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