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 ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL); 65 if (ramp_delay) 66 constraints->ramp_delay = be32_to_cpu(*ramp_delay); 67 } 68 69 /** 70 * of_get_regulator_init_data - extract regulator_init_data structure info 71 * @dev: device requesting for regulator_init_data 72 * 73 * Populates regulator_init_data structure by extracting data from device 74 * tree node, returns a pointer to the populated struture or NULL if memory 75 * alloc fails. 76 */ 77 struct regulator_init_data *of_get_regulator_init_data(struct device *dev, 78 struct device_node *node) 79 { 80 struct regulator_init_data *init_data; 81 82 if (!node) 83 return NULL; 84 85 init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL); 86 if (!init_data) 87 return NULL; /* Out of memory? */ 88 89 of_get_regulation_constraints(node, &init_data); 90 return init_data; 91 } 92 EXPORT_SYMBOL_GPL(of_get_regulator_init_data); 93 94 /** 95 * of_regulator_match - extract multiple regulator init data from device tree. 96 * @dev: device requesting the data 97 * @node: parent device node of the regulators 98 * @matches: match table for the regulators 99 * @num_matches: number of entries in match table 100 * 101 * This function uses a match table specified by the regulator driver to 102 * parse regulator init data from the device tree. @node is expected to 103 * contain a set of child nodes, each providing the init data for one 104 * regulator. The data parsed from a child node will be matched to a regulator 105 * based on either the deprecated property regulator-compatible if present, 106 * or otherwise the child node's name. Note that the match table is modified 107 * in place. 108 * 109 * Returns the number of matches found or a negative error code on failure. 110 */ 111 int of_regulator_match(struct device *dev, struct device_node *node, 112 struct of_regulator_match *matches, 113 unsigned int num_matches) 114 { 115 unsigned int count = 0; 116 unsigned int i; 117 const char *name; 118 struct device_node *child; 119 120 if (!dev || !node) 121 return -EINVAL; 122 123 for (i = 0; i < num_matches; i++) { 124 struct of_regulator_match *match = &matches[i]; 125 match->init_data = NULL; 126 match->of_node = NULL; 127 } 128 129 for_each_child_of_node(node, child) { 130 name = of_get_property(child, 131 "regulator-compatible", NULL); 132 if (!name) 133 name = child->name; 134 for (i = 0; i < num_matches; i++) { 135 struct of_regulator_match *match = &matches[i]; 136 if (match->of_node) 137 continue; 138 139 if (strcmp(match->name, name)) 140 continue; 141 142 match->init_data = 143 of_get_regulator_init_data(dev, child); 144 if (!match->init_data) { 145 dev_err(dev, 146 "failed to parse DT for regulator %s\n", 147 child->name); 148 return -EINVAL; 149 } 150 match->of_node = child; 151 count++; 152 break; 153 } 154 } 155 156 return count; 157 } 158 EXPORT_SYMBOL_GPL(of_regulator_match); 159