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