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 int ret; 27 u32 pval; 28 29 constraints->name = of_get_property(np, "regulator-name", NULL); 30 31 min_uV = of_get_property(np, "regulator-min-microvolt", NULL); 32 if (min_uV) 33 constraints->min_uV = be32_to_cpu(*min_uV); 34 max_uV = of_get_property(np, "regulator-max-microvolt", NULL); 35 if (max_uV) 36 constraints->max_uV = be32_to_cpu(*max_uV); 37 38 /* Voltage change possible? */ 39 if (constraints->min_uV != constraints->max_uV) 40 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE; 41 /* Only one voltage? Then make sure it's set. */ 42 if (min_uV && max_uV && constraints->min_uV == constraints->max_uV) 43 constraints->apply_uV = true; 44 45 uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL); 46 if (uV_offset) 47 constraints->uV_offset = be32_to_cpu(*uV_offset); 48 min_uA = of_get_property(np, "regulator-min-microamp", NULL); 49 if (min_uA) 50 constraints->min_uA = be32_to_cpu(*min_uA); 51 max_uA = of_get_property(np, "regulator-max-microamp", NULL); 52 if (max_uA) 53 constraints->max_uA = be32_to_cpu(*max_uA); 54 55 /* Current change possible? */ 56 if (constraints->min_uA != constraints->max_uA) 57 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT; 58 59 if (of_find_property(np, "regulator-boot-on", NULL)) 60 constraints->boot_on = true; 61 62 if (of_find_property(np, "regulator-always-on", NULL)) 63 constraints->always_on = true; 64 else /* status change should be possible if not always on. */ 65 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS; 66 67 if (of_property_read_bool(np, "regulator-allow-bypass")) 68 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS; 69 70 prop = of_find_property(np, "regulator-ramp-delay", NULL); 71 if (prop && prop->value) { 72 ramp_delay = prop->value; 73 if (*ramp_delay) 74 constraints->ramp_delay = be32_to_cpu(*ramp_delay); 75 else 76 constraints->ramp_disable = true; 77 } 78 79 ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval); 80 if (!ret) 81 constraints->enable_time = pval; 82 } 83 84 /** 85 * of_get_regulator_init_data - extract regulator_init_data structure info 86 * @dev: device requesting for regulator_init_data 87 * 88 * Populates regulator_init_data structure by extracting data from device 89 * tree node, returns a pointer to the populated struture or NULL if memory 90 * alloc fails. 91 */ 92 struct regulator_init_data *of_get_regulator_init_data(struct device *dev, 93 struct device_node *node) 94 { 95 struct regulator_init_data *init_data; 96 97 if (!node) 98 return NULL; 99 100 init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL); 101 if (!init_data) 102 return NULL; /* Out of memory? */ 103 104 of_get_regulation_constraints(node, &init_data); 105 return init_data; 106 } 107 EXPORT_SYMBOL_GPL(of_get_regulator_init_data); 108 109 /** 110 * of_regulator_match - extract multiple regulator init data from device tree. 111 * @dev: device requesting the data 112 * @node: parent device node of the regulators 113 * @matches: match table for the regulators 114 * @num_matches: number of entries in match table 115 * 116 * This function uses a match table specified by the regulator driver to 117 * parse regulator init data from the device tree. @node is expected to 118 * contain a set of child nodes, each providing the init data for one 119 * regulator. The data parsed from a child node will be matched to a regulator 120 * based on either the deprecated property regulator-compatible if present, 121 * or otherwise the child node's name. Note that the match table is modified 122 * in place. 123 * 124 * Returns the number of matches found or a negative error code on failure. 125 */ 126 int of_regulator_match(struct device *dev, struct device_node *node, 127 struct of_regulator_match *matches, 128 unsigned int num_matches) 129 { 130 unsigned int count = 0; 131 unsigned int i; 132 const char *name; 133 struct device_node *child; 134 135 if (!dev || !node) 136 return -EINVAL; 137 138 for (i = 0; i < num_matches; i++) { 139 struct of_regulator_match *match = &matches[i]; 140 match->init_data = NULL; 141 match->of_node = NULL; 142 } 143 144 for_each_child_of_node(node, child) { 145 name = of_get_property(child, 146 "regulator-compatible", NULL); 147 if (!name) 148 name = child->name; 149 for (i = 0; i < num_matches; i++) { 150 struct of_regulator_match *match = &matches[i]; 151 if (match->of_node) 152 continue; 153 154 if (strcmp(match->name, name)) 155 continue; 156 157 match->init_data = 158 of_get_regulator_init_data(dev, child); 159 if (!match->init_data) { 160 dev_err(dev, 161 "failed to parse DT for regulator %s\n", 162 child->name); 163 return -EINVAL; 164 } 165 match->of_node = child; 166 count++; 167 break; 168 } 169 } 170 171 return count; 172 } 173 EXPORT_SYMBOL_GPL(of_regulator_match); 174