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_hw_get_num_parents(&mix->hw);
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_hw *parent, *hw;
117	unsigned long parent_rate;
118
119	hw = &mix->hw;
120
121	for (i = 0; i < table_size; i++) {
122		item = &table[i];
123		parent = clk_hw_get_parent_by_index(hw, item->parent_index);
124		parent_rate = clk_hw_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_hw_get_name(&mix->hw));
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 int mmp_clk_mix_determine_rate(struct clk_hw *hw,
205				      struct clk_rate_request *req)
206{
207	struct mmp_clk_mix *mix = to_clk_mix(hw);
208	struct mmp_clk_mix_clk_table *item;
209	struct clk_hw *parent, *parent_best;
210	unsigned long parent_rate, mix_rate, mix_rate_best, parent_rate_best;
211	unsigned long gap, gap_best;
212	u32 div_val_max;
213	unsigned int div;
214	int i, j;
215
216
217	mix_rate_best = 0;
218	parent_rate_best = 0;
219	gap_best = ULONG_MAX;
220	parent_best = NULL;
221
222	if (mix->table) {
223		for (i = 0; i < mix->table_size; i++) {
224			item = &mix->table[i];
225			if (item->valid == 0)
226				continue;
227			parent = clk_hw_get_parent_by_index(hw,
228							item->parent_index);
229			parent_rate = clk_hw_get_rate(parent);
230			mix_rate = parent_rate / item->divisor;
231			gap = abs(mix_rate - req->rate);
232			if (parent_best == NULL || gap < gap_best) {
233				parent_best = parent;
234				parent_rate_best = parent_rate;
235				mix_rate_best = mix_rate;
236				gap_best = gap;
237				if (gap_best == 0)
238					goto found;
239			}
240		}
241	} else {
242		for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
243			parent = clk_hw_get_parent_by_index(hw, i);
244			parent_rate = clk_hw_get_rate(parent);
245			div_val_max = _get_maxdiv(mix);
246			for (j = 0; j < div_val_max; j++) {
247				div = _get_div(mix, j);
248				mix_rate = parent_rate / div;
249				gap = abs(mix_rate - req->rate);
250				if (parent_best == NULL || gap < gap_best) {
251					parent_best = parent;
252					parent_rate_best = parent_rate;
253					mix_rate_best = mix_rate;
254					gap_best = gap;
255					if (gap_best == 0)
256						goto found;
257				}
258			}
259		}
260	}
261
262found:
263	if (!parent_best)
264		return -EINVAL;
265
266	req->best_parent_rate = parent_rate_best;
267	req->best_parent_hw = parent_best;
268	req->rate = mix_rate_best;
269
270	return 0;
271}
272
273static int mmp_clk_mix_set_rate_and_parent(struct clk_hw *hw,
274						unsigned long rate,
275						unsigned long parent_rate,
276						u8 index)
277{
278	struct mmp_clk_mix *mix = to_clk_mix(hw);
279	unsigned int div;
280	u32 div_val, mux_val;
281
282	div = parent_rate / rate;
283	div_val = _get_div_val(mix, div);
284	mux_val = _get_mux_val(mix, index);
285
286	return _set_rate(mix, mux_val, div_val, 1, 1);
287}
288
289static u8 mmp_clk_mix_get_parent(struct clk_hw *hw)
290{
291	struct mmp_clk_mix *mix = to_clk_mix(hw);
292	struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
293	unsigned long flags = 0;
294	u32 mux_div = 0;
295	u8 width, shift;
296	u32 mux_val;
297
298	if (mix->lock)
299		spin_lock_irqsave(mix->lock, flags);
300
301	if (mix->type == MMP_CLK_MIX_TYPE_V1
302		|| mix->type == MMP_CLK_MIX_TYPE_V2)
303		mux_div = readl(ri->reg_clk_ctrl);
304	else
305		mux_div = readl(ri->reg_clk_sel);
306
307	if (mix->lock)
308		spin_unlock_irqrestore(mix->lock, flags);
309
310	width = mix->reg_info.width_mux;
311	shift = mix->reg_info.shift_mux;
312
313	mux_val = MMP_CLK_BITS_GET_VAL(mux_div, width, shift);
314
315	return _get_mux(mix, mux_val);
316}
317
318static unsigned long mmp_clk_mix_recalc_rate(struct clk_hw *hw,
319					unsigned long parent_rate)
320{
321	struct mmp_clk_mix *mix = to_clk_mix(hw);
322	struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
323	unsigned long flags = 0;
324	u32 mux_div = 0;
325	u8 width, shift;
326	unsigned int div;
327
328	if (mix->lock)
329		spin_lock_irqsave(mix->lock, flags);
330
331	if (mix->type == MMP_CLK_MIX_TYPE_V1
332		|| mix->type == MMP_CLK_MIX_TYPE_V2)
333		mux_div = readl(ri->reg_clk_ctrl);
334	else
335		mux_div = readl(ri->reg_clk_sel);
336
337	if (mix->lock)
338		spin_unlock_irqrestore(mix->lock, flags);
339
340	width = mix->reg_info.width_div;
341	shift = mix->reg_info.shift_div;
342
343	div = _get_div(mix, MMP_CLK_BITS_GET_VAL(mux_div, width, shift));
344
345	return parent_rate / div;
346}
347
348static int mmp_clk_set_parent(struct clk_hw *hw, u8 index)
349{
350	struct mmp_clk_mix *mix = to_clk_mix(hw);
351	struct mmp_clk_mix_clk_table *item;
352	int i;
353	u32 div_val, mux_val;
354
355	if (mix->table) {
356		for (i = 0; i < mix->table_size; i++) {
357			item = &mix->table[i];
358			if (item->valid == 0)
359				continue;
360			if (item->parent_index == index)
361				break;
362		}
363		if (i < mix->table_size) {
364			div_val = _get_div_val(mix, item->divisor);
365			mux_val = _get_mux_val(mix, item->parent_index);
366		} else
367			return -EINVAL;
368	} else {
369		mux_val = _get_mux_val(mix, index);
370		div_val = 0;
371	}
372
373	return _set_rate(mix, mux_val, div_val, 1, div_val ? 1 : 0);
374}
375
376static int mmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
377				unsigned long best_parent_rate)
378{
379	struct mmp_clk_mix *mix = to_clk_mix(hw);
380	struct mmp_clk_mix_clk_table *item;
381	unsigned long parent_rate;
382	unsigned int best_divisor;
383	struct clk_hw *parent;
384	int i;
385
386	best_divisor = best_parent_rate / rate;
387
388	if (mix->table) {
389		for (i = 0; i < mix->table_size; i++) {
390			item = &mix->table[i];
391			if (item->valid == 0)
392				continue;
393			parent = clk_hw_get_parent_by_index(hw,
394							item->parent_index);
395			parent_rate = clk_hw_get_rate(parent);
396			if (parent_rate == best_parent_rate
397				&& item->divisor == best_divisor)
398				break;
399		}
400		if (i < mix->table_size)
401			return _set_rate(mix,
402					_get_mux_val(mix, item->parent_index),
403					_get_div_val(mix, item->divisor),
404					1, 1);
405		else
406			return -EINVAL;
407	} else {
408		for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
409			parent = clk_hw_get_parent_by_index(hw, i);
410			parent_rate = clk_hw_get_rate(parent);
411			if (parent_rate == best_parent_rate)
412				break;
413		}
414		if (i < clk_hw_get_num_parents(hw))
415			return _set_rate(mix, _get_mux_val(mix, i),
416					_get_div_val(mix, best_divisor), 1, 1);
417		else
418			return -EINVAL;
419	}
420}
421
422static void mmp_clk_mix_init(struct clk_hw *hw)
423{
424	struct mmp_clk_mix *mix = to_clk_mix(hw);
425
426	if (mix->table)
427		_filter_clk_table(mix, mix->table, mix->table_size);
428}
429
430const struct clk_ops mmp_clk_mix_ops = {
431	.determine_rate = mmp_clk_mix_determine_rate,
432	.set_rate_and_parent = mmp_clk_mix_set_rate_and_parent,
433	.set_rate = mmp_clk_set_rate,
434	.set_parent = mmp_clk_set_parent,
435	.get_parent = mmp_clk_mix_get_parent,
436	.recalc_rate = mmp_clk_mix_recalc_rate,
437	.init = mmp_clk_mix_init,
438};
439
440struct clk *mmp_clk_register_mix(struct device *dev,
441					const char *name,
442					const char **parent_names,
443					u8 num_parents,
444					unsigned long flags,
445					struct mmp_clk_mix_config *config,
446					spinlock_t *lock)
447{
448	struct mmp_clk_mix *mix;
449	struct clk *clk;
450	struct clk_init_data init;
451	size_t table_bytes;
452
453	mix = kzalloc(sizeof(*mix), GFP_KERNEL);
454	if (!mix) {
455		pr_err("%s:%s: could not allocate mmp mix clk\n",
456			__func__, name);
457		return ERR_PTR(-ENOMEM);
458	}
459
460	init.name = name;
461	init.flags = flags | CLK_GET_RATE_NOCACHE;
462	init.parent_names = parent_names;
463	init.num_parents = num_parents;
464	init.ops = &mmp_clk_mix_ops;
465
466	memcpy(&mix->reg_info, &config->reg_info, sizeof(config->reg_info));
467	if (config->table) {
468		table_bytes = sizeof(*config->table) * config->table_size;
469		mix->table = kmemdup(config->table, table_bytes, GFP_KERNEL);
470		if (!mix->table) {
471			pr_err("%s:%s: could not allocate mmp mix table\n",
472				__func__, name);
473			kfree(mix);
474			return ERR_PTR(-ENOMEM);
475		}
476		mix->table_size = config->table_size;
477	}
478
479	if (config->mux_table) {
480		table_bytes = sizeof(u32) * num_parents;
481		mix->mux_table = kmemdup(config->mux_table, table_bytes,
482					 GFP_KERNEL);
483		if (!mix->mux_table) {
484			pr_err("%s:%s: could not allocate mmp mix mux-table\n",
485				__func__, name);
486			kfree(mix->table);
487			kfree(mix);
488			return ERR_PTR(-ENOMEM);
489		}
490	}
491
492	mix->div_flags = config->div_flags;
493	mix->mux_flags = config->mux_flags;
494	mix->lock = lock;
495	mix->hw.init = &init;
496
497	if (config->reg_info.bit_fc >= 32)
498		mix->type = MMP_CLK_MIX_TYPE_V1;
499	else if (config->reg_info.reg_clk_sel)
500		mix->type = MMP_CLK_MIX_TYPE_V3;
501	else
502		mix->type = MMP_CLK_MIX_TYPE_V2;
503	clk = clk_register(dev, &mix->hw);
504
505	if (IS_ERR(clk)) {
506		kfree(mix->mux_table);
507		kfree(mix->table);
508		kfree(mix);
509	}
510
511	return clk;
512}
513