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