xref: /linux/drivers/clk/at91/clk-main.c (revision 8f697e574012cc73b6b0dcbf30d88a3a0f43b78f)
1 /*
2  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  */
10 
11 #include <linux/clk-provider.h>
12 #include <linux/clkdev.h>
13 #include <linux/clk/at91_pmc.h>
14 #include <linux/delay.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/of_irq.h>
18 #include <linux/io.h>
19 #include <linux/interrupt.h>
20 #include <linux/irq.h>
21 #include <linux/sched.h>
22 #include <linux/wait.h>
23 
24 #include "pmc.h"
25 
26 #define SLOW_CLOCK_FREQ		32768
27 #define MAINF_DIV		16
28 #define MAINFRDY_TIMEOUT	(((MAINF_DIV + 1) * USEC_PER_SEC) / \
29 				 SLOW_CLOCK_FREQ)
30 #define MAINF_LOOP_MIN_WAIT	(USEC_PER_SEC / SLOW_CLOCK_FREQ)
31 #define MAINF_LOOP_MAX_WAIT	MAINFRDY_TIMEOUT
32 
33 #define MOR_KEY_MASK		(0xff << 16)
34 
35 struct clk_main_osc {
36 	struct clk_hw hw;
37 	struct at91_pmc *pmc;
38 	unsigned int irq;
39 	wait_queue_head_t wait;
40 };
41 
42 #define to_clk_main_osc(hw) container_of(hw, struct clk_main_osc, hw)
43 
44 struct clk_main_rc_osc {
45 	struct clk_hw hw;
46 	struct at91_pmc *pmc;
47 	unsigned int irq;
48 	wait_queue_head_t wait;
49 	unsigned long frequency;
50 	unsigned long accuracy;
51 };
52 
53 #define to_clk_main_rc_osc(hw) container_of(hw, struct clk_main_rc_osc, hw)
54 
55 struct clk_rm9200_main {
56 	struct clk_hw hw;
57 	struct at91_pmc *pmc;
58 };
59 
60 #define to_clk_rm9200_main(hw) container_of(hw, struct clk_rm9200_main, hw)
61 
62 struct clk_sam9x5_main {
63 	struct clk_hw hw;
64 	struct at91_pmc *pmc;
65 	unsigned int irq;
66 	wait_queue_head_t wait;
67 	u8 parent;
68 };
69 
70 #define to_clk_sam9x5_main(hw) container_of(hw, struct clk_sam9x5_main, hw)
71 
72 static irqreturn_t clk_main_osc_irq_handler(int irq, void *dev_id)
73 {
74 	struct clk_main_osc *osc = dev_id;
75 
76 	wake_up(&osc->wait);
77 	disable_irq_nosync(osc->irq);
78 
79 	return IRQ_HANDLED;
80 }
81 
82 static int clk_main_osc_prepare(struct clk_hw *hw)
83 {
84 	struct clk_main_osc *osc = to_clk_main_osc(hw);
85 	struct at91_pmc *pmc = osc->pmc;
86 	u32 tmp;
87 
88 	tmp = pmc_read(pmc, AT91_CKGR_MOR) & ~MOR_KEY_MASK;
89 	if (tmp & AT91_PMC_OSCBYPASS)
90 		return 0;
91 
92 	if (!(tmp & AT91_PMC_MOSCEN)) {
93 		tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY;
94 		pmc_write(pmc, AT91_CKGR_MOR, tmp);
95 	}
96 
97 	while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS)) {
98 		enable_irq(osc->irq);
99 		wait_event(osc->wait,
100 			   pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS);
101 	}
102 
103 	return 0;
104 }
105 
106 static void clk_main_osc_unprepare(struct clk_hw *hw)
107 {
108 	struct clk_main_osc *osc = to_clk_main_osc(hw);
109 	struct at91_pmc *pmc = osc->pmc;
110 	u32 tmp = pmc_read(pmc, AT91_CKGR_MOR);
111 
112 	if (tmp & AT91_PMC_OSCBYPASS)
113 		return;
114 
115 	if (!(tmp & AT91_PMC_MOSCEN))
116 		return;
117 
118 	tmp &= ~(AT91_PMC_KEY | AT91_PMC_MOSCEN);
119 	pmc_write(pmc, AT91_CKGR_MOR, tmp | AT91_PMC_KEY);
120 }
121 
122 static int clk_main_osc_is_prepared(struct clk_hw *hw)
123 {
124 	struct clk_main_osc *osc = to_clk_main_osc(hw);
125 	struct at91_pmc *pmc = osc->pmc;
126 	u32 tmp = pmc_read(pmc, AT91_CKGR_MOR);
127 
128 	if (tmp & AT91_PMC_OSCBYPASS)
129 		return 1;
130 
131 	return !!((pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS) &&
132 		  (pmc_read(pmc, AT91_CKGR_MOR) & AT91_PMC_MOSCEN));
133 }
134 
135 static const struct clk_ops main_osc_ops = {
136 	.prepare = clk_main_osc_prepare,
137 	.unprepare = clk_main_osc_unprepare,
138 	.is_prepared = clk_main_osc_is_prepared,
139 };
140 
141 static struct clk * __init
142 at91_clk_register_main_osc(struct at91_pmc *pmc,
143 			   unsigned int irq,
144 			   const char *name,
145 			   const char *parent_name,
146 			   bool bypass)
147 {
148 	int ret;
149 	struct clk_main_osc *osc;
150 	struct clk *clk = NULL;
151 	struct clk_init_data init;
152 
153 	if (!pmc || !irq || !name || !parent_name)
154 		return ERR_PTR(-EINVAL);
155 
156 	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
157 	if (!osc)
158 		return ERR_PTR(-ENOMEM);
159 
160 	init.name = name;
161 	init.ops = &main_osc_ops;
162 	init.parent_names = &parent_name;
163 	init.num_parents = 1;
164 	init.flags = CLK_IGNORE_UNUSED;
165 
166 	osc->hw.init = &init;
167 	osc->pmc = pmc;
168 	osc->irq = irq;
169 
170 	init_waitqueue_head(&osc->wait);
171 	irq_set_status_flags(osc->irq, IRQ_NOAUTOEN);
172 	ret = request_irq(osc->irq, clk_main_osc_irq_handler,
173 			  IRQF_TRIGGER_HIGH, name, osc);
174 	if (ret) {
175 		kfree(osc);
176 		return ERR_PTR(ret);
177 	}
178 
179 	if (bypass)
180 		pmc_write(pmc, AT91_CKGR_MOR,
181 			  (pmc_read(pmc, AT91_CKGR_MOR) &
182 			   ~(MOR_KEY_MASK | AT91_PMC_MOSCEN)) |
183 			  AT91_PMC_OSCBYPASS | AT91_PMC_KEY);
184 
185 	clk = clk_register(NULL, &osc->hw);
186 	if (IS_ERR(clk)) {
187 		free_irq(irq, osc);
188 		kfree(osc);
189 	}
190 
191 	return clk;
192 }
193 
194 void __init of_at91rm9200_clk_main_osc_setup(struct device_node *np,
195 					     struct at91_pmc *pmc)
196 {
197 	struct clk *clk;
198 	unsigned int irq;
199 	const char *name = np->name;
200 	const char *parent_name;
201 	bool bypass;
202 
203 	of_property_read_string(np, "clock-output-names", &name);
204 	bypass = of_property_read_bool(np, "atmel,osc-bypass");
205 	parent_name = of_clk_get_parent_name(np, 0);
206 
207 	irq = irq_of_parse_and_map(np, 0);
208 	if (!irq)
209 		return;
210 
211 	clk = at91_clk_register_main_osc(pmc, irq, name, parent_name, bypass);
212 	if (IS_ERR(clk))
213 		return;
214 
215 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
216 }
217 
218 static irqreturn_t clk_main_rc_osc_irq_handler(int irq, void *dev_id)
219 {
220 	struct clk_main_rc_osc *osc = dev_id;
221 
222 	wake_up(&osc->wait);
223 	disable_irq_nosync(osc->irq);
224 
225 	return IRQ_HANDLED;
226 }
227 
228 static int clk_main_rc_osc_prepare(struct clk_hw *hw)
229 {
230 	struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
231 	struct at91_pmc *pmc = osc->pmc;
232 	u32 tmp;
233 
234 	tmp = pmc_read(pmc, AT91_CKGR_MOR) & ~MOR_KEY_MASK;
235 
236 	if (!(tmp & AT91_PMC_MOSCRCEN)) {
237 		tmp |= AT91_PMC_MOSCRCEN | AT91_PMC_KEY;
238 		pmc_write(pmc, AT91_CKGR_MOR, tmp);
239 	}
240 
241 	while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCRCS)) {
242 		enable_irq(osc->irq);
243 		wait_event(osc->wait,
244 			   pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCRCS);
245 	}
246 
247 	return 0;
248 }
249 
250 static void clk_main_rc_osc_unprepare(struct clk_hw *hw)
251 {
252 	struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
253 	struct at91_pmc *pmc = osc->pmc;
254 	u32 tmp = pmc_read(pmc, AT91_CKGR_MOR);
255 
256 	if (!(tmp & AT91_PMC_MOSCRCEN))
257 		return;
258 
259 	tmp &= ~(MOR_KEY_MASK | AT91_PMC_MOSCRCEN);
260 	pmc_write(pmc, AT91_CKGR_MOR, tmp | AT91_PMC_KEY);
261 }
262 
263 static int clk_main_rc_osc_is_prepared(struct clk_hw *hw)
264 {
265 	struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
266 	struct at91_pmc *pmc = osc->pmc;
267 
268 	return !!((pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCRCS) &&
269 		  (pmc_read(pmc, AT91_CKGR_MOR) & AT91_PMC_MOSCRCEN));
270 }
271 
272 static unsigned long clk_main_rc_osc_recalc_rate(struct clk_hw *hw,
273 						 unsigned long parent_rate)
274 {
275 	struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
276 
277 	return osc->frequency;
278 }
279 
280 static unsigned long clk_main_rc_osc_recalc_accuracy(struct clk_hw *hw,
281 						     unsigned long parent_acc)
282 {
283 	struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
284 
285 	return osc->accuracy;
286 }
287 
288 static const struct clk_ops main_rc_osc_ops = {
289 	.prepare = clk_main_rc_osc_prepare,
290 	.unprepare = clk_main_rc_osc_unprepare,
291 	.is_prepared = clk_main_rc_osc_is_prepared,
292 	.recalc_rate = clk_main_rc_osc_recalc_rate,
293 	.recalc_accuracy = clk_main_rc_osc_recalc_accuracy,
294 };
295 
296 static struct clk * __init
297 at91_clk_register_main_rc_osc(struct at91_pmc *pmc,
298 			      unsigned int irq,
299 			      const char *name,
300 			      u32 frequency, u32 accuracy)
301 {
302 	int ret;
303 	struct clk_main_rc_osc *osc;
304 	struct clk *clk = NULL;
305 	struct clk_init_data init;
306 
307 	if (!pmc || !irq || !name || !frequency)
308 		return ERR_PTR(-EINVAL);
309 
310 	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
311 	if (!osc)
312 		return ERR_PTR(-ENOMEM);
313 
314 	init.name = name;
315 	init.ops = &main_rc_osc_ops;
316 	init.parent_names = NULL;
317 	init.num_parents = 0;
318 	init.flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED;
319 
320 	osc->hw.init = &init;
321 	osc->pmc = pmc;
322 	osc->irq = irq;
323 	osc->frequency = frequency;
324 	osc->accuracy = accuracy;
325 
326 	init_waitqueue_head(&osc->wait);
327 	irq_set_status_flags(osc->irq, IRQ_NOAUTOEN);
328 	ret = request_irq(osc->irq, clk_main_rc_osc_irq_handler,
329 			  IRQF_TRIGGER_HIGH, name, osc);
330 	if (ret)
331 		return ERR_PTR(ret);
332 
333 	clk = clk_register(NULL, &osc->hw);
334 	if (IS_ERR(clk)) {
335 		free_irq(irq, osc);
336 		kfree(osc);
337 	}
338 
339 	return clk;
340 }
341 
342 void __init of_at91sam9x5_clk_main_rc_osc_setup(struct device_node *np,
343 						struct at91_pmc *pmc)
344 {
345 	struct clk *clk;
346 	unsigned int irq;
347 	u32 frequency = 0;
348 	u32 accuracy = 0;
349 	const char *name = np->name;
350 
351 	of_property_read_string(np, "clock-output-names", &name);
352 	of_property_read_u32(np, "clock-frequency", &frequency);
353 	of_property_read_u32(np, "clock-accuracy", &accuracy);
354 
355 	irq = irq_of_parse_and_map(np, 0);
356 	if (!irq)
357 		return;
358 
359 	clk = at91_clk_register_main_rc_osc(pmc, irq, name, frequency,
360 					    accuracy);
361 	if (IS_ERR(clk))
362 		return;
363 
364 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
365 }
366 
367 
368 static int clk_main_probe_frequency(struct at91_pmc *pmc)
369 {
370 	unsigned long prep_time, timeout;
371 	u32 tmp;
372 
373 	timeout = jiffies + usecs_to_jiffies(MAINFRDY_TIMEOUT);
374 	do {
375 		prep_time = jiffies;
376 		tmp = pmc_read(pmc, AT91_CKGR_MCFR);
377 		if (tmp & AT91_PMC_MAINRDY)
378 			return 0;
379 		usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT);
380 	} while (time_before(prep_time, timeout));
381 
382 	return -ETIMEDOUT;
383 }
384 
385 static unsigned long clk_main_recalc_rate(struct at91_pmc *pmc,
386 					  unsigned long parent_rate)
387 {
388 	u32 tmp;
389 
390 	if (parent_rate)
391 		return parent_rate;
392 
393 	pr_warn("Main crystal frequency not set, using approximate value\n");
394 	tmp = pmc_read(pmc, AT91_CKGR_MCFR);
395 	if (!(tmp & AT91_PMC_MAINRDY))
396 		return 0;
397 
398 	return ((tmp & AT91_PMC_MAINF) * SLOW_CLOCK_FREQ) / MAINF_DIV;
399 }
400 
401 static int clk_rm9200_main_prepare(struct clk_hw *hw)
402 {
403 	struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
404 
405 	return clk_main_probe_frequency(clkmain->pmc);
406 }
407 
408 static int clk_rm9200_main_is_prepared(struct clk_hw *hw)
409 {
410 	struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
411 
412 	return !!(pmc_read(clkmain->pmc, AT91_CKGR_MCFR) & AT91_PMC_MAINRDY);
413 }
414 
415 static unsigned long clk_rm9200_main_recalc_rate(struct clk_hw *hw,
416 						 unsigned long parent_rate)
417 {
418 	struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
419 
420 	return clk_main_recalc_rate(clkmain->pmc, parent_rate);
421 }
422 
423 static const struct clk_ops rm9200_main_ops = {
424 	.prepare = clk_rm9200_main_prepare,
425 	.is_prepared = clk_rm9200_main_is_prepared,
426 	.recalc_rate = clk_rm9200_main_recalc_rate,
427 };
428 
429 static struct clk * __init
430 at91_clk_register_rm9200_main(struct at91_pmc *pmc,
431 			      const char *name,
432 			      const char *parent_name)
433 {
434 	struct clk_rm9200_main *clkmain;
435 	struct clk *clk = NULL;
436 	struct clk_init_data init;
437 
438 	if (!pmc || !name)
439 		return ERR_PTR(-EINVAL);
440 
441 	if (!parent_name)
442 		return ERR_PTR(-EINVAL);
443 
444 	clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
445 	if (!clkmain)
446 		return ERR_PTR(-ENOMEM);
447 
448 	init.name = name;
449 	init.ops = &rm9200_main_ops;
450 	init.parent_names = &parent_name;
451 	init.num_parents = 1;
452 	init.flags = 0;
453 
454 	clkmain->hw.init = &init;
455 	clkmain->pmc = pmc;
456 
457 	clk = clk_register(NULL, &clkmain->hw);
458 	if (IS_ERR(clk))
459 		kfree(clkmain);
460 
461 	return clk;
462 }
463 
464 void __init of_at91rm9200_clk_main_setup(struct device_node *np,
465 					 struct at91_pmc *pmc)
466 {
467 	struct clk *clk;
468 	const char *parent_name;
469 	const char *name = np->name;
470 
471 	parent_name = of_clk_get_parent_name(np, 0);
472 	of_property_read_string(np, "clock-output-names", &name);
473 
474 	clk = at91_clk_register_rm9200_main(pmc, name, parent_name);
475 	if (IS_ERR(clk))
476 		return;
477 
478 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
479 }
480 
481 static irqreturn_t clk_sam9x5_main_irq_handler(int irq, void *dev_id)
482 {
483 	struct clk_sam9x5_main *clkmain = dev_id;
484 
485 	wake_up(&clkmain->wait);
486 	disable_irq_nosync(clkmain->irq);
487 
488 	return IRQ_HANDLED;
489 }
490 
491 static int clk_sam9x5_main_prepare(struct clk_hw *hw)
492 {
493 	struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
494 	struct at91_pmc *pmc = clkmain->pmc;
495 
496 	while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS)) {
497 		enable_irq(clkmain->irq);
498 		wait_event(clkmain->wait,
499 			   pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS);
500 	}
501 
502 	return clk_main_probe_frequency(pmc);
503 }
504 
505 static int clk_sam9x5_main_is_prepared(struct clk_hw *hw)
506 {
507 	struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
508 
509 	return !!(pmc_read(clkmain->pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS);
510 }
511 
512 static unsigned long clk_sam9x5_main_recalc_rate(struct clk_hw *hw,
513 						 unsigned long parent_rate)
514 {
515 	struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
516 
517 	return clk_main_recalc_rate(clkmain->pmc, parent_rate);
518 }
519 
520 static int clk_sam9x5_main_set_parent(struct clk_hw *hw, u8 index)
521 {
522 	struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
523 	struct at91_pmc *pmc = clkmain->pmc;
524 	u32 tmp;
525 
526 	if (index > 1)
527 		return -EINVAL;
528 
529 	tmp = pmc_read(pmc, AT91_CKGR_MOR) & ~MOR_KEY_MASK;
530 
531 	if (index && !(tmp & AT91_PMC_MOSCSEL))
532 		pmc_write(pmc, AT91_CKGR_MOR, tmp | AT91_PMC_MOSCSEL);
533 	else if (!index && (tmp & AT91_PMC_MOSCSEL))
534 		pmc_write(pmc, AT91_CKGR_MOR, tmp & ~AT91_PMC_MOSCSEL);
535 
536 	while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS)) {
537 		enable_irq(clkmain->irq);
538 		wait_event(clkmain->wait,
539 			   pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS);
540 	}
541 
542 	return 0;
543 }
544 
545 static u8 clk_sam9x5_main_get_parent(struct clk_hw *hw)
546 {
547 	struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
548 
549 	return !!(pmc_read(clkmain->pmc, AT91_CKGR_MOR) & AT91_PMC_MOSCEN);
550 }
551 
552 static const struct clk_ops sam9x5_main_ops = {
553 	.prepare = clk_sam9x5_main_prepare,
554 	.is_prepared = clk_sam9x5_main_is_prepared,
555 	.recalc_rate = clk_sam9x5_main_recalc_rate,
556 	.set_parent = clk_sam9x5_main_set_parent,
557 	.get_parent = clk_sam9x5_main_get_parent,
558 };
559 
560 static struct clk * __init
561 at91_clk_register_sam9x5_main(struct at91_pmc *pmc,
562 			      unsigned int irq,
563 			      const char *name,
564 			      const char **parent_names,
565 			      int num_parents)
566 {
567 	int ret;
568 	struct clk_sam9x5_main *clkmain;
569 	struct clk *clk = NULL;
570 	struct clk_init_data init;
571 
572 	if (!pmc || !irq || !name)
573 		return ERR_PTR(-EINVAL);
574 
575 	if (!parent_names || !num_parents)
576 		return ERR_PTR(-EINVAL);
577 
578 	clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
579 	if (!clkmain)
580 		return ERR_PTR(-ENOMEM);
581 
582 	init.name = name;
583 	init.ops = &sam9x5_main_ops;
584 	init.parent_names = parent_names;
585 	init.num_parents = num_parents;
586 	init.flags = CLK_SET_PARENT_GATE;
587 
588 	clkmain->hw.init = &init;
589 	clkmain->pmc = pmc;
590 	clkmain->irq = irq;
591 	clkmain->parent = !!(pmc_read(clkmain->pmc, AT91_CKGR_MOR) &
592 			     AT91_PMC_MOSCEN);
593 	init_waitqueue_head(&clkmain->wait);
594 	irq_set_status_flags(clkmain->irq, IRQ_NOAUTOEN);
595 	ret = request_irq(clkmain->irq, clk_sam9x5_main_irq_handler,
596 			  IRQF_TRIGGER_HIGH, name, clkmain);
597 	if (ret)
598 		return ERR_PTR(ret);
599 
600 	clk = clk_register(NULL, &clkmain->hw);
601 	if (IS_ERR(clk)) {
602 		free_irq(clkmain->irq, clkmain);
603 		kfree(clkmain);
604 	}
605 
606 	return clk;
607 }
608 
609 void __init of_at91sam9x5_clk_main_setup(struct device_node *np,
610 					 struct at91_pmc *pmc)
611 {
612 	struct clk *clk;
613 	const char *parent_names[2];
614 	int num_parents;
615 	unsigned int irq;
616 	const char *name = np->name;
617 
618 	num_parents = of_clk_get_parent_count(np);
619 	if (num_parents <= 0 || num_parents > 2)
620 		return;
621 
622 	of_clk_parent_fill(np, parent_names, num_parents);
623 
624 	of_property_read_string(np, "clock-output-names", &name);
625 
626 	irq = irq_of_parse_and_map(np, 0);
627 	if (!irq)
628 		return;
629 
630 	clk = at91_clk_register_sam9x5_main(pmc, irq, name, parent_names,
631 					    num_parents);
632 	if (IS_ERR(clk))
633 		return;
634 
635 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
636 }
637