Merge tag 'regulator-fix-v5.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git...
[sfrench/cifs-2.6.git] / drivers / regulator / of_regulator.c
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 }