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 void of_get_regulation_constraints(struct device_node *np, 23 struct regulator_init_data **init_data) 24 { 25 const __be32 *min_uV, *max_uV; 26 struct regulation_constraints *constraints = &(*init_data)->constraints; 27 int ret; 28 u32 pval; 29 30 constraints->name = of_get_property(np, "regulator-name", NULL); 31 32 min_uV = of_get_property(np, "regulator-min-microvolt", NULL); 33 if (min_uV) 34 constraints->min_uV = be32_to_cpu(*min_uV); 35 max_uV = of_get_property(np, "regulator-max-microvolt", NULL); 36 if (max_uV) 37 constraints->max_uV = be32_to_cpu(*max_uV); 38 39 /* Voltage change possible? */ 40 if (constraints->min_uV != constraints->max_uV) 41 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE; 42 /* Only one voltage? Then make sure it's set. */ 43 if (min_uV && max_uV && constraints->min_uV == constraints->max_uV) 44 constraints->apply_uV = true; 45 46 if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval)) 47 constraints->uV_offset = pval; 48 if (!of_property_read_u32(np, "regulator-min-microamp", &pval)) 49 constraints->min_uA = pval; 50 if (!of_property_read_u32(np, "regulator-max-microamp", &pval)) 51 constraints->max_uA = pval; 52 53 /* Current change possible? */ 54 if (constraints->min_uA != constraints->max_uA) 55 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT; 56 57 constraints->boot_on = of_property_read_bool(np, "regulator-boot-on"); 58 constraints->always_on = of_property_read_bool(np, "regulator-always-on"); 59 if (!constraints->always_on) /* status change should be possible. */ 60 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS; 61 62 if (of_property_read_bool(np, "regulator-allow-bypass")) 63 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS; 64 65 ret = of_property_read_u32(np, "regulator-ramp-delay", &pval); 66 if (!ret) { 67 if (pval) 68 constraints->ramp_delay = pval; 69 else 70 constraints->ramp_disable = true; 71 } 72 73 ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval); 74 if (!ret) 75 constraints->enable_time = pval; 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 struct devm_of_regulator_matches { 104 struct of_regulator_match *matches; 105 unsigned int num_matches; 106 }; 107 108 static void devm_of_regulator_put_matches(struct device *dev, void *res) 109 { 110 struct devm_of_regulator_matches *devm_matches = res; 111 int i; 112 113 for (i = 0; i < devm_matches->num_matches; i++) 114 of_node_put(devm_matches->matches[i].of_node); 115 } 116 117 /** 118 * of_regulator_match - extract multiple regulator init data from device tree. 119 * @dev: device requesting the data 120 * @node: parent device node of the regulators 121 * @matches: match table for the regulators 122 * @num_matches: number of entries in match table 123 * 124 * This function uses a match table specified by the regulator driver to 125 * parse regulator init data from the device tree. @node is expected to 126 * contain a set of child nodes, each providing the init data for one 127 * regulator. The data parsed from a child node will be matched to a regulator 128 * based on either the deprecated property regulator-compatible if present, 129 * or otherwise the child node's name. Note that the match table is modified 130 * in place and an additional of_node reference is taken for each matched 131 * regulator. 132 * 133 * Returns the number of matches found or a negative error code on failure. 134 */ 135 int of_regulator_match(struct device *dev, struct device_node *node, 136 struct of_regulator_match *matches, 137 unsigned int num_matches) 138 { 139 unsigned int count = 0; 140 unsigned int i; 141 const char *name; 142 struct device_node *child; 143 struct devm_of_regulator_matches *devm_matches; 144 145 if (!dev || !node) 146 return -EINVAL; 147 148 devm_matches = devres_alloc(devm_of_regulator_put_matches, 149 sizeof(struct devm_of_regulator_matches), 150 GFP_KERNEL); 151 if (!devm_matches) 152 return -ENOMEM; 153 154 devm_matches->matches = matches; 155 devm_matches->num_matches = num_matches; 156 157 devres_add(dev, devm_matches); 158 159 for (i = 0; i < num_matches; i++) { 160 struct of_regulator_match *match = &matches[i]; 161 match->init_data = NULL; 162 match->of_node = NULL; 163 } 164 165 for_each_child_of_node(node, child) { 166 name = of_get_property(child, 167 "regulator-compatible", NULL); 168 if (!name) 169 name = child->name; 170 for (i = 0; i < num_matches; i++) { 171 struct of_regulator_match *match = &matches[i]; 172 if (match->of_node) 173 continue; 174 175 if (strcmp(match->name, name)) 176 continue; 177 178 match->init_data = 179 of_get_regulator_init_data(dev, child); 180 if (!match->init_data) { 181 dev_err(dev, 182 "failed to parse DT for regulator %s\n", 183 child->name); 184 return -EINVAL; 185 } 186 match->of_node = of_node_get(child); 187 count++; 188 break; 189 } 190 } 191 192 return count; 193 } 194 EXPORT_SYMBOL_GPL(of_regulator_match); 195 196 struct regulator_init_data *regulator_of_get_init_data(struct device *dev, 197 const struct regulator_desc *desc, 198 struct device_node **node) 199 { 200 struct device_node *search, *child; 201 struct regulator_init_data *init_data = NULL; 202 const char *name; 203 204 if (!dev->of_node || !desc->of_match) 205 return NULL; 206 207 if (desc->regulators_node) 208 search = of_get_child_by_name(dev->of_node, 209 desc->regulators_node); 210 else 211 search = dev->of_node; 212 213 if (!search) { 214 dev_err(dev, "Failed to find regulator container node\n"); 215 return NULL; 216 } 217 218 for_each_child_of_node(search, child) { 219 name = of_get_property(child, "regulator-compatible", NULL); 220 if (!name) 221 name = child->name; 222 223 if (strcmp(desc->of_match, name)) 224 continue; 225 226 init_data = of_get_regulator_init_data(dev, child); 227 if (!init_data) { 228 dev_err(dev, 229 "failed to parse DT for regulator %s\n", 230 child->name); 231 break; 232 } 233 234 of_node_get(child); 235 *node = child; 236 break; 237 } 238 239 of_node_put(search); 240 241 return init_data; 242 } 243