xref: /linux/drivers/net/pse-pd/pse_core.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 	const struct pse_controller_ops *ops;
214 	int id, ret;
215 
216 	ops = pcdev->ops;
217 	if (!ops->pi_is_enabled)
218 		return -EOPNOTSUPP;
219 
220 	id = rdev_get_id(rdev);
221 	mutex_lock(&pcdev->lock);
222 	ret = ops->pi_is_enabled(pcdev, id);
223 	mutex_unlock(&pcdev->lock);
224 
225 	return ret;
226 }
227 
228 static int pse_pi_enable(struct regulator_dev *rdev)
229 {
230 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
231 	const struct pse_controller_ops *ops;
232 	int id, ret;
233 
234 	ops = pcdev->ops;
235 	if (!ops->pi_enable)
236 		return -EOPNOTSUPP;
237 
238 	id = rdev_get_id(rdev);
239 	mutex_lock(&pcdev->lock);
240 	ret = ops->pi_enable(pcdev, id);
241 	if (!ret)
242 		pcdev->pi[id].admin_state_enabled = 1;
243 	mutex_unlock(&pcdev->lock);
244 
245 	return ret;
246 }
247 
248 static int pse_pi_disable(struct regulator_dev *rdev)
249 {
250 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
251 	const struct pse_controller_ops *ops;
252 	int id, ret;
253 
254 	ops = pcdev->ops;
255 	if (!ops->pi_disable)
256 		return -EOPNOTSUPP;
257 
258 	id = rdev_get_id(rdev);
259 	mutex_lock(&pcdev->lock);
260 	ret = ops->pi_disable(pcdev, id);
261 	if (!ret)
262 		pcdev->pi[id].admin_state_enabled = 0;
263 	mutex_unlock(&pcdev->lock);
264 
265 	return ret;
266 }
267 
268 static int _pse_pi_get_voltage(struct regulator_dev *rdev)
269 {
270 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
271 	const struct pse_controller_ops *ops;
272 	int id;
273 
274 	ops = pcdev->ops;
275 	if (!ops->pi_get_voltage)
276 		return -EOPNOTSUPP;
277 
278 	id = rdev_get_id(rdev);
279 	return ops->pi_get_voltage(pcdev, id);
280 }
281 
282 static int pse_pi_get_voltage(struct regulator_dev *rdev)
283 {
284 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
285 	int ret;
286 
287 	mutex_lock(&pcdev->lock);
288 	ret = _pse_pi_get_voltage(rdev);
289 	mutex_unlock(&pcdev->lock);
290 
291 	return ret;
292 }
293 
294 static int _pse_ethtool_get_status(struct pse_controller_dev *pcdev,
295 				   int id,
296 				   struct netlink_ext_ack *extack,
297 				   struct pse_control_status *status);
298 
299 static int pse_pi_get_current_limit(struct regulator_dev *rdev)
300 {
301 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
302 	const struct pse_controller_ops *ops;
303 	struct netlink_ext_ack extack = {};
304 	struct pse_control_status st = {};
305 	int id, uV, ret;
306 	s64 tmp_64;
307 
308 	ops = pcdev->ops;
309 	id = rdev_get_id(rdev);
310 	mutex_lock(&pcdev->lock);
311 	if (ops->pi_get_current_limit) {
312 		ret = ops->pi_get_current_limit(pcdev, id);
313 		goto out;
314 	}
315 
316 	/* If pi_get_current_limit() callback not populated get voltage
317 	 * from pi_get_voltage() and power limit from ethtool_get_status()
318 	 *  to calculate current limit.
319 	 */
320 	ret = _pse_pi_get_voltage(rdev);
321 	if (!ret) {
322 		dev_err(pcdev->dev, "Voltage null\n");
323 		ret = -ERANGE;
324 		goto out;
325 	}
326 	if (ret < 0)
327 		goto out;
328 	uV = ret;
329 
330 	ret = _pse_ethtool_get_status(pcdev, id, &extack, &st);
331 	if (ret)
332 		goto out;
333 
334 	if (!st.c33_avail_pw_limit) {
335 		ret = -ENODATA;
336 		goto out;
337 	}
338 
339 	tmp_64 = st.c33_avail_pw_limit;
340 	tmp_64 *= 1000000000ull;
341 	/* uA = mW * 1000000000 / uV */
342 	ret = DIV_ROUND_CLOSEST_ULL(tmp_64, uV);
343 
344 out:
345 	mutex_unlock(&pcdev->lock);
346 	return ret;
347 }
348 
349 static int pse_pi_set_current_limit(struct regulator_dev *rdev, int min_uA,
350 				    int max_uA)
351 {
352 	struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev);
353 	const struct pse_controller_ops *ops;
354 	int id, ret;
355 
356 	ops = pcdev->ops;
357 	if (!ops->pi_set_current_limit)
358 		return -EOPNOTSUPP;
359 
360 	id = rdev_get_id(rdev);
361 	mutex_lock(&pcdev->lock);
362 	ret = ops->pi_set_current_limit(pcdev, id, max_uA);
363 	mutex_unlock(&pcdev->lock);
364 
365 	return ret;
366 }
367 
368 static const struct regulator_ops pse_pi_ops = {
369 	.is_enabled = pse_pi_is_enabled,
370 	.enable = pse_pi_enable,
371 	.disable = pse_pi_disable,
372 	.get_voltage = pse_pi_get_voltage,
373 	.get_current_limit = pse_pi_get_current_limit,
374 	.set_current_limit = pse_pi_set_current_limit,
375 };
376 
377 static int
378 devm_pse_pi_regulator_register(struct pse_controller_dev *pcdev,
379 			       char *name, int id)
380 {
381 	struct regulator_init_data *rinit_data;
382 	struct regulator_config rconfig = {0};
383 	struct regulator_desc *rdesc;
384 	struct regulator_dev *rdev;
385 
386 	rinit_data = devm_kzalloc(pcdev->dev, sizeof(*rinit_data),
387 				  GFP_KERNEL);
388 	if (!rinit_data)
389 		return -ENOMEM;
390 
391 	rdesc = devm_kzalloc(pcdev->dev, sizeof(*rdesc), GFP_KERNEL);
392 	if (!rdesc)
393 		return -ENOMEM;
394 
395 	/* Regulator descriptor id have to be the same as its associated
396 	 * PSE PI id for the well functioning of the PSE controls.
397 	 */
398 	rdesc->id = id;
399 	rdesc->name = name;
400 	rdesc->type = REGULATOR_VOLTAGE;
401 	rdesc->ops = &pse_pi_ops;
402 	rdesc->owner = pcdev->owner;
403 
404 	rinit_data->constraints.valid_ops_mask = REGULATOR_CHANGE_STATUS;
405 
406 	if (pcdev->ops->pi_set_current_limit) {
407 		rinit_data->constraints.valid_ops_mask |=
408 			REGULATOR_CHANGE_CURRENT;
409 		rinit_data->constraints.max_uA = MAX_PI_CURRENT;
410 	}
411 
412 	rinit_data->supply_regulator = "vpwr";
413 
414 	rconfig.dev = pcdev->dev;
415 	rconfig.driver_data = pcdev;
416 	rconfig.init_data = rinit_data;
417 
418 	rdev = devm_regulator_register(pcdev->dev, rdesc, &rconfig);
419 	if (IS_ERR(rdev)) {
420 		dev_err_probe(pcdev->dev, PTR_ERR(rdev),
421 			      "Failed to register regulator\n");
422 		return PTR_ERR(rdev);
423 	}
424 
425 	pcdev->pi[id].rdev = rdev;
426 
427 	return 0;
428 }
429 
430 /**
431  * pse_controller_register - register a PSE controller device
432  * @pcdev: a pointer to the initialized PSE controller device
433  *
434  * Return: 0 on success and failure value on error
435  */
436 int pse_controller_register(struct pse_controller_dev *pcdev)
437 {
438 	size_t reg_name_len;
439 	int ret, i;
440 
441 	mutex_init(&pcdev->lock);
442 	INIT_LIST_HEAD(&pcdev->pse_control_head);
443 
444 	if (!pcdev->nr_lines)
445 		pcdev->nr_lines = 1;
446 
447 	ret = of_load_pse_pis(pcdev);
448 	if (ret)
449 		return ret;
450 
451 	if (pcdev->ops->setup_pi_matrix) {
452 		ret = pcdev->ops->setup_pi_matrix(pcdev);
453 		if (ret)
454 			return ret;
455 	}
456 
457 	/* Each regulator name len is pcdev dev name + 7 char +
458 	 * int max digit number (10) + 1
459 	 */
460 	reg_name_len = strlen(dev_name(pcdev->dev)) + 18;
461 
462 	/* Register PI regulators */
463 	for (i = 0; i < pcdev->nr_lines; i++) {
464 		char *reg_name;
465 
466 		/* Do not register regulator for PIs not described */
467 		if (!pcdev->no_of_pse_pi && !pcdev->pi[i].np)
468 			continue;
469 
470 		reg_name = devm_kzalloc(pcdev->dev, reg_name_len, GFP_KERNEL);
471 		if (!reg_name)
472 			return -ENOMEM;
473 
474 		snprintf(reg_name, reg_name_len, "pse-%s_pi%d",
475 			 dev_name(pcdev->dev), i);
476 
477 		ret = devm_pse_pi_regulator_register(pcdev, reg_name, i);
478 		if (ret)
479 			return ret;
480 	}
481 
482 	mutex_lock(&pse_list_mutex);
483 	list_add(&pcdev->list, &pse_controller_list);
484 	mutex_unlock(&pse_list_mutex);
485 
486 	return 0;
487 }
488 EXPORT_SYMBOL_GPL(pse_controller_register);
489 
490 /**
491  * pse_controller_unregister - unregister a PSE controller device
492  * @pcdev: a pointer to the PSE controller device
493  */
494 void pse_controller_unregister(struct pse_controller_dev *pcdev)
495 {
496 	pse_release_pis(pcdev);
497 	mutex_lock(&pse_list_mutex);
498 	list_del(&pcdev->list);
499 	mutex_unlock(&pse_list_mutex);
500 }
501 EXPORT_SYMBOL_GPL(pse_controller_unregister);
502 
503 static void devm_pse_controller_release(struct device *dev, void *res)
504 {
505 	pse_controller_unregister(*(struct pse_controller_dev **)res);
506 }
507 
508 /**
509  * devm_pse_controller_register - resource managed pse_controller_register()
510  * @dev: device that is registering this PSE controller
511  * @pcdev: a pointer to the initialized PSE controller device
512  *
513  * Managed pse_controller_register(). For PSE controllers registered by
514  * this function, pse_controller_unregister() is automatically called on
515  * driver detach. See pse_controller_register() for more information.
516  *
517  * Return: 0 on success and failure value on error
518  */
519 int devm_pse_controller_register(struct device *dev,
520 				 struct pse_controller_dev *pcdev)
521 {
522 	struct pse_controller_dev **pcdevp;
523 	int ret;
524 
525 	pcdevp = devres_alloc(devm_pse_controller_release, sizeof(*pcdevp),
526 			      GFP_KERNEL);
527 	if (!pcdevp)
528 		return -ENOMEM;
529 
530 	ret = pse_controller_register(pcdev);
531 	if (ret) {
532 		devres_free(pcdevp);
533 		return ret;
534 	}
535 
536 	*pcdevp = pcdev;
537 	devres_add(dev, pcdevp);
538 
539 	return 0;
540 }
541 EXPORT_SYMBOL_GPL(devm_pse_controller_register);
542 
543 /* PSE control section */
544 
545 static void __pse_control_release(struct kref *kref)
546 {
547 	struct pse_control *psec = container_of(kref, struct pse_control,
548 						  refcnt);
549 
550 	lockdep_assert_held(&pse_list_mutex);
551 
552 	if (psec->pcdev->pi[psec->id].admin_state_enabled)
553 		regulator_disable(psec->ps);
554 	devm_regulator_put(psec->ps);
555 
556 	module_put(psec->pcdev->owner);
557 
558 	list_del(&psec->list);
559 	kfree(psec);
560 }
561 
562 static void __pse_control_put_internal(struct pse_control *psec)
563 {
564 	lockdep_assert_held(&pse_list_mutex);
565 
566 	kref_put(&psec->refcnt, __pse_control_release);
567 }
568 
569 /**
570  * pse_control_put - free the PSE control
571  * @psec: PSE control pointer
572  */
573 void pse_control_put(struct pse_control *psec)
574 {
575 	if (IS_ERR_OR_NULL(psec))
576 		return;
577 
578 	mutex_lock(&pse_list_mutex);
579 	__pse_control_put_internal(psec);
580 	mutex_unlock(&pse_list_mutex);
581 }
582 EXPORT_SYMBOL_GPL(pse_control_put);
583 
584 static struct pse_control *
585 pse_control_get_internal(struct pse_controller_dev *pcdev, unsigned int index)
586 {
587 	struct pse_control *psec;
588 	int ret;
589 
590 	lockdep_assert_held(&pse_list_mutex);
591 
592 	list_for_each_entry(psec, &pcdev->pse_control_head, list) {
593 		if (psec->id == index) {
594 			kref_get(&psec->refcnt);
595 			return psec;
596 		}
597 	}
598 
599 	psec = kzalloc(sizeof(*psec), GFP_KERNEL);
600 	if (!psec)
601 		return ERR_PTR(-ENOMEM);
602 
603 	if (!try_module_get(pcdev->owner)) {
604 		ret = -ENODEV;
605 		goto free_psec;
606 	}
607 
608 	psec->ps = devm_regulator_get_exclusive(pcdev->dev,
609 						rdev_get_name(pcdev->pi[index].rdev));
610 	if (IS_ERR(psec->ps)) {
611 		ret = PTR_ERR(psec->ps);
612 		goto put_module;
613 	}
614 
615 	ret = regulator_is_enabled(psec->ps);
616 	if (ret < 0)
617 		goto regulator_put;
618 
619 	pcdev->pi[index].admin_state_enabled = ret;
620 
621 	psec->pcdev = pcdev;
622 	list_add(&psec->list, &pcdev->pse_control_head);
623 	psec->id = index;
624 	kref_init(&psec->refcnt);
625 
626 	return psec;
627 
628 regulator_put:
629 	devm_regulator_put(psec->ps);
630 put_module:
631 	module_put(pcdev->owner);
632 free_psec:
633 	kfree(psec);
634 
635 	return ERR_PTR(ret);
636 }
637 
638 /**
639  * of_pse_match_pi - Find the PSE PI id matching the device node phandle
640  * @pcdev: a pointer to the PSE controller device
641  * @np: a pointer to the device node
642  *
643  * Return: id of the PSE PI, -EINVAL if not found
644  */
645 static int of_pse_match_pi(struct pse_controller_dev *pcdev,
646 			   struct device_node *np)
647 {
648 	int i;
649 
650 	for (i = 0; i < pcdev->nr_lines; i++) {
651 		if (pcdev->pi[i].np == np)
652 			return i;
653 	}
654 
655 	return -EINVAL;
656 }
657 
658 /**
659  * psec_id_xlate - translate pse_spec to the PSE line number according
660  *		   to the number of pse-cells in case of no pse_pi node
661  * @pcdev: a pointer to the PSE controller device
662  * @pse_spec: PSE line specifier as found in the device tree
663  *
664  * Return: 0 if #pse-cells = <0>. Return PSE line number otherwise.
665  */
666 static int psec_id_xlate(struct pse_controller_dev *pcdev,
667 			 const struct of_phandle_args *pse_spec)
668 {
669 	if (!pcdev->of_pse_n_cells)
670 		return 0;
671 
672 	if (pcdev->of_pse_n_cells > 1 ||
673 	    pse_spec->args[0] >= pcdev->nr_lines)
674 		return -EINVAL;
675 
676 	return pse_spec->args[0];
677 }
678 
679 struct pse_control *of_pse_control_get(struct device_node *node)
680 {
681 	struct pse_controller_dev *r, *pcdev;
682 	struct of_phandle_args args;
683 	struct pse_control *psec;
684 	int psec_id;
685 	int ret;
686 
687 	if (!node)
688 		return ERR_PTR(-EINVAL);
689 
690 	ret = of_parse_phandle_with_args(node, "pses", "#pse-cells", 0, &args);
691 	if (ret)
692 		return ERR_PTR(ret);
693 
694 	mutex_lock(&pse_list_mutex);
695 	pcdev = NULL;
696 	list_for_each_entry(r, &pse_controller_list, list) {
697 		if (!r->no_of_pse_pi) {
698 			ret = of_pse_match_pi(r, args.np);
699 			if (ret >= 0) {
700 				pcdev = r;
701 				psec_id = ret;
702 				break;
703 			}
704 		} else if (args.np == r->dev->of_node) {
705 			pcdev = r;
706 			break;
707 		}
708 	}
709 
710 	if (!pcdev) {
711 		psec = ERR_PTR(-EPROBE_DEFER);
712 		goto out;
713 	}
714 
715 	if (WARN_ON(args.args_count != pcdev->of_pse_n_cells)) {
716 		psec = ERR_PTR(-EINVAL);
717 		goto out;
718 	}
719 
720 	if (pcdev->no_of_pse_pi) {
721 		psec_id = psec_id_xlate(pcdev, &args);
722 		if (psec_id < 0) {
723 			psec = ERR_PTR(psec_id);
724 			goto out;
725 		}
726 	}
727 
728 	/* pse_list_mutex also protects the pcdev's pse_control list */
729 	psec = pse_control_get_internal(pcdev, psec_id);
730 
731 out:
732 	mutex_unlock(&pse_list_mutex);
733 	of_node_put(args.np);
734 
735 	return psec;
736 }
737 EXPORT_SYMBOL_GPL(of_pse_control_get);
738 
739 static int _pse_ethtool_get_status(struct pse_controller_dev *pcdev,
740 				   int id,
741 				   struct netlink_ext_ack *extack,
742 				   struct pse_control_status *status)
743 {
744 	const struct pse_controller_ops *ops;
745 
746 	ops = pcdev->ops;
747 	if (!ops->ethtool_get_status) {
748 		NL_SET_ERR_MSG(extack,
749 			       "PSE driver does not support status report");
750 		return -EOPNOTSUPP;
751 	}
752 
753 	return ops->ethtool_get_status(pcdev, id, extack, status);
754 }
755 
756 /**
757  * pse_ethtool_get_status - get status of PSE control
758  * @psec: PSE control pointer
759  * @extack: extack for reporting useful error messages
760  * @status: struct to store PSE status
761  *
762  * Return: 0 on success and failure value on error
763  */
764 int pse_ethtool_get_status(struct pse_control *psec,
765 			   struct netlink_ext_ack *extack,
766 			   struct pse_control_status *status)
767 {
768 	int err;
769 
770 	mutex_lock(&psec->pcdev->lock);
771 	err = _pse_ethtool_get_status(psec->pcdev, psec->id, extack, status);
772 	mutex_unlock(&psec->pcdev->lock);
773 
774 	return err;
775 }
776 EXPORT_SYMBOL_GPL(pse_ethtool_get_status);
777 
778 static int pse_ethtool_c33_set_config(struct pse_control *psec,
779 				      const struct pse_control_config *config)
780 {
781 	int err = 0;
782 
783 	/* Look at admin_state_enabled status to not call regulator_enable
784 	 * or regulator_disable twice creating a regulator counter mismatch
785 	 */
786 	switch (config->c33_admin_control) {
787 	case ETHTOOL_C33_PSE_ADMIN_STATE_ENABLED:
788 		/* We could have mismatch between admin_state_enabled and
789 		 * state reported by regulator_is_enabled. This can occur when
790 		 * the PI is forcibly turn off by the controller. Call
791 		 * regulator_disable on that case to fix the counters state.
792 		 */
793 		if (psec->pcdev->pi[psec->id].admin_state_enabled &&
794 		    !regulator_is_enabled(psec->ps)) {
795 			err = regulator_disable(psec->ps);
796 			if (err)
797 				break;
798 		}
799 		if (!psec->pcdev->pi[psec->id].admin_state_enabled)
800 			err = regulator_enable(psec->ps);
801 		break;
802 	case ETHTOOL_C33_PSE_ADMIN_STATE_DISABLED:
803 		if (psec->pcdev->pi[psec->id].admin_state_enabled)
804 			err = regulator_disable(psec->ps);
805 		break;
806 	default:
807 		err = -EOPNOTSUPP;
808 	}
809 
810 	return err;
811 }
812 
813 static int pse_ethtool_podl_set_config(struct pse_control *psec,
814 				       const struct pse_control_config *config)
815 {
816 	int err = 0;
817 
818 	/* Look at admin_state_enabled status to not call regulator_enable
819 	 * or regulator_disable twice creating a regulator counter mismatch
820 	 */
821 	switch (config->podl_admin_control) {
822 	case ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED:
823 		if (!psec->pcdev->pi[psec->id].admin_state_enabled)
824 			err = regulator_enable(psec->ps);
825 		break;
826 	case ETHTOOL_PODL_PSE_ADMIN_STATE_DISABLED:
827 		if (psec->pcdev->pi[psec->id].admin_state_enabled)
828 			err = regulator_disable(psec->ps);
829 		break;
830 	default:
831 		err = -EOPNOTSUPP;
832 	}
833 
834 	return err;
835 }
836 
837 /**
838  * pse_ethtool_set_config - set PSE control configuration
839  * @psec: PSE control pointer
840  * @extack: extack for reporting useful error messages
841  * @config: Configuration of the test to run
842  *
843  * Return: 0 on success and failure value on error
844  */
845 int pse_ethtool_set_config(struct pse_control *psec,
846 			   struct netlink_ext_ack *extack,
847 			   const struct pse_control_config *config)
848 {
849 	int err = 0;
850 
851 	if (pse_has_c33(psec) && config->c33_admin_control) {
852 		err = pse_ethtool_c33_set_config(psec, config);
853 		if (err)
854 			return err;
855 	}
856 
857 	if (pse_has_podl(psec) && config->podl_admin_control)
858 		err = pse_ethtool_podl_set_config(psec, config);
859 
860 	return err;
861 }
862 EXPORT_SYMBOL_GPL(pse_ethtool_set_config);
863 
864 /**
865  * pse_ethtool_set_pw_limit - set PSE control power limit
866  * @psec: PSE control pointer
867  * @extack: extack for reporting useful error messages
868  * @pw_limit: power limit value in mW
869  *
870  * Return: 0 on success and failure value on error
871  */
872 int pse_ethtool_set_pw_limit(struct pse_control *psec,
873 			     struct netlink_ext_ack *extack,
874 			     const unsigned int pw_limit)
875 {
876 	int uV, uA, ret;
877 	s64 tmp_64;
878 
879 	ret = regulator_get_voltage(psec->ps);
880 	if (!ret) {
881 		NL_SET_ERR_MSG(extack,
882 			       "Can't calculate the current, PSE voltage read is 0");
883 		return -ERANGE;
884 	}
885 	if (ret < 0) {
886 		NL_SET_ERR_MSG(extack,
887 			       "Error reading PSE voltage");
888 		return ret;
889 	}
890 	uV = ret;
891 
892 	tmp_64 = pw_limit;
893 	tmp_64 *= 1000000000ull;
894 	/* uA = mW * 1000000000 / uV */
895 	uA = DIV_ROUND_CLOSEST_ULL(tmp_64, uV);
896 
897 	return regulator_set_current_limit(psec->ps, 0, uA);
898 }
899 EXPORT_SYMBOL_GPL(pse_ethtool_set_pw_limit);
900 
901 bool pse_has_podl(struct pse_control *psec)
902 {
903 	return psec->pcdev->types & ETHTOOL_PSE_PODL;
904 }
905 EXPORT_SYMBOL_GPL(pse_has_podl);
906 
907 bool pse_has_c33(struct pse_control *psec)
908 {
909 	return psec->pcdev->types & ETHTOOL_PSE_C33;
910 }
911 EXPORT_SYMBOL_GPL(pse_has_c33);
912