xref: /openbmc/linux/drivers/clk/ingenic/cgu.c (revision d47a97bd)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Ingenic SoC CGU driver
4  *
5  * Copyright (c) 2013-2015 Imagination Technologies
6  * Author: Paul Burton <paul.burton@mips.com>
7  */
8 
9 #include <linux/bitops.h>
10 #include <linux/clk.h>
11 #include <linux/clk-provider.h>
12 #include <linux/clkdev.h>
13 #include <linux/delay.h>
14 #include <linux/io.h>
15 #include <linux/iopoll.h>
16 #include <linux/math64.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 #include <linux/time.h>
22 
23 #include "cgu.h"
24 
25 #define MHZ (1000 * 1000)
26 
27 static inline const struct ingenic_cgu_clk_info *
28 to_clk_info(struct ingenic_clk *clk)
29 {
30 	return &clk->cgu->clock_info[clk->idx];
31 }
32 
33 /**
34  * ingenic_cgu_gate_get() - get the value of clock gate register bit
35  * @cgu: reference to the CGU whose registers should be read
36  * @info: info struct describing the gate bit
37  *
38  * Retrieves the state of the clock gate bit described by info. The
39  * caller must hold cgu->lock.
40  *
41  * Return: true if the gate bit is set, else false.
42  */
43 static inline bool
44 ingenic_cgu_gate_get(struct ingenic_cgu *cgu,
45 		     const struct ingenic_cgu_gate_info *info)
46 {
47 	return !!(readl(cgu->base + info->reg) & BIT(info->bit))
48 		^ info->clear_to_gate;
49 }
50 
51 /**
52  * ingenic_cgu_gate_set() - set the value of clock gate register bit
53  * @cgu: reference to the CGU whose registers should be modified
54  * @info: info struct describing the gate bit
55  * @val: non-zero to gate a clock, otherwise zero
56  *
57  * Sets the given gate bit in order to gate or ungate a clock.
58  *
59  * The caller must hold cgu->lock.
60  */
61 static inline void
62 ingenic_cgu_gate_set(struct ingenic_cgu *cgu,
63 		     const struct ingenic_cgu_gate_info *info, bool val)
64 {
65 	u32 clkgr = readl(cgu->base + info->reg);
66 
67 	if (val ^ info->clear_to_gate)
68 		clkgr |= BIT(info->bit);
69 	else
70 		clkgr &= ~BIT(info->bit);
71 
72 	writel(clkgr, cgu->base + info->reg);
73 }
74 
75 /*
76  * PLL operations
77  */
78 
79 static unsigned long
80 ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
81 {
82 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
83 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
84 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
85 	const struct ingenic_cgu_pll_info *pll_info;
86 	unsigned m, n, od, od_enc = 0;
87 	bool bypass;
88 	u32 ctl;
89 
90 	BUG_ON(clk_info->type != CGU_CLK_PLL);
91 	pll_info = &clk_info->pll;
92 
93 	ctl = readl(cgu->base + pll_info->reg);
94 
95 	m = (ctl >> pll_info->m_shift) & GENMASK(pll_info->m_bits - 1, 0);
96 	m += pll_info->m_offset;
97 	n = (ctl >> pll_info->n_shift) & GENMASK(pll_info->n_bits - 1, 0);
98 	n += pll_info->n_offset;
99 
100 	if (pll_info->od_bits > 0) {
101 		od_enc = ctl >> pll_info->od_shift;
102 		od_enc &= GENMASK(pll_info->od_bits - 1, 0);
103 	}
104 
105 	if (pll_info->bypass_bit >= 0) {
106 		ctl = readl(cgu->base + pll_info->bypass_reg);
107 
108 		bypass = !!(ctl & BIT(pll_info->bypass_bit));
109 
110 		if (bypass)
111 			return parent_rate;
112 	}
113 
114 	for (od = 0; od < pll_info->od_max; od++)
115 		if (pll_info->od_encoding[od] == od_enc)
116 			break;
117 
118 	/* if od_max = 0, od_bits should be 0 and od is fixed to 1. */
119 	if (pll_info->od_max == 0)
120 		BUG_ON(pll_info->od_bits != 0);
121 	else
122 		BUG_ON(od == pll_info->od_max);
123 	od++;
124 
125 	return div_u64((u64)parent_rate * m * pll_info->rate_multiplier,
126 		n * od);
127 }
128 
129 static void
130 ingenic_pll_calc_m_n_od(const struct ingenic_cgu_pll_info *pll_info,
131 			unsigned long rate, unsigned long parent_rate,
132 			unsigned int *pm, unsigned int *pn, unsigned int *pod)
133 {
134 	unsigned int m, n, od = 1;
135 
136 	/*
137 	 * The frequency after the input divider must be between 10 and 50 MHz.
138 	 * The highest divider yields the best resolution.
139 	 */
140 	n = parent_rate / (10 * MHZ);
141 	n = min_t(unsigned int, n, 1 << pll_info->n_bits);
142 	n = max_t(unsigned int, n, pll_info->n_offset);
143 
144 	m = (rate / MHZ) * od * n / (parent_rate / MHZ);
145 	m = min_t(unsigned int, m, 1 << pll_info->m_bits);
146 	m = max_t(unsigned int, m, pll_info->m_offset);
147 
148 	*pm = m;
149 	*pn = n;
150 	*pod = od;
151 }
152 
153 static unsigned long
154 ingenic_pll_calc(const struct ingenic_cgu_clk_info *clk_info,
155 		 unsigned long rate, unsigned long parent_rate,
156 		 unsigned int *pm, unsigned int *pn, unsigned int *pod)
157 {
158 	const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
159 	unsigned int m, n, od;
160 
161 	if (pll_info->calc_m_n_od)
162 		(*pll_info->calc_m_n_od)(pll_info, rate, parent_rate, &m, &n, &od);
163 	else
164 		ingenic_pll_calc_m_n_od(pll_info, rate, parent_rate, &m, &n, &od);
165 
166 	if (pm)
167 		*pm = m;
168 	if (pn)
169 		*pn = n;
170 	if (pod)
171 		*pod = od;
172 
173 	return div_u64((u64)parent_rate * m * pll_info->rate_multiplier,
174 		n * od);
175 }
176 
177 static long
178 ingenic_pll_round_rate(struct clk_hw *hw, unsigned long req_rate,
179 		       unsigned long *prate)
180 {
181 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
182 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
183 
184 	return ingenic_pll_calc(clk_info, req_rate, *prate, NULL, NULL, NULL);
185 }
186 
187 static inline int ingenic_pll_check_stable(struct ingenic_cgu *cgu,
188 					   const struct ingenic_cgu_pll_info *pll_info)
189 {
190 	u32 ctl;
191 
192 	if (pll_info->stable_bit < 0)
193 		return 0;
194 
195 	return readl_poll_timeout(cgu->base + pll_info->reg, ctl,
196 				  ctl & BIT(pll_info->stable_bit),
197 				  0, 100 * USEC_PER_MSEC);
198 }
199 
200 static int
201 ingenic_pll_set_rate(struct clk_hw *hw, unsigned long req_rate,
202 		     unsigned long parent_rate)
203 {
204 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
205 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
206 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
207 	const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
208 	unsigned long rate, flags;
209 	unsigned int m, n, od;
210 	int ret = 0;
211 	u32 ctl;
212 
213 	rate = ingenic_pll_calc(clk_info, req_rate, parent_rate,
214 			       &m, &n, &od);
215 	if (rate != req_rate)
216 		pr_info("ingenic-cgu: request '%s' rate %luHz, actual %luHz\n",
217 			clk_info->name, req_rate, rate);
218 
219 	spin_lock_irqsave(&cgu->lock, flags);
220 	ctl = readl(cgu->base + pll_info->reg);
221 
222 	ctl &= ~(GENMASK(pll_info->m_bits - 1, 0) << pll_info->m_shift);
223 	ctl |= (m - pll_info->m_offset) << pll_info->m_shift;
224 
225 	ctl &= ~(GENMASK(pll_info->n_bits - 1, 0) << pll_info->n_shift);
226 	ctl |= (n - pll_info->n_offset) << pll_info->n_shift;
227 
228 	if (pll_info->od_bits > 0) {
229 		ctl &= ~(GENMASK(pll_info->od_bits - 1, 0) << pll_info->od_shift);
230 		ctl |= pll_info->od_encoding[od - 1] << pll_info->od_shift;
231 	}
232 
233 	writel(ctl, cgu->base + pll_info->reg);
234 
235 	if (pll_info->set_rate_hook)
236 		pll_info->set_rate_hook(pll_info, rate, parent_rate);
237 
238 	/* If the PLL is enabled, verify that it's stable */
239 	if (pll_info->enable_bit >= 0 && (ctl & BIT(pll_info->enable_bit)))
240 		ret = ingenic_pll_check_stable(cgu, pll_info);
241 
242 	spin_unlock_irqrestore(&cgu->lock, flags);
243 
244 	return ret;
245 }
246 
247 static int ingenic_pll_enable(struct clk_hw *hw)
248 {
249 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
250 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
251 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
252 	const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
253 	unsigned long flags;
254 	int ret;
255 	u32 ctl;
256 
257 	if (pll_info->enable_bit < 0)
258 		return 0;
259 
260 	spin_lock_irqsave(&cgu->lock, flags);
261 	if (pll_info->bypass_bit >= 0) {
262 		ctl = readl(cgu->base + pll_info->bypass_reg);
263 
264 		ctl &= ~BIT(pll_info->bypass_bit);
265 
266 		writel(ctl, cgu->base + pll_info->bypass_reg);
267 	}
268 
269 	ctl = readl(cgu->base + pll_info->reg);
270 
271 	ctl |= BIT(pll_info->enable_bit);
272 
273 	writel(ctl, cgu->base + pll_info->reg);
274 
275 	ret = ingenic_pll_check_stable(cgu, pll_info);
276 	spin_unlock_irqrestore(&cgu->lock, flags);
277 
278 	return ret;
279 }
280 
281 static void ingenic_pll_disable(struct clk_hw *hw)
282 {
283 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
284 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
285 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
286 	const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
287 	unsigned long flags;
288 	u32 ctl;
289 
290 	if (pll_info->enable_bit < 0)
291 		return;
292 
293 	spin_lock_irqsave(&cgu->lock, flags);
294 	ctl = readl(cgu->base + pll_info->reg);
295 
296 	ctl &= ~BIT(pll_info->enable_bit);
297 
298 	writel(ctl, cgu->base + pll_info->reg);
299 	spin_unlock_irqrestore(&cgu->lock, flags);
300 }
301 
302 static int ingenic_pll_is_enabled(struct clk_hw *hw)
303 {
304 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
305 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
306 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
307 	const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
308 	u32 ctl;
309 
310 	if (pll_info->enable_bit < 0)
311 		return true;
312 
313 	ctl = readl(cgu->base + pll_info->reg);
314 
315 	return !!(ctl & BIT(pll_info->enable_bit));
316 }
317 
318 static const struct clk_ops ingenic_pll_ops = {
319 	.recalc_rate = ingenic_pll_recalc_rate,
320 	.round_rate = ingenic_pll_round_rate,
321 	.set_rate = ingenic_pll_set_rate,
322 
323 	.enable = ingenic_pll_enable,
324 	.disable = ingenic_pll_disable,
325 	.is_enabled = ingenic_pll_is_enabled,
326 };
327 
328 /*
329  * Operations for all non-PLL clocks
330  */
331 
332 static u8 ingenic_clk_get_parent(struct clk_hw *hw)
333 {
334 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
335 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
336 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
337 	u32 reg;
338 	u8 i, hw_idx, idx = 0;
339 
340 	if (clk_info->type & CGU_CLK_MUX) {
341 		reg = readl(cgu->base + clk_info->mux.reg);
342 		hw_idx = (reg >> clk_info->mux.shift) &
343 			 GENMASK(clk_info->mux.bits - 1, 0);
344 
345 		/*
346 		 * Convert the hardware index to the parent index by skipping
347 		 * over any -1's in the parents array.
348 		 */
349 		for (i = 0; i < hw_idx; i++) {
350 			if (clk_info->parents[i] != -1)
351 				idx++;
352 		}
353 	}
354 
355 	return idx;
356 }
357 
358 static int ingenic_clk_set_parent(struct clk_hw *hw, u8 idx)
359 {
360 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
361 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
362 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
363 	unsigned long flags;
364 	u8 curr_idx, hw_idx, num_poss;
365 	u32 reg, mask;
366 
367 	if (clk_info->type & CGU_CLK_MUX) {
368 		/*
369 		 * Convert the parent index to the hardware index by adding
370 		 * 1 for any -1 in the parents array preceding the given
371 		 * index. That is, we want the index of idx'th entry in
372 		 * clk_info->parents which does not equal -1.
373 		 */
374 		hw_idx = curr_idx = 0;
375 		num_poss = 1 << clk_info->mux.bits;
376 		for (; hw_idx < num_poss; hw_idx++) {
377 			if (clk_info->parents[hw_idx] == -1)
378 				continue;
379 			if (curr_idx == idx)
380 				break;
381 			curr_idx++;
382 		}
383 
384 		/* idx should always be a valid parent */
385 		BUG_ON(curr_idx != idx);
386 
387 		mask = GENMASK(clk_info->mux.bits - 1, 0);
388 		mask <<= clk_info->mux.shift;
389 
390 		spin_lock_irqsave(&cgu->lock, flags);
391 
392 		/* write the register */
393 		reg = readl(cgu->base + clk_info->mux.reg);
394 		reg &= ~mask;
395 		reg |= hw_idx << clk_info->mux.shift;
396 		writel(reg, cgu->base + clk_info->mux.reg);
397 
398 		spin_unlock_irqrestore(&cgu->lock, flags);
399 		return 0;
400 	}
401 
402 	return idx ? -EINVAL : 0;
403 }
404 
405 static unsigned long
406 ingenic_clk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
407 {
408 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
409 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
410 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
411 	unsigned long rate = parent_rate;
412 	u32 div_reg, div;
413 	u8 parent;
414 
415 	if (clk_info->type & CGU_CLK_DIV) {
416 		parent = ingenic_clk_get_parent(hw);
417 
418 		if (!(clk_info->div.bypass_mask & BIT(parent))) {
419 			div_reg = readl(cgu->base + clk_info->div.reg);
420 			div = (div_reg >> clk_info->div.shift) &
421 			      GENMASK(clk_info->div.bits - 1, 0);
422 
423 			if (clk_info->div.div_table)
424 				div = clk_info->div.div_table[div];
425 			else
426 				div = (div + 1) * clk_info->div.div;
427 
428 			rate /= div;
429 		}
430 	} else if (clk_info->type & CGU_CLK_FIXDIV) {
431 		rate /= clk_info->fixdiv.div;
432 	}
433 
434 	return rate;
435 }
436 
437 static unsigned int
438 ingenic_clk_calc_hw_div(const struct ingenic_cgu_clk_info *clk_info,
439 			unsigned int div)
440 {
441 	unsigned int i, best_i = 0, best = (unsigned int)-1;
442 
443 	for (i = 0; i < (1 << clk_info->div.bits)
444 				&& clk_info->div.div_table[i]; i++) {
445 		if (clk_info->div.div_table[i] >= div &&
446 		    clk_info->div.div_table[i] < best) {
447 			best = clk_info->div.div_table[i];
448 			best_i = i;
449 
450 			if (div == best)
451 				break;
452 		}
453 	}
454 
455 	return best_i;
456 }
457 
458 static unsigned
459 ingenic_clk_calc_div(struct clk_hw *hw,
460 		     const struct ingenic_cgu_clk_info *clk_info,
461 		     unsigned long parent_rate, unsigned long req_rate)
462 {
463 	unsigned int div, hw_div;
464 	u8 parent;
465 
466 	parent = ingenic_clk_get_parent(hw);
467 	if (clk_info->div.bypass_mask & BIT(parent))
468 		return 1;
469 
470 	/* calculate the divide */
471 	div = DIV_ROUND_UP(parent_rate, req_rate);
472 
473 	if (clk_info->div.div_table) {
474 		hw_div = ingenic_clk_calc_hw_div(clk_info, div);
475 
476 		return clk_info->div.div_table[hw_div];
477 	}
478 
479 	/* Impose hardware constraints */
480 	div = clamp_t(unsigned int, div, clk_info->div.div,
481 		      clk_info->div.div << clk_info->div.bits);
482 
483 	/*
484 	 * If the divider value itself must be divided before being written to
485 	 * the divider register, we must ensure we don't have any bits set that
486 	 * would be lost as a result of doing so.
487 	 */
488 	div = DIV_ROUND_UP(div, clk_info->div.div);
489 	div *= clk_info->div.div;
490 
491 	return div;
492 }
493 
494 static long
495 ingenic_clk_round_rate(struct clk_hw *hw, unsigned long req_rate,
496 		       unsigned long *parent_rate)
497 {
498 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
499 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
500 	unsigned int div = 1;
501 
502 	if (clk_info->type & CGU_CLK_DIV)
503 		div = ingenic_clk_calc_div(hw, clk_info, *parent_rate, req_rate);
504 	else if (clk_info->type & CGU_CLK_FIXDIV)
505 		div = clk_info->fixdiv.div;
506 	else if (clk_hw_can_set_rate_parent(hw))
507 		*parent_rate = req_rate;
508 
509 	return DIV_ROUND_UP(*parent_rate, div);
510 }
511 
512 static inline int ingenic_clk_check_stable(struct ingenic_cgu *cgu,
513 					   const struct ingenic_cgu_clk_info *clk_info)
514 {
515 	u32 reg;
516 
517 	return readl_poll_timeout(cgu->base + clk_info->div.reg, reg,
518 				  !(reg & BIT(clk_info->div.busy_bit)),
519 				  0, 100 * USEC_PER_MSEC);
520 }
521 
522 static int
523 ingenic_clk_set_rate(struct clk_hw *hw, unsigned long req_rate,
524 		     unsigned long parent_rate)
525 {
526 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
527 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
528 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
529 	unsigned long rate, flags;
530 	unsigned int hw_div, div;
531 	u32 reg, mask;
532 	int ret = 0;
533 
534 	if (clk_info->type & CGU_CLK_DIV) {
535 		div = ingenic_clk_calc_div(hw, clk_info, parent_rate, req_rate);
536 		rate = DIV_ROUND_UP(parent_rate, div);
537 
538 		if (rate != req_rate)
539 			return -EINVAL;
540 
541 		if (clk_info->div.div_table)
542 			hw_div = ingenic_clk_calc_hw_div(clk_info, div);
543 		else
544 			hw_div = ((div / clk_info->div.div) - 1);
545 
546 		spin_lock_irqsave(&cgu->lock, flags);
547 		reg = readl(cgu->base + clk_info->div.reg);
548 
549 		/* update the divide */
550 		mask = GENMASK(clk_info->div.bits - 1, 0);
551 		reg &= ~(mask << clk_info->div.shift);
552 		reg |= hw_div << clk_info->div.shift;
553 
554 		/* clear the stop bit */
555 		if (clk_info->div.stop_bit != -1)
556 			reg &= ~BIT(clk_info->div.stop_bit);
557 
558 		/* set the change enable bit */
559 		if (clk_info->div.ce_bit != -1)
560 			reg |= BIT(clk_info->div.ce_bit);
561 
562 		/* update the hardware */
563 		writel(reg, cgu->base + clk_info->div.reg);
564 
565 		/* wait for the change to take effect */
566 		if (clk_info->div.busy_bit != -1)
567 			ret = ingenic_clk_check_stable(cgu, clk_info);
568 
569 		spin_unlock_irqrestore(&cgu->lock, flags);
570 		return ret;
571 	}
572 
573 	return -EINVAL;
574 }
575 
576 static int ingenic_clk_enable(struct clk_hw *hw)
577 {
578 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
579 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
580 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
581 	unsigned long flags;
582 
583 	if (clk_info->type & CGU_CLK_GATE) {
584 		/* ungate the clock */
585 		spin_lock_irqsave(&cgu->lock, flags);
586 		ingenic_cgu_gate_set(cgu, &clk_info->gate, false);
587 		spin_unlock_irqrestore(&cgu->lock, flags);
588 
589 		if (clk_info->gate.delay_us)
590 			udelay(clk_info->gate.delay_us);
591 	}
592 
593 	return 0;
594 }
595 
596 static void ingenic_clk_disable(struct clk_hw *hw)
597 {
598 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
599 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
600 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
601 	unsigned long flags;
602 
603 	if (clk_info->type & CGU_CLK_GATE) {
604 		/* gate the clock */
605 		spin_lock_irqsave(&cgu->lock, flags);
606 		ingenic_cgu_gate_set(cgu, &clk_info->gate, true);
607 		spin_unlock_irqrestore(&cgu->lock, flags);
608 	}
609 }
610 
611 static int ingenic_clk_is_enabled(struct clk_hw *hw)
612 {
613 	struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
614 	const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
615 	struct ingenic_cgu *cgu = ingenic_clk->cgu;
616 	int enabled = 1;
617 
618 	if (clk_info->type & CGU_CLK_GATE)
619 		enabled = !ingenic_cgu_gate_get(cgu, &clk_info->gate);
620 
621 	return enabled;
622 }
623 
624 static const struct clk_ops ingenic_clk_ops = {
625 	.get_parent = ingenic_clk_get_parent,
626 	.set_parent = ingenic_clk_set_parent,
627 
628 	.recalc_rate = ingenic_clk_recalc_rate,
629 	.round_rate = ingenic_clk_round_rate,
630 	.set_rate = ingenic_clk_set_rate,
631 
632 	.enable = ingenic_clk_enable,
633 	.disable = ingenic_clk_disable,
634 	.is_enabled = ingenic_clk_is_enabled,
635 };
636 
637 /*
638  * Setup functions.
639  */
640 
641 static int ingenic_register_clock(struct ingenic_cgu *cgu, unsigned idx)
642 {
643 	const struct ingenic_cgu_clk_info *clk_info = &cgu->clock_info[idx];
644 	struct clk_init_data clk_init;
645 	struct ingenic_clk *ingenic_clk = NULL;
646 	struct clk *clk, *parent;
647 	const char *parent_names[4];
648 	unsigned caps, i, num_possible;
649 	int err = -EINVAL;
650 
651 	BUILD_BUG_ON(ARRAY_SIZE(clk_info->parents) > ARRAY_SIZE(parent_names));
652 
653 	if (clk_info->type == CGU_CLK_EXT) {
654 		clk = of_clk_get_by_name(cgu->np, clk_info->name);
655 		if (IS_ERR(clk)) {
656 			pr_err("%s: no external clock '%s' provided\n",
657 			       __func__, clk_info->name);
658 			err = -ENODEV;
659 			goto out;
660 		}
661 		err = clk_register_clkdev(clk, clk_info->name, NULL);
662 		if (err) {
663 			clk_put(clk);
664 			goto out;
665 		}
666 		cgu->clocks.clks[idx] = clk;
667 		return 0;
668 	}
669 
670 	if (!clk_info->type) {
671 		pr_err("%s: no clock type specified for '%s'\n", __func__,
672 		       clk_info->name);
673 		goto out;
674 	}
675 
676 	ingenic_clk = kzalloc(sizeof(*ingenic_clk), GFP_KERNEL);
677 	if (!ingenic_clk) {
678 		err = -ENOMEM;
679 		goto out;
680 	}
681 
682 	ingenic_clk->hw.init = &clk_init;
683 	ingenic_clk->cgu = cgu;
684 	ingenic_clk->idx = idx;
685 
686 	clk_init.name = clk_info->name;
687 	clk_init.flags = clk_info->flags;
688 	clk_init.parent_names = parent_names;
689 
690 	caps = clk_info->type;
691 
692 	if (caps & CGU_CLK_DIV) {
693 		caps &= ~CGU_CLK_DIV;
694 	} else if (!(caps & CGU_CLK_CUSTOM)) {
695 		/* pass rate changes to the parent clock */
696 		clk_init.flags |= CLK_SET_RATE_PARENT;
697 	}
698 
699 	if (caps & (CGU_CLK_MUX | CGU_CLK_CUSTOM)) {
700 		clk_init.num_parents = 0;
701 
702 		if (caps & CGU_CLK_MUX)
703 			num_possible = 1 << clk_info->mux.bits;
704 		else
705 			num_possible = ARRAY_SIZE(clk_info->parents);
706 
707 		for (i = 0; i < num_possible; i++) {
708 			if (clk_info->parents[i] == -1)
709 				continue;
710 
711 			parent = cgu->clocks.clks[clk_info->parents[i]];
712 			parent_names[clk_init.num_parents] =
713 				__clk_get_name(parent);
714 			clk_init.num_parents++;
715 		}
716 
717 		BUG_ON(!clk_init.num_parents);
718 		BUG_ON(clk_init.num_parents > ARRAY_SIZE(parent_names));
719 	} else {
720 		BUG_ON(clk_info->parents[0] == -1);
721 		clk_init.num_parents = 1;
722 		parent = cgu->clocks.clks[clk_info->parents[0]];
723 		parent_names[0] = __clk_get_name(parent);
724 	}
725 
726 	if (caps & CGU_CLK_CUSTOM) {
727 		clk_init.ops = clk_info->custom.clk_ops;
728 
729 		caps &= ~CGU_CLK_CUSTOM;
730 
731 		if (caps) {
732 			pr_err("%s: custom clock may not be combined with type 0x%x\n",
733 			       __func__, caps);
734 			goto out;
735 		}
736 	} else if (caps & CGU_CLK_PLL) {
737 		clk_init.ops = &ingenic_pll_ops;
738 
739 		caps &= ~CGU_CLK_PLL;
740 
741 		if (caps) {
742 			pr_err("%s: PLL may not be combined with type 0x%x\n",
743 			       __func__, caps);
744 			goto out;
745 		}
746 	} else {
747 		clk_init.ops = &ingenic_clk_ops;
748 	}
749 
750 	/* nothing to do for gates or fixed dividers */
751 	caps &= ~(CGU_CLK_GATE | CGU_CLK_FIXDIV);
752 
753 	if (caps & CGU_CLK_MUX) {
754 		if (!(caps & CGU_CLK_MUX_GLITCHFREE))
755 			clk_init.flags |= CLK_SET_PARENT_GATE;
756 
757 		caps &= ~(CGU_CLK_MUX | CGU_CLK_MUX_GLITCHFREE);
758 	}
759 
760 	if (caps) {
761 		pr_err("%s: unknown clock type 0x%x\n", __func__, caps);
762 		goto out;
763 	}
764 
765 	clk = clk_register(NULL, &ingenic_clk->hw);
766 	if (IS_ERR(clk)) {
767 		pr_err("%s: failed to register clock '%s'\n", __func__,
768 		       clk_info->name);
769 		err = PTR_ERR(clk);
770 		goto out;
771 	}
772 
773 	err = clk_register_clkdev(clk, clk_info->name, NULL);
774 	if (err)
775 		goto out;
776 
777 	cgu->clocks.clks[idx] = clk;
778 out:
779 	if (err)
780 		kfree(ingenic_clk);
781 	return err;
782 }
783 
784 struct ingenic_cgu *
785 ingenic_cgu_new(const struct ingenic_cgu_clk_info *clock_info,
786 		unsigned num_clocks, struct device_node *np)
787 {
788 	struct ingenic_cgu *cgu;
789 
790 	cgu = kzalloc(sizeof(*cgu), GFP_KERNEL);
791 	if (!cgu)
792 		goto err_out;
793 
794 	cgu->base = of_iomap(np, 0);
795 	if (!cgu->base) {
796 		pr_err("%s: failed to map CGU registers\n", __func__);
797 		goto err_out_free;
798 	}
799 
800 	cgu->np = np;
801 	cgu->clock_info = clock_info;
802 	cgu->clocks.clk_num = num_clocks;
803 
804 	spin_lock_init(&cgu->lock);
805 
806 	return cgu;
807 
808 err_out_free:
809 	kfree(cgu);
810 err_out:
811 	return NULL;
812 }
813 
814 int ingenic_cgu_register_clocks(struct ingenic_cgu *cgu)
815 {
816 	unsigned i;
817 	int err;
818 
819 	cgu->clocks.clks = kcalloc(cgu->clocks.clk_num, sizeof(struct clk *),
820 				   GFP_KERNEL);
821 	if (!cgu->clocks.clks) {
822 		err = -ENOMEM;
823 		goto err_out;
824 	}
825 
826 	for (i = 0; i < cgu->clocks.clk_num; i++) {
827 		err = ingenic_register_clock(cgu, i);
828 		if (err)
829 			goto err_out_unregister;
830 	}
831 
832 	err = of_clk_add_provider(cgu->np, of_clk_src_onecell_get,
833 				  &cgu->clocks);
834 	if (err)
835 		goto err_out_unregister;
836 
837 	return 0;
838 
839 err_out_unregister:
840 	for (i = 0; i < cgu->clocks.clk_num; i++) {
841 		if (!cgu->clocks.clks[i])
842 			continue;
843 		if (cgu->clock_info[i].type & CGU_CLK_EXT)
844 			clk_put(cgu->clocks.clks[i]);
845 		else
846 			clk_unregister(cgu->clocks.clks[i]);
847 	}
848 	kfree(cgu->clocks.clks);
849 err_out:
850 	return err;
851 }
852