1/*
2 * mmp mix(div and mux) clock operation source file
3 *
4 * Copyright (C) 2014 Marvell
5 * Chao Xie <chao.xie@marvell.com>
6 *
7 * This file is licensed under the terms of the GNU General Public
8 * License version 2. This program is licensed "as is" without any
9 * warranty of any kind, whether express or implied.
10 */
11
12#include <linux/clk-provider.h>
13#include <linux/slab.h>
14#include <linux/io.h>
15#include <linux/err.h>
16
17#include "clk.h"
18
19/*
20 * The mix clock is a clock combined mux and div type clock.
21 * Because the div field and mux field need to be set at same
22 * time, we can not divide it into 2 types of clock
23 */
24
25#define to_clk_mix(hw)	container_of(hw, struct mmp_clk_mix, hw)
26
27static unsigned int _get_maxdiv(struct mmp_clk_mix *mix)
28{
29	unsigned int div_mask = (1 << mix->reg_info.width_div) - 1;
30	unsigned int maxdiv = 0;
31	struct clk_div_table *clkt;
32
33	if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
34		return div_mask;
35	if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
36		return 1 << div_mask;
37	if (mix->div_table) {
38		for (clkt = mix->div_table; clkt->div; clkt++)
39			if (clkt->div > maxdiv)
40				maxdiv = clkt->div;
41		return maxdiv;
42	}
43	return div_mask + 1;
44}
45
46static unsigned int _get_div(struct mmp_clk_mix *mix, unsigned int val)
47{
48	struct clk_div_table *clkt;
49
50	if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
51		return val;
52	if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
53		return 1 << val;
54	if (mix->div_table) {
55		for (clkt = mix->div_table; clkt->div; clkt++)
56			if (clkt->val == val)
57				return clkt->div;
58		if (clkt->div == 0)
59			return 0;
60	}
61	return val + 1;
62}
63
64static unsigned int _get_mux(struct mmp_clk_mix *mix, unsigned int val)
65{
66	int num_parents = __clk_get_num_parents(mix->hw.clk);
67	int i;
68
69	if (mix->mux_flags & CLK_MUX_INDEX_BIT)
70		return ffs(val) - 1;
71	if (mix->mux_flags & CLK_MUX_INDEX_ONE)
72		return val - 1;
73	if (mix->mux_table) {
74		for (i = 0; i < num_parents; i++)
75			if (mix->mux_table[i] == val)
76				return i;
77		if (i == num_parents)
78			return 0;
79	}
80
81	return val;
82}
83static unsigned int _get_div_val(struct mmp_clk_mix *mix, unsigned int div)
84{
85	struct clk_div_table *clkt;
86
87	if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
88		return div;
89	if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
90		return __ffs(div);
91	if (mix->div_table) {
92		for (clkt = mix->div_table; clkt->div; clkt++)
93			if (clkt->div == div)
94				return clkt->val;
95		if (clkt->div == 0)
96			return 0;
97	}
98
99	return div - 1;
100}
101
102static unsigned int _get_mux_val(struct mmp_clk_mix *mix, unsigned int mux)
103{
104	if (mix->mux_table)
105		return mix->mux_table[mux];
106
107	return mux;
108}
109
110static void _filter_clk_table(struct mmp_clk_mix *mix,
111				struct mmp_clk_mix_clk_table *table,
112				unsigned int table_size)
113{
114	int i;
115	struct mmp_clk_mix_clk_table *item;
116	struct clk *parent, *clk;
117	unsigned long parent_rate;
118
119	clk = mix->hw.clk;
120
121	for (i = 0; i < table_size; i++) {
122		item = &table[i];
123		parent = clk_get_parent_by_index(clk, item->parent_index);
124		parent_rate = __clk_get_rate(parent);
125		if (parent_rate % item->rate) {
126			item->valid = 0;
127		} else {
128			item->divisor = parent_rate / item->rate;
129			item->valid = 1;
130		}
131	}
132}
133
134static int _set_rate(struct mmp_clk_mix *mix, u32 mux_val, u32 div_val,
135			unsigned int change_mux, unsigned int change_div)
136{
137	struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
138	u8 width, shift;
139	u32 mux_div, fc_req;
140	int ret, timeout = 50;
141	unsigned long flags = 0;
142
143	if (!change_mux && !change_div)
144		return -EINVAL;
145
146	if (mix->lock)
147		spin_lock_irqsave(mix->lock, flags);
148
149	if (mix->type == MMP_CLK_MIX_TYPE_V1
150		|| mix->type == MMP_CLK_MIX_TYPE_V2)
151		mux_div = readl(ri->reg_clk_ctrl);
152	else
153		mux_div = readl(ri->reg_clk_sel);
154
155	if (change_div) {
156		width = ri->width_div;
157		shift = ri->shift_div;
158		mux_div &= ~MMP_CLK_BITS_MASK(width, shift);
159		mux_div |= MMP_CLK_BITS_SET_VAL(div_val, width, shift);
160	}
161
162	if (change_mux) {
163		width = ri->width_mux;
164		shift = ri->shift_mux;
165		mux_div &= ~MMP_CLK_BITS_MASK(width, shift);
166		mux_div |= MMP_CLK_BITS_SET_VAL(mux_val, width, shift);
167	}
168
169	if (mix->type == MMP_CLK_MIX_TYPE_V1) {
170		writel(mux_div, ri->reg_clk_ctrl);
171	} else if (mix->type == MMP_CLK_MIX_TYPE_V2) {
172		mux_div |= (1 << ri->bit_fc);
173		writel(mux_div, ri->reg_clk_ctrl);
174
175		do {
176			fc_req = readl(ri->reg_clk_ctrl);
177			timeout--;
178			if (!(fc_req & (1 << ri->bit_fc)))
179				break;
180		} while (timeout);
181
182		if (timeout == 0) {
183			pr_err("%s:%s cannot do frequency change\n",
184				__func__, __clk_get_name(mix->hw.clk));
185			ret = -EBUSY;
186			goto error;
187		}
188	} else {
189		fc_req = readl(ri->reg_clk_ctrl);
190		fc_req |= 1 << ri->bit_fc;
191		writel(fc_req, ri->reg_clk_ctrl);
192		writel(mux_div, ri->reg_clk_sel);
193		fc_req &= ~(1 << ri->bit_fc);
194	}
195
196	ret = 0;
197error:
198	if (mix->lock)
199		spin_unlock_irqrestore(mix->lock, flags);
200
201	return ret;
202}
203
204static long mmp_clk_mix_determine_rate(struct clk_hw *hw, unsigned long rate,
205					unsigned long min_rate,
206					unsigned long max_rate,
207					unsigned long *best_parent_rate,
208					struct clk_hw **best_parent_clk)
209{
210	struct mmp_clk_mix *mix = to_clk_mix(hw);
211	struct mmp_clk_mix_clk_table *item;
212	struct clk *parent, *parent_best, *mix_clk;
213	unsigned long parent_rate, mix_rate, mix_rate_best, parent_rate_best;
214	unsigned long gap, gap_best;
215	u32 div_val_max;
216	unsigned int div;
217	int i, j;
218
219	mix_clk = hw->clk;
220
221	parent = NULL;
222	mix_rate_best = 0;
223	parent_rate_best = 0;
224	gap_best = rate;
225	parent_best = NULL;
226
227	if (mix->table) {
228		for (i = 0; i < mix->table_size; i++) {
229			item = &mix->table[i];
230			if (item->valid == 0)
231				continue;
232			parent = clk_get_parent_by_index(mix_clk,
233							item->parent_index);
234			parent_rate = __clk_get_rate(parent);
235			mix_rate = parent_rate / item->divisor;
236			gap = abs(mix_rate - rate);
237			if (parent_best == NULL || gap < gap_best) {
238				parent_best = parent;
239				parent_rate_best = parent_rate;
240				mix_rate_best = mix_rate;
241				gap_best = gap;
242				if (gap_best == 0)
243					goto found;
244			}
245		}
246	} else {
247		for (i = 0; i < __clk_get_num_parents(mix_clk); i++) {
248			parent = clk_get_parent_by_index(mix_clk, i);
249			parent_rate = __clk_get_rate(parent);
250			div_val_max = _get_maxdiv(mix);
251			for (j = 0; j < div_val_max; j++) {
252				div = _get_div(mix, j);
253				mix_rate = parent_rate / div;
254				gap = abs(mix_rate - rate);
255				if (parent_best == NULL || gap < gap_best) {
256					parent_best = parent;
257					parent_rate_best = parent_rate;
258					mix_rate_best = mix_rate;
259					gap_best = gap;
260					if (gap_best == 0)
261						goto found;
262				}
263			}
264		}
265	}
266
267found:
268	*best_parent_rate = parent_rate_best;
269	*best_parent_clk = __clk_get_hw(parent_best);
270
271	return mix_rate_best;
272}
273
274static int mmp_clk_mix_set_rate_and_parent(struct clk_hw *hw,
275						unsigned long rate,
276						unsigned long parent_rate,
277						u8 index)
278{
279	struct mmp_clk_mix *mix = to_clk_mix(hw);
280	unsigned int div;
281	u32 div_val, mux_val;
282
283	div = parent_rate / rate;
284	div_val = _get_div_val(mix, div);
285	mux_val = _get_mux_val(mix, index);
286
287	return _set_rate(mix, mux_val, div_val, 1, 1);
288}
289
290static u8 mmp_clk_mix_get_parent(struct clk_hw *hw)
291{
292	struct mmp_clk_mix *mix = to_clk_mix(hw);
293	struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
294	unsigned long flags = 0;
295	u32 mux_div = 0;
296	u8 width, shift;
297	u32 mux_val;
298
299	if (mix->lock)
300		spin_lock_irqsave(mix->lock, flags);
301
302	if (mix->type == MMP_CLK_MIX_TYPE_V1
303		|| mix->type == MMP_CLK_MIX_TYPE_V2)
304		mux_div = readl(ri->reg_clk_ctrl);
305	else
306		mux_div = readl(ri->reg_clk_sel);
307
308	if (mix->lock)
309		spin_unlock_irqrestore(mix->lock, flags);
310
311	width = mix->reg_info.width_mux;
312	shift = mix->reg_info.shift_mux;
313
314	mux_val = MMP_CLK_BITS_GET_VAL(mux_div, width, shift);
315
316	return _get_mux(mix, mux_val);
317}
318
319static unsigned long mmp_clk_mix_recalc_rate(struct clk_hw *hw,
320					unsigned long parent_rate)
321{
322	struct mmp_clk_mix *mix = to_clk_mix(hw);
323	struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
324	unsigned long flags = 0;
325	u32 mux_div = 0;
326	u8 width, shift;
327	unsigned int div;
328
329	if (mix->lock)
330		spin_lock_irqsave(mix->lock, flags);
331
332	if (mix->type == MMP_CLK_MIX_TYPE_V1
333		|| mix->type == MMP_CLK_MIX_TYPE_V2)
334		mux_div = readl(ri->reg_clk_ctrl);
335	else
336		mux_div = readl(ri->reg_clk_sel);
337
338	if (mix->lock)
339		spin_unlock_irqrestore(mix->lock, flags);
340
341	width = mix->reg_info.width_div;
342	shift = mix->reg_info.shift_div;
343
344	div = _get_div(mix, MMP_CLK_BITS_GET_VAL(mux_div, width, shift));
345
346	return parent_rate / div;
347}
348
349static int mmp_clk_set_parent(struct clk_hw *hw, u8 index)
350{
351	struct mmp_clk_mix *mix = to_clk_mix(hw);
352	struct mmp_clk_mix_clk_table *item;
353	int i;
354	u32 div_val, mux_val;
355
356	if (mix->table) {
357		for (i = 0; i < mix->table_size; i++) {
358			item = &mix->table[i];
359			if (item->valid == 0)
360				continue;
361			if (item->parent_index == index)
362				break;
363		}
364		if (i < mix->table_size) {
365			div_val = _get_div_val(mix, item->divisor);
366			mux_val = _get_mux_val(mix, item->parent_index);
367		} else
368			return -EINVAL;
369	} else {
370		mux_val = _get_mux_val(mix, index);
371		div_val = 0;
372	}
373
374	return _set_rate(mix, mux_val, div_val, 1, div_val ? 1 : 0);
375}
376
377static int mmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
378				unsigned long best_parent_rate)
379{
380	struct mmp_clk_mix *mix = to_clk_mix(hw);
381	struct mmp_clk_mix_clk_table *item;
382	unsigned long parent_rate;
383	unsigned int best_divisor;
384	struct clk *mix_clk, *parent;
385	int i;
386
387	best_divisor = best_parent_rate / rate;
388
389	mix_clk = hw->clk;
390	if (mix->table) {
391		for (i = 0; i < mix->table_size; i++) {
392			item = &mix->table[i];
393			if (item->valid == 0)
394				continue;
395			parent = clk_get_parent_by_index(mix_clk,
396							item->parent_index);
397			parent_rate = __clk_get_rate(parent);
398			if (parent_rate == best_parent_rate
399				&& item->divisor == best_divisor)
400				break;
401		}
402		if (i < mix->table_size)
403			return _set_rate(mix,
404					_get_mux_val(mix, item->parent_index),
405					_get_div_val(mix, item->divisor),
406					1, 1);
407		else
408			return -EINVAL;
409	} else {
410		for (i = 0; i < __clk_get_num_parents(mix_clk); i++) {
411			parent = clk_get_parent_by_index(mix_clk, i);
412			parent_rate = __clk_get_rate(parent);
413			if (parent_rate == best_parent_rate)
414				break;
415		}
416		if (i < __clk_get_num_parents(mix_clk))
417			return _set_rate(mix, _get_mux_val(mix, i),
418					_get_div_val(mix, best_divisor), 1, 1);
419		else
420			return -EINVAL;
421	}
422}
423
424static void mmp_clk_mix_init(struct clk_hw *hw)
425{
426	struct mmp_clk_mix *mix = to_clk_mix(hw);
427
428	if (mix->table)
429		_filter_clk_table(mix, mix->table, mix->table_size);
430}
431
432const struct clk_ops mmp_clk_mix_ops = {
433	.determine_rate = mmp_clk_mix_determine_rate,
434	.set_rate_and_parent = mmp_clk_mix_set_rate_and_parent,
435	.set_rate = mmp_clk_set_rate,
436	.set_parent = mmp_clk_set_parent,
437	.get_parent = mmp_clk_mix_get_parent,
438	.recalc_rate = mmp_clk_mix_recalc_rate,
439	.init = mmp_clk_mix_init,
440};
441
442struct clk *mmp_clk_register_mix(struct device *dev,
443					const char *name,
444					const char **parent_names,
445					u8 num_parents,
446					unsigned long flags,
447					struct mmp_clk_mix_config *config,
448					spinlock_t *lock)
449{
450	struct mmp_clk_mix *mix;
451	struct clk *clk;
452	struct clk_init_data init;
453	size_t table_bytes;
454
455	mix = kzalloc(sizeof(*mix), GFP_KERNEL);
456	if (!mix) {
457		pr_err("%s:%s: could not allocate mmp mix clk\n",
458			__func__, name);
459		return ERR_PTR(-ENOMEM);
460	}
461
462	init.name = name;
463	init.flags = flags | CLK_GET_RATE_NOCACHE;
464	init.parent_names = parent_names;
465	init.num_parents = num_parents;
466	init.ops = &mmp_clk_mix_ops;
467
468	memcpy(&mix->reg_info, &config->reg_info, sizeof(config->reg_info));
469	if (config->table) {
470		table_bytes = sizeof(*config->table) * config->table_size;
471		mix->table = kzalloc(table_bytes, GFP_KERNEL);
472		if (!mix->table) {
473			pr_err("%s:%s: could not allocate mmp mix table\n",
474				__func__, name);
475			kfree(mix);
476			return ERR_PTR(-ENOMEM);
477		}
478		memcpy(mix->table, config->table, table_bytes);
479		mix->table_size = config->table_size;
480	}
481
482	if (config->mux_table) {
483		table_bytes = sizeof(u32) * num_parents;
484		mix->mux_table = kzalloc(table_bytes, GFP_KERNEL);
485		if (!mix->mux_table) {
486			pr_err("%s:%s: could not allocate mmp mix mux-table\n",
487				__func__, name);
488			kfree(mix->table);
489			kfree(mix);
490			return ERR_PTR(-ENOMEM);
491		}
492		memcpy(mix->mux_table, config->mux_table, table_bytes);
493	}
494
495	mix->div_flags = config->div_flags;
496	mix->mux_flags = config->mux_flags;
497	mix->lock = lock;
498	mix->hw.init = &init;
499
500	if (config->reg_info.bit_fc >= 32)
501		mix->type = MMP_CLK_MIX_TYPE_V1;
502	else if (config->reg_info.reg_clk_sel)
503		mix->type = MMP_CLK_MIX_TYPE_V3;
504	else
505		mix->type = MMP_CLK_MIX_TYPE_V2;
506	clk = clk_register(dev, &mix->hw);
507
508	if (IS_ERR(clk)) {
509		kfree(mix->mux_table);
510		kfree(mix->table);
511		kfree(mix);
512	}
513
514	return clk;
515}
516