1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OF helpers for regulator framework
4  *
5  * Copyright (C) 2011 Texas Instruments, Inc.
6  * Rajendra Nayak <rnayak@ti.com>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/of.h>
12 #include <linux/regulator/machine.h>
13 #include <linux/regulator/driver.h>
14 #include <linux/regulator/of_regulator.h>
15 
16 #include "internal.h"
17 
18 static const char *const regulator_states[PM_SUSPEND_MAX + 1] = {
19 	[PM_SUSPEND_STANDBY]	= "regulator-state-standby",
20 	[PM_SUSPEND_MEM]	= "regulator-state-mem",
21 	[PM_SUSPEND_MAX]	= "regulator-state-disk",
22 };
23 
24 static void fill_limit(int *limit, int val)
25 {
26 	if (val)
27 		if (val == 1)
28 			*limit = REGULATOR_NOTIF_LIMIT_ENABLE;
29 		else
30 			*limit = val;
31 	else
32 		*limit = REGULATOR_NOTIF_LIMIT_DISABLE;
33 }
34 
35 static void of_get_regulator_prot_limits(struct device_node *np,
36 				struct regulation_constraints *constraints)
37 {
38 	u32 pval;
39 	int i;
40 	static const char *const props[] = {
41 		"regulator-oc-%s-microamp",
42 		"regulator-ov-%s-microvolt",
43 		"regulator-temp-%s-kelvin",
44 		"regulator-uv-%s-microvolt",
45 	};
46 	struct notification_limit *limits[] = {
47 		&constraints->over_curr_limits,
48 		&constraints->over_voltage_limits,
49 		&constraints->temp_limits,
50 		&constraints->under_voltage_limits,
51 	};
52 	bool set[4] = {0};
53 
54 	/* Protection limits: */
55 	for (i = 0; i < ARRAY_SIZE(props); i++) {
56 		char prop[255];
57 		bool found;
58 		int j;
59 		static const char *const lvl[] = {
60 			"protection", "error", "warn"
61 		};
62 		int *l[] = {
63 			&limits[i]->prot, &limits[i]->err, &limits[i]->warn,
64 		};
65 
66 		for (j = 0; j < ARRAY_SIZE(lvl); j++) {
67 			snprintf(prop, 255, props[i], lvl[j]);
68 			found = !of_property_read_u32(np, prop, &pval);
69 			if (found)
70 				fill_limit(l[j], pval);
71 			set[i] |= found;
72 		}
73 	}
74 	constraints->over_current_detection = set[0];
75 	constraints->over_voltage_detection = set[1];
76 	constraints->over_temp_detection = set[2];
77 	constraints->under_voltage_detection = set[3];
78 }
79 
80 static int of_get_regulation_constraints(struct device *dev,
81 					struct device_node *np,
82 					struct regulator_init_data **init_data,
83 					const struct regulator_desc *desc)
84 {
85 	struct regulation_constraints *constraints = &(*init_data)->constraints;
86 	struct regulator_state *suspend_state;
87 	struct device_node *suspend_np;
88 	unsigned int mode;
89 	int ret, i, len;
90 	int n_phandles;
91 	u32 pval;
92 
93 	n_phandles = of_count_phandle_with_args(np, "regulator-coupled-with",
94 						NULL);
95 	n_phandles = max(n_phandles, 0);
96 
97 	constraints->name = of_get_property(np, "regulator-name", NULL);
98 
99 	if (!of_property_read_u32(np, "regulator-min-microvolt", &pval))
100 		constraints->min_uV = pval;
101 
102 	if (!of_property_read_u32(np, "regulator-max-microvolt", &pval))
103 		constraints->max_uV = pval;
104 
105 	/* Voltage change possible? */
106 	if (constraints->min_uV != constraints->max_uV)
107 		constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
108 
109 	/* Do we have a voltage range, if so try to apply it? */
110 	if (constraints->min_uV && constraints->max_uV)
111 		constraints->apply_uV = true;
112 
113 	if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
114 		constraints->uV_offset = pval;
115 	if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
116 		constraints->min_uA = pval;
117 	if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
118 		constraints->max_uA = pval;
119 
120 	if (!of_property_read_u32(np, "regulator-input-current-limit-microamp",
121 				  &pval))
122 		constraints->ilim_uA = pval;
123 
124 	/* Current change possible? */
125 	if (constraints->min_uA != constraints->max_uA)
126 		constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
127 
128 	constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
129 	constraints->always_on = of_property_read_bool(np, "regulator-always-on");
130 	if (!constraints->always_on) /* status change should be possible. */
131 		constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
132 
133 	constraints->pull_down = of_property_read_bool(np, "regulator-pull-down");
134 
135 	if (of_property_read_bool(np, "regulator-allow-bypass"))
136 		constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
137 
138 	if (of_property_read_bool(np, "regulator-allow-set-load"))
139 		constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;
140 
141 	ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
142 	if (!ret) {
143 		if (pval)
144 			constraints->ramp_delay = pval;
145 		else
146 			constraints->ramp_disable = true;
147 	}
148 
149 	ret = of_property_read_u32(np, "regulator-settling-time-us", &pval);
150 	if (!ret)
151 		constraints->settling_time = pval;
152 
153 	ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
154 	if (!ret)
155 		constraints->settling_time_up = pval;
156 	if (constraints->settling_time_up && constraints->settling_time) {
157 		pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
158 			np);
159 		constraints->settling_time_up = 0;
160 	}
161 
162 	ret = of_property_read_u32(np, "regulator-settling-time-down-us",
163 				   &pval);
164 	if (!ret)
165 		constraints->settling_time_down = pval;
166 	if (constraints->settling_time_down && constraints->settling_time) {
167 		pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
168 			np);
169 		constraints->settling_time_down = 0;
170 	}
171 
172 	ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
173 	if (!ret)
174 		constraints->enable_time = pval;
175 
176 	constraints->soft_start = of_property_read_bool(np,
177 					"regulator-soft-start");
178 	ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
179 	if (!ret) {
180 		constraints->active_discharge =
181 				(pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
182 					REGULATOR_ACTIVE_DISCHARGE_DISABLE;
183 	}
184 
185 	if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
186 		if (desc && desc->of_map_mode) {
187 			mode = desc->of_map_mode(pval);
188 			if (mode == REGULATOR_MODE_INVALID)
189 				pr_err("%pOFn: invalid mode %u\n", np, pval);
190 			else
191 				constraints->initial_mode = mode;
192 		} else {
193 			pr_warn("%pOFn: mapping for mode %d not defined\n",
194 				np, pval);
195 		}
196 	}
197 
198 	len = of_property_count_elems_of_size(np, "regulator-allowed-modes",
199 						sizeof(u32));
200 	if (len > 0) {
201 		if (desc && desc->of_map_mode) {
202 			for (i = 0; i < len; i++) {
203 				ret = of_property_read_u32_index(np,
204 					"regulator-allowed-modes", i, &pval);
205 				if (ret) {
206 					pr_err("%pOFn: couldn't read allowed modes index %d, ret=%d\n",
207 						np, i, ret);
208 					break;
209 				}
210 				mode = desc->of_map_mode(pval);
211 				if (mode == REGULATOR_MODE_INVALID)
212 					pr_err("%pOFn: invalid regulator-allowed-modes element %u\n",
213 						np, pval);
214 				else
215 					constraints->valid_modes_mask |= mode;
216 			}
217 			if (constraints->valid_modes_mask)
218 				constraints->valid_ops_mask
219 					|= REGULATOR_CHANGE_MODE;
220 		} else {
221 			pr_warn("%pOFn: mode mapping not defined\n", np);
222 		}
223 	}
224 
225 	if (!of_property_read_u32(np, "regulator-system-load", &pval))
226 		constraints->system_load = pval;
227 
228 	if (n_phandles) {
229 		constraints->max_spread = devm_kzalloc(dev,
230 				sizeof(*constraints->max_spread) * n_phandles,
231 				GFP_KERNEL);
232 
233 		if (!constraints->max_spread)
234 			return -ENOMEM;
235 
236 		of_property_read_u32_array(np, "regulator-coupled-max-spread",
237 					   constraints->max_spread, n_phandles);
238 	}
239 
240 	if (!of_property_read_u32(np, "regulator-max-step-microvolt",
241 				  &pval))
242 		constraints->max_uV_step = pval;
243 
244 	constraints->over_current_protection = of_property_read_bool(np,
245 					"regulator-over-current-protection");
246 
247 	of_get_regulator_prot_limits(np, constraints);
248 
249 	for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
250 		switch (i) {
251 		case PM_SUSPEND_MEM:
252 			suspend_state = &constraints->state_mem;
253 			break;
254 		case PM_SUSPEND_MAX:
255 			suspend_state = &constraints->state_disk;
256 			break;
257 		case PM_SUSPEND_STANDBY:
258 			suspend_state = &constraints->state_standby;
259 			break;
260 		case PM_SUSPEND_ON:
261 		case PM_SUSPEND_TO_IDLE:
262 		default:
263 			continue;
264 		}
265 
266 		suspend_np = of_get_child_by_name(np, regulator_states[i]);
267 		if (!suspend_np || !suspend_state)
268 			continue;
269 
270 		if (!of_property_read_u32(suspend_np, "regulator-mode",
271 					  &pval)) {
272 			if (desc && desc->of_map_mode) {
273 				mode = desc->of_map_mode(pval);
274 				if (mode == REGULATOR_MODE_INVALID)
275 					pr_err("%pOFn: invalid mode %u\n",
276 					       np, pval);
277 				else
278 					suspend_state->mode = mode;
279 			} else {
280 				pr_warn("%pOFn: mapping for mode %d not defined\n",
281 					np, pval);
282 			}
283 		}
284 
285 		if (of_property_read_bool(suspend_np,
286 					"regulator-on-in-suspend"))
287 			suspend_state->enabled = ENABLE_IN_SUSPEND;
288 		else if (of_property_read_bool(suspend_np,
289 					"regulator-off-in-suspend"))
290 			suspend_state->enabled = DISABLE_IN_SUSPEND;
291 
292 		if (!of_property_read_u32(suspend_np,
293 				"regulator-suspend-min-microvolt", &pval))
294 			suspend_state->min_uV = pval;
295 
296 		if (!of_property_read_u32(suspend_np,
297 				"regulator-suspend-max-microvolt", &pval))
298 			suspend_state->max_uV = pval;
299 
300 		if (!of_property_read_u32(suspend_np,
301 					"regulator-suspend-microvolt", &pval))
302 			suspend_state->uV = pval;
303 		else /* otherwise use min_uV as default suspend voltage */
304 			suspend_state->uV = suspend_state->min_uV;
305 
306 		if (of_property_read_bool(suspend_np,
307 					"regulator-changeable-in-suspend"))
308 			suspend_state->changeable = true;
309 
310 		if (i == PM_SUSPEND_MEM)
311 			constraints->initial_state = PM_SUSPEND_MEM;
312 
313 		of_node_put(suspend_np);
314 		suspend_state = NULL;
315 		suspend_np = NULL;
316 	}
317 
318 	return 0;
319 }
320 
321 /**
322  * of_get_regulator_init_data - extract regulator_init_data structure info
323  * @dev: device requesting for regulator_init_data
324  * @node: regulator device node
325  * @desc: regulator description
326  *
327  * Populates regulator_init_data structure by extracting data from device
328  * tree node, returns a pointer to the populated structure or NULL if memory
329  * alloc fails.
330  */
331 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
332 					  struct device_node *node,
333 					  const struct regulator_desc *desc)
334 {
335 	struct regulator_init_data *init_data;
336 
337 	if (!node)
338 		return NULL;
339 
340 	init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
341 	if (!init_data)
342 		return NULL; /* Out of memory? */
343 
344 	if (of_get_regulation_constraints(dev, node, &init_data, desc))
345 		return NULL;
346 
347 	return init_data;
348 }
349 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
350 
351 struct devm_of_regulator_matches {
352 	struct of_regulator_match *matches;
353 	unsigned int num_matches;
354 };
355 
356 static void devm_of_regulator_put_matches(struct device *dev, void *res)
357 {
358 	struct devm_of_regulator_matches *devm_matches = res;
359 	int i;
360 
361 	for (i = 0; i < devm_matches->num_matches; i++)
362 		of_node_put(devm_matches->matches[i].of_node);
363 }
364 
365 /**
366  * of_regulator_match - extract multiple regulator init data from device tree.
367  * @dev: device requesting the data
368  * @node: parent device node of the regulators
369  * @matches: match table for the regulators
370  * @num_matches: number of entries in match table
371  *
372  * This function uses a match table specified by the regulator driver to
373  * parse regulator init data from the device tree. @node is expected to
374  * contain a set of child nodes, each providing the init data for one
375  * regulator. The data parsed from a child node will be matched to a regulator
376  * based on either the deprecated property regulator-compatible if present,
377  * or otherwise the child node's name. Note that the match table is modified
378  * in place and an additional of_node reference is taken for each matched
379  * regulator.
380  *
381  * Returns the number of matches found or a negative error code on failure.
382  */
383 int of_regulator_match(struct device *dev, struct device_node *node,
384 		       struct of_regulator_match *matches,
385 		       unsigned int num_matches)
386 {
387 	unsigned int count = 0;
388 	unsigned int i;
389 	const char *name;
390 	struct device_node *child;
391 	struct devm_of_regulator_matches *devm_matches;
392 
393 	if (!dev || !node)
394 		return -EINVAL;
395 
396 	devm_matches = devres_alloc(devm_of_regulator_put_matches,
397 				    sizeof(struct devm_of_regulator_matches),
398 				    GFP_KERNEL);
399 	if (!devm_matches)
400 		return -ENOMEM;
401 
402 	devm_matches->matches = matches;
403 	devm_matches->num_matches = num_matches;
404 
405 	devres_add(dev, devm_matches);
406 
407 	for (i = 0; i < num_matches; i++) {
408 		struct of_regulator_match *match = &matches[i];
409 		match->init_data = NULL;
410 		match->of_node = NULL;
411 	}
412 
413 	for_each_child_of_node(node, child) {
414 		name = of_get_property(child,
415 					"regulator-compatible", NULL);
416 		if (!name)
417 			name = child->name;
418 		for (i = 0; i < num_matches; i++) {
419 			struct of_regulator_match *match = &matches[i];
420 			if (match->of_node)
421 				continue;
422 
423 			if (strcmp(match->name, name))
424 				continue;
425 
426 			match->init_data =
427 				of_get_regulator_init_data(dev, child,
428 							   match->desc);
429 			if (!match->init_data) {
430 				dev_err(dev,
431 					"failed to parse DT for regulator %pOFn\n",
432 					child);
433 				of_node_put(child);
434 				return -EINVAL;
435 			}
436 			match->of_node = of_node_get(child);
437 			count++;
438 			break;
439 		}
440 	}
441 
442 	return count;
443 }
444 EXPORT_SYMBOL_GPL(of_regulator_match);
445 
446 static struct
447 device_node *regulator_of_get_init_node(struct device *dev,
448 					const struct regulator_desc *desc)
449 {
450 	struct device_node *search, *child;
451 	const char *name;
452 
453 	if (!dev->of_node || !desc->of_match)
454 		return NULL;
455 
456 	if (desc->regulators_node) {
457 		search = of_get_child_by_name(dev->of_node,
458 					      desc->regulators_node);
459 	} else {
460 		search = of_node_get(dev->of_node);
461 
462 		if (!strcmp(desc->of_match, search->name))
463 			return search;
464 	}
465 
466 	if (!search) {
467 		dev_dbg(dev, "Failed to find regulator container node '%s'\n",
468 			desc->regulators_node);
469 		return NULL;
470 	}
471 
472 	for_each_available_child_of_node(search, child) {
473 		name = of_get_property(child, "regulator-compatible", NULL);
474 		if (!name) {
475 			if (!desc->of_match_full_name)
476 				name = child->name;
477 			else
478 				name = child->full_name;
479 		}
480 
481 		if (!strcmp(desc->of_match, name)) {
482 			of_node_put(search);
483 			/*
484 			 * 'of_node_get(child)' is already performed by the
485 			 * for_each loop.
486 			 */
487 			return child;
488 		}
489 	}
490 
491 	of_node_put(search);
492 
493 	return NULL;
494 }
495 
496 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
497 					    const struct regulator_desc *desc,
498 					    struct regulator_config *config,
499 					    struct device_node **node)
500 {
501 	struct device_node *child;
502 	struct regulator_init_data *init_data = NULL;
503 
504 	child = regulator_of_get_init_node(dev, desc);
505 	if (!child)
506 		return NULL;
507 
508 	init_data = of_get_regulator_init_data(dev, child, desc);
509 	if (!init_data) {
510 		dev_err(dev, "failed to parse DT for regulator %pOFn\n", child);
511 		goto error;
512 	}
513 
514 	if (desc->of_parse_cb) {
515 		int ret;
516 
517 		ret = desc->of_parse_cb(child, desc, config);
518 		if (ret) {
519 			if (ret == -EPROBE_DEFER) {
520 				of_node_put(child);
521 				return ERR_PTR(-EPROBE_DEFER);
522 			}
523 			dev_err(dev,
524 				"driver callback failed to parse DT for regulator %pOFn\n",
525 				child);
526 			goto error;
527 		}
528 	}
529 
530 	*node = child;
531 
532 	return init_data;
533 
534 error:
535 	of_node_put(child);
536 
537 	return NULL;
538 }
539 
540 struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
541 {
542 	struct device *dev;
543 
544 	dev = class_find_device_by_of_node(&regulator_class, np);
545 
546 	return dev ? dev_to_rdev(dev) : NULL;
547 }
548 
549 /*
550  * Returns number of regulators coupled with rdev.
551  */
552 int of_get_n_coupled(struct regulator_dev *rdev)
553 {
554 	struct device_node *node = rdev->dev.of_node;
555 	int n_phandles;
556 
557 	n_phandles = of_count_phandle_with_args(node,
558 						"regulator-coupled-with",
559 						NULL);
560 
561 	return (n_phandles > 0) ? n_phandles : 0;
562 }
563 
564 /* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
565 static bool of_coupling_find_node(struct device_node *src,
566 				  struct device_node *to_find,
567 				  int *index)
568 {
569 	int n_phandles, i;
570 	bool found = false;
571 
572 	n_phandles = of_count_phandle_with_args(src,
573 						"regulator-coupled-with",
574 						NULL);
575 
576 	for (i = 0; i < n_phandles; i++) {
577 		struct device_node *tmp = of_parse_phandle(src,
578 					   "regulator-coupled-with", i);
579 
580 		if (!tmp)
581 			break;
582 
583 		/* found */
584 		if (tmp == to_find)
585 			found = true;
586 
587 		of_node_put(tmp);
588 
589 		if (found) {
590 			*index = i;
591 			break;
592 		}
593 	}
594 
595 	return found;
596 }
597 
598 /**
599  * of_check_coupling_data - Parse rdev's coupling properties and check data
600  *			    consistency
601  * @rdev: pointer to regulator_dev whose data is checked
602  *
603  * Function checks if all the following conditions are met:
604  * - rdev's max_spread is greater than 0
605  * - all coupled regulators have the same max_spread
606  * - all coupled regulators have the same number of regulator_dev phandles
607  * - all regulators are linked to each other
608  *
609  * Returns true if all conditions are met.
610  */
611 bool of_check_coupling_data(struct regulator_dev *rdev)
612 {
613 	struct device_node *node = rdev->dev.of_node;
614 	int n_phandles = of_get_n_coupled(rdev);
615 	struct device_node *c_node;
616 	int index;
617 	int i;
618 	bool ret = true;
619 
620 	/* iterate over rdev's phandles */
621 	for (i = 0; i < n_phandles; i++) {
622 		int max_spread = rdev->constraints->max_spread[i];
623 		int c_max_spread, c_n_phandles;
624 
625 		if (max_spread <= 0) {
626 			dev_err(&rdev->dev, "max_spread value invalid\n");
627 			return false;
628 		}
629 
630 		c_node = of_parse_phandle(node,
631 					  "regulator-coupled-with", i);
632 
633 		if (!c_node)
634 			ret = false;
635 
636 		c_n_phandles = of_count_phandle_with_args(c_node,
637 							  "regulator-coupled-with",
638 							  NULL);
639 
640 		if (c_n_phandles != n_phandles) {
641 			dev_err(&rdev->dev, "number of coupled reg phandles mismatch\n");
642 			ret = false;
643 			goto clean;
644 		}
645 
646 		if (!of_coupling_find_node(c_node, node, &index)) {
647 			dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
648 			ret = false;
649 			goto clean;
650 		}
651 
652 		if (of_property_read_u32_index(c_node, "regulator-coupled-max-spread",
653 					       index, &c_max_spread)) {
654 			ret = false;
655 			goto clean;
656 		}
657 
658 		if (c_max_spread != max_spread) {
659 			dev_err(&rdev->dev,
660 				"coupled regulators max_spread mismatch\n");
661 			ret = false;
662 			goto clean;
663 		}
664 
665 clean:
666 		of_node_put(c_node);
667 		if (!ret)
668 			break;
669 	}
670 
671 	return ret;
672 }
673 
674 /**
675  * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
676  * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
677  *	  "regulator-coupled-with" property
678  * @index: Index in phandles array
679  *
680  * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
681  * registered, returns NULL
682  */
683 struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
684 						 int index)
685 {
686 	struct device_node *node = rdev->dev.of_node;
687 	struct device_node *c_node;
688 	struct regulator_dev *c_rdev;
689 
690 	c_node = of_parse_phandle(node, "regulator-coupled-with", index);
691 	if (!c_node)
692 		return NULL;
693 
694 	c_rdev = of_find_regulator_by_node(c_node);
695 
696 	of_node_put(c_node);
697 
698 	return c_rdev;
699 }
700