xref: /linux/drivers/dpll/dpll_core.c (revision 297dc37a1e65f2f7378c2f755516d2c8c1db2c32)
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 
33 struct dpll_device_registration {
34 	struct list_head list;
35 	const struct dpll_device_ops *ops;
36 	void *priv;
37 };
38 
39 struct dpll_pin_registration {
40 	struct list_head list;
41 	const struct dpll_pin_ops *ops;
42 	void *priv;
43 };
44 
45 struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
46 {
47 	return rcu_dereference_rtnl(dev->dpll_pin);
48 }
49 
50 struct dpll_device *dpll_device_get_by_id(int id)
51 {
52 	if (xa_get_mark(&dpll_device_xa, id, DPLL_REGISTERED))
53 		return xa_load(&dpll_device_xa, id);
54 
55 	return NULL;
56 }
57 
58 static struct dpll_pin_registration *
59 dpll_pin_registration_find(struct dpll_pin_ref *ref,
60 			   const struct dpll_pin_ops *ops, void *priv)
61 {
62 	struct dpll_pin_registration *reg;
63 
64 	list_for_each_entry(reg, &ref->registration_list, list) {
65 		if (reg->ops == ops && reg->priv == priv)
66 			return reg;
67 	}
68 	return NULL;
69 }
70 
71 static int
72 dpll_xa_ref_pin_add(struct xarray *xa_pins, struct dpll_pin *pin,
73 		    const struct dpll_pin_ops *ops, void *priv)
74 {
75 	struct dpll_pin_registration *reg;
76 	struct dpll_pin_ref *ref;
77 	bool ref_exists = false;
78 	unsigned long i;
79 	int ret;
80 
81 	xa_for_each(xa_pins, i, ref) {
82 		if (ref->pin != pin)
83 			continue;
84 		reg = dpll_pin_registration_find(ref, ops, priv);
85 		if (reg) {
86 			refcount_inc(&ref->refcount);
87 			return 0;
88 		}
89 		ref_exists = true;
90 		break;
91 	}
92 
93 	if (!ref_exists) {
94 		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
95 		if (!ref)
96 			return -ENOMEM;
97 		ref->pin = pin;
98 		INIT_LIST_HEAD(&ref->registration_list);
99 		ret = xa_insert(xa_pins, pin->pin_idx, ref, GFP_KERNEL);
100 		if (ret) {
101 			kfree(ref);
102 			return ret;
103 		}
104 		refcount_set(&ref->refcount, 1);
105 	}
106 
107 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
108 	if (!reg) {
109 		if (!ref_exists) {
110 			xa_erase(xa_pins, pin->pin_idx);
111 			kfree(ref);
112 		}
113 		return -ENOMEM;
114 	}
115 	reg->ops = ops;
116 	reg->priv = priv;
117 	if (ref_exists)
118 		refcount_inc(&ref->refcount);
119 	list_add_tail(&reg->list, &ref->registration_list);
120 
121 	return 0;
122 }
123 
124 static int dpll_xa_ref_pin_del(struct xarray *xa_pins, struct dpll_pin *pin,
125 			       const struct dpll_pin_ops *ops, void *priv)
126 {
127 	struct dpll_pin_registration *reg;
128 	struct dpll_pin_ref *ref;
129 	unsigned long i;
130 
131 	xa_for_each(xa_pins, i, ref) {
132 		if (ref->pin != pin)
133 			continue;
134 		reg = dpll_pin_registration_find(ref, ops, priv);
135 		if (WARN_ON(!reg))
136 			return -EINVAL;
137 		if (refcount_dec_and_test(&ref->refcount)) {
138 			list_del(&reg->list);
139 			kfree(reg);
140 			xa_erase(xa_pins, i);
141 			WARN_ON(!list_empty(&ref->registration_list));
142 			kfree(ref);
143 		}
144 		return 0;
145 	}
146 
147 	return -EINVAL;
148 }
149 
150 static int
151 dpll_xa_ref_dpll_add(struct xarray *xa_dplls, struct dpll_device *dpll,
152 		     const struct dpll_pin_ops *ops, void *priv)
153 {
154 	struct dpll_pin_registration *reg;
155 	struct dpll_pin_ref *ref;
156 	bool ref_exists = false;
157 	unsigned long i;
158 	int ret;
159 
160 	xa_for_each(xa_dplls, i, ref) {
161 		if (ref->dpll != dpll)
162 			continue;
163 		reg = dpll_pin_registration_find(ref, ops, priv);
164 		if (reg) {
165 			refcount_inc(&ref->refcount);
166 			return 0;
167 		}
168 		ref_exists = true;
169 		break;
170 	}
171 
172 	if (!ref_exists) {
173 		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
174 		if (!ref)
175 			return -ENOMEM;
176 		ref->dpll = dpll;
177 		INIT_LIST_HEAD(&ref->registration_list);
178 		ret = xa_insert(xa_dplls, dpll->id, ref, GFP_KERNEL);
179 		if (ret) {
180 			kfree(ref);
181 			return ret;
182 		}
183 		refcount_set(&ref->refcount, 1);
184 	}
185 
186 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
187 	if (!reg) {
188 		if (!ref_exists) {
189 			xa_erase(xa_dplls, dpll->id);
190 			kfree(ref);
191 		}
192 		return -ENOMEM;
193 	}
194 	reg->ops = ops;
195 	reg->priv = priv;
196 	if (ref_exists)
197 		refcount_inc(&ref->refcount);
198 	list_add_tail(&reg->list, &ref->registration_list);
199 
200 	return 0;
201 }
202 
203 static void
204 dpll_xa_ref_dpll_del(struct xarray *xa_dplls, struct dpll_device *dpll,
205 		     const struct dpll_pin_ops *ops, void *priv)
206 {
207 	struct dpll_pin_registration *reg;
208 	struct dpll_pin_ref *ref;
209 	unsigned long i;
210 
211 	xa_for_each(xa_dplls, i, ref) {
212 		if (ref->dpll != dpll)
213 			continue;
214 		reg = dpll_pin_registration_find(ref, ops, priv);
215 		if (WARN_ON(!reg))
216 			return;
217 		if (refcount_dec_and_test(&ref->refcount)) {
218 			list_del(&reg->list);
219 			kfree(reg);
220 			xa_erase(xa_dplls, i);
221 			WARN_ON(!list_empty(&ref->registration_list));
222 			kfree(ref);
223 		}
224 		return;
225 	}
226 }
227 
228 struct dpll_pin_ref *dpll_xa_ref_dpll_first(struct xarray *xa_refs)
229 {
230 	struct dpll_pin_ref *ref;
231 	unsigned long i = 0;
232 
233 	ref = xa_find(xa_refs, &i, ULONG_MAX, XA_PRESENT);
234 	WARN_ON(!ref);
235 	return ref;
236 }
237 
238 static struct dpll_device *
239 dpll_device_alloc(const u64 clock_id, u32 device_idx, struct module *module)
240 {
241 	struct dpll_device *dpll;
242 	int ret;
243 
244 	dpll = kzalloc(sizeof(*dpll), GFP_KERNEL);
245 	if (!dpll)
246 		return ERR_PTR(-ENOMEM);
247 	refcount_set(&dpll->refcount, 1);
248 	INIT_LIST_HEAD(&dpll->registration_list);
249 	dpll->device_idx = device_idx;
250 	dpll->clock_id = clock_id;
251 	dpll->module = module;
252 	ret = xa_alloc_cyclic(&dpll_device_xa, &dpll->id, dpll, xa_limit_32b,
253 			      &dpll_device_xa_id, GFP_KERNEL);
254 	if (ret < 0) {
255 		kfree(dpll);
256 		return ERR_PTR(ret);
257 	}
258 	xa_init_flags(&dpll->pin_refs, XA_FLAGS_ALLOC);
259 
260 	return dpll;
261 }
262 
263 /**
264  * dpll_device_get - find existing or create new dpll device
265  * @clock_id: clock_id of creator
266  * @device_idx: idx given by device driver
267  * @module: reference to registering module
268  *
269  * Get existing object of a dpll device, unique for given arguments.
270  * Create new if doesn't exist yet.
271  *
272  * Context: Acquires a lock (dpll_lock)
273  * Return:
274  * * valid dpll_device struct pointer if succeeded
275  * * ERR_PTR(X) - error
276  */
277 struct dpll_device *
278 dpll_device_get(u64 clock_id, u32 device_idx, struct module *module)
279 {
280 	struct dpll_device *dpll, *ret = NULL;
281 	unsigned long index;
282 
283 	mutex_lock(&dpll_lock);
284 	xa_for_each(&dpll_device_xa, index, dpll) {
285 		if (dpll->clock_id == clock_id &&
286 		    dpll->device_idx == device_idx &&
287 		    dpll->module == module) {
288 			ret = dpll;
289 			refcount_inc(&ret->refcount);
290 			break;
291 		}
292 	}
293 	if (!ret)
294 		ret = dpll_device_alloc(clock_id, device_idx, module);
295 	mutex_unlock(&dpll_lock);
296 
297 	return ret;
298 }
299 EXPORT_SYMBOL_GPL(dpll_device_get);
300 
301 /**
302  * dpll_device_put - decrease the refcount and free memory if possible
303  * @dpll: dpll_device struct pointer
304  *
305  * Context: Acquires a lock (dpll_lock)
306  * Drop reference for a dpll device, if all references are gone, delete
307  * dpll device object.
308  */
309 void dpll_device_put(struct dpll_device *dpll)
310 {
311 	mutex_lock(&dpll_lock);
312 	if (refcount_dec_and_test(&dpll->refcount)) {
313 		ASSERT_DPLL_NOT_REGISTERED(dpll);
314 		WARN_ON_ONCE(!xa_empty(&dpll->pin_refs));
315 		xa_destroy(&dpll->pin_refs);
316 		xa_erase(&dpll_device_xa, dpll->id);
317 		WARN_ON(!list_empty(&dpll->registration_list));
318 		kfree(dpll);
319 	}
320 	mutex_unlock(&dpll_lock);
321 }
322 EXPORT_SYMBOL_GPL(dpll_device_put);
323 
324 static struct dpll_device_registration *
325 dpll_device_registration_find(struct dpll_device *dpll,
326 			      const struct dpll_device_ops *ops, void *priv)
327 {
328 	struct dpll_device_registration *reg;
329 
330 	list_for_each_entry(reg, &dpll->registration_list, list) {
331 		if (reg->ops == ops && reg->priv == priv)
332 			return reg;
333 	}
334 	return NULL;
335 }
336 
337 /**
338  * dpll_device_register - register the dpll device in the subsystem
339  * @dpll: pointer to a dpll
340  * @type: type of a dpll
341  * @ops: ops for a dpll device
342  * @priv: pointer to private information of owner
343  *
344  * Make dpll device available for user space.
345  *
346  * Context: Acquires a lock (dpll_lock)
347  * Return:
348  * * 0 on success
349  * * negative - error value
350  */
351 int dpll_device_register(struct dpll_device *dpll, enum dpll_type type,
352 			 const struct dpll_device_ops *ops, void *priv)
353 {
354 	struct dpll_device_registration *reg;
355 	bool first_registration = false;
356 
357 	if (WARN_ON(!ops))
358 		return -EINVAL;
359 	if (WARN_ON(!ops->mode_get))
360 		return -EINVAL;
361 	if (WARN_ON(!ops->lock_status_get))
362 		return -EINVAL;
363 	if (WARN_ON(type < DPLL_TYPE_PPS || type > DPLL_TYPE_MAX))
364 		return -EINVAL;
365 
366 	mutex_lock(&dpll_lock);
367 	reg = dpll_device_registration_find(dpll, ops, priv);
368 	if (reg) {
369 		mutex_unlock(&dpll_lock);
370 		return -EEXIST;
371 	}
372 
373 	reg = kzalloc(sizeof(*reg), GFP_KERNEL);
374 	if (!reg) {
375 		mutex_unlock(&dpll_lock);
376 		return -ENOMEM;
377 	}
378 	reg->ops = ops;
379 	reg->priv = priv;
380 	dpll->type = type;
381 	first_registration = list_empty(&dpll->registration_list);
382 	list_add_tail(&reg->list, &dpll->registration_list);
383 	if (!first_registration) {
384 		mutex_unlock(&dpll_lock);
385 		return 0;
386 	}
387 
388 	xa_set_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
389 	dpll_device_create_ntf(dpll);
390 	mutex_unlock(&dpll_lock);
391 
392 	return 0;
393 }
394 EXPORT_SYMBOL_GPL(dpll_device_register);
395 
396 /**
397  * dpll_device_unregister - unregister dpll device
398  * @dpll: registered dpll pointer
399  * @ops: ops for a dpll device
400  * @priv: pointer to private information of owner
401  *
402  * Unregister device, make it unavailable for userspace.
403  * Note: It does not free the memory
404  * Context: Acquires a lock (dpll_lock)
405  */
406 void dpll_device_unregister(struct dpll_device *dpll,
407 			    const struct dpll_device_ops *ops, void *priv)
408 {
409 	struct dpll_device_registration *reg;
410 
411 	mutex_lock(&dpll_lock);
412 	ASSERT_DPLL_REGISTERED(dpll);
413 	dpll_device_delete_ntf(dpll);
414 	reg = dpll_device_registration_find(dpll, ops, priv);
415 	if (WARN_ON(!reg)) {
416 		mutex_unlock(&dpll_lock);
417 		return;
418 	}
419 	list_del(&reg->list);
420 	kfree(reg);
421 
422 	if (!list_empty(&dpll->registration_list)) {
423 		mutex_unlock(&dpll_lock);
424 		return;
425 	}
426 	xa_clear_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
427 	mutex_unlock(&dpll_lock);
428 }
429 EXPORT_SYMBOL_GPL(dpll_device_unregister);
430 
431 static void dpll_pin_prop_free(struct dpll_pin_properties *prop)
432 {
433 	kfree(prop->package_label);
434 	kfree(prop->panel_label);
435 	kfree(prop->board_label);
436 	kfree(prop->freq_supported);
437 }
438 
439 static int dpll_pin_prop_dup(const struct dpll_pin_properties *src,
440 			     struct dpll_pin_properties *dst)
441 {
442 	memcpy(dst, src, sizeof(*dst));
443 	if (src->freq_supported && src->freq_supported_num) {
444 		size_t freq_size = src->freq_supported_num *
445 				   sizeof(*src->freq_supported);
446 		dst->freq_supported = kmemdup(src->freq_supported,
447 					      freq_size, GFP_KERNEL);
448 		if (!src->freq_supported)
449 			return -ENOMEM;
450 	}
451 	if (src->board_label) {
452 		dst->board_label = kstrdup(src->board_label, GFP_KERNEL);
453 		if (!dst->board_label)
454 			goto err_board_label;
455 	}
456 	if (src->panel_label) {
457 		dst->panel_label = kstrdup(src->panel_label, GFP_KERNEL);
458 		if (!dst->panel_label)
459 			goto err_panel_label;
460 	}
461 	if (src->package_label) {
462 		dst->package_label = kstrdup(src->package_label, GFP_KERNEL);
463 		if (!dst->package_label)
464 			goto err_package_label;
465 	}
466 
467 	return 0;
468 
469 err_package_label:
470 	kfree(dst->panel_label);
471 err_panel_label:
472 	kfree(dst->board_label);
473 err_board_label:
474 	kfree(dst->freq_supported);
475 	return -ENOMEM;
476 }
477 
478 static struct dpll_pin *
479 dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
480 	       const struct dpll_pin_properties *prop)
481 {
482 	struct dpll_pin *pin;
483 	int ret;
484 
485 	pin = kzalloc(sizeof(*pin), GFP_KERNEL);
486 	if (!pin)
487 		return ERR_PTR(-ENOMEM);
488 	pin->pin_idx = pin_idx;
489 	pin->clock_id = clock_id;
490 	pin->module = module;
491 	if (WARN_ON(prop->type < DPLL_PIN_TYPE_MUX ||
492 		    prop->type > DPLL_PIN_TYPE_MAX)) {
493 		ret = -EINVAL;
494 		goto err_pin_prop;
495 	}
496 	ret = dpll_pin_prop_dup(prop, &pin->prop);
497 	if (ret)
498 		goto err_pin_prop;
499 	refcount_set(&pin->refcount, 1);
500 	xa_init_flags(&pin->dpll_refs, XA_FLAGS_ALLOC);
501 	xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
502 	ret = xa_alloc_cyclic(&dpll_pin_xa, &pin->id, pin, xa_limit_32b,
503 			      &dpll_pin_xa_id, GFP_KERNEL);
504 	if (ret)
505 		goto err_xa_alloc;
506 	return pin;
507 err_xa_alloc:
508 	xa_destroy(&pin->dpll_refs);
509 	xa_destroy(&pin->parent_refs);
510 	dpll_pin_prop_free(&pin->prop);
511 err_pin_prop:
512 	kfree(pin);
513 	return ERR_PTR(ret);
514 }
515 
516 /**
517  * dpll_pin_get - find existing or create new dpll pin
518  * @clock_id: clock_id of creator
519  * @pin_idx: idx given by dev driver
520  * @module: reference to registering module
521  * @prop: dpll pin properties
522  *
523  * Get existing object of a pin (unique for given arguments) or create new
524  * if doesn't exist yet.
525  *
526  * Context: Acquires a lock (dpll_lock)
527  * Return:
528  * * valid allocated dpll_pin struct pointer if succeeded
529  * * ERR_PTR(X) - error
530  */
531 struct dpll_pin *
532 dpll_pin_get(u64 clock_id, u32 pin_idx, struct module *module,
533 	     const struct dpll_pin_properties *prop)
534 {
535 	struct dpll_pin *pos, *ret = NULL;
536 	unsigned long i;
537 
538 	mutex_lock(&dpll_lock);
539 	xa_for_each(&dpll_pin_xa, i, pos) {
540 		if (pos->clock_id == clock_id &&
541 		    pos->pin_idx == pin_idx &&
542 		    pos->module == module) {
543 			ret = pos;
544 			refcount_inc(&ret->refcount);
545 			break;
546 		}
547 	}
548 	if (!ret)
549 		ret = dpll_pin_alloc(clock_id, pin_idx, module, prop);
550 	mutex_unlock(&dpll_lock);
551 
552 	return ret;
553 }
554 EXPORT_SYMBOL_GPL(dpll_pin_get);
555 
556 /**
557  * dpll_pin_put - decrease the refcount and free memory if possible
558  * @pin: pointer to a pin to be put
559  *
560  * Drop reference for a pin, if all references are gone, delete pin object.
561  *
562  * Context: Acquires a lock (dpll_lock)
563  */
564 void dpll_pin_put(struct dpll_pin *pin)
565 {
566 	mutex_lock(&dpll_lock);
567 	if (refcount_dec_and_test(&pin->refcount)) {
568 		xa_destroy(&pin->dpll_refs);
569 		xa_destroy(&pin->parent_refs);
570 		xa_erase(&dpll_pin_xa, pin->id);
571 		dpll_pin_prop_free(&pin->prop);
572 		kfree_rcu(pin, rcu);
573 	}
574 	mutex_unlock(&dpll_lock);
575 }
576 EXPORT_SYMBOL_GPL(dpll_pin_put);
577 
578 static int
579 __dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
580 		    const struct dpll_pin_ops *ops, void *priv)
581 {
582 	int ret;
583 
584 	ret = dpll_xa_ref_pin_add(&dpll->pin_refs, pin, ops, priv);
585 	if (ret)
586 		return ret;
587 	ret = dpll_xa_ref_dpll_add(&pin->dpll_refs, dpll, ops, priv);
588 	if (ret)
589 		goto ref_pin_del;
590 	xa_set_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
591 	dpll_pin_create_ntf(pin);
592 
593 	return ret;
594 
595 ref_pin_del:
596 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
597 	return ret;
598 }
599 
600 /**
601  * dpll_pin_register - register the dpll pin in the subsystem
602  * @dpll: pointer to a dpll
603  * @pin: pointer to a dpll pin
604  * @ops: ops for a dpll pin ops
605  * @priv: pointer to private information of owner
606  *
607  * Context: Acquires a lock (dpll_lock)
608  * Return:
609  * * 0 on success
610  * * negative - error value
611  */
612 int
613 dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
614 		  const struct dpll_pin_ops *ops, void *priv)
615 {
616 	int ret;
617 
618 	if (WARN_ON(!ops) ||
619 	    WARN_ON(!ops->state_on_dpll_get) ||
620 	    WARN_ON(!ops->direction_get))
621 		return -EINVAL;
622 
623 	mutex_lock(&dpll_lock);
624 	if (WARN_ON(!(dpll->module == pin->module &&
625 		      dpll->clock_id == pin->clock_id)))
626 		ret = -EINVAL;
627 	else
628 		ret = __dpll_pin_register(dpll, pin, ops, priv);
629 	mutex_unlock(&dpll_lock);
630 
631 	return ret;
632 }
633 EXPORT_SYMBOL_GPL(dpll_pin_register);
634 
635 static void
636 __dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
637 		      const struct dpll_pin_ops *ops, void *priv)
638 {
639 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv);
640 	dpll_xa_ref_dpll_del(&pin->dpll_refs, dpll, ops, priv);
641 	if (xa_empty(&pin->dpll_refs))
642 		xa_clear_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
643 }
644 
645 /**
646  * dpll_pin_unregister - unregister dpll pin from dpll device
647  * @dpll: registered dpll pointer
648  * @pin: pointer to a pin
649  * @ops: ops for a dpll pin
650  * @priv: pointer to private information of owner
651  *
652  * Note: It does not free the memory
653  * Context: Acquires a lock (dpll_lock)
654  */
655 void dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
656 			 const struct dpll_pin_ops *ops, void *priv)
657 {
658 	if (WARN_ON(xa_empty(&dpll->pin_refs)))
659 		return;
660 	if (WARN_ON(!xa_empty(&pin->parent_refs)))
661 		return;
662 
663 	mutex_lock(&dpll_lock);
664 	dpll_pin_delete_ntf(pin);
665 	__dpll_pin_unregister(dpll, pin, ops, priv);
666 	mutex_unlock(&dpll_lock);
667 }
668 EXPORT_SYMBOL_GPL(dpll_pin_unregister);
669 
670 /**
671  * dpll_pin_on_pin_register - register a pin with a parent pin
672  * @parent: pointer to a parent pin
673  * @pin: pointer to a pin
674  * @ops: ops for a dpll pin
675  * @priv: pointer to private information of owner
676  *
677  * Register a pin with a parent pin, create references between them and
678  * between newly registered pin and dplls connected with a parent pin.
679  *
680  * Context: Acquires a lock (dpll_lock)
681  * Return:
682  * * 0 on success
683  * * negative - error value
684  */
685 int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
686 			     const struct dpll_pin_ops *ops, void *priv)
687 {
688 	struct dpll_pin_ref *ref;
689 	unsigned long i, stop;
690 	int ret;
691 
692 	if (WARN_ON(parent->prop.type != DPLL_PIN_TYPE_MUX))
693 		return -EINVAL;
694 
695 	if (WARN_ON(!ops) ||
696 	    WARN_ON(!ops->state_on_pin_get) ||
697 	    WARN_ON(!ops->direction_get))
698 		return -EINVAL;
699 
700 	mutex_lock(&dpll_lock);
701 	ret = dpll_xa_ref_pin_add(&pin->parent_refs, parent, ops, priv);
702 	if (ret)
703 		goto unlock;
704 	refcount_inc(&pin->refcount);
705 	xa_for_each(&parent->dpll_refs, i, ref) {
706 		ret = __dpll_pin_register(ref->dpll, pin, ops, priv);
707 		if (ret) {
708 			stop = i;
709 			goto dpll_unregister;
710 		}
711 		dpll_pin_create_ntf(pin);
712 	}
713 	mutex_unlock(&dpll_lock);
714 
715 	return ret;
716 
717 dpll_unregister:
718 	xa_for_each(&parent->dpll_refs, i, ref)
719 		if (i < stop) {
720 			__dpll_pin_unregister(ref->dpll, pin, ops, priv);
721 			dpll_pin_delete_ntf(pin);
722 		}
723 	refcount_dec(&pin->refcount);
724 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
725 unlock:
726 	mutex_unlock(&dpll_lock);
727 	return ret;
728 }
729 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_register);
730 
731 /**
732  * dpll_pin_on_pin_unregister - unregister dpll pin from a parent pin
733  * @parent: pointer to a parent pin
734  * @pin: pointer to a pin
735  * @ops: ops for a dpll pin
736  * @priv: pointer to private information of owner
737  *
738  * Context: Acquires a lock (dpll_lock)
739  * Note: It does not free the memory
740  */
741 void dpll_pin_on_pin_unregister(struct dpll_pin *parent, struct dpll_pin *pin,
742 				const struct dpll_pin_ops *ops, void *priv)
743 {
744 	struct dpll_pin_ref *ref;
745 	unsigned long i;
746 
747 	mutex_lock(&dpll_lock);
748 	dpll_pin_delete_ntf(pin);
749 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv);
750 	refcount_dec(&pin->refcount);
751 	xa_for_each(&pin->dpll_refs, i, ref)
752 		__dpll_pin_unregister(ref->dpll, pin, ops, priv);
753 	mutex_unlock(&dpll_lock);
754 }
755 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_unregister);
756 
757 static struct dpll_device_registration *
758 dpll_device_registration_first(struct dpll_device *dpll)
759 {
760 	struct dpll_device_registration *reg;
761 
762 	reg = list_first_entry_or_null((struct list_head *)&dpll->registration_list,
763 				       struct dpll_device_registration, list);
764 	WARN_ON(!reg);
765 	return reg;
766 }
767 
768 void *dpll_priv(struct dpll_device *dpll)
769 {
770 	struct dpll_device_registration *reg;
771 
772 	reg = dpll_device_registration_first(dpll);
773 	return reg->priv;
774 }
775 
776 const struct dpll_device_ops *dpll_device_ops(struct dpll_device *dpll)
777 {
778 	struct dpll_device_registration *reg;
779 
780 	reg = dpll_device_registration_first(dpll);
781 	return reg->ops;
782 }
783 
784 static struct dpll_pin_registration *
785 dpll_pin_registration_first(struct dpll_pin_ref *ref)
786 {
787 	struct dpll_pin_registration *reg;
788 
789 	reg = list_first_entry_or_null(&ref->registration_list,
790 				       struct dpll_pin_registration, list);
791 	WARN_ON(!reg);
792 	return reg;
793 }
794 
795 void *dpll_pin_on_dpll_priv(struct dpll_device *dpll,
796 			    struct dpll_pin *pin)
797 {
798 	struct dpll_pin_registration *reg;
799 	struct dpll_pin_ref *ref;
800 
801 	ref = xa_load(&dpll->pin_refs, pin->pin_idx);
802 	if (!ref)
803 		return NULL;
804 	reg = dpll_pin_registration_first(ref);
805 	return reg->priv;
806 }
807 
808 void *dpll_pin_on_pin_priv(struct dpll_pin *parent,
809 			   struct dpll_pin *pin)
810 {
811 	struct dpll_pin_registration *reg;
812 	struct dpll_pin_ref *ref;
813 
814 	ref = xa_load(&pin->parent_refs, parent->pin_idx);
815 	if (!ref)
816 		return NULL;
817 	reg = dpll_pin_registration_first(ref);
818 	return reg->priv;
819 }
820 
821 const struct dpll_pin_ops *dpll_pin_ops(struct dpll_pin_ref *ref)
822 {
823 	struct dpll_pin_registration *reg;
824 
825 	reg = dpll_pin_registration_first(ref);
826 	return reg->ops;
827 }
828 
829 static int __init dpll_init(void)
830 {
831 	int ret;
832 
833 	ret = genl_register_family(&dpll_nl_family);
834 	if (ret)
835 		goto error;
836 
837 	return 0;
838 
839 error:
840 	mutex_destroy(&dpll_lock);
841 	return ret;
842 }
843 
844 static void __exit dpll_exit(void)
845 {
846 	genl_unregister_family(&dpll_nl_family);
847 	mutex_destroy(&dpll_lock);
848 }
849 
850 subsys_initcall(dpll_init);
851 module_exit(dpll_exit);
852