drivers/regulator/of_regulator.c

   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         const __be32 *min_uV, *max_uV;
  32         struct regulation_constraints *constraints = &(*init_data)->constraints;
  33         struct regulator_state *suspend_state;
  34         struct device_node *suspend_np;
  35         int ret, i;
  36         u32 pval;
  37
  38         constraints->name = of_get_property(np, "regulator-name", NULL);
  39
  40         min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
  41         if (min_uV)
  42                 constraints->min_uV = be32_to_cpu(*min_uV);
  43         max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
  44         if (max_uV)
  45                 constraints->max_uV = be32_to_cpu(*max_uV);
  46
  47         /* Voltage change possible? */
  48         if (constraints->min_uV != constraints->max_uV)
  49                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  50         /* Only one voltage?  Then make sure it's set. */
  51         if (min_uV && max_uV && 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         /* Current change possible? */
  62         if (constraints->min_uA != constraints->max_uA)
  63                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  64
  65         constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
  66         constraints->always_on = of_property_read_bool(np, "regulator-always-on");
  67         if (!constraints->always_on) /* status change should be possible. */
  68                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  69
  70         if (of_property_read_bool(np, "regulator-allow-bypass"))
  71                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  72
  73         ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
  74         if (!ret) {
  75                 if (pval)
  76                         constraints->ramp_delay = pval;
  77                 else
  78                         constraints->ramp_disable = true;
  79         }
  80
  81         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
  82         if (!ret)
  83                 constraints->enable_time = pval;
  84
  85         if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
  86                 if (desc && desc->of_map_mode) {
  87                         ret = desc->of_map_mode(pval);
  88                         if (ret == -EINVAL)
  89                                 pr_err("%s: invalid mode %u\n", np->name, pval);
  90                         else
  91                                 constraints->initial_mode = ret;
  92                 } else {
  93                         pr_warn("%s: mapping for mode %d not defined\n",
  94                                 np->name, pval);
  95                 }
  96         }
  97
  98         if (!of_property_read_u32(np, "regulator-system-load", &pval))
  99                 constraints->system_load = pval;
 100
 101         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 102                 switch (i) {
 103                 case PM_SUSPEND_MEM:
 104                         suspend_state = &constraints->state_mem;
 105                         break;
 106                 case PM_SUSPEND_MAX:
 107                         suspend_state = &constraints->state_disk;
 108                         break;
 109                 case PM_SUSPEND_ON:
 110                 case PM_SUSPEND_FREEZE:
 111                 case PM_SUSPEND_STANDBY:
 112                 default:
 113                         continue;
 114                 };
 115
 116                 suspend_np = of_get_child_by_name(np, regulator_states[i]);
 117                 if (!suspend_np || !suspend_state)
 118                         continue;
 119
 120                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 121                                           &pval)) {
 122                         if (desc && desc->of_map_mode) {
 123                                 ret = desc->of_map_mode(pval);
 124                                 if (ret == -EINVAL)
 125                                         pr_err("%s: invalid mode %u\n",
 126                                                np->name, pval);
 127                                 else
 128                                         suspend_state->mode = ret;
 129                         } else {
 130                                 pr_warn("%s: mapping for mode %d not defined\n",
 131                                         np->name, pval);
 132                         }
 133                 }
 134
 135                 if (of_property_read_bool(suspend_np,
 136                                         "regulator-on-in-suspend"))
 137                         suspend_state->enabled = true;
 138                 else if (of_property_read_bool(suspend_np,
 139                                         "regulator-off-in-suspend"))
 140                         suspend_state->disabled = true;
 141
 142                 if (!of_property_read_u32(suspend_np,
 143                                         "regulator-suspend-microvolt", &pval))
 144                         suspend_state->uV = pval;
 145
 146                 of_node_put(suspend_np);
 147                 suspend_state = NULL;
 148                 suspend_np = NULL;
 149         }
 150 }
 151
 152 /**
 153  * of_get_regulator_init_data - extract regulator_init_data structure info
 154  * @dev: device requesting for regulator_init_data
 155  * @node: regulator device node
 156  * @desc: regulator description
 157  *
 158  * Populates regulator_init_data structure by extracting data from device
 159  * tree node, returns a pointer to the populated struture or NULL if memory
 160  * alloc fails.
 161  */
 162 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 163                                           struct device_node *node,
 164                                           const struct regulator_desc *desc)
 165 {
 166         struct regulator_init_data *init_data;
 167
 168         if (!node)
 169                 return NULL;
 170
 171         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 172         if (!init_data)
 173                 return NULL; /* Out of memory? */
 174
 175         of_get_regulation_constraints(node, &init_data, desc);
 176         return init_data;
 177 }
 178 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 179
 180 struct devm_of_regulator_matches {
 181         struct of_regulator_match *matches;
 182         unsigned int num_matches;
 183 };
 184
 185 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 186 {
 187         struct devm_of_regulator_matches *devm_matches = res;
 188         int i;
 189
 190         for (i = 0; i < devm_matches->num_matches; i++)
 191                 of_node_put(devm_matches->matches[i].of_node);
 192 }
 193
 194 /**
 195  * of_regulator_match - extract multiple regulator init data from device tree.
 196  * @dev: device requesting the data
 197  * @node: parent device node of the regulators
 198  * @matches: match table for the regulators
 199  * @num_matches: number of entries in match table
 200  *
 201  * This function uses a match table specified by the regulator driver to
 202  * parse regulator init data from the device tree. @node is expected to
 203  * contain a set of child nodes, each providing the init data for one
 204  * regulator. The data parsed from a child node will be matched to a regulator
 205  * based on either the deprecated property regulator-compatible if present,
 206  * or otherwise the child node's name. Note that the match table is modified
 207  * in place and an additional of_node reference is taken for each matched
 208  * regulator.
 209  *
 210  * Returns the number of matches found or a negative error code on failure.
 211  */
 212 int of_regulator_match(struct device *dev, struct device_node *node,
 213                        struct of_regulator_match *matches,
 214                        unsigned int num_matches)
 215 {
 216         unsigned int count = 0;
 217         unsigned int i;
 218         const char *name;
 219         struct device_node *child;
 220         struct devm_of_regulator_matches *devm_matches;
 221
 222         if (!dev || !node)
 223                 return -EINVAL;
 224
 225         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 226                                     sizeof(struct devm_of_regulator_matches),
 227                                     GFP_KERNEL);
 228         if (!devm_matches)
 229                 return -ENOMEM;
 230
 231         devm_matches->matches = matches;
 232         devm_matches->num_matches = num_matches;
 233
 234         devres_add(dev, devm_matches);
 235
 236         for (i = 0; i < num_matches; i++) {
 237                 struct of_regulator_match *match = &matches[i];
 238                 match->init_data = NULL;
 239                 match->of_node = NULL;
 240         }
 241
 242         for_each_child_of_node(node, child) {
 243                 name = of_get_property(child,
 244                                         "regulator-compatible", NULL);
 245                 if (!name)
 246                         name = child->name;
 247                 for (i = 0; i < num_matches; i++) {
 248                         struct of_regulator_match *match = &matches[i];
 249                         if (match->of_node)
 250                                 continue;
 251
 252                         if (strcmp(match->name, name))
 253                                 continue;
 254
 255                         match->init_data =
 256                                 of_get_regulator_init_data(dev, child,
 257                                                            match->desc);
 258                         if (!match->init_data) {
 259                                 dev_err(dev,
 260                                         "failed to parse DT for regulator %s\n",
 261                                         child->name);
 262                                 return -EINVAL;
 263                         }
 264                         match->of_node = of_node_get(child);
 265                         count++;
 266                         break;
 267                 }
 268         }
 269
 270         return count;
 271 }
 272 EXPORT_SYMBOL_GPL(of_regulator_match);
 273
 274 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 275                                             const struct regulator_desc *desc,
 276                                             struct regulator_config *config,
 277                                             struct device_node **node)
 278 {
 279         struct device_node *search, *child;
 280         struct regulator_init_data *init_data = NULL;
 281         const char *name;
 282
 283         if (!dev->of_node || !desc->of_match)
 284                 return NULL;
 285
 286         if (desc->regulators_node)
 287                 search = of_get_child_by_name(dev->of_node,
 288                                               desc->regulators_node);
 289         else
 290                 search = dev->of_node;
 291
 292         if (!search) {
 293                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 294                         desc->regulators_node);
 295                 return NULL;
 296         }
 297
 298         for_each_child_of_node(search, child) {
 299                 name = of_get_property(child, "regulator-compatible", NULL);
 300                 if (!name)
 301                         name = child->name;
 302
 303                 if (strcmp(desc->of_match, name))
 304                         continue;
 305
 306                 init_data = of_get_regulator_init_data(dev, child, desc);
 307                 if (!init_data) {
 308                         dev_err(dev,
 309                                 "failed to parse DT for regulator %s\n",
 310                                 child->name);
 311                         break;
 312                 }
 313
 314                 if (desc->of_parse_cb) {
 315                         if (desc->of_parse_cb(child, desc, config)) {
 316                                 dev_err(dev,
 317                                         "driver callback failed to parse DT for regulator %s\n",
 318                                         child->name);
 319                                 init_data = NULL;
 320                                 break;
 321                         }
 322                 }
 323
 324                 of_node_get(child);
 325                 *node = child;
 326                 break;
 327         }
 328
 329         of_node_put(search);
 330
 331         return init_data;
 332 }