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  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 */
 20DEFINE_MUTEX(dpll_lock);
 21
 22DEFINE_XARRAY_FLAGS(dpll_device_xa, XA_FLAGS_ALLOC);
 23DEFINE_XARRAY_FLAGS(dpll_pin_xa, XA_FLAGS_ALLOC);
 24
 25static u32 dpll_device_xa_id;
 26static 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
 33struct dpll_device_registration {
 34	struct list_head list;
 35	const struct dpll_device_ops *ops;
 36	void *priv;
 37};
 38
 39struct dpll_pin_registration {
 40	struct list_head list;
 41	const struct dpll_pin_ops *ops;
 42	void *priv;
 43};
 44
 45struct dpll_device *dpll_device_get_by_id(int id)
 46{
 47	if (xa_get_mark(&dpll_device_xa, id, DPLL_REGISTERED))
 48		return xa_load(&dpll_device_xa, id);
 49
 50	return NULL;
 51}
 52
 53static struct dpll_pin_registration *
 54dpll_pin_registration_find(struct dpll_pin_ref *ref,
 55			   const struct dpll_pin_ops *ops, void *priv)
 56{
 57	struct dpll_pin_registration *reg;
 58
 59	list_for_each_entry(reg, &ref->registration_list, list) {
 60		if (reg->ops == ops && reg->priv == priv)
 61			return reg;
 62	}
 63	return NULL;
 64}
 65
 66static int
 67dpll_xa_ref_pin_add(struct xarray *xa_pins, struct dpll_pin *pin,
 68		    const struct dpll_pin_ops *ops, void *priv)
 69{
 70	struct dpll_pin_registration *reg;
 71	struct dpll_pin_ref *ref;
 72	bool ref_exists = false;
 73	unsigned long i;
 74	int ret;
 75
 76	xa_for_each(xa_pins, i, ref) {
 77		if (ref->pin != pin)
 78			continue;
 79		reg = dpll_pin_registration_find(ref, ops, priv);
 80		if (reg) {
 81			refcount_inc(&ref->refcount);
 82			return 0;
 83		}
 84		ref_exists = true;
 85		break;
 86	}
 87
 88	if (!ref_exists) {
 89		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
 90		if (!ref)
 91			return -ENOMEM;
 92		ref->pin = pin;
 93		INIT_LIST_HEAD(&ref->registration_list);
 94		ret = xa_insert(xa_pins, pin->pin_idx, ref, GFP_KERNEL);
 95		if (ret) {
 96			kfree(ref);
 97			return ret;
 98		}
 99		refcount_set(&ref->refcount, 1);
100	}
101
102	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
103	if (!reg) {
104		if (!ref_exists) {
105			xa_erase(xa_pins, pin->pin_idx);
106			kfree(ref);
107		}
108		return -ENOMEM;
109	}
110	reg->ops = ops;
111	reg->priv = priv;
112	if (ref_exists)
113		refcount_inc(&ref->refcount);
114	list_add_tail(&reg->list, &ref->registration_list);
115
116	return 0;
117}
118
119static int dpll_xa_ref_pin_del(struct xarray *xa_pins, struct dpll_pin *pin,
120			       const struct dpll_pin_ops *ops, void *priv)
121{
122	struct dpll_pin_registration *reg;
123	struct dpll_pin_ref *ref;
124	unsigned long i;
125
126	xa_for_each(xa_pins, i, ref) {
127		if (ref->pin != pin)
128			continue;
129		reg = dpll_pin_registration_find(ref, ops, priv);
130		if (WARN_ON(!reg))
131			return -EINVAL;
132		if (refcount_dec_and_test(&ref->refcount)) {
133			list_del(&reg->list);
134			kfree(reg);
135			xa_erase(xa_pins, i);
136			WARN_ON(!list_empty(&ref->registration_list));
137			kfree(ref);
138		}
139		return 0;
140	}
141
142	return -EINVAL;
143}
144
145static int
146dpll_xa_ref_dpll_add(struct xarray *xa_dplls, struct dpll_device *dpll,
147		     const struct dpll_pin_ops *ops, void *priv)
148{
149	struct dpll_pin_registration *reg;
150	struct dpll_pin_ref *ref;
151	bool ref_exists = false;
152	unsigned long i;
153	int ret;
154
155	xa_for_each(xa_dplls, i, ref) {
156		if (ref->dpll != dpll)
157			continue;
158		reg = dpll_pin_registration_find(ref, ops, priv);
159		if (reg) {
160			refcount_inc(&ref->refcount);
161			return 0;
162		}
163		ref_exists = true;
164		break;
165	}
166
167	if (!ref_exists) {
168		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
169		if (!ref)
170			return -ENOMEM;
171		ref->dpll = dpll;
172		INIT_LIST_HEAD(&ref->registration_list);
173		ret = xa_insert(xa_dplls, dpll->id, ref, GFP_KERNEL);
174		if (ret) {
175			kfree(ref);
176			return ret;
177		}
178		refcount_set(&ref->refcount, 1);
179	}
180
181	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
182	if (!reg) {
183		if (!ref_exists) {
184			xa_erase(xa_dplls, dpll->id);
185			kfree(ref);
186		}
187		return -ENOMEM;
188	}
189	reg->ops = ops;
190	reg->priv = priv;
191	if (ref_exists)
192		refcount_inc(&ref->refcount);
193	list_add_tail(&reg->list, &ref->registration_list);
194
195	return 0;
196}
197
198static void
199dpll_xa_ref_dpll_del(struct xarray *xa_dplls, struct dpll_device *dpll,
200		     const struct dpll_pin_ops *ops, void *priv)
201{
202	struct dpll_pin_registration *reg;
203	struct dpll_pin_ref *ref;
204	unsigned long i;
205
206	xa_for_each(xa_dplls, i, ref) {
207		if (ref->dpll != dpll)
208			continue;
209		reg = dpll_pin_registration_find(ref, ops, priv);
210		if (WARN_ON(!reg))
211			return;
212		if (refcount_dec_and_test(&ref->refcount)) {
213			list_del(&reg->list);
214			kfree(reg);
215			xa_erase(xa_dplls, i);
216			WARN_ON(!list_empty(&ref->registration_list));
217			kfree(ref);
218		}
219		return;
220	}
221}
222
223struct dpll_pin_ref *dpll_xa_ref_dpll_first(struct xarray *xa_refs)
224{
225	struct dpll_pin_ref *ref;
226	unsigned long i = 0;
227
228	ref = xa_find(xa_refs, &i, ULONG_MAX, XA_PRESENT);
229	WARN_ON(!ref);
230	return ref;
231}
232
233static struct dpll_device *
234dpll_device_alloc(const u64 clock_id, u32 device_idx, struct module *module)
235{
236	struct dpll_device *dpll;
237	int ret;
238
239	dpll = kzalloc(sizeof(*dpll), GFP_KERNEL);
240	if (!dpll)
241		return ERR_PTR(-ENOMEM);
242	refcount_set(&dpll->refcount, 1);
243	INIT_LIST_HEAD(&dpll->registration_list);
244	dpll->device_idx = device_idx;
245	dpll->clock_id = clock_id;
246	dpll->module = module;
247	ret = xa_alloc_cyclic(&dpll_device_xa, &dpll->id, dpll, xa_limit_32b,
248			      &dpll_device_xa_id, GFP_KERNEL);
249	if (ret < 0) {
250		kfree(dpll);
251		return ERR_PTR(ret);
252	}
253	xa_init_flags(&dpll->pin_refs, XA_FLAGS_ALLOC);
254
255	return dpll;
256}
257
258/**
259 * dpll_device_get - find existing or create new dpll device
260 * @clock_id: clock_id of creator
261 * @device_idx: idx given by device driver
262 * @module: reference to registering module
263 *
264 * Get existing object of a dpll device, unique for given arguments.
265 * Create new if doesn't exist yet.
266 *
267 * Context: Acquires a lock (dpll_lock)
268 * Return:
269 * * valid dpll_device struct pointer if succeeded
270 * * ERR_PTR(X) - error
271 */
272struct dpll_device *
273dpll_device_get(u64 clock_id, u32 device_idx, struct module *module)
274{
275	struct dpll_device *dpll, *ret = NULL;
276	unsigned long index;
277
278	mutex_lock(&dpll_lock);
279	xa_for_each(&dpll_device_xa, index, dpll) {
280		if (dpll->clock_id == clock_id &&
281		    dpll->device_idx == device_idx &&
282		    dpll->module == module) {
283			ret = dpll;
284			refcount_inc(&ret->refcount);
285			break;
286		}
287	}
288	if (!ret)
289		ret = dpll_device_alloc(clock_id, device_idx, module);
290	mutex_unlock(&dpll_lock);
291
292	return ret;
293}
294EXPORT_SYMBOL_GPL(dpll_device_get);
295
296/**
297 * dpll_device_put - decrease the refcount and free memory if possible
298 * @dpll: dpll_device struct pointer
299 *
300 * Context: Acquires a lock (dpll_lock)
301 * Drop reference for a dpll device, if all references are gone, delete
302 * dpll device object.
303 */
304void dpll_device_put(struct dpll_device *dpll)
305{
306	mutex_lock(&dpll_lock);
307	if (refcount_dec_and_test(&dpll->refcount)) {
308		ASSERT_DPLL_NOT_REGISTERED(dpll);
309		WARN_ON_ONCE(!xa_empty(&dpll->pin_refs));
310		xa_destroy(&dpll->pin_refs);
311		xa_erase(&dpll_device_xa, dpll->id);
312		WARN_ON(!list_empty(&dpll->registration_list));
313		kfree(dpll);
314	}
315	mutex_unlock(&dpll_lock);
316}
317EXPORT_SYMBOL_GPL(dpll_device_put);
318
319static struct dpll_device_registration *
320dpll_device_registration_find(struct dpll_device *dpll,
321			      const struct dpll_device_ops *ops, void *priv)
322{
323	struct dpll_device_registration *reg;
324
325	list_for_each_entry(reg, &dpll->registration_list, list) {
326		if (reg->ops == ops && reg->priv == priv)
327			return reg;
328	}
329	return NULL;
330}
331
332/**
333 * dpll_device_register - register the dpll device in the subsystem
334 * @dpll: pointer to a dpll
335 * @type: type of a dpll
336 * @ops: ops for a dpll device
337 * @priv: pointer to private information of owner
338 *
339 * Make dpll device available for user space.
340 *
341 * Context: Acquires a lock (dpll_lock)
342 * Return:
343 * * 0 on success
344 * * negative - error value
345 */
346int dpll_device_register(struct dpll_device *dpll, enum dpll_type type,
347			 const struct dpll_device_ops *ops, void *priv)
348{
349	struct dpll_device_registration *reg;
350	bool first_registration = false;
351
352	if (WARN_ON(!ops))
353		return -EINVAL;
354	if (WARN_ON(!ops->mode_get))
355		return -EINVAL;
356	if (WARN_ON(!ops->lock_status_get))
357		return -EINVAL;
358	if (WARN_ON(type < DPLL_TYPE_PPS || type > DPLL_TYPE_MAX))
359		return -EINVAL;
360
361	mutex_lock(&dpll_lock);
362	reg = dpll_device_registration_find(dpll, ops, priv);
363	if (reg) {
364		mutex_unlock(&dpll_lock);
365		return -EEXIST;
366	}
367
368	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
369	if (!reg) {
370		mutex_unlock(&dpll_lock);
371		return -ENOMEM;
372	}
373	reg->ops = ops;
374	reg->priv = priv;
375	dpll->type = type;
376	first_registration = list_empty(&dpll->registration_list);
377	list_add_tail(&reg->list, &dpll->registration_list);
378	if (!first_registration) {
379		mutex_unlock(&dpll_lock);
380		return 0;
381	}
382
383	xa_set_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
384	dpll_device_create_ntf(dpll);
385	mutex_unlock(&dpll_lock);
386
387	return 0;
388}
389EXPORT_SYMBOL_GPL(dpll_device_register);
390
391/**
392 * dpll_device_unregister - unregister dpll device
393 * @dpll: registered dpll pointer
394 * @ops: ops for a dpll device
395 * @priv: pointer to private information of owner
396 *
397 * Unregister device, make it unavailable for userspace.
398 * Note: It does not free the memory
399 * Context: Acquires a lock (dpll_lock)
400 */
401void dpll_device_unregister(struct dpll_device *dpll,
402			    const struct dpll_device_ops *ops, void *priv)
403{
404	struct dpll_device_registration *reg;
405
406	mutex_lock(&dpll_lock);
407	ASSERT_DPLL_REGISTERED(dpll);
408	dpll_device_delete_ntf(dpll);
409	reg = dpll_device_registration_find(dpll, ops, priv);
410	if (WARN_ON(!reg)) {
411		mutex_unlock(&dpll_lock);
412		return;
413	}
414	list_del(&reg->list);
415	kfree(reg);
416
417	if (!list_empty(&dpll->registration_list)) {
418		mutex_unlock(&dpll_lock);
419		return;
420	}
421	xa_clear_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
422	mutex_unlock(&dpll_lock);
423}
424EXPORT_SYMBOL_GPL(dpll_device_unregister);
425
426static void dpll_pin_prop_free(struct dpll_pin_properties *prop)
427{
428	kfree(prop->package_label);
429	kfree(prop->panel_label);
430	kfree(prop->board_label);
431	kfree(prop->freq_supported);
432}
433
434static int dpll_pin_prop_dup(const struct dpll_pin_properties *src,
435			     struct dpll_pin_properties *dst)
436{
437	memcpy(dst, src, sizeof(*dst));
438	if (src->freq_supported && src->freq_supported_num) {
439		size_t freq_size = src->freq_supported_num *
440				   sizeof(*src->freq_supported);
441		dst->freq_supported = kmemdup(src->freq_supported,
442					      freq_size, GFP_KERNEL);
443		if (!src->freq_supported)
444			return -ENOMEM;
445	}
446	if (src->board_label) {
447		dst->board_label = kstrdup(src->board_label, GFP_KERNEL);
448		if (!dst->board_label)
449			goto err_board_label;
450	}
451	if (src->panel_label) {
452		dst->panel_label = kstrdup(src->panel_label, GFP_KERNEL);
453		if (!dst->panel_label)
454			goto err_panel_label;
455	}
456	if (src->package_label) {
457		dst->package_label = kstrdup(src->package_label, GFP_KERNEL);
458		if (!dst->package_label)
459			goto err_package_label;
460	}
461
462	return 0;
463
464err_package_label:
465	kfree(dst->panel_label);
466err_panel_label:
467	kfree(dst->board_label);
468err_board_label:
469	kfree(dst->freq_supported);
470	return -ENOMEM;
471}
472
473static struct dpll_pin *
474dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
475	       const struct dpll_pin_properties *prop)
476{
477	struct dpll_pin *pin;
478	int ret;
479
480	pin = kzalloc(sizeof(*pin), GFP_KERNEL);
481	if (!pin)
482		return ERR_PTR(-ENOMEM);
483	pin->pin_idx = pin_idx;
484	pin->clock_id = clock_id;
485	pin->module = module;
486	if (WARN_ON(prop->type < DPLL_PIN_TYPE_MUX ||
487		    prop->type > DPLL_PIN_TYPE_MAX)) {
488		ret = -EINVAL;
489		goto err_pin_prop;
490	}
491	ret = dpll_pin_prop_dup(prop, &pin->prop);
492	if (ret)
493		goto err_pin_prop;
494	refcount_set(&pin->refcount, 1);
495	xa_init_flags(&pin->dpll_refs, XA_FLAGS_ALLOC);
496	xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
497	ret = xa_alloc_cyclic(&dpll_pin_xa, &pin->id, pin, xa_limit_32b,
498			      &dpll_pin_xa_id, GFP_KERNEL);
499	if (ret)
500		goto err_xa_alloc;
501	return pin;
502err_xa_alloc:
503	xa_destroy(&pin->dpll_refs);
504	xa_destroy(&pin->parent_refs);
505	dpll_pin_prop_free(&pin->prop);
506err_pin_prop:
507	kfree(pin);
508	return ERR_PTR(ret);
509}
510
511static void dpll_netdev_pin_assign(struct net_device *dev, struct dpll_pin *dpll_pin)
512{
513	rtnl_lock();
514	rcu_assign_pointer(dev->dpll_pin, dpll_pin);
515	rtnl_unlock();
516}
517
518void dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)
519{
520	WARN_ON(!dpll_pin);
521	dpll_netdev_pin_assign(dev, dpll_pin);
522}
523EXPORT_SYMBOL(dpll_netdev_pin_set);
524
525void dpll_netdev_pin_clear(struct net_device *dev)
526{
527	dpll_netdev_pin_assign(dev, NULL);
528}
529EXPORT_SYMBOL(dpll_netdev_pin_clear);
530
531/**
532 * dpll_pin_get - find existing or create new dpll pin
533 * @clock_id: clock_id of creator
534 * @pin_idx: idx given by dev driver
535 * @module: reference to registering module
536 * @prop: dpll pin properties
537 *
538 * Get existing object of a pin (unique for given arguments) or create new
539 * if doesn't exist yet.
540 *
541 * Context: Acquires a lock (dpll_lock)
542 * Return:
543 * * valid allocated dpll_pin struct pointer if succeeded
544 * * ERR_PTR(X) - error
545 */
546struct dpll_pin *
547dpll_pin_get(u64 clock_id, u32 pin_idx, struct module *module,
548	     const struct dpll_pin_properties *prop)
549{
550	struct dpll_pin *pos, *ret = NULL;
551	unsigned long i;
552
553	mutex_lock(&dpll_lock);
554	xa_for_each(&dpll_pin_xa, i, pos) {
555		if (pos->clock_id == clock_id &&
556		    pos->pin_idx == pin_idx &&
557		    pos->module == module) {
558			ret = pos;
559			refcount_inc(&ret->refcount);
560			break;
561		}
562	}
563	if (!ret)
564		ret = dpll_pin_alloc(clock_id, pin_idx, module, prop);
565	mutex_unlock(&dpll_lock);
566
567	return ret;
568}
569EXPORT_SYMBOL_GPL(dpll_pin_get);
570
571/**
572 * dpll_pin_put - decrease the refcount and free memory if possible
573 * @pin: pointer to a pin to be put
574 *
575 * Drop reference for a pin, if all references are gone, delete pin object.
576 *
577 * Context: Acquires a lock (dpll_lock)
578 */
579void dpll_pin_put(struct dpll_pin *pin)
580{
581	mutex_lock(&dpll_lock);
582	if (refcount_dec_and_test(&pin->refcount)) {
583		xa_destroy(&pin->dpll_refs);
584		xa_destroy(&pin->parent_refs);
585		xa_erase(&dpll_pin_xa, pin->id);
586		dpll_pin_prop_free(&pin->prop);
587		kfree_rcu(pin, rcu);
588	}
589	mutex_unlock(&dpll_lock);
590}
591EXPORT_SYMBOL_GPL(dpll_pin_put);
592
593static int
594__dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
595		    const struct dpll_pin_ops *ops, void *priv)
596{
597	int ret;
598
599	ret = dpll_xa_ref_pin_add(&dpll->pin_refs, pin, ops, priv);
600	if (ret)
601		return ret;
602	ret = dpll_xa_ref_dpll_add(&pin->dpll_refs, dpll, ops, priv);
603	if (ret)
604		goto ref_pin_del;
605	xa_set_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
606	dpll_pin_create_ntf(pin);
607
608	return ret;
609
610ref_pin_del:
611	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
612	return ret;
613}
614
615/**
616 * dpll_pin_register - register the dpll pin in the subsystem
617 * @dpll: pointer to a dpll
618 * @pin: pointer to a dpll pin
619 * @ops: ops for a dpll pin ops
620 * @priv: pointer to private information of owner
621 *
622 * Context: Acquires a lock (dpll_lock)
623 * Return:
624 * * 0 on success
625 * * negative - error value
626 */
627int
628dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
629		  const struct dpll_pin_ops *ops, void *priv)
630{
631	int ret;
632
633	if (WARN_ON(!ops) ||
634	    WARN_ON(!ops->state_on_dpll_get) ||
635	    WARN_ON(!ops->direction_get))
636		return -EINVAL;
637
638	mutex_lock(&dpll_lock);
639	if (WARN_ON(!(dpll->module == pin->module &&
640		      dpll->clock_id == pin->clock_id)))
641		ret = -EINVAL;
642	else
643		ret = __dpll_pin_register(dpll, pin, ops, priv);
644	mutex_unlock(&dpll_lock);
645
646	return ret;
647}
648EXPORT_SYMBOL_GPL(dpll_pin_register);
649
650static void
651__dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
652		      const struct dpll_pin_ops *ops, void *priv)
653{
654	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
655	dpll_xa_ref_dpll_del(&pin->dpll_refs, dpll, ops, priv);
656	if (xa_empty(&pin->dpll_refs))
657		xa_clear_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
658}
659
660/**
661 * dpll_pin_unregister - unregister dpll pin from dpll device
662 * @dpll: registered dpll pointer
663 * @pin: pointer to a pin
664 * @ops: ops for a dpll pin
665 * @priv: pointer to private information of owner
666 *
667 * Note: It does not free the memory
668 * Context: Acquires a lock (dpll_lock)
669 */
670void dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
671			 const struct dpll_pin_ops *ops, void *priv)
672{
673	if (WARN_ON(xa_empty(&dpll->pin_refs)))
674		return;
675	if (WARN_ON(!xa_empty(&pin->parent_refs)))
676		return;
677
678	mutex_lock(&dpll_lock);
679	dpll_pin_delete_ntf(pin);
680	__dpll_pin_unregister(dpll, pin, ops, priv);
681	mutex_unlock(&dpll_lock);
682}
683EXPORT_SYMBOL_GPL(dpll_pin_unregister);
684
685/**
686 * dpll_pin_on_pin_register - register a pin with a parent pin
687 * @parent: pointer to a parent pin
688 * @pin: pointer to a pin
689 * @ops: ops for a dpll pin
690 * @priv: pointer to private information of owner
691 *
692 * Register a pin with a parent pin, create references between them and
693 * between newly registered pin and dplls connected with a parent pin.
694 *
695 * Context: Acquires a lock (dpll_lock)
696 * Return:
697 * * 0 on success
698 * * negative - error value
699 */
700int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
701			     const struct dpll_pin_ops *ops, void *priv)
702{
703	struct dpll_pin_ref *ref;
704	unsigned long i, stop;
705	int ret;
706
707	if (WARN_ON(parent->prop.type != DPLL_PIN_TYPE_MUX))
708		return -EINVAL;
709
710	if (WARN_ON(!ops) ||
711	    WARN_ON(!ops->state_on_pin_get) ||
712	    WARN_ON(!ops->direction_get))
713		return -EINVAL;
714
715	mutex_lock(&dpll_lock);
716	ret = dpll_xa_ref_pin_add(&pin->parent_refs, parent, ops, priv);
717	if (ret)
718		goto unlock;
719	refcount_inc(&pin->refcount);
720	xa_for_each(&parent->dpll_refs, i, ref) {
721		ret = __dpll_pin_register(ref->dpll, pin, ops, priv);
722		if (ret) {
723			stop = i;
724			goto dpll_unregister;
725		}
726		dpll_pin_create_ntf(pin);
727	}
728	mutex_unlock(&dpll_lock);
729
730	return ret;
731
732dpll_unregister:
733	xa_for_each(&parent->dpll_refs, i, ref)
734		if (i < stop) {
735			__dpll_pin_unregister(ref->dpll, pin, ops, priv);
736			dpll_pin_delete_ntf(pin);
737		}
738	refcount_dec(&pin->refcount);
739	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
740unlock:
741	mutex_unlock(&dpll_lock);
742	return ret;
743}
744EXPORT_SYMBOL_GPL(dpll_pin_on_pin_register);
745
746/**
747 * dpll_pin_on_pin_unregister - unregister dpll pin from a parent pin
748 * @parent: pointer to a parent pin
749 * @pin: pointer to a pin
750 * @ops: ops for a dpll pin
751 * @priv: pointer to private information of owner
752 *
753 * Context: Acquires a lock (dpll_lock)
754 * Note: It does not free the memory
755 */
756void dpll_pin_on_pin_unregister(struct dpll_pin *parent, struct dpll_pin *pin,
757				const struct dpll_pin_ops *ops, void *priv)
758{
759	struct dpll_pin_ref *ref;
760	unsigned long i;
761
762	mutex_lock(&dpll_lock);
763	dpll_pin_delete_ntf(pin);
764	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
765	refcount_dec(&pin->refcount);
766	xa_for_each(&pin->dpll_refs, i, ref)
767		__dpll_pin_unregister(ref->dpll, pin, ops, priv);
768	mutex_unlock(&dpll_lock);
769}
770EXPORT_SYMBOL_GPL(dpll_pin_on_pin_unregister);
771
772static struct dpll_device_registration *
773dpll_device_registration_first(struct dpll_device *dpll)
774{
775	struct dpll_device_registration *reg;
776
777	reg = list_first_entry_or_null((struct list_head *)&dpll->registration_list,
778				       struct dpll_device_registration, list);
779	WARN_ON(!reg);
780	return reg;
781}
782
783void *dpll_priv(struct dpll_device *dpll)
784{
785	struct dpll_device_registration *reg;
786
787	reg = dpll_device_registration_first(dpll);
788	return reg->priv;
789}
790
791const struct dpll_device_ops *dpll_device_ops(struct dpll_device *dpll)
792{
793	struct dpll_device_registration *reg;
794
795	reg = dpll_device_registration_first(dpll);
796	return reg->ops;
797}
798
799static struct dpll_pin_registration *
800dpll_pin_registration_first(struct dpll_pin_ref *ref)
801{
802	struct dpll_pin_registration *reg;
803
804	reg = list_first_entry_or_null(&ref->registration_list,
805				       struct dpll_pin_registration, list);
806	WARN_ON(!reg);
807	return reg;
808}
809
810void *dpll_pin_on_dpll_priv(struct dpll_device *dpll,
811			    struct dpll_pin *pin)
812{
813	struct dpll_pin_registration *reg;
814	struct dpll_pin_ref *ref;
815
816	ref = xa_load(&dpll->pin_refs, pin->pin_idx);
817	if (!ref)
818		return NULL;
819	reg = dpll_pin_registration_first(ref);
820	return reg->priv;
821}
822
823void *dpll_pin_on_pin_priv(struct dpll_pin *parent,
824			   struct dpll_pin *pin)
825{
826	struct dpll_pin_registration *reg;
827	struct dpll_pin_ref *ref;
828
829	ref = xa_load(&pin->parent_refs, parent->pin_idx);
830	if (!ref)
831		return NULL;
832	reg = dpll_pin_registration_first(ref);
833	return reg->priv;
834}
835
836const struct dpll_pin_ops *dpll_pin_ops(struct dpll_pin_ref *ref)
837{
838	struct dpll_pin_registration *reg;
839
840	reg = dpll_pin_registration_first(ref);
841	return reg->ops;
842}
843
844static int __init dpll_init(void)
845{
846	int ret;
847
848	ret = genl_register_family(&dpll_nl_family);
849	if (ret)
850		goto error;
851
852	return 0;
853
854error:
855	mutex_destroy(&dpll_lock);
856	return ret;
857}
858
859static void __exit dpll_exit(void)
860{
861	genl_unregister_family(&dpll_nl_family);
862	mutex_destroy(&dpll_lock);
863}
864
865subsys_initcall(dpll_init);
866module_exit(dpll_exit);