xref: /linux/drivers/dpll/dpll_core.c (revision 32239d600236a986c8e6d16aa814d3d91066b244)
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/idr.h>
14 #include <linux/module.h>
15 #include <linux/property.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 
19 #include "dpll_core.h"
20 #include "dpll_netlink.h"
21 
22 /* Mutex lock to protect DPLL subsystem devices and pins */
23 DEFINE_MUTEX(dpll_lock);
24 
25 DEFINE_XARRAY_FLAGS(dpll_device_xa, XA_FLAGS_ALLOC);
26 DEFINE_XARRAY_FLAGS(dpll_pin_xa, XA_FLAGS_ALLOC);
27 
28 static RAW_NOTIFIER_HEAD(dpll_notifier_chain);
29 static DEFINE_IDA(dpll_pin_idx_ida);
30 
31 static u32 dpll_device_xa_id;
32 static u32 dpll_pin_xa_id;
33 
34 #define ASSERT_DPLL_REGISTERED(d)	\
35 	WARN_ON_ONCE(!xa_get_mark(&dpll_device_xa, (d)->id, DPLL_REGISTERED))
36 #define ASSERT_DPLL_NOT_REGISTERED(d)	\
37 	WARN_ON_ONCE(xa_get_mark(&dpll_device_xa, (d)->id, DPLL_REGISTERED))
38 #define ASSERT_DPLL_PIN_REGISTERED(p) \
39 	WARN_ON_ONCE(!xa_get_mark(&dpll_pin_xa, (p)->id, DPLL_REGISTERED))
40 
41 struct dpll_device_registration {
42 	struct list_head list;
43 	const struct dpll_device_ops *ops;
44 	void *priv;
45 	dpll_tracker tracker;
46 };
47 
48 struct dpll_pin_registration {
49 	struct list_head list;
50 	const struct dpll_pin_ops *ops;
51 	void *priv;
52 	void *cookie;
53 	dpll_tracker tracker;
54 };
55 
56 static int call_dpll_notifiers(unsigned long action, void *info)
57 {
58 	lockdep_assert_held(&dpll_lock);
59 	return raw_notifier_call_chain(&dpll_notifier_chain, action, info);
60 }
61 
62 void dpll_device_notify(struct dpll_device *dpll, unsigned long action)
63 {
64 	struct dpll_device_notifier_info info = {
65 		.dpll = dpll,
66 		.id = dpll->id,
67 		.idx = dpll->device_idx,
68 		.clock_id = dpll->clock_id,
69 		.type = dpll->type,
70 	};
71 
72 	call_dpll_notifiers(action, &info);
73 }
74 
75 void dpll_pin_notify(struct dpll_pin *pin, unsigned long action)
76 {
77 	struct dpll_pin_notifier_info info = {
78 		.pin = pin,
79 		.id = pin->id,
80 		.idx = pin->pin_idx,
81 		.clock_id = pin->clock_id,
82 		.fwnode = pin->fwnode,
83 		.prop = &pin->prop,
84 	};
85 
86 	call_dpll_notifiers(action, &info);
87 }
88 
89 static void dpll_device_tracker_alloc(struct dpll_device *dpll,
90 				      dpll_tracker *tracker)
91 {
92 #ifdef CONFIG_DPLL_REFCNT_TRACKER
93 	ref_tracker_alloc(&dpll->refcnt_tracker, tracker, GFP_KERNEL);
94 #endif
95 }
96 
97 static void dpll_device_tracker_free(struct dpll_device *dpll,
98 				     dpll_tracker *tracker)
99 {
100 #ifdef CONFIG_DPLL_REFCNT_TRACKER
101 	ref_tracker_free(&dpll->refcnt_tracker, tracker);
102 #endif
103 }
104 
105 static void __dpll_device_hold(struct dpll_device *dpll, dpll_tracker *tracker)
106 {
107 	dpll_device_tracker_alloc(dpll, tracker);
108 	refcount_inc(&dpll->refcount);
109 }
110 
111 static void __dpll_device_put(struct dpll_device *dpll, dpll_tracker *tracker)
112 {
113 	dpll_device_tracker_free(dpll, tracker);
114 	if (refcount_dec_and_test(&dpll->refcount)) {
115 		ASSERT_DPLL_NOT_REGISTERED(dpll);
116 		WARN_ON_ONCE(!xa_empty(&dpll->pin_refs));
117 		xa_destroy(&dpll->pin_refs);
118 		xa_erase(&dpll_device_xa, dpll->id);
119 		WARN_ON(!list_empty(&dpll->registration_list));
120 		ref_tracker_dir_exit(&dpll->refcnt_tracker);
121 		kfree(dpll);
122 	}
123 }
124 
125 static void dpll_pin_tracker_alloc(struct dpll_pin *pin, dpll_tracker *tracker)
126 {
127 #ifdef CONFIG_DPLL_REFCNT_TRACKER
128 	ref_tracker_alloc(&pin->refcnt_tracker, tracker, GFP_KERNEL);
129 #endif
130 }
131 
132 static void dpll_pin_tracker_free(struct dpll_pin *pin, dpll_tracker *tracker)
133 {
134 #ifdef CONFIG_DPLL_REFCNT_TRACKER
135 	ref_tracker_free(&pin->refcnt_tracker, tracker);
136 #endif
137 }
138 
139 static void __dpll_pin_hold(struct dpll_pin *pin, dpll_tracker *tracker)
140 {
141 	dpll_pin_tracker_alloc(pin, tracker);
142 	refcount_inc(&pin->refcount);
143 }
144 
145 static void dpll_pin_idx_free(u32 pin_idx);
146 static void dpll_pin_prop_free(struct dpll_pin_properties *prop);
147 
148 static void __dpll_pin_put(struct dpll_pin *pin, dpll_tracker *tracker)
149 {
150 	dpll_pin_tracker_free(pin, tracker);
151 	if (refcount_dec_and_test(&pin->refcount)) {
152 		xa_erase(&dpll_pin_xa, pin->id);
153 		xa_destroy(&pin->dpll_refs);
154 		xa_destroy(&pin->parent_refs);
155 		xa_destroy(&pin->ref_sync_pins);
156 		dpll_pin_prop_free(&pin->prop);
157 		fwnode_handle_put(pin->fwnode);
158 		dpll_pin_idx_free(pin->pin_idx);
159 		ref_tracker_dir_exit(&pin->refcnt_tracker);
160 		kfree_rcu(pin, rcu);
161 	}
162 }
163 
164 struct dpll_device *dpll_device_get_by_id(int id)
165 {
166 	if (xa_get_mark(&dpll_device_xa, id, DPLL_REGISTERED))
167 		return xa_load(&dpll_device_xa, id);
168 
169 	return NULL;
170 }
171 
172 static struct dpll_pin_registration *
173 dpll_pin_registration_find(struct dpll_pin_ref *ref,
174 			   const struct dpll_pin_ops *ops, void *priv,
175 			   void *cookie)
176 {
177 	struct dpll_pin_registration *reg;
178 
179 	list_for_each_entry(reg, &ref->registration_list, list) {
180 		if (reg->ops == ops && reg->priv == priv &&
181 		    reg->cookie == cookie)
182 			return reg;
183 	}
184 	return NULL;
185 }
186 
187 static int
188 dpll_xa_ref_pin_add(struct xarray *xa_pins, struct dpll_pin *pin,
189 		    const struct dpll_pin_ops *ops, void *priv,
190 		    void *cookie)
191 {
192 	struct dpll_pin_registration *reg;
193 	struct dpll_pin_ref *ref;
194 	bool ref_exists = false;
195 	unsigned long i;
196 	int ret;
197 
198 	xa_for_each(xa_pins, i, ref) {
199 		if (ref->pin != pin)
200 			continue;
201 		reg = dpll_pin_registration_find(ref, ops, priv, cookie);
202 		if (reg)
203 			return -EEXIST;
204 		ref_exists = true;
205 		break;
206 	}
207 
208 	if (!ref_exists) {
209 		ref = kzalloc_obj(*ref);
210 		if (!ref)
211 			return -ENOMEM;
212 		ref->pin = pin;
213 		INIT_LIST_HEAD(&ref->registration_list);
214 		ret = xa_insert(xa_pins, pin->pin_idx, ref, GFP_KERNEL);
215 		if (ret) {
216 			kfree(ref);
217 			return ret;
218 		}
219 		refcount_set(&ref->refcount, 1);
220 	}
221 
222 	reg = kzalloc_obj(*reg);
223 	if (!reg) {
224 		if (!ref_exists) {
225 			xa_erase(xa_pins, pin->pin_idx);
226 			kfree(ref);
227 		}
228 		return -ENOMEM;
229 	}
230 	reg->ops = ops;
231 	reg->priv = priv;
232 	reg->cookie = cookie;
233 	__dpll_pin_hold(pin, &reg->tracker);
234 	if (ref_exists)
235 		refcount_inc(&ref->refcount);
236 	list_add_tail(&reg->list, &ref->registration_list);
237 
238 	return 0;
239 }
240 
241 static int dpll_xa_ref_pin_del(struct xarray *xa_pins, struct dpll_pin *pin,
242 			       const struct dpll_pin_ops *ops, void *priv,
243 			       void *cookie)
244 {
245 	struct dpll_pin_registration *reg;
246 	struct dpll_pin_ref *ref;
247 	unsigned long i;
248 
249 	xa_for_each(xa_pins, i, ref) {
250 		if (ref->pin != pin)
251 			continue;
252 		reg = dpll_pin_registration_find(ref, ops, priv, cookie);
253 		if (WARN_ON(!reg))
254 			return -EINVAL;
255 		list_del(&reg->list);
256 		__dpll_pin_put(pin, &reg->tracker);
257 		kfree(reg);
258 		if (refcount_dec_and_test(&ref->refcount)) {
259 			xa_erase(xa_pins, i);
260 			WARN_ON(!list_empty(&ref->registration_list));
261 			kfree(ref);
262 		}
263 		return 0;
264 	}
265 
266 	return -EINVAL;
267 }
268 
269 static int
270 dpll_xa_ref_dpll_add(struct xarray *xa_dplls, struct dpll_device *dpll,
271 		     const struct dpll_pin_ops *ops, void *priv, void *cookie)
272 {
273 	struct dpll_pin_registration *reg;
274 	struct dpll_pin_ref *ref;
275 	bool ref_exists = false;
276 	unsigned long i;
277 	int ret;
278 
279 	xa_for_each(xa_dplls, i, ref) {
280 		if (ref->dpll != dpll)
281 			continue;
282 		reg = dpll_pin_registration_find(ref, ops, priv, cookie);
283 		if (reg)
284 			return -EEXIST;
285 		ref_exists = true;
286 		break;
287 	}
288 
289 	if (!ref_exists) {
290 		ref = kzalloc_obj(*ref);
291 		if (!ref)
292 			return -ENOMEM;
293 		ref->dpll = dpll;
294 		INIT_LIST_HEAD(&ref->registration_list);
295 		ret = xa_insert(xa_dplls, dpll->id, ref, GFP_KERNEL);
296 		if (ret) {
297 			kfree(ref);
298 			return ret;
299 		}
300 		refcount_set(&ref->refcount, 1);
301 	}
302 
303 	reg = kzalloc_obj(*reg);
304 	if (!reg) {
305 		if (!ref_exists) {
306 			xa_erase(xa_dplls, dpll->id);
307 			kfree(ref);
308 		}
309 		return -ENOMEM;
310 	}
311 	reg->ops = ops;
312 	reg->priv = priv;
313 	reg->cookie = cookie;
314 	__dpll_device_hold(dpll, &reg->tracker);
315 	if (ref_exists)
316 		refcount_inc(&ref->refcount);
317 	list_add_tail(&reg->list, &ref->registration_list);
318 
319 	return 0;
320 }
321 
322 static void
323 dpll_xa_ref_dpll_del(struct xarray *xa_dplls, struct dpll_device *dpll,
324 		     const struct dpll_pin_ops *ops, void *priv, void *cookie)
325 {
326 	struct dpll_pin_registration *reg;
327 	struct dpll_pin_ref *ref;
328 	unsigned long i;
329 
330 	xa_for_each(xa_dplls, i, ref) {
331 		if (ref->dpll != dpll)
332 			continue;
333 		reg = dpll_pin_registration_find(ref, ops, priv, cookie);
334 		if (WARN_ON(!reg))
335 			return;
336 		list_del(&reg->list);
337 		__dpll_device_put(dpll, &reg->tracker);
338 		kfree(reg);
339 		if (refcount_dec_and_test(&ref->refcount)) {
340 			xa_erase(xa_dplls, i);
341 			WARN_ON(!list_empty(&ref->registration_list));
342 			kfree(ref);
343 		}
344 		return;
345 	}
346 }
347 
348 struct dpll_pin_ref *dpll_xa_ref_dpll_first(struct xarray *xa_refs)
349 {
350 	struct dpll_pin_ref *ref;
351 	unsigned long i = 0;
352 
353 	ref = xa_find(xa_refs, &i, ULONG_MAX, XA_PRESENT);
354 	WARN_ON(!ref);
355 	return ref;
356 }
357 
358 static struct dpll_device *
359 dpll_device_alloc(const u64 clock_id, u32 device_idx, struct module *module)
360 {
361 	struct dpll_device *dpll;
362 	int ret;
363 
364 	dpll = kzalloc_obj(*dpll);
365 	if (!dpll)
366 		return ERR_PTR(-ENOMEM);
367 	refcount_set(&dpll->refcount, 1);
368 	INIT_LIST_HEAD(&dpll->registration_list);
369 	dpll->device_idx = device_idx;
370 	dpll->clock_id = clock_id;
371 	dpll->module = module;
372 	ret = xa_alloc_cyclic(&dpll_device_xa, &dpll->id, dpll, xa_limit_32b,
373 			      &dpll_device_xa_id, GFP_KERNEL);
374 	if (ret < 0) {
375 		kfree(dpll);
376 		return ERR_PTR(ret);
377 	}
378 	xa_init_flags(&dpll->pin_refs, XA_FLAGS_ALLOC);
379 	ref_tracker_dir_init(&dpll->refcnt_tracker, 128, "dpll_device");
380 
381 	return dpll;
382 }
383 
384 /**
385  * dpll_device_get - find existing or create new dpll device
386  * @clock_id: clock_id of creator
387  * @device_idx: idx given by device driver
388  * @module: reference to registering module
389  * @tracker: tracking object for the acquired reference
390  *
391  * Get existing object of a dpll device, unique for given arguments.
392  * Create new if doesn't exist yet.
393  *
394  * Context: Acquires a lock (dpll_lock)
395  * Return:
396  * * valid dpll_device struct pointer if succeeded
397  * * ERR_PTR(X) - error
398  */
399 struct dpll_device *
400 dpll_device_get(u64 clock_id, u32 device_idx, struct module *module,
401 		dpll_tracker *tracker)
402 {
403 	struct dpll_device *dpll, *ret = NULL;
404 	unsigned long index;
405 
406 	mutex_lock(&dpll_lock);
407 	xa_for_each(&dpll_device_xa, index, dpll) {
408 		if (dpll->clock_id == clock_id &&
409 		    dpll->device_idx == device_idx &&
410 		    dpll->module == module) {
411 			__dpll_device_hold(dpll, tracker);
412 			ret = dpll;
413 			break;
414 		}
415 	}
416 	if (!ret) {
417 		ret = dpll_device_alloc(clock_id, device_idx, module);
418 		if (!IS_ERR(ret))
419 			dpll_device_tracker_alloc(ret, tracker);
420 	}
421 
422 	mutex_unlock(&dpll_lock);
423 
424 	return ret;
425 }
426 EXPORT_SYMBOL_GPL(dpll_device_get);
427 
428 /**
429  * dpll_device_put - decrease the refcount and free memory if possible
430  * @dpll: dpll_device struct pointer
431  * @tracker: tracking object for the acquired reference
432  *
433  * Context: Acquires a lock (dpll_lock)
434  * Drop reference for a dpll device, if all references are gone, delete
435  * dpll device object.
436  */
437 void dpll_device_put(struct dpll_device *dpll, dpll_tracker *tracker)
438 {
439 	mutex_lock(&dpll_lock);
440 	__dpll_device_put(dpll, tracker);
441 	mutex_unlock(&dpll_lock);
442 }
443 EXPORT_SYMBOL_GPL(dpll_device_put);
444 
445 static struct dpll_device_registration *
446 dpll_device_registration_find(struct dpll_device *dpll,
447 			      const struct dpll_device_ops *ops, void *priv)
448 {
449 	struct dpll_device_registration *reg;
450 
451 	list_for_each_entry(reg, &dpll->registration_list, list) {
452 		if (reg->ops == ops && reg->priv == priv)
453 			return reg;
454 	}
455 	return NULL;
456 }
457 
458 /**
459  * dpll_device_register - register the dpll device in the subsystem
460  * @dpll: pointer to a dpll
461  * @type: type of a dpll
462  * @ops: ops for a dpll device
463  * @priv: pointer to private information of owner
464  *
465  * Make dpll device available for user space.
466  *
467  * Context: Acquires a lock (dpll_lock)
468  * Return:
469  * * 0 on success
470  * * negative - error value
471  */
472 int dpll_device_register(struct dpll_device *dpll, enum dpll_type type,
473 			 const struct dpll_device_ops *ops, void *priv)
474 {
475 	struct dpll_device_registration *reg;
476 	bool first_registration = false;
477 
478 	if (WARN_ON(!ops))
479 		return -EINVAL;
480 	if (WARN_ON(!ops->mode_get))
481 		return -EINVAL;
482 	if (WARN_ON(!ops->lock_status_get))
483 		return -EINVAL;
484 	if (WARN_ON(type < DPLL_TYPE_PPS || type > DPLL_TYPE_MAX))
485 		return -EINVAL;
486 
487 	mutex_lock(&dpll_lock);
488 	reg = dpll_device_registration_find(dpll, ops, priv);
489 	if (reg) {
490 		mutex_unlock(&dpll_lock);
491 		return -EEXIST;
492 	}
493 
494 	reg = kzalloc_obj(*reg);
495 	if (!reg) {
496 		mutex_unlock(&dpll_lock);
497 		return -ENOMEM;
498 	}
499 	reg->ops = ops;
500 	reg->priv = priv;
501 	dpll->type = type;
502 	__dpll_device_hold(dpll, &reg->tracker);
503 	first_registration = list_empty(&dpll->registration_list);
504 	list_add_tail(&reg->list, &dpll->registration_list);
505 	if (!first_registration) {
506 		mutex_unlock(&dpll_lock);
507 		return 0;
508 	}
509 
510 	xa_set_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
511 	dpll_device_create_ntf(dpll);
512 	mutex_unlock(&dpll_lock);
513 
514 	return 0;
515 }
516 EXPORT_SYMBOL_GPL(dpll_device_register);
517 
518 /**
519  * dpll_device_unregister - unregister dpll device
520  * @dpll: registered dpll pointer
521  * @ops: ops for a dpll device
522  * @priv: pointer to private information of owner
523  *
524  * Unregister device, make it unavailable for userspace.
525  * Note: It does not free the memory
526  * Context: Acquires a lock (dpll_lock)
527  */
528 void dpll_device_unregister(struct dpll_device *dpll,
529 			    const struct dpll_device_ops *ops, void *priv)
530 {
531 	struct dpll_device_registration *reg;
532 
533 	mutex_lock(&dpll_lock);
534 	ASSERT_DPLL_REGISTERED(dpll);
535 	dpll_device_delete_ntf(dpll);
536 	reg = dpll_device_registration_find(dpll, ops, priv);
537 	if (WARN_ON(!reg)) {
538 		mutex_unlock(&dpll_lock);
539 		return;
540 	}
541 	list_del(&reg->list);
542 	__dpll_device_put(dpll, &reg->tracker);
543 	kfree(reg);
544 
545 	if (!list_empty(&dpll->registration_list)) {
546 		mutex_unlock(&dpll_lock);
547 		return;
548 	}
549 	xa_clear_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
550 	mutex_unlock(&dpll_lock);
551 }
552 EXPORT_SYMBOL_GPL(dpll_device_unregister);
553 
554 static int dpll_pin_idx_alloc(u32 *pin_idx)
555 {
556 	int ret;
557 
558 	if (!pin_idx)
559 		return -EINVAL;
560 
561 	/* Alloc unique number from IDA. Number belongs to <0, INT_MAX> range */
562 	ret = ida_alloc(&dpll_pin_idx_ida, GFP_KERNEL);
563 	if (ret < 0)
564 		return ret;
565 
566 	/* Map the value to dynamic pin index range <INT_MAX+1, U32_MAX> */
567 	*pin_idx = (u32)ret + INT_MAX + 1;
568 
569 	return 0;
570 }
571 
572 static void dpll_pin_idx_free(u32 pin_idx)
573 {
574 	if (pin_idx <= INT_MAX)
575 		return; /* Not a dynamic pin index */
576 
577 	/* Map the index value from dynamic pin index range to IDA range and
578 	 * free it.
579 	 */
580 	pin_idx -= (u32)INT_MAX + 1;
581 	ida_free(&dpll_pin_idx_ida, pin_idx);
582 }
583 
584 static void dpll_pin_prop_free(struct dpll_pin_properties *prop)
585 {
586 	kfree(prop->package_label);
587 	kfree(prop->panel_label);
588 	kfree(prop->board_label);
589 	kfree(prop->freq_supported);
590 }
591 
592 static int dpll_pin_prop_dup(const struct dpll_pin_properties *src,
593 			     struct dpll_pin_properties *dst)
594 {
595 	if (WARN_ON(src->freq_supported && !src->freq_supported_num))
596 		return -EINVAL;
597 
598 	memcpy(dst, src, sizeof(*dst));
599 	if (src->freq_supported) {
600 		size_t freq_size = src->freq_supported_num *
601 				   sizeof(*src->freq_supported);
602 		dst->freq_supported = kmemdup(src->freq_supported,
603 					      freq_size, GFP_KERNEL);
604 		if (!dst->freq_supported)
605 			return -ENOMEM;
606 	}
607 	if (src->board_label) {
608 		dst->board_label = kstrdup(src->board_label, GFP_KERNEL);
609 		if (!dst->board_label)
610 			goto err_board_label;
611 	}
612 	if (src->panel_label) {
613 		dst->panel_label = kstrdup(src->panel_label, GFP_KERNEL);
614 		if (!dst->panel_label)
615 			goto err_panel_label;
616 	}
617 	if (src->package_label) {
618 		dst->package_label = kstrdup(src->package_label, GFP_KERNEL);
619 		if (!dst->package_label)
620 			goto err_package_label;
621 	}
622 
623 	return 0;
624 
625 err_package_label:
626 	kfree(dst->panel_label);
627 err_panel_label:
628 	kfree(dst->board_label);
629 err_board_label:
630 	kfree(dst->freq_supported);
631 	return -ENOMEM;
632 }
633 
634 static struct dpll_pin *
635 dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
636 	       const struct dpll_pin_properties *prop)
637 {
638 	struct dpll_pin *pin;
639 	int ret;
640 
641 	if (pin_idx == DPLL_PIN_IDX_UNSPEC) {
642 		ret = dpll_pin_idx_alloc(&pin_idx);
643 		if (ret)
644 			return ERR_PTR(ret);
645 	} else if (pin_idx > INT_MAX) {
646 		return ERR_PTR(-EINVAL);
647 	}
648 	pin = kzalloc_obj(*pin);
649 	if (!pin) {
650 		ret = -ENOMEM;
651 		goto err_pin_alloc;
652 	}
653 	pin->pin_idx = pin_idx;
654 	pin->clock_id = clock_id;
655 	pin->module = module;
656 	strscpy(pin->module_name, module_name(module));
657 	if (WARN_ON(prop->type < DPLL_PIN_TYPE_MUX ||
658 		    prop->type > DPLL_PIN_TYPE_MAX)) {
659 		ret = -EINVAL;
660 		goto err_pin_prop;
661 	}
662 	ret = dpll_pin_prop_dup(prop, &pin->prop);
663 	if (ret)
664 		goto err_pin_prop;
665 	refcount_set(&pin->refcount, 1);
666 	xa_init_flags(&pin->dpll_refs, XA_FLAGS_ALLOC);
667 	xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
668 	xa_init_flags(&pin->ref_sync_pins, XA_FLAGS_ALLOC);
669 	ret = xa_alloc_cyclic(&dpll_pin_xa, &pin->id, pin, xa_limit_32b,
670 			      &dpll_pin_xa_id, GFP_KERNEL);
671 	if (ret < 0)
672 		goto err_xa_alloc;
673 	ref_tracker_dir_init(&pin->refcnt_tracker, 128, "dpll_pin");
674 	return pin;
675 err_xa_alloc:
676 	xa_destroy(&pin->dpll_refs);
677 	xa_destroy(&pin->parent_refs);
678 	xa_destroy(&pin->ref_sync_pins);
679 	dpll_pin_prop_free(&pin->prop);
680 err_pin_prop:
681 	kfree(pin);
682 err_pin_alloc:
683 	dpll_pin_idx_free(pin_idx);
684 	return ERR_PTR(ret);
685 }
686 
687 static void dpll_netdev_pin_assign(struct net_device *dev, struct dpll_pin *dpll_pin)
688 {
689 	rtnl_lock();
690 	rcu_assign_pointer(dev->dpll_pin, dpll_pin);
691 	rtnl_unlock();
692 }
693 
694 void dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)
695 {
696 	WARN_ON(!dpll_pin);
697 	dpll_netdev_pin_assign(dev, dpll_pin);
698 }
699 EXPORT_SYMBOL(dpll_netdev_pin_set);
700 
701 void dpll_netdev_pin_clear(struct net_device *dev)
702 {
703 	dpll_netdev_pin_assign(dev, NULL);
704 }
705 EXPORT_SYMBOL(dpll_netdev_pin_clear);
706 
707 int register_dpll_notifier(struct notifier_block *nb)
708 {
709 	int ret;
710 
711 	mutex_lock(&dpll_lock);
712 	ret = raw_notifier_chain_register(&dpll_notifier_chain, nb);
713 	mutex_unlock(&dpll_lock);
714 	return ret;
715 }
716 EXPORT_SYMBOL_GPL(register_dpll_notifier);
717 
718 int unregister_dpll_notifier(struct notifier_block *nb)
719 {
720 	int ret;
721 
722 	mutex_lock(&dpll_lock);
723 	ret = raw_notifier_chain_unregister(&dpll_notifier_chain, nb);
724 	mutex_unlock(&dpll_lock);
725 	return ret;
726 }
727 EXPORT_SYMBOL_GPL(unregister_dpll_notifier);
728 
729 /**
730  * dpll_pin_get - find existing or create new dpll pin
731  * @clock_id: clock_id of creator
732  * @pin_idx: idx given by dev driver
733  * @module: reference to registering module
734  * @prop: dpll pin properties
735  * @tracker: tracking object for the acquired reference
736  *
737  * Get existing object of a pin (unique for given arguments) or create new
738  * if doesn't exist yet.
739  *
740  * Context: Acquires a lock (dpll_lock)
741  * Return:
742  * * valid allocated dpll_pin struct pointer if succeeded
743  * * ERR_PTR(X) - error
744  */
745 struct dpll_pin *
746 dpll_pin_get(u64 clock_id, u32 pin_idx, struct module *module,
747 	     const struct dpll_pin_properties *prop, dpll_tracker *tracker)
748 {
749 	struct dpll_pin *pos, *ret = NULL;
750 	unsigned long i;
751 
752 	mutex_lock(&dpll_lock);
753 	xa_for_each(&dpll_pin_xa, i, pos) {
754 		if (pos->clock_id == clock_id &&
755 		    pos->pin_idx == pin_idx &&
756 		    pos->module == module) {
757 			__dpll_pin_hold(pos, tracker);
758 			ret = pos;
759 			break;
760 		}
761 	}
762 	if (!ret) {
763 		ret = dpll_pin_alloc(clock_id, pin_idx, module, prop);
764 		if (!IS_ERR(ret))
765 			dpll_pin_tracker_alloc(ret, tracker);
766 	}
767 	mutex_unlock(&dpll_lock);
768 
769 	return ret;
770 }
771 EXPORT_SYMBOL_GPL(dpll_pin_get);
772 
773 /**
774  * dpll_pin_put - decrease the refcount and free memory if possible
775  * @pin: pointer to a pin to be put
776  * @tracker: tracking object for the acquired reference
777  *
778  * Drop reference for a pin, if all references are gone, delete pin object.
779  *
780  * Context: Acquires a lock (dpll_lock)
781  */
782 void dpll_pin_put(struct dpll_pin *pin, dpll_tracker *tracker)
783 {
784 	mutex_lock(&dpll_lock);
785 	__dpll_pin_put(pin, tracker);
786 	mutex_unlock(&dpll_lock);
787 }
788 EXPORT_SYMBOL_GPL(dpll_pin_put);
789 
790 /**
791  * dpll_pin_fwnode_set - set dpll pin firmware node reference
792  * @pin: pointer to a dpll pin
793  * @fwnode: firmware node handle
794  *
795  * Set firmware node handle for the given dpll pin.
796  */
797 void dpll_pin_fwnode_set(struct dpll_pin *pin, struct fwnode_handle *fwnode)
798 {
799 	mutex_lock(&dpll_lock);
800 	fwnode_handle_put(pin->fwnode); /* Drop fwnode previously set */
801 	pin->fwnode = fwnode_handle_get(fwnode);
802 	mutex_unlock(&dpll_lock);
803 }
804 EXPORT_SYMBOL_GPL(dpll_pin_fwnode_set);
805 
806 /**
807  * fwnode_dpll_pin_find - find dpll pin by firmware node reference
808  * @fwnode: reference to firmware node
809  * @tracker: tracking object for the acquired reference
810  *
811  * Get existing object of a pin that is associated with given firmware node
812  * reference.
813  *
814  * Context: Acquires a lock (dpll_lock)
815  * Return:
816  * * valid dpll_pin pointer on success
817  * * NULL when no such pin exists
818  */
819 struct dpll_pin *fwnode_dpll_pin_find(struct fwnode_handle *fwnode,
820 				      dpll_tracker *tracker)
821 {
822 	struct dpll_pin *pin, *ret = NULL;
823 	unsigned long index;
824 
825 	mutex_lock(&dpll_lock);
826 	xa_for_each(&dpll_pin_xa, index, pin) {
827 		if (pin->fwnode == fwnode) {
828 			__dpll_pin_hold(pin, tracker);
829 			ret = pin;
830 			break;
831 		}
832 	}
833 	mutex_unlock(&dpll_lock);
834 
835 	return ret;
836 }
837 EXPORT_SYMBOL_GPL(fwnode_dpll_pin_find);
838 
839 static int
840 __dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
841 		    const struct dpll_pin_ops *ops, void *priv, void *cookie)
842 {
843 	int ret;
844 
845 	ret = dpll_xa_ref_pin_add(&dpll->pin_refs, pin, ops, priv, cookie);
846 	if (ret)
847 		return ret;
848 	ret = dpll_xa_ref_dpll_add(&pin->dpll_refs, dpll, ops, priv, cookie);
849 	if (ret)
850 		goto ref_pin_del;
851 	xa_set_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
852 	dpll_pin_create_ntf(pin);
853 
854 	return ret;
855 
856 ref_pin_del:
857 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv, cookie);
858 	return ret;
859 }
860 
861 /**
862  * dpll_pin_register - register the dpll pin in the subsystem
863  * @dpll: pointer to a dpll
864  * @pin: pointer to a dpll pin
865  * @ops: ops for a dpll pin ops
866  * @priv: pointer to private information of owner
867  *
868  * Context: Acquires a lock (dpll_lock)
869  * Return:
870  * * 0 on success
871  * * negative - error value
872  */
873 int
874 dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
875 		  const struct dpll_pin_ops *ops, void *priv)
876 {
877 	int ret;
878 
879 	if (WARN_ON(!ops) ||
880 	    WARN_ON(!ops->state_on_dpll_get) ||
881 	    WARN_ON(!ops->direction_get) ||
882 	    WARN_ON(ops->measured_freq_get &&
883 		    (!dpll_device_ops(dpll)->freq_monitor_get ||
884 		     !dpll_device_ops(dpll)->freq_monitor_set)) ||
885 	    WARN_ON(ops->supported_ffo && !ops->ffo_get))
886 		return -EINVAL;
887 
888 	mutex_lock(&dpll_lock);
889 
890 	/*
891 	 * For pins identified via firmware (pin->fwnode), allow registration
892 	 * even if the pin's (module, clock_id) differs from the target DPLL.
893 	 * For non-fwnode pins, require a strict (module, clock_id) match.
894 	 */
895 	if (!pin->fwnode &&
896 	    WARN_ON_ONCE(dpll->module != pin->module ||
897 			 dpll->clock_id != pin->clock_id)) {
898 		ret = -EINVAL;
899 		goto out_unlock;
900 	}
901 
902 	ret = __dpll_pin_register(dpll, pin, ops, priv, NULL);
903 out_unlock:
904 	mutex_unlock(&dpll_lock);
905 
906 	return ret;
907 }
908 EXPORT_SYMBOL_GPL(dpll_pin_register);
909 
910 static void dpll_pin_ref_sync_pair_del(u32 ref_sync_pin_id)
911 {
912 	struct dpll_pin *pin, *ref_sync_pin;
913 	unsigned long i;
914 
915 	xa_for_each(&dpll_pin_xa, i, pin) {
916 		ref_sync_pin = xa_load(&pin->ref_sync_pins, ref_sync_pin_id);
917 		if (ref_sync_pin) {
918 			xa_erase(&pin->ref_sync_pins, ref_sync_pin_id);
919 			__dpll_pin_change_ntf(pin);
920 		}
921 	}
922 }
923 
924 static void
925 __dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
926 		      const struct dpll_pin_ops *ops, void *priv, void *cookie)
927 {
928 	ASSERT_DPLL_PIN_REGISTERED(pin);
929 	dpll_pin_ref_sync_pair_del(pin->id);
930 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv, cookie);
931 	dpll_xa_ref_dpll_del(&pin->dpll_refs, dpll, ops, priv, cookie);
932 	if (xa_empty(&pin->dpll_refs))
933 		xa_clear_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
934 }
935 
936 /**
937  * dpll_pin_unregister - unregister dpll pin from dpll device
938  * @dpll: registered dpll pointer
939  * @pin: pointer to a pin
940  * @ops: ops for a dpll pin
941  * @priv: pointer to private information of owner
942  *
943  * Note: It does not free the memory
944  * Context: Acquires a lock (dpll_lock)
945  */
946 void dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
947 			 const struct dpll_pin_ops *ops, void *priv)
948 {
949 	if (WARN_ON(xa_empty(&dpll->pin_refs)))
950 		return;
951 	if (WARN_ON(!xa_empty(&pin->parent_refs)))
952 		return;
953 
954 	mutex_lock(&dpll_lock);
955 	dpll_pin_delete_ntf(pin);
956 	__dpll_pin_unregister(dpll, pin, ops, priv, NULL);
957 	mutex_unlock(&dpll_lock);
958 }
959 EXPORT_SYMBOL_GPL(dpll_pin_unregister);
960 
961 /**
962  * dpll_pin_on_pin_register - register a pin with a parent pin
963  * @parent: pointer to a parent pin
964  * @pin: pointer to a pin
965  * @ops: ops for a dpll pin
966  * @priv: pointer to private information of owner
967  *
968  * Register a pin with a parent pin, create references between them and
969  * between newly registered pin and dplls connected with a parent pin.
970  *
971  * Context: Acquires a lock (dpll_lock)
972  * Return:
973  * * 0 on success
974  * * negative - error value
975  */
976 int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
977 			     const struct dpll_pin_ops *ops, void *priv)
978 {
979 	struct dpll_pin_ref *ref;
980 	unsigned long i, stop;
981 	int ret;
982 
983 	if (WARN_ON(parent->prop.type != DPLL_PIN_TYPE_MUX))
984 		return -EINVAL;
985 
986 	if (WARN_ON(!ops) ||
987 	    WARN_ON(!ops->state_on_pin_get) ||
988 	    WARN_ON(!ops->direction_get))
989 		return -EINVAL;
990 
991 	mutex_lock(&dpll_lock);
992 	ret = dpll_xa_ref_pin_add(&pin->parent_refs, parent, ops, priv, pin);
993 	if (ret)
994 		goto unlock;
995 	xa_for_each(&parent->dpll_refs, i, ref) {
996 		ret = __dpll_pin_register(ref->dpll, pin, ops, priv, parent);
997 		if (ret) {
998 			stop = i;
999 			goto dpll_unregister;
1000 		}
1001 		dpll_pin_create_ntf(pin);
1002 	}
1003 	mutex_unlock(&dpll_lock);
1004 
1005 	return ret;
1006 
1007 dpll_unregister:
1008 	xa_for_each(&parent->dpll_refs, i, ref)
1009 		if (i < stop) {
1010 			__dpll_pin_unregister(ref->dpll, pin, ops, priv,
1011 					      parent);
1012 			dpll_pin_delete_ntf(pin);
1013 		}
1014 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv, pin);
1015 unlock:
1016 	mutex_unlock(&dpll_lock);
1017 	return ret;
1018 }
1019 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_register);
1020 
1021 /**
1022  * dpll_pin_on_pin_unregister - unregister dpll pin from a parent pin
1023  * @parent: pointer to a parent pin
1024  * @pin: pointer to a pin
1025  * @ops: ops for a dpll pin
1026  * @priv: pointer to private information of owner
1027  *
1028  * Context: Acquires a lock (dpll_lock)
1029  * Note: It does not free the memory
1030  */
1031 void dpll_pin_on_pin_unregister(struct dpll_pin *parent, struct dpll_pin *pin,
1032 				const struct dpll_pin_ops *ops, void *priv)
1033 {
1034 	struct dpll_pin_registration *reg;
1035 	struct dpll_pin_ref *ref;
1036 	unsigned long i;
1037 
1038 	mutex_lock(&dpll_lock);
1039 	dpll_pin_delete_ntf(pin);
1040 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv, pin);
1041 	xa_for_each(&pin->dpll_refs, i, ref) {
1042 		reg = dpll_pin_registration_find(ref, ops, priv, parent);
1043 		if (!reg)
1044 			continue;
1045 		__dpll_pin_unregister(ref->dpll, pin, ops, priv, parent);
1046 	}
1047 	mutex_unlock(&dpll_lock);
1048 }
1049 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_unregister);
1050 
1051 /**
1052  * dpll_pin_ref_sync_pair_add - create a reference sync signal pin pair
1053  * @pin: pin which produces the base frequency
1054  * @ref_sync_pin: pin which produces the sync signal
1055  *
1056  * Once pins are paired, the user-space configuration of reference sync pair
1057  * is possible.
1058  * Context: Acquires a lock (dpll_lock)
1059  * Return:
1060  * * 0 on success
1061  * * negative - error value
1062  */
1063 int dpll_pin_ref_sync_pair_add(struct dpll_pin *pin,
1064 			       struct dpll_pin *ref_sync_pin)
1065 {
1066 	int ret;
1067 
1068 	mutex_lock(&dpll_lock);
1069 	ret = xa_insert(&pin->ref_sync_pins, ref_sync_pin->id,
1070 			ref_sync_pin, GFP_KERNEL);
1071 	__dpll_pin_change_ntf(pin);
1072 	mutex_unlock(&dpll_lock);
1073 
1074 	return ret;
1075 }
1076 EXPORT_SYMBOL_GPL(dpll_pin_ref_sync_pair_add);
1077 
1078 static struct dpll_device_registration *
1079 dpll_device_registration_first(struct dpll_device *dpll)
1080 {
1081 	struct dpll_device_registration *reg;
1082 
1083 	reg = list_first_entry_or_null((struct list_head *)&dpll->registration_list,
1084 				       struct dpll_device_registration, list);
1085 	WARN_ON(!reg);
1086 	return reg;
1087 }
1088 
1089 void *dpll_priv(struct dpll_device *dpll)
1090 {
1091 	struct dpll_device_registration *reg;
1092 
1093 	reg = dpll_device_registration_first(dpll);
1094 	return reg->priv;
1095 }
1096 
1097 const struct dpll_device_ops *dpll_device_ops(struct dpll_device *dpll)
1098 {
1099 	struct dpll_device_registration *reg;
1100 
1101 	reg = dpll_device_registration_first(dpll);
1102 	return reg->ops;
1103 }
1104 
1105 static struct dpll_pin_registration *
1106 dpll_pin_registration_first(struct dpll_pin_ref *ref)
1107 {
1108 	struct dpll_pin_registration *reg;
1109 
1110 	reg = list_first_entry_or_null(&ref->registration_list,
1111 				       struct dpll_pin_registration, list);
1112 	WARN_ON(!reg);
1113 	return reg;
1114 }
1115 
1116 void *dpll_pin_on_dpll_priv(struct dpll_device *dpll,
1117 			    struct dpll_pin *pin)
1118 {
1119 	struct dpll_pin_registration *reg;
1120 	struct dpll_pin_ref *ref;
1121 
1122 	ref = xa_load(&dpll->pin_refs, pin->pin_idx);
1123 	if (!ref)
1124 		return NULL;
1125 	reg = dpll_pin_registration_first(ref);
1126 	return reg->priv;
1127 }
1128 
1129 void *dpll_pin_on_pin_priv(struct dpll_pin *parent,
1130 			   struct dpll_pin *pin)
1131 {
1132 	struct dpll_pin_registration *reg;
1133 	struct dpll_pin_ref *ref;
1134 
1135 	ref = xa_load(&pin->parent_refs, parent->pin_idx);
1136 	if (!ref)
1137 		return NULL;
1138 	reg = dpll_pin_registration_first(ref);
1139 	return reg->priv;
1140 }
1141 
1142 const struct dpll_pin_ops *dpll_pin_ops(struct dpll_pin_ref *ref)
1143 {
1144 	struct dpll_pin_registration *reg;
1145 
1146 	reg = dpll_pin_registration_first(ref);
1147 	return reg->ops;
1148 }
1149 
1150 static int __init dpll_init(void)
1151 {
1152 	int ret;
1153 
1154 	ret = genl_register_family(&dpll_nl_family);
1155 	if (ret)
1156 		goto error;
1157 
1158 	return 0;
1159 
1160 error:
1161 	mutex_destroy(&dpll_lock);
1162 	return ret;
1163 }
1164 
1165 static void __exit dpll_exit(void)
1166 {
1167 	genl_unregister_family(&dpll_nl_family);
1168 	mutex_destroy(&dpll_lock);
1169 }
1170 
1171 subsys_initcall(dpll_init);
1172 module_exit(dpll_exit);
1173