1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com> 4 * 5 * The LM95241 is a sensor chip made by National Semiconductors. 6 * It reports up to three temperatures (its own plus up to two external ones). 7 * Complete datasheet can be obtained from National's website at: 8 * http://www.national.com/ds.cgi/LM/LM95241.pdf 9 */ 10 11 #include <linux/bitops.h> 12 #include <linux/err.h> 13 #include <linux/i2c.h> 14 #include <linux/init.h> 15 #include <linux/jiffies.h> 16 #include <linux/hwmon.h> 17 #include <linux/module.h> 18 #include <linux/mutex.h> 19 #include <linux/slab.h> 20 21 #define DEVNAME "lm95241" 22 23 static const unsigned short normal_i2c[] = { 24 0x19, 0x2a, 0x2b, I2C_CLIENT_END }; 25 26 /* LM95241 registers */ 27 #define LM95241_REG_R_MAN_ID 0xFE 28 #define LM95241_REG_R_CHIP_ID 0xFF 29 #define LM95241_REG_R_STATUS 0x02 30 #define LM95241_REG_RW_CONFIG 0x03 31 #define LM95241_REG_RW_REM_FILTER 0x06 32 #define LM95241_REG_RW_TRUTHERM 0x07 33 #define LM95241_REG_W_ONE_SHOT 0x0F 34 #define LM95241_REG_R_LOCAL_TEMPH 0x10 35 #define LM95241_REG_R_REMOTE1_TEMPH 0x11 36 #define LM95241_REG_R_REMOTE2_TEMPH 0x12 37 #define LM95241_REG_R_LOCAL_TEMPL 0x20 38 #define LM95241_REG_R_REMOTE1_TEMPL 0x21 39 #define LM95241_REG_R_REMOTE2_TEMPL 0x22 40 #define LM95241_REG_RW_REMOTE_MODEL 0x30 41 42 /* LM95241 specific bitfields */ 43 #define CFG_STOP BIT(6) 44 #define CFG_CR0076 0x00 45 #define CFG_CR0182 BIT(4) 46 #define CFG_CR1000 BIT(5) 47 #define CFG_CR2700 (BIT(4) | BIT(5)) 48 #define CFG_CRMASK (BIT(4) | BIT(5)) 49 #define R1MS_MASK BIT(0) 50 #define R2MS_MASK BIT(2) 51 #define R1DF_MASK BIT(1) 52 #define R2DF_MASK BIT(2) 53 #define R1FE_MASK BIT(0) 54 #define R2FE_MASK BIT(2) 55 #define R1DM BIT(0) 56 #define R2DM BIT(1) 57 #define TT1_SHIFT 0 58 #define TT2_SHIFT 4 59 #define TT_OFF 0 60 #define TT_ON 1 61 #define TT_MASK 7 62 #define NATSEMI_MAN_ID 0x01 63 #define LM95231_CHIP_ID 0xA1 64 #define LM95241_CHIP_ID 0xA4 65 66 static const u8 lm95241_reg_address[] = { 67 LM95241_REG_R_LOCAL_TEMPH, 68 LM95241_REG_R_LOCAL_TEMPL, 69 LM95241_REG_R_REMOTE1_TEMPH, 70 LM95241_REG_R_REMOTE1_TEMPL, 71 LM95241_REG_R_REMOTE2_TEMPH, 72 LM95241_REG_R_REMOTE2_TEMPL 73 }; 74 75 /* Client data (each client gets its own) */ 76 struct lm95241_data { 77 struct i2c_client *client; 78 struct mutex update_lock; 79 unsigned long last_updated; /* in jiffies */ 80 unsigned long interval; /* in milli-seconds */ 81 bool valid; /* false until following fields are valid */ 82 /* registers values */ 83 u8 temp[ARRAY_SIZE(lm95241_reg_address)]; 84 u8 status, config, model, trutherm; 85 }; 86 87 /* Conversions */ 88 static int temp_from_reg_signed(u8 val_h, u8 val_l) 89 { 90 s16 val_hl = (val_h << 8) | val_l; 91 return val_hl * 1000 / 256; 92 } 93 94 static int temp_from_reg_unsigned(u8 val_h, u8 val_l) 95 { 96 u16 val_hl = (val_h << 8) | val_l; 97 return val_hl * 1000 / 256; 98 } 99 100 static struct lm95241_data *lm95241_update_device(struct device *dev) 101 { 102 struct lm95241_data *data = dev_get_drvdata(dev); 103 struct i2c_client *client = data->client; 104 105 mutex_lock(&data->update_lock); 106 107 if (time_after(jiffies, data->last_updated 108 + msecs_to_jiffies(data->interval)) || 109 !data->valid) { 110 int i; 111 112 dev_dbg(dev, "Updating lm95241 data.\n"); 113 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++) 114 data->temp[i] 115 = i2c_smbus_read_byte_data(client, 116 lm95241_reg_address[i]); 117 118 data->status = i2c_smbus_read_byte_data(client, 119 LM95241_REG_R_STATUS); 120 data->last_updated = jiffies; 121 data->valid = true; 122 } 123 124 mutex_unlock(&data->update_lock); 125 126 return data; 127 } 128 129 static int lm95241_read_chip(struct device *dev, u32 attr, int channel, 130 long *val) 131 { 132 struct lm95241_data *data = dev_get_drvdata(dev); 133 134 switch (attr) { 135 case hwmon_chip_update_interval: 136 *val = data->interval; 137 return 0; 138 default: 139 return -EOPNOTSUPP; 140 } 141 } 142 143 static int lm95241_read_temp(struct device *dev, u32 attr, int channel, 144 long *val) 145 { 146 struct lm95241_data *data = lm95241_update_device(dev); 147 148 switch (attr) { 149 case hwmon_temp_input: 150 if (!channel || (data->config & BIT(channel - 1))) 151 *val = temp_from_reg_signed(data->temp[channel * 2], 152 data->temp[channel * 2 + 1]); 153 else 154 *val = temp_from_reg_unsigned(data->temp[channel * 2], 155 data->temp[channel * 2 + 1]); 156 return 0; 157 case hwmon_temp_min: 158 if (channel == 1) 159 *val = (data->config & R1DF_MASK) ? -128000 : 0; 160 else 161 *val = (data->config & R2DF_MASK) ? -128000 : 0; 162 return 0; 163 case hwmon_temp_max: 164 if (channel == 1) 165 *val = (data->config & R1DF_MASK) ? 127875 : 255875; 166 else 167 *val = (data->config & R2DF_MASK) ? 127875 : 255875; 168 return 0; 169 case hwmon_temp_type: 170 if (channel == 1) 171 *val = (data->model & R1MS_MASK) ? 1 : 2; 172 else 173 *val = (data->model & R2MS_MASK) ? 1 : 2; 174 return 0; 175 case hwmon_temp_fault: 176 if (channel == 1) 177 *val = !!(data->status & R1DM); 178 else 179 *val = !!(data->status & R2DM); 180 return 0; 181 default: 182 return -EOPNOTSUPP; 183 } 184 } 185 186 static int lm95241_read(struct device *dev, enum hwmon_sensor_types type, 187 u32 attr, int channel, long *val) 188 { 189 switch (type) { 190 case hwmon_chip: 191 return lm95241_read_chip(dev, attr, channel, val); 192 case hwmon_temp: 193 return lm95241_read_temp(dev, attr, channel, val); 194 default: 195 return -EOPNOTSUPP; 196 } 197 } 198 199 static int lm95241_write_chip(struct device *dev, u32 attr, int channel, 200 long val) 201 { 202 struct lm95241_data *data = dev_get_drvdata(dev); 203 int convrate; 204 u8 config; 205 int ret; 206 207 mutex_lock(&data->update_lock); 208 209 switch (attr) { 210 case hwmon_chip_update_interval: 211 config = data->config & ~CFG_CRMASK; 212 if (val < 130) { 213 convrate = 76; 214 config |= CFG_CR0076; 215 } else if (val < 590) { 216 convrate = 182; 217 config |= CFG_CR0182; 218 } else if (val < 1850) { 219 convrate = 1000; 220 config |= CFG_CR1000; 221 } else { 222 convrate = 2700; 223 config |= CFG_CR2700; 224 } 225 data->interval = convrate; 226 data->config = config; 227 ret = i2c_smbus_write_byte_data(data->client, 228 LM95241_REG_RW_CONFIG, config); 229 break; 230 default: 231 ret = -EOPNOTSUPP; 232 break; 233 } 234 mutex_unlock(&data->update_lock); 235 return ret; 236 } 237 238 static int lm95241_write_temp(struct device *dev, u32 attr, int channel, 239 long val) 240 { 241 struct lm95241_data *data = dev_get_drvdata(dev); 242 struct i2c_client *client = data->client; 243 int ret; 244 245 mutex_lock(&data->update_lock); 246 247 switch (attr) { 248 case hwmon_temp_min: 249 if (channel == 1) { 250 if (val < 0) 251 data->config |= R1DF_MASK; 252 else 253 data->config &= ~R1DF_MASK; 254 } else { 255 if (val < 0) 256 data->config |= R2DF_MASK; 257 else 258 data->config &= ~R2DF_MASK; 259 } 260 data->valid = false; 261 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, 262 data->config); 263 break; 264 case hwmon_temp_max: 265 if (channel == 1) { 266 if (val <= 127875) 267 data->config |= R1DF_MASK; 268 else 269 data->config &= ~R1DF_MASK; 270 } else { 271 if (val <= 127875) 272 data->config |= R2DF_MASK; 273 else 274 data->config &= ~R2DF_MASK; 275 } 276 data->valid = false; 277 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, 278 data->config); 279 break; 280 case hwmon_temp_type: 281 if (val != 1 && val != 2) { 282 ret = -EINVAL; 283 break; 284 } 285 if (channel == 1) { 286 data->trutherm &= ~(TT_MASK << TT1_SHIFT); 287 if (val == 1) { 288 data->model |= R1MS_MASK; 289 data->trutherm |= (TT_ON << TT1_SHIFT); 290 } else { 291 data->model &= ~R1MS_MASK; 292 data->trutherm |= (TT_OFF << TT1_SHIFT); 293 } 294 } else { 295 data->trutherm &= ~(TT_MASK << TT2_SHIFT); 296 if (val == 1) { 297 data->model |= R2MS_MASK; 298 data->trutherm |= (TT_ON << TT2_SHIFT); 299 } else { 300 data->model &= ~R2MS_MASK; 301 data->trutherm |= (TT_OFF << TT2_SHIFT); 302 } 303 } 304 ret = i2c_smbus_write_byte_data(client, 305 LM95241_REG_RW_REMOTE_MODEL, 306 data->model); 307 if (ret < 0) 308 break; 309 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, 310 data->trutherm); 311 break; 312 default: 313 ret = -EOPNOTSUPP; 314 break; 315 } 316 317 mutex_unlock(&data->update_lock); 318 319 return ret; 320 } 321 322 static int lm95241_write(struct device *dev, enum hwmon_sensor_types type, 323 u32 attr, int channel, long val) 324 { 325 switch (type) { 326 case hwmon_chip: 327 return lm95241_write_chip(dev, attr, channel, val); 328 case hwmon_temp: 329 return lm95241_write_temp(dev, attr, channel, val); 330 default: 331 return -EOPNOTSUPP; 332 } 333 } 334 335 static umode_t lm95241_is_visible(const void *data, 336 enum hwmon_sensor_types type, 337 u32 attr, int channel) 338 { 339 switch (type) { 340 case hwmon_chip: 341 switch (attr) { 342 case hwmon_chip_update_interval: 343 return 0644; 344 } 345 break; 346 case hwmon_temp: 347 switch (attr) { 348 case hwmon_temp_input: 349 return 0444; 350 case hwmon_temp_fault: 351 return 0444; 352 case hwmon_temp_min: 353 case hwmon_temp_max: 354 case hwmon_temp_type: 355 return 0644; 356 } 357 break; 358 default: 359 break; 360 } 361 return 0; 362 } 363 364 /* Return 0 if detection is successful, -ENODEV otherwise */ 365 static int lm95241_detect(struct i2c_client *new_client, 366 struct i2c_board_info *info) 367 { 368 struct i2c_adapter *adapter = new_client->adapter; 369 const char *name; 370 int mfg_id, chip_id; 371 372 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 373 return -ENODEV; 374 375 mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID); 376 if (mfg_id != NATSEMI_MAN_ID) 377 return -ENODEV; 378 379 chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID); 380 switch (chip_id) { 381 case LM95231_CHIP_ID: 382 name = "lm95231"; 383 break; 384 case LM95241_CHIP_ID: 385 name = "lm95241"; 386 break; 387 default: 388 return -ENODEV; 389 } 390 391 /* Fill the i2c board info */ 392 strscpy(info->type, name, I2C_NAME_SIZE); 393 return 0; 394 } 395 396 static void lm95241_init_client(struct i2c_client *client, 397 struct lm95241_data *data) 398 { 399 data->interval = 1000; 400 data->config = CFG_CR1000; 401 data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT); 402 403 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config); 404 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER, 405 R1FE_MASK | R2FE_MASK); 406 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, 407 data->trutherm); 408 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, 409 data->model); 410 } 411 412 static const struct hwmon_channel_info * const lm95241_info[] = { 413 HWMON_CHANNEL_INFO(chip, 414 HWMON_C_UPDATE_INTERVAL), 415 HWMON_CHANNEL_INFO(temp, 416 HWMON_T_INPUT, 417 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | 418 HWMON_T_TYPE | HWMON_T_FAULT, 419 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | 420 HWMON_T_TYPE | HWMON_T_FAULT), 421 NULL 422 }; 423 424 static const struct hwmon_ops lm95241_hwmon_ops = { 425 .is_visible = lm95241_is_visible, 426 .read = lm95241_read, 427 .write = lm95241_write, 428 }; 429 430 static const struct hwmon_chip_info lm95241_chip_info = { 431 .ops = &lm95241_hwmon_ops, 432 .info = lm95241_info, 433 }; 434 435 static int lm95241_probe(struct i2c_client *client) 436 { 437 struct device *dev = &client->dev; 438 struct lm95241_data *data; 439 struct device *hwmon_dev; 440 441 data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL); 442 if (!data) 443 return -ENOMEM; 444 445 data->client = client; 446 mutex_init(&data->update_lock); 447 448 /* Initialize the LM95241 chip */ 449 lm95241_init_client(client, data); 450 451 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 452 data, 453 &lm95241_chip_info, 454 NULL); 455 return PTR_ERR_OR_ZERO(hwmon_dev); 456 } 457 458 /* Driver data (common to all clients) */ 459 static const struct i2c_device_id lm95241_id[] = { 460 { "lm95231", 0 }, 461 { "lm95241", 0 }, 462 { } 463 }; 464 MODULE_DEVICE_TABLE(i2c, lm95241_id); 465 466 static struct i2c_driver lm95241_driver = { 467 .class = I2C_CLASS_HWMON, 468 .driver = { 469 .name = DEVNAME, 470 }, 471 .probe_new = lm95241_probe, 472 .id_table = lm95241_id, 473 .detect = lm95241_detect, 474 .address_list = normal_i2c, 475 }; 476 477 module_i2c_driver(lm95241_driver); 478 479 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>"); 480 MODULE_DESCRIPTION("LM95231/LM95241 sensor driver"); 481 MODULE_LICENSE("GPL"); 482