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/of_regulator.h>
  18
  19 static void set_regulator_state_constraints(struct device_node *np,
  20                 struct regulator_state *state)
  21 {
  22         of_property_read_u32(np, "regulator-state-uv", &state->uV);
  23         of_property_read_u32(np, "regulator-state-mode", &state->mode);
  24         state->enabled = of_property_read_bool(np, "regulator-state-enabled");
  25         state->disabled = of_property_read_bool(np, "regulator-state-disabled");
  26 }
  27
  28 static void of_get_regulation_constraints(struct device_node *np,
  29                                         struct regulator_init_data **init_data)
  30 {
  31         const __be32 *min_uV, *max_uV, *uV_offset;
  32         const __be32 *min_uA, *max_uA, *ramp_delay;
  33         struct device_node *state;
  34         struct regulation_constraints *constraints = &(*init_data)->constraints;
  35
  36         constraints->name = of_get_property(np, "regulator-name", NULL);
  37
  38         min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
  39         if (min_uV)
  40                 constraints->min_uV = be32_to_cpu(*min_uV);
  41         max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
  42         if (max_uV)
  43                 constraints->max_uV = be32_to_cpu(*max_uV);
  44
  45         /* Voltage change possible? */
  46         if (constraints->min_uV != constraints->max_uV)
  47                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  48         /* Only one voltage?  Then make sure it's set. */
  49         if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
  50                 constraints->apply_uV = true;
  51
  52         uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);
  53         if (uV_offset)
  54                 constraints->uV_offset = be32_to_cpu(*uV_offset);
  55         min_uA = of_get_property(np, "regulator-min-microamp", NULL);
  56         if (min_uA)
  57                 constraints->min_uA = be32_to_cpu(*min_uA);
  58         max_uA = of_get_property(np, "regulator-max-microamp", NULL);
  59         if (max_uA)
  60                 constraints->max_uA = be32_to_cpu(*max_uA);
  61
  62         /* Current change possible? */
  63         if (constraints->min_uA != constraints->max_uA)
  64                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  65
  66         if (of_find_property(np, "regulator-boot-on", NULL))
  67                 constraints->boot_on = true;
  68
  69         if (of_find_property(np, "regulator-always-on", NULL))
  70                 constraints->always_on = true;
  71         else /* status change should be possible if not always on. */
  72                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  73
  74         ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL);
  75         if (ramp_delay)
  76                 constraints->ramp_delay = be32_to_cpu(*ramp_delay);
  77
  78         of_property_read_u32(np, "regulator-valid-modes-mask",
  79                                         &constraints->valid_modes_mask);
  80         if (constraints->valid_modes_mask)
  81                 constraints->valid_ops_mask |=  REGULATOR_CHANGE_MODE;
  82
  83         of_property_read_u32(np, "regulator-input-uv",
  84                                         &constraints->input_uV);
  85         of_property_read_u32(np, "regulator-initial-mode",
  86                                         &constraints->initial_mode);
  87         of_property_read_u32(np, "regulator-initial-state",
  88                                         &constraints->initial_state);
  89
  90         /* regulator state during low power system states */
  91         state = of_find_node_by_name(np, "regulator-state-mem");
  92         if (state)
  93                 set_regulator_state_constraints(state,
  94                                 &constraints->state_mem);
  95
  96         state = of_find_node_by_name(np, "regulator-state-disk");
  97         if (state)
  98                 set_regulator_state_constraints(state,
  99                                 &constraints->state_disk);
 100
 101         state = of_find_node_by_name(np, "regulator-state-standby");
 102         if (state)
 103                 set_regulator_state_constraints(state,
 104                                 &constraints->state_standby);
 105
 106
 107 }
 108
 109 /**
 110  * of_get_regulator_init_data - extract regulator_init_data structure info
 111  * @dev: device requesting for regulator_init_data
 112  *
 113  * Populates regulator_init_data structure by extracting data from device
 114  * tree node, returns a pointer to the populated struture or NULL if memory
 115  * alloc fails.
 116  */
 117 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 118                                                 struct device_node *node)
 119 {
 120         struct regulator_init_data *init_data;
 121
 122         if (!node)
 123                 return NULL;
 124
 125         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 126         if (!init_data)
 127                 return NULL; /* Out of memory? */
 128
 129         of_get_regulation_constraints(node, &init_data);
 130         return init_data;
 131 }
 132 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 133
 134 /**
 135  * of_regulator_match - extract multiple regulator init data from device tree.
 136  * @dev: device requesting the data
 137  * @node: parent device node of the regulators
 138  * @matches: match table for the regulators
 139  * @num_matches: number of entries in match table
 140  *
 141  * This function uses a match table specified by the regulator driver to
 142  * parse regulator init data from the device tree. @node is expected to
 143  * contain a set of child nodes, each providing the init data for one
 144  * regulator. The data parsed from a child node will be matched to a regulator
 145  * based on either the deprecated property regulator-compatible if present,
 146  * or otherwise the child node's name. Note that the match table is modified
 147  * in place.
 148  *
 149  * Returns the number of matches found or a negative error code on failure.
 150  */
 151 int of_regulator_match(struct device *dev, struct device_node *node,
 152                        struct of_regulator_match *matches,
 153                        unsigned int num_matches)
 154 {
 155         unsigned int count = 0;
 156         unsigned int i;
 157         const char *name;
 158         struct device_node *child;
 159
 160         if (!dev || !node)
 161                 return -EINVAL;
 162
 163         for (i = 0; i < num_matches; i++) {
 164                 struct of_regulator_match *match = &matches[i];
 165                 match->init_data = NULL;
 166                 match->of_node = NULL;
 167         }
 168
 169         for_each_child_of_node(node, child) {
 170                 name = of_get_property(child,
 171                                         "regulator-compatible", NULL);
 172                 if (!name)
 173                         name = child->name;
 174                 for (i = 0; i < num_matches; i++) {
 175                         struct of_regulator_match *match = &matches[i];
 176                         if (match->of_node)
 177                                 continue;
 178
 179                         if (strcmp(match->name, name))
 180                                 continue;
 181
 182                         match->init_data =
 183                                 of_get_regulator_init_data(dev, child);
 184                         if (!match->init_data) {
 185                                 dev_err(dev,
 186                                         "failed to parse DT for regulator %s\n",
 187                                         child->name);
 188                                 return -EINVAL;
 189                         }
 190                         match->of_node = child;
 191                         count++;
 192                         break;
 193                 }
 194         }
 195
 196         return count;
 197 }
 198 EXPORT_SYMBOL_GPL(of_regulator_match);