1 // SPDX-License-Identifier: GPL-2.0 2 // 3 // Register cache access API - flat caching support 4 // 5 // Copyright 2012 Wolfson Microelectronics plc 6 // 7 // Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 8 9 #include <linux/bitmap.h> 10 #include <linux/bitops.h> 11 #include <linux/device.h> 12 #include <linux/limits.h> 13 #include <linux/overflow.h> 14 #include <linux/seq_file.h> 15 #include <linux/slab.h> 16 17 #include "internal.h" 18 19 static inline unsigned int regcache_flat_get_index(const struct regmap *map, 20 unsigned int reg) 21 { 22 return regcache_get_index_by_order(map, reg); 23 } 24 25 struct regcache_flat_data { 26 unsigned long *valid; 27 unsigned int data[]; 28 }; 29 30 static int regcache_flat_init(struct regmap *map) 31 { 32 unsigned int cache_size; 33 struct regcache_flat_data *cache; 34 35 if (!map || map->reg_stride_order < 0 || !map->max_register_is_set) 36 return -EINVAL; 37 38 cache_size = regcache_flat_get_index(map, map->max_register) + 1; 39 cache = kzalloc_flex(*cache, data, cache_size, map->alloc_flags); 40 if (!cache) 41 return -ENOMEM; 42 43 cache->valid = bitmap_zalloc(cache_size, map->alloc_flags); 44 if (!cache->valid) 45 goto err_free; 46 47 map->cache = cache; 48 49 return 0; 50 51 err_free: 52 kfree(cache); 53 return -ENOMEM; 54 } 55 56 static void regcache_flat_exit(struct regmap *map) 57 { 58 struct regcache_flat_data *cache = map->cache; 59 60 if (cache) 61 bitmap_free(cache->valid); 62 63 kfree(cache); 64 map->cache = NULL; 65 } 66 67 static int regcache_flat_populate(struct regmap *map) 68 { 69 struct regcache_flat_data *cache = map->cache; 70 unsigned int i; 71 72 for (i = 0; i < map->num_reg_defaults; i++) { 73 unsigned int reg = map->reg_defaults[i].reg; 74 unsigned int index = regcache_flat_get_index(map, reg); 75 76 cache->data[index] = map->reg_defaults[i].def; 77 __set_bit(index, cache->valid); 78 } 79 80 if (map->reg_default_cb) { 81 dev_dbg(map->dev, 82 "Populating regcache_flat using reg_default_cb callback\n"); 83 84 for (i = 0; i <= map->max_register; i += map->reg_stride) { 85 unsigned int index = regcache_flat_get_index(map, i); 86 unsigned int value; 87 88 if (test_bit(index, cache->valid)) 89 continue; 90 91 if (map->reg_default_cb(map->dev, i, &value)) 92 continue; 93 94 cache->data[index] = value; 95 __set_bit(index, cache->valid); 96 } 97 } 98 99 return 0; 100 } 101 102 static int regcache_flat_read(struct regmap *map, 103 unsigned int reg, unsigned int *value) 104 { 105 struct regcache_flat_data *cache = map->cache; 106 unsigned int index = regcache_flat_get_index(map, reg); 107 108 /* legacy behavior: ignore validity, but warn the user */ 109 if (unlikely(!test_bit(index, cache->valid))) 110 dev_warn_once(map->dev, 111 "using zero-initialized flat cache, this may cause unexpected behavior"); 112 113 *value = cache->data[index]; 114 115 return 0; 116 } 117 118 static int regcache_flat_sparse_read(struct regmap *map, 119 unsigned int reg, unsigned int *value) 120 { 121 struct regcache_flat_data *cache = map->cache; 122 unsigned int index = regcache_flat_get_index(map, reg); 123 124 if (unlikely(!test_bit(index, cache->valid))) 125 return -ENOENT; 126 127 *value = cache->data[index]; 128 129 return 0; 130 } 131 132 static int regcache_flat_write(struct regmap *map, unsigned int reg, 133 unsigned int value) 134 { 135 struct regcache_flat_data *cache = map->cache; 136 unsigned int index = regcache_flat_get_index(map, reg); 137 138 cache->data[index] = value; 139 __set_bit(index, cache->valid); 140 141 return 0; 142 } 143 144 static int regcache_flat_drop(struct regmap *map, unsigned int min, 145 unsigned int max) 146 { 147 struct regcache_flat_data *cache = map->cache; 148 unsigned int bitmap_min = regcache_flat_get_index(map, min); 149 unsigned int bitmap_max = regcache_flat_get_index(map, max); 150 151 bitmap_clear(cache->valid, bitmap_min, bitmap_max + 1 - bitmap_min); 152 153 return 0; 154 } 155 156 struct regcache_ops regcache_flat_ops = { 157 .type = REGCACHE_FLAT, 158 .name = "flat", 159 .init = regcache_flat_init, 160 .exit = regcache_flat_exit, 161 .populate = regcache_flat_populate, 162 .read = regcache_flat_read, 163 .write = regcache_flat_write, 164 }; 165 166 struct regcache_ops regcache_flat_sparse_ops = { 167 .type = REGCACHE_FLAT_S, 168 .name = "flat-sparse", 169 .init = regcache_flat_init, 170 .exit = regcache_flat_exit, 171 .populate = regcache_flat_populate, 172 .read = regcache_flat_sparse_read, 173 .write = regcache_flat_write, 174 .drop = regcache_flat_drop, 175 }; 176