xref: /openbmc/linux/drivers/clk/tegra/clk-bpmp.c (revision c4a7b9b5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2016-2020 NVIDIA Corporation
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/device.h>
8 #include <linux/seq_buf.h>
9 #include <linux/slab.h>
10 
11 #include <soc/tegra/bpmp.h>
12 #include <soc/tegra/bpmp-abi.h>
13 
14 #define TEGRA_BPMP_DUMP_CLOCK_INFO	0
15 
16 #define TEGRA_BPMP_CLK_HAS_MUX		BIT(0)
17 #define TEGRA_BPMP_CLK_HAS_SET_RATE	BIT(1)
18 #define TEGRA_BPMP_CLK_IS_ROOT		BIT(2)
19 
20 struct tegra_bpmp_clk_info {
21 	unsigned int id;
22 	char name[MRQ_CLK_NAME_MAXLEN];
23 	unsigned int parents[MRQ_CLK_MAX_PARENTS];
24 	unsigned int num_parents;
25 	unsigned long flags;
26 };
27 
28 struct tegra_bpmp_clk {
29 	struct clk_hw hw;
30 
31 	struct tegra_bpmp *bpmp;
32 	unsigned int id;
33 
34 	unsigned int num_parents;
35 	unsigned int *parents;
36 };
37 
38 static inline struct tegra_bpmp_clk *to_tegra_bpmp_clk(struct clk_hw *hw)
39 {
40 	return container_of(hw, struct tegra_bpmp_clk, hw);
41 }
42 
43 struct tegra_bpmp_clk_message {
44 	unsigned int cmd;
45 	unsigned int id;
46 
47 	struct {
48 		const void *data;
49 		size_t size;
50 	} tx;
51 
52 	struct {
53 		void *data;
54 		size_t size;
55 		int ret;
56 	} rx;
57 };
58 
59 static int tegra_bpmp_clk_transfer(struct tegra_bpmp *bpmp,
60 				   const struct tegra_bpmp_clk_message *clk)
61 {
62 	struct mrq_clk_request request;
63 	struct tegra_bpmp_message msg;
64 	void *req = &request;
65 	int err;
66 
67 	memset(&request, 0, sizeof(request));
68 	request.cmd_and_id = (clk->cmd << 24) | clk->id;
69 
70 	/*
71 	 * The mrq_clk_request structure has an anonymous union at offset 4
72 	 * that contains all possible sub-command structures. Copy the data
73 	 * to that union. Ideally we'd be able to refer to it by name, but
74 	 * doing so would require changing the ABI header and increase the
75 	 * maintenance burden.
76 	 */
77 	memcpy(req + 4, clk->tx.data, clk->tx.size);
78 
79 	memset(&msg, 0, sizeof(msg));
80 	msg.mrq = MRQ_CLK;
81 	msg.tx.data = &request;
82 	msg.tx.size = sizeof(request);
83 	msg.rx.data = clk->rx.data;
84 	msg.rx.size = clk->rx.size;
85 
86 	err = tegra_bpmp_transfer(bpmp, &msg);
87 	if (err < 0)
88 		return err;
89 	else if (msg.rx.ret < 0)
90 		return -EINVAL;
91 
92 	return 0;
93 }
94 
95 static int tegra_bpmp_clk_prepare(struct clk_hw *hw)
96 {
97 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
98 	struct tegra_bpmp_clk_message msg;
99 
100 	memset(&msg, 0, sizeof(msg));
101 	msg.cmd = CMD_CLK_ENABLE;
102 	msg.id = clk->id;
103 
104 	return tegra_bpmp_clk_transfer(clk->bpmp, &msg);
105 }
106 
107 static void tegra_bpmp_clk_unprepare(struct clk_hw *hw)
108 {
109 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
110 	struct tegra_bpmp_clk_message msg;
111 	int err;
112 
113 	memset(&msg, 0, sizeof(msg));
114 	msg.cmd = CMD_CLK_DISABLE;
115 	msg.id = clk->id;
116 
117 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
118 	if (err < 0)
119 		dev_err(clk->bpmp->dev, "failed to disable clock %s: %d\n",
120 			clk_hw_get_name(hw), err);
121 }
122 
123 static int tegra_bpmp_clk_is_prepared(struct clk_hw *hw)
124 {
125 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
126 	struct cmd_clk_is_enabled_response response;
127 	struct tegra_bpmp_clk_message msg;
128 	int err;
129 
130 	memset(&msg, 0, sizeof(msg));
131 	msg.cmd = CMD_CLK_IS_ENABLED;
132 	msg.id = clk->id;
133 	msg.rx.data = &response;
134 	msg.rx.size = sizeof(response);
135 
136 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
137 	if (err < 0)
138 		return err;
139 
140 	return response.state;
141 }
142 
143 static unsigned long tegra_bpmp_clk_recalc_rate(struct clk_hw *hw,
144 						unsigned long parent_rate)
145 {
146 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
147 	struct cmd_clk_get_rate_response response;
148 	struct cmd_clk_get_rate_request request;
149 	struct tegra_bpmp_clk_message msg;
150 	int err;
151 
152 	memset(&msg, 0, sizeof(msg));
153 	msg.cmd = CMD_CLK_GET_RATE;
154 	msg.id = clk->id;
155 	msg.tx.data = &request;
156 	msg.tx.size = sizeof(request);
157 	msg.rx.data = &response;
158 	msg.rx.size = sizeof(response);
159 
160 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
161 	if (err < 0)
162 		return err;
163 
164 	return response.rate;
165 }
166 
167 static int tegra_bpmp_clk_determine_rate(struct clk_hw *hw,
168 					 struct clk_rate_request *rate_req)
169 {
170 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
171 	struct cmd_clk_round_rate_response response;
172 	struct cmd_clk_round_rate_request request;
173 	struct tegra_bpmp_clk_message msg;
174 	unsigned long rate;
175 	int err;
176 
177 	rate = min(max(rate_req->rate, rate_req->min_rate), rate_req->max_rate);
178 
179 	memset(&request, 0, sizeof(request));
180 	request.rate = min_t(u64, rate, S64_MAX);
181 
182 	memset(&msg, 0, sizeof(msg));
183 	msg.cmd = CMD_CLK_ROUND_RATE;
184 	msg.id = clk->id;
185 	msg.tx.data = &request;
186 	msg.tx.size = sizeof(request);
187 	msg.rx.data = &response;
188 	msg.rx.size = sizeof(response);
189 
190 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
191 	if (err < 0)
192 		return err;
193 
194 	rate_req->rate = (unsigned long)response.rate;
195 
196 	return 0;
197 }
198 
199 static int tegra_bpmp_clk_set_parent(struct clk_hw *hw, u8 index)
200 {
201 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
202 	struct cmd_clk_set_parent_response response;
203 	struct cmd_clk_set_parent_request request;
204 	struct tegra_bpmp_clk_message msg;
205 	int err;
206 
207 	memset(&request, 0, sizeof(request));
208 	request.parent_id = clk->parents[index];
209 
210 	memset(&msg, 0, sizeof(msg));
211 	msg.cmd = CMD_CLK_SET_PARENT;
212 	msg.id = clk->id;
213 	msg.tx.data = &request;
214 	msg.tx.size = sizeof(request);
215 	msg.rx.data = &response;
216 	msg.rx.size = sizeof(response);
217 
218 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
219 	if (err < 0)
220 		return err;
221 
222 	/* XXX check parent ID in response */
223 
224 	return 0;
225 }
226 
227 static u8 tegra_bpmp_clk_get_parent(struct clk_hw *hw)
228 {
229 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
230 	struct cmd_clk_get_parent_response response;
231 	struct tegra_bpmp_clk_message msg;
232 	unsigned int i;
233 	int err;
234 
235 	memset(&msg, 0, sizeof(msg));
236 	msg.cmd = CMD_CLK_GET_PARENT;
237 	msg.id = clk->id;
238 	msg.rx.data = &response;
239 	msg.rx.size = sizeof(response);
240 
241 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
242 	if (err < 0) {
243 		dev_err(clk->bpmp->dev, "failed to get parent for %s: %d\n",
244 			clk_hw_get_name(hw), err);
245 		return U8_MAX;
246 	}
247 
248 	for (i = 0; i < clk->num_parents; i++)
249 		if (clk->parents[i] == response.parent_id)
250 			return i;
251 
252 	return U8_MAX;
253 }
254 
255 static int tegra_bpmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
256 				   unsigned long parent_rate)
257 {
258 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
259 	struct cmd_clk_set_rate_response response;
260 	struct cmd_clk_set_rate_request request;
261 	struct tegra_bpmp_clk_message msg;
262 
263 	memset(&request, 0, sizeof(request));
264 	request.rate = min_t(u64, rate, S64_MAX);
265 
266 	memset(&msg, 0, sizeof(msg));
267 	msg.cmd = CMD_CLK_SET_RATE;
268 	msg.id = clk->id;
269 	msg.tx.data = &request;
270 	msg.tx.size = sizeof(request);
271 	msg.rx.data = &response;
272 	msg.rx.size = sizeof(response);
273 
274 	return tegra_bpmp_clk_transfer(clk->bpmp, &msg);
275 }
276 
277 static const struct clk_ops tegra_bpmp_clk_gate_ops = {
278 	.prepare = tegra_bpmp_clk_prepare,
279 	.unprepare = tegra_bpmp_clk_unprepare,
280 	.is_prepared = tegra_bpmp_clk_is_prepared,
281 	.recalc_rate = tegra_bpmp_clk_recalc_rate,
282 };
283 
284 static const struct clk_ops tegra_bpmp_clk_mux_ops = {
285 	.prepare = tegra_bpmp_clk_prepare,
286 	.unprepare = tegra_bpmp_clk_unprepare,
287 	.is_prepared = tegra_bpmp_clk_is_prepared,
288 	.recalc_rate = tegra_bpmp_clk_recalc_rate,
289 	.set_parent = tegra_bpmp_clk_set_parent,
290 	.get_parent = tegra_bpmp_clk_get_parent,
291 };
292 
293 static const struct clk_ops tegra_bpmp_clk_rate_ops = {
294 	.prepare = tegra_bpmp_clk_prepare,
295 	.unprepare = tegra_bpmp_clk_unprepare,
296 	.is_prepared = tegra_bpmp_clk_is_prepared,
297 	.recalc_rate = tegra_bpmp_clk_recalc_rate,
298 	.determine_rate = tegra_bpmp_clk_determine_rate,
299 	.set_rate = tegra_bpmp_clk_set_rate,
300 };
301 
302 static const struct clk_ops tegra_bpmp_clk_mux_rate_ops = {
303 	.prepare = tegra_bpmp_clk_prepare,
304 	.unprepare = tegra_bpmp_clk_unprepare,
305 	.is_prepared = tegra_bpmp_clk_is_prepared,
306 	.recalc_rate = tegra_bpmp_clk_recalc_rate,
307 	.determine_rate = tegra_bpmp_clk_determine_rate,
308 	.set_parent = tegra_bpmp_clk_set_parent,
309 	.get_parent = tegra_bpmp_clk_get_parent,
310 	.set_rate = tegra_bpmp_clk_set_rate,
311 };
312 
313 static int tegra_bpmp_clk_get_max_id(struct tegra_bpmp *bpmp)
314 {
315 	struct cmd_clk_get_max_clk_id_response response;
316 	struct tegra_bpmp_clk_message msg;
317 	int err;
318 
319 	memset(&msg, 0, sizeof(msg));
320 	msg.cmd = CMD_CLK_GET_MAX_CLK_ID;
321 	msg.rx.data = &response;
322 	msg.rx.size = sizeof(response);
323 
324 	err = tegra_bpmp_clk_transfer(bpmp, &msg);
325 	if (err < 0)
326 		return err;
327 
328 	if (response.max_id > INT_MAX)
329 		return -E2BIG;
330 
331 	return response.max_id;
332 }
333 
334 static int tegra_bpmp_clk_get_info(struct tegra_bpmp *bpmp, unsigned int id,
335 				   struct tegra_bpmp_clk_info *info)
336 {
337 	struct cmd_clk_get_all_info_response response;
338 	struct tegra_bpmp_clk_message msg;
339 	unsigned int i;
340 	int err;
341 
342 	memset(&msg, 0, sizeof(msg));
343 	msg.cmd = CMD_CLK_GET_ALL_INFO;
344 	msg.id = id;
345 	msg.rx.data = &response;
346 	msg.rx.size = sizeof(response);
347 
348 	err = tegra_bpmp_clk_transfer(bpmp, &msg);
349 	if (err < 0)
350 		return err;
351 
352 	strscpy(info->name, response.name, MRQ_CLK_NAME_MAXLEN);
353 	info->num_parents = response.num_parents;
354 
355 	for (i = 0; i < info->num_parents; i++)
356 		info->parents[i] = response.parents[i];
357 
358 	info->flags = response.flags;
359 
360 	return 0;
361 }
362 
363 static void tegra_bpmp_clk_info_dump(struct tegra_bpmp *bpmp,
364 				     const char *level,
365 				     const struct tegra_bpmp_clk_info *info)
366 {
367 	const char *prefix = "";
368 	struct seq_buf buf;
369 	unsigned int i;
370 	char flags[64];
371 
372 	seq_buf_init(&buf, flags, sizeof(flags));
373 
374 	if (info->flags)
375 		seq_buf_printf(&buf, "(");
376 
377 	if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
378 		seq_buf_printf(&buf, "%smux", prefix);
379 		prefix = ", ";
380 	}
381 
382 	if ((info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE) == 0) {
383 		seq_buf_printf(&buf, "%sfixed", prefix);
384 		prefix = ", ";
385 	}
386 
387 	if (info->flags & TEGRA_BPMP_CLK_IS_ROOT) {
388 		seq_buf_printf(&buf, "%sroot", prefix);
389 		prefix = ", ";
390 	}
391 
392 	if (info->flags)
393 		seq_buf_printf(&buf, ")");
394 
395 	dev_printk(level, bpmp->dev, "%03u: %s\n", info->id, info->name);
396 	dev_printk(level, bpmp->dev, "  flags: %lx %s\n", info->flags, flags);
397 	dev_printk(level, bpmp->dev, "  parents: %u\n", info->num_parents);
398 
399 	for (i = 0; i < info->num_parents; i++)
400 		dev_printk(level, bpmp->dev, "    %03u\n", info->parents[i]);
401 }
402 
403 static int tegra_bpmp_probe_clocks(struct tegra_bpmp *bpmp,
404 				   struct tegra_bpmp_clk_info **clocksp)
405 {
406 	struct tegra_bpmp_clk_info *clocks;
407 	unsigned int max_id, id, count = 0;
408 	unsigned int holes = 0;
409 	int err;
410 
411 	err = tegra_bpmp_clk_get_max_id(bpmp);
412 	if (err < 0)
413 		return err;
414 
415 	max_id = err;
416 
417 	dev_dbg(bpmp->dev, "maximum clock ID: %u\n", max_id);
418 
419 	clocks = kcalloc(max_id + 1, sizeof(*clocks), GFP_KERNEL);
420 	if (!clocks)
421 		return -ENOMEM;
422 
423 	for (id = 0; id <= max_id; id++) {
424 		struct tegra_bpmp_clk_info *info = &clocks[count];
425 
426 		err = tegra_bpmp_clk_get_info(bpmp, id, info);
427 		if (err < 0)
428 			continue;
429 
430 		if (info->num_parents >= U8_MAX) {
431 			dev_err(bpmp->dev,
432 				"clock %u has too many parents (%u, max: %u)\n",
433 				id, info->num_parents, U8_MAX);
434 			continue;
435 		}
436 
437 		/* clock not exposed by BPMP */
438 		if (info->name[0] == '\0') {
439 			holes++;
440 			continue;
441 		}
442 
443 		info->id = id;
444 		count++;
445 
446 		if (TEGRA_BPMP_DUMP_CLOCK_INFO)
447 			tegra_bpmp_clk_info_dump(bpmp, KERN_DEBUG, info);
448 	}
449 
450 	dev_dbg(bpmp->dev, "holes: %u\n", holes);
451 	*clocksp = clocks;
452 
453 	return count;
454 }
455 
456 static unsigned int
457 tegra_bpmp_clk_id_to_index(const struct tegra_bpmp_clk_info *clocks,
458 			   unsigned int num_clocks, unsigned int id)
459 {
460 	unsigned int i;
461 
462 	for (i = 0; i < num_clocks; i++)
463 		if (clocks[i].id == id)
464 			return i;
465 
466 	return UINT_MAX;
467 }
468 
469 static const struct tegra_bpmp_clk_info *
470 tegra_bpmp_clk_find(const struct tegra_bpmp_clk_info *clocks,
471 		    unsigned int num_clocks, unsigned int id)
472 {
473 	unsigned int i;
474 
475 	i = tegra_bpmp_clk_id_to_index(clocks, num_clocks, id);
476 
477 	if (i < num_clocks)
478 		return &clocks[i];
479 
480 	return NULL;
481 }
482 
483 static struct tegra_bpmp_clk *
484 tegra_bpmp_clk_register(struct tegra_bpmp *bpmp,
485 			const struct tegra_bpmp_clk_info *info,
486 			const struct tegra_bpmp_clk_info *clocks,
487 			unsigned int num_clocks)
488 {
489 	struct tegra_bpmp_clk *clk;
490 	struct clk_init_data init;
491 	const char **parents;
492 	unsigned int i;
493 	int err;
494 
495 	clk = devm_kzalloc(bpmp->dev, sizeof(*clk), GFP_KERNEL);
496 	if (!clk)
497 		return ERR_PTR(-ENOMEM);
498 
499 	clk->id = info->id;
500 	clk->bpmp = bpmp;
501 
502 	clk->parents = devm_kcalloc(bpmp->dev, info->num_parents,
503 				    sizeof(*clk->parents), GFP_KERNEL);
504 	if (!clk->parents)
505 		return ERR_PTR(-ENOMEM);
506 
507 	clk->num_parents = info->num_parents;
508 
509 	/* hardware clock initialization */
510 	memset(&init, 0, sizeof(init));
511 	init.name = info->name;
512 	clk->hw.init = &init;
513 
514 	if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
515 		if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
516 			init.ops = &tegra_bpmp_clk_mux_rate_ops;
517 		else
518 			init.ops = &tegra_bpmp_clk_mux_ops;
519 	} else {
520 		if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
521 			init.ops = &tegra_bpmp_clk_rate_ops;
522 		else
523 			init.ops = &tegra_bpmp_clk_gate_ops;
524 	}
525 
526 	init.num_parents = info->num_parents;
527 
528 	parents = kcalloc(info->num_parents, sizeof(*parents), GFP_KERNEL);
529 	if (!parents)
530 		return ERR_PTR(-ENOMEM);
531 
532 	for (i = 0; i < info->num_parents; i++) {
533 		const struct tegra_bpmp_clk_info *parent;
534 
535 		/* keep a private copy of the ID to parent index map */
536 		clk->parents[i] = info->parents[i];
537 
538 		parent = tegra_bpmp_clk_find(clocks, num_clocks,
539 					     info->parents[i]);
540 		if (!parent) {
541 			dev_err(bpmp->dev, "no parent %u found for %u\n",
542 				info->parents[i], info->id);
543 			continue;
544 		}
545 
546 		parents[i] = parent->name;
547 	}
548 
549 	init.parent_names = parents;
550 
551 	err = devm_clk_hw_register(bpmp->dev, &clk->hw);
552 
553 	kfree(parents);
554 
555 	if (err < 0)
556 		return ERR_PTR(err);
557 
558 	return clk;
559 }
560 
561 static void tegra_bpmp_register_clocks_one(struct tegra_bpmp *bpmp,
562 					   struct tegra_bpmp_clk_info *infos,
563 					   unsigned int i,
564 					   unsigned int count)
565 {
566 	unsigned int j;
567 	struct tegra_bpmp_clk_info *info;
568 	struct tegra_bpmp_clk *clk;
569 
570 	if (bpmp->clocks[i]) {
571 		/* already registered */
572 		return;
573 	}
574 
575 	info = &infos[i];
576 	for (j = 0; j < info->num_parents; ++j) {
577 		unsigned int p_id = info->parents[j];
578 		unsigned int p_i = tegra_bpmp_clk_id_to_index(infos, count,
579 							      p_id);
580 		if (p_i < count)
581 			tegra_bpmp_register_clocks_one(bpmp, infos, p_i, count);
582 	}
583 
584 	clk = tegra_bpmp_clk_register(bpmp, info, infos, count);
585 	if (IS_ERR(clk)) {
586 		dev_err(bpmp->dev,
587 			"failed to register clock %u (%s): %ld\n",
588 			info->id, info->name, PTR_ERR(clk));
589 		/* intentionally store the error pointer to
590 		 * bpmp->clocks[i] to avoid re-attempting the
591 		 * registration later
592 		 */
593 	}
594 
595 	bpmp->clocks[i] = clk;
596 }
597 
598 static int tegra_bpmp_register_clocks(struct tegra_bpmp *bpmp,
599 				      struct tegra_bpmp_clk_info *infos,
600 				      unsigned int count)
601 {
602 	unsigned int i;
603 
604 	bpmp->num_clocks = count;
605 
606 	bpmp->clocks = devm_kcalloc(bpmp->dev, count, sizeof(struct tegra_bpmp_clk), GFP_KERNEL);
607 	if (!bpmp->clocks)
608 		return -ENOMEM;
609 
610 	for (i = 0; i < count; i++) {
611 		tegra_bpmp_register_clocks_one(bpmp, infos, i, count);
612 	}
613 
614 	return 0;
615 }
616 
617 static void tegra_bpmp_unregister_clocks(struct tegra_bpmp *bpmp)
618 {
619 	unsigned int i;
620 
621 	for (i = 0; i < bpmp->num_clocks; i++)
622 		clk_hw_unregister(&bpmp->clocks[i]->hw);
623 }
624 
625 static struct clk_hw *tegra_bpmp_clk_of_xlate(struct of_phandle_args *clkspec,
626 					      void *data)
627 {
628 	unsigned int id = clkspec->args[0], i;
629 	struct tegra_bpmp *bpmp = data;
630 
631 	for (i = 0; i < bpmp->num_clocks; i++) {
632 		struct tegra_bpmp_clk *clk = bpmp->clocks[i];
633 
634 		if (!clk)
635 			continue;
636 
637 		if (clk->id == id)
638 			return &clk->hw;
639 	}
640 
641 	return NULL;
642 }
643 
644 int tegra_bpmp_init_clocks(struct tegra_bpmp *bpmp)
645 {
646 	struct tegra_bpmp_clk_info *clocks;
647 	unsigned int count;
648 	int err;
649 
650 	err = tegra_bpmp_probe_clocks(bpmp, &clocks);
651 	if (err < 0)
652 		return err;
653 
654 	count = err;
655 
656 	dev_dbg(bpmp->dev, "%u clocks probed\n", count);
657 
658 	err = tegra_bpmp_register_clocks(bpmp, clocks, count);
659 	if (err < 0)
660 		goto free;
661 
662 	err = of_clk_add_hw_provider(bpmp->dev->of_node,
663 				     tegra_bpmp_clk_of_xlate,
664 				     bpmp);
665 	if (err < 0) {
666 		tegra_bpmp_unregister_clocks(bpmp);
667 		goto free;
668 	}
669 
670 free:
671 	kfree(clocks);
672 	return err;
673 }
674