xref: /linux/drivers/net/pse-pd/pse_core.c (revision 4640a1f0d8f2246f34d6e74330d7e7d2cf75605b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 //
3 // Framework for Ethernet Power Sourcing Equipment
4 //
5 // Copyright (c) 2022 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
6 //
7 
8 #include <linux/device.h>
9 #include <linux/of.h>
10 #include <linux/pse-pd/pse.h>
11 #include <linux/regulator/driver.h>
12 #include <linux/regulator/machine.h>
13 
14 static DEFINE_MUTEX(pse_list_mutex);
15 static LIST_HEAD(pse_controller_list);
16 
17 /**
18  * struct pse_control - a PSE control
19  * @pcdev: a pointer to the PSE controller device
20  *         this PSE control belongs to
21  * @ps: PSE PI supply of the PSE control
22  * @list: list entry for the pcdev's PSE controller list
23  * @id: ID of the PSE line in the PSE controller device
24  * @refcnt: Number of gets of this pse_control
25  */
26 struct pse_control {
27 	struct pse_controller_dev *pcdev;
28 	struct regulator *ps;
29 	struct list_head list;
30 	unsigned int id;
31 	struct kref refcnt;
32 };
33 
34 static int of_load_single_pse_pi_pairset(struct device_node *node,
35 					 struct pse_pi *pi,
36 					 int pairset_num)
37 {
38 	struct device_node *pairset_np;
39 	const char *name;
40 	int ret;
41 
42 	ret = of_property_read_string_index(node, "pairset-names",
43 					    pairset_num, &name);
44 	if (ret)
45 		return ret;
46 
47 	if (!strcmp(name, "alternative-a")) {
48 		pi->pairset[pairset_num].pinout = ALTERNATIVE_A;
49 	} else if (!strcmp(name, "alternative-b")) {
50 		pi->pairset[pairset_num].pinout = ALTERNATIVE_B;
51 	} else {
52 		pr_err("pse: wrong pairset-names value %s (%pOF)\n",
53 		       name, node);
54 		return -EINVAL;
55 	}
56 
57 	pairset_np = of_parse_phandle(node, "pairsets", pairset_num);
58 	if (!pairset_np)
59 		return -ENODEV;
60 
61 	pi->pairset[pairset_num].np = pairset_np;
62 
63 	return 0;
64 }
65 
66 /**
67  * of_load_pse_pi_pairsets - load PSE PI pairsets pinout and polarity
68  * @node: a pointer of the device node
69  * @pi: a pointer of the PSE PI to fill
70  * @npairsets: the number of pairsets (1 or 2) used by the PI
71  *
72  * Return: 0 on success and failure value on error
73  */
74 static int of_load_pse_pi_pairsets(struct device_node *node,
75 				   struct pse_pi *pi,
76 				   int npairsets)
77 {
78 	int i, ret;
79 
80 	ret = of_property_count_strings(node, "pairset-names");
81 	if (ret != npairsets) {
82 		pr_err("pse: amount of pairsets and pairset-names is not equal %d != %d (%pOF)\n",
83 		       npairsets, ret, node);
84 		return -EINVAL;
85 	}
86 
87 	for (i = 0; i < npairsets; i++) {
88 		ret = of_load_single_pse_pi_pairset(node, pi, i);
89 		if (ret)
90 			goto out;
91 	}
92 
93 	if (npairsets == 2 &&
94 	    pi->pairset[0].pinout == pi->pairset[1].pinout) {
95 		pr_err("pse: two PI pairsets can not have identical pinout (%pOF)",
96 		       node);
97 		ret = -EINVAL;
98 	}
99 
100 out:
101 	/* If an error appears, release all the pairset device node kref */
102 	if (ret) {
103 		of_node_put(pi->pairset[0].np);
104 		pi->pairset[0].np = NULL;
105 		of_node_put(pi->pairset[1].np);
106 		pi->pairset[1].np = NULL;
107 	}
108 
109 	return ret;
110 }
111 
112 static void pse_release_pis(struct pse_controller_dev *pcdev)
113 {
114 	int i;
115 
116 	for (i = 0; i < pcdev->nr_lines; i++) {
117 		of_node_put(pcdev->pi[i].pairset[0].np);
118 		of_node_put(pcdev->pi[i].pairset[1].np);
119 		of_node_put(pcdev->pi[i].np);
120 	}
121 	kfree(pcdev->pi);
122 }
123 
124 /**
125  * of_load_pse_pis - load all the PSE PIs
126  * @pcdev: a pointer to the PSE controller device
127  *
128  * Return: 0 on success and failure value on error
129  */
130 static int of_load_pse_pis(struct pse_controller_dev *pcdev)
131 {
132 	struct device_node *np = pcdev->dev->of_node;
133 	struct device_node *node, *pis;
134 	int ret;
135 
136 	if (!np)
137 		return -ENODEV;
138 
139 	pcdev->pi = kcalloc(pcdev->nr_lines, sizeof(*pcdev->pi), GFP_KERNEL);
140 	if (!pcdev->pi)
141 		return -ENOMEM;
142 
143 	pis = of_get_child_by_name(np, "pse-pis");
144 	if (!pis) {
145 		/* no description of PSE PIs */
146 		pcdev->no_of_pse_pi = true;
147 		return 0;
148 	}
149 
150 	for_each_child_of_node(pis, node) {
151 		struct pse_pi pi = {0};
152 		u32 id;
153 
154 		if (!of_node_name_eq(node, "pse-pi"))
155 			continue;
156 
157 		ret = of_property_read_u32(node, "reg", &id);
158 		if (ret) {
159 			dev_err(pcdev->dev,
160 				"can't get reg property for node '%pOF'",
161 				node);
162 			goto out;
163 		}
164 
165 		if (id >= pcdev->nr_lines) {
166 			dev_err(pcdev->dev,
167 				"reg value (%u) is out of range (%u) (%pOF)\n",
168 				id, pcdev->nr_lines, node);
169 			ret = -EINVAL;
170 			goto out;
171 		}
172 
173 		if (pcdev->pi[id].np) {
174 			dev_err(pcdev->dev,
175 				"other node with same reg value was already registered. %pOF : %pOF\n",
176 				pcdev->pi[id].np, node);
177 			ret = -EINVAL;
178 			goto out;
179 		}
180 
181 		ret = of_count_phandle_with_args(node, "pairsets", NULL);
182 		/* npairsets is limited to value one or two */
183 		if (ret == 1 || ret == 2) {
184 			ret = of_load_pse_pi_pairsets(node, &pi, ret);
185 			if (ret)
186 				goto out;
187 		} else if (ret != ENOENT) {
188 			dev_err(pcdev->dev,
189 				"error: wrong number of pairsets. Should be 1 or 2, got %d (%pOF)\n",
190 				ret, node);
191 			ret = -EINVAL;
192 			goto out;
193 		}
194 
195 		of_node_get(node);
196 		pi.np = node;
197 		memcpy(&pcdev->pi[id], &pi, sizeof(pi));
198 	}
199 
200 	of_node_put(pis);
201 	return 0;
202 
203 out:
204 	pse_release_pis(pcdev);
205 	of_node_put(node);
206 	of_node_put(pis);
207 	return ret;
208 }
209 
210 static int pse_pi_is_enabled(struct regulator_dev *rdev)
211 {
212 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
213 	struct pse_admin_state admin_state = {0};
214 	const struct pse_controller_ops *ops;
215 	int id, ret;
216 
217 	ops = pcdev->ops;
218 	if (!ops->pi_get_admin_state)
219 		return -EOPNOTSUPP;
220 
221 	id = rdev_get_id(rdev);
222 	mutex_lock(&pcdev->lock);
223 	ret = ops->pi_get_admin_state(pcdev, id, &admin_state);
224 	if (ret)
225 		goto out;
226 
227 	if (admin_state.podl_admin_state == ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED ||
228 	    admin_state.c33_admin_state == ETHTOOL_C33_PSE_ADMIN_STATE_ENABLED)
229 		ret = 1;
230 
231 out:
232 	mutex_unlock(&pcdev->lock);
233 
234 	return ret;
235 }
236 
237 static int pse_pi_enable(struct regulator_dev *rdev)
238 {
239 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
240 	const struct pse_controller_ops *ops;
241 	int id, ret;
242 
243 	ops = pcdev->ops;
244 	if (!ops->pi_enable)
245 		return -EOPNOTSUPP;
246 
247 	id = rdev_get_id(rdev);
248 	mutex_lock(&pcdev->lock);
249 	ret = ops->pi_enable(pcdev, id);
250 	if (!ret)
251 		pcdev->pi[id].admin_state_enabled = 1;
252 	mutex_unlock(&pcdev->lock);
253 
254 	return ret;
255 }
256 
257 static int pse_pi_disable(struct regulator_dev *rdev)
258 {
259 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
260 	const struct pse_controller_ops *ops;
261 	int id, ret;
262 
263 	ops = pcdev->ops;
264 	if (!ops->pi_disable)
265 		return -EOPNOTSUPP;
266 
267 	id = rdev_get_id(rdev);
268 	mutex_lock(&pcdev->lock);
269 	ret = ops->pi_disable(pcdev, id);
270 	if (!ret)
271 		pcdev->pi[id].admin_state_enabled = 0;
272 	mutex_unlock(&pcdev->lock);
273 
274 	return ret;
275 }
276 
277 static int _pse_pi_get_voltage(struct regulator_dev *rdev)
278 {
279 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
280 	const struct pse_controller_ops *ops;
281 	int id;
282 
283 	ops = pcdev->ops;
284 	if (!ops->pi_get_voltage)
285 		return -EOPNOTSUPP;
286 
287 	id = rdev_get_id(rdev);
288 	return ops->pi_get_voltage(pcdev, id);
289 }
290 
291 static int pse_pi_get_voltage(struct regulator_dev *rdev)
292 {
293 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
294 	int ret;
295 
296 	mutex_lock(&pcdev->lock);
297 	ret = _pse_pi_get_voltage(rdev);
298 	mutex_unlock(&pcdev->lock);
299 
300 	return ret;
301 }
302 
303 static int pse_pi_get_current_limit(struct regulator_dev *rdev)
304 {
305 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
306 	const struct pse_controller_ops *ops;
307 	int id, uV, mW, ret;
308 	s64 tmp_64;
309 
310 	ops = pcdev->ops;
311 	id = rdev_get_id(rdev);
312 	if (!ops->pi_get_pw_limit || !ops->pi_get_voltage)
313 		return -EOPNOTSUPP;
314 
315 	mutex_lock(&pcdev->lock);
316 	ret = ops->pi_get_pw_limit(pcdev, id);
317 	if (ret < 0)
318 		goto out;
319 	mW = ret;
320 
321 	ret = pse_pi_get_voltage(rdev);
322 	if (!ret) {
323 		dev_err(pcdev->dev, "Voltage null\n");
324 		ret = -ERANGE;
325 		goto out;
326 	}
327 	if (ret < 0)
328 		goto out;
329 	uV = ret;
330 
331 	tmp_64 = mW;
332 	tmp_64 *= 1000000000ull;
333 	/* uA = mW * 1000000000 / uV */
334 	ret = DIV_ROUND_CLOSEST_ULL(tmp_64, uV);
335 
336 out:
337 	mutex_unlock(&pcdev->lock);
338 	return ret;
339 }
340 
341 static int pse_pi_set_current_limit(struct regulator_dev *rdev, int min_uA,
342 				    int max_uA)
343 {
344 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
345 	const struct pse_controller_ops *ops;
346 	int id, mW, ret;
347 	s64 tmp_64;
348 
349 	ops = pcdev->ops;
350 	if (!ops->pi_set_pw_limit || !ops->pi_get_voltage)
351 		return -EOPNOTSUPP;
352 
353 	if (max_uA > MAX_PI_CURRENT)
354 		return -ERANGE;
355 
356 	id = rdev_get_id(rdev);
357 	mutex_lock(&pcdev->lock);
358 	ret = pse_pi_get_voltage(rdev);
359 	if (!ret) {
360 		dev_err(pcdev->dev, "Voltage null\n");
361 		ret = -ERANGE;
362 		goto out;
363 	}
364 	if (ret < 0)
365 		goto out;
366 
367 	tmp_64 = ret;
368 	tmp_64 *= max_uA;
369 	/* mW = uA * uV / 1000000000 */
370 	mW = DIV_ROUND_CLOSEST_ULL(tmp_64, 1000000000);
371 	ret = ops->pi_set_pw_limit(pcdev, id, mW);
372 out:
373 	mutex_unlock(&pcdev->lock);
374 
375 	return ret;
376 }
377 
378 static const struct regulator_ops pse_pi_ops = {
379 	.is_enabled = pse_pi_is_enabled,
380 	.enable = pse_pi_enable,
381 	.disable = pse_pi_disable,
382 	.get_voltage = pse_pi_get_voltage,
383 	.get_current_limit = pse_pi_get_current_limit,
384 	.set_current_limit = pse_pi_set_current_limit,
385 };
386 
387 static int
388 devm_pse_pi_regulator_register(struct pse_controller_dev *pcdev,
389 			       char *name, int id)
390 {
391 	struct regulator_init_data *rinit_data;
392 	struct regulator_config rconfig = {0};
393 	struct regulator_desc *rdesc;
394 	struct regulator_dev *rdev;
395 
396 	rinit_data = devm_kzalloc(pcdev->dev, sizeof(*rinit_data),
397 				  GFP_KERNEL);
398 	if (!rinit_data)
399 		return -ENOMEM;
400 
401 	rdesc = devm_kzalloc(pcdev->dev, sizeof(*rdesc), GFP_KERNEL);
402 	if (!rdesc)
403 		return -ENOMEM;
404 
405 	/* Regulator descriptor id have to be the same as its associated
406 	 * PSE PI id for the well functioning of the PSE controls.
407 	 */
408 	rdesc->id = id;
409 	rdesc->name = name;
410 	rdesc->type = REGULATOR_VOLTAGE;
411 	rdesc->ops = &pse_pi_ops;
412 	rdesc->owner = pcdev->owner;
413 
414 	rinit_data->constraints.valid_ops_mask = REGULATOR_CHANGE_STATUS;
415 
416 	if (pcdev->ops->pi_set_pw_limit)
417 		rinit_data->constraints.valid_ops_mask |=
418 			REGULATOR_CHANGE_CURRENT;
419 
420 	rinit_data->supply_regulator = "vpwr";
421 
422 	rconfig.dev = pcdev->dev;
423 	rconfig.driver_data = pcdev;
424 	rconfig.init_data = rinit_data;
425 
426 	rdev = devm_regulator_register(pcdev->dev, rdesc, &rconfig);
427 	if (IS_ERR(rdev)) {
428 		dev_err_probe(pcdev->dev, PTR_ERR(rdev),
429 			      "Failed to register regulator\n");
430 		return PTR_ERR(rdev);
431 	}
432 
433 	pcdev->pi[id].rdev = rdev;
434 
435 	return 0;
436 }
437 
438 /**
439  * pse_controller_register - register a PSE controller device
440  * @pcdev: a pointer to the initialized PSE controller device
441  *
442  * Return: 0 on success and failure value on error
443  */
444 int pse_controller_register(struct pse_controller_dev *pcdev)
445 {
446 	size_t reg_name_len;
447 	int ret, i;
448 
449 	mutex_init(&pcdev->lock);
450 	INIT_LIST_HEAD(&pcdev->pse_control_head);
451 
452 	if (!pcdev->nr_lines)
453 		pcdev->nr_lines = 1;
454 
455 	if (!pcdev->ops->pi_get_admin_state ||
456 	    !pcdev->ops->pi_get_pw_status) {
457 		dev_err(pcdev->dev,
458 			"Mandatory status report callbacks are missing");
459 		return -EINVAL;
460 	}
461 
462 	ret = of_load_pse_pis(pcdev);
463 	if (ret)
464 		return ret;
465 
466 	if (pcdev->ops->setup_pi_matrix) {
467 		ret = pcdev->ops->setup_pi_matrix(pcdev);
468 		if (ret)
469 			return ret;
470 	}
471 
472 	/* Each regulator name len is pcdev dev name + 7 char +
473 	 * int max digit number (10) + 1
474 	 */
475 	reg_name_len = strlen(dev_name(pcdev->dev)) + 18;
476 
477 	/* Register PI regulators */
478 	for (i = 0; i < pcdev->nr_lines; i++) {
479 		char *reg_name;
480 
481 		/* Do not register regulator for PIs not described */
482 		if (!pcdev->no_of_pse_pi && !pcdev->pi[i].np)
483 			continue;
484 
485 		reg_name = devm_kzalloc(pcdev->dev, reg_name_len, GFP_KERNEL);
486 		if (!reg_name)
487 			return -ENOMEM;
488 
489 		snprintf(reg_name, reg_name_len, "pse-%s_pi%d",
490 			 dev_name(pcdev->dev), i);
491 
492 		ret = devm_pse_pi_regulator_register(pcdev, reg_name, i);
493 		if (ret)
494 			return ret;
495 	}
496 
497 	mutex_lock(&pse_list_mutex);
498 	list_add(&pcdev->list, &pse_controller_list);
499 	mutex_unlock(&pse_list_mutex);
500 
501 	return 0;
502 }
503 EXPORT_SYMBOL_GPL(pse_controller_register);
504 
505 /**
506  * pse_controller_unregister - unregister a PSE controller device
507  * @pcdev: a pointer to the PSE controller device
508  */
509 void pse_controller_unregister(struct pse_controller_dev *pcdev)
510 {
511 	pse_release_pis(pcdev);
512 	mutex_lock(&pse_list_mutex);
513 	list_del(&pcdev->list);
514 	mutex_unlock(&pse_list_mutex);
515 }
516 EXPORT_SYMBOL_GPL(pse_controller_unregister);
517 
518 static void devm_pse_controller_release(struct device *dev, void *res)
519 {
520 	pse_controller_unregister(*(struct pse_controller_dev **)res);
521 }
522 
523 /**
524  * devm_pse_controller_register - resource managed pse_controller_register()
525  * @dev: device that is registering this PSE controller
526  * @pcdev: a pointer to the initialized PSE controller device
527  *
528  * Managed pse_controller_register(). For PSE controllers registered by
529  * this function, pse_controller_unregister() is automatically called on
530  * driver detach. See pse_controller_register() for more information.
531  *
532  * Return: 0 on success and failure value on error
533  */
534 int devm_pse_controller_register(struct device *dev,
535 				 struct pse_controller_dev *pcdev)
536 {
537 	struct pse_controller_dev **pcdevp;
538 	int ret;
539 
540 	pcdevp = devres_alloc(devm_pse_controller_release, sizeof(*pcdevp),
541 			      GFP_KERNEL);
542 	if (!pcdevp)
543 		return -ENOMEM;
544 
545 	ret = pse_controller_register(pcdev);
546 	if (ret) {
547 		devres_free(pcdevp);
548 		return ret;
549 	}
550 
551 	*pcdevp = pcdev;
552 	devres_add(dev, pcdevp);
553 
554 	return 0;
555 }
556 EXPORT_SYMBOL_GPL(devm_pse_controller_register);
557 
558 /* PSE control section */
559 
560 static void __pse_control_release(struct kref *kref)
561 {
562 	struct pse_control *psec = container_of(kref, struct pse_control,
563 						  refcnt);
564 
565 	lockdep_assert_held(&pse_list_mutex);
566 
567 	if (psec->pcdev->pi[psec->id].admin_state_enabled)
568 		regulator_disable(psec->ps);
569 	devm_regulator_put(psec->ps);
570 
571 	module_put(psec->pcdev->owner);
572 
573 	list_del(&psec->list);
574 	kfree(psec);
575 }
576 
577 static void __pse_control_put_internal(struct pse_control *psec)
578 {
579 	lockdep_assert_held(&pse_list_mutex);
580 
581 	kref_put(&psec->refcnt, __pse_control_release);
582 }
583 
584 /**
585  * pse_control_put - free the PSE control
586  * @psec: PSE control pointer
587  */
588 void pse_control_put(struct pse_control *psec)
589 {
590 	if (IS_ERR_OR_NULL(psec))
591 		return;
592 
593 	mutex_lock(&pse_list_mutex);
594 	__pse_control_put_internal(psec);
595 	mutex_unlock(&pse_list_mutex);
596 }
597 EXPORT_SYMBOL_GPL(pse_control_put);
598 
599 static struct pse_control *
600 pse_control_get_internal(struct pse_controller_dev *pcdev, unsigned int index)
601 {
602 	struct pse_control *psec;
603 	int ret;
604 
605 	lockdep_assert_held(&pse_list_mutex);
606 
607 	list_for_each_entry(psec, &pcdev->pse_control_head, list) {
608 		if (psec->id == index) {
609 			kref_get(&psec->refcnt);
610 			return psec;
611 		}
612 	}
613 
614 	psec = kzalloc(sizeof(*psec), GFP_KERNEL);
615 	if (!psec)
616 		return ERR_PTR(-ENOMEM);
617 
618 	if (!try_module_get(pcdev->owner)) {
619 		ret = -ENODEV;
620 		goto free_psec;
621 	}
622 
623 	psec->ps = devm_regulator_get_exclusive(pcdev->dev,
624 						rdev_get_name(pcdev->pi[index].rdev));
625 	if (IS_ERR(psec->ps)) {
626 		ret = PTR_ERR(psec->ps);
627 		goto put_module;
628 	}
629 
630 	ret = regulator_is_enabled(psec->ps);
631 	if (ret < 0)
632 		goto regulator_put;
633 
634 	pcdev->pi[index].admin_state_enabled = ret;
635 
636 	psec->pcdev = pcdev;
637 	list_add(&psec->list, &pcdev->pse_control_head);
638 	psec->id = index;
639 	kref_init(&psec->refcnt);
640 
641 	return psec;
642 
643 regulator_put:
644 	devm_regulator_put(psec->ps);
645 put_module:
646 	module_put(pcdev->owner);
647 free_psec:
648 	kfree(psec);
649 
650 	return ERR_PTR(ret);
651 }
652 
653 /**
654  * of_pse_match_pi - Find the PSE PI id matching the device node phandle
655  * @pcdev: a pointer to the PSE controller device
656  * @np: a pointer to the device node
657  *
658  * Return: id of the PSE PI, -EINVAL if not found
659  */
660 static int of_pse_match_pi(struct pse_controller_dev *pcdev,
661 			   struct device_node *np)
662 {
663 	int i;
664 
665 	for (i = 0; i < pcdev->nr_lines; i++) {
666 		if (pcdev->pi[i].np == np)
667 			return i;
668 	}
669 
670 	return -EINVAL;
671 }
672 
673 /**
674  * psec_id_xlate - translate pse_spec to the PSE line number according
675  *		   to the number of pse-cells in case of no pse_pi node
676  * @pcdev: a pointer to the PSE controller device
677  * @pse_spec: PSE line specifier as found in the device tree
678  *
679  * Return: 0 if #pse-cells = <0>. Return PSE line number otherwise.
680  */
681 static int psec_id_xlate(struct pse_controller_dev *pcdev,
682 			 const struct of_phandle_args *pse_spec)
683 {
684 	if (!pcdev->of_pse_n_cells)
685 		return 0;
686 
687 	if (pcdev->of_pse_n_cells > 1 ||
688 	    pse_spec->args[0] >= pcdev->nr_lines)
689 		return -EINVAL;
690 
691 	return pse_spec->args[0];
692 }
693 
694 struct pse_control *of_pse_control_get(struct device_node *node)
695 {
696 	struct pse_controller_dev *r, *pcdev;
697 	struct of_phandle_args args;
698 	struct pse_control *psec;
699 	int psec_id;
700 	int ret;
701 
702 	if (!node)
703 		return ERR_PTR(-EINVAL);
704 
705 	ret = of_parse_phandle_with_args(node, "pses", "#pse-cells", 0, &args);
706 	if (ret)
707 		return ERR_PTR(ret);
708 
709 	mutex_lock(&pse_list_mutex);
710 	pcdev = NULL;
711 	list_for_each_entry(r, &pse_controller_list, list) {
712 		if (!r->no_of_pse_pi) {
713 			ret = of_pse_match_pi(r, args.np);
714 			if (ret >= 0) {
715 				pcdev = r;
716 				psec_id = ret;
717 				break;
718 			}
719 		} else if (args.np == r->dev->of_node) {
720 			pcdev = r;
721 			break;
722 		}
723 	}
724 
725 	if (!pcdev) {
726 		psec = ERR_PTR(-EPROBE_DEFER);
727 		goto out;
728 	}
729 
730 	if (WARN_ON(args.args_count != pcdev->of_pse_n_cells)) {
731 		psec = ERR_PTR(-EINVAL);
732 		goto out;
733 	}
734 
735 	if (pcdev->no_of_pse_pi) {
736 		psec_id = psec_id_xlate(pcdev, &args);
737 		if (psec_id < 0) {
738 			psec = ERR_PTR(psec_id);
739 			goto out;
740 		}
741 	}
742 
743 	/* pse_list_mutex also protects the pcdev's pse_control list */
744 	psec = pse_control_get_internal(pcdev, psec_id);
745 
746 out:
747 	mutex_unlock(&pse_list_mutex);
748 	of_node_put(args.np);
749 
750 	return psec;
751 }
752 EXPORT_SYMBOL_GPL(of_pse_control_get);
753 
754 /**
755  * pse_ethtool_get_status - get status of PSE control
756  * @psec: PSE control pointer
757  * @extack: extack for reporting useful error messages
758  * @status: struct to store PSE status
759  *
760  * Return: 0 on success and failure value on error
761  */
762 int pse_ethtool_get_status(struct pse_control *psec,
763 			   struct netlink_ext_ack *extack,
764 			   struct ethtool_pse_control_status *status)
765 {
766 	struct pse_admin_state admin_state = {0};
767 	struct pse_pw_status pw_status = {0};
768 	const struct pse_controller_ops *ops;
769 	struct pse_controller_dev *pcdev;
770 	int ret;
771 
772 	pcdev = psec->pcdev;
773 	ops = pcdev->ops;
774 	mutex_lock(&pcdev->lock);
775 	ret = ops->pi_get_admin_state(pcdev, psec->id, &admin_state);
776 	if (ret)
777 		goto out;
778 	status->podl_admin_state = admin_state.podl_admin_state;
779 	status->c33_admin_state = admin_state.c33_admin_state;
780 
781 	ret = ops->pi_get_pw_status(pcdev, psec->id, &pw_status);
782 	if (ret)
783 		goto out;
784 	status->podl_pw_status = pw_status.podl_pw_status;
785 	status->c33_pw_status = pw_status.c33_pw_status;
786 
787 	if (ops->pi_get_ext_state) {
788 		struct pse_ext_state_info ext_state_info = {0};
789 
790 		ret = ops->pi_get_ext_state(pcdev, psec->id,
791 					    &ext_state_info);
792 		if (ret)
793 			goto out;
794 
795 		memcpy(&status->c33_ext_state_info,
796 		       &ext_state_info.c33_ext_state_info,
797 		       sizeof(status->c33_ext_state_info));
798 	}
799 
800 	if (ops->pi_get_pw_class) {
801 		ret = ops->pi_get_pw_class(pcdev, psec->id);
802 		if (ret < 0)
803 			goto out;
804 
805 		status->c33_pw_class = ret;
806 	}
807 
808 	if (ops->pi_get_actual_pw) {
809 		ret = ops->pi_get_actual_pw(pcdev, psec->id);
810 		if (ret < 0)
811 			goto out;
812 
813 		status->c33_actual_pw = ret;
814 	}
815 
816 	if (ops->pi_get_pw_limit) {
817 		ret = ops->pi_get_pw_limit(pcdev, psec->id);
818 		if (ret < 0)
819 			goto out;
820 
821 		status->c33_avail_pw_limit = ret;
822 	}
823 
824 	if (ops->pi_get_pw_limit_ranges) {
825 		struct pse_pw_limit_ranges pw_limit_ranges = {0};
826 
827 		ret = ops->pi_get_pw_limit_ranges(pcdev, psec->id,
828 						  &pw_limit_ranges);
829 		if (ret < 0)
830 			goto out;
831 
832 		status->c33_pw_limit_ranges =
833 			pw_limit_ranges.c33_pw_limit_ranges;
834 		status->c33_pw_limit_nb_ranges = ret;
835 	}
836 out:
837 	mutex_unlock(&psec->pcdev->lock);
838 	return ret;
839 }
840 EXPORT_SYMBOL_GPL(pse_ethtool_get_status);
841 
842 static int pse_ethtool_c33_set_config(struct pse_control *psec,
843 				      const struct pse_control_config *config)
844 {
845 	int err = 0;
846 
847 	/* Look at admin_state_enabled status to not call regulator_enable
848 	 * or regulator_disable twice creating a regulator counter mismatch
849 	 */
850 	switch (config->c33_admin_control) {
851 	case ETHTOOL_C33_PSE_ADMIN_STATE_ENABLED:
852 		/* We could have mismatch between admin_state_enabled and
853 		 * state reported by regulator_is_enabled. This can occur when
854 		 * the PI is forcibly turn off by the controller. Call
855 		 * regulator_disable on that case to fix the counters state.
856 		 */
857 		if (psec->pcdev->pi[psec->id].admin_state_enabled &&
858 		    !regulator_is_enabled(psec->ps)) {
859 			err = regulator_disable(psec->ps);
860 			if (err)
861 				break;
862 		}
863 		if (!psec->pcdev->pi[psec->id].admin_state_enabled)
864 			err = regulator_enable(psec->ps);
865 		break;
866 	case ETHTOOL_C33_PSE_ADMIN_STATE_DISABLED:
867 		if (psec->pcdev->pi[psec->id].admin_state_enabled)
868 			err = regulator_disable(psec->ps);
869 		break;
870 	default:
871 		err = -EOPNOTSUPP;
872 	}
873 
874 	return err;
875 }
876 
877 static int pse_ethtool_podl_set_config(struct pse_control *psec,
878 				       const struct pse_control_config *config)
879 {
880 	int err = 0;
881 
882 	/* Look at admin_state_enabled status to not call regulator_enable
883 	 * or regulator_disable twice creating a regulator counter mismatch
884 	 */
885 	switch (config->podl_admin_control) {
886 	case ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED:
887 		if (!psec->pcdev->pi[psec->id].admin_state_enabled)
888 			err = regulator_enable(psec->ps);
889 		break;
890 	case ETHTOOL_PODL_PSE_ADMIN_STATE_DISABLED:
891 		if (psec->pcdev->pi[psec->id].admin_state_enabled)
892 			err = regulator_disable(psec->ps);
893 		break;
894 	default:
895 		err = -EOPNOTSUPP;
896 	}
897 
898 	return err;
899 }
900 
901 /**
902  * pse_ethtool_set_config - set PSE control configuration
903  * @psec: PSE control pointer
904  * @extack: extack for reporting useful error messages
905  * @config: Configuration of the test to run
906  *
907  * Return: 0 on success and failure value on error
908  */
909 int pse_ethtool_set_config(struct pse_control *psec,
910 			   struct netlink_ext_ack *extack,
911 			   const struct pse_control_config *config)
912 {
913 	int err = 0;
914 
915 	if (pse_has_c33(psec) && config->c33_admin_control) {
916 		err = pse_ethtool_c33_set_config(psec, config);
917 		if (err)
918 			return err;
919 	}
920 
921 	if (pse_has_podl(psec) && config->podl_admin_control)
922 		err = pse_ethtool_podl_set_config(psec, config);
923 
924 	return err;
925 }
926 EXPORT_SYMBOL_GPL(pse_ethtool_set_config);
927 
928 /**
929  * pse_ethtool_set_pw_limit - set PSE control power limit
930  * @psec: PSE control pointer
931  * @extack: extack for reporting useful error messages
932  * @pw_limit: power limit value in mW
933  *
934  * Return: 0 on success and failure value on error
935  */
936 int pse_ethtool_set_pw_limit(struct pse_control *psec,
937 			     struct netlink_ext_ack *extack,
938 			     const unsigned int pw_limit)
939 {
940 	int uV, uA, ret;
941 	s64 tmp_64;
942 
943 	if (pw_limit > MAX_PI_PW)
944 		return -ERANGE;
945 
946 	ret = regulator_get_voltage(psec->ps);
947 	if (!ret) {
948 		NL_SET_ERR_MSG(extack,
949 			       "Can't calculate the current, PSE voltage read is 0");
950 		return -ERANGE;
951 	}
952 	if (ret < 0) {
953 		NL_SET_ERR_MSG(extack,
954 			       "Error reading PSE voltage");
955 		return ret;
956 	}
957 	uV = ret;
958 
959 	tmp_64 = pw_limit;
960 	tmp_64 *= 1000000000ull;
961 	/* uA = mW * 1000000000 / uV */
962 	uA = DIV_ROUND_CLOSEST_ULL(tmp_64, uV);
963 
964 	return regulator_set_current_limit(psec->ps, 0, uA);
965 }
966 EXPORT_SYMBOL_GPL(pse_ethtool_set_pw_limit);
967 
968 bool pse_has_podl(struct pse_control *psec)
969 {
970 	return psec->pcdev->types & ETHTOOL_PSE_PODL;
971 }
972 EXPORT_SYMBOL_GPL(pse_has_podl);
973 
974 bool pse_has_c33(struct pse_control *psec)
975 {
976 	return psec->pcdev->types & ETHTOOL_PSE_C33;
977 }
978 EXPORT_SYMBOL_GPL(pse_has_c33);
979