xref: /linux/drivers/dpll/dpll_core.c (revision bba2c3615bd6cfee7456d1130f2e6b01b3f4e9ba)
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, u64 src_clock_id,
76 		     unsigned long action)
77 {
78 	struct dpll_pin_notifier_info info = {
79 		.pin = pin,
80 		.id = pin->id,
81 		.idx = pin->pin_idx,
82 		.clock_id = pin->clock_id,
83 		.fwnode = pin->fwnode,
84 		.prop = &pin->prop,
85 		.src_clock_id = src_clock_id,
86 	};
87 
88 	call_dpll_notifiers(action, &info);
89 }
90 
91 static void dpll_device_tracker_alloc(struct dpll_device *dpll,
92 				      dpll_tracker *tracker)
93 {
94 #ifdef CONFIG_DPLL_REFCNT_TRACKER
95 	ref_tracker_alloc(&dpll->refcnt_tracker, tracker, GFP_KERNEL);
96 #endif
97 }
98 
99 static void dpll_device_tracker_free(struct dpll_device *dpll,
100 				     dpll_tracker *tracker)
101 {
102 #ifdef CONFIG_DPLL_REFCNT_TRACKER
103 	ref_tracker_free(&dpll->refcnt_tracker, tracker);
104 #endif
105 }
106 
107 static void __dpll_device_hold(struct dpll_device *dpll, dpll_tracker *tracker)
108 {
109 	dpll_device_tracker_alloc(dpll, tracker);
110 	refcount_inc(&dpll->refcount);
111 }
112 
113 static void __dpll_device_put(struct dpll_device *dpll, dpll_tracker *tracker)
114 {
115 	dpll_device_tracker_free(dpll, tracker);
116 	if (refcount_dec_and_test(&dpll->refcount)) {
117 		ASSERT_DPLL_NOT_REGISTERED(dpll);
118 		WARN_ON_ONCE(!xa_empty(&dpll->pin_refs));
119 		xa_destroy(&dpll->pin_refs);
120 		xa_erase(&dpll_device_xa, dpll->id);
121 		WARN_ON(!list_empty(&dpll->registration_list));
122 		ref_tracker_dir_exit(&dpll->refcnt_tracker);
123 		kfree(dpll);
124 	}
125 }
126 
127 static void dpll_pin_tracker_alloc(struct dpll_pin *pin, dpll_tracker *tracker)
128 {
129 #ifdef CONFIG_DPLL_REFCNT_TRACKER
130 	ref_tracker_alloc(&pin->refcnt_tracker, tracker, GFP_KERNEL);
131 #endif
132 }
133 
134 static void dpll_pin_tracker_free(struct dpll_pin *pin, dpll_tracker *tracker)
135 {
136 #ifdef CONFIG_DPLL_REFCNT_TRACKER
137 	ref_tracker_free(&pin->refcnt_tracker, tracker);
138 #endif
139 }
140 
141 static void __dpll_pin_hold(struct dpll_pin *pin, dpll_tracker *tracker)
142 {
143 	dpll_pin_tracker_alloc(pin, tracker);
144 	refcount_inc(&pin->refcount);
145 }
146 
147 static void dpll_pin_idx_free(u32 pin_idx);
148 static void dpll_pin_prop_free(struct dpll_pin_properties *prop);
149 
150 static void __dpll_pin_put(struct dpll_pin *pin, dpll_tracker *tracker)
151 {
152 	dpll_pin_tracker_free(pin, tracker);
153 	if (refcount_dec_and_test(&pin->refcount)) {
154 		xa_erase(&dpll_pin_xa, pin->id);
155 		xa_destroy(&pin->dpll_refs);
156 		xa_destroy(&pin->parent_refs);
157 		xa_destroy(&pin->ref_sync_pins);
158 		dpll_pin_prop_free(&pin->prop);
159 		fwnode_handle_put(pin->fwnode);
160 		dpll_pin_idx_free(pin->pin_idx);
161 		ref_tracker_dir_exit(&pin->refcnt_tracker);
162 		kfree_rcu(pin, rcu);
163 	}
164 }
165 
166 struct dpll_device *dpll_device_get_by_id(int id)
167 {
168 	if (xa_get_mark(&dpll_device_xa, id, DPLL_REGISTERED))
169 		return xa_load(&dpll_device_xa, id);
170 
171 	return NULL;
172 }
173 
174 static struct dpll_pin_registration *
175 dpll_pin_registration_find(struct dpll_pin_ref *ref,
176 			   const struct dpll_pin_ops *ops, void *priv,
177 			   void *cookie)
178 {
179 	struct dpll_pin_registration *reg;
180 
181 	list_for_each_entry(reg, &ref->registration_list, list) {
182 		if (reg->ops == ops && reg->priv == priv &&
183 		    reg->cookie == cookie)
184 			return reg;
185 	}
186 	return NULL;
187 }
188 
189 static int
190 dpll_xa_ref_pin_add(struct xarray *xa_pins, struct dpll_pin *pin,
191 		    const struct dpll_pin_ops *ops, void *priv,
192 		    void *cookie)
193 {
194 	struct dpll_pin_registration *reg;
195 	struct dpll_pin_ref *ref;
196 	bool ref_exists = false;
197 	unsigned long i;
198 	int ret;
199 
200 	xa_for_each(xa_pins, i, ref) {
201 		if (ref->pin != pin)
202 			continue;
203 		reg = dpll_pin_registration_find(ref, ops, priv, cookie);
204 		if (reg)
205 			return -EEXIST;
206 		ref_exists = true;
207 		break;
208 	}
209 
210 	if (!ref_exists) {
211 		ref = kzalloc_obj(*ref);
212 		if (!ref)
213 			return -ENOMEM;
214 		ref->pin = pin;
215 		INIT_LIST_HEAD(&ref->registration_list);
216 		ret = xa_insert(xa_pins, pin->pin_idx, ref, GFP_KERNEL);
217 		if (ret) {
218 			kfree(ref);
219 			return ret;
220 		}
221 		refcount_set(&ref->refcount, 1);
222 	}
223 
224 	reg = kzalloc_obj(*reg);
225 	if (!reg) {
226 		if (!ref_exists) {
227 			xa_erase(xa_pins, pin->pin_idx);
228 			kfree(ref);
229 		}
230 		return -ENOMEM;
231 	}
232 	reg->ops = ops;
233 	reg->priv = priv;
234 	reg->cookie = cookie;
235 	__dpll_pin_hold(pin, &reg->tracker);
236 	if (ref_exists)
237 		refcount_inc(&ref->refcount);
238 	list_add_tail(&reg->list, &ref->registration_list);
239 
240 	return 0;
241 }
242 
243 static int dpll_xa_ref_pin_del(struct xarray *xa_pins, struct dpll_pin *pin,
244 			       const struct dpll_pin_ops *ops, void *priv,
245 			       void *cookie)
246 {
247 	struct dpll_pin_registration *reg;
248 	struct dpll_pin_ref *ref;
249 	unsigned long i;
250 
251 	xa_for_each(xa_pins, i, ref) {
252 		if (ref->pin != pin)
253 			continue;
254 		reg = dpll_pin_registration_find(ref, ops, priv, cookie);
255 		if (WARN_ON(!reg))
256 			return -EINVAL;
257 		list_del(&reg->list);
258 		__dpll_pin_put(pin, &reg->tracker);
259 		kfree(reg);
260 		if (refcount_dec_and_test(&ref->refcount)) {
261 			xa_erase(xa_pins, i);
262 			WARN_ON(!list_empty(&ref->registration_list));
263 			kfree(ref);
264 		}
265 		return 0;
266 	}
267 
268 	return -EINVAL;
269 }
270 
271 static int
272 dpll_xa_ref_dpll_add(struct xarray *xa_dplls, struct dpll_device *dpll,
273 		     const struct dpll_pin_ops *ops, void *priv, void *cookie)
274 {
275 	struct dpll_pin_registration *reg;
276 	struct dpll_pin_ref *ref;
277 	bool ref_exists = false;
278 	unsigned long i;
279 	int ret;
280 
281 	xa_for_each(xa_dplls, i, ref) {
282 		if (ref->dpll != dpll)
283 			continue;
284 		reg = dpll_pin_registration_find(ref, ops, priv, cookie);
285 		if (reg)
286 			return -EEXIST;
287 		ref_exists = true;
288 		break;
289 	}
290 
291 	if (!ref_exists) {
292 		ref = kzalloc_obj(*ref);
293 		if (!ref)
294 			return -ENOMEM;
295 		ref->dpll = dpll;
296 		INIT_LIST_HEAD(&ref->registration_list);
297 		ret = xa_insert(xa_dplls, dpll->id, ref, GFP_KERNEL);
298 		if (ret) {
299 			kfree(ref);
300 			return ret;
301 		}
302 		refcount_set(&ref->refcount, 1);
303 	}
304 
305 	reg = kzalloc_obj(*reg);
306 	if (!reg) {
307 		if (!ref_exists) {
308 			xa_erase(xa_dplls, dpll->id);
309 			kfree(ref);
310 		}
311 		return -ENOMEM;
312 	}
313 	reg->ops = ops;
314 	reg->priv = priv;
315 	reg->cookie = cookie;
316 	__dpll_device_hold(dpll, &reg->tracker);
317 	if (ref_exists)
318 		refcount_inc(&ref->refcount);
319 	list_add_tail(&reg->list, &ref->registration_list);
320 
321 	return 0;
322 }
323 
324 static void
325 dpll_xa_ref_dpll_del(struct xarray *xa_dplls, struct dpll_device *dpll,
326 		     const struct dpll_pin_ops *ops, void *priv, void *cookie)
327 {
328 	struct dpll_pin_registration *reg;
329 	struct dpll_pin_ref *ref;
330 	unsigned long i;
331 
332 	xa_for_each(xa_dplls, i, ref) {
333 		if (ref->dpll != dpll)
334 			continue;
335 		reg = dpll_pin_registration_find(ref, ops, priv, cookie);
336 		if (WARN_ON(!reg))
337 			return;
338 		list_del(&reg->list);
339 		__dpll_device_put(dpll, &reg->tracker);
340 		kfree(reg);
341 		if (refcount_dec_and_test(&ref->refcount)) {
342 			xa_erase(xa_dplls, i);
343 			WARN_ON(!list_empty(&ref->registration_list));
344 			kfree(ref);
345 		}
346 		return;
347 	}
348 }
349 
350 struct dpll_pin_ref *dpll_xa_ref_dpll_first(struct xarray *xa_refs)
351 {
352 	struct dpll_pin_ref *ref;
353 	unsigned long i = 0;
354 
355 	ref = xa_find(xa_refs, &i, ULONG_MAX, XA_PRESENT);
356 	WARN_ON(!ref);
357 	return ref;
358 }
359 
360 static struct dpll_device *
361 dpll_device_alloc(const u64 clock_id, u32 device_idx, struct module *module)
362 {
363 	struct dpll_device *dpll;
364 	int ret;
365 
366 	dpll = kzalloc_obj(*dpll);
367 	if (!dpll)
368 		return ERR_PTR(-ENOMEM);
369 	refcount_set(&dpll->refcount, 1);
370 	INIT_LIST_HEAD(&dpll->registration_list);
371 	dpll->device_idx = device_idx;
372 	dpll->clock_id = clock_id;
373 	dpll->module = module;
374 	ret = xa_alloc_cyclic(&dpll_device_xa, &dpll->id, dpll, xa_limit_32b,
375 			      &dpll_device_xa_id, GFP_KERNEL);
376 	if (ret < 0) {
377 		kfree(dpll);
378 		return ERR_PTR(ret);
379 	}
380 	xa_init_flags(&dpll->pin_refs, XA_FLAGS_ALLOC);
381 	ref_tracker_dir_init(&dpll->refcnt_tracker, 128, "dpll_device");
382 
383 	return dpll;
384 }
385 
386 /**
387  * dpll_device_get - find existing or create new dpll device
388  * @clock_id: clock_id of creator
389  * @device_idx: idx given by device driver
390  * @module: reference to registering module
391  * @tracker: tracking object for the acquired reference
392  *
393  * Get existing object of a dpll device, unique for given arguments.
394  * Create new if doesn't exist yet.
395  *
396  * Context: Acquires a lock (dpll_lock)
397  * Return:
398  * * valid dpll_device struct pointer if succeeded
399  * * ERR_PTR(X) - error
400  */
401 struct dpll_device *
402 dpll_device_get(u64 clock_id, u32 device_idx, struct module *module,
403 		dpll_tracker *tracker)
404 {
405 	struct dpll_device *dpll, *ret = NULL;
406 	unsigned long index;
407 
408 	mutex_lock(&dpll_lock);
409 	xa_for_each(&dpll_device_xa, index, dpll) {
410 		if (dpll->clock_id == clock_id &&
411 		    dpll->device_idx == device_idx &&
412 		    dpll->module == module) {
413 			__dpll_device_hold(dpll, tracker);
414 			ret = dpll;
415 			break;
416 		}
417 	}
418 	if (!ret) {
419 		ret = dpll_device_alloc(clock_id, device_idx, module);
420 		if (!IS_ERR(ret))
421 			dpll_device_tracker_alloc(ret, tracker);
422 	}
423 
424 	mutex_unlock(&dpll_lock);
425 
426 	return ret;
427 }
428 EXPORT_SYMBOL_GPL(dpll_device_get);
429 
430 /**
431  * dpll_device_put - decrease the refcount and free memory if possible
432  * @dpll: dpll_device struct pointer
433  * @tracker: tracking object for the acquired reference
434  *
435  * Context: Acquires a lock (dpll_lock)
436  * Drop reference for a dpll device, if all references are gone, delete
437  * dpll device object.
438  */
439 void dpll_device_put(struct dpll_device *dpll, dpll_tracker *tracker)
440 {
441 	mutex_lock(&dpll_lock);
442 	__dpll_device_put(dpll, tracker);
443 	mutex_unlock(&dpll_lock);
444 }
445 EXPORT_SYMBOL_GPL(dpll_device_put);
446 
447 static struct dpll_device_registration *
448 dpll_device_registration_find(struct dpll_device *dpll,
449 			      const struct dpll_device_ops *ops, void *priv)
450 {
451 	struct dpll_device_registration *reg;
452 
453 	list_for_each_entry(reg, &dpll->registration_list, list) {
454 		if (reg->ops == ops && reg->priv == priv)
455 			return reg;
456 	}
457 	return NULL;
458 }
459 
460 /**
461  * dpll_device_register - register the dpll device in the subsystem
462  * @dpll: pointer to a dpll
463  * @type: type of a dpll
464  * @ops: ops for a dpll device
465  * @priv: pointer to private information of owner
466  *
467  * Make dpll device available for user space.
468  *
469  * Context: Acquires a lock (dpll_lock)
470  * Return:
471  * * 0 on success
472  * * negative - error value
473  */
474 int dpll_device_register(struct dpll_device *dpll, enum dpll_type type,
475 			 const struct dpll_device_ops *ops, void *priv)
476 {
477 	struct dpll_device_registration *reg;
478 	bool first_registration = false;
479 
480 	if (WARN_ON(!ops))
481 		return -EINVAL;
482 	if (WARN_ON(!ops->mode_get))
483 		return -EINVAL;
484 	if (WARN_ON(!ops->lock_status_get))
485 		return -EINVAL;
486 	if (WARN_ON(type < DPLL_TYPE_PPS || type > DPLL_TYPE_MAX))
487 		return -EINVAL;
488 
489 	mutex_lock(&dpll_lock);
490 	reg = dpll_device_registration_find(dpll, ops, priv);
491 	if (reg) {
492 		mutex_unlock(&dpll_lock);
493 		return -EEXIST;
494 	}
495 
496 	reg = kzalloc_obj(*reg);
497 	if (!reg) {
498 		mutex_unlock(&dpll_lock);
499 		return -ENOMEM;
500 	}
501 	reg->ops = ops;
502 	reg->priv = priv;
503 	dpll->type = type;
504 	__dpll_device_hold(dpll, &reg->tracker);
505 	first_registration = list_empty(&dpll->registration_list);
506 	list_add_tail(&reg->list, &dpll->registration_list);
507 	if (!first_registration) {
508 		mutex_unlock(&dpll_lock);
509 		return 0;
510 	}
511 
512 	xa_set_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
513 	dpll_device_create_ntf(dpll);
514 	mutex_unlock(&dpll_lock);
515 
516 	return 0;
517 }
518 EXPORT_SYMBOL_GPL(dpll_device_register);
519 
520 /**
521  * dpll_device_unregister - unregister dpll device
522  * @dpll: registered dpll pointer
523  * @ops: ops for a dpll device
524  * @priv: pointer to private information of owner
525  *
526  * Unregister device, make it unavailable for userspace.
527  * Note: It does not free the memory
528  * Context: Acquires a lock (dpll_lock)
529  */
530 void dpll_device_unregister(struct dpll_device *dpll,
531 			    const struct dpll_device_ops *ops, void *priv)
532 {
533 	struct dpll_device_registration *reg;
534 
535 	mutex_lock(&dpll_lock);
536 	ASSERT_DPLL_REGISTERED(dpll);
537 	dpll_device_delete_ntf(dpll);
538 	reg = dpll_device_registration_find(dpll, ops, priv);
539 	if (WARN_ON(!reg)) {
540 		mutex_unlock(&dpll_lock);
541 		return;
542 	}
543 	list_del(&reg->list);
544 	__dpll_device_put(dpll, &reg->tracker);
545 	kfree(reg);
546 
547 	if (!list_empty(&dpll->registration_list)) {
548 		mutex_unlock(&dpll_lock);
549 		return;
550 	}
551 	xa_clear_mark(&dpll_device_xa, dpll->id, DPLL_REGISTERED);
552 	mutex_unlock(&dpll_lock);
553 }
554 EXPORT_SYMBOL_GPL(dpll_device_unregister);
555 
556 static int dpll_pin_idx_alloc(u32 *pin_idx)
557 {
558 	int ret;
559 
560 	if (!pin_idx)
561 		return -EINVAL;
562 
563 	/* Alloc unique number from IDA. Number belongs to <0, INT_MAX> range */
564 	ret = ida_alloc(&dpll_pin_idx_ida, GFP_KERNEL);
565 	if (ret < 0)
566 		return ret;
567 
568 	/* Map the value to dynamic pin index range <INT_MAX+1, U32_MAX> */
569 	*pin_idx = (u32)ret + INT_MAX + 1;
570 
571 	return 0;
572 }
573 
574 static void dpll_pin_idx_free(u32 pin_idx)
575 {
576 	if (pin_idx <= INT_MAX)
577 		return; /* Not a dynamic pin index */
578 
579 	/* Map the index value from dynamic pin index range to IDA range and
580 	 * free it.
581 	 */
582 	pin_idx -= (u32)INT_MAX + 1;
583 	ida_free(&dpll_pin_idx_ida, pin_idx);
584 }
585 
586 static void dpll_pin_prop_free(struct dpll_pin_properties *prop)
587 {
588 	kfree(prop->package_label);
589 	kfree(prop->panel_label);
590 	kfree(prop->board_label);
591 	kfree(prop->freq_supported);
592 }
593 
594 static int dpll_pin_prop_dup(const struct dpll_pin_properties *src,
595 			     struct dpll_pin_properties *dst)
596 {
597 	if (WARN_ON(src->freq_supported && !src->freq_supported_num))
598 		return -EINVAL;
599 
600 	memcpy(dst, src, sizeof(*dst));
601 	if (src->freq_supported) {
602 		size_t freq_size = src->freq_supported_num *
603 				   sizeof(*src->freq_supported);
604 		dst->freq_supported = kmemdup(src->freq_supported,
605 					      freq_size, GFP_KERNEL);
606 		if (!dst->freq_supported)
607 			return -ENOMEM;
608 	}
609 	if (src->board_label) {
610 		dst->board_label = kstrdup(src->board_label, GFP_KERNEL);
611 		if (!dst->board_label)
612 			goto err_board_label;
613 	}
614 	if (src->panel_label) {
615 		dst->panel_label = kstrdup(src->panel_label, GFP_KERNEL);
616 		if (!dst->panel_label)
617 			goto err_panel_label;
618 	}
619 	if (src->package_label) {
620 		dst->package_label = kstrdup(src->package_label, GFP_KERNEL);
621 		if (!dst->package_label)
622 			goto err_package_label;
623 	}
624 
625 	return 0;
626 
627 err_package_label:
628 	kfree(dst->panel_label);
629 err_panel_label:
630 	kfree(dst->board_label);
631 err_board_label:
632 	kfree(dst->freq_supported);
633 	return -ENOMEM;
634 }
635 
636 static struct dpll_pin *
637 dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
638 	       const struct dpll_pin_properties *prop)
639 {
640 	struct dpll_pin *pin;
641 	int ret;
642 
643 	if (pin_idx == DPLL_PIN_IDX_UNSPEC) {
644 		ret = dpll_pin_idx_alloc(&pin_idx);
645 		if (ret)
646 			return ERR_PTR(ret);
647 	} else if (pin_idx > INT_MAX) {
648 		return ERR_PTR(-EINVAL);
649 	}
650 	pin = kzalloc_obj(*pin);
651 	if (!pin) {
652 		ret = -ENOMEM;
653 		goto err_pin_alloc;
654 	}
655 	pin->pin_idx = pin_idx;
656 	pin->clock_id = clock_id;
657 	pin->module = module;
658 	strscpy(pin->module_name, module_name(module));
659 	if (WARN_ON(prop->type < DPLL_PIN_TYPE_MUX ||
660 		    prop->type > DPLL_PIN_TYPE_MAX)) {
661 		ret = -EINVAL;
662 		goto err_pin_prop;
663 	}
664 	ret = dpll_pin_prop_dup(prop, &pin->prop);
665 	if (ret)
666 		goto err_pin_prop;
667 	refcount_set(&pin->refcount, 1);
668 	xa_init_flags(&pin->dpll_refs, XA_FLAGS_ALLOC);
669 	xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
670 	xa_init_flags(&pin->ref_sync_pins, XA_FLAGS_ALLOC);
671 	ret = xa_alloc_cyclic(&dpll_pin_xa, &pin->id, pin, xa_limit_32b,
672 			      &dpll_pin_xa_id, GFP_KERNEL);
673 	if (ret < 0)
674 		goto err_xa_alloc;
675 	ref_tracker_dir_init(&pin->refcnt_tracker, 128, "dpll_pin");
676 	return pin;
677 err_xa_alloc:
678 	xa_destroy(&pin->dpll_refs);
679 	xa_destroy(&pin->parent_refs);
680 	xa_destroy(&pin->ref_sync_pins);
681 	dpll_pin_prop_free(&pin->prop);
682 err_pin_prop:
683 	kfree(pin);
684 err_pin_alloc:
685 	dpll_pin_idx_free(pin_idx);
686 	return ERR_PTR(ret);
687 }
688 
689 static void dpll_netdev_pin_assign(struct net_device *dev, struct dpll_pin *dpll_pin)
690 {
691 	rtnl_lock();
692 	rcu_assign_pointer(dev->dpll_pin, dpll_pin);
693 	rtnl_unlock();
694 }
695 
696 void dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)
697 {
698 	WARN_ON(!dpll_pin);
699 	dpll_netdev_pin_assign(dev, dpll_pin);
700 }
701 EXPORT_SYMBOL(dpll_netdev_pin_set);
702 
703 void dpll_netdev_pin_clear(struct net_device *dev)
704 {
705 	dpll_netdev_pin_assign(dev, NULL);
706 }
707 EXPORT_SYMBOL(dpll_netdev_pin_clear);
708 
709 int register_dpll_notifier(struct notifier_block *nb)
710 {
711 	int ret;
712 
713 	mutex_lock(&dpll_lock);
714 	ret = raw_notifier_chain_register(&dpll_notifier_chain, nb);
715 	mutex_unlock(&dpll_lock);
716 	return ret;
717 }
718 EXPORT_SYMBOL_GPL(register_dpll_notifier);
719 
720 int unregister_dpll_notifier(struct notifier_block *nb)
721 {
722 	int ret;
723 
724 	mutex_lock(&dpll_lock);
725 	ret = raw_notifier_chain_unregister(&dpll_notifier_chain, nb);
726 	mutex_unlock(&dpll_lock);
727 	return ret;
728 }
729 EXPORT_SYMBOL_GPL(unregister_dpll_notifier);
730 
731 /**
732  * dpll_pin_get - find existing or create new dpll pin
733  * @clock_id: clock_id of creator
734  * @pin_idx: idx given by dev driver
735  * @module: reference to registering module
736  * @prop: dpll pin properties
737  * @tracker: tracking object for the acquired reference
738  *
739  * Get existing object of a pin (unique for given arguments) or create new
740  * if doesn't exist yet.
741  *
742  * Context: Acquires a lock (dpll_lock)
743  * Return:
744  * * valid allocated dpll_pin struct pointer if succeeded
745  * * ERR_PTR(X) - error
746  */
747 struct dpll_pin *
748 dpll_pin_get(u64 clock_id, u32 pin_idx, struct module *module,
749 	     const struct dpll_pin_properties *prop, dpll_tracker *tracker)
750 {
751 	struct dpll_pin *pos, *ret = NULL;
752 	unsigned long i;
753 
754 	mutex_lock(&dpll_lock);
755 	xa_for_each(&dpll_pin_xa, i, pos) {
756 		if (pos->clock_id == clock_id &&
757 		    pos->pin_idx == pin_idx &&
758 		    pos->module == module) {
759 			__dpll_pin_hold(pos, tracker);
760 			ret = pos;
761 			break;
762 		}
763 	}
764 	if (!ret) {
765 		ret = dpll_pin_alloc(clock_id, pin_idx, module, prop);
766 		if (!IS_ERR(ret))
767 			dpll_pin_tracker_alloc(ret, tracker);
768 	}
769 	mutex_unlock(&dpll_lock);
770 
771 	return ret;
772 }
773 EXPORT_SYMBOL_GPL(dpll_pin_get);
774 
775 /**
776  * dpll_pin_put - decrease the refcount and free memory if possible
777  * @pin: pointer to a pin to be put
778  * @tracker: tracking object for the acquired reference
779  *
780  * Drop reference for a pin, if all references are gone, delete pin object.
781  *
782  * Context: Acquires a lock (dpll_lock)
783  */
784 void dpll_pin_put(struct dpll_pin *pin, dpll_tracker *tracker)
785 {
786 	mutex_lock(&dpll_lock);
787 	__dpll_pin_put(pin, tracker);
788 	mutex_unlock(&dpll_lock);
789 }
790 EXPORT_SYMBOL_GPL(dpll_pin_put);
791 
792 /**
793  * dpll_pin_fwnode_set - set dpll pin firmware node reference
794  * @pin: pointer to a dpll pin
795  * @fwnode: firmware node handle
796  *
797  * Set firmware node handle for the given dpll pin.
798  */
799 void dpll_pin_fwnode_set(struct dpll_pin *pin, struct fwnode_handle *fwnode)
800 {
801 	mutex_lock(&dpll_lock);
802 	fwnode_handle_put(pin->fwnode); /* Drop fwnode previously set */
803 	pin->fwnode = fwnode_handle_get(fwnode);
804 	mutex_unlock(&dpll_lock);
805 }
806 EXPORT_SYMBOL_GPL(dpll_pin_fwnode_set);
807 
808 /**
809  * fwnode_dpll_pin_find - find dpll pin by firmware node reference
810  * @fwnode: reference to firmware node
811  * @tracker: tracking object for the acquired reference
812  *
813  * Get existing object of a pin that is associated with given firmware node
814  * reference.
815  *
816  * Context: Acquires a lock (dpll_lock)
817  * Return:
818  * * valid dpll_pin pointer on success
819  * * NULL when no such pin exists
820  */
821 struct dpll_pin *fwnode_dpll_pin_find(struct fwnode_handle *fwnode,
822 				      dpll_tracker *tracker)
823 {
824 	struct dpll_pin *pin, *ret = NULL;
825 	unsigned long index;
826 
827 	mutex_lock(&dpll_lock);
828 	xa_for_each(&dpll_pin_xa, index, pin) {
829 		if (pin->fwnode == fwnode) {
830 			__dpll_pin_hold(pin, tracker);
831 			ret = pin;
832 			break;
833 		}
834 	}
835 	mutex_unlock(&dpll_lock);
836 
837 	return ret;
838 }
839 EXPORT_SYMBOL_GPL(fwnode_dpll_pin_find);
840 
841 static int
842 __dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
843 		    const struct dpll_pin_ops *ops, void *priv, void *cookie)
844 {
845 	int ret;
846 
847 	ret = dpll_xa_ref_pin_add(&dpll->pin_refs, pin, ops, priv, cookie);
848 	if (ret)
849 		return ret;
850 	ret = dpll_xa_ref_dpll_add(&pin->dpll_refs, dpll, ops, priv, cookie);
851 	if (ret)
852 		goto ref_pin_del;
853 	xa_set_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
854 	dpll_pin_create_ntf(pin, dpll->clock_id);
855 
856 	return ret;
857 
858 ref_pin_del:
859 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv, cookie);
860 	return ret;
861 }
862 
863 /**
864  * dpll_pin_register - register the dpll pin in the subsystem
865  * @dpll: pointer to a dpll
866  * @pin: pointer to a dpll pin
867  * @ops: ops for a dpll pin ops
868  * @priv: pointer to private information of owner
869  *
870  * Context: Acquires a lock (dpll_lock)
871  * Return:
872  * * 0 on success
873  * * negative - error value
874  */
875 int
876 dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
877 		  const struct dpll_pin_ops *ops, void *priv)
878 {
879 	int ret;
880 
881 	if (WARN_ON(!ops) ||
882 	    WARN_ON(!ops->state_on_dpll_get) ||
883 	    WARN_ON(!ops->direction_get) ||
884 	    WARN_ON(ops->measured_freq_get &&
885 		    (!dpll_device_ops(dpll)->freq_monitor_get ||
886 		     !dpll_device_ops(dpll)->freq_monitor_set)) ||
887 	    WARN_ON(ops->supported_ffo && !ops->ffo_get))
888 		return -EINVAL;
889 
890 	mutex_lock(&dpll_lock);
891 
892 	/*
893 	 * For pins identified via firmware (pin->fwnode), allow registration
894 	 * even if the pin's (module, clock_id) differs from the target DPLL.
895 	 * For non-fwnode pins, require a strict (module, clock_id) match.
896 	 */
897 	if (!pin->fwnode &&
898 	    WARN_ON_ONCE(dpll->module != pin->module ||
899 			 dpll->clock_id != pin->clock_id)) {
900 		ret = -EINVAL;
901 		goto out_unlock;
902 	}
903 
904 	ret = __dpll_pin_register(dpll, pin, ops, priv, NULL);
905 out_unlock:
906 	mutex_unlock(&dpll_lock);
907 
908 	return ret;
909 }
910 EXPORT_SYMBOL_GPL(dpll_pin_register);
911 
912 static void dpll_pin_ref_sync_pair_del(u32 ref_sync_pin_id)
913 {
914 	struct dpll_pin *pin, *ref_sync_pin;
915 	unsigned long i;
916 
917 	xa_for_each(&dpll_pin_xa, i, pin) {
918 		ref_sync_pin = xa_load(&pin->ref_sync_pins, ref_sync_pin_id);
919 		if (ref_sync_pin) {
920 			xa_erase(&pin->ref_sync_pins, ref_sync_pin_id);
921 			__dpll_pin_change_ntf(pin);
922 		}
923 	}
924 }
925 
926 static void
927 __dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
928 		      const struct dpll_pin_ops *ops, void *priv, void *cookie)
929 {
930 	ASSERT_DPLL_PIN_REGISTERED(pin);
931 	dpll_pin_delete_ntf(pin, dpll->clock_id);
932 	dpll_xa_ref_pin_del(&dpll->pin_refs, pin, ops, priv, cookie);
933 	dpll_xa_ref_dpll_del(&pin->dpll_refs, dpll, ops, priv, cookie);
934 	if (xa_empty(&pin->dpll_refs)) {
935 		dpll_pin_ref_sync_pair_del(pin->id);
936 		xa_clear_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED);
937 	}
938 }
939 
940 /**
941  * dpll_pin_unregister - unregister dpll pin from dpll device
942  * @dpll: registered dpll pointer
943  * @pin: pointer to a pin
944  * @ops: ops for a dpll pin
945  * @priv: pointer to private information of owner
946  *
947  * Note: It does not free the memory
948  * Context: Acquires a lock (dpll_lock)
949  */
950 void dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
951 			 const struct dpll_pin_ops *ops, void *priv)
952 {
953 	if (WARN_ON(xa_empty(&dpll->pin_refs)))
954 		return;
955 	if (WARN_ON(!xa_empty(&pin->parent_refs)))
956 		return;
957 
958 	mutex_lock(&dpll_lock);
959 	__dpll_pin_unregister(dpll, pin, ops, priv, NULL);
960 	mutex_unlock(&dpll_lock);
961 }
962 EXPORT_SYMBOL_GPL(dpll_pin_unregister);
963 
964 /**
965  * dpll_pin_on_pin_register - register a pin with a parent pin
966  * @parent: pointer to a parent pin
967  * @pin: pointer to a pin
968  * @ops: ops for a dpll pin
969  * @priv: pointer to private information of owner
970  *
971  * Register a pin with a parent pin, create references between them and
972  * between newly registered pin and dplls connected with a parent pin.
973  *
974  * Context: Acquires a lock (dpll_lock)
975  * Return:
976  * * 0 on success
977  * * negative - error value
978  */
979 int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
980 			     const struct dpll_pin_ops *ops, void *priv)
981 {
982 	struct dpll_pin_ref *ref;
983 	unsigned long i, stop;
984 	int ret;
985 
986 	if (WARN_ON(parent->prop.type != DPLL_PIN_TYPE_MUX))
987 		return -EINVAL;
988 
989 	if (WARN_ON(!ops) ||
990 	    WARN_ON(!ops->state_on_pin_get) ||
991 	    WARN_ON(!ops->direction_get))
992 		return -EINVAL;
993 
994 	mutex_lock(&dpll_lock);
995 	ret = dpll_xa_ref_pin_add(&pin->parent_refs, parent, ops, priv, pin);
996 	if (ret)
997 		goto unlock;
998 	xa_for_each(&parent->dpll_refs, i, ref) {
999 		ret = __dpll_pin_register(ref->dpll, pin, ops, priv, parent);
1000 		if (ret) {
1001 			stop = i;
1002 			goto dpll_unregister;
1003 		}
1004 		dpll_pin_create_ntf(pin, parent->clock_id);
1005 	}
1006 	mutex_unlock(&dpll_lock);
1007 
1008 	return ret;
1009 
1010 dpll_unregister:
1011 	xa_for_each(&parent->dpll_refs, i, ref)
1012 		if (i < stop) {
1013 			dpll_pin_delete_ntf(pin, parent->clock_id);
1014 			__dpll_pin_unregister(ref->dpll, pin, ops, priv,
1015 					      parent);
1016 		}
1017 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv, pin);
1018 unlock:
1019 	mutex_unlock(&dpll_lock);
1020 	return ret;
1021 }
1022 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_register);
1023 
1024 /**
1025  * dpll_pin_on_pin_unregister - unregister dpll pin from a parent pin
1026  * @parent: pointer to a parent pin
1027  * @pin: pointer to a pin
1028  * @ops: ops for a dpll pin
1029  * @priv: pointer to private information of owner
1030  *
1031  * Context: Acquires a lock (dpll_lock)
1032  * Note: It does not free the memory
1033  */
1034 void dpll_pin_on_pin_unregister(struct dpll_pin *parent, struct dpll_pin *pin,
1035 				const struct dpll_pin_ops *ops, void *priv)
1036 {
1037 	struct dpll_pin_registration *reg;
1038 	struct dpll_pin_ref *ref;
1039 	unsigned long i;
1040 
1041 	mutex_lock(&dpll_lock);
1042 	xa_for_each(&pin->dpll_refs, i, ref) {
1043 		reg = dpll_pin_registration_find(ref, ops, priv, parent);
1044 		if (!reg)
1045 			continue;
1046 		dpll_pin_delete_ntf(pin, parent->clock_id);
1047 		__dpll_pin_unregister(ref->dpll, pin, ops, priv, parent);
1048 	}
1049 	dpll_xa_ref_pin_del(&pin->parent_refs, parent, ops, priv, pin);
1050 	mutex_unlock(&dpll_lock);
1051 }
1052 EXPORT_SYMBOL_GPL(dpll_pin_on_pin_unregister);
1053 
1054 /**
1055  * dpll_pin_ref_sync_pair_add - create a reference sync signal pin pair
1056  * @pin: pin which produces the base frequency
1057  * @ref_sync_pin: pin which produces the sync signal
1058  *
1059  * Once pins are paired, the user-space configuration of reference sync pair
1060  * is possible.
1061  * Context: Acquires a lock (dpll_lock)
1062  * Return:
1063  * * 0 on success
1064  * * negative - error value
1065  */
1066 int dpll_pin_ref_sync_pair_add(struct dpll_pin *pin,
1067 			       struct dpll_pin *ref_sync_pin)
1068 {
1069 	int ret;
1070 
1071 	mutex_lock(&dpll_lock);
1072 	ret = xa_insert(&pin->ref_sync_pins, ref_sync_pin->id,
1073 			ref_sync_pin, GFP_KERNEL);
1074 	__dpll_pin_change_ntf(pin);
1075 	mutex_unlock(&dpll_lock);
1076 
1077 	return ret;
1078 }
1079 EXPORT_SYMBOL_GPL(dpll_pin_ref_sync_pair_add);
1080 
1081 static struct dpll_device_registration *
1082 dpll_device_registration_first(struct dpll_device *dpll)
1083 {
1084 	struct dpll_device_registration *reg;
1085 
1086 	reg = list_first_entry_or_null((struct list_head *)&dpll->registration_list,
1087 				       struct dpll_device_registration, list);
1088 	WARN_ON(!reg);
1089 	return reg;
1090 }
1091 
1092 void *dpll_priv(struct dpll_device *dpll)
1093 {
1094 	struct dpll_device_registration *reg;
1095 
1096 	reg = dpll_device_registration_first(dpll);
1097 	return reg->priv;
1098 }
1099 
1100 const struct dpll_device_ops *dpll_device_ops(struct dpll_device *dpll)
1101 {
1102 	struct dpll_device_registration *reg;
1103 
1104 	reg = dpll_device_registration_first(dpll);
1105 	return reg->ops;
1106 }
1107 
1108 static struct dpll_pin_registration *
1109 dpll_pin_registration_first(struct dpll_pin_ref *ref)
1110 {
1111 	struct dpll_pin_registration *reg;
1112 
1113 	reg = list_first_entry_or_null(&ref->registration_list,
1114 				       struct dpll_pin_registration, list);
1115 	WARN_ON(!reg);
1116 	return reg;
1117 }
1118 
1119 void *dpll_pin_on_dpll_priv(struct dpll_device *dpll,
1120 			    struct dpll_pin *pin)
1121 {
1122 	struct dpll_pin_registration *reg;
1123 	struct dpll_pin_ref *ref;
1124 
1125 	ref = xa_load(&dpll->pin_refs, pin->pin_idx);
1126 	if (!ref)
1127 		return NULL;
1128 	reg = dpll_pin_registration_first(ref);
1129 	return reg->priv;
1130 }
1131 
1132 void *dpll_pin_on_pin_priv(struct dpll_pin *parent,
1133 			   struct dpll_pin *pin)
1134 {
1135 	struct dpll_pin_registration *reg;
1136 	struct dpll_pin_ref *ref;
1137 
1138 	ref = xa_load(&pin->parent_refs, parent->pin_idx);
1139 	if (!ref)
1140 		return NULL;
1141 	reg = dpll_pin_registration_first(ref);
1142 	return reg->priv;
1143 }
1144 
1145 const struct dpll_pin_ops *dpll_pin_ops(struct dpll_pin_ref *ref)
1146 {
1147 	struct dpll_pin_registration *reg;
1148 
1149 	reg = dpll_pin_registration_first(ref);
1150 	return reg->ops;
1151 }
1152 
1153 static int __init dpll_init(void)
1154 {
1155 	int ret;
1156 
1157 	ret = genl_register_family(&dpll_nl_family);
1158 	if (ret)
1159 		goto error;
1160 
1161 	return 0;
1162 
1163 error:
1164 	mutex_destroy(&dpll_lock);
1165 	return ret;
1166 }
1167 
1168 static void __exit dpll_exit(void)
1169 {
1170 	genl_unregister_family(&dpll_nl_family);
1171 	mutex_destroy(&dpll_lock);
1172 }
1173 
1174 subsys_initcall(dpll_init);
1175 module_exit(dpll_exit);
1176