1 // SPDX-License-Identifier: GPL-2.0 2 // 3 // Register map access API - I2C support 4 // 5 // Copyright 2011 Wolfson Microelectronics plc 6 // 7 // Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 8 9 #include <linux/regmap.h> 10 #include <linux/i2c.h> 11 #include <linux/module.h> 12 13 #include "internal.h" 14 15 static int regmap_smbus_byte_reg_read(void *context, unsigned int reg, 16 unsigned int *val) 17 { 18 struct device *dev = context; 19 struct i2c_client *i2c = to_i2c_client(dev); 20 int ret; 21 22 if (reg > 0xff) 23 return -EINVAL; 24 25 ret = i2c_smbus_read_byte_data(i2c, reg); 26 if (ret < 0) 27 return ret; 28 29 *val = ret; 30 31 return 0; 32 } 33 34 static int regmap_smbus_byte_reg_write(void *context, unsigned int reg, 35 unsigned int val) 36 { 37 struct device *dev = context; 38 struct i2c_client *i2c = to_i2c_client(dev); 39 40 if (val > 0xff || reg > 0xff) 41 return -EINVAL; 42 43 return i2c_smbus_write_byte_data(i2c, reg, val); 44 } 45 46 static const struct regmap_bus regmap_smbus_byte = { 47 .reg_write = regmap_smbus_byte_reg_write, 48 .reg_read = regmap_smbus_byte_reg_read, 49 }; 50 51 static int regmap_smbus_word_reg_read(void *context, unsigned int reg, 52 unsigned int *val) 53 { 54 struct device *dev = context; 55 struct i2c_client *i2c = to_i2c_client(dev); 56 int ret; 57 58 if (reg > 0xff) 59 return -EINVAL; 60 61 ret = i2c_smbus_read_word_data(i2c, reg); 62 if (ret < 0) 63 return ret; 64 65 *val = ret; 66 67 return 0; 68 } 69 70 static int regmap_smbus_word_reg_write(void *context, unsigned int reg, 71 unsigned int val) 72 { 73 struct device *dev = context; 74 struct i2c_client *i2c = to_i2c_client(dev); 75 76 if (val > 0xffff || reg > 0xff) 77 return -EINVAL; 78 79 return i2c_smbus_write_word_data(i2c, reg, val); 80 } 81 82 static const struct regmap_bus regmap_smbus_word = { 83 .reg_write = regmap_smbus_word_reg_write, 84 .reg_read = regmap_smbus_word_reg_read, 85 }; 86 87 static int regmap_smbus_word_read_swapped(void *context, unsigned int reg, 88 unsigned int *val) 89 { 90 struct device *dev = context; 91 struct i2c_client *i2c = to_i2c_client(dev); 92 int ret; 93 94 if (reg > 0xff) 95 return -EINVAL; 96 97 ret = i2c_smbus_read_word_swapped(i2c, reg); 98 if (ret < 0) 99 return ret; 100 101 *val = ret; 102 103 return 0; 104 } 105 106 static int regmap_smbus_word_write_swapped(void *context, unsigned int reg, 107 unsigned int val) 108 { 109 struct device *dev = context; 110 struct i2c_client *i2c = to_i2c_client(dev); 111 112 if (val > 0xffff || reg > 0xff) 113 return -EINVAL; 114 115 return i2c_smbus_write_word_swapped(i2c, reg, val); 116 } 117 118 static const struct regmap_bus regmap_smbus_word_swapped = { 119 .reg_write = regmap_smbus_word_write_swapped, 120 .reg_read = regmap_smbus_word_read_swapped, 121 }; 122 123 static int regmap_i2c_write(void *context, const void *data, size_t count) 124 { 125 struct device *dev = context; 126 struct i2c_client *i2c = to_i2c_client(dev); 127 int ret; 128 129 ret = i2c_master_send(i2c, data, count); 130 if (ret == count) 131 return 0; 132 else if (ret < 0) 133 return ret; 134 else 135 return -EIO; 136 } 137 138 static int regmap_i2c_gather_write(void *context, 139 const void *reg, size_t reg_size, 140 const void *val, size_t val_size) 141 { 142 struct device *dev = context; 143 struct i2c_client *i2c = to_i2c_client(dev); 144 struct i2c_msg xfer[2]; 145 int ret; 146 147 /* If the I2C controller can't do a gather tell the core, it 148 * will substitute in a linear write for us. 149 */ 150 if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_NOSTART)) 151 return -ENOTSUPP; 152 153 xfer[0].addr = i2c->addr; 154 xfer[0].flags = 0; 155 xfer[0].len = reg_size; 156 xfer[0].buf = (void *)reg; 157 158 xfer[1].addr = i2c->addr; 159 xfer[1].flags = I2C_M_NOSTART; 160 xfer[1].len = val_size; 161 xfer[1].buf = (void *)val; 162 163 ret = i2c_transfer(i2c->adapter, xfer, 2); 164 if (ret == 2) 165 return 0; 166 if (ret < 0) 167 return ret; 168 else 169 return -EIO; 170 } 171 172 static int regmap_i2c_read(void *context, 173 const void *reg, size_t reg_size, 174 void *val, size_t val_size) 175 { 176 struct device *dev = context; 177 struct i2c_client *i2c = to_i2c_client(dev); 178 struct i2c_msg xfer[2]; 179 int ret; 180 181 xfer[0].addr = i2c->addr; 182 xfer[0].flags = 0; 183 xfer[0].len = reg_size; 184 xfer[0].buf = (void *)reg; 185 186 xfer[1].addr = i2c->addr; 187 xfer[1].flags = I2C_M_RD; 188 xfer[1].len = val_size; 189 xfer[1].buf = val; 190 191 ret = i2c_transfer(i2c->adapter, xfer, 2); 192 if (ret == 2) 193 return 0; 194 else if (ret < 0) 195 return ret; 196 else 197 return -EIO; 198 } 199 200 static const struct regmap_bus regmap_i2c = { 201 .write = regmap_i2c_write, 202 .gather_write = regmap_i2c_gather_write, 203 .read = regmap_i2c_read, 204 .reg_format_endian_default = REGMAP_ENDIAN_BIG, 205 .val_format_endian_default = REGMAP_ENDIAN_BIG, 206 }; 207 208 static int regmap_i2c_smbus_i2c_write(void *context, const void *data, 209 size_t count) 210 { 211 struct device *dev = context; 212 struct i2c_client *i2c = to_i2c_client(dev); 213 214 if (count < 1) 215 return -EINVAL; 216 217 --count; 218 return i2c_smbus_write_i2c_block_data(i2c, ((u8 *)data)[0], count, 219 ((u8 *)data + 1)); 220 } 221 222 static int regmap_i2c_smbus_i2c_read(void *context, const void *reg, 223 size_t reg_size, void *val, 224 size_t val_size) 225 { 226 struct device *dev = context; 227 struct i2c_client *i2c = to_i2c_client(dev); 228 int ret; 229 230 if (reg_size != 1 || val_size < 1) 231 return -EINVAL; 232 233 ret = i2c_smbus_read_i2c_block_data(i2c, ((u8 *)reg)[0], val_size, val); 234 if (ret == val_size) 235 return 0; 236 else if (ret < 0) 237 return ret; 238 else 239 return -EIO; 240 } 241 242 static const struct regmap_bus regmap_i2c_smbus_i2c_block = { 243 .write = regmap_i2c_smbus_i2c_write, 244 .read = regmap_i2c_smbus_i2c_read, 245 .max_raw_read = I2C_SMBUS_BLOCK_MAX, 246 .max_raw_write = I2C_SMBUS_BLOCK_MAX, 247 }; 248 249 static int regmap_i2c_smbus_i2c_write_reg16(void *context, const void *data, 250 size_t count) 251 { 252 struct device *dev = context; 253 struct i2c_client *i2c = to_i2c_client(dev); 254 255 if (count < 2) 256 return -EINVAL; 257 258 count--; 259 return i2c_smbus_write_i2c_block_data(i2c, ((u8 *)data)[0], count, 260 (u8 *)data + 1); 261 } 262 263 static int regmap_i2c_smbus_i2c_read_reg16(void *context, const void *reg, 264 size_t reg_size, void *val, 265 size_t val_size) 266 { 267 struct device *dev = context; 268 struct i2c_client *i2c = to_i2c_client(dev); 269 int ret, count, len = val_size; 270 271 if (reg_size != 2) 272 return -EINVAL; 273 274 ret = i2c_smbus_write_byte_data(i2c, ((u16 *)reg)[0] & 0xff, 275 ((u16 *)reg)[0] >> 8); 276 if (ret < 0) 277 return ret; 278 279 count = 0; 280 do { 281 /* Current Address Read */ 282 ret = i2c_smbus_read_byte(i2c); 283 if (ret < 0) 284 break; 285 286 *((u8 *)val++) = ret; 287 count++; 288 len--; 289 } while (len > 0); 290 291 if (count == val_size) 292 return 0; 293 else if (ret < 0) 294 return ret; 295 else 296 return -EIO; 297 } 298 299 static const struct regmap_bus regmap_i2c_smbus_i2c_block_reg16 = { 300 .write = regmap_i2c_smbus_i2c_write_reg16, 301 .read = regmap_i2c_smbus_i2c_read_reg16, 302 .max_raw_read = I2C_SMBUS_BLOCK_MAX, 303 .max_raw_write = I2C_SMBUS_BLOCK_MAX, 304 }; 305 306 static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c, 307 const struct regmap_config *config) 308 { 309 const struct i2c_adapter_quirks *quirks; 310 const struct regmap_bus *bus = NULL; 311 struct regmap_bus *ret_bus; 312 u16 max_read = 0, max_write = 0; 313 314 if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C)) 315 bus = ®map_i2c; 316 else if (config->val_bits == 8 && config->reg_bits == 8 && 317 i2c_check_functionality(i2c->adapter, 318 I2C_FUNC_SMBUS_I2C_BLOCK)) 319 bus = ®map_i2c_smbus_i2c_block; 320 else if (config->val_bits == 8 && config->reg_bits == 16 && 321 i2c_check_functionality(i2c->adapter, 322 I2C_FUNC_SMBUS_I2C_BLOCK)) 323 bus = ®map_i2c_smbus_i2c_block_reg16; 324 else if (config->val_bits == 16 && config->reg_bits == 8 && 325 i2c_check_functionality(i2c->adapter, 326 I2C_FUNC_SMBUS_WORD_DATA)) 327 switch (regmap_get_val_endian(&i2c->dev, NULL, config)) { 328 case REGMAP_ENDIAN_LITTLE: 329 bus = ®map_smbus_word; 330 break; 331 case REGMAP_ENDIAN_BIG: 332 bus = ®map_smbus_word_swapped; 333 break; 334 default: /* everything else is not supported */ 335 break; 336 } 337 else if (config->val_bits == 8 && config->reg_bits == 8 && 338 i2c_check_functionality(i2c->adapter, 339 I2C_FUNC_SMBUS_BYTE_DATA)) 340 bus = ®map_smbus_byte; 341 342 if (!bus) 343 return ERR_PTR(-ENOTSUPP); 344 345 quirks = i2c->adapter->quirks; 346 if (quirks) { 347 if (quirks->max_read_len && 348 (bus->max_raw_read == 0 || bus->max_raw_read > quirks->max_read_len)) 349 max_read = quirks->max_read_len; 350 351 if (quirks->max_write_len && 352 (bus->max_raw_write == 0 || bus->max_raw_write > quirks->max_write_len)) 353 max_write = quirks->max_write_len; 354 355 if (max_read || max_write) { 356 ret_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL); 357 if (!ret_bus) 358 return ERR_PTR(-ENOMEM); 359 ret_bus->free_on_exit = true; 360 ret_bus->max_raw_read = max_read; 361 ret_bus->max_raw_write = max_write; 362 bus = ret_bus; 363 } 364 } 365 366 return bus; 367 } 368 369 struct regmap *__regmap_init_i2c(struct i2c_client *i2c, 370 const struct regmap_config *config, 371 struct lock_class_key *lock_key, 372 const char *lock_name) 373 { 374 const struct regmap_bus *bus = regmap_get_i2c_bus(i2c, config); 375 376 if (IS_ERR(bus)) 377 return ERR_CAST(bus); 378 379 return __regmap_init(&i2c->dev, bus, &i2c->dev, config, 380 lock_key, lock_name); 381 } 382 EXPORT_SYMBOL_GPL(__regmap_init_i2c); 383 384 struct regmap *__devm_regmap_init_i2c(struct i2c_client *i2c, 385 const struct regmap_config *config, 386 struct lock_class_key *lock_key, 387 const char *lock_name) 388 { 389 const struct regmap_bus *bus = regmap_get_i2c_bus(i2c, config); 390 391 if (IS_ERR(bus)) 392 return ERR_CAST(bus); 393 394 return __devm_regmap_init(&i2c->dev, bus, &i2c->dev, config, 395 lock_key, lock_name); 396 } 397 EXPORT_SYMBOL_GPL(__devm_regmap_init_i2c); 398 399 MODULE_LICENSE("GPL"); 400