xref: /linux/drivers/dpll/dpll_core.c (revision 2b0cfa6e49566c8fa6759734cf821aa6e8271a9e)
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_device *dpll_device_get_by_id(int id)
48 {
49 	if (xa_get_mark(&dpll_device_xa, id, DPLL_REGISTERED))
50 		return xa_load(&dpll_device_xa, id);
51 
52 	return NULL;
53 }
54 
55 static struct dpll_pin_registration *
56 dpll_pin_registration_find(struct dpll_pin_ref *ref,
57 			   const struct dpll_pin_ops *ops, void *priv)
58 {
59 	struct dpll_pin_registration *reg;
60 
61 	list_for_each_entry(reg, &ref->registration_list, list) {
62 		if (reg->ops == ops && reg->priv == priv)
63 			return reg;
64 	}
65 	return NULL;
66 }
67 
68 static int
69 dpll_xa_ref_pin_add(struct xarray *xa_pins, struct dpll_pin *pin,
70 		    const struct dpll_pin_ops *ops, void *priv)
71 {
72 	struct dpll_pin_registration *reg;
73 	struct dpll_pin_ref *ref;
74 	bool ref_exists = false;
75 	unsigned long i;
76 	int ret;
77 
78 	xa_for_each(xa_pins, i, ref) {
79 		if (ref->pin != pin)
80 			continue;
81 		reg = dpll_pin_registration_find(ref, ops, priv);
82 		if (reg) {
83 			refcount_inc(&ref->refcount);
84 			return 0;
85 		}
86 		ref_exists = true;
87 		break;
88 	}
89 
90 	if (!ref_exists) {
91 		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
92 		if (!ref)
93 			return -ENOMEM;
94 		ref->pin = pin;
95 		INIT_LIST_HEAD(&ref->registration_list);
96 		ret = xa_insert(xa_pins, pin->pin_idx, ref, GFP_KERNEL);
97 		if (ret) {
98 			kfree(ref);
99 			return ret;
100 		}
101 		refcount_set(&ref->refcount, 1);
102 	}
103 
104 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
105 	if (!reg) {
106 		if (!ref_exists) {
107 			xa_erase(xa_pins, pin->pin_idx);
108 			kfree(ref);
109 		}
110 		return -ENOMEM;
111 	}
112 	reg->ops = ops;
113 	reg->priv = priv;
114 	if (ref_exists)
115 		refcount_inc(&ref->refcount);
116 	list_add_tail(&reg->list, &ref->registration_list);
117 
118 	return 0;
119 }
120 
121 static int dpll_xa_ref_pin_del(struct xarray *xa_pins, struct dpll_pin *pin,
122 			       const struct dpll_pin_ops *ops, void *priv)
123 {
124 	struct dpll_pin_registration *reg;
125 	struct dpll_pin_ref *ref;
126 	unsigned long i;
127 
128 	xa_for_each(xa_pins, i, ref) {
129 		if (ref->pin != pin)
130 			continue;
131 		reg = dpll_pin_registration_find(ref, ops, priv);
132 		if (WARN_ON(!reg))
133 			return -EINVAL;
134 		if (refcount_dec_and_test(&ref->refcount)) {
135 			list_del(&reg->list);
136 			kfree(reg);
137 			xa_erase(xa_pins, i);
138 			WARN_ON(!list_empty(&ref->registration_list));
139 			kfree(ref);
140 		}
141 		return 0;
142 	}
143 
144 	return -EINVAL;
145 }
146 
147 static int
148 dpll_xa_ref_dpll_add(struct xarray *xa_dplls, struct dpll_device *dpll,
149 		     const struct dpll_pin_ops *ops, void *priv)
150 {
151 	struct dpll_pin_registration *reg;
152 	struct dpll_pin_ref *ref;
153 	bool ref_exists = false;
154 	unsigned long i;
155 	int ret;
156 
157 	xa_for_each(xa_dplls, i, ref) {
158 		if (ref->dpll != dpll)
159 			continue;
160 		reg = dpll_pin_registration_find(ref, ops, priv);
161 		if (reg) {
162 			refcount_inc(&ref->refcount);
163 			return 0;
164 		}
165 		ref_exists = true;
166 		break;
167 	}
168 
169 	if (!ref_exists) {
170 		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
171 		if (!ref)
172 			return -ENOMEM;
173 		ref->dpll = dpll;
174 		INIT_LIST_HEAD(&ref->registration_list);
175 		ret = xa_insert(xa_dplls, dpll->id, ref, GFP_KERNEL);
176 		if (ret) {
177 			kfree(ref);
178 			return ret;
179 		}
180 		refcount_set(&ref->refcount, 1);
181 	}
182 
183 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
184 	if (!reg) {
185 		if (!ref_exists) {
186 			xa_erase(xa_dplls, dpll->id);
187 			kfree(ref);
188 		}
189 		return -ENOMEM;
190 	}
191 	reg->ops = ops;
192 	reg->priv = priv;
193 	if (ref_exists)
194 		refcount_inc(&ref->refcount);
195 	list_add_tail(&reg->list, &ref->registration_list);
196 
197 	return 0;
198 }
199 
200 static void
201 dpll_xa_ref_dpll_del(struct xarray *xa_dplls, struct dpll_device *dpll,
202 		     const struct dpll_pin_ops *ops, void *priv)
203 {
204 	struct dpll_pin_registration *reg;
205 	struct dpll_pin_ref *ref;
206 	unsigned long i;
207 
208 	xa_for_each(xa_dplls, i, ref) {
209 		if (ref->dpll != dpll)
210 			continue;
211 		reg = dpll_pin_registration_find(ref, ops, priv);
212 		if (WARN_ON(!reg))
213 			return;
214 		if (refcount_dec_and_test(&ref->refcount)) {
215 			list_del(&reg->list);
216 			kfree(reg);
217 			xa_erase(xa_dplls, i);
218 			WARN_ON(!list_empty(&ref->registration_list));
219 			kfree(ref);
220 		}
221 		return;
222 	}
223 }
224 
225 struct dpll_pin_ref *dpll_xa_ref_dpll_first(struct xarray *xa_refs)
226 {
227 	struct dpll_pin_ref *ref;
228 	unsigned long i = 0;
229 
230 	ref = xa_find(xa_refs, &i, ULONG_MAX, XA_PRESENT);
231 	WARN_ON(!ref);
232 	return ref;
233 }
234 
235 static struct dpll_device *
236 dpll_device_alloc(const u64 clock_id, u32 device_idx, struct module *module)
237 {
238 	struct dpll_device *dpll;
239 	int ret;
240 
241 	dpll = kzalloc(sizeof(*dpll), GFP_KERNEL);
242 	if (!dpll)
243 		return ERR_PTR(-ENOMEM);
244 	refcount_set(&dpll->refcount, 1);
245 	INIT_LIST_HEAD(&dpll->registration_list);
246 	dpll->device_idx = device_idx;
247 	dpll->clock_id = clock_id;
248 	dpll->module = module;
249 	ret = xa_alloc_cyclic(&dpll_device_xa, &dpll->id, dpll, xa_limit_32b,
250 			      &dpll_device_xa_id, GFP_KERNEL);
251 	if (ret < 0) {
252 		kfree(dpll);
253 		return ERR_PTR(ret);
254 	}
255 	xa_init_flags(&dpll->pin_refs, XA_FLAGS_ALLOC);
256 
257 	return dpll;
258 }
259 
260 /**
261  * dpll_device_get - find existing or create new dpll device
262  * @clock_id: clock_id of creator
263  * @device_idx: idx given by device driver
264  * @module: reference to registering module
265  *
266  * Get existing object of a dpll device, unique for given arguments.
267  * Create new if doesn't exist yet.
268  *
269  * Context: Acquires a lock (dpll_lock)
270  * Return:
271  * * valid dpll_device struct pointer if succeeded
272  * * ERR_PTR(X) - error
273  */
274 struct dpll_device *
275 dpll_device_get(u64 clock_id, u32 device_idx, struct module *module)
276 {
277 	struct dpll_device *dpll, *ret = NULL;
278 	unsigned long index;
279 
280 	mutex_lock(&dpll_lock);
281 	xa_for_each(&dpll_device_xa, index, dpll) {
282 		if (dpll->clock_id == clock_id &&
283 		    dpll->device_idx == device_idx &&
284 		    dpll->module == module) {
285 			ret = dpll;
286 			refcount_inc(&ret->refcount);
287 			break;
288 		}
289 	}
290 	if (!ret)
291 		ret = dpll_device_alloc(clock_id, device_idx, module);
292 	mutex_unlock(&dpll_lock);
293 
294 	return ret;
295 }
296 EXPORT_SYMBOL_GPL(dpll_device_get);
297 
298 /**
299  * dpll_device_put - decrease the refcount and free memory if possible
300  * @dpll: dpll_device struct pointer
301  *
302  * Context: Acquires a lock (dpll_lock)
303  * Drop reference for a dpll device, if all references are gone, delete
304  * dpll device object.
305  */
306 void dpll_device_put(struct dpll_device *dpll)
307 {
308 	mutex_lock(&dpll_lock);
309 	if (refcount_dec_and_test(&dpll->refcount)) {
310 		ASSERT_DPLL_NOT_REGISTERED(dpll);
311 		WARN_ON_ONCE(!xa_empty(&dpll->pin_refs));
312 		xa_destroy(&dpll->pin_refs);
313 		xa_erase(&dpll_device_xa, dpll->id);
314 		WARN_ON(!list_empty(&dpll->registration_list));
315 		kfree(dpll);
316 	}
317 	mutex_unlock(&dpll_lock);
318 }
319 EXPORT_SYMBOL_GPL(dpll_device_put);
320 
321 static struct dpll_device_registration *
322 dpll_device_registration_find(struct dpll_device *dpll,
323 			      const struct dpll_device_ops *ops, void *priv)
324 {
325 	struct dpll_device_registration *reg;
326 
327 	list_for_each_entry(reg, &dpll->registration_list, list) {
328 		if (reg->ops == ops && reg->priv == priv)
329 			return reg;
330 	}
331 	return NULL;
332 }
333 
334 /**
335  * dpll_device_register - register the dpll device in the subsystem
336  * @dpll: pointer to a dpll
337  * @type: type of a dpll
338  * @ops: ops for a dpll device
339  * @priv: pointer to private information of owner
340  *
341  * Make dpll device available for user space.
342  *
343  * Context: Acquires a lock (dpll_lock)
344  * Return:
345  * * 0 on success
346  * * negative - error value
347  */
348 int dpll_device_register(struct dpll_device *dpll, enum dpll_type type,
349 			 const struct dpll_device_ops *ops, void *priv)
350 {
351 	struct dpll_device_registration *reg;
352 	bool first_registration = false;
353 
354 	if (WARN_ON(!ops))
355 		return -EINVAL;
356 	if (WARN_ON(!ops->mode_get))
357 		return -EINVAL;
358 	if (WARN_ON(!ops->lock_status_get))
359 		return -EINVAL;
360 	if (WARN_ON(type < DPLL_TYPE_PPS || type > DPLL_TYPE_MAX))
361 		return -EINVAL;
362 
363 	mutex_lock(&dpll_lock);
364 	reg = dpll_device_registration_find(dpll, ops, priv);
365 	if (reg) {
366 		mutex_unlock(&dpll_lock);
367 		return -EEXIST;
368 	}
369 
370 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
371 	if (!reg) {
372 		mutex_unlock(&dpll_lock);
373 		return -ENOMEM;
374 	}
375 	reg->ops = ops;
376 	reg->priv = priv;
377 	dpll->type = type;
378 	first_registration = list_empty(&dpll->registration_list);
379 	list_add_tail(&reg->list, &dpll->registration_list);
380 	if (!first_registration) {
381 		mutex_unlock(&dpll_lock);
382 		return 0;
383 	}
384 
385 	xa_set_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
386 	dpll_device_create_ntf(dpll);
387 	mutex_unlock(&dpll_lock);
388 
389 	return 0;
390 }
391 EXPORT_SYMBOL_GPL(dpll_device_register);
392 
393 /**
394  * dpll_device_unregister - unregister dpll device
395  * @dpll: registered dpll pointer
396  * @ops: ops for a dpll device
397  * @priv: pointer to private information of owner
398  *
399  * Unregister device, make it unavailable for userspace.
400  * Note: It does not free the memory
401  * Context: Acquires a lock (dpll_lock)
402  */
403 void dpll_device_unregister(struct dpll_device *dpll,
404 			    const struct dpll_device_ops *ops, void *priv)
405 {
406 	struct dpll_device_registration *reg;
407 
408 	mutex_lock(&dpll_lock);
409 	ASSERT_DPLL_REGISTERED(dpll);
410 	dpll_device_delete_ntf(dpll);
411 	reg = dpll_device_registration_find(dpll, ops, priv);
412 	if (WARN_ON(!reg)) {
413 		mutex_unlock(&dpll_lock);
414 		return;
415 	}
416 	list_del(&reg->list);
417 	kfree(reg);
418 
419 	if (!list_empty(&dpll->registration_list)) {
420 		mutex_unlock(&dpll_lock);
421 		return;
422 	}
423 	xa_clear_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
424 	mutex_unlock(&dpll_lock);
425 }
426 EXPORT_SYMBOL_GPL(dpll_device_unregister);
427 
428 static void dpll_pin_prop_free(struct dpll_pin_properties *prop)
429 {
430 	kfree(prop->package_label);
431 	kfree(prop->panel_label);
432 	kfree(prop->board_label);
433 	kfree(prop->freq_supported);
434 }
435 
436 static int dpll_pin_prop_dup(const struct dpll_pin_properties *src,
437 			     struct dpll_pin_properties *dst)
438 {
439 	memcpy(dst, src, sizeof(*dst));
440 	if (src->freq_supported && src->freq_supported_num) {
441 		size_t freq_size = src->freq_supported_num *
442 				   sizeof(*src->freq_supported);
443 		dst->freq_supported = kmemdup(src->freq_supported,
444 					      freq_size, GFP_KERNEL);
445 		if (!src->freq_supported)
446 			return -ENOMEM;
447 	}
448 	if (src->board_label) {
449 		dst->board_label = kstrdup(src->board_label, GFP_KERNEL);
450 		if (!dst->board_label)
451 			goto err_board_label;
452 	}
453 	if (src->panel_label) {
454 		dst->panel_label = kstrdup(src->panel_label, GFP_KERNEL);
455 		if (!dst->panel_label)
456 			goto err_panel_label;
457 	}
458 	if (src->package_label) {
459 		dst->package_label = kstrdup(src->package_label, GFP_KERNEL);
460 		if (!dst->package_label)
461 			goto err_package_label;
462 	}
463 
464 	return 0;
465 
466 err_package_label:
467 	kfree(dst->panel_label);
468 err_panel_label:
469 	kfree(dst->board_label);
470 err_board_label:
471 	kfree(dst->freq_supported);
472 	return -ENOMEM;
473 }
474 
475 static struct dpll_pin *
476 dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
477 	       const struct dpll_pin_properties *prop)
478 {
479 	struct dpll_pin *pin;
480 	int ret;
481 
482 	pin = kzalloc(sizeof(*pin), GFP_KERNEL);
483 	if (!pin)
484 		return ERR_PTR(-ENOMEM);
485 	pin->pin_idx = pin_idx;
486 	pin->clock_id = clock_id;
487 	pin->module = module;
488 	if (WARN_ON(prop->type < DPLL_PIN_TYPE_MUX ||
489 		    prop->type > DPLL_PIN_TYPE_MAX)) {
490 		ret = -EINVAL;
491 		goto err_pin_prop;
492 	}
493 	ret = dpll_pin_prop_dup(prop, &pin->prop);
494 	if (ret)
495 		goto err_pin_prop;
496 	refcount_set(&pin->refcount, 1);
497 	xa_init_flags(&pin->dpll_refs, XA_FLAGS_ALLOC);
498 	xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
499 	ret = xa_alloc_cyclic(&dpll_pin_xa, &pin->id, pin, xa_limit_32b,
500 			      &dpll_pin_xa_id, GFP_KERNEL);
501 	if (ret)
502 		goto err_xa_alloc;
503 	return pin;
504 err_xa_alloc:
505 	xa_destroy(&pin->dpll_refs);
506 	xa_destroy(&pin->parent_refs);
507 	dpll_pin_prop_free(&pin->prop);
508 err_pin_prop:
509 	kfree(pin);
510 	return ERR_PTR(ret);
511 }
512 
513 /**
514  * dpll_pin_get - find existing or create new dpll pin
515  * @clock_id: clock_id of creator
516  * @pin_idx: idx given by dev driver
517  * @module: reference to registering module
518  * @prop: dpll pin properties
519  *
520  * Get existing object of a pin (unique for given arguments) or create new
521  * if doesn't exist yet.
522  *
523  * Context: Acquires a lock (dpll_lock)
524  * Return:
525  * * valid allocated dpll_pin struct pointer if succeeded
526  * * ERR_PTR(X) - error
527  */
528 struct dpll_pin *
529 dpll_pin_get(u64 clock_id, u32 pin_idx, struct module *module,
530 	     const struct dpll_pin_properties *prop)
531 {
532 	struct dpll_pin *pos, *ret = NULL;
533 	unsigned long i;
534 
535 	mutex_lock(&dpll_lock);
536 	xa_for_each(&dpll_pin_xa, i, pos) {
537 		if (pos->clock_id == clock_id &&
538 		    pos->pin_idx == pin_idx &&
539 		    pos->module == module) {
540 			ret = pos;
541 			refcount_inc(&ret->refcount);
542 			break;
543 		}
544 	}
545 	if (!ret)
546 		ret = dpll_pin_alloc(clock_id, pin_idx, module, prop);
547 	mutex_unlock(&dpll_lock);
548 
549 	return ret;
550 }
551 EXPORT_SYMBOL_GPL(dpll_pin_get);
552 
553 /**
554  * dpll_pin_put - decrease the refcount and free memory if possible
555  * @pin: pointer to a pin to be put
556  *
557  * Drop reference for a pin, if all references are gone, delete pin object.
558  *
559  * Context: Acquires a lock (dpll_lock)
560  */
561 void dpll_pin_put(struct dpll_pin *pin)
562 {
563 	mutex_lock(&dpll_lock);
564 	if (refcount_dec_and_test(&pin->refcount)) {
565 		xa_erase(&dpll_pin_xa, pin->id);
566 		xa_destroy(&pin->dpll_refs);
567 		xa_destroy(&pin->parent_refs);
568 		dpll_pin_prop_free(&pin->prop);
569 		kfree(pin);
570 	}
571 	mutex_unlock(&dpll_lock);
572 }
573 EXPORT_SYMBOL_GPL(dpll_pin_put);
574 
575 static int
576 __dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
577 		    const struct dpll_pin_ops *ops, void *priv)
578 {
579 	int ret;
580 
581 	ret = dpll_xa_ref_pin_add(&dpll->pin_refs, pin, ops, priv);
582 	if (ret)
583 		return ret;
584 	ret = dpll_xa_ref_dpll_add(&pin->dpll_refs, dpll, ops, priv);
585 	if (ret)
586 		goto ref_pin_del;
587 	xa_set_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
588 	dpll_pin_create_ntf(pin);
589 
590 	return ret;
591 
592 ref_pin_del:
593 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
594 	return ret;
595 }
596 
597 /**
598  * dpll_pin_register - register the dpll pin in the subsystem
599  * @dpll: pointer to a dpll
600  * @pin: pointer to a dpll pin
601  * @ops: ops for a dpll pin ops
602  * @priv: pointer to private information of owner
603  *
604  * Context: Acquires a lock (dpll_lock)
605  * Return:
606  * * 0 on success
607  * * negative - error value
608  */
609 int
610 dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
611 		  const struct dpll_pin_ops *ops, void *priv)
612 {
613 	int ret;
614 
615 	if (WARN_ON(!ops) ||
616 	    WARN_ON(!ops->state_on_dpll_get) ||
617 	    WARN_ON(!ops->direction_get))
618 		return -EINVAL;
619 
620 	mutex_lock(&dpll_lock);
621 	if (WARN_ON(!(dpll->module == pin->module &&
622 		      dpll->clock_id == pin->clock_id)))
623 		ret = -EINVAL;
624 	else
625 		ret = __dpll_pin_register(dpll, pin, ops, priv);
626 	mutex_unlock(&dpll_lock);
627 
628 	return ret;
629 }
630 EXPORT_SYMBOL_GPL(dpll_pin_register);
631 
632 static void
633 __dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
634 		      const struct dpll_pin_ops *ops, void *priv)
635 {
636 	ASSERT_DPLL_PIN_REGISTERED(pin);
637 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
638 	dpll_xa_ref_dpll_del(&pin->dpll_refs, dpll, ops, priv);
639 	if (xa_empty(&pin->dpll_refs))
640 		xa_clear_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
641 }
642 
643 /**
644  * dpll_pin_unregister - unregister dpll pin from dpll device
645  * @dpll: registered dpll pointer
646  * @pin: pointer to a pin
647  * @ops: ops for a dpll pin
648  * @priv: pointer to private information of owner
649  *
650  * Note: It does not free the memory
651  * Context: Acquires a lock (dpll_lock)
652  */
653 void dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
654 			 const struct dpll_pin_ops *ops, void *priv)
655 {
656 	if (WARN_ON(xa_empty(&dpll->pin_refs)))
657 		return;
658 	if (WARN_ON(!xa_empty(&pin->parent_refs)))
659 		return;
660 
661 	mutex_lock(&dpll_lock);
662 	dpll_pin_delete_ntf(pin);
663 	__dpll_pin_unregister(dpll, pin, ops, priv);
664 	mutex_unlock(&dpll_lock);
665 }
666 EXPORT_SYMBOL_GPL(dpll_pin_unregister);
667 
668 /**
669  * dpll_pin_on_pin_register - register a pin with a parent pin
670  * @parent: pointer to a parent pin
671  * @pin: pointer to a pin
672  * @ops: ops for a dpll pin
673  * @priv: pointer to private information of owner
674  *
675  * Register a pin with a parent pin, create references between them and
676  * between newly registered pin and dplls connected with a parent pin.
677  *
678  * Context: Acquires a lock (dpll_lock)
679  * Return:
680  * * 0 on success
681  * * negative - error value
682  */
683 int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
684 			     const struct dpll_pin_ops *ops, void *priv)
685 {
686 	struct dpll_pin_ref *ref;
687 	unsigned long i, stop;
688 	int ret;
689 
690 	if (WARN_ON(parent->prop.type != DPLL_PIN_TYPE_MUX))
691 		return -EINVAL;
692 
693 	if (WARN_ON(!ops) ||
694 	    WARN_ON(!ops->state_on_pin_get) ||
695 	    WARN_ON(!ops->direction_get))
696 		return -EINVAL;
697 
698 	mutex_lock(&dpll_lock);
699 	ret = dpll_xa_ref_pin_add(&pin->parent_refs, parent, ops, priv);
700 	if (ret)
701 		goto unlock;
702 	refcount_inc(&pin->refcount);
703 	xa_for_each(&parent->dpll_refs, i, ref) {
704 		ret = __dpll_pin_register(ref->dpll, pin, ops, priv);
705 		if (ret) {
706 			stop = i;
707 			goto dpll_unregister;
708 		}
709 		dpll_pin_create_ntf(pin);
710 	}
711 	mutex_unlock(&dpll_lock);
712 
713 	return ret;
714 
715 dpll_unregister:
716 	xa_for_each(&parent->dpll_refs, i, ref)
717 		if (i < stop) {
718 			__dpll_pin_unregister(ref->dpll, pin, ops, priv);
719 			dpll_pin_delete_ntf(pin);
720 		}
721 	refcount_dec(&pin->refcount);
722 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
723 unlock:
724 	mutex_unlock(&dpll_lock);
725 	return ret;
726 }
727 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_register);
728 
729 /**
730  * dpll_pin_on_pin_unregister - unregister dpll pin from a parent pin
731  * @parent: pointer to a parent pin
732  * @pin: pointer to a pin
733  * @ops: ops for a dpll pin
734  * @priv: pointer to private information of owner
735  *
736  * Context: Acquires a lock (dpll_lock)
737  * Note: It does not free the memory
738  */
739 void dpll_pin_on_pin_unregister(struct dpll_pin *parent, struct dpll_pin *pin,
740 				const struct dpll_pin_ops *ops, void *priv)
741 {
742 	struct dpll_pin_ref *ref;
743 	unsigned long i;
744 
745 	mutex_lock(&dpll_lock);
746 	dpll_pin_delete_ntf(pin);
747 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
748 	refcount_dec(&pin->refcount);
749 	xa_for_each(&pin->dpll_refs, i, ref)
750 		__dpll_pin_unregister(ref->dpll, pin, ops, priv);
751 	mutex_unlock(&dpll_lock);
752 }
753 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_unregister);
754 
755 static struct dpll_device_registration *
756 dpll_device_registration_first(struct dpll_device *dpll)
757 {
758 	struct dpll_device_registration *reg;
759 
760 	reg = list_first_entry_or_null((struct list_head *)&dpll->registration_list,
761 				       struct dpll_device_registration, list);
762 	WARN_ON(!reg);
763 	return reg;
764 }
765 
766 void *dpll_priv(struct dpll_device *dpll)
767 {
768 	struct dpll_device_registration *reg;
769 
770 	reg = dpll_device_registration_first(dpll);
771 	return reg->priv;
772 }
773 
774 const struct dpll_device_ops *dpll_device_ops(struct dpll_device *dpll)
775 {
776 	struct dpll_device_registration *reg;
777 
778 	reg = dpll_device_registration_first(dpll);
779 	return reg->ops;
780 }
781 
782 static struct dpll_pin_registration *
783 dpll_pin_registration_first(struct dpll_pin_ref *ref)
784 {
785 	struct dpll_pin_registration *reg;
786 
787 	reg = list_first_entry_or_null(&ref->registration_list,
788 				       struct dpll_pin_registration, list);
789 	WARN_ON(!reg);
790 	return reg;
791 }
792 
793 void *dpll_pin_on_dpll_priv(struct dpll_device *dpll,
794 			    struct dpll_pin *pin)
795 {
796 	struct dpll_pin_registration *reg;
797 	struct dpll_pin_ref *ref;
798 
799 	ref = xa_load(&dpll->pin_refs, pin->pin_idx);
800 	if (!ref)
801 		return NULL;
802 	reg = dpll_pin_registration_first(ref);
803 	return reg->priv;
804 }
805 
806 void *dpll_pin_on_pin_priv(struct dpll_pin *parent,
807 			   struct dpll_pin *pin)
808 {
809 	struct dpll_pin_registration *reg;
810 	struct dpll_pin_ref *ref;
811 
812 	ref = xa_load(&pin->parent_refs, parent->pin_idx);
813 	if (!ref)
814 		return NULL;
815 	reg = dpll_pin_registration_first(ref);
816 	return reg->priv;
817 }
818 
819 const struct dpll_pin_ops *dpll_pin_ops(struct dpll_pin_ref *ref)
820 {
821 	struct dpll_pin_registration *reg;
822 
823 	reg = dpll_pin_registration_first(ref);
824 	return reg->ops;
825 }
826 
827 static int __init dpll_init(void)
828 {
829 	int ret;
830 
831 	ret = genl_register_family(&dpll_nl_family);
832 	if (ret)
833 		goto error;
834 
835 	return 0;
836 
837 error:
838 	mutex_destroy(&dpll_lock);
839 	return ret;
840 }
841 
842 static void __exit dpll_exit(void)
843 {
844 	genl_unregister_family(&dpll_nl_family);
845 	mutex_destroy(&dpll_lock);
846 }
847 
848 subsys_initcall(dpll_init);
849 module_exit(dpll_exit);
850