linux/drivers/hwmon/adt7410.c
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   1/*
   2 * adt7410.c - Part of lm_sensors, Linux kernel modules for hardware
   3 *       monitoring
   4 * This driver handles the ADT7410 and compatible digital temperature sensors.
   5 * Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
   6 * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
   7 * and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>
   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/delay.h>
  34
  35/*
  36 * ADT7410 registers definition
  37 */
  38
  39#define ADT7410_TEMPERATURE             0
  40#define ADT7410_STATUS                  2
  41#define ADT7410_CONFIG                  3
  42#define ADT7410_T_ALARM_HIGH            4
  43#define ADT7410_T_ALARM_LOW             6
  44#define ADT7410_T_CRIT                  8
  45#define ADT7410_T_HYST                  0xA
  46
  47/*
  48 * ADT7410 status
  49 */
  50#define ADT7410_STAT_T_LOW              (1 << 4)
  51#define ADT7410_STAT_T_HIGH             (1 << 5)
  52#define ADT7410_STAT_T_CRIT             (1 << 6)
  53#define ADT7410_STAT_NOT_RDY            (1 << 7)
  54
  55/*
  56 * ADT7410 config
  57 */
  58#define ADT7410_FAULT_QUEUE_MASK        (1 << 0 | 1 << 1)
  59#define ADT7410_CT_POLARITY             (1 << 2)
  60#define ADT7410_INT_POLARITY            (1 << 3)
  61#define ADT7410_EVENT_MODE              (1 << 4)
  62#define ADT7410_MODE_MASK               (1 << 5 | 1 << 6)
  63#define ADT7410_FULL                    (0 << 5 | 0 << 6)
  64#define ADT7410_PD                      (1 << 5 | 1 << 6)
  65#define ADT7410_RESOLUTION              (1 << 7)
  66
  67/*
  68 * ADT7410 masks
  69 */
  70#define ADT7410_T13_VALUE_MASK                  0xFFF8
  71#define ADT7410_T_HYST_MASK                     0xF
  72
  73/* straight from the datasheet */
  74#define ADT7410_TEMP_MIN (-55000)
  75#define ADT7410_TEMP_MAX 150000
  76
  77enum adt7410_type {             /* keep sorted in alphabetical order */
  78        adt7410,
  79};
  80
  81/* Addresses scanned */
  82static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
  83                                        I2C_CLIENT_END };
  84
  85static const u8 ADT7410_REG_TEMP[4] = {
  86        ADT7410_TEMPERATURE,            /* input */
  87        ADT7410_T_ALARM_HIGH,           /* high */
  88        ADT7410_T_ALARM_LOW,            /* low */
  89        ADT7410_T_CRIT,                 /* critical */
  90};
  91
  92/* Each client has this additional data */
  93struct adt7410_data {
  94        struct device           *hwmon_dev;
  95        struct mutex            update_lock;
  96        u8                      config;
  97        u8                      oldconfig;
  98        bool                    valid;          /* true if registers valid */
  99        unsigned long           last_updated;   /* In jiffies */
 100        s16                     temp[4];        /* Register values,
 101                                                   0 = input
 102                                                   1 = high
 103                                                   2 = low
 104                                                   3 = critical */
 105        u8                      hyst;           /* hysteresis offset */
 106};
 107
 108/*
 109 * adt7410 register access by I2C
 110 */
 111static int adt7410_temp_ready(struct i2c_client *client)
 112{
 113        int i, status;
 114
 115        for (i = 0; i < 6; i++) {
 116                status = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
 117                if (status < 0)
 118                        return status;
 119                if (!(status & ADT7410_STAT_NOT_RDY))
 120                        return 0;
 121                msleep(60);
 122        }
 123        return -ETIMEDOUT;
 124}
 125
 126static struct adt7410_data *adt7410_update_device(struct device *dev)
 127{
 128        struct i2c_client *client = to_i2c_client(dev);
 129        struct adt7410_data *data = i2c_get_clientdata(client);
 130        struct adt7410_data *ret = data;
 131        mutex_lock(&data->update_lock);
 132
 133        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 134            || !data->valid) {
 135                int i, status;
 136
 137                dev_dbg(&client->dev, "Starting update\n");
 138
 139                status = adt7410_temp_ready(client); /* check for new value */
 140                if (unlikely(status)) {
 141                        ret = ERR_PTR(status);
 142                        goto abort;
 143                }
 144                for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
 145                        status = i2c_smbus_read_word_swapped(client,
 146                                                        ADT7410_REG_TEMP[i]);
 147                        if (unlikely(status < 0)) {
 148                                dev_dbg(dev,
 149                                        "Failed to read value: reg %d, error %d\n",
 150                                        ADT7410_REG_TEMP[i], status);
 151                                ret = ERR_PTR(status);
 152                                goto abort;
 153                        }
 154                        data->temp[i] = status;
 155                }
 156                status = i2c_smbus_read_byte_data(client, ADT7410_T_HYST);
 157                if (unlikely(status < 0)) {
 158                        dev_dbg(dev,
 159                                "Failed to read value: reg %d, error %d\n",
 160                                ADT7410_T_HYST, status);
 161                        ret = ERR_PTR(status);
 162                        goto abort;
 163                }
 164                data->hyst = status;
 165                data->last_updated = jiffies;
 166                data->valid = true;
 167        }
 168
 169abort:
 170        mutex_unlock(&data->update_lock);
 171        return ret;
 172}
 173
 174static s16 ADT7410_TEMP_TO_REG(long temp)
 175{
 176        return DIV_ROUND_CLOSEST(SENSORS_LIMIT(temp, ADT7410_TEMP_MIN,
 177                                               ADT7410_TEMP_MAX) * 128, 1000);
 178}
 179
 180static int ADT7410_REG_TO_TEMP(struct adt7410_data *data, s16 reg)
 181{
 182        /* in 13 bit mode, bits 0-2 are status flags - mask them out */
 183        if (!(data->config & ADT7410_RESOLUTION))
 184                reg &= ADT7410_T13_VALUE_MASK;
 185        /*
 186         * temperature is stored in twos complement format, in steps of
 187         * 1/128°C
 188         */
 189        return DIV_ROUND_CLOSEST(reg * 1000, 128);
 190}
 191
 192/*-----------------------------------------------------------------------*/
 193
 194/* sysfs attributes for hwmon */
 195
 196static ssize_t adt7410_show_temp(struct device *dev,
 197                                 struct device_attribute *da, char *buf)
 198{
 199        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 200        struct adt7410_data *data = adt7410_update_device(dev);
 201
 202        if (IS_ERR(data))
 203                return PTR_ERR(data);
 204
 205        return sprintf(buf, "%d\n", ADT7410_REG_TO_TEMP(data,
 206                       data->temp[attr->index]));
 207}
 208
 209static ssize_t adt7410_set_temp(struct device *dev,
 210                                struct device_attribute *da,
 211                                const char *buf, size_t count)
 212{
 213        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 214        struct i2c_client *client = to_i2c_client(dev);
 215        struct adt7410_data *data = i2c_get_clientdata(client);
 216        int nr = attr->index;
 217        long temp;
 218        int ret;
 219
 220        ret = kstrtol(buf, 10, &temp);
 221        if (ret)
 222                return ret;
 223
 224        mutex_lock(&data->update_lock);
 225        data->temp[nr] = ADT7410_TEMP_TO_REG(temp);
 226        ret = i2c_smbus_write_word_swapped(client, ADT7410_REG_TEMP[nr],
 227                                           data->temp[nr]);
 228        if (ret)
 229                count = ret;
 230        mutex_unlock(&data->update_lock);
 231        return count;
 232}
 233
 234static ssize_t adt7410_show_t_hyst(struct device *dev,
 235                                   struct device_attribute *da,
 236                                   char *buf)
 237{
 238        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 239        struct adt7410_data *data;
 240        int nr = attr->index;
 241        int hyst;
 242
 243        data = adt7410_update_device(dev);
 244        if (IS_ERR(data))
 245                return PTR_ERR(data);
 246        hyst = (data->hyst & ADT7410_T_HYST_MASK) * 1000;
 247
 248        /*
 249         * hysteresis is stored as a 4 bit offset in the device, convert it
 250         * to an absolute value
 251         */
 252        if (nr == 2)    /* min has positive offset, others have negative */
 253                hyst = -hyst;
 254        return sprintf(buf, "%d\n",
 255                       ADT7410_REG_TO_TEMP(data, data->temp[nr]) - hyst);
 256}
 257
 258static ssize_t adt7410_set_t_hyst(struct device *dev,
 259                                  struct device_attribute *da,
 260                                  const char *buf, size_t count)
 261{
 262        struct i2c_client *client = to_i2c_client(dev);
 263        struct adt7410_data *data = i2c_get_clientdata(client);
 264        int limit, ret;
 265        long hyst;
 266
 267        ret = kstrtol(buf, 10, &hyst);
 268        if (ret)
 269                return ret;
 270        /* convert absolute hysteresis value to a 4 bit delta value */
 271        limit = ADT7410_REG_TO_TEMP(data, data->temp[1]);
 272        hyst = SENSORS_LIMIT(hyst, ADT7410_TEMP_MIN, ADT7410_TEMP_MAX);
 273        data->hyst = SENSORS_LIMIT(DIV_ROUND_CLOSEST(limit - hyst, 1000),
 274                                   0, ADT7410_T_HYST_MASK);
 275        ret = i2c_smbus_write_byte_data(client, ADT7410_T_HYST, data->hyst);
 276        if (ret)
 277                return ret;
 278
 279        return count;
 280}
 281
 282static ssize_t adt7410_show_alarm(struct device *dev,
 283                                  struct device_attribute *da,
 284                                  char *buf)
 285{
 286        struct i2c_client *client = to_i2c_client(dev);
 287        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 288        int ret;
 289
 290        ret = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
 291        if (ret < 0)
 292                return ret;
 293
 294        return sprintf(buf, "%d\n", !!(ret & attr->index));
 295}
 296
 297static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7410_show_temp, NULL, 0);
 298static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 299                          adt7410_show_temp, adt7410_set_temp, 1);
 300static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
 301                          adt7410_show_temp, adt7410_set_temp, 2);
 302static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
 303                          adt7410_show_temp, adt7410_set_temp, 3);
 304static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 305                          adt7410_show_t_hyst, adt7410_set_t_hyst, 1);
 306static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
 307                          adt7410_show_t_hyst, NULL, 2);
 308static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 309                          adt7410_show_t_hyst, NULL, 3);
 310static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7410_show_alarm,
 311                          NULL, ADT7410_STAT_T_LOW);
 312static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7410_show_alarm,
 313                          NULL, ADT7410_STAT_T_HIGH);
 314static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7410_show_alarm,
 315                          NULL, ADT7410_STAT_T_CRIT);
 316
 317static struct attribute *adt7410_attributes[] = {
 318        &sensor_dev_attr_temp1_input.dev_attr.attr,
 319        &sensor_dev_attr_temp1_max.dev_attr.attr,
 320        &sensor_dev_attr_temp1_min.dev_attr.attr,
 321        &sensor_dev_attr_temp1_crit.dev_attr.attr,
 322        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 323        &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
 324        &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 325        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 326        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 327        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 328        NULL
 329};
 330
 331static const struct attribute_group adt7410_group = {
 332        .attrs = adt7410_attributes,
 333};
 334
 335/*-----------------------------------------------------------------------*/
 336
 337/* device probe and removal */
 338
 339static int adt7410_probe(struct i2c_client *client,
 340                         const struct i2c_device_id *id)
 341{
 342        struct adt7410_data *data;
 343        int ret;
 344
 345        if (!i2c_check_functionality(client->adapter,
 346                        I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
 347                return -ENODEV;
 348
 349        data = devm_kzalloc(&client->dev, sizeof(struct adt7410_data),
 350                            GFP_KERNEL);
 351        if (!data)
 352                return -ENOMEM;
 353
 354        i2c_set_clientdata(client, data);
 355        mutex_init(&data->update_lock);
 356
 357        /* configure as specified */
 358        ret = i2c_smbus_read_byte_data(client, ADT7410_CONFIG);
 359        if (ret < 0) {
 360                dev_dbg(&client->dev, "Can't read config? %d\n", ret);
 361                return ret;
 362        }
 363        data->oldconfig = ret;
 364        /*
 365         * Set to 16 bit resolution, continous conversion and comparator mode.
 366         */
 367        data->config = ret | ADT7410_FULL | ADT7410_RESOLUTION |
 368                        ADT7410_EVENT_MODE;
 369        if (data->config != data->oldconfig) {
 370                ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 371                                                data->config);
 372                if (ret)
 373                        return ret;
 374        }
 375        dev_dbg(&client->dev, "Config %02x\n", data->config);
 376
 377        /* Register sysfs hooks */
 378        ret = sysfs_create_group(&client->dev.kobj, &adt7410_group);
 379        if (ret)
 380                goto exit_restore;
 381
 382        data->hwmon_dev = hwmon_device_register(&client->dev);
 383        if (IS_ERR(data->hwmon_dev)) {
 384                ret = PTR_ERR(data->hwmon_dev);
 385                goto exit_remove;
 386        }
 387
 388        dev_info(&client->dev, "sensor '%s'\n", client->name);
 389
 390        return 0;
 391
 392exit_remove:
 393        sysfs_remove_group(&client->dev.kobj, &adt7410_group);
 394exit_restore:
 395        i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->oldconfig);
 396        return ret;
 397}
 398
 399static int adt7410_remove(struct i2c_client *client)
 400{
 401        struct adt7410_data *data = i2c_get_clientdata(client);
 402
 403        hwmon_device_unregister(data->hwmon_dev);
 404        sysfs_remove_group(&client->dev.kobj, &adt7410_group);
 405        if (data->oldconfig != data->config)
 406                i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 407                                          data->oldconfig);
 408        return 0;
 409}
 410
 411static const struct i2c_device_id adt7410_ids[] = {
 412        { "adt7410", adt7410, },
 413        { /* LIST END */ }
 414};
 415MODULE_DEVICE_TABLE(i2c, adt7410_ids);
 416
 417#ifdef CONFIG_PM
 418static int adt7410_suspend(struct device *dev)
 419{
 420        int ret;
 421        struct i2c_client *client = to_i2c_client(dev);
 422        struct adt7410_data *data = i2c_get_clientdata(client);
 423
 424        ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 425                                        data->config | ADT7410_PD);
 426        return ret;
 427}
 428
 429static int adt7410_resume(struct device *dev)
 430{
 431        int ret;
 432        struct i2c_client *client = to_i2c_client(dev);
 433        struct adt7410_data *data = i2c_get_clientdata(client);
 434
 435        ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->config);
 436        return ret;
 437}
 438
 439static const struct dev_pm_ops adt7410_dev_pm_ops = {
 440        .suspend        = adt7410_suspend,
 441        .resume         = adt7410_resume,
 442};
 443#define ADT7410_DEV_PM_OPS (&adt7410_dev_pm_ops)
 444#else
 445#define ADT7410_DEV_PM_OPS NULL
 446#endif /* CONFIG_PM */
 447
 448static struct i2c_driver adt7410_driver = {
 449        .class          = I2C_CLASS_HWMON,
 450        .driver = {
 451                .name   = "adt7410",
 452                .pm     = ADT7410_DEV_PM_OPS,
 453        },
 454        .probe          = adt7410_probe,
 455        .remove         = adt7410_remove,
 456        .id_table       = adt7410_ids,
 457        .address_list   = normal_i2c,
 458};
 459
 460module_i2c_driver(adt7410_driver);
 461
 462MODULE_AUTHOR("Hartmut Knaack");
 463MODULE_DESCRIPTION("ADT7410 driver");
 464MODULE_LICENSE("GPL");
 465
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