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
18static 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
24static 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)
210			continue;
211		if (!suspend_state) {
212			of_node_put(suspend_np);
213			continue;
214		}
215
216		if (!of_property_read_u32(suspend_np, "regulator-mode",
217					  &pval)) {
218			if (desc && desc->of_map_mode) {
219				mode = desc->of_map_mode(pval);
220				if (mode == REGULATOR_MODE_INVALID)
221					pr_err("%pOFn: invalid mode %u\n",
222					       np, pval);
223				else
224					suspend_state->mode = mode;
225			} else {
226				pr_warn("%pOFn: mapping for mode %d not defined\n",
227					np, pval);
228			}
229		}
230
231		if (of_property_read_bool(suspend_np,
232					"regulator-on-in-suspend"))
233			suspend_state->enabled = ENABLE_IN_SUSPEND;
234		else if (of_property_read_bool(suspend_np,
235					"regulator-off-in-suspend"))
236			suspend_state->enabled = DISABLE_IN_SUSPEND;
237
238		if (!of_property_read_u32(suspend_np,
239				"regulator-suspend-min-microvolt", &pval))
240			suspend_state->min_uV = pval;
241
242		if (!of_property_read_u32(suspend_np,
243				"regulator-suspend-max-microvolt", &pval))
244			suspend_state->max_uV = pval;
245
246		if (!of_property_read_u32(suspend_np,
247					"regulator-suspend-microvolt", &pval))
248			suspend_state->uV = pval;
249		else /* otherwise use min_uV as default suspend voltage */
250			suspend_state->uV = suspend_state->min_uV;
251
252		if (of_property_read_bool(suspend_np,
253					"regulator-changeable-in-suspend"))
254			suspend_state->changeable = true;
255
256		if (i == PM_SUSPEND_MEM)
257			constraints->initial_state = PM_SUSPEND_MEM;
258
259		of_node_put(suspend_np);
260		suspend_state = NULL;
261		suspend_np = NULL;
262	}
263
264	return 0;
265}
266
267/**
268 * of_get_regulator_init_data - extract regulator_init_data structure info
269 * @dev: device requesting for regulator_init_data
270 * @node: regulator device node
271 * @desc: regulator description
272 *
273 * Populates regulator_init_data structure by extracting data from device
274 * tree node, returns a pointer to the populated structure or NULL if memory
275 * alloc fails.
276 */
277struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
278					  struct device_node *node,
279					  const struct regulator_desc *desc)
280{
281	struct regulator_init_data *init_data;
282
283	if (!node)
284		return NULL;
285
286	init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
287	if (!init_data)
288		return NULL; /* Out of memory? */
289
290	if (of_get_regulation_constraints(dev, node, &init_data, desc))
291		return NULL;
292
293	return init_data;
294}
295EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
296
297struct devm_of_regulator_matches {
298	struct of_regulator_match *matches;
299	unsigned int num_matches;
300};
301
302static void devm_of_regulator_put_matches(struct device *dev, void *res)
303{
304	struct devm_of_regulator_matches *devm_matches = res;
305	int i;
306
307	for (i = 0; i < devm_matches->num_matches; i++)
308		of_node_put(devm_matches->matches[i].of_node);
309}
310
311/**
312 * of_regulator_match - extract multiple regulator init data from device tree.
313 * @dev: device requesting the data
314 * @node: parent device node of the regulators
315 * @matches: match table for the regulators
316 * @num_matches: number of entries in match table
317 *
318 * This function uses a match table specified by the regulator driver to
319 * parse regulator init data from the device tree. @node is expected to
320 * contain a set of child nodes, each providing the init data for one
321 * regulator. The data parsed from a child node will be matched to a regulator
322 * based on either the deprecated property regulator-compatible if present,
323 * or otherwise the child node's name. Note that the match table is modified
324 * in place and an additional of_node reference is taken for each matched
325 * regulator.
326 *
327 * Returns the number of matches found or a negative error code on failure.
328 */
329int of_regulator_match(struct device *dev, struct device_node *node,
330		       struct of_regulator_match *matches,
331		       unsigned int num_matches)
332{
333	unsigned int count = 0;
334	unsigned int i;
335	const char *name;
336	struct device_node *child;
337	struct devm_of_regulator_matches *devm_matches;
338
339	if (!dev || !node)
340		return -EINVAL;
341
342	devm_matches = devres_alloc(devm_of_regulator_put_matches,
343				    sizeof(struct devm_of_regulator_matches),
344				    GFP_KERNEL);
345	if (!devm_matches)
346		return -ENOMEM;
347
348	devm_matches->matches = matches;
349	devm_matches->num_matches = num_matches;
350
351	devres_add(dev, devm_matches);
352
353	for (i = 0; i < num_matches; i++) {
354		struct of_regulator_match *match = &matches[i];
355		match->init_data = NULL;
356		match->of_node = NULL;
357	}
358
359	for_each_child_of_node(node, child) {
360		name = of_get_property(child,
361					"regulator-compatible", NULL);
362		if (!name)
363			name = child->name;
364		for (i = 0; i < num_matches; i++) {
365			struct of_regulator_match *match = &matches[i];
366			if (match->of_node)
367				continue;
368
369			if (strcmp(match->name, name))
370				continue;
371
372			match->init_data =
373				of_get_regulator_init_data(dev, child,
374							   match->desc);
375			if (!match->init_data) {
376				dev_err(dev,
377					"failed to parse DT for regulator %pOFn\n",
378					child);
379				of_node_put(child);
380				return -EINVAL;
381			}
382			match->of_node = of_node_get(child);
383			count++;
384			break;
385		}
386	}
387
388	return count;
389}
390EXPORT_SYMBOL_GPL(of_regulator_match);
391
392static struct
393device_node *regulator_of_get_init_node(struct device *dev,
394					const struct regulator_desc *desc)
395{
396	struct device_node *search, *child;
397	const char *name;
398
399	if (!dev->of_node || !desc->of_match)
400		return NULL;
401
402	if (desc->regulators_node) {
403		search = of_get_child_by_name(dev->of_node,
404					      desc->regulators_node);
405	} else {
406		search = of_node_get(dev->of_node);
407
408		if (!strcmp(desc->of_match, search->name))
409			return search;
410	}
411
412	if (!search) {
413		dev_dbg(dev, "Failed to find regulator container node '%s'\n",
414			desc->regulators_node);
415		return NULL;
416	}
417
418	for_each_available_child_of_node(search, child) {
419		name = of_get_property(child, "regulator-compatible", NULL);
420		if (!name)
421			name = child->name;
422
423		if (!strcmp(desc->of_match, name)) {
424			of_node_put(search);
425			return of_node_get(child);
426		}
427	}
428
429	of_node_put(search);
430
431	return NULL;
432}
433
434struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
435					    const struct regulator_desc *desc,
436					    struct regulator_config *config,
437					    struct device_node **node)
438{
439	struct device_node *child;
440	struct regulator_init_data *init_data = NULL;
441
442	child = regulator_of_get_init_node(dev, desc);
443	if (!child)
444		return NULL;
445
446	init_data = of_get_regulator_init_data(dev, child, desc);
447	if (!init_data) {
448		dev_err(dev, "failed to parse DT for regulator %pOFn\n", child);
449		goto error;
450	}
451
452	if (desc->of_parse_cb) {
453		int ret;
454
455		ret = desc->of_parse_cb(child, desc, config);
456		if (ret) {
457			if (ret == -EPROBE_DEFER) {
458				of_node_put(child);
459				return ERR_PTR(-EPROBE_DEFER);
460			}
461			dev_err(dev,
462				"driver callback failed to parse DT for regulator %pOFn\n",
463				child);
464			goto error;
465		}
466	}
467
468	*node = child;
469
470	return init_data;
471
472error:
473	of_node_put(child);
474
475	return NULL;
476}
477
478struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
479{
480	struct device *dev;
481
482	dev = class_find_device_by_of_node(&regulator_class, np);
483
484	return dev ? dev_to_rdev(dev) : NULL;
485}
486
487/*
488 * Returns number of regulators coupled with rdev.
489 */
490int of_get_n_coupled(struct regulator_dev *rdev)
491{
492	struct device_node *node = rdev->dev.of_node;
493	int n_phandles;
494
495	n_phandles = of_count_phandle_with_args(node,
496						"regulator-coupled-with",
497						NULL);
498
499	return (n_phandles > 0) ? n_phandles : 0;
500}
501
502/* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
503static bool of_coupling_find_node(struct device_node *src,
504				  struct device_node *to_find,
505				  int *index)
506{
507	int n_phandles, i;
508	bool found = false;
509
510	n_phandles = of_count_phandle_with_args(src,
511						"regulator-coupled-with",
512						NULL);
513
514	for (i = 0; i < n_phandles; i++) {
515		struct device_node *tmp = of_parse_phandle(src,
516					   "regulator-coupled-with", i);
517
518		if (!tmp)
519			break;
520
521		/* found */
522		if (tmp == to_find)
523			found = true;
524
525		of_node_put(tmp);
526
527		if (found) {
528			*index = i;
529			break;
530		}
531	}
532
533	return found;
534}
535
536/**
537 * of_check_coupling_data - Parse rdev's coupling properties and check data
538 *			    consistency
539 * @rdev: pointer to regulator_dev whose data is checked
540 *
541 * Function checks if all the following conditions are met:
542 * - rdev's max_spread is greater than 0
543 * - all coupled regulators have the same max_spread
544 * - all coupled regulators have the same number of regulator_dev phandles
545 * - all regulators are linked to each other
546 *
547 * Returns true if all conditions are met.
548 */
549bool of_check_coupling_data(struct regulator_dev *rdev)
550{
551	struct device_node *node = rdev->dev.of_node;
552	int n_phandles = of_get_n_coupled(rdev);
553	struct device_node *c_node;
554	int index;
555	int i;
556	bool ret = true;
557
558	/* iterate over rdev's phandles */
559	for (i = 0; i < n_phandles; i++) {
560		int max_spread = rdev->constraints->max_spread[i];
561		int c_max_spread, c_n_phandles;
562
563		if (max_spread <= 0) {
564			dev_err(&rdev->dev, "max_spread value invalid\n");
565			return false;
566		}
567
568		c_node = of_parse_phandle(node,
569					  "regulator-coupled-with", i);
570
571		if (!c_node)
572			ret = false;
573
574		c_n_phandles = of_count_phandle_with_args(c_node,
575							  "regulator-coupled-with",
576							  NULL);
577
578		if (c_n_phandles != n_phandles) {
579			dev_err(&rdev->dev, "number of coupled reg phandles mismatch\n");
580			ret = false;
581			goto clean;
582		}
583
584		if (!of_coupling_find_node(c_node, node, &index)) {
585			dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
586			ret = false;
587			goto clean;
588		}
589
590		if (of_property_read_u32_index(c_node, "regulator-coupled-max-spread",
591					       index, &c_max_spread)) {
592			ret = false;
593			goto clean;
594		}
595
596		if (c_max_spread != max_spread) {
597			dev_err(&rdev->dev,
598				"coupled regulators max_spread mismatch\n");
599			ret = false;
600			goto clean;
601		}
602
603clean:
604		of_node_put(c_node);
605		if (!ret)
606			break;
607	}
608
609	return ret;
610}
611
612/**
613 * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
614 * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
615 *	  "regulator-coupled-with" property
616 * @index: Index in phandles array
617 *
618 * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
619 * registered, returns NULL
620 */
621struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
622						 int index)
623{
624	struct device_node *node = rdev->dev.of_node;
625	struct device_node *c_node;
626	struct regulator_dev *c_rdev;
627
628	c_node = of_parse_phandle(node, "regulator-coupled-with", index);
629	if (!c_node)
630		return NULL;
631
632	c_rdev = of_find_regulator_by_node(c_node);
633
634	of_node_put(c_node);
635
636	return c_rdev;
637}
638