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