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; 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 65 /** 66 * of_get_regulator_init_data - extract regulator_init_data structure info 67 * @dev: device requesting for regulator_init_data 68 * 69 * Populates regulator_init_data structure by extracting data from device 70 * tree node, returns a pointer to the populated struture or NULL if memory 71 * alloc fails. 72 */ 73 struct regulator_init_data *of_get_regulator_init_data(struct device *dev, 74 struct device_node *node) 75 { 76 struct regulator_init_data *init_data; 77 78 if (!node) 79 return NULL; 80 81 init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL); 82 if (!init_data) 83 return NULL; /* Out of memory? */ 84 85 of_get_regulation_constraints(node, &init_data); 86 return init_data; 87 } 88 EXPORT_SYMBOL_GPL(of_get_regulator_init_data); 89 90 /** 91 * of_regulator_match - extract regulator init data 92 * @dev: device requesting the data 93 * @node: parent device node of the regulators 94 * @matches: match table for the regulators 95 * @num_matches: number of entries in match table 96 * 97 * This function uses a match table specified by the regulator driver and 98 * looks up the corresponding init data in the device tree. Note that the 99 * match table is modified in place. 100 * 101 * Returns the number of matches found or a negative error code on failure. 102 */ 103 int of_regulator_match(struct device *dev, struct device_node *node, 104 struct of_regulator_match *matches, 105 unsigned int num_matches) 106 { 107 unsigned int count = 0; 108 unsigned int i; 109 110 if (!dev || !node) 111 return -EINVAL; 112 113 for (i = 0; i < num_matches; i++) { 114 struct of_regulator_match *match = &matches[i]; 115 struct device_node *child; 116 117 child = of_find_node_by_name(node, match->name); 118 if (!child) 119 continue; 120 121 match->init_data = of_get_regulator_init_data(dev, child); 122 if (!match->init_data) { 123 dev_err(dev, "failed to parse DT for regulator %s\n", 124 child->name); 125 return -EINVAL; 126 } 127 128 match->of_node = child; 129 count++; 130 } 131 132 return count; 133 } 134 EXPORT_SYMBOL_GPL(of_regulator_match); 135