linux/drivers/hwmon/lm95241.c
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   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
  23static 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
  66static 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) */
  76struct 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 */
  88static 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
  94static 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
 100static 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
 129static 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
 143static 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
 186static 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
 199static 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
 238static 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
 322static 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
 335static 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 */
 365static 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        strlcpy(info->type, name, I2C_NAME_SIZE);
 393        return 0;
 394}
 395
 396static 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
 412static const struct hwmon_channel_info *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
 424static const struct hwmon_ops lm95241_hwmon_ops = {
 425        .is_visible = lm95241_is_visible,
 426        .read = lm95241_read,
 427        .write = lm95241_write,
 428};
 429
 430static const struct hwmon_chip_info lm95241_chip_info = {
 431        .ops = &lm95241_hwmon_ops,
 432        .info = lm95241_info,
 433};
 434
 435static 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) */
 459static const struct i2c_device_id lm95241_id[] = {
 460        { "lm95231", 0 },
 461        { "lm95241", 0 },
 462        { }
 463};
 464MODULE_DEVICE_TABLE(i2c, lm95241_id);
 465
 466static 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
 477module_i2c_driver(lm95241_driver);
 478
 479MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 480MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
 481MODULE_LICENSE("GPL");
 482