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 regulator init data when node 96 * property "regulator-compatible" matches with the regulator name. 97 * @dev: device requesting the data 98 * @node: parent device node of the regulators 99 * @matches: match table for the regulators 100 * @num_matches: number of entries in match table 101 * 102 * This function uses a match table specified by the regulator driver and 103 * looks up the corresponding init data in the device tree if 104 * regulator-compatible matches. Note that the match table is modified 105 * in place. 106 * 107 * Returns the number of matches found or a negative error code on failure. 108 */ 109 int of_regulator_match(struct device *dev, struct device_node *node, 110 struct of_regulator_match *matches, 111 unsigned int num_matches) 112 { 113 unsigned int count = 0; 114 unsigned int i; 115 const char *regulator_comp; 116 struct device_node *child; 117 118 if (!dev || !node) 119 return -EINVAL; 120 121 for_each_child_of_node(node, child) { 122 regulator_comp = of_get_property(child, 123 "regulator-compatible", NULL); 124 if (!regulator_comp) { 125 dev_err(dev, "regulator-compatible is missing for node %s\n", 126 child->name); 127 continue; 128 } 129 for (i = 0; i < num_matches; i++) { 130 struct of_regulator_match *match = &matches[i]; 131 if (match->of_node) 132 continue; 133 134 if (strcmp(match->name, regulator_comp)) 135 continue; 136 137 match->init_data = 138 of_get_regulator_init_data(dev, child); 139 if (!match->init_data) { 140 dev_err(dev, 141 "failed to parse DT for regulator %s\n", 142 child->name); 143 return -EINVAL; 144 } 145 match->of_node = child; 146 count++; 147 break; 148 } 149 } 150 151 return count; 152 } 153 EXPORT_SYMBOL_GPL(of_regulator_match); 154