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
of_get_regulation_constraints(struct device * dev,struct device_node * np,struct regulator_init_data ** init_data,const struct regulator_desc * desc)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)
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 */
of_get_regulator_init_data(struct device * dev,struct device_node * node,const struct regulator_desc * desc)277 struct 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 }
295 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
296
297 struct devm_of_regulator_matches {
298 struct of_regulator_match *matches;
299 unsigned int num_matches;
300 };
301
devm_of_regulator_put_matches(struct device * dev,void * res)302 static 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 */
of_regulator_match(struct device * dev,struct device_node * node,struct of_regulator_match * matches,unsigned int num_matches)329 int 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 }
390 EXPORT_SYMBOL_GPL(of_regulator_match);
391
392 static struct
regulator_of_get_init_node(struct device * dev,const struct regulator_desc * desc)393 device_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 if (!desc->of_match_full_name)
422 name = child->name;
423 else
424 name = child->full_name;
425 }
426
427 if (!strcmp(desc->of_match, name)) {
428 of_node_put(search);
429 return of_node_get(child);
430 }
431 }
432
433 of_node_put(search);
434
435 return NULL;
436 }
437
regulator_of_get_init_data(struct device * dev,const struct regulator_desc * desc,struct regulator_config * config,struct device_node ** node)438 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
439 const struct regulator_desc *desc,
440 struct regulator_config *config,
441 struct device_node **node)
442 {
443 struct device_node *child;
444 struct regulator_init_data *init_data = NULL;
445
446 child = regulator_of_get_init_node(dev, desc);
447 if (!child)
448 return NULL;
449
450 init_data = of_get_regulator_init_data(dev, child, desc);
451 if (!init_data) {
452 dev_err(dev, "failed to parse DT for regulator %pOFn\n", child);
453 goto error;
454 }
455
456 if (desc->of_parse_cb) {
457 int ret;
458
459 ret = desc->of_parse_cb(child, desc, config);
460 if (ret) {
461 if (ret == -EPROBE_DEFER) {
462 of_node_put(child);
463 return ERR_PTR(-EPROBE_DEFER);
464 }
465 dev_err(dev,
466 "driver callback failed to parse DT for regulator %pOFn\n",
467 child);
468 goto error;
469 }
470 }
471
472 *node = child;
473
474 return init_data;
475
476 error:
477 of_node_put(child);
478
479 return NULL;
480 }
481
of_find_regulator_by_node(struct device_node * np)482 struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
483 {
484 struct device *dev;
485
486 dev = class_find_device_by_of_node(®ulator_class, np);
487
488 return dev ? dev_to_rdev(dev) : NULL;
489 }
490
491 /*
492 * Returns number of regulators coupled with rdev.
493 */
of_get_n_coupled(struct regulator_dev * rdev)494 int of_get_n_coupled(struct regulator_dev *rdev)
495 {
496 struct device_node *node = rdev->dev.of_node;
497 int n_phandles;
498
499 n_phandles = of_count_phandle_with_args(node,
500 "regulator-coupled-with",
501 NULL);
502
503 return (n_phandles > 0) ? n_phandles : 0;
504 }
505
506 /* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
of_coupling_find_node(struct device_node * src,struct device_node * to_find,int * index)507 static bool of_coupling_find_node(struct device_node *src,
508 struct device_node *to_find,
509 int *index)
510 {
511 int n_phandles, i;
512 bool found = false;
513
514 n_phandles = of_count_phandle_with_args(src,
515 "regulator-coupled-with",
516 NULL);
517
518 for (i = 0; i < n_phandles; i++) {
519 struct device_node *tmp = of_parse_phandle(src,
520 "regulator-coupled-with", i);
521
522 if (!tmp)
523 break;
524
525 /* found */
526 if (tmp == to_find)
527 found = true;
528
529 of_node_put(tmp);
530
531 if (found) {
532 *index = i;
533 break;
534 }
535 }
536
537 return found;
538 }
539
540 /**
541 * of_check_coupling_data - Parse rdev's coupling properties and check data
542 * consistency
543 * @rdev: pointer to regulator_dev whose data is checked
544 *
545 * Function checks if all the following conditions are met:
546 * - rdev's max_spread is greater than 0
547 * - all coupled regulators have the same max_spread
548 * - all coupled regulators have the same number of regulator_dev phandles
549 * - all regulators are linked to each other
550 *
551 * Returns true if all conditions are met.
552 */
of_check_coupling_data(struct regulator_dev * rdev)553 bool of_check_coupling_data(struct regulator_dev *rdev)
554 {
555 struct device_node *node = rdev->dev.of_node;
556 int n_phandles = of_get_n_coupled(rdev);
557 struct device_node *c_node;
558 int index;
559 int i;
560 bool ret = true;
561
562 /* iterate over rdev's phandles */
563 for (i = 0; i < n_phandles; i++) {
564 int max_spread = rdev->constraints->max_spread[i];
565 int c_max_spread, c_n_phandles;
566
567 if (max_spread <= 0) {
568 dev_err(&rdev->dev, "max_spread value invalid\n");
569 return false;
570 }
571
572 c_node = of_parse_phandle(node,
573 "regulator-coupled-with", i);
574
575 if (!c_node)
576 ret = false;
577
578 c_n_phandles = of_count_phandle_with_args(c_node,
579 "regulator-coupled-with",
580 NULL);
581
582 if (c_n_phandles != n_phandles) {
583 dev_err(&rdev->dev, "number of coupled reg phandles mismatch\n");
584 ret = false;
585 goto clean;
586 }
587
588 if (!of_coupling_find_node(c_node, node, &index)) {
589 dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
590 ret = false;
591 goto clean;
592 }
593
594 if (of_property_read_u32_index(c_node, "regulator-coupled-max-spread",
595 index, &c_max_spread)) {
596 ret = false;
597 goto clean;
598 }
599
600 if (c_max_spread != max_spread) {
601 dev_err(&rdev->dev,
602 "coupled regulators max_spread mismatch\n");
603 ret = false;
604 goto clean;
605 }
606
607 clean:
608 of_node_put(c_node);
609 if (!ret)
610 break;
611 }
612
613 return ret;
614 }
615
616 /**
617 * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
618 * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
619 * "regulator-coupled-with" property
620 * @index: Index in phandles array
621 *
622 * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
623 * registered, returns NULL
624 */
of_parse_coupled_regulator(struct regulator_dev * rdev,int index)625 struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
626 int index)
627 {
628 struct device_node *node = rdev->dev.of_node;
629 struct device_node *c_node;
630 struct regulator_dev *c_rdev;
631
632 c_node = of_parse_phandle(node, "regulator-coupled-with", index);
633 if (!c_node)
634 return NULL;
635
636 c_rdev = of_find_regulator_by_node(c_node);
637
638 of_node_put(c_node);
639
640 return c_rdev;
641 }
642