drivers/hwmon/pmbus/ltc2978.c

   1 /*
   2  * Hardware monitoring driver for LTC2974, LTC2977, LTC2978, LTC3880,
   3  * and LTC3883
   4  *
   5  * Copyright (c) 2011 Ericsson AB.
   6  * Copyright (c) 2013 Guenter Roeck
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/err.h>
  27 #include <linux/slab.h>
  28 #include <linux/i2c.h>
  29 #include "pmbus.h"
  30
  31 enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883 };
  32
  33 /* Common for all chips */
  34 #define LTC2978_MFR_VOUT_PEAK           0xdd
  35 #define LTC2978_MFR_VIN_PEAK            0xde
  36 #define LTC2978_MFR_TEMPERATURE_PEAK    0xdf
  37 #define LTC2978_MFR_SPECIAL_ID          0xe7
  38
  39 /* LTC2974, LCT2977, and LTC2978 */
  40 #define LTC2978_MFR_VOUT_MIN            0xfb
  41 #define LTC2978_MFR_VIN_MIN             0xfc
  42 #define LTC2978_MFR_TEMPERATURE_MIN     0xfd
  43
  44 /* LTC2974 only */
  45 #define LTC2974_MFR_IOUT_PEAK           0xd7
  46 #define LTC2974_MFR_IOUT_MIN            0xd8
  47
  48 /* LTC3880 and LTC3883 */
  49 #define LTC3880_MFR_IOUT_PEAK           0xd7
  50 #define LTC3880_MFR_CLEAR_PEAKS         0xe3
  51 #define LTC3880_MFR_TEMPERATURE2_PEAK   0xf4
  52
  53 /* LTC3883 only */
  54 #define LTC3883_MFR_IIN_PEAK            0xe1
  55
  56 #define LTC2974_ID                      0x0212
  57 #define LTC2977_ID                      0x0130
  58 #define LTC2978_ID_REV1                 0x0121
  59 #define LTC2978_ID_REV2                 0x0122
  60 #define LTC2978A_ID                     0x0124
  61 #define LTC3880_ID                      0x4000
  62 #define LTC3880_ID_MASK                 0xff00
  63 #define LTC3883_ID                      0x4300
  64 #define LTC3883_ID_MASK                 0xff00
  65
  66 #define LTC2974_NUM_PAGES               4
  67 #define LTC2978_NUM_PAGES               8
  68 #define LTC3880_NUM_PAGES               2
  69 #define LTC3883_NUM_PAGES               1
  70
  71 /*
  72  * LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which
  73  * happens pretty much each time chip data is updated. Raw peak data therefore
  74  * does not provide much value. To be able to provide useful peak data, keep an
  75  * internal cache of measured peak data, which is only cleared if an explicit
  76  * "clear peak" command is executed for the sensor in question.
  77  */
  78
  79 struct ltc2978_data {
  80         enum chips id;
  81         u16 vin_min, vin_max;
  82         u16 temp_min[LTC2974_NUM_PAGES], temp_max[LTC2974_NUM_PAGES];
  83         u16 vout_min[LTC2978_NUM_PAGES], vout_max[LTC2978_NUM_PAGES];
  84         u16 iout_min[LTC2974_NUM_PAGES], iout_max[LTC2974_NUM_PAGES];
  85         u16 iin_max;
  86         u16 temp2_max;
  87         struct pmbus_driver_info info;
  88 };
  89
  90 #define to_ltc2978_data(x)  container_of(x, struct ltc2978_data, info)
  91
  92 static inline int lin11_to_val(int data)
  93 {
  94         s16 e = ((s16)data) >> 11;
  95         s32 m = (((s16)(data << 5)) >> 5);
  96
  97         /*
  98          * mantissa is 10 bit + sign, exponent adds up to 15 bit.
  99          * Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31).
 100          */
 101         e += 6;
 102         return (e < 0 ? m >> -e : m << e);
 103 }
 104
 105 static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
 106                                          int reg)
 107 {
 108         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 109         struct ltc2978_data *data = to_ltc2978_data(info);
 110         int ret;
 111
 112         switch (reg) {
 113         case PMBUS_VIRT_READ_VIN_MAX:
 114                 ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_PEAK);
 115                 if (ret >= 0) {
 116                         if (lin11_to_val(ret) > lin11_to_val(data->vin_max))
 117                                 data->vin_max = ret;
 118                         ret = data->vin_max;
 119                 }
 120                 break;
 121         case PMBUS_VIRT_READ_VOUT_MAX:
 122                 ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_PEAK);
 123                 if (ret >= 0) {
 124                         /*
 125                          * VOUT is 16 bit unsigned with fixed exponent,
 126                          * so we can compare it directly
 127                          */
 128                         if (ret > data->vout_max[page])
 129                                 data->vout_max[page] = ret;
 130                         ret = data->vout_max[page];
 131                 }
 132                 break;
 133         case PMBUS_VIRT_READ_TEMP_MAX:
 134                 ret = pmbus_read_word_data(client, page,
 135                                            LTC2978_MFR_TEMPERATURE_PEAK);
 136                 if (ret >= 0) {
 137                         if (lin11_to_val(ret)
 138                             > lin11_to_val(data->temp_max[page]))
 139                                 data->temp_max[page] = ret;
 140                         ret = data->temp_max[page];
 141                 }
 142                 break;
 143         case PMBUS_VIRT_RESET_VOUT_HISTORY:
 144         case PMBUS_VIRT_RESET_VIN_HISTORY:
 145         case PMBUS_VIRT_RESET_TEMP_HISTORY:
 146                 ret = 0;
 147                 break;
 148         default:
 149                 ret = -ENODATA;
 150                 break;
 151         }
 152         return ret;
 153 }
 154
 155 static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
 156 {
 157         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 158         struct ltc2978_data *data = to_ltc2978_data(info);
 159         int ret;
 160
 161         switch (reg) {
 162         case PMBUS_VIRT_READ_VIN_MIN:
 163                 ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_MIN);
 164                 if (ret >= 0) {
 165                         if (lin11_to_val(ret) < lin11_to_val(data->vin_min))
 166                                 data->vin_min = ret;
 167                         ret = data->vin_min;
 168                 }
 169                 break;
 170         case PMBUS_VIRT_READ_VOUT_MIN:
 171                 ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_MIN);
 172                 if (ret >= 0) {
 173                         /*
 174                          * VOUT_MIN is known to not be supported on some lots
 175                          * of LTC2978 revision 1, and will return the maximum
 176                          * possible voltage if read. If VOUT_MAX is valid and
 177                          * lower than the reading of VOUT_MIN, use it instead.
 178                          */
 179                         if (data->vout_max[page] && ret > data->vout_max[page])
 180                                 ret = data->vout_max[page];
 181                         if (ret < data->vout_min[page])
 182                                 data->vout_min[page] = ret;
 183                         ret = data->vout_min[page];
 184                 }
 185                 break;
 186         case PMBUS_VIRT_READ_TEMP_MIN:
 187                 ret = pmbus_read_word_data(client, page,
 188                                            LTC2978_MFR_TEMPERATURE_MIN);
 189                 if (ret >= 0) {
 190                         if (lin11_to_val(ret)
 191                             < lin11_to_val(data->temp_min[page]))
 192                                 data->temp_min[page] = ret;
 193                         ret = data->temp_min[page];
 194                 }
 195                 break;
 196         case PMBUS_VIRT_READ_IOUT_MAX:
 197         case PMBUS_VIRT_RESET_IOUT_HISTORY:
 198         case PMBUS_VIRT_READ_TEMP2_MAX:
 199         case PMBUS_VIRT_RESET_TEMP2_HISTORY:
 200                 ret = -ENXIO;
 201                 break;
 202         default:
 203                 ret = ltc2978_read_word_data_common(client, page, reg);
 204                 break;
 205         }
 206         return ret;
 207 }
 208
 209 static int ltc2974_read_word_data(struct i2c_client *client, int page, int reg)
 210 {
 211         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 212         struct ltc2978_data *data = to_ltc2978_data(info);
 213         int ret;
 214
 215         switch (reg) {
 216         case PMBUS_VIRT_READ_IOUT_MAX:
 217                 ret = pmbus_read_word_data(client, page, LTC2974_MFR_IOUT_PEAK);
 218                 if (ret >= 0) {
 219                         if (lin11_to_val(ret)
 220                             > lin11_to_val(data->iout_max[page]))
 221                                 data->iout_max[page] = ret;
 222                         ret = data->iout_max[page];
 223                 }
 224                 break;
 225         case PMBUS_VIRT_READ_IOUT_MIN:
 226                 ret = pmbus_read_word_data(client, page, LTC2974_MFR_IOUT_MIN);
 227                 if (ret >= 0) {
 228                         if (lin11_to_val(ret)
 229                             < lin11_to_val(data->iout_min[page]))
 230                                 data->iout_min[page] = ret;
 231                         ret = data->iout_min[page];
 232                 }
 233                 break;
 234         case PMBUS_VIRT_RESET_IOUT_HISTORY:
 235                 ret = 0;
 236                 break;
 237         default:
 238                 ret = ltc2978_read_word_data(client, page, reg);
 239                 break;
 240         }
 241         return ret;
 242 }
 243
 244 static int ltc3880_read_word_data(struct i2c_client *client, int page, int reg)
 245 {
 246         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 247         struct ltc2978_data *data = to_ltc2978_data(info);
 248         int ret;
 249
 250         switch (reg) {
 251         case PMBUS_VIRT_READ_IOUT_MAX:
 252                 ret = pmbus_read_word_data(client, page, LTC3880_MFR_IOUT_PEAK);
 253                 if (ret >= 0) {
 254                         if (lin11_to_val(ret)
 255                             > lin11_to_val(data->iout_max[page]))
 256                                 data->iout_max[page] = ret;
 257                         ret = data->iout_max[page];
 258                 }
 259                 break;
 260         case PMBUS_VIRT_READ_TEMP2_MAX:
 261                 ret = pmbus_read_word_data(client, page,
 262                                            LTC3880_MFR_TEMPERATURE2_PEAK);
 263                 if (ret >= 0) {
 264                         if (lin11_to_val(ret) > lin11_to_val(data->temp2_max))
 265                                 data->temp2_max = ret;
 266                         ret = data->temp2_max;
 267                 }
 268                 break;
 269         case PMBUS_VIRT_READ_VIN_MIN:
 270         case PMBUS_VIRT_READ_VOUT_MIN:
 271         case PMBUS_VIRT_READ_TEMP_MIN:
 272                 ret = -ENXIO;
 273                 break;
 274         case PMBUS_VIRT_RESET_IOUT_HISTORY:
 275         case PMBUS_VIRT_RESET_TEMP2_HISTORY:
 276                 ret = 0;
 277                 break;
 278         default:
 279                 ret = ltc2978_read_word_data_common(client, page, reg);
 280                 break;
 281         }
 282         return ret;
 283 }
 284
 285 static int ltc3883_read_word_data(struct i2c_client *client, int page, int reg)
 286 {
 287         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 288         struct ltc2978_data *data = to_ltc2978_data(info);
 289         int ret;
 290
 291         switch (reg) {
 292         case PMBUS_VIRT_READ_IIN_MAX:
 293                 ret = pmbus_read_word_data(client, page, LTC3883_MFR_IIN_PEAK);
 294                 if (ret >= 0) {
 295                         if (lin11_to_val(ret)
 296                             > lin11_to_val(data->iin_max))
 297                                 data->iin_max = ret;
 298                         ret = data->iin_max;
 299                 }
 300                 break;
 301         case PMBUS_VIRT_RESET_IIN_HISTORY:
 302                 ret = 0;
 303                 break;
 304         default:
 305                 ret = ltc3880_read_word_data(client, page, reg);
 306                 break;
 307         }
 308         return ret;
 309 }
 310
 311 static int ltc2978_clear_peaks(struct i2c_client *client, int page,
 312                                enum chips id)
 313 {
 314         int ret;
 315
 316         if (id == ltc3880 || id == ltc3883)
 317                 ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
 318         else
 319                 ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
 320
 321         return ret;
 322 }
 323
 324 static int ltc2978_write_word_data(struct i2c_client *client, int page,
 325                                     int reg, u16 word)
 326 {
 327         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 328         struct ltc2978_data *data = to_ltc2978_data(info);
 329         int ret;
 330
 331         switch (reg) {
 332         case PMBUS_VIRT_RESET_IIN_HISTORY:
 333                 data->iin_max = 0x7c00;
 334                 ret = ltc2978_clear_peaks(client, page, data->id);
 335                 break;
 336         case PMBUS_VIRT_RESET_IOUT_HISTORY:
 337                 data->iout_max[page] = 0x7c00;
 338                 data->iout_min[page] = 0xfbff;
 339                 ret = ltc2978_clear_peaks(client, page, data->id);
 340                 break;
 341         case PMBUS_VIRT_RESET_TEMP2_HISTORY:
 342                 data->temp2_max = 0x7c00;
 343                 ret = ltc2978_clear_peaks(client, page, data->id);
 344                 break;
 345         case PMBUS_VIRT_RESET_VOUT_HISTORY:
 346                 data->vout_min[page] = 0xffff;
 347                 data->vout_max[page] = 0;
 348                 ret = ltc2978_clear_peaks(client, page, data->id);
 349                 break;
 350         case PMBUS_VIRT_RESET_VIN_HISTORY:
 351                 data->vin_min = 0x7bff;
 352                 data->vin_max = 0x7c00;
 353                 ret = ltc2978_clear_peaks(client, page, data->id);
 354                 break;
 355         case PMBUS_VIRT_RESET_TEMP_HISTORY:
 356                 data->temp_min[page] = 0x7bff;
 357                 data->temp_max[page] = 0x7c00;
 358                 ret = ltc2978_clear_peaks(client, page, data->id);
 359                 break;
 360         default:
 361                 ret = -ENODATA;
 362                 break;
 363         }
 364         return ret;
 365 }
 366
 367 static const struct i2c_device_id ltc2978_id[] = {
 368         {"ltc2974", ltc2974},
 369         {"ltc2977", ltc2977},
 370         {"ltc2978", ltc2978},
 371         {"ltc3880", ltc3880},
 372         {"ltc3883", ltc3883},
 373         {}
 374 };
 375 MODULE_DEVICE_TABLE(i2c, ltc2978_id);
 376
 377 static int ltc2978_probe(struct i2c_client *client,
 378                          const struct i2c_device_id *id)
 379 {
 380         int chip_id, i;
 381         struct ltc2978_data *data;
 382         struct pmbus_driver_info *info;
 383
 384         if (!i2c_check_functionality(client->adapter,
 385                                      I2C_FUNC_SMBUS_READ_WORD_DATA))
 386                 return -ENODEV;
 387
 388         data = devm_kzalloc(&client->dev, sizeof(struct ltc2978_data),
 389                             GFP_KERNEL);
 390         if (!data)
 391                 return -ENOMEM;
 392
 393         chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
 394         if (chip_id < 0)
 395                 return chip_id;
 396
 397         if (chip_id == LTC2974_ID) {
 398                 data->id = ltc2974;
 399         } else if (chip_id == LTC2977_ID) {
 400                 data->id = ltc2977;
 401         } else if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2 ||
 402                    chip_id == LTC2978A_ID) {
 403                 data->id = ltc2978;
 404         } else if ((chip_id & LTC3880_ID_MASK) == LTC3880_ID) {
 405                 data->id = ltc3880;
 406         } else if ((chip_id & LTC3883_ID_MASK) == LTC3883_ID) {
 407                 data->id = ltc3883;
 408         } else {
 409                 dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
 410                 return -ENODEV;
 411         }
 412         if (data->id != id->driver_data)
 413                 dev_warn(&client->dev,
 414                          "Device mismatch: Configured %s, detected %s\n",
 415                          id->name,
 416                          ltc2978_id[data->id].name);
 417
 418         info = &data->info;
 419         info->write_word_data = ltc2978_write_word_data;
 420
 421         data->vin_min = 0x7bff;
 422         data->vin_max = 0x7c00;
 423         for (i = 0; i < ARRAY_SIZE(data->vout_min); i++)
 424                 data->vout_min[i] = 0xffff;
 425         for (i = 0; i < ARRAY_SIZE(data->iout_min); i++)
 426                 data->iout_min[i] = 0xfbff;
 427         for (i = 0; i < ARRAY_SIZE(data->iout_max); i++)
 428                 data->iout_max[i] = 0x7c00;
 429         for (i = 0; i < ARRAY_SIZE(data->temp_min); i++)
 430                 data->temp_min[i] = 0x7bff;
 431         for (i = 0; i < ARRAY_SIZE(data->temp_max); i++)
 432                 data->temp_max[i] = 0x7c00;
 433         data->temp2_max = 0x7c00;
 434
 435         switch (data->id) {
 436         case ltc2974:
 437                 info->read_word_data = ltc2974_read_word_data;
 438                 info->pages = LTC2974_NUM_PAGES;
 439                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 440                   | PMBUS_HAVE_TEMP2;
 441                 for (i = 0; i < info->pages; i++) {
 442                         info->func[i] |= PMBUS_HAVE_VOUT
 443                           | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
 444                           | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
 445                           | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
 446                 }
 447                 break;
 448         case ltc2977:
 449         case ltc2978:
 450                 info->read_word_data = ltc2978_read_word_data;
 451                 info->pages = LTC2978_NUM_PAGES;
 452                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 453                   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 454                   | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 455                 for (i = 1; i < LTC2978_NUM_PAGES; i++) {
 456                         info->func[i] = PMBUS_HAVE_VOUT
 457                           | PMBUS_HAVE_STATUS_VOUT;
 458                 }
 459                 break;
 460         case ltc3880:
 461                 info->read_word_data = ltc3880_read_word_data;
 462                 info->pages = LTC3880_NUM_PAGES;
 463                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
 464                   | PMBUS_HAVE_STATUS_INPUT
 465                   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 466                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 467                   | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
 468                   | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 469                 info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 470                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 471                   | PMBUS_HAVE_POUT
 472                   | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 473                 break;
 474         case ltc3883:
 475                 info->read_word_data = ltc3883_read_word_data;
 476                 info->pages = LTC3883_NUM_PAGES;
 477                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
 478                   | PMBUS_HAVE_STATUS_INPUT
 479                   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 480                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 481                   | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
 482                   | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 483                 break;
 484         default:
 485                 return -ENODEV;
 486         }
 487         return pmbus_do_probe(client, id, info);
 488 }
 489
 490 /* This is the driver that will be inserted */
 491 static struct i2c_driver ltc2978_driver = {
 492         .driver = {
 493                    .name = "ltc2978",
 494                    },
 495         .probe = ltc2978_probe,
 496         .remove = pmbus_do_remove,
 497         .id_table = ltc2978_id,
 498 };
 499
 500 module_i2c_driver(ltc2978_driver);
 501
 502 MODULE_AUTHOR("Guenter Roeck");
 503 MODULE_DESCRIPTION("PMBus driver for LTC2974, LTC2978, LTC3880, and LTC3883");
 504 MODULE_LICENSE("GPL");