drivers/hwmon/lm95241.c

   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          = 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");