xref: /openbmc/linux/drivers/clk/tegra/clk-bpmp.c (revision 82e6fdd6)
1 /*
2  * Copyright (C) 2016 NVIDIA Corporation
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 version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/clk-provider.h>
10 #include <linux/device.h>
11 #include <linux/seq_buf.h>
12 #include <linux/slab.h>
13 
14 #include <soc/tegra/bpmp.h>
15 #include <soc/tegra/bpmp-abi.h>
16 
17 #define TEGRA_BPMP_DUMP_CLOCK_INFO	0
18 
19 #define TEGRA_BPMP_CLK_HAS_MUX		BIT(0)
20 #define TEGRA_BPMP_CLK_HAS_SET_RATE	BIT(1)
21 #define TEGRA_BPMP_CLK_IS_ROOT		BIT(2)
22 
23 struct tegra_bpmp_clk_info {
24 	unsigned int id;
25 	char name[MRQ_CLK_NAME_MAXLEN];
26 	unsigned int parents[MRQ_CLK_MAX_PARENTS];
27 	unsigned int num_parents;
28 	unsigned long flags;
29 };
30 
31 struct tegra_bpmp_clk {
32 	struct clk_hw hw;
33 
34 	struct tegra_bpmp *bpmp;
35 	unsigned int id;
36 
37 	unsigned int num_parents;
38 	unsigned int *parents;
39 };
40 
41 static inline struct tegra_bpmp_clk *to_tegra_bpmp_clk(struct clk_hw *hw)
42 {
43 	return container_of(hw, struct tegra_bpmp_clk, hw);
44 }
45 
46 struct tegra_bpmp_clk_message {
47 	unsigned int cmd;
48 	unsigned int id;
49 
50 	struct {
51 		const void *data;
52 		size_t size;
53 	} tx;
54 
55 	struct {
56 		void *data;
57 		size_t size;
58 		int ret;
59 	} rx;
60 };
61 
62 static int tegra_bpmp_clk_transfer(struct tegra_bpmp *bpmp,
63 				   const struct tegra_bpmp_clk_message *clk)
64 {
65 	struct mrq_clk_request request;
66 	struct tegra_bpmp_message msg;
67 	void *req = &request;
68 	int err;
69 
70 	memset(&request, 0, sizeof(request));
71 	request.cmd_and_id = (clk->cmd << 24) | clk->id;
72 
73 	/*
74 	 * The mrq_clk_request structure has an anonymous union at offset 4
75 	 * that contains all possible sub-command structures. Copy the data
76 	 * to that union. Ideally we'd be able to refer to it by name, but
77 	 * doing so would require changing the ABI header and increase the
78 	 * maintenance burden.
79 	 */
80 	memcpy(req + 4, clk->tx.data, clk->tx.size);
81 
82 	memset(&msg, 0, sizeof(msg));
83 	msg.mrq = MRQ_CLK;
84 	msg.tx.data = &request;
85 	msg.tx.size = sizeof(request);
86 	msg.rx.data = clk->rx.data;
87 	msg.rx.size = clk->rx.size;
88 
89 	err = tegra_bpmp_transfer(bpmp, &msg);
90 	if (err < 0)
91 		return err;
92 	else if (msg.rx.ret < 0)
93 		return -EINVAL;
94 
95 	return 0;
96 }
97 
98 static int tegra_bpmp_clk_prepare(struct clk_hw *hw)
99 {
100 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
101 	struct tegra_bpmp_clk_message msg;
102 
103 	memset(&msg, 0, sizeof(msg));
104 	msg.cmd = CMD_CLK_ENABLE;
105 	msg.id = clk->id;
106 
107 	return tegra_bpmp_clk_transfer(clk->bpmp, &msg);
108 }
109 
110 static void tegra_bpmp_clk_unprepare(struct clk_hw *hw)
111 {
112 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
113 	struct tegra_bpmp_clk_message msg;
114 	int err;
115 
116 	memset(&msg, 0, sizeof(msg));
117 	msg.cmd = CMD_CLK_DISABLE;
118 	msg.id = clk->id;
119 
120 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
121 	if (err < 0)
122 		dev_err(clk->bpmp->dev, "failed to disable clock %s: %d\n",
123 			clk_hw_get_name(hw), err);
124 }
125 
126 static int tegra_bpmp_clk_is_prepared(struct clk_hw *hw)
127 {
128 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
129 	struct cmd_clk_is_enabled_response response;
130 	struct tegra_bpmp_clk_message msg;
131 	int err;
132 
133 	memset(&msg, 0, sizeof(msg));
134 	msg.cmd = CMD_CLK_IS_ENABLED;
135 	msg.id = clk->id;
136 	msg.rx.data = &response;
137 	msg.rx.size = sizeof(response);
138 
139 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
140 	if (err < 0)
141 		return err;
142 
143 	return response.state;
144 }
145 
146 static unsigned long tegra_bpmp_clk_recalc_rate(struct clk_hw *hw,
147 						unsigned long parent_rate)
148 {
149 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
150 	struct cmd_clk_get_rate_response response;
151 	struct cmd_clk_get_rate_request request;
152 	struct tegra_bpmp_clk_message msg;
153 	int err;
154 
155 	memset(&msg, 0, sizeof(msg));
156 	msg.cmd = CMD_CLK_GET_RATE;
157 	msg.id = clk->id;
158 	msg.tx.data = &request;
159 	msg.tx.size = sizeof(request);
160 	msg.rx.data = &response;
161 	msg.rx.size = sizeof(response);
162 
163 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
164 	if (err < 0)
165 		return err;
166 
167 	return response.rate;
168 }
169 
170 static long tegra_bpmp_clk_round_rate(struct clk_hw *hw, unsigned long rate,
171 				      unsigned long *parent_rate)
172 {
173 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
174 	struct cmd_clk_round_rate_response response;
175 	struct cmd_clk_round_rate_request request;
176 	struct tegra_bpmp_clk_message msg;
177 	int err;
178 
179 	memset(&request, 0, sizeof(request));
180 	request.rate = rate;
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 	return response.rate;
195 }
196 
197 static int tegra_bpmp_clk_set_parent(struct clk_hw *hw, u8 index)
198 {
199 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
200 	struct cmd_clk_set_parent_response response;
201 	struct cmd_clk_set_parent_request request;
202 	struct tegra_bpmp_clk_message msg;
203 	int err;
204 
205 	memset(&request, 0, sizeof(request));
206 	request.parent_id = clk->parents[index];
207 
208 	memset(&msg, 0, sizeof(msg));
209 	msg.cmd = CMD_CLK_SET_PARENT;
210 	msg.id = clk->id;
211 	msg.tx.data = &request;
212 	msg.tx.size = sizeof(request);
213 	msg.rx.data = &response;
214 	msg.rx.size = sizeof(response);
215 
216 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
217 	if (err < 0)
218 		return err;
219 
220 	/* XXX check parent ID in response */
221 
222 	return 0;
223 }
224 
225 static u8 tegra_bpmp_clk_get_parent(struct clk_hw *hw)
226 {
227 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
228 	struct cmd_clk_get_parent_response response;
229 	struct tegra_bpmp_clk_message msg;
230 	unsigned int i;
231 	int err;
232 
233 	memset(&msg, 0, sizeof(msg));
234 	msg.cmd = CMD_CLK_GET_PARENT;
235 	msg.id = clk->id;
236 	msg.rx.data = &response;
237 	msg.rx.size = sizeof(response);
238 
239 	err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
240 	if (err < 0) {
241 		dev_err(clk->bpmp->dev, "failed to get parent for %s: %d\n",
242 			clk_hw_get_name(hw), err);
243 		return U8_MAX;
244 	}
245 
246 	for (i = 0; i < clk->num_parents; i++)
247 		if (clk->parents[i] == response.parent_id)
248 			return i;
249 
250 	return U8_MAX;
251 }
252 
253 static int tegra_bpmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
254 				   unsigned long parent_rate)
255 {
256 	struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
257 	struct cmd_clk_set_rate_response response;
258 	struct cmd_clk_set_rate_request request;
259 	struct tegra_bpmp_clk_message msg;
260 
261 	memset(&request, 0, sizeof(request));
262 	request.rate = rate;
263 
264 	memset(&msg, 0, sizeof(msg));
265 	msg.cmd = CMD_CLK_SET_RATE;
266 	msg.id = clk->id;
267 	msg.tx.data = &request;
268 	msg.tx.size = sizeof(request);
269 	msg.rx.data = &response;
270 	msg.rx.size = sizeof(response);
271 
272 	return tegra_bpmp_clk_transfer(clk->bpmp, &msg);
273 }
274 
275 static const struct clk_ops tegra_bpmp_clk_gate_ops = {
276 	.prepare = tegra_bpmp_clk_prepare,
277 	.unprepare = tegra_bpmp_clk_unprepare,
278 	.is_prepared = tegra_bpmp_clk_is_prepared,
279 	.recalc_rate = tegra_bpmp_clk_recalc_rate,
280 };
281 
282 static const struct clk_ops tegra_bpmp_clk_mux_ops = {
283 	.prepare = tegra_bpmp_clk_prepare,
284 	.unprepare = tegra_bpmp_clk_unprepare,
285 	.is_prepared = tegra_bpmp_clk_is_prepared,
286 	.recalc_rate = tegra_bpmp_clk_recalc_rate,
287 	.set_parent = tegra_bpmp_clk_set_parent,
288 	.get_parent = tegra_bpmp_clk_get_parent,
289 };
290 
291 static const struct clk_ops tegra_bpmp_clk_rate_ops = {
292 	.prepare = tegra_bpmp_clk_prepare,
293 	.unprepare = tegra_bpmp_clk_unprepare,
294 	.is_prepared = tegra_bpmp_clk_is_prepared,
295 	.recalc_rate = tegra_bpmp_clk_recalc_rate,
296 	.round_rate = tegra_bpmp_clk_round_rate,
297 	.set_rate = tegra_bpmp_clk_set_rate,
298 };
299 
300 static const struct clk_ops tegra_bpmp_clk_mux_rate_ops = {
301 	.prepare = tegra_bpmp_clk_prepare,
302 	.unprepare = tegra_bpmp_clk_unprepare,
303 	.is_prepared = tegra_bpmp_clk_is_prepared,
304 	.recalc_rate = tegra_bpmp_clk_recalc_rate,
305 	.round_rate = tegra_bpmp_clk_round_rate,
306 	.set_parent = tegra_bpmp_clk_set_parent,
307 	.get_parent = tegra_bpmp_clk_get_parent,
308 	.set_rate = tegra_bpmp_clk_set_rate,
309 };
310 
311 static int tegra_bpmp_clk_get_max_id(struct tegra_bpmp *bpmp)
312 {
313 	struct cmd_clk_get_max_clk_id_response response;
314 	struct tegra_bpmp_clk_message msg;
315 	int err;
316 
317 	memset(&msg, 0, sizeof(msg));
318 	msg.cmd = CMD_CLK_GET_MAX_CLK_ID;
319 	msg.rx.data = &response;
320 	msg.rx.size = sizeof(response);
321 
322 	err = tegra_bpmp_clk_transfer(bpmp, &msg);
323 	if (err < 0)
324 		return err;
325 
326 	if (response.max_id > INT_MAX)
327 		return -E2BIG;
328 
329 	return response.max_id;
330 }
331 
332 static int tegra_bpmp_clk_get_info(struct tegra_bpmp *bpmp, unsigned int id,
333 				   struct tegra_bpmp_clk_info *info)
334 {
335 	struct cmd_clk_get_all_info_response response;
336 	struct tegra_bpmp_clk_message msg;
337 	unsigned int i;
338 	int err;
339 
340 	memset(&msg, 0, sizeof(msg));
341 	msg.cmd = CMD_CLK_GET_ALL_INFO;
342 	msg.id = id;
343 	msg.rx.data = &response;
344 	msg.rx.size = sizeof(response);
345 
346 	err = tegra_bpmp_clk_transfer(bpmp, &msg);
347 	if (err < 0)
348 		return err;
349 
350 	strlcpy(info->name, response.name, MRQ_CLK_NAME_MAXLEN);
351 	info->num_parents = response.num_parents;
352 
353 	for (i = 0; i < info->num_parents; i++)
354 		info->parents[i] = response.parents[i];
355 
356 	info->flags = response.flags;
357 
358 	return 0;
359 }
360 
361 static void tegra_bpmp_clk_info_dump(struct tegra_bpmp *bpmp,
362 				     const char *level,
363 				     const struct tegra_bpmp_clk_info *info)
364 {
365 	const char *prefix = "";
366 	struct seq_buf buf;
367 	unsigned int i;
368 	char flags[64];
369 
370 	seq_buf_init(&buf, flags, sizeof(flags));
371 
372 	if (info->flags)
373 		seq_buf_printf(&buf, "(");
374 
375 	if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
376 		seq_buf_printf(&buf, "%smux", prefix);
377 		prefix = ", ";
378 	}
379 
380 	if ((info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE) == 0) {
381 		seq_buf_printf(&buf, "%sfixed", prefix);
382 		prefix = ", ";
383 	}
384 
385 	if (info->flags & TEGRA_BPMP_CLK_IS_ROOT) {
386 		seq_buf_printf(&buf, "%sroot", prefix);
387 		prefix = ", ";
388 	}
389 
390 	if (info->flags)
391 		seq_buf_printf(&buf, ")");
392 
393 	dev_printk(level, bpmp->dev, "%03u: %s\n", info->id, info->name);
394 	dev_printk(level, bpmp->dev, "  flags: %lx %s\n", info->flags, flags);
395 	dev_printk(level, bpmp->dev, "  parents: %u\n", info->num_parents);
396 
397 	for (i = 0; i < info->num_parents; i++)
398 		dev_printk(level, bpmp->dev, "    %03u\n", info->parents[i]);
399 }
400 
401 static int tegra_bpmp_probe_clocks(struct tegra_bpmp *bpmp,
402 				   struct tegra_bpmp_clk_info **clocksp)
403 {
404 	struct tegra_bpmp_clk_info *clocks;
405 	unsigned int max_id, id, count = 0;
406 	unsigned int holes = 0;
407 	int err;
408 
409 	err = tegra_bpmp_clk_get_max_id(bpmp);
410 	if (err < 0)
411 		return err;
412 
413 	max_id = err;
414 
415 	dev_dbg(bpmp->dev, "maximum clock ID: %u\n", max_id);
416 
417 	clocks = kcalloc(max_id + 1, sizeof(*clocks), GFP_KERNEL);
418 	if (!clocks)
419 		return -ENOMEM;
420 
421 	for (id = 0; id <= max_id; id++) {
422 		struct tegra_bpmp_clk_info *info = &clocks[count];
423 
424 		err = tegra_bpmp_clk_get_info(bpmp, id, info);
425 		if (err < 0)
426 			continue;
427 
428 		if (info->num_parents >= U8_MAX) {
429 			dev_err(bpmp->dev,
430 				"clock %u has too many parents (%u, max: %u)\n",
431 				id, info->num_parents, U8_MAX);
432 			continue;
433 		}
434 
435 		/* clock not exposed by BPMP */
436 		if (info->name[0] == '\0') {
437 			holes++;
438 			continue;
439 		}
440 
441 		info->id = id;
442 		count++;
443 
444 		if (TEGRA_BPMP_DUMP_CLOCK_INFO)
445 			tegra_bpmp_clk_info_dump(bpmp, KERN_DEBUG, info);
446 	}
447 
448 	dev_dbg(bpmp->dev, "holes: %u\n", holes);
449 	*clocksp = clocks;
450 
451 	return count;
452 }
453 
454 static const struct tegra_bpmp_clk_info *
455 tegra_bpmp_clk_find(const struct tegra_bpmp_clk_info *clocks,
456 		    unsigned int num_clocks, unsigned int id)
457 {
458 	unsigned int i;
459 
460 	for (i = 0; i < num_clocks; i++)
461 		if (clocks[i].id == id)
462 			return &clocks[i];
463 
464 	return NULL;
465 }
466 
467 static struct tegra_bpmp_clk *
468 tegra_bpmp_clk_register(struct tegra_bpmp *bpmp,
469 			const struct tegra_bpmp_clk_info *info,
470 			const struct tegra_bpmp_clk_info *clocks,
471 			unsigned int num_clocks)
472 {
473 	struct tegra_bpmp_clk *clk;
474 	struct clk_init_data init;
475 	const char **parents;
476 	unsigned int i;
477 	int err;
478 
479 	clk = devm_kzalloc(bpmp->dev, sizeof(*clk), GFP_KERNEL);
480 	if (!clk)
481 		return ERR_PTR(-ENOMEM);
482 
483 	clk->id = info->id;
484 	clk->bpmp = bpmp;
485 
486 	clk->parents = devm_kcalloc(bpmp->dev, info->num_parents,
487 				    sizeof(*clk->parents), GFP_KERNEL);
488 	if (!clk->parents)
489 		return ERR_PTR(-ENOMEM);
490 
491 	clk->num_parents = info->num_parents;
492 
493 	/* hardware clock initialization */
494 	memset(&init, 0, sizeof(init));
495 	init.name = info->name;
496 	clk->hw.init = &init;
497 
498 	if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
499 		if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
500 			init.ops = &tegra_bpmp_clk_mux_rate_ops;
501 		else
502 			init.ops = &tegra_bpmp_clk_mux_ops;
503 	} else {
504 		if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
505 			init.ops = &tegra_bpmp_clk_rate_ops;
506 		else
507 			init.ops = &tegra_bpmp_clk_gate_ops;
508 	}
509 
510 	init.num_parents = info->num_parents;
511 
512 	parents = kcalloc(info->num_parents, sizeof(*parents), GFP_KERNEL);
513 	if (!parents)
514 		return ERR_PTR(-ENOMEM);
515 
516 	for (i = 0; i < info->num_parents; i++) {
517 		const struct tegra_bpmp_clk_info *parent;
518 
519 		/* keep a private copy of the ID to parent index map */
520 		clk->parents[i] = info->parents[i];
521 
522 		parent = tegra_bpmp_clk_find(clocks, num_clocks,
523 					     info->parents[i]);
524 		if (!parent) {
525 			dev_err(bpmp->dev, "no parent %u found for %u\n",
526 				info->parents[i], info->id);
527 			continue;
528 		}
529 
530 		parents[i] = parent->name;
531 	}
532 
533 	init.parent_names = parents;
534 
535 	err = devm_clk_hw_register(bpmp->dev, &clk->hw);
536 
537 	kfree(parents);
538 
539 	if (err < 0)
540 		return ERR_PTR(err);
541 
542 	return clk;
543 }
544 
545 static int tegra_bpmp_register_clocks(struct tegra_bpmp *bpmp,
546 				      struct tegra_bpmp_clk_info *infos,
547 				      unsigned int count)
548 {
549 	struct tegra_bpmp_clk *clk;
550 	unsigned int i;
551 
552 	bpmp->num_clocks = count;
553 
554 	bpmp->clocks = devm_kcalloc(bpmp->dev, count, sizeof(clk), GFP_KERNEL);
555 	if (!bpmp->clocks)
556 		return -ENOMEM;
557 
558 	for (i = 0; i < count; i++) {
559 		struct tegra_bpmp_clk_info *info = &infos[i];
560 
561 		clk = tegra_bpmp_clk_register(bpmp, info, infos, count);
562 		if (IS_ERR(clk)) {
563 			dev_err(bpmp->dev,
564 				"failed to register clock %u (%s): %ld\n",
565 				info->id, info->name, PTR_ERR(clk));
566 			continue;
567 		}
568 
569 		bpmp->clocks[i] = clk;
570 	}
571 
572 	return 0;
573 }
574 
575 static void tegra_bpmp_unregister_clocks(struct tegra_bpmp *bpmp)
576 {
577 	unsigned int i;
578 
579 	for (i = 0; i < bpmp->num_clocks; i++)
580 		clk_hw_unregister(&bpmp->clocks[i]->hw);
581 }
582 
583 static struct clk_hw *tegra_bpmp_clk_of_xlate(struct of_phandle_args *clkspec,
584 					      void *data)
585 {
586 	unsigned int id = clkspec->args[0], i;
587 	struct tegra_bpmp *bpmp = data;
588 
589 	for (i = 0; i < bpmp->num_clocks; i++)
590 		if (bpmp->clocks[i]->id == id)
591 			return &bpmp->clocks[i]->hw;
592 
593 	return NULL;
594 }
595 
596 int tegra_bpmp_init_clocks(struct tegra_bpmp *bpmp)
597 {
598 	struct tegra_bpmp_clk_info *clocks;
599 	unsigned int count;
600 	int err;
601 
602 	err = tegra_bpmp_probe_clocks(bpmp, &clocks);
603 	if (err < 0)
604 		return err;
605 
606 	count = err;
607 
608 	dev_dbg(bpmp->dev, "%u clocks probed\n", count);
609 
610 	err = tegra_bpmp_register_clocks(bpmp, clocks, count);
611 	if (err < 0)
612 		goto free;
613 
614 	err = of_clk_add_hw_provider(bpmp->dev->of_node,
615 				     tegra_bpmp_clk_of_xlate,
616 				     bpmp);
617 	if (err < 0) {
618 		tegra_bpmp_unregister_clocks(bpmp);
619 		goto free;
620 	}
621 
622 free:
623 	kfree(clocks);
624 	return err;
625 }
626