linux/drivers/hwmon/max1668.c
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   1/*
   2 * Copyright (c) 2011 David George <david.george@ska.ac.za>
   3 *
   4 * based on adm1021.c
   5 * some credit to Christoph Scheurer, but largely a rewrite
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22#include <linux/module.h>
  23#include <linux/init.h>
  24#include <linux/slab.h>
  25#include <linux/jiffies.h>
  26#include <linux/i2c.h>
  27#include <linux/hwmon.h>
  28#include <linux/hwmon-sysfs.h>
  29#include <linux/err.h>
  30#include <linux/mutex.h>
  31
  32/* Addresses to scan */
  33static unsigned short max1668_addr_list[] = {
  34        0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
  35
  36/* max1668 registers */
  37
  38#define MAX1668_REG_TEMP(nr)    (nr)
  39#define MAX1668_REG_STAT1       0x05
  40#define MAX1668_REG_STAT2       0x06
  41#define MAX1668_REG_MAN_ID      0xfe
  42#define MAX1668_REG_DEV_ID      0xff
  43
  44/* limits */
  45
  46/* write high limits */
  47#define MAX1668_REG_LIMH_WR(nr) (0x13 + 2 * (nr))
  48/* write low limits */
  49#define MAX1668_REG_LIML_WR(nr) (0x14 + 2 * (nr))
  50/* read high limits */
  51#define MAX1668_REG_LIMH_RD(nr) (0x08 + 2 * (nr))
  52/* read low limits */
  53#define MAX1668_REG_LIML_RD(nr) (0x09 + 2 * (nr))
  54
  55/* manufacturer and device ID Constants */
  56#define MAN_ID_MAXIM            0x4d
  57#define DEV_ID_MAX1668          0x3
  58#define DEV_ID_MAX1805          0x5
  59#define DEV_ID_MAX1989          0xb
  60
  61/* read only mode module parameter */
  62static bool read_only;
  63module_param(read_only, bool, 0);
  64MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");
  65
  66enum chips { max1668, max1805, max1989 };
  67
  68struct max1668_data {
  69        struct device *hwmon_dev;
  70        enum chips type;
  71
  72        struct mutex update_lock;
  73        char valid;             /* !=0 if following fields are valid */
  74        unsigned long last_updated;     /* In jiffies */
  75
  76        /* 1x local and 4x remote */
  77        s8 temp_max[5];
  78        s8 temp_min[5];
  79        s8 temp[5];
  80        u16 alarms;
  81};
  82
  83static struct max1668_data *max1668_update_device(struct device *dev)
  84{
  85        struct i2c_client *client = to_i2c_client(dev);
  86        struct max1668_data *data = i2c_get_clientdata(client);
  87        struct max1668_data *ret = data;
  88        s32 val;
  89        int i;
  90
  91        mutex_lock(&data->update_lock);
  92
  93        if (data->valid && !time_after(jiffies,
  94                        data->last_updated + HZ + HZ / 2))
  95                goto abort;
  96
  97        for (i = 0; i < 5; i++) {
  98                val = i2c_smbus_read_byte_data(client, MAX1668_REG_TEMP(i));
  99                if (unlikely(val < 0)) {
 100                        ret = ERR_PTR(val);
 101                        goto abort;
 102                }
 103                data->temp[i] = (s8) val;
 104
 105                val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIMH_RD(i));
 106                if (unlikely(val < 0)) {
 107                        ret = ERR_PTR(val);
 108                        goto abort;
 109                }
 110                data->temp_max[i] = (s8) val;
 111
 112                val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIML_RD(i));
 113                if (unlikely(val < 0)) {
 114                        ret = ERR_PTR(val);
 115                        goto abort;
 116                }
 117                data->temp_min[i] = (s8) val;
 118        }
 119
 120        val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT1);
 121        if (unlikely(val < 0)) {
 122                ret = ERR_PTR(val);
 123                goto abort;
 124        }
 125        data->alarms = val << 8;
 126
 127        val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT2);
 128        if (unlikely(val < 0)) {
 129                ret = ERR_PTR(val);
 130                goto abort;
 131        }
 132        data->alarms |= val;
 133
 134        data->last_updated = jiffies;
 135        data->valid = 1;
 136abort:
 137        mutex_unlock(&data->update_lock);
 138
 139        return ret;
 140}
 141
 142static ssize_t show_temp(struct device *dev,
 143                         struct device_attribute *devattr, char *buf)
 144{
 145        int index = to_sensor_dev_attr(devattr)->index;
 146        struct max1668_data *data = max1668_update_device(dev);
 147
 148        if (IS_ERR(data))
 149                return PTR_ERR(data);
 150
 151        return sprintf(buf, "%d\n", data->temp[index] * 1000);
 152}
 153
 154static ssize_t show_temp_max(struct device *dev,
 155                             struct device_attribute *devattr, char *buf)
 156{
 157        int index = to_sensor_dev_attr(devattr)->index;
 158        struct max1668_data *data = max1668_update_device(dev);
 159
 160        if (IS_ERR(data))
 161                return PTR_ERR(data);
 162
 163        return sprintf(buf, "%d\n", data->temp_max[index] * 1000);
 164}
 165
 166static ssize_t show_temp_min(struct device *dev,
 167                             struct device_attribute *devattr, char *buf)
 168{
 169        int index = to_sensor_dev_attr(devattr)->index;
 170        struct max1668_data *data = max1668_update_device(dev);
 171
 172        if (IS_ERR(data))
 173                return PTR_ERR(data);
 174
 175        return sprintf(buf, "%d\n", data->temp_min[index] * 1000);
 176}
 177
 178static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
 179                          char *buf)
 180{
 181        int index = to_sensor_dev_attr(attr)->index;
 182        struct max1668_data *data = max1668_update_device(dev);
 183
 184        if (IS_ERR(data))
 185                return PTR_ERR(data);
 186
 187        return sprintf(buf, "%u\n", (data->alarms >> index) & 0x1);
 188}
 189
 190static ssize_t show_fault(struct device *dev,
 191                          struct device_attribute *devattr, char *buf)
 192{
 193        int index = to_sensor_dev_attr(devattr)->index;
 194        struct max1668_data *data = max1668_update_device(dev);
 195
 196        if (IS_ERR(data))
 197                return PTR_ERR(data);
 198
 199        return sprintf(buf, "%u\n",
 200                       (data->alarms & (1 << 12)) && data->temp[index] == 127);
 201}
 202
 203static ssize_t set_temp_max(struct device *dev,
 204                            struct device_attribute *devattr,
 205                            const char *buf, size_t count)
 206{
 207        int index = to_sensor_dev_attr(devattr)->index;
 208        struct i2c_client *client = to_i2c_client(dev);
 209        struct max1668_data *data = i2c_get_clientdata(client);
 210        long temp;
 211        int ret;
 212
 213        ret = kstrtol(buf, 10, &temp);
 214        if (ret < 0)
 215                return ret;
 216
 217        mutex_lock(&data->update_lock);
 218        data->temp_max[index] = SENSORS_LIMIT(temp/1000, -128, 127);
 219        if (i2c_smbus_write_byte_data(client,
 220                                        MAX1668_REG_LIMH_WR(index),
 221                                        data->temp_max[index]))
 222                count = -EIO;
 223        mutex_unlock(&data->update_lock);
 224
 225        return count;
 226}
 227
 228static ssize_t set_temp_min(struct device *dev,
 229                            struct device_attribute *devattr,
 230                            const char *buf, size_t count)
 231{
 232        int index = to_sensor_dev_attr(devattr)->index;
 233        struct i2c_client *client = to_i2c_client(dev);
 234        struct max1668_data *data = i2c_get_clientdata(client);
 235        long temp;
 236        int ret;
 237
 238        ret = kstrtol(buf, 10, &temp);
 239        if (ret < 0)
 240                return ret;
 241
 242        mutex_lock(&data->update_lock);
 243        data->temp_min[index] = SENSORS_LIMIT(temp/1000, -128, 127);
 244        if (i2c_smbus_write_byte_data(client,
 245                                        MAX1668_REG_LIML_WR(index),
 246                                        data->temp_max[index]))
 247                count = -EIO;
 248        mutex_unlock(&data->update_lock);
 249
 250        return count;
 251}
 252
 253static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 254static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp_max,
 255                                set_temp_max, 0);
 256static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp_min,
 257                                set_temp_min, 0);
 258static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 259static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO, show_temp_max,
 260                                set_temp_max, 1);
 261static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO, show_temp_min,
 262                                set_temp_min, 1);
 263static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 264static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO, show_temp_max,
 265                                set_temp_max, 2);
 266static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO, show_temp_min,
 267                                set_temp_min, 2);
 268static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 269static SENSOR_DEVICE_ATTR(temp4_max, S_IRUGO, show_temp_max,
 270                                set_temp_max, 3);
 271static SENSOR_DEVICE_ATTR(temp4_min, S_IRUGO, show_temp_min,
 272                                set_temp_min, 3);
 273static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO, show_temp, NULL, 4);
 274static SENSOR_DEVICE_ATTR(temp5_max, S_IRUGO, show_temp_max,
 275                                set_temp_max, 4);
 276static SENSOR_DEVICE_ATTR(temp5_min, S_IRUGO, show_temp_min,
 277                                set_temp_min, 4);
 278
 279static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 14);
 280static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 13);
 281static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 7);
 282static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 6);
 283static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 5);
 284static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
 285static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_alarm, NULL, 3);
 286static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 2);
 287static SENSOR_DEVICE_ATTR(temp5_min_alarm, S_IRUGO, show_alarm, NULL, 1);
 288static SENSOR_DEVICE_ATTR(temp5_max_alarm, S_IRUGO, show_alarm, NULL, 0);
 289
 290static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
 291static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
 292static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
 293static SENSOR_DEVICE_ATTR(temp5_fault, S_IRUGO, show_fault, NULL, 4);
 294
 295/* Attributes common to MAX1668, MAX1989 and MAX1805 */
 296static struct attribute *max1668_attribute_common[] = {
 297        &sensor_dev_attr_temp1_max.dev_attr.attr,
 298        &sensor_dev_attr_temp1_min.dev_attr.attr,
 299        &sensor_dev_attr_temp1_input.dev_attr.attr,
 300        &sensor_dev_attr_temp2_max.dev_attr.attr,
 301        &sensor_dev_attr_temp2_min.dev_attr.attr,
 302        &sensor_dev_attr_temp2_input.dev_attr.attr,
 303        &sensor_dev_attr_temp3_max.dev_attr.attr,
 304        &sensor_dev_attr_temp3_min.dev_attr.attr,
 305        &sensor_dev_attr_temp3_input.dev_attr.attr,
 306
 307        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 308        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 309        &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 310        &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 311        &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 312        &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
 313
 314        &sensor_dev_attr_temp2_fault.dev_attr.attr,
 315        &sensor_dev_attr_temp3_fault.dev_attr.attr,
 316        NULL
 317};
 318
 319/* Attributes not present on MAX1805 */
 320static struct attribute *max1668_attribute_unique[] = {
 321        &sensor_dev_attr_temp4_max.dev_attr.attr,
 322        &sensor_dev_attr_temp4_min.dev_attr.attr,
 323        &sensor_dev_attr_temp4_input.dev_attr.attr,
 324        &sensor_dev_attr_temp5_max.dev_attr.attr,
 325        &sensor_dev_attr_temp5_min.dev_attr.attr,
 326        &sensor_dev_attr_temp5_input.dev_attr.attr,
 327
 328        &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
 329        &sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
 330        &sensor_dev_attr_temp5_max_alarm.dev_attr.attr,
 331        &sensor_dev_attr_temp5_min_alarm.dev_attr.attr,
 332
 333        &sensor_dev_attr_temp4_fault.dev_attr.attr,
 334        &sensor_dev_attr_temp5_fault.dev_attr.attr,
 335        NULL
 336};
 337
 338static umode_t max1668_attribute_mode(struct kobject *kobj,
 339                                     struct attribute *attr, int index)
 340{
 341        umode_t ret = S_IRUGO;
 342        if (read_only)
 343                return ret;
 344        if (attr == &sensor_dev_attr_temp1_max.dev_attr.attr ||
 345            attr == &sensor_dev_attr_temp2_max.dev_attr.attr ||
 346            attr == &sensor_dev_attr_temp3_max.dev_attr.attr ||
 347            attr == &sensor_dev_attr_temp4_max.dev_attr.attr ||
 348            attr == &sensor_dev_attr_temp5_max.dev_attr.attr ||
 349            attr == &sensor_dev_attr_temp1_min.dev_attr.attr ||
 350            attr == &sensor_dev_attr_temp2_min.dev_attr.attr ||
 351            attr == &sensor_dev_attr_temp3_min.dev_attr.attr ||
 352            attr == &sensor_dev_attr_temp4_min.dev_attr.attr ||
 353            attr == &sensor_dev_attr_temp5_min.dev_attr.attr)
 354                ret |= S_IWUSR;
 355        return ret;
 356}
 357
 358static const struct attribute_group max1668_group_common = {
 359        .attrs = max1668_attribute_common,
 360        .is_visible = max1668_attribute_mode
 361};
 362
 363static const struct attribute_group max1668_group_unique = {
 364        .attrs = max1668_attribute_unique,
 365        .is_visible = max1668_attribute_mode
 366};
 367
 368/* Return 0 if detection is successful, -ENODEV otherwise */
 369static int max1668_detect(struct i2c_client *client,
 370                          struct i2c_board_info *info)
 371{
 372        struct i2c_adapter *adapter = client->adapter;
 373        const char *type_name;
 374        int man_id, dev_id;
 375
 376        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 377                return -ENODEV;
 378
 379        /* Check for unsupported part */
 380        man_id = i2c_smbus_read_byte_data(client, MAX1668_REG_MAN_ID);
 381        if (man_id != MAN_ID_MAXIM)
 382                return -ENODEV;
 383
 384        dev_id = i2c_smbus_read_byte_data(client, MAX1668_REG_DEV_ID);
 385        if (dev_id < 0)
 386                return -ENODEV;
 387
 388        type_name = NULL;
 389        if (dev_id == DEV_ID_MAX1668)
 390                type_name = "max1668";
 391        else if (dev_id == DEV_ID_MAX1805)
 392                type_name = "max1805";
 393        else if (dev_id == DEV_ID_MAX1989)
 394                type_name = "max1989";
 395
 396        if (!type_name)
 397                return -ENODEV;
 398
 399        strlcpy(info->type, type_name, I2C_NAME_SIZE);
 400
 401        return 0;
 402}
 403
 404static int max1668_probe(struct i2c_client *client,
 405                         const struct i2c_device_id *id)
 406{
 407        struct i2c_adapter *adapter = client->adapter;
 408        struct max1668_data *data;
 409        int err;
 410
 411        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 412                return -ENODEV;
 413
 414        data = devm_kzalloc(&client->dev, sizeof(struct max1668_data),
 415                            GFP_KERNEL);
 416        if (!data)
 417                return -ENOMEM;
 418
 419        i2c_set_clientdata(client, data);
 420        data->type = id->driver_data;
 421        mutex_init(&data->update_lock);
 422
 423        /* Register sysfs hooks */
 424        err = sysfs_create_group(&client->dev.kobj, &max1668_group_common);
 425        if (err)
 426                return err;
 427
 428        if (data->type == max1668 || data->type == max1989) {
 429                err = sysfs_create_group(&client->dev.kobj,
 430                                         &max1668_group_unique);
 431                if (err)
 432                        goto error_sysrem0;
 433        }
 434
 435        data->hwmon_dev = hwmon_device_register(&client->dev);
 436        if (IS_ERR(data->hwmon_dev)) {
 437                err = PTR_ERR(data->hwmon_dev);
 438                goto error_sysrem1;
 439        }
 440
 441        return 0;
 442
 443error_sysrem1:
 444        if (data->type == max1668 || data->type == max1989)
 445                sysfs_remove_group(&client->dev.kobj, &max1668_group_unique);
 446error_sysrem0:
 447        sysfs_remove_group(&client->dev.kobj, &max1668_group_common);
 448        return err;
 449}
 450
 451static int max1668_remove(struct i2c_client *client)
 452{
 453        struct max1668_data *data = i2c_get_clientdata(client);
 454
 455        hwmon_device_unregister(data->hwmon_dev);
 456        if (data->type == max1668 || data->type == max1989)
 457                sysfs_remove_group(&client->dev.kobj, &max1668_group_unique);
 458
 459        sysfs_remove_group(&client->dev.kobj, &max1668_group_common);
 460
 461        return 0;
 462}
 463
 464static const struct i2c_device_id max1668_id[] = {
 465        { "max1668", max1668 },
 466        { "max1805", max1805 },
 467        { "max1989", max1989 },
 468        { }
 469};
 470MODULE_DEVICE_TABLE(i2c, max1668_id);
 471
 472/* This is the driver that will be inserted */
 473static struct i2c_driver max1668_driver = {
 474        .class = I2C_CLASS_HWMON,
 475        .driver = {
 476                  .name = "max1668",
 477                  },
 478        .probe = max1668_probe,
 479        .remove = max1668_remove,
 480        .id_table = max1668_id,
 481        .detect = max1668_detect,
 482        .address_list = max1668_addr_list,
 483};
 484
 485module_i2c_driver(max1668_driver);
 486
 487MODULE_AUTHOR("David George <david.george@ska.ac.za>");
 488MODULE_DESCRIPTION("MAX1668 remote temperature sensor driver");
 489MODULE_LICENSE("GPL");
 490
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