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v3.5.6
  1/*
  2 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
  3 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
  4 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 *
 10 * Adjustable divider clock implementation
 11 */
 12
 13#include <linux/clk-provider.h>
 14#include <linux/module.h>
 15#include <linux/slab.h>
 16#include <linux/io.h>
 17#include <linux/err.h>
 18#include <linux/string.h>
 
 19
 20/*
 21 * DOC: basic adjustable divider clock that cannot gate
 22 *
 23 * Traits of this clock:
 24 * prepare - clk_prepare only ensures that parents are prepared
 25 * enable - clk_enable only ensures that parents are enabled
 26 * rate - rate is adjustable.  clk->rate = parent->rate / divisor
 27 * parent - fixed parent.  No clk_set_parent support
 28 */
 29
 30#define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 31
 32#define div_mask(d)	((1 << (d->width)) - 1)
 
 
 
 
 
 
 
 
 
 
 33
 34static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
 35		unsigned long parent_rate)
 36{
 37	struct clk_divider *divider = to_clk_divider(hw);
 38	unsigned int div;
 
 
 
 39
 40	div = readl(divider->reg) >> divider->shift;
 41	div &= div_mask(divider);
 
 42
 43	if (!(divider->flags & CLK_DIVIDER_ONE_BASED))
 44		div++;
 
 
 45
 46	return parent_rate / div;
 
 
 
 47}
 48
 49/*
 50 * The reverse of DIV_ROUND_UP: The maximum number which
 51 * divided by m is r
 52 */
 53#define MULT_ROUND_UP(r, m) ((r) * (m) + (m) - 1)
 
 
 
 
 54
 55static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
 56		unsigned long *best_parent_rate)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 57{
 58	struct clk_divider *divider = to_clk_divider(hw);
 59	int i, bestdiv = 0;
 60	unsigned long parent_rate, best = 0, now, maxdiv;
 
 61
 62	if (!rate)
 63		rate = 1;
 64
 65	maxdiv = (1 << divider->width);
 66
 67	if (divider->flags & CLK_DIVIDER_ONE_BASED)
 68		maxdiv--;
 69
 70	if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) {
 71		parent_rate = *best_parent_rate;
 72		bestdiv = DIV_ROUND_UP(parent_rate, rate);
 73		bestdiv = bestdiv == 0 ? 1 : bestdiv;
 74		bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
 75		return bestdiv;
 76	}
 77
 78	/*
 79	 * The maximum divider we can use without overflowing
 80	 * unsigned long in rate * i below
 81	 */
 82	maxdiv = min(ULONG_MAX / rate, maxdiv);
 83
 84	for (i = 1; i <= maxdiv; i++) {
 85		parent_rate = __clk_round_rate(__clk_get_parent(hw->clk),
 86				MULT_ROUND_UP(rate, i));
 87		now = parent_rate / i;
 88		if (now <= rate && now > best) {
 
 
 
 
 
 
 
 
 
 89			bestdiv = i;
 90			best = now;
 91			*best_parent_rate = parent_rate;
 92		}
 93	}
 94
 95	if (!bestdiv) {
 96		bestdiv = (1 << divider->width);
 97		if (divider->flags & CLK_DIVIDER_ONE_BASED)
 98			bestdiv--;
 99		*best_parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), 1);
100	}
101
102	return bestdiv;
103}
104
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
105static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
106				unsigned long *prate)
107{
108	int div;
109	div = clk_divider_bestdiv(hw, rate, prate);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
110
111	return *prate / div;
 
 
 
 
 
112}
 
113
114static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
115				unsigned long parent_rate)
116{
117	struct clk_divider *divider = to_clk_divider(hw);
118	unsigned int div;
119	unsigned long flags = 0;
120	u32 val;
121
122	div = parent_rate / rate;
123
124	if (!(divider->flags & CLK_DIVIDER_ONE_BASED))
125		div--;
126
127	if (div > div_mask(divider))
128		div = div_mask(divider);
129
130	if (divider->lock)
131		spin_lock_irqsave(divider->lock, flags);
 
 
132
133	val = readl(divider->reg);
134	val &= ~(div_mask(divider) << divider->shift);
135	val |= div << divider->shift;
136	writel(val, divider->reg);
 
 
 
 
137
138	if (divider->lock)
139		spin_unlock_irqrestore(divider->lock, flags);
 
 
140
141	return 0;
142}
143
144const struct clk_ops clk_divider_ops = {
145	.recalc_rate = clk_divider_recalc_rate,
146	.round_rate = clk_divider_round_rate,
147	.set_rate = clk_divider_set_rate,
148};
149EXPORT_SYMBOL_GPL(clk_divider_ops);
150
151/**
152 * clk_register_divider - register a divider clock with the clock framework
153 * @dev: device registering this clock
154 * @name: name of this clock
155 * @parent_name: name of clock's parent
156 * @flags: framework-specific flags
157 * @reg: register address to adjust divider
158 * @shift: number of bits to shift the bitfield
159 * @width: width of the bitfield
160 * @clk_divider_flags: divider-specific flags for this clock
161 * @lock: shared register lock for this clock
162 */
163struct clk *clk_register_divider(struct device *dev, const char *name,
164		const char *parent_name, unsigned long flags,
165		void __iomem *reg, u8 shift, u8 width,
166		u8 clk_divider_flags, spinlock_t *lock)
 
167{
168	struct clk_divider *div;
169	struct clk *clk;
170	struct clk_init_data init;
 
 
 
 
 
 
 
 
171
172	/* allocate the divider */
173	div = kzalloc(sizeof(struct clk_divider), GFP_KERNEL);
174	if (!div) {
175		pr_err("%s: could not allocate divider clk\n", __func__);
176		return ERR_PTR(-ENOMEM);
177	}
178
179	init.name = name;
180	init.ops = &clk_divider_ops;
181	init.flags = flags;
 
 
 
182	init.parent_names = (parent_name ? &parent_name: NULL);
183	init.num_parents = (parent_name ? 1 : 0);
184
185	/* struct clk_divider assignments */
186	div->reg = reg;
187	div->shift = shift;
188	div->width = width;
189	div->flags = clk_divider_flags;
190	div->lock = lock;
191	div->hw.init = &init;
 
192
193	/* register the clock */
194	clk = clk_register(dev, &div->hw);
195
196	if (IS_ERR(clk))
197		kfree(div);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
198
199	return clk;
 
200}
v4.17
  1/*
  2 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
  3 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
  4 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 *
 10 * Adjustable divider clock implementation
 11 */
 12
 13#include <linux/clk-provider.h>
 14#include <linux/module.h>
 15#include <linux/slab.h>
 16#include <linux/io.h>
 17#include <linux/err.h>
 18#include <linux/string.h>
 19#include <linux/log2.h>
 20
 21/*
 22 * DOC: basic adjustable divider clock that cannot gate
 23 *
 24 * Traits of this clock:
 25 * prepare - clk_prepare only ensures that parents are prepared
 26 * enable - clk_enable only ensures that parents are enabled
 27 * rate - rate is adjustable.  clk->rate = ceiling(parent->rate / divisor)
 28 * parent - fixed parent.  No clk_set_parent support
 29 */
 30
 31static unsigned int _get_table_maxdiv(const struct clk_div_table *table,
 32				      u8 width)
 33{
 34	unsigned int maxdiv = 0, mask = clk_div_mask(width);
 35	const struct clk_div_table *clkt;
 36
 37	for (clkt = table; clkt->div; clkt++)
 38		if (clkt->div > maxdiv && clkt->val <= mask)
 39			maxdiv = clkt->div;
 40	return maxdiv;
 41}
 42
 43static unsigned int _get_table_mindiv(const struct clk_div_table *table)
 44{
 45	unsigned int mindiv = UINT_MAX;
 46	const struct clk_div_table *clkt;
 47
 48	for (clkt = table; clkt->div; clkt++)
 49		if (clkt->div < mindiv)
 50			mindiv = clkt->div;
 51	return mindiv;
 52}
 53
 54static unsigned int _get_maxdiv(const struct clk_div_table *table, u8 width,
 55				unsigned long flags)
 56{
 57	if (flags & CLK_DIVIDER_ONE_BASED)
 58		return clk_div_mask(width);
 59	if (flags & CLK_DIVIDER_POWER_OF_TWO)
 60		return 1 << clk_div_mask(width);
 61	if (table)
 62		return _get_table_maxdiv(table, width);
 63	return clk_div_mask(width) + 1;
 64}
 65
 66static unsigned int _get_table_div(const struct clk_div_table *table,
 67							unsigned int val)
 68{
 69	const struct clk_div_table *clkt;
 70
 71	for (clkt = table; clkt->div; clkt++)
 72		if (clkt->val == val)
 73			return clkt->div;
 74	return 0;
 75}
 76
 77static unsigned int _get_div(const struct clk_div_table *table,
 78			     unsigned int val, unsigned long flags, u8 width)
 79{
 80	if (flags & CLK_DIVIDER_ONE_BASED)
 81		return val;
 82	if (flags & CLK_DIVIDER_POWER_OF_TWO)
 83		return 1 << val;
 84	if (flags & CLK_DIVIDER_MAX_AT_ZERO)
 85		return val ? val : clk_div_mask(width) + 1;
 86	if (table)
 87		return _get_table_div(table, val);
 88	return val + 1;
 89}
 90
 91static unsigned int _get_table_val(const struct clk_div_table *table,
 92							unsigned int div)
 93{
 94	const struct clk_div_table *clkt;
 95
 96	for (clkt = table; clkt->div; clkt++)
 97		if (clkt->div == div)
 98			return clkt->val;
 99	return 0;
100}
101
102static unsigned int _get_val(const struct clk_div_table *table,
103			     unsigned int div, unsigned long flags, u8 width)
104{
105	if (flags & CLK_DIVIDER_ONE_BASED)
106		return div;
107	if (flags & CLK_DIVIDER_POWER_OF_TWO)
108		return __ffs(div);
109	if (flags & CLK_DIVIDER_MAX_AT_ZERO)
110		return (div == clk_div_mask(width) + 1) ? 0 : div;
111	if (table)
112		return  _get_table_val(table, div);
113	return div - 1;
114}
115
116unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate,
117				  unsigned int val,
118				  const struct clk_div_table *table,
119				  unsigned long flags, unsigned long width)
120{
121	unsigned int div;
122
123	div = _get_div(table, val, flags, width);
124	if (!div) {
125		WARN(!(flags & CLK_DIVIDER_ALLOW_ZERO),
126			"%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
127			clk_hw_get_name(hw));
128		return parent_rate;
129	}
130
131	return DIV_ROUND_UP_ULL((u64)parent_rate, div);
132}
133EXPORT_SYMBOL_GPL(divider_recalc_rate);
134
135static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
136		unsigned long parent_rate)
137{
138	struct clk_divider *divider = to_clk_divider(hw);
139	unsigned int val;
140
141	val = clk_readl(divider->reg) >> divider->shift;
142	val &= clk_div_mask(divider->width);
143
144	return divider_recalc_rate(hw, parent_rate, val, divider->table,
145				   divider->flags, divider->width);
146}
147
148static bool _is_valid_table_div(const struct clk_div_table *table,
149							 unsigned int div)
150{
151	const struct clk_div_table *clkt;
152
153	for (clkt = table; clkt->div; clkt++)
154		if (clkt->div == div)
155			return true;
156	return false;
157}
158
159static bool _is_valid_div(const struct clk_div_table *table, unsigned int div,
160			  unsigned long flags)
161{
162	if (flags & CLK_DIVIDER_POWER_OF_TWO)
163		return is_power_of_2(div);
164	if (table)
165		return _is_valid_table_div(table, div);
166	return true;
167}
168
169static int _round_up_table(const struct clk_div_table *table, int div)
170{
171	const struct clk_div_table *clkt;
172	int up = INT_MAX;
173
174	for (clkt = table; clkt->div; clkt++) {
175		if (clkt->div == div)
176			return clkt->div;
177		else if (clkt->div < div)
178			continue;
179
180		if ((clkt->div - div) < (up - div))
181			up = clkt->div;
182	}
183
184	return up;
185}
186
187static int _round_down_table(const struct clk_div_table *table, int div)
188{
189	const struct clk_div_table *clkt;
190	int down = _get_table_mindiv(table);
191
192	for (clkt = table; clkt->div; clkt++) {
193		if (clkt->div == div)
194			return clkt->div;
195		else if (clkt->div > div)
196			continue;
197
198		if ((div - clkt->div) < (div - down))
199			down = clkt->div;
200	}
201
202	return down;
203}
204
205static int _div_round_up(const struct clk_div_table *table,
206			 unsigned long parent_rate, unsigned long rate,
207			 unsigned long flags)
208{
209	int div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
210
211	if (flags & CLK_DIVIDER_POWER_OF_TWO)
212		div = __roundup_pow_of_two(div);
213	if (table)
214		div = _round_up_table(table, div);
215
216	return div;
217}
218
219static int _div_round_closest(const struct clk_div_table *table,
220			      unsigned long parent_rate, unsigned long rate,
221			      unsigned long flags)
222{
223	int up, down;
224	unsigned long up_rate, down_rate;
225
226	up = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
227	down = parent_rate / rate;
228
229	if (flags & CLK_DIVIDER_POWER_OF_TWO) {
230		up = __roundup_pow_of_two(up);
231		down = __rounddown_pow_of_two(down);
232	} else if (table) {
233		up = _round_up_table(table, up);
234		down = _round_down_table(table, down);
235	}
236
237	up_rate = DIV_ROUND_UP_ULL((u64)parent_rate, up);
238	down_rate = DIV_ROUND_UP_ULL((u64)parent_rate, down);
239
240	return (rate - up_rate) <= (down_rate - rate) ? up : down;
241}
242
243static int _div_round(const struct clk_div_table *table,
244		      unsigned long parent_rate, unsigned long rate,
245		      unsigned long flags)
246{
247	if (flags & CLK_DIVIDER_ROUND_CLOSEST)
248		return _div_round_closest(table, parent_rate, rate, flags);
249
250	return _div_round_up(table, parent_rate, rate, flags);
251}
252
253static bool _is_best_div(unsigned long rate, unsigned long now,
254			 unsigned long best, unsigned long flags)
255{
256	if (flags & CLK_DIVIDER_ROUND_CLOSEST)
257		return abs(rate - now) < abs(rate - best);
258
259	return now <= rate && now > best;
260}
261
262static int _next_div(const struct clk_div_table *table, int div,
263		     unsigned long flags)
264{
265	div++;
266
267	if (flags & CLK_DIVIDER_POWER_OF_TWO)
268		return __roundup_pow_of_two(div);
269	if (table)
270		return _round_up_table(table, div);
271
272	return div;
273}
274
275static int clk_divider_bestdiv(struct clk_hw *hw, struct clk_hw *parent,
276			       unsigned long rate,
277			       unsigned long *best_parent_rate,
278			       const struct clk_div_table *table, u8 width,
279			       unsigned long flags)
280{
 
281	int i, bestdiv = 0;
282	unsigned long parent_rate, best = 0, now, maxdiv;
283	unsigned long parent_rate_saved = *best_parent_rate;
284
285	if (!rate)
286		rate = 1;
287
288	maxdiv = _get_maxdiv(table, width, flags);
 
 
 
289
290	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
291		parent_rate = *best_parent_rate;
292		bestdiv = _div_round(table, parent_rate, rate, flags);
293		bestdiv = bestdiv == 0 ? 1 : bestdiv;
294		bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
295		return bestdiv;
296	}
297
298	/*
299	 * The maximum divider we can use without overflowing
300	 * unsigned long in rate * i below
301	 */
302	maxdiv = min(ULONG_MAX / rate, maxdiv);
303
304	for (i = _next_div(table, 0, flags); i <= maxdiv;
305					     i = _next_div(table, i, flags)) {
306		if (rate * i == parent_rate_saved) {
307			/*
308			 * It's the most ideal case if the requested rate can be
309			 * divided from parent clock without needing to change
310			 * parent rate, so return the divider immediately.
311			 */
312			*best_parent_rate = parent_rate_saved;
313			return i;
314		}
315		parent_rate = clk_hw_round_rate(parent, rate * i);
316		now = DIV_ROUND_UP_ULL((u64)parent_rate, i);
317		if (_is_best_div(rate, now, best, flags)) {
318			bestdiv = i;
319			best = now;
320			*best_parent_rate = parent_rate;
321		}
322	}
323
324	if (!bestdiv) {
325		bestdiv = _get_maxdiv(table, width, flags);
326		*best_parent_rate = clk_hw_round_rate(parent, 1);
 
 
327	}
328
329	return bestdiv;
330}
331
332long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
333			       unsigned long rate, unsigned long *prate,
334			       const struct clk_div_table *table,
335			       u8 width, unsigned long flags)
336{
337	int div;
338
339	div = clk_divider_bestdiv(hw, parent, rate, prate, table, width, flags);
340
341	return DIV_ROUND_UP_ULL((u64)*prate, div);
342}
343EXPORT_SYMBOL_GPL(divider_round_rate_parent);
344
345long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
346				  unsigned long rate, unsigned long *prate,
347				  const struct clk_div_table *table, u8 width,
348				  unsigned long flags, unsigned int val)
349{
350	int div;
351
352	div = _get_div(table, val, flags, width);
353
354	/* Even a read-only clock can propagate a rate change */
355	if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
356		if (!parent)
357			return -EINVAL;
358
359		*prate = clk_hw_round_rate(parent, rate * div);
360	}
361
362	return DIV_ROUND_UP_ULL((u64)*prate, div);
363}
364EXPORT_SYMBOL_GPL(divider_ro_round_rate_parent);
365
366
367static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
368				unsigned long *prate)
369{
370	struct clk_divider *divider = to_clk_divider(hw);
371
372	/* if read only, just return current value */
373	if (divider->flags & CLK_DIVIDER_READ_ONLY) {
374		u32 val;
375
376		val = clk_readl(divider->reg) >> divider->shift;
377		val &= clk_div_mask(divider->width);
378
379		return divider_ro_round_rate(hw, rate, prate, divider->table,
380					     divider->width, divider->flags,
381					     val);
382	}
383
384	return divider_round_rate(hw, rate, prate, divider->table,
385				  divider->width, divider->flags);
386}
387
388int divider_get_val(unsigned long rate, unsigned long parent_rate,
389		    const struct clk_div_table *table, u8 width,
390		    unsigned long flags)
391{
392	unsigned int div, value;
393
394	div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
395
396	if (!_is_valid_div(table, div, flags))
397		return -EINVAL;
398
399	value = _get_val(table, div, flags, width);
400
401	return min_t(unsigned int, value, clk_div_mask(width));
402}
403EXPORT_SYMBOL_GPL(divider_get_val);
404
405static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
406				unsigned long parent_rate)
407{
408	struct clk_divider *divider = to_clk_divider(hw);
409	int value;
410	unsigned long flags = 0;
411	u32 val;
412
413	value = divider_get_val(rate, parent_rate, divider->table,
414				divider->width, divider->flags);
415	if (value < 0)
416		return value;
 
 
 
417
418	if (divider->lock)
419		spin_lock_irqsave(divider->lock, flags);
420	else
421		__acquire(divider->lock);
422
423	if (divider->flags & CLK_DIVIDER_HIWORD_MASK) {
424		val = clk_div_mask(divider->width) << (divider->shift + 16);
425	} else {
426		val = clk_readl(divider->reg);
427		val &= ~(clk_div_mask(divider->width) << divider->shift);
428	}
429	val |= (u32)value << divider->shift;
430	clk_writel(val, divider->reg);
431
432	if (divider->lock)
433		spin_unlock_irqrestore(divider->lock, flags);
434	else
435		__release(divider->lock);
436
437	return 0;
438}
439
440const struct clk_ops clk_divider_ops = {
441	.recalc_rate = clk_divider_recalc_rate,
442	.round_rate = clk_divider_round_rate,
443	.set_rate = clk_divider_set_rate,
444};
445EXPORT_SYMBOL_GPL(clk_divider_ops);
446
447const struct clk_ops clk_divider_ro_ops = {
448	.recalc_rate = clk_divider_recalc_rate,
449	.round_rate = clk_divider_round_rate,
450};
451EXPORT_SYMBOL_GPL(clk_divider_ro_ops);
452
453static struct clk_hw *_register_divider(struct device *dev, const char *name,
 
 
 
 
 
 
454		const char *parent_name, unsigned long flags,
455		void __iomem *reg, u8 shift, u8 width,
456		u8 clk_divider_flags, const struct clk_div_table *table,
457		spinlock_t *lock)
458{
459	struct clk_divider *div;
460	struct clk_hw *hw;
461	struct clk_init_data init;
462	int ret;
463
464	if (clk_divider_flags & CLK_DIVIDER_HIWORD_MASK) {
465		if (width + shift > 16) {
466			pr_warn("divider value exceeds LOWORD field\n");
467			return ERR_PTR(-EINVAL);
468		}
469	}
470
471	/* allocate the divider */
472	div = kzalloc(sizeof(*div), GFP_KERNEL);
473	if (!div)
 
474		return ERR_PTR(-ENOMEM);
 
475
476	init.name = name;
477	if (clk_divider_flags & CLK_DIVIDER_READ_ONLY)
478		init.ops = &clk_divider_ro_ops;
479	else
480		init.ops = &clk_divider_ops;
481	init.flags = flags | CLK_IS_BASIC;
482	init.parent_names = (parent_name ? &parent_name: NULL);
483	init.num_parents = (parent_name ? 1 : 0);
484
485	/* struct clk_divider assignments */
486	div->reg = reg;
487	div->shift = shift;
488	div->width = width;
489	div->flags = clk_divider_flags;
490	div->lock = lock;
491	div->hw.init = &init;
492	div->table = table;
493
494	/* register the clock */
495	hw = &div->hw;
496	ret = clk_hw_register(dev, hw);
497	if (ret) {
498		kfree(div);
499		hw = ERR_PTR(ret);
500	}
501
502	return hw;
503}
504
505/**
506 * clk_register_divider - register a divider clock with the clock framework
507 * @dev: device registering this clock
508 * @name: name of this clock
509 * @parent_name: name of clock's parent
510 * @flags: framework-specific flags
511 * @reg: register address to adjust divider
512 * @shift: number of bits to shift the bitfield
513 * @width: width of the bitfield
514 * @clk_divider_flags: divider-specific flags for this clock
515 * @lock: shared register lock for this clock
516 */
517struct clk *clk_register_divider(struct device *dev, const char *name,
518		const char *parent_name, unsigned long flags,
519		void __iomem *reg, u8 shift, u8 width,
520		u8 clk_divider_flags, spinlock_t *lock)
521{
522	struct clk_hw *hw;
523
524	hw =  _register_divider(dev, name, parent_name, flags, reg, shift,
525			width, clk_divider_flags, NULL, lock);
526	if (IS_ERR(hw))
527		return ERR_CAST(hw);
528	return hw->clk;
529}
530EXPORT_SYMBOL_GPL(clk_register_divider);
531
532/**
533 * clk_hw_register_divider - register a divider clock with the clock framework
534 * @dev: device registering this clock
535 * @name: name of this clock
536 * @parent_name: name of clock's parent
537 * @flags: framework-specific flags
538 * @reg: register address to adjust divider
539 * @shift: number of bits to shift the bitfield
540 * @width: width of the bitfield
541 * @clk_divider_flags: divider-specific flags for this clock
542 * @lock: shared register lock for this clock
543 */
544struct clk_hw *clk_hw_register_divider(struct device *dev, const char *name,
545		const char *parent_name, unsigned long flags,
546		void __iomem *reg, u8 shift, u8 width,
547		u8 clk_divider_flags, spinlock_t *lock)
548{
549	return _register_divider(dev, name, parent_name, flags, reg, shift,
550			width, clk_divider_flags, NULL, lock);
551}
552EXPORT_SYMBOL_GPL(clk_hw_register_divider);
553
554/**
555 * clk_register_divider_table - register a table based divider clock with
556 * the clock framework
557 * @dev: device registering this clock
558 * @name: name of this clock
559 * @parent_name: name of clock's parent
560 * @flags: framework-specific flags
561 * @reg: register address to adjust divider
562 * @shift: number of bits to shift the bitfield
563 * @width: width of the bitfield
564 * @clk_divider_flags: divider-specific flags for this clock
565 * @table: array of divider/value pairs ending with a div set to 0
566 * @lock: shared register lock for this clock
567 */
568struct clk *clk_register_divider_table(struct device *dev, const char *name,
569		const char *parent_name, unsigned long flags,
570		void __iomem *reg, u8 shift, u8 width,
571		u8 clk_divider_flags, const struct clk_div_table *table,
572		spinlock_t *lock)
573{
574	struct clk_hw *hw;
575
576	hw =  _register_divider(dev, name, parent_name, flags, reg, shift,
577			width, clk_divider_flags, table, lock);
578	if (IS_ERR(hw))
579		return ERR_CAST(hw);
580	return hw->clk;
581}
582EXPORT_SYMBOL_GPL(clk_register_divider_table);
583
584/**
585 * clk_hw_register_divider_table - register a table based divider clock with
586 * the clock framework
587 * @dev: device registering this clock
588 * @name: name of this clock
589 * @parent_name: name of clock's parent
590 * @flags: framework-specific flags
591 * @reg: register address to adjust divider
592 * @shift: number of bits to shift the bitfield
593 * @width: width of the bitfield
594 * @clk_divider_flags: divider-specific flags for this clock
595 * @table: array of divider/value pairs ending with a div set to 0
596 * @lock: shared register lock for this clock
597 */
598struct clk_hw *clk_hw_register_divider_table(struct device *dev,
599		const char *name, const char *parent_name, unsigned long flags,
600		void __iomem *reg, u8 shift, u8 width,
601		u8 clk_divider_flags, const struct clk_div_table *table,
602		spinlock_t *lock)
603{
604	return _register_divider(dev, name, parent_name, flags, reg, shift,
605			width, clk_divider_flags, table, lock);
606}
607EXPORT_SYMBOL_GPL(clk_hw_register_divider_table);
608
609void clk_unregister_divider(struct clk *clk)
610{
611	struct clk_divider *div;
612	struct clk_hw *hw;
613
614	hw = __clk_get_hw(clk);
615	if (!hw)
616		return;
617
618	div = to_clk_divider(hw);
619
620	clk_unregister(clk);
621	kfree(div);
622}
623EXPORT_SYMBOL_GPL(clk_unregister_divider);
624
625/**
626 * clk_hw_unregister_divider - unregister a clk divider
627 * @hw: hardware-specific clock data to unregister
628 */
629void clk_hw_unregister_divider(struct clk_hw *hw)
630{
631	struct clk_divider *div;
632
633	div = to_clk_divider(hw);
634
635	clk_hw_unregister(hw);
636	kfree(div);
637}
638EXPORT_SYMBOL_GPL(clk_hw_unregister_divider);