xref: /openbmc/linux/drivers/clk/clk-composite.c (revision 5d37a119) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2013 NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/device.h>
8 #include <linux/err.h>
9 #include <linux/slab.h>
10 
11 static u8 clk_composite_get_parent(struct clk_hw *hw)
12 {
13 	struct clk_composite *composite = to_clk_composite(hw);
14 	const struct clk_ops *mux_ops = composite->mux_ops;
15 	struct clk_hw *mux_hw = composite->mux_hw;
16 
17 	__clk_hw_set_clk(mux_hw, hw);
18 
19 	return mux_ops->get_parent(mux_hw);
20 }
21 
22 static int clk_composite_set_parent(struct clk_hw *hw, u8 index)
23 {
24 	struct clk_composite *composite = to_clk_composite(hw);
25 	const struct clk_ops *mux_ops = composite->mux_ops;
26 	struct clk_hw *mux_hw = composite->mux_hw;
27 
28 	__clk_hw_set_clk(mux_hw, hw);
29 
30 	return mux_ops->set_parent(mux_hw, index);
31 }
32 
33 static unsigned long clk_composite_recalc_rate(struct clk_hw *hw,
34 					    unsigned long parent_rate)
35 {
36 	struct clk_composite *composite = to_clk_composite(hw);
37 	const struct clk_ops *rate_ops = composite->rate_ops;
38 	struct clk_hw *rate_hw = composite->rate_hw;
39 
40 	__clk_hw_set_clk(rate_hw, hw);
41 
42 	return rate_ops->recalc_rate(rate_hw, parent_rate);
43 }
44 
45 static int clk_composite_determine_rate_for_parent(struct clk_hw *rate_hw,
46 						   struct clk_rate_request *req,
47 						   struct clk_hw *parent_hw,
48 						   const struct clk_ops *rate_ops)
49 {
50 	long rate;
51 
52 	req->best_parent_hw = parent_hw;
53 	req->best_parent_rate = clk_hw_get_rate(parent_hw);
54 
55 	if (rate_ops->determine_rate)
56 		return rate_ops->determine_rate(rate_hw, req);
57 
58 	rate = rate_ops->round_rate(rate_hw, req->rate,
59 				    &req->best_parent_rate);
60 	if (rate < 0)
61 		return rate;
62 
63 	req->rate = rate;
64 
65 	return 0;
66 }
67 
68 static int clk_composite_determine_rate(struct clk_hw *hw,
69 					struct clk_rate_request *req)
70 {
71 	struct clk_composite *composite = to_clk_composite(hw);
72 	const struct clk_ops *rate_ops = composite->rate_ops;
73 	const struct clk_ops *mux_ops = composite->mux_ops;
74 	struct clk_hw *rate_hw = composite->rate_hw;
75 	struct clk_hw *mux_hw = composite->mux_hw;
76 	struct clk_hw *parent;
77 	unsigned long rate_diff;
78 	unsigned long best_rate_diff = ULONG_MAX;
79 	unsigned long best_rate = 0;
80 	int i, ret;
81 
82 	if (rate_hw && rate_ops &&
83 	    (rate_ops->determine_rate || rate_ops->round_rate) &&
84 	    mux_hw && mux_ops && mux_ops->set_parent) {
85 		req->best_parent_hw = NULL;
86 
87 		if (clk_hw_get_flags(hw) & CLK_SET_RATE_NO_REPARENT) {
88 			struct clk_rate_request tmp_req;
89 
90 			parent = clk_hw_get_parent(mux_hw);
91 
92 			clk_hw_forward_rate_request(hw, req, parent, &tmp_req, req->rate);
93 			ret = clk_composite_determine_rate_for_parent(rate_hw,
94 								      &tmp_req,
95 								      parent,
96 								      rate_ops);
97 			if (ret)
98 				return ret;
99 
100 			req->rate = tmp_req.rate;
101 			req->best_parent_hw = tmp_req.best_parent_hw;
102 			req->best_parent_rate = tmp_req.best_parent_rate;
103 
104 			return 0;
105 		}
106 
107 		for (i = 0; i < clk_hw_get_num_parents(mux_hw); i++) {
108 			struct clk_rate_request tmp_req;
109 
110 			parent = clk_hw_get_parent_by_index(mux_hw, i);
111 			if (!parent)
112 				continue;
113 
114 			clk_hw_forward_rate_request(hw, req, parent, &tmp_req, req->rate);
115 			ret = clk_composite_determine_rate_for_parent(rate_hw,
116 								      &tmp_req,
117 								      parent,
118 								      rate_ops);
119 			if (ret)
120 				continue;
121 
122 			if (req->rate >= tmp_req.rate)
123 				rate_diff = req->rate - tmp_req.rate;
124 			else
125 				rate_diff = tmp_req.rate - req->rate;
126 
127 			if (!rate_diff || !req->best_parent_hw
128 				       || best_rate_diff > rate_diff) {
129 				req->best_parent_hw = parent;
130 				req->best_parent_rate = tmp_req.best_parent_rate;
131 				best_rate_diff = rate_diff;
132 				best_rate = tmp_req.rate;
133 			}
134 
135 			if (!rate_diff)
136 				return 0;
137 		}
138 
139 		req->rate = best_rate;
140 		return 0;
141 	} else if (rate_hw && rate_ops && rate_ops->determine_rate) {
142 		__clk_hw_set_clk(rate_hw, hw);
143 		return rate_ops->determine_rate(rate_hw, req);
144 	} else if (mux_hw && mux_ops && mux_ops->determine_rate) {
145 		__clk_hw_set_clk(mux_hw, hw);
146 		return mux_ops->determine_rate(mux_hw, req);
147 	} else {
148 		pr_err("clk: clk_composite_determine_rate function called, but no mux or rate callback set!\n");
149 		return -EINVAL;
150 	}
151 }
152 
153 static long clk_composite_round_rate(struct clk_hw *hw, unsigned long rate,
154 				  unsigned long *prate)
155 {
156 	struct clk_composite *composite = to_clk_composite(hw);
157 	const struct clk_ops *rate_ops = composite->rate_ops;
158 	struct clk_hw *rate_hw = composite->rate_hw;
159 
160 	__clk_hw_set_clk(rate_hw, hw);
161 
162 	return rate_ops->round_rate(rate_hw, rate, prate);
163 }
164 
165 static int clk_composite_set_rate(struct clk_hw *hw, unsigned long rate,
166 			       unsigned long parent_rate)
167 {
168 	struct clk_composite *composite = to_clk_composite(hw);
169 	const struct clk_ops *rate_ops = composite->rate_ops;
170 	struct clk_hw *rate_hw = composite->rate_hw;
171 
172 	__clk_hw_set_clk(rate_hw, hw);
173 
174 	return rate_ops->set_rate(rate_hw, rate, parent_rate);
175 }
176 
177 static int clk_composite_set_rate_and_parent(struct clk_hw *hw,
178 					     unsigned long rate,
179 					     unsigned long parent_rate,
180 					     u8 index)
181 {
182 	struct clk_composite *composite = to_clk_composite(hw);
183 	const struct clk_ops *rate_ops = composite->rate_ops;
184 	const struct clk_ops *mux_ops = composite->mux_ops;
185 	struct clk_hw *rate_hw = composite->rate_hw;
186 	struct clk_hw *mux_hw = composite->mux_hw;
187 	unsigned long temp_rate;
188 
189 	__clk_hw_set_clk(rate_hw, hw);
190 	__clk_hw_set_clk(mux_hw, hw);
191 
192 	temp_rate = rate_ops->recalc_rate(rate_hw, parent_rate);
193 	if (temp_rate > rate) {
194 		rate_ops->set_rate(rate_hw, rate, parent_rate);
195 		mux_ops->set_parent(mux_hw, index);
196 	} else {
197 		mux_ops->set_parent(mux_hw, index);
198 		rate_ops->set_rate(rate_hw, rate, parent_rate);
199 	}
200 
201 	return 0;
202 }
203 
204 static int clk_composite_is_enabled(struct clk_hw *hw)
205 {
206 	struct clk_composite *composite = to_clk_composite(hw);
207 	const struct clk_ops *gate_ops = composite->gate_ops;
208 	struct clk_hw *gate_hw = composite->gate_hw;
209 
210 	__clk_hw_set_clk(gate_hw, hw);
211 
212 	return gate_ops->is_enabled(gate_hw);
213 }
214 
215 static int clk_composite_enable(struct clk_hw *hw)
216 {
217 	struct clk_composite *composite = to_clk_composite(hw);
218 	const struct clk_ops *gate_ops = composite->gate_ops;
219 	struct clk_hw *gate_hw = composite->gate_hw;
220 
221 	__clk_hw_set_clk(gate_hw, hw);
222 
223 	return gate_ops->enable(gate_hw);
224 }
225 
226 static void clk_composite_disable(struct clk_hw *hw)
227 {
228 	struct clk_composite *composite = to_clk_composite(hw);
229 	const struct clk_ops *gate_ops = composite->gate_ops;
230 	struct clk_hw *gate_hw = composite->gate_hw;
231 
232 	__clk_hw_set_clk(gate_hw, hw);
233 
234 	gate_ops->disable(gate_hw);
235 }
236 
237 static struct clk_hw *__clk_hw_register_composite(struct device *dev,
238 			const char *name, const char * const *parent_names,
239 			const struct clk_parent_data *pdata, int num_parents,
240 			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
241 			struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
242 			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
243 			unsigned long flags)
244 {
245 	struct clk_hw *hw;
246 	struct clk_init_data init = {};
247 	struct clk_composite *composite;
248 	struct clk_ops *clk_composite_ops;
249 	int ret;
250 
251 	composite = kzalloc(sizeof(*composite), GFP_KERNEL);
252 	if (!composite)
253 		return ERR_PTR(-ENOMEM);
254 
255 	init.name = name;
256 	init.flags = flags;
257 	if (parent_names)
258 		init.parent_names = parent_names;
259 	else
260 		init.parent_data = pdata;
261 	init.num_parents = num_parents;
262 	hw = &composite->hw;
263 
264 	clk_composite_ops = &composite->ops;
265 
266 	if (mux_hw && mux_ops) {
267 		if (!mux_ops->get_parent) {
268 			hw = ERR_PTR(-EINVAL);
269 			goto err;
270 		}
271 
272 		composite->mux_hw = mux_hw;
273 		composite->mux_ops = mux_ops;
274 		clk_composite_ops->get_parent = clk_composite_get_parent;
275 		if (mux_ops->set_parent)
276 			clk_composite_ops->set_parent = clk_composite_set_parent;
277 		if (mux_ops->determine_rate)
278 			clk_composite_ops->determine_rate = clk_composite_determine_rate;
279 	}
280 
281 	if (rate_hw && rate_ops) {
282 		if (!rate_ops->recalc_rate) {
283 			hw = ERR_PTR(-EINVAL);
284 			goto err;
285 		}
286 		clk_composite_ops->recalc_rate = clk_composite_recalc_rate;
287 
288 		if (rate_ops->determine_rate)
289 			clk_composite_ops->determine_rate =
290 				clk_composite_determine_rate;
291 		else if (rate_ops->round_rate)
292 			clk_composite_ops->round_rate =
293 				clk_composite_round_rate;
294 
295 		/* .set_rate requires either .round_rate or .determine_rate */
296 		if (rate_ops->set_rate) {
297 			if (rate_ops->determine_rate || rate_ops->round_rate)
298 				clk_composite_ops->set_rate =
299 						clk_composite_set_rate;
300 			else
301 				WARN(1, "%s: missing round_rate op is required\n",
302 						__func__);
303 		}
304 
305 		composite->rate_hw = rate_hw;
306 		composite->rate_ops = rate_ops;
307 	}
308 
309 	if (mux_hw && mux_ops && rate_hw && rate_ops) {
310 		if (mux_ops->set_parent && rate_ops->set_rate)
311 			clk_composite_ops->set_rate_and_parent =
312 			clk_composite_set_rate_and_parent;
313 	}
314 
315 	if (gate_hw && gate_ops) {
316 		if (!gate_ops->is_enabled || !gate_ops->enable ||
317 		    !gate_ops->disable) {
318 			hw = ERR_PTR(-EINVAL);
319 			goto err;
320 		}
321 
322 		composite->gate_hw = gate_hw;
323 		composite->gate_ops = gate_ops;
324 		clk_composite_ops->is_enabled = clk_composite_is_enabled;
325 		clk_composite_ops->enable = clk_composite_enable;
326 		clk_composite_ops->disable = clk_composite_disable;
327 	}
328 
329 	init.ops = clk_composite_ops;
330 	composite->hw.init = &init;
331 
332 	ret = clk_hw_register(dev, hw);
333 	if (ret) {
334 		hw = ERR_PTR(ret);
335 		goto err;
336 	}
337 
338 	if (composite->mux_hw)
339 		composite->mux_hw->clk = hw->clk;
340 
341 	if (composite->rate_hw)
342 		composite->rate_hw->clk = hw->clk;
343 
344 	if (composite->gate_hw)
345 		composite->gate_hw->clk = hw->clk;
346 
347 	return hw;
348 
349 err:
350 	kfree(composite);
351 	return hw;
352 }
353 
354 struct clk_hw *clk_hw_register_composite(struct device *dev, const char *name,
355 			const char * const *parent_names, int num_parents,
356 			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
357 			struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
358 			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
359 			unsigned long flags)
360 {
361 	return __clk_hw_register_composite(dev, name, parent_names, NULL,
362 					   num_parents, mux_hw, mux_ops,
363 					   rate_hw, rate_ops, gate_hw,
364 					   gate_ops, flags);
365 }
366 EXPORT_SYMBOL_GPL(clk_hw_register_composite);
367 
368 struct clk_hw *clk_hw_register_composite_pdata(struct device *dev,
369 			const char *name,
370 			const struct clk_parent_data *parent_data,
371 			int num_parents,
372 			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
373 			struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
374 			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
375 			unsigned long flags)
376 {
377 	return __clk_hw_register_composite(dev, name, NULL, parent_data,
378 					   num_parents, mux_hw, mux_ops,
379 					   rate_hw, rate_ops, gate_hw,
380 					   gate_ops, flags);
381 }
382 
383 struct clk *clk_register_composite(struct device *dev, const char *name,
384 			const char * const *parent_names, int num_parents,
385 			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
386 			struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
387 			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
388 			unsigned long flags)
389 {
390 	struct clk_hw *hw;
391 
392 	hw = clk_hw_register_composite(dev, name, parent_names, num_parents,
393 			mux_hw, mux_ops, rate_hw, rate_ops, gate_hw, gate_ops,
394 			flags);
395 	if (IS_ERR(hw))
396 		return ERR_CAST(hw);
397 	return hw->clk;
398 }
399 EXPORT_SYMBOL_GPL(clk_register_composite);
400 
401 struct clk *clk_register_composite_pdata(struct device *dev, const char *name,
402 			const struct clk_parent_data *parent_data,
403 			int num_parents,
404 			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
405 			struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
406 			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
407 			unsigned long flags)
408 {
409 	struct clk_hw *hw;
410 
411 	hw = clk_hw_register_composite_pdata(dev, name, parent_data,
412 			num_parents, mux_hw, mux_ops, rate_hw, rate_ops,
413 			gate_hw, gate_ops, flags);
414 	if (IS_ERR(hw))
415 		return ERR_CAST(hw);
416 	return hw->clk;
417 }
418 
419 void clk_unregister_composite(struct clk *clk)
420 {
421 	struct clk_composite *composite;
422 	struct clk_hw *hw;
423 
424 	hw = __clk_get_hw(clk);
425 	if (!hw)
426 		return;
427 
428 	composite = to_clk_composite(hw);
429 
430 	clk_unregister(clk);
431 	kfree(composite);
432 }
433 
434 void clk_hw_unregister_composite(struct clk_hw *hw)
435 {
436 	struct clk_composite *composite;
437 
438 	composite = to_clk_composite(hw);
439 
440 	clk_hw_unregister(hw);
441 	kfree(composite);
442 }
443 EXPORT_SYMBOL_GPL(clk_hw_unregister_composite);
444 
445 static void devm_clk_hw_release_composite(struct device *dev, void *res)
446 {
447 	clk_hw_unregister_composite(*(struct clk_hw **)res);
448 }
449 
450 static struct clk_hw *__devm_clk_hw_register_composite(struct device *dev,
451 			const char *name, const char * const *parent_names,
452 			const struct clk_parent_data *pdata, int num_parents,
453 			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
454 			struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
455 			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
456 			unsigned long flags)
457 {
458 	struct clk_hw **ptr, *hw;
459 
460 	ptr = devres_alloc(devm_clk_hw_release_composite, sizeof(*ptr),
461 			   GFP_KERNEL);
462 	if (!ptr)
463 		return ERR_PTR(-ENOMEM);
464 
465 	hw = __clk_hw_register_composite(dev, name, parent_names, pdata,
466 					 num_parents, mux_hw, mux_ops, rate_hw,
467 					 rate_ops, gate_hw, gate_ops, flags);
468 
469 	if (!IS_ERR(hw)) {
470 		*ptr = hw;
471 		devres_add(dev, ptr);
472 	} else {
473 		devres_free(ptr);
474 	}
475 
476 	return hw;
477 }
478 
479 struct clk_hw *devm_clk_hw_register_composite_pdata(struct device *dev,
480 			const char *name,
481 			const struct clk_parent_data *parent_data,
482 			int num_parents,
483 			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
484 			struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
485 			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
486 			unsigned long flags)
487 {
488 	return __devm_clk_hw_register_composite(dev, name, NULL, parent_data,
489 						num_parents, mux_hw, mux_ops,
490 						rate_hw, rate_ops, gate_hw,
491 						gate_ops, flags);
492 }
493