 M */
314	{ 47, 206 },	/* 154 M */
315	{ 31, 100 },	/* 205.25 M */
316	{ 107, 269 },	/* 268.50 M */
317	{ },
318};
319
320static struct frac_entry frac_table_810m[] = { /* Link rate of 162M */
321	{ 31, 211 },	/* 119 M */
322	{ 32, 199 },	/* 130.25 M */
323	{ 63, 307 },	/* 138.50 M */
324	{ 11, 60 },	/* 148.50 M */
325	{ 50, 263 },	/* 154 M */
326	{ 31, 120 },	/* 205.25 M */
327	{ 119, 359 },	/* 268.50 M */
328	{ },
329};
330
331static int clk_edp_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
332			      unsigned long parent_rate)
333{
334	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
335	struct freq_tbl f = *rcg->freq_tbl;
336	const struct frac_entry *frac;
337	int delta = 100000;
338	s64 src_rate = parent_rate;
339	s64 request;
340	u32 mask = BIT(rcg->hid_width) - 1;
341	u32 hid_div;
342
343	if (src_rate == 810000000)
344		frac = frac_table_810m;
345	else
346		frac = frac_table_675m;
347
348	for (; frac->num; frac++) {
349		request = rate;
350		request *= frac->den;
351		request = div_s64(request, frac->num);
352		if ((src_rate < (request - delta)) ||
353		    (src_rate > (request + delta)))
354			continue;
355
356		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
357				&hid_div);
358		f.pre_div = hid_div;
359		f.pre_div >>= CFG_SRC_DIV_SHIFT;
360		f.pre_div &= mask;
361		f.m = frac->num;
362		f.n = frac->den;
363
364		return clk_rcg2_configure(rcg, &f);
365	}
366
367	return -EINVAL;
368}
369
370static int clk_edp_pixel_set_rate_and_parent(struct clk_hw *hw,
371		unsigned long rate, unsigned long parent_rate, u8 index)
372{
373	/* Parent index is set statically in frequency table */
374	return clk_edp_pixel_set_rate(hw, rate, parent_rate);
375}
376
377static long clk_edp_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
378				 unsigned long min_rate,
379				 unsigned long max_rate,
380				 unsigned long *p_rate, struct clk_hw **p)
381{
382	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
383	const struct freq_tbl *f = rcg->freq_tbl;
384	const struct frac_entry *frac;
385	int delta = 100000;
386	s64 src_rate = *p_rate;
387	s64 request;
388	u32 mask = BIT(rcg->hid_width) - 1;
389	u32 hid_div;
390	int index = qcom_find_src_index(hw, rcg->parent_map, f->src);
391
392	/* Force the correct parent */
393	*p = __clk_get_hw(clk_get_parent_by_index(hw->clk, index));
394
395	if (src_rate == 810000000)
396		frac = frac_table_810m;
397	else
398		frac = frac_table_675m;
399
400	for (; frac->num; frac++) {
401		request = rate;
402		request *= frac->den;
403		request = div_s64(request, frac->num);
404		if ((src_rate < (request - delta)) ||
405		    (src_rate > (request + delta)))
406			continue;
407
408		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
409				&hid_div);
410		hid_div >>= CFG_SRC_DIV_SHIFT;
411		hid_div &= mask;
412
413		return calc_rate(src_rate, frac->num, frac->den, !!frac->den,
414				 hid_div);
415	}
416
417	return -EINVAL;
418}
419
420const struct clk_ops clk_edp_pixel_ops = {
421	.is_enabled = clk_rcg2_is_enabled,
422	.get_parent = clk_rcg2_get_parent,
423	.set_parent = clk_rcg2_set_parent,
424	.recalc_rate = clk_rcg2_recalc_rate,
425	.set_rate = clk_edp_pixel_set_rate,
426	.set_rate_and_parent = clk_edp_pixel_set_rate_and_parent,
427	.determine_rate = clk_edp_pixel_determine_rate,
428};
429EXPORT_SYMBOL_GPL(clk_edp_pixel_ops);
430
431static long clk_byte_determine_rate(struct clk_hw *hw, unsigned long rate,
432			 unsigned long min_rate, unsigned long max_rate,
433			 unsigned long *p_rate, struct clk_hw **p_hw)
434{
435	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
436	const struct freq_tbl *f = rcg->freq_tbl;
437	int index = qcom_find_src_index(hw, rcg->parent_map, f->src);
438	unsigned long parent_rate, div;
439	u32 mask = BIT(rcg->hid_width) - 1;
440	struct clk *p;
441
442	if (rate == 0)
443		return -EINVAL;
444
445	p = clk_get_parent_by_index(hw->clk, index);
446	*p_hw = __clk_get_hw(p);
447	*p_rate = parent_rate = __clk_round_rate(p, rate);
448
449	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
450	div = min_t(u32, div, mask);
451
452	return calc_rate(parent_rate, 0, 0, 0, div);
453}
454
455static int clk_byte_set_rate(struct clk_hw *hw, unsigned long rate,
456			 unsigned long parent_rate)
457{
458	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
459	struct freq_tbl f = *rcg->freq_tbl;
460	unsigned long div;
461	u32 mask = BIT(rcg->hid_width) - 1;
462
463	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
464	div = min_t(u32, div, mask);
465
466	f.pre_div = div;
467
468	return clk_rcg2_configure(rcg, &f);
469}
470
471static int clk_byte_set_rate_and_parent(struct clk_hw *hw,
472		unsigned long rate, unsigned long parent_rate, u8 index)
473{
474	/* Parent index is set statically in frequency table */
475	return clk_byte_set_rate(hw, rate, parent_rate);
476}
477
478const struct clk_ops clk_byte_ops = {
479	.is_enabled = clk_rcg2_is_enabled,
480	.get_parent = clk_rcg2_get_parent,
481	.set_parent = clk_rcg2_set_parent,
482	.recalc_rate = clk_rcg2_recalc_rate,
483	.set_rate = clk_byte_set_rate,
484	.set_rate_and_parent = clk_byte_set_rate_and_parent,
485	.determine_rate = clk_byte_determine_rate,
486};
487EXPORT_SYMBOL_GPL(clk_byte_ops);
488
489static const struct frac_entry frac_table_pixel[] = {
490	{ 3, 8 },
491	{ 2, 9 },
492	{ 4, 9 },
493	{ 1, 1 },
494	{ }
495};
496
497static long clk_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
498				 unsigned long min_rate,
499				 unsigned long max_rate,
500				 unsigned long *p_rate, struct clk_hw **p)
501{
502	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
503	unsigned long request, src_rate;
504	int delta = 100000;
505	const struct freq_tbl *f = rcg->freq_tbl;
506	const struct frac_entry *frac = frac_table_pixel;
507	int index = qcom_find_src_index(hw, rcg->parent_map, f->src);
508	struct clk *parent = clk_get_parent_by_index(hw->clk, index);
509
510	*p = __clk_get_hw(parent);
511
512	for (; frac->num; frac++) {
513		request = (rate * frac->den) / frac->num;
514
515		src_rate = __clk_round_rate(parent, request);
516		if ((src_rate < (request - delta)) ||
517			(src_rate > (request + delta)))
518			continue;
519
520		*p_rate = src_rate;
521		return (src_rate * frac->num) / frac->den;
522	}
523
524	return -EINVAL;
525}
526
527static int clk_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
528		unsigned long parent_rate)
529{
530	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
531	struct freq_tbl f = *rcg->freq_tbl;
532	const struct frac_entry *frac = frac_table_pixel;
533	unsigned long request;
534	int delta = 100000;
535	u32 mask = BIT(rcg->hid_width) - 1;
536	u32 hid_div;
537
538	for (; frac->num; frac++) {
539		request = (rate * frac->den) / frac->num;
540
541		if ((parent_rate < (request - delta)) ||
542			(parent_rate > (request + delta)))
543			continue;
544
545		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
546				&hid_div);
547		f.pre_div = hid_div;
548		f.pre_div >>= CFG_SRC_DIV_SHIFT;
549		f.pre_div &= mask;
550		f.m = frac->num;
551		f.n = frac->den;
552
553		return clk_rcg2_configure(rcg, &f);
554	}
555	return -EINVAL;
556}
557
558static int clk_pixel_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
559		unsigned long parent_rate, u8 index)
560{
561	/* Parent index is set statically in frequency table */
562	return clk_pixel_set_rate(hw, rate, parent_rate);
563}
564
565const struct clk_ops clk_pixel_ops = {
566	.is_enabled = clk_rcg2_is_enabled,
567	.get_parent = clk_rcg2_get_parent,
568	.set_parent = clk_rcg2_set_parent,
569	.recalc_rate = clk_rcg2_recalc_rate,
570	.set_rate = clk_pixel_set_rate,
571	.set_rate_and_parent = clk_pixel_set_rate_and_parent,
572	.determine_rate = clk_pixel_determine_rate,
573};
574EXPORT_SYMBOL_GPL(clk_pixel_ops);
575