linux/drivers/hwmon/lm95241.c
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   1/*
   2 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
   3 *
   4 * The LM95241 is a sensor chip made by National Semiconductors.
   5 * It reports up to three temperatures (its own plus up to two external ones).
   6 * Complete datasheet can be obtained from National's website at:
   7 *   http://www.national.com/ds.cgi/LM/LM95241.pdf
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 */
  19
  20#include <linux/bitops.h>
  21#include <linux/err.h>
  22#include <linux/i2c.h>
  23#include <linux/init.h>
  24#include <linux/jiffies.h>
  25#include <linux/hwmon.h>
  26#include <linux/module.h>
  27#include <linux/mutex.h>
  28#include <linux/slab.h>
  29
  30#define DEVNAME "lm95241"
  31
  32static const unsigned short normal_i2c[] = {
  33        0x19, 0x2a, 0x2b, I2C_CLIENT_END };
  34
  35/* LM95241 registers */
  36#define LM95241_REG_R_MAN_ID            0xFE
  37#define LM95241_REG_R_CHIP_ID           0xFF
  38#define LM95241_REG_R_STATUS            0x02
  39#define LM95241_REG_RW_CONFIG           0x03
  40#define LM95241_REG_RW_REM_FILTER       0x06
  41#define LM95241_REG_RW_TRUTHERM         0x07
  42#define LM95241_REG_W_ONE_SHOT          0x0F
  43#define LM95241_REG_R_LOCAL_TEMPH       0x10
  44#define LM95241_REG_R_REMOTE1_TEMPH     0x11
  45#define LM95241_REG_R_REMOTE2_TEMPH     0x12
  46#define LM95241_REG_R_LOCAL_TEMPL       0x20
  47#define LM95241_REG_R_REMOTE1_TEMPL     0x21
  48#define LM95241_REG_R_REMOTE2_TEMPL     0x22
  49#define LM95241_REG_RW_REMOTE_MODEL     0x30
  50
  51/* LM95241 specific bitfields */
  52#define CFG_STOP        BIT(6)
  53#define CFG_CR0076      0x00
  54#define CFG_CR0182      BIT(4)
  55#define CFG_CR1000      BIT(5)
  56#define CFG_CR2700      (BIT(4) | BIT(5))
  57#define CFG_CRMASK      (BIT(4) | BIT(5))
  58#define R1MS_MASK       BIT(0)
  59#define R2MS_MASK       BIT(2)
  60#define R1DF_MASK       BIT(1)
  61#define R2DF_MASK       BIT(2)
  62#define R1FE_MASK       BIT(0)
  63#define R2FE_MASK       BIT(2)
  64#define R1DM            BIT(0)
  65#define R2DM            BIT(1)
  66#define TT1_SHIFT       0
  67#define TT2_SHIFT       4
  68#define TT_OFF          0
  69#define TT_ON           1
  70#define TT_MASK         7
  71#define NATSEMI_MAN_ID  0x01
  72#define LM95231_CHIP_ID 0xA1
  73#define LM95241_CHIP_ID 0xA4
  74
  75static const u8 lm95241_reg_address[] = {
  76        LM95241_REG_R_LOCAL_TEMPH,
  77        LM95241_REG_R_LOCAL_TEMPL,
  78        LM95241_REG_R_REMOTE1_TEMPH,
  79        LM95241_REG_R_REMOTE1_TEMPL,
  80        LM95241_REG_R_REMOTE2_TEMPH,
  81        LM95241_REG_R_REMOTE2_TEMPL
  82};
  83
  84/* Client data (each client gets its own) */
  85struct lm95241_data {
  86        struct i2c_client *client;
  87        struct mutex update_lock;
  88        unsigned long last_updated;     /* in jiffies */
  89        unsigned long interval;         /* in milli-seconds */
  90        char valid;             /* zero until following fields are valid */
  91        /* registers values */
  92        u8 temp[ARRAY_SIZE(lm95241_reg_address)];
  93        u8 status, config, model, trutherm;
  94};
  95
  96/* Conversions */
  97static int temp_from_reg_signed(u8 val_h, u8 val_l)
  98{
  99        s16 val_hl = (val_h << 8) | val_l;
 100        return val_hl * 1000 / 256;
 101}
 102
 103static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 104{
 105        u16 val_hl = (val_h << 8) | val_l;
 106        return val_hl * 1000 / 256;
 107}
 108
 109static struct lm95241_data *lm95241_update_device(struct device *dev)
 110{
 111        struct lm95241_data *data = dev_get_drvdata(dev);
 112        struct i2c_client *client = data->client;
 113
 114        mutex_lock(&data->update_lock);
 115
 116        if (time_after(jiffies, data->last_updated
 117                       + msecs_to_jiffies(data->interval)) ||
 118            !data->valid) {
 119                int i;
 120
 121                dev_dbg(dev, "Updating lm95241 data.\n");
 122                for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
 123                        data->temp[i]
 124                          = i2c_smbus_read_byte_data(client,
 125                                                     lm95241_reg_address[i]);
 126
 127                data->status = i2c_smbus_read_byte_data(client,
 128                                                        LM95241_REG_R_STATUS);
 129                data->last_updated = jiffies;
 130                data->valid = 1;
 131        }
 132
 133        mutex_unlock(&data->update_lock);
 134
 135        return data;
 136}
 137
 138static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
 139                             long *val)
 140{
 141        struct lm95241_data *data = dev_get_drvdata(dev);
 142
 143        switch (attr) {
 144        case hwmon_chip_update_interval:
 145                *val = data->interval;
 146                return 0;
 147        default:
 148                return -EOPNOTSUPP;
 149        }
 150}
 151
 152static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
 153                             long *val)
 154{
 155        struct lm95241_data *data = lm95241_update_device(dev);
 156
 157        switch (attr) {
 158        case hwmon_temp_input:
 159                if (!channel || (data->config & BIT(channel - 1)))
 160                        *val = temp_from_reg_signed(data->temp[channel * 2],
 161                                                data->temp[channel * 2 + 1]);
 162                else
 163                        *val = temp_from_reg_unsigned(data->temp[channel * 2],
 164                                                data->temp[channel * 2 + 1]);
 165                return 0;
 166        case hwmon_temp_min:
 167                if (channel == 1)
 168                        *val = (data->config & R1DF_MASK) ? -128000 : 0;
 169                else
 170                        *val = (data->config & R2DF_MASK) ? -128000 : 0;
 171                return 0;
 172        case hwmon_temp_max:
 173                if (channel == 1)
 174                        *val = (data->config & R1DF_MASK) ? 127875 : 255875;
 175                else
 176                        *val = (data->config & R2DF_MASK) ? 127875 : 255875;
 177                return 0;
 178        case hwmon_temp_type:
 179                if (channel == 1)
 180                        *val = (data->model & R1MS_MASK) ? 1 : 2;
 181                else
 182                        *val = (data->model & R2MS_MASK) ? 1 : 2;
 183                return 0;
 184        case hwmon_temp_fault:
 185                if (channel == 1)
 186                        *val = !!(data->status & R1DM);
 187                else
 188                        *val = !!(data->status & R2DM);
 189                return 0;
 190        default:
 191                return -EOPNOTSUPP;
 192        }
 193}
 194
 195static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
 196                        u32 attr, int channel, long *val)
 197{
 198        switch (type) {
 199        case hwmon_chip:
 200                return lm95241_read_chip(dev, attr, channel, val);
 201        case hwmon_temp:
 202                return lm95241_read_temp(dev, attr, channel, val);
 203        default:
 204                return -EOPNOTSUPP;
 205        }
 206}
 207
 208static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
 209                              long val)
 210{
 211        struct lm95241_data *data = dev_get_drvdata(dev);
 212        int convrate;
 213        u8 config;
 214        int ret;
 215
 216        mutex_lock(&data->update_lock);
 217
 218        switch (attr) {
 219        case hwmon_chip_update_interval:
 220                config = data->config & ~CFG_CRMASK;
 221                if (val < 130) {
 222                        convrate = 76;
 223                        config |= CFG_CR0076;
 224                } else if (val < 590) {
 225                        convrate = 182;
 226                        config |= CFG_CR0182;
 227                } else if (val < 1850) {
 228                        convrate = 1000;
 229                        config |= CFG_CR1000;
 230                } else {
 231                        convrate = 2700;
 232                        config |= CFG_CR2700;
 233                }
 234                data->interval = convrate;
 235                data->config = config;
 236                ret = i2c_smbus_write_byte_data(data->client,
 237                                                LM95241_REG_RW_CONFIG, config);
 238                break;
 239        default:
 240                ret = -EOPNOTSUPP;
 241                break;
 242        }
 243        mutex_unlock(&data->update_lock);
 244        return ret;
 245}
 246
 247static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
 248                              long val)
 249{
 250        struct lm95241_data *data = dev_get_drvdata(dev);
 251        struct i2c_client *client = data->client;
 252        int ret;
 253
 254        mutex_lock(&data->update_lock);
 255
 256        switch (attr) {
 257        case hwmon_temp_min:
 258                if (channel == 1) {
 259                        if (val < 0)
 260                                data->config |= R1DF_MASK;
 261                        else
 262                                data->config &= ~R1DF_MASK;
 263                } else {
 264                        if (val < 0)
 265                                data->config |= R2DF_MASK;
 266                        else
 267                                data->config &= ~R2DF_MASK;
 268                }
 269                data->valid = 0;
 270                ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 271                                                data->config);
 272                break;
 273        case hwmon_temp_max:
 274                if (channel == 1) {
 275                        if (val <= 127875)
 276                                data->config |= R1DF_MASK;
 277                        else
 278                                data->config &= ~R1DF_MASK;
 279                } else {
 280                        if (val <= 127875)
 281                                data->config |= R2DF_MASK;
 282                        else
 283                                data->config &= ~R2DF_MASK;
 284                }
 285                data->valid = 0;
 286                ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 287                                                data->config);
 288                break;
 289        case hwmon_temp_type:
 290                if (val != 1 && val != 2) {
 291                        ret = -EINVAL;
 292                        break;
 293                }
 294                if (channel == 1) {
 295                        data->trutherm &= ~(TT_MASK << TT1_SHIFT);
 296                        if (val == 1) {
 297                                data->model |= R1MS_MASK;
 298                                data->trutherm |= (TT_ON << TT1_SHIFT);
 299                        } else {
 300                                data->model &= ~R1MS_MASK;
 301                                data->trutherm |= (TT_OFF << TT1_SHIFT);
 302                        }
 303                } else {
 304                        data->trutherm &= ~(TT_MASK << TT2_SHIFT);
 305                        if (val == 1) {
 306                                data->model |= R2MS_MASK;
 307                                data->trutherm |= (TT_ON << TT2_SHIFT);
 308                        } else {
 309                                data->model &= ~R2MS_MASK;
 310                                data->trutherm |= (TT_OFF << TT2_SHIFT);
 311                        }
 312                }
 313                ret = i2c_smbus_write_byte_data(client,
 314                                                LM95241_REG_RW_REMOTE_MODEL,
 315                                                data->model);
 316                if (ret < 0)
 317                        break;
 318                ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 319                                                data->trutherm);
 320                break;
 321        default:
 322                ret = -EOPNOTSUPP;
 323                break;
 324        }
 325
 326        mutex_unlock(&data->update_lock);
 327
 328        return ret;
 329}
 330
 331static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
 332                         u32 attr, int channel, long val)
 333{
 334        switch (type) {
 335        case hwmon_chip:
 336                return lm95241_write_chip(dev, attr, channel, val);
 337        case hwmon_temp:
 338                return lm95241_write_temp(dev, attr, channel, val);
 339        default:
 340                return -EOPNOTSUPP;
 341        }
 342}
 343
 344static umode_t lm95241_is_visible(const void *data,
 345                                  enum hwmon_sensor_types type,
 346                                  u32 attr, int channel)
 347{
 348        switch (type) {
 349        case hwmon_chip:
 350                switch (attr) {
 351                case hwmon_chip_update_interval:
 352                        return S_IRUGO | S_IWUSR;
 353                }
 354                break;
 355        case hwmon_temp:
 356                switch (attr) {
 357                case hwmon_temp_input:
 358                        return S_IRUGO;
 359                case hwmon_temp_fault:
 360                        return S_IRUGO;
 361                case hwmon_temp_min:
 362                case hwmon_temp_max:
 363                case hwmon_temp_type:
 364                        return S_IRUGO | S_IWUSR;
 365                }
 366                break;
 367        default:
 368                break;
 369        }
 370        return 0;
 371}
 372
 373/* Return 0 if detection is successful, -ENODEV otherwise */
 374static int lm95241_detect(struct i2c_client *new_client,
 375                          struct i2c_board_info *info)
 376{
 377        struct i2c_adapter *adapter = new_client->adapter;
 378        const char *name;
 379        int mfg_id, chip_id;
 380
 381        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 382                return -ENODEV;
 383
 384        mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
 385        if (mfg_id != NATSEMI_MAN_ID)
 386                return -ENODEV;
 387
 388        chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
 389        switch (chip_id) {
 390        case LM95231_CHIP_ID:
 391                name = "lm95231";
 392                break;
 393        case LM95241_CHIP_ID:
 394                name = "lm95241";
 395                break;
 396        default:
 397                return -ENODEV;
 398        }
 399
 400        /* Fill the i2c board info */
 401        strlcpy(info->type, name, I2C_NAME_SIZE);
 402        return 0;
 403}
 404
 405static void lm95241_init_client(struct i2c_client *client,
 406                                struct lm95241_data *data)
 407{
 408        data->interval = 1000;
 409        data->config = CFG_CR1000;
 410        data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 411
 412        i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 413        i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 414                                  R1FE_MASK | R2FE_MASK);
 415        i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 416                                  data->trutherm);
 417        i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 418                                  data->model);
 419}
 420
 421static const u32 lm95241_chip_config[] = {
 422        HWMON_C_UPDATE_INTERVAL,
 423        0
 424};
 425
 426static const struct hwmon_channel_info lm95241_chip = {
 427        .type = hwmon_chip,
 428        .config = lm95241_chip_config,
 429};
 430
 431static const u32 lm95241_temp_config[] = {
 432        HWMON_T_INPUT,
 433        HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | HWMON_T_TYPE |
 434                HWMON_T_FAULT,
 435        HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | HWMON_T_TYPE |
 436                HWMON_T_FAULT,
 437        0
 438};
 439
 440static const struct hwmon_channel_info lm95241_temp = {
 441        .type = hwmon_temp,
 442        .config = lm95241_temp_config,
 443};
 444
 445static const struct hwmon_channel_info *lm95241_info[] = {
 446        &lm95241_chip,
 447        &lm95241_temp,
 448        NULL
 449};
 450
 451static const struct hwmon_ops lm95241_hwmon_ops = {
 452        .is_visible = lm95241_is_visible,
 453        .read = lm95241_read,
 454        .write = lm95241_write,
 455};
 456
 457static const struct hwmon_chip_info lm95241_chip_info = {
 458        .ops = &lm95241_hwmon_ops,
 459        .info = lm95241_info,
 460};
 461
 462static int lm95241_probe(struct i2c_client *client,
 463                         const struct i2c_device_id *id)
 464{
 465        struct device *dev = &client->dev;
 466        struct lm95241_data *data;
 467        struct device *hwmon_dev;
 468
 469        data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
 470        if (!data)
 471                return -ENOMEM;
 472
 473        data->client = client;
 474        mutex_init(&data->update_lock);
 475
 476        /* Initialize the LM95241 chip */
 477        lm95241_init_client(client, data);
 478
 479        hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 480                                                           data,
 481                                                           &lm95241_chip_info,
 482                                                           NULL);
 483        return PTR_ERR_OR_ZERO(hwmon_dev);
 484}
 485
 486/* Driver data (common to all clients) */
 487static const struct i2c_device_id lm95241_id[] = {
 488        { "lm95231", 0 },
 489        { "lm95241", 0 },
 490        { }
 491};
 492MODULE_DEVICE_TABLE(i2c, lm95241_id);
 493
 494static struct i2c_driver lm95241_driver = {
 495        .class          = I2C_CLASS_HWMON,
 496        .driver = {
 497                .name   = DEVNAME,
 498        },
 499        .probe          = lm95241_probe,
 500        .id_table       = lm95241_id,
 501        .detect         = lm95241_detect,
 502        .address_list   = normal_i2c,
 503};
 504
 505module_i2c_driver(lm95241_driver);
 506
 507MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 508MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
 509MODULE_LICENSE("GPL");
 510