xref: /linux/drivers/dpll/dpll_core.c (revision 9112fc0109fc0037ac3b8b633a169e78b4e23ca1)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  dpll_core.c - DPLL subsystem kernel-space interface implementation.
4  *
5  *  Copyright (c) 2023 Meta Platforms, Inc. and affiliates
6  *  Copyright (c) 2023 Intel Corporation.
7  */
8 
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/device.h>
12 #include <linux/err.h>
13 #include <linux/slab.h>
14 #include <linux/string.h>
15 
16 #include "dpll_core.h"
17 #include "dpll_netlink.h"
18 
19 /* Mutex lock to protect DPLL subsystem devices and pins */
20 DEFINE_MUTEX(dpll_lock);
21 
22 DEFINE_XARRAY_FLAGS(dpll_device_xa, XA_FLAGS_ALLOC);
23 DEFINE_XARRAY_FLAGS(dpll_pin_xa, XA_FLAGS_ALLOC);
24 
25 static u32 dpll_device_xa_id;
26 static u32 dpll_pin_xa_id;
27 
28 #define ASSERT_DPLL_REGISTERED(d)	\
29 	WARN_ON_ONCE(!xa_get_mark(&dpll_device_xa, (d)->id, DPLL_REGISTERED))
30 #define ASSERT_DPLL_NOT_REGISTERED(d)	\
31 	WARN_ON_ONCE(xa_get_mark(&dpll_device_xa, (d)->id, DPLL_REGISTERED))
32 #define ASSERT_DPLL_PIN_REGISTERED(p) \
33 	WARN_ON_ONCE(!xa_get_mark(&dpll_pin_xa, (p)->id, DPLL_REGISTERED))
34 
35 struct dpll_device_registration {
36 	struct list_head list;
37 	const struct dpll_device_ops *ops;
38 	void *priv;
39 };
40 
41 struct dpll_pin_registration {
42 	struct list_head list;
43 	const struct dpll_pin_ops *ops;
44 	void *priv;
45 };
46 
47 struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
48 {
49 	return rcu_dereference_rtnl(dev->dpll_pin);
50 }
51 
52 struct dpll_device *dpll_device_get_by_id(int id)
53 {
54 	if (xa_get_mark(&dpll_device_xa, id, DPLL_REGISTERED))
55 		return xa_load(&dpll_device_xa, id);
56 
57 	return NULL;
58 }
59 
60 static struct dpll_pin_registration *
61 dpll_pin_registration_find(struct dpll_pin_ref *ref,
62 			   const struct dpll_pin_ops *ops, void *priv)
63 {
64 	struct dpll_pin_registration *reg;
65 
66 	list_for_each_entry(reg, &ref->registration_list, list) {
67 		if (reg->ops == ops && reg->priv == priv)
68 			return reg;
69 	}
70 	return NULL;
71 }
72 
73 static int
74 dpll_xa_ref_pin_add(struct xarray *xa_pins, struct dpll_pin *pin,
75 		    const struct dpll_pin_ops *ops, void *priv)
76 {
77 	struct dpll_pin_registration *reg;
78 	struct dpll_pin_ref *ref;
79 	bool ref_exists = false;
80 	unsigned long i;
81 	int ret;
82 
83 	xa_for_each(xa_pins, i, ref) {
84 		if (ref->pin != pin)
85 			continue;
86 		reg = dpll_pin_registration_find(ref, ops, priv);
87 		if (reg) {
88 			refcount_inc(&ref->refcount);
89 			return 0;
90 		}
91 		ref_exists = true;
92 		break;
93 	}
94 
95 	if (!ref_exists) {
96 		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
97 		if (!ref)
98 			return -ENOMEM;
99 		ref->pin = pin;
100 		INIT_LIST_HEAD(&ref->registration_list);
101 		ret = xa_insert(xa_pins, pin->pin_idx, ref, GFP_KERNEL);
102 		if (ret) {
103 			kfree(ref);
104 			return ret;
105 		}
106 		refcount_set(&ref->refcount, 1);
107 	}
108 
109 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
110 	if (!reg) {
111 		if (!ref_exists) {
112 			xa_erase(xa_pins, pin->pin_idx);
113 			kfree(ref);
114 		}
115 		return -ENOMEM;
116 	}
117 	reg->ops = ops;
118 	reg->priv = priv;
119 	if (ref_exists)
120 		refcount_inc(&ref->refcount);
121 	list_add_tail(&reg->list, &ref->registration_list);
122 
123 	return 0;
124 }
125 
126 static int dpll_xa_ref_pin_del(struct xarray *xa_pins, struct dpll_pin *pin,
127 			       const struct dpll_pin_ops *ops, void *priv)
128 {
129 	struct dpll_pin_registration *reg;
130 	struct dpll_pin_ref *ref;
131 	unsigned long i;
132 
133 	xa_for_each(xa_pins, i, ref) {
134 		if (ref->pin != pin)
135 			continue;
136 		reg = dpll_pin_registration_find(ref, ops, priv);
137 		if (WARN_ON(!reg))
138 			return -EINVAL;
139 		if (refcount_dec_and_test(&ref->refcount)) {
140 			list_del(&reg->list);
141 			kfree(reg);
142 			xa_erase(xa_pins, i);
143 			WARN_ON(!list_empty(&ref->registration_list));
144 			kfree(ref);
145 		}
146 		return 0;
147 	}
148 
149 	return -EINVAL;
150 }
151 
152 static int
153 dpll_xa_ref_dpll_add(struct xarray *xa_dplls, struct dpll_device *dpll,
154 		     const struct dpll_pin_ops *ops, void *priv)
155 {
156 	struct dpll_pin_registration *reg;
157 	struct dpll_pin_ref *ref;
158 	bool ref_exists = false;
159 	unsigned long i;
160 	int ret;
161 
162 	xa_for_each(xa_dplls, i, ref) {
163 		if (ref->dpll != dpll)
164 			continue;
165 		reg = dpll_pin_registration_find(ref, ops, priv);
166 		if (reg) {
167 			refcount_inc(&ref->refcount);
168 			return 0;
169 		}
170 		ref_exists = true;
171 		break;
172 	}
173 
174 	if (!ref_exists) {
175 		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
176 		if (!ref)
177 			return -ENOMEM;
178 		ref->dpll = dpll;
179 		INIT_LIST_HEAD(&ref->registration_list);
180 		ret = xa_insert(xa_dplls, dpll->id, ref, GFP_KERNEL);
181 		if (ret) {
182 			kfree(ref);
183 			return ret;
184 		}
185 		refcount_set(&ref->refcount, 1);
186 	}
187 
188 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
189 	if (!reg) {
190 		if (!ref_exists) {
191 			xa_erase(xa_dplls, dpll->id);
192 			kfree(ref);
193 		}
194 		return -ENOMEM;
195 	}
196 	reg->ops = ops;
197 	reg->priv = priv;
198 	if (ref_exists)
199 		refcount_inc(&ref->refcount);
200 	list_add_tail(&reg->list, &ref->registration_list);
201 
202 	return 0;
203 }
204 
205 static void
206 dpll_xa_ref_dpll_del(struct xarray *xa_dplls, struct dpll_device *dpll,
207 		     const struct dpll_pin_ops *ops, void *priv)
208 {
209 	struct dpll_pin_registration *reg;
210 	struct dpll_pin_ref *ref;
211 	unsigned long i;
212 
213 	xa_for_each(xa_dplls, i, ref) {
214 		if (ref->dpll != dpll)
215 			continue;
216 		reg = dpll_pin_registration_find(ref, ops, priv);
217 		if (WARN_ON(!reg))
218 			return;
219 		if (refcount_dec_and_test(&ref->refcount)) {
220 			list_del(&reg->list);
221 			kfree(reg);
222 			xa_erase(xa_dplls, i);
223 			WARN_ON(!list_empty(&ref->registration_list));
224 			kfree(ref);
225 		}
226 		return;
227 	}
228 }
229 
230 struct dpll_pin_ref *dpll_xa_ref_dpll_first(struct xarray *xa_refs)
231 {
232 	struct dpll_pin_ref *ref;
233 	unsigned long i = 0;
234 
235 	ref = xa_find(xa_refs, &i, ULONG_MAX, XA_PRESENT);
236 	WARN_ON(!ref);
237 	return ref;
238 }
239 
240 static struct dpll_device *
241 dpll_device_alloc(const u64 clock_id, u32 device_idx, struct module *module)
242 {
243 	struct dpll_device *dpll;
244 	int ret;
245 
246 	dpll = kzalloc(sizeof(*dpll), GFP_KERNEL);
247 	if (!dpll)
248 		return ERR_PTR(-ENOMEM);
249 	refcount_set(&dpll->refcount, 1);
250 	INIT_LIST_HEAD(&dpll->registration_list);
251 	dpll->device_idx = device_idx;
252 	dpll->clock_id = clock_id;
253 	dpll->module = module;
254 	ret = xa_alloc_cyclic(&dpll_device_xa, &dpll->id, dpll, xa_limit_32b,
255 			      &dpll_device_xa_id, GFP_KERNEL);
256 	if (ret < 0) {
257 		kfree(dpll);
258 		return ERR_PTR(ret);
259 	}
260 	xa_init_flags(&dpll->pin_refs, XA_FLAGS_ALLOC);
261 
262 	return dpll;
263 }
264 
265 /**
266  * dpll_device_get - find existing or create new dpll device
267  * @clock_id: clock_id of creator
268  * @device_idx: idx given by device driver
269  * @module: reference to registering module
270  *
271  * Get existing object of a dpll device, unique for given arguments.
272  * Create new if doesn't exist yet.
273  *
274  * Context: Acquires a lock (dpll_lock)
275  * Return:
276  * * valid dpll_device struct pointer if succeeded
277  * * ERR_PTR(X) - error
278  */
279 struct dpll_device *
280 dpll_device_get(u64 clock_id, u32 device_idx, struct module *module)
281 {
282 	struct dpll_device *dpll, *ret = NULL;
283 	unsigned long index;
284 
285 	mutex_lock(&dpll_lock);
286 	xa_for_each(&dpll_device_xa, index, dpll) {
287 		if (dpll->clock_id == clock_id &&
288 		    dpll->device_idx == device_idx &&
289 		    dpll->module == module) {
290 			ret = dpll;
291 			refcount_inc(&ret->refcount);
292 			break;
293 		}
294 	}
295 	if (!ret)
296 		ret = dpll_device_alloc(clock_id, device_idx, module);
297 	mutex_unlock(&dpll_lock);
298 
299 	return ret;
300 }
301 EXPORT_SYMBOL_GPL(dpll_device_get);
302 
303 /**
304  * dpll_device_put - decrease the refcount and free memory if possible
305  * @dpll: dpll_device struct pointer
306  *
307  * Context: Acquires a lock (dpll_lock)
308  * Drop reference for a dpll device, if all references are gone, delete
309  * dpll device object.
310  */
311 void dpll_device_put(struct dpll_device *dpll)
312 {
313 	mutex_lock(&dpll_lock);
314 	if (refcount_dec_and_test(&dpll->refcount)) {
315 		ASSERT_DPLL_NOT_REGISTERED(dpll);
316 		WARN_ON_ONCE(!xa_empty(&dpll->pin_refs));
317 		xa_destroy(&dpll->pin_refs);
318 		xa_erase(&dpll_device_xa, dpll->id);
319 		WARN_ON(!list_empty(&dpll->registration_list));
320 		kfree(dpll);
321 	}
322 	mutex_unlock(&dpll_lock);
323 }
324 EXPORT_SYMBOL_GPL(dpll_device_put);
325 
326 static struct dpll_device_registration *
327 dpll_device_registration_find(struct dpll_device *dpll,
328 			      const struct dpll_device_ops *ops, void *priv)
329 {
330 	struct dpll_device_registration *reg;
331 
332 	list_for_each_entry(reg, &dpll->registration_list, list) {
333 		if (reg->ops == ops && reg->priv == priv)
334 			return reg;
335 	}
336 	return NULL;
337 }
338 
339 /**
340  * dpll_device_register - register the dpll device in the subsystem
341  * @dpll: pointer to a dpll
342  * @type: type of a dpll
343  * @ops: ops for a dpll device
344  * @priv: pointer to private information of owner
345  *
346  * Make dpll device available for user space.
347  *
348  * Context: Acquires a lock (dpll_lock)
349  * Return:
350  * * 0 on success
351  * * negative - error value
352  */
353 int dpll_device_register(struct dpll_device *dpll, enum dpll_type type,
354 			 const struct dpll_device_ops *ops, void *priv)
355 {
356 	struct dpll_device_registration *reg;
357 	bool first_registration = false;
358 
359 	if (WARN_ON(!ops))
360 		return -EINVAL;
361 	if (WARN_ON(!ops->mode_get))
362 		return -EINVAL;
363 	if (WARN_ON(!ops->lock_status_get))
364 		return -EINVAL;
365 	if (WARN_ON(type < DPLL_TYPE_PPS || type > DPLL_TYPE_MAX))
366 		return -EINVAL;
367 
368 	mutex_lock(&dpll_lock);
369 	reg = dpll_device_registration_find(dpll, ops, priv);
370 	if (reg) {
371 		mutex_unlock(&dpll_lock);
372 		return -EEXIST;
373 	}
374 
375 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
376 	if (!reg) {
377 		mutex_unlock(&dpll_lock);
378 		return -ENOMEM;
379 	}
380 	reg->ops = ops;
381 	reg->priv = priv;
382 	dpll->type = type;
383 	first_registration = list_empty(&dpll->registration_list);
384 	list_add_tail(&reg->list, &dpll->registration_list);
385 	if (!first_registration) {
386 		mutex_unlock(&dpll_lock);
387 		return 0;
388 	}
389 
390 	xa_set_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
391 	dpll_device_create_ntf(dpll);
392 	mutex_unlock(&dpll_lock);
393 
394 	return 0;
395 }
396 EXPORT_SYMBOL_GPL(dpll_device_register);
397 
398 /**
399  * dpll_device_unregister - unregister dpll device
400  * @dpll: registered dpll pointer
401  * @ops: ops for a dpll device
402  * @priv: pointer to private information of owner
403  *
404  * Unregister device, make it unavailable for userspace.
405  * Note: It does not free the memory
406  * Context: Acquires a lock (dpll_lock)
407  */
408 void dpll_device_unregister(struct dpll_device *dpll,
409 			    const struct dpll_device_ops *ops, void *priv)
410 {
411 	struct dpll_device_registration *reg;
412 
413 	mutex_lock(&dpll_lock);
414 	ASSERT_DPLL_REGISTERED(dpll);
415 	dpll_device_delete_ntf(dpll);
416 	reg = dpll_device_registration_find(dpll, ops, priv);
417 	if (WARN_ON(!reg)) {
418 		mutex_unlock(&dpll_lock);
419 		return;
420 	}
421 	list_del(&reg->list);
422 	kfree(reg);
423 
424 	if (!list_empty(&dpll->registration_list)) {
425 		mutex_unlock(&dpll_lock);
426 		return;
427 	}
428 	xa_clear_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
429 	mutex_unlock(&dpll_lock);
430 }
431 EXPORT_SYMBOL_GPL(dpll_device_unregister);
432 
433 static void dpll_pin_prop_free(struct dpll_pin_properties *prop)
434 {
435 	kfree(prop->package_label);
436 	kfree(prop->panel_label);
437 	kfree(prop->board_label);
438 	kfree(prop->freq_supported);
439 }
440 
441 static int dpll_pin_prop_dup(const struct dpll_pin_properties *src,
442 			     struct dpll_pin_properties *dst)
443 {
444 	memcpy(dst, src, sizeof(*dst));
445 	if (src->freq_supported && src->freq_supported_num) {
446 		size_t freq_size = src->freq_supported_num *
447 				   sizeof(*src->freq_supported);
448 		dst->freq_supported = kmemdup(src->freq_supported,
449 					      freq_size, GFP_KERNEL);
450 		if (!src->freq_supported)
451 			return -ENOMEM;
452 	}
453 	if (src->board_label) {
454 		dst->board_label = kstrdup(src->board_label, GFP_KERNEL);
455 		if (!dst->board_label)
456 			goto err_board_label;
457 	}
458 	if (src->panel_label) {
459 		dst->panel_label = kstrdup(src->panel_label, GFP_KERNEL);
460 		if (!dst->panel_label)
461 			goto err_panel_label;
462 	}
463 	if (src->package_label) {
464 		dst->package_label = kstrdup(src->package_label, GFP_KERNEL);
465 		if (!dst->package_label)
466 			goto err_package_label;
467 	}
468 
469 	return 0;
470 
471 err_package_label:
472 	kfree(dst->panel_label);
473 err_panel_label:
474 	kfree(dst->board_label);
475 err_board_label:
476 	kfree(dst->freq_supported);
477 	return -ENOMEM;
478 }
479 
480 static struct dpll_pin *
481 dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
482 	       const struct dpll_pin_properties *prop)
483 {
484 	struct dpll_pin *pin;
485 	int ret;
486 
487 	pin = kzalloc(sizeof(*pin), GFP_KERNEL);
488 	if (!pin)
489 		return ERR_PTR(-ENOMEM);
490 	pin->pin_idx = pin_idx;
491 	pin->clock_id = clock_id;
492 	pin->module = module;
493 	if (WARN_ON(prop->type < DPLL_PIN_TYPE_MUX ||
494 		    prop->type > DPLL_PIN_TYPE_MAX)) {
495 		ret = -EINVAL;
496 		goto err_pin_prop;
497 	}
498 	ret = dpll_pin_prop_dup(prop, &pin->prop);
499 	if (ret)
500 		goto err_pin_prop;
501 	refcount_set(&pin->refcount, 1);
502 	xa_init_flags(&pin->dpll_refs, XA_FLAGS_ALLOC);
503 	xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
504 	ret = xa_alloc_cyclic(&dpll_pin_xa, &pin->id, pin, xa_limit_32b,
505 			      &dpll_pin_xa_id, GFP_KERNEL);
506 	if (ret)
507 		goto err_xa_alloc;
508 	return pin;
509 err_xa_alloc:
510 	xa_destroy(&pin->dpll_refs);
511 	xa_destroy(&pin->parent_refs);
512 	dpll_pin_prop_free(&pin->prop);
513 err_pin_prop:
514 	kfree(pin);
515 	return ERR_PTR(ret);
516 }
517 
518 /**
519  * dpll_pin_get - find existing or create new dpll pin
520  * @clock_id: clock_id of creator
521  * @pin_idx: idx given by dev driver
522  * @module: reference to registering module
523  * @prop: dpll pin properties
524  *
525  * Get existing object of a pin (unique for given arguments) or create new
526  * if doesn't exist yet.
527  *
528  * Context: Acquires a lock (dpll_lock)
529  * Return:
530  * * valid allocated dpll_pin struct pointer if succeeded
531  * * ERR_PTR(X) - error
532  */
533 struct dpll_pin *
534 dpll_pin_get(u64 clock_id, u32 pin_idx, struct module *module,
535 	     const struct dpll_pin_properties *prop)
536 {
537 	struct dpll_pin *pos, *ret = NULL;
538 	unsigned long i;
539 
540 	mutex_lock(&dpll_lock);
541 	xa_for_each(&dpll_pin_xa, i, pos) {
542 		if (pos->clock_id == clock_id &&
543 		    pos->pin_idx == pin_idx &&
544 		    pos->module == module) {
545 			ret = pos;
546 			refcount_inc(&ret->refcount);
547 			break;
548 		}
549 	}
550 	if (!ret)
551 		ret = dpll_pin_alloc(clock_id, pin_idx, module, prop);
552 	mutex_unlock(&dpll_lock);
553 
554 	return ret;
555 }
556 EXPORT_SYMBOL_GPL(dpll_pin_get);
557 
558 /**
559  * dpll_pin_put - decrease the refcount and free memory if possible
560  * @pin: pointer to a pin to be put
561  *
562  * Drop reference for a pin, if all references are gone, delete pin object.
563  *
564  * Context: Acquires a lock (dpll_lock)
565  */
566 void dpll_pin_put(struct dpll_pin *pin)
567 {
568 	mutex_lock(&dpll_lock);
569 	if (refcount_dec_and_test(&pin->refcount)) {
570 		xa_erase(&dpll_pin_xa, pin->id);
571 		xa_destroy(&pin->dpll_refs);
572 		xa_destroy(&pin->parent_refs);
573 		dpll_pin_prop_free(&pin->prop);
574 		kfree_rcu(pin, rcu);
575 	}
576 	mutex_unlock(&dpll_lock);
577 }
578 EXPORT_SYMBOL_GPL(dpll_pin_put);
579 
580 static int
581 __dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
582 		    const struct dpll_pin_ops *ops, void *priv)
583 {
584 	int ret;
585 
586 	ret = dpll_xa_ref_pin_add(&dpll->pin_refs, pin, ops, priv);
587 	if (ret)
588 		return ret;
589 	ret = dpll_xa_ref_dpll_add(&pin->dpll_refs, dpll, ops, priv);
590 	if (ret)
591 		goto ref_pin_del;
592 	xa_set_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
593 	dpll_pin_create_ntf(pin);
594 
595 	return ret;
596 
597 ref_pin_del:
598 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
599 	return ret;
600 }
601 
602 /**
603  * dpll_pin_register - register the dpll pin in the subsystem
604  * @dpll: pointer to a dpll
605  * @pin: pointer to a dpll pin
606  * @ops: ops for a dpll pin ops
607  * @priv: pointer to private information of owner
608  *
609  * Context: Acquires a lock (dpll_lock)
610  * Return:
611  * * 0 on success
612  * * negative - error value
613  */
614 int
615 dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
616 		  const struct dpll_pin_ops *ops, void *priv)
617 {
618 	int ret;
619 
620 	if (WARN_ON(!ops) ||
621 	    WARN_ON(!ops->state_on_dpll_get) ||
622 	    WARN_ON(!ops->direction_get))
623 		return -EINVAL;
624 
625 	mutex_lock(&dpll_lock);
626 	if (WARN_ON(!(dpll->module == pin->module &&
627 		      dpll->clock_id == pin->clock_id)))
628 		ret = -EINVAL;
629 	else
630 		ret = __dpll_pin_register(dpll, pin, ops, priv);
631 	mutex_unlock(&dpll_lock);
632 
633 	return ret;
634 }
635 EXPORT_SYMBOL_GPL(dpll_pin_register);
636 
637 static void
638 __dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
639 		      const struct dpll_pin_ops *ops, void *priv)
640 {
641 	ASSERT_DPLL_PIN_REGISTERED(pin);
642 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
643 	dpll_xa_ref_dpll_del(&pin->dpll_refs, dpll, ops, priv);
644 	if (xa_empty(&pin->dpll_refs))
645 		xa_clear_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
646 }
647 
648 /**
649  * dpll_pin_unregister - unregister dpll pin from dpll device
650  * @dpll: registered dpll pointer
651  * @pin: pointer to a pin
652  * @ops: ops for a dpll pin
653  * @priv: pointer to private information of owner
654  *
655  * Note: It does not free the memory
656  * Context: Acquires a lock (dpll_lock)
657  */
658 void dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
659 			 const struct dpll_pin_ops *ops, void *priv)
660 {
661 	if (WARN_ON(xa_empty(&dpll->pin_refs)))
662 		return;
663 	if (WARN_ON(!xa_empty(&pin->parent_refs)))
664 		return;
665 
666 	mutex_lock(&dpll_lock);
667 	dpll_pin_delete_ntf(pin);
668 	__dpll_pin_unregister(dpll, pin, ops, priv);
669 	mutex_unlock(&dpll_lock);
670 }
671 EXPORT_SYMBOL_GPL(dpll_pin_unregister);
672 
673 /**
674  * dpll_pin_on_pin_register - register a pin with a parent pin
675  * @parent: pointer to a parent pin
676  * @pin: pointer to a pin
677  * @ops: ops for a dpll pin
678  * @priv: pointer to private information of owner
679  *
680  * Register a pin with a parent pin, create references between them and
681  * between newly registered pin and dplls connected with a parent pin.
682  *
683  * Context: Acquires a lock (dpll_lock)
684  * Return:
685  * * 0 on success
686  * * negative - error value
687  */
688 int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
689 			     const struct dpll_pin_ops *ops, void *priv)
690 {
691 	struct dpll_pin_ref *ref;
692 	unsigned long i, stop;
693 	int ret;
694 
695 	if (WARN_ON(parent->prop.type != DPLL_PIN_TYPE_MUX))
696 		return -EINVAL;
697 
698 	if (WARN_ON(!ops) ||
699 	    WARN_ON(!ops->state_on_pin_get) ||
700 	    WARN_ON(!ops->direction_get))
701 		return -EINVAL;
702 
703 	mutex_lock(&dpll_lock);
704 	ret = dpll_xa_ref_pin_add(&pin->parent_refs, parent, ops, priv);
705 	if (ret)
706 		goto unlock;
707 	refcount_inc(&pin->refcount);
708 	xa_for_each(&parent->dpll_refs, i, ref) {
709 		ret = __dpll_pin_register(ref->dpll, pin, ops, priv);
710 		if (ret) {
711 			stop = i;
712 			goto dpll_unregister;
713 		}
714 		dpll_pin_create_ntf(pin);
715 	}
716 	mutex_unlock(&dpll_lock);
717 
718 	return ret;
719 
720 dpll_unregister:
721 	xa_for_each(&parent->dpll_refs, i, ref)
722 		if (i < stop) {
723 			__dpll_pin_unregister(ref->dpll, pin, ops, priv);
724 			dpll_pin_delete_ntf(pin);
725 		}
726 	refcount_dec(&pin->refcount);
727 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
728 unlock:
729 	mutex_unlock(&dpll_lock);
730 	return ret;
731 }
732 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_register);
733 
734 /**
735  * dpll_pin_on_pin_unregister - unregister dpll pin from a parent pin
736  * @parent: pointer to a parent pin
737  * @pin: pointer to a pin
738  * @ops: ops for a dpll pin
739  * @priv: pointer to private information of owner
740  *
741  * Context: Acquires a lock (dpll_lock)
742  * Note: It does not free the memory
743  */
744 void dpll_pin_on_pin_unregister(struct dpll_pin *parent, struct dpll_pin *pin,
745 				const struct dpll_pin_ops *ops, void *priv)
746 {
747 	struct dpll_pin_ref *ref;
748 	unsigned long i;
749 
750 	mutex_lock(&dpll_lock);
751 	dpll_pin_delete_ntf(pin);
752 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
753 	refcount_dec(&pin->refcount);
754 	xa_for_each(&pin->dpll_refs, i, ref)
755 		__dpll_pin_unregister(ref->dpll, pin, ops, priv);
756 	mutex_unlock(&dpll_lock);
757 }
758 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_unregister);
759 
760 static struct dpll_device_registration *
761 dpll_device_registration_first(struct dpll_device *dpll)
762 {
763 	struct dpll_device_registration *reg;
764 
765 	reg = list_first_entry_or_null((struct list_head *)&dpll->registration_list,
766 				       struct dpll_device_registration, list);
767 	WARN_ON(!reg);
768 	return reg;
769 }
770 
771 void *dpll_priv(struct dpll_device *dpll)
772 {
773 	struct dpll_device_registration *reg;
774 
775 	reg = dpll_device_registration_first(dpll);
776 	return reg->priv;
777 }
778 
779 const struct dpll_device_ops *dpll_device_ops(struct dpll_device *dpll)
780 {
781 	struct dpll_device_registration *reg;
782 
783 	reg = dpll_device_registration_first(dpll);
784 	return reg->ops;
785 }
786 
787 static struct dpll_pin_registration *
788 dpll_pin_registration_first(struct dpll_pin_ref *ref)
789 {
790 	struct dpll_pin_registration *reg;
791 
792 	reg = list_first_entry_or_null(&ref->registration_list,
793 				       struct dpll_pin_registration, list);
794 	WARN_ON(!reg);
795 	return reg;
796 }
797 
798 void *dpll_pin_on_dpll_priv(struct dpll_device *dpll,
799 			    struct dpll_pin *pin)
800 {
801 	struct dpll_pin_registration *reg;
802 	struct dpll_pin_ref *ref;
803 
804 	ref = xa_load(&dpll->pin_refs, pin->pin_idx);
805 	if (!ref)
806 		return NULL;
807 	reg = dpll_pin_registration_first(ref);
808 	return reg->priv;
809 }
810 
811 void *dpll_pin_on_pin_priv(struct dpll_pin *parent,
812 			   struct dpll_pin *pin)
813 {
814 	struct dpll_pin_registration *reg;
815 	struct dpll_pin_ref *ref;
816 
817 	ref = xa_load(&pin->parent_refs, parent->pin_idx);
818 	if (!ref)
819 		return NULL;
820 	reg = dpll_pin_registration_first(ref);
821 	return reg->priv;
822 }
823 
824 const struct dpll_pin_ops *dpll_pin_ops(struct dpll_pin_ref *ref)
825 {
826 	struct dpll_pin_registration *reg;
827 
828 	reg = dpll_pin_registration_first(ref);
829 	return reg->ops;
830 }
831 
832 static int __init dpll_init(void)
833 {
834 	int ret;
835 
836 	ret = genl_register_family(&dpll_nl_family);
837 	if (ret)
838 		goto error;
839 
840 	return 0;
841 
842 error:
843 	mutex_destroy(&dpll_lock);
844 	return ret;
845 }
846 
847 static void __exit dpll_exit(void)
848 {
849 	genl_unregister_family(&dpll_nl_family);
850 	mutex_destroy(&dpll_lock);
851 }
852 
853 subsys_initcall(dpll_init);
854 module_exit(dpll_exit);
855