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