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 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24#include <linux/module.h>
  25#include <linux/init.h>
  26#include <linux/slab.h>
  27#include <linux/jiffies.h>
  28#include <linux/i2c.h>
  29#include <linux/hwmon.h>
  30#include <linux/hwmon-sysfs.h>
  31#include <linux/err.h>
  32#include <linux/mutex.h>
  33#include <linux/sysfs.h>
  34
  35#define DEVNAME "lm95241"
  36
  37static const unsigned short normal_i2c[] = {
  38        0x19, 0x2a, 0x2b, I2C_CLIENT_END };
  39
  40/* LM95241 registers */
  41#define LM95241_REG_R_MAN_ID            0xFE
  42#define LM95241_REG_R_CHIP_ID           0xFF
  43#define LM95241_REG_R_STATUS            0x02
  44#define LM95241_REG_RW_CONFIG           0x03
  45#define LM95241_REG_RW_REM_FILTER       0x06
  46#define LM95241_REG_RW_TRUTHERM         0x07
  47#define LM95241_REG_W_ONE_SHOT          0x0F
  48#define LM95241_REG_R_LOCAL_TEMPH       0x10
  49#define LM95241_REG_R_REMOTE1_TEMPH     0x11
  50#define LM95241_REG_R_REMOTE2_TEMPH     0x12
  51#define LM95241_REG_R_LOCAL_TEMPL       0x20
  52#define LM95241_REG_R_REMOTE1_TEMPL     0x21
  53#define LM95241_REG_R_REMOTE2_TEMPL     0x22
  54#define LM95241_REG_RW_REMOTE_MODEL     0x30
  55
  56/* LM95241 specific bitfields */
  57#define CFG_STOP 0x40
  58#define CFG_CR0076 0x00
  59#define CFG_CR0182 0x10
  60#define CFG_CR1000 0x20
  61#define CFG_CR2700 0x30
  62#define R1MS_SHIFT 0
  63#define R2MS_SHIFT 2
  64#define R1MS_MASK (0x01 << (R1MS_SHIFT))
  65#define R2MS_MASK (0x01 << (R2MS_SHIFT))
  66#define R1DF_SHIFT 1
  67#define R2DF_SHIFT 2
  68#define R1DF_MASK (0x01 << (R1DF_SHIFT))
  69#define R2DF_MASK (0x01 << (R2DF_SHIFT))
  70#define R1FE_MASK 0x01
  71#define R2FE_MASK 0x05
  72#define TT1_SHIFT 0
  73#define TT2_SHIFT 4
  74#define TT_OFF 0
  75#define TT_ON 1
  76#define TT_MASK 7
  77#define NATSEMI_MAN_ID  0x01
  78#define LM95231_CHIP_ID 0xA1
  79#define LM95241_CHIP_ID 0xA4
  80
  81static const u8 lm95241_reg_address[] = {
  82        LM95241_REG_R_LOCAL_TEMPH,
  83        LM95241_REG_R_LOCAL_TEMPL,
  84        LM95241_REG_R_REMOTE1_TEMPH,
  85        LM95241_REG_R_REMOTE1_TEMPL,
  86        LM95241_REG_R_REMOTE2_TEMPH,
  87        LM95241_REG_R_REMOTE2_TEMPL
  88};
  89
  90/* Client data (each client gets its own) */
  91struct lm95241_data {
  92        struct device *hwmon_dev;
  93        struct mutex update_lock;
  94        unsigned long last_updated, interval;   /* in jiffies */
  95        char valid;             /* zero until following fields are valid */
  96        /* registers values */
  97        u8 temp[ARRAY_SIZE(lm95241_reg_address)];
  98        u8 config, model, trutherm;
  99};
 100
 101/* Conversions */
 102static int temp_from_reg_signed(u8 val_h, u8 val_l)
 103{
 104        s16 val_hl = (val_h << 8) | val_l;
 105        return val_hl * 1000 / 256;
 106}
 107
 108static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 109{
 110        u16 val_hl = (val_h << 8) | val_l;
 111        return val_hl * 1000 / 256;
 112}
 113
 114static struct lm95241_data *lm95241_update_device(struct device *dev)
 115{
 116        struct i2c_client *client = to_i2c_client(dev);
 117        struct lm95241_data *data = i2c_get_clientdata(client);
 118
 119        mutex_lock(&data->update_lock);
 120
 121        if (time_after(jiffies, data->last_updated + data->interval) ||
 122            !data->valid) {
 123                int i;
 124
 125                dev_dbg(&client->dev, "Updating lm95241 data.\n");
 126                for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
 127                        data->temp[i]
 128                          = i2c_smbus_read_byte_data(client,
 129                                                     lm95241_reg_address[i]);
 130                data->last_updated = jiffies;
 131                data->valid = 1;
 132        }
 133
 134        mutex_unlock(&data->update_lock);
 135
 136        return data;
 137}
 138
 139/* Sysfs stuff */
 140static ssize_t show_input(struct device *dev, struct device_attribute *attr,
 141                          char *buf)
 142{
 143        struct lm95241_data *data = lm95241_update_device(dev);
 144        int index = to_sensor_dev_attr(attr)->index;
 145
 146        return snprintf(buf, PAGE_SIZE - 1, "%d\n",
 147                        index == 0 || (data->config & (1 << (index / 2))) ?
 148                temp_from_reg_signed(data->temp[index], data->temp[index + 1]) :
 149                temp_from_reg_unsigned(data->temp[index],
 150                                       data->temp[index + 1]));
 151}
 152
 153static ssize_t show_type(struct device *dev, struct device_attribute *attr,
 154                         char *buf)
 155{
 156        struct i2c_client *client = to_i2c_client(dev);
 157        struct lm95241_data *data = i2c_get_clientdata(client);
 158
 159        return snprintf(buf, PAGE_SIZE - 1,
 160                data->model & to_sensor_dev_attr(attr)->index ? "1\n" : "2\n");
 161}
 162
 163static ssize_t set_type(struct device *dev, struct device_attribute *attr,
 164                        const char *buf, size_t count)
 165{
 166        struct i2c_client *client = to_i2c_client(dev);
 167        struct lm95241_data *data = i2c_get_clientdata(client);
 168        unsigned long val;
 169        int shift;
 170        u8 mask = to_sensor_dev_attr(attr)->index;
 171
 172        if (kstrtoul(buf, 10, &val) < 0)
 173                return -EINVAL;
 174        if (val != 1 && val != 2)
 175                return -EINVAL;
 176
 177        shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;
 178
 179        mutex_lock(&data->update_lock);
 180
 181        data->trutherm &= ~(TT_MASK << shift);
 182        if (val == 1) {
 183                data->model |= mask;
 184                data->trutherm |= (TT_ON << shift);
 185        } else {
 186                data->model &= ~mask;
 187                data->trutherm |= (TT_OFF << shift);
 188        }
 189        data->valid = 0;
 190
 191        i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 192                                  data->model);
 193        i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 194                                  data->trutherm);
 195
 196        mutex_unlock(&data->update_lock);
 197
 198        return count;
 199}
 200
 201static ssize_t show_min(struct device *dev, struct device_attribute *attr,
 202                        char *buf)
 203{
 204        struct i2c_client *client = to_i2c_client(dev);
 205        struct lm95241_data *data = i2c_get_clientdata(client);
 206
 207        return snprintf(buf, PAGE_SIZE - 1,
 208                        data->config & to_sensor_dev_attr(attr)->index ?
 209                        "-127000\n" : "0\n");
 210}
 211
 212static ssize_t set_min(struct device *dev, struct device_attribute *attr,
 213                       const char *buf, size_t count)
 214{
 215        struct i2c_client *client = to_i2c_client(dev);
 216        struct lm95241_data *data = i2c_get_clientdata(client);
 217        long val;
 218
 219        if (kstrtol(buf, 10, &val) < 0)
 220                return -EINVAL;
 221        if (val < -128000)
 222                return -EINVAL;
 223
 224        mutex_lock(&data->update_lock);
 225
 226        if (val < 0)
 227                data->config |= to_sensor_dev_attr(attr)->index;
 228        else
 229                data->config &= ~to_sensor_dev_attr(attr)->index;
 230        data->valid = 0;
 231
 232        i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 233
 234        mutex_unlock(&data->update_lock);
 235
 236        return count;
 237}
 238
 239static ssize_t show_max(struct device *dev, struct device_attribute *attr,
 240                        char *buf)
 241{
 242        struct i2c_client *client = to_i2c_client(dev);
 243        struct lm95241_data *data = i2c_get_clientdata(client);
 244
 245        return snprintf(buf, PAGE_SIZE - 1,
 246                        data->config & to_sensor_dev_attr(attr)->index ?
 247                        "127000\n" : "255000\n");
 248}
 249
 250static ssize_t set_max(struct device *dev, struct device_attribute *attr,
 251                       const char *buf, size_t count)
 252{
 253        struct i2c_client *client = to_i2c_client(dev);
 254        struct lm95241_data *data = i2c_get_clientdata(client);
 255        long val;
 256
 257        if (kstrtol(buf, 10, &val) < 0)
 258                return -EINVAL;
 259        if (val >= 256000)
 260                return -EINVAL;
 261
 262        mutex_lock(&data->update_lock);
 263
 264        if (val <= 127000)
 265                data->config |= to_sensor_dev_attr(attr)->index;
 266        else
 267                data->config &= ~to_sensor_dev_attr(attr)->index;
 268        data->valid = 0;
 269
 270        i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 271
 272        mutex_unlock(&data->update_lock);
 273
 274        return count;
 275}
 276
 277static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
 278                             char *buf)
 279{
 280        struct lm95241_data *data = lm95241_update_device(dev);
 281
 282        return snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval
 283                        / HZ);
 284}
 285
 286static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
 287                            const char *buf, size_t count)
 288{
 289        struct i2c_client *client = to_i2c_client(dev);
 290        struct lm95241_data *data = i2c_get_clientdata(client);
 291        unsigned long val;
 292
 293        if (kstrtoul(buf, 10, &val) < 0)
 294                return -EINVAL;
 295
 296        data->interval = val * HZ / 1000;
 297
 298        return count;
 299}
 300
 301static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
 302static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
 303static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
 304static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
 305                          R1MS_MASK);
 306static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
 307                          R2MS_MASK);
 308static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
 309                          R1DF_MASK);
 310static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
 311                          R2DF_MASK);
 312static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
 313                          R1DF_MASK);
 314static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
 315                          R2DF_MASK);
 316static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
 317                   set_interval);
 318
 319static struct attribute *lm95241_attributes[] = {
 320        &sensor_dev_attr_temp1_input.dev_attr.attr,
 321        &sensor_dev_attr_temp2_input.dev_attr.attr,
 322        &sensor_dev_attr_temp3_input.dev_attr.attr,
 323        &sensor_dev_attr_temp2_type.dev_attr.attr,
 324        &sensor_dev_attr_temp3_type.dev_attr.attr,
 325        &sensor_dev_attr_temp2_min.dev_attr.attr,
 326        &sensor_dev_attr_temp3_min.dev_attr.attr,
 327        &sensor_dev_attr_temp2_max.dev_attr.attr,
 328        &sensor_dev_attr_temp3_max.dev_attr.attr,
 329        &dev_attr_update_interval.attr,
 330        NULL
 331};
 332
 333static const struct attribute_group lm95241_group = {
 334        .attrs = lm95241_attributes,
 335};
 336
 337/* Return 0 if detection is successful, -ENODEV otherwise */
 338static int lm95241_detect(struct i2c_client *new_client,
 339                          struct i2c_board_info *info)
 340{
 341        struct i2c_adapter *adapter = new_client->adapter;
 342        const char *name;
 343        int mfg_id, chip_id;
 344
 345        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 346                return -ENODEV;
 347
 348        mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
 349        if (mfg_id != NATSEMI_MAN_ID)
 350                return -ENODEV;
 351
 352        chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
 353        switch (chip_id) {
 354        case LM95231_CHIP_ID:
 355                name = "lm95231";
 356                break;
 357        case LM95241_CHIP_ID:
 358                name = "lm95241";
 359                break;
 360        default:
 361                return -ENODEV;
 362        }
 363
 364        /* Fill the i2c board info */
 365        strlcpy(info->type, name, I2C_NAME_SIZE);
 366        return 0;
 367}
 368
 369static void lm95241_init_client(struct i2c_client *client)
 370{
 371        struct lm95241_data *data = i2c_get_clientdata(client);
 372
 373        data->interval = HZ;    /* 1 sec default */
 374        data->valid = 0;
 375        data->config = CFG_CR0076;
 376        data->model = 0;
 377        data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 378
 379        i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 380        i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 381                                  R1FE_MASK | R2FE_MASK);
 382        i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 383                                  data->trutherm);
 384        i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 385                                  data->model);
 386}
 387
 388static int lm95241_probe(struct i2c_client *new_client,
 389                         const struct i2c_device_id *id)
 390{
 391        struct lm95241_data *data;
 392        int err;
 393
 394        data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
 395        if (!data) {
 396                err = -ENOMEM;
 397                goto exit;
 398        }
 399
 400        i2c_set_clientdata(new_client, data);
 401        mutex_init(&data->update_lock);
 402
 403        /* Initialize the LM95241 chip */
 404        lm95241_init_client(new_client);
 405
 406        /* Register sysfs hooks */
 407        err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
 408        if (err)
 409                goto exit_free;
 410
 411        data->hwmon_dev = hwmon_device_register(&new_client->dev);
 412        if (IS_ERR(data->hwmon_dev)) {
 413                err = PTR_ERR(data->hwmon_dev);
 414                goto exit_remove_files;
 415        }
 416
 417        return 0;
 418
 419exit_remove_files:
 420        sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
 421exit_free:
 422        kfree(data);
 423exit:
 424        return err;
 425}
 426
 427static int lm95241_remove(struct i2c_client *client)
 428{
 429        struct lm95241_data *data = i2c_get_clientdata(client);
 430
 431        hwmon_device_unregister(data->hwmon_dev);
 432        sysfs_remove_group(&client->dev.kobj, &lm95241_group);
 433
 434        kfree(data);
 435        return 0;
 436}
 437
 438/* Driver data (common to all clients) */
 439static const struct i2c_device_id lm95241_id[] = {
 440        { "lm95231", 0 },
 441        { "lm95241", 0 },
 442        { }
 443};
 444MODULE_DEVICE_TABLE(i2c, lm95241_id);
 445
 446static struct i2c_driver lm95241_driver = {
 447        .class          = I2C_CLASS_HWMON,
 448        .driver = {
 449                .name   = DEVNAME,
 450        },
 451        .probe          = lm95241_probe,
 452        .remove         = lm95241_remove,
 453        .id_table       = lm95241_id,
 454        .detect         = lm95241_detect,
 455        .address_list   = normal_i2c,
 456};
 457
 458module_i2c_driver(lm95241_driver);
 459
 460MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 461MODULE_DESCRIPTION("LM95241 sensor driver");
 462MODULE_LICENSE("GPL");
 463
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