linux/drivers/hwmon/adt7x10.c
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   1/*
   2 * adt7x10.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/hwmon.h>
  29#include <linux/hwmon-sysfs.h>
  30#include <linux/err.h>
  31#include <linux/mutex.h>
  32#include <linux/delay.h>
  33#include <linux/interrupt.h>
  34
  35#include "adt7x10.h"
  36
  37/*
  38 * ADT7X10 status
  39 */
  40#define ADT7X10_STAT_T_LOW              (1 << 4)
  41#define ADT7X10_STAT_T_HIGH             (1 << 5)
  42#define ADT7X10_STAT_T_CRIT             (1 << 6)
  43#define ADT7X10_STAT_NOT_RDY            (1 << 7)
  44
  45/*
  46 * ADT7X10 config
  47 */
  48#define ADT7X10_FAULT_QUEUE_MASK        (1 << 0 | 1 << 1)
  49#define ADT7X10_CT_POLARITY             (1 << 2)
  50#define ADT7X10_INT_POLARITY            (1 << 3)
  51#define ADT7X10_EVENT_MODE              (1 << 4)
  52#define ADT7X10_MODE_MASK               (1 << 5 | 1 << 6)
  53#define ADT7X10_FULL                    (0 << 5 | 0 << 6)
  54#define ADT7X10_PD                      (1 << 5 | 1 << 6)
  55#define ADT7X10_RESOLUTION              (1 << 7)
  56
  57/*
  58 * ADT7X10 masks
  59 */
  60#define ADT7X10_T13_VALUE_MASK          0xFFF8
  61#define ADT7X10_T_HYST_MASK             0xF
  62
  63/* straight from the datasheet */
  64#define ADT7X10_TEMP_MIN (-55000)
  65#define ADT7X10_TEMP_MAX 150000
  66
  67/* Each client has this additional data */
  68struct adt7x10_data {
  69        const struct adt7x10_ops *ops;
  70        const char              *name;
  71        struct device           *hwmon_dev;
  72        struct mutex            update_lock;
  73        u8                      config;
  74        u8                      oldconfig;
  75        bool                    valid;          /* true if registers valid */
  76        unsigned long           last_updated;   /* In jiffies */
  77        s16                     temp[4];        /* Register values,
  78                                                   0 = input
  79                                                   1 = high
  80                                                   2 = low
  81                                                   3 = critical */
  82        u8                      hyst;           /* hysteresis offset */
  83};
  84
  85static int adt7x10_read_byte(struct device *dev, u8 reg)
  86{
  87        struct adt7x10_data *d = dev_get_drvdata(dev);
  88        return d->ops->read_byte(dev, reg);
  89}
  90
  91static int adt7x10_write_byte(struct device *dev, u8 reg, u8 data)
  92{
  93        struct adt7x10_data *d = dev_get_drvdata(dev);
  94        return d->ops->write_byte(dev, reg, data);
  95}
  96
  97static int adt7x10_read_word(struct device *dev, u8 reg)
  98{
  99        struct adt7x10_data *d = dev_get_drvdata(dev);
 100        return d->ops->read_word(dev, reg);
 101}
 102
 103static int adt7x10_write_word(struct device *dev, u8 reg, u16 data)
 104{
 105        struct adt7x10_data *d = dev_get_drvdata(dev);
 106        return d->ops->write_word(dev, reg, data);
 107}
 108
 109static const u8 ADT7X10_REG_TEMP[4] = {
 110        ADT7X10_TEMPERATURE,            /* input */
 111        ADT7X10_T_ALARM_HIGH,           /* high */
 112        ADT7X10_T_ALARM_LOW,            /* low */
 113        ADT7X10_T_CRIT,                 /* critical */
 114};
 115
 116static irqreturn_t adt7x10_irq_handler(int irq, void *private)
 117{
 118        struct device *dev = private;
 119        int status;
 120
 121        status = adt7x10_read_byte(dev, ADT7X10_STATUS);
 122        if (status < 0)
 123                return IRQ_HANDLED;
 124
 125        if (status & ADT7X10_STAT_T_HIGH)
 126                sysfs_notify(&dev->kobj, NULL, "temp1_max_alarm");
 127        if (status & ADT7X10_STAT_T_LOW)
 128                sysfs_notify(&dev->kobj, NULL, "temp1_min_alarm");
 129        if (status & ADT7X10_STAT_T_CRIT)
 130                sysfs_notify(&dev->kobj, NULL, "temp1_crit_alarm");
 131
 132        return IRQ_HANDLED;
 133}
 134
 135static int adt7x10_temp_ready(struct device *dev)
 136{
 137        int i, status;
 138
 139        for (i = 0; i < 6; i++) {
 140                status = adt7x10_read_byte(dev, ADT7X10_STATUS);
 141                if (status < 0)
 142                        return status;
 143                if (!(status & ADT7X10_STAT_NOT_RDY))
 144                        return 0;
 145                msleep(60);
 146        }
 147        return -ETIMEDOUT;
 148}
 149
 150static int adt7x10_update_temp(struct device *dev)
 151{
 152        struct adt7x10_data *data = dev_get_drvdata(dev);
 153        int ret = 0;
 154
 155        mutex_lock(&data->update_lock);
 156
 157        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 158            || !data->valid) {
 159                int temp;
 160
 161                dev_dbg(dev, "Starting update\n");
 162
 163                ret = adt7x10_temp_ready(dev); /* check for new value */
 164                if (ret)
 165                        goto abort;
 166
 167                temp = adt7x10_read_word(dev, ADT7X10_REG_TEMP[0]);
 168                if (temp < 0) {
 169                        ret = temp;
 170                        dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 171                                ADT7X10_REG_TEMP[0], ret);
 172                        goto abort;
 173                }
 174                data->temp[0] = temp;
 175                data->last_updated = jiffies;
 176                data->valid = true;
 177        }
 178
 179abort:
 180        mutex_unlock(&data->update_lock);
 181        return ret;
 182}
 183
 184static int adt7x10_fill_cache(struct device *dev)
 185{
 186        struct adt7x10_data *data = dev_get_drvdata(dev);
 187        int ret;
 188        int i;
 189
 190        for (i = 1; i < ARRAY_SIZE(data->temp); i++) {
 191                ret = adt7x10_read_word(dev, ADT7X10_REG_TEMP[i]);
 192                if (ret < 0) {
 193                        dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 194                                ADT7X10_REG_TEMP[i], ret);
 195                        return ret;
 196                }
 197                data->temp[i] = ret;
 198        }
 199
 200        ret = adt7x10_read_byte(dev, ADT7X10_T_HYST);
 201        if (ret < 0) {
 202                dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 203                                ADT7X10_T_HYST, ret);
 204                return ret;
 205        }
 206        data->hyst = ret;
 207
 208        return 0;
 209}
 210
 211static s16 ADT7X10_TEMP_TO_REG(long temp)
 212{
 213        return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7X10_TEMP_MIN,
 214                                               ADT7X10_TEMP_MAX) * 128, 1000);
 215}
 216
 217static int ADT7X10_REG_TO_TEMP(struct adt7x10_data *data, s16 reg)
 218{
 219        /* in 13 bit mode, bits 0-2 are status flags - mask them out */
 220        if (!(data->config & ADT7X10_RESOLUTION))
 221                reg &= ADT7X10_T13_VALUE_MASK;
 222        /*
 223         * temperature is stored in twos complement format, in steps of
 224         * 1/128°C
 225         */
 226        return DIV_ROUND_CLOSEST(reg * 1000, 128);
 227}
 228
 229/*-----------------------------------------------------------------------*/
 230
 231/* sysfs attributes for hwmon */
 232
 233static ssize_t adt7x10_show_temp(struct device *dev,
 234                                 struct device_attribute *da,
 235                                 char *buf)
 236{
 237        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 238        struct adt7x10_data *data = dev_get_drvdata(dev);
 239
 240
 241        if (attr->index == 0) {
 242                int ret;
 243
 244                ret = adt7x10_update_temp(dev);
 245                if (ret)
 246                        return ret;
 247        }
 248
 249        return sprintf(buf, "%d\n", ADT7X10_REG_TO_TEMP(data,
 250                       data->temp[attr->index]));
 251}
 252
 253static ssize_t adt7x10_set_temp(struct device *dev,
 254                                struct device_attribute *da,
 255                                const char *buf, size_t count)
 256{
 257        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 258        struct adt7x10_data *data = dev_get_drvdata(dev);
 259        int nr = attr->index;
 260        long temp;
 261        int ret;
 262
 263        ret = kstrtol(buf, 10, &temp);
 264        if (ret)
 265                return ret;
 266
 267        mutex_lock(&data->update_lock);
 268        data->temp[nr] = ADT7X10_TEMP_TO_REG(temp);
 269        ret = adt7x10_write_word(dev, ADT7X10_REG_TEMP[nr], data->temp[nr]);
 270        if (ret)
 271                count = ret;
 272        mutex_unlock(&data->update_lock);
 273        return count;
 274}
 275
 276static ssize_t adt7x10_show_t_hyst(struct device *dev,
 277                                   struct device_attribute *da,
 278                                   char *buf)
 279{
 280        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 281        struct adt7x10_data *data = dev_get_drvdata(dev);
 282        int nr = attr->index;
 283        int hyst;
 284
 285        hyst = (data->hyst & ADT7X10_T_HYST_MASK) * 1000;
 286
 287        /*
 288         * hysteresis is stored as a 4 bit offset in the device, convert it
 289         * to an absolute value
 290         */
 291        if (nr == 2)    /* min has positive offset, others have negative */
 292                hyst = -hyst;
 293        return sprintf(buf, "%d\n",
 294                       ADT7X10_REG_TO_TEMP(data, data->temp[nr]) - hyst);
 295}
 296
 297static ssize_t adt7x10_set_t_hyst(struct device *dev,
 298                                  struct device_attribute *da,
 299                                  const char *buf, size_t count)
 300{
 301        struct adt7x10_data *data = dev_get_drvdata(dev);
 302        int limit, ret;
 303        long hyst;
 304
 305        ret = kstrtol(buf, 10, &hyst);
 306        if (ret)
 307                return ret;
 308        /* convert absolute hysteresis value to a 4 bit delta value */
 309        limit = ADT7X10_REG_TO_TEMP(data, data->temp[1]);
 310        hyst = clamp_val(hyst, ADT7X10_TEMP_MIN, ADT7X10_TEMP_MAX);
 311        data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000),
 312                                   0, ADT7X10_T_HYST_MASK);
 313        ret = adt7x10_write_byte(dev, ADT7X10_T_HYST, data->hyst);
 314        if (ret)
 315                return ret;
 316
 317        return count;
 318}
 319
 320static ssize_t adt7x10_show_alarm(struct device *dev,
 321                                  struct device_attribute *da,
 322                                  char *buf)
 323{
 324        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 325        int ret;
 326
 327        ret = adt7x10_read_byte(dev, ADT7X10_STATUS);
 328        if (ret < 0)
 329                return ret;
 330
 331        return sprintf(buf, "%d\n", !!(ret & attr->index));
 332}
 333
 334static ssize_t adt7x10_show_name(struct device *dev,
 335                                 struct device_attribute *da,
 336                                 char *buf)
 337{
 338        struct adt7x10_data *data = dev_get_drvdata(dev);
 339
 340        return sprintf(buf, "%s\n", data->name);
 341}
 342
 343static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7x10_show_temp, NULL, 0);
 344static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 345                          adt7x10_show_temp, adt7x10_set_temp, 1);
 346static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
 347                          adt7x10_show_temp, adt7x10_set_temp, 2);
 348static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
 349                          adt7x10_show_temp, adt7x10_set_temp, 3);
 350static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 351                          adt7x10_show_t_hyst, adt7x10_set_t_hyst, 1);
 352static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
 353                          adt7x10_show_t_hyst, NULL, 2);
 354static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 355                          adt7x10_show_t_hyst, NULL, 3);
 356static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7x10_show_alarm,
 357                          NULL, ADT7X10_STAT_T_LOW);
 358static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7x10_show_alarm,
 359                          NULL, ADT7X10_STAT_T_HIGH);
 360static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7x10_show_alarm,
 361                          NULL, ADT7X10_STAT_T_CRIT);
 362static DEVICE_ATTR(name, S_IRUGO, adt7x10_show_name, NULL);
 363
 364static struct attribute *adt7x10_attributes[] = {
 365        &sensor_dev_attr_temp1_input.dev_attr.attr,
 366        &sensor_dev_attr_temp1_max.dev_attr.attr,
 367        &sensor_dev_attr_temp1_min.dev_attr.attr,
 368        &sensor_dev_attr_temp1_crit.dev_attr.attr,
 369        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 370        &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
 371        &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 372        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 373        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 374        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 375        NULL
 376};
 377
 378static const struct attribute_group adt7x10_group = {
 379        .attrs = adt7x10_attributes,
 380};
 381
 382int adt7x10_probe(struct device *dev, const char *name, int irq,
 383                  const struct adt7x10_ops *ops)
 384{
 385        struct adt7x10_data *data;
 386        int ret;
 387
 388        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 389        if (!data)
 390                return -ENOMEM;
 391
 392        data->ops = ops;
 393        data->name = name;
 394
 395        dev_set_drvdata(dev, data);
 396        mutex_init(&data->update_lock);
 397
 398        /* configure as specified */
 399        ret = adt7x10_read_byte(dev, ADT7X10_CONFIG);
 400        if (ret < 0) {
 401                dev_dbg(dev, "Can't read config? %d\n", ret);
 402                return ret;
 403        }
 404        data->oldconfig = ret;
 405
 406        /*
 407         * Set to 16 bit resolution, continous conversion and comparator mode.
 408         */
 409        data->config = data->oldconfig;
 410        data->config &= ~(ADT7X10_MODE_MASK | ADT7X10_CT_POLARITY |
 411                        ADT7X10_INT_POLARITY);
 412        data->config |= ADT7X10_FULL | ADT7X10_RESOLUTION | ADT7X10_EVENT_MODE;
 413
 414        if (data->config != data->oldconfig) {
 415                ret = adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
 416                if (ret)
 417                        return ret;
 418        }
 419        dev_dbg(dev, "Config %02x\n", data->config);
 420
 421        ret = adt7x10_fill_cache(dev);
 422        if (ret)
 423                goto exit_restore;
 424
 425        /* Register sysfs hooks */
 426        ret = sysfs_create_group(&dev->kobj, &adt7x10_group);
 427        if (ret)
 428                goto exit_restore;
 429
 430        /*
 431         * The I2C device will already have it's own 'name' attribute, but for
 432         * the SPI device we need to register it. name will only be non NULL if
 433         * the device doesn't register the 'name' attribute on its own.
 434         */
 435        if (name) {
 436                ret = device_create_file(dev, &dev_attr_name);
 437                if (ret)
 438                        goto exit_remove;
 439        }
 440
 441        data->hwmon_dev = hwmon_device_register(dev);
 442        if (IS_ERR(data->hwmon_dev)) {
 443                ret = PTR_ERR(data->hwmon_dev);
 444                goto exit_remove_name;
 445        }
 446
 447        if (irq > 0) {
 448                ret = request_threaded_irq(irq, NULL, adt7x10_irq_handler,
 449                                IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 450                                dev_name(dev), dev);
 451                if (ret)
 452                        goto exit_hwmon_device_unregister;
 453        }
 454
 455        return 0;
 456
 457exit_hwmon_device_unregister:
 458        hwmon_device_unregister(data->hwmon_dev);
 459exit_remove_name:
 460        if (name)
 461                device_remove_file(dev, &dev_attr_name);
 462exit_remove:
 463        sysfs_remove_group(&dev->kobj, &adt7x10_group);
 464exit_restore:
 465        adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 466        return ret;
 467}
 468EXPORT_SYMBOL_GPL(adt7x10_probe);
 469
 470int adt7x10_remove(struct device *dev, int irq)
 471{
 472        struct adt7x10_data *data = dev_get_drvdata(dev);
 473
 474        if (irq > 0)
 475                free_irq(irq, dev);
 476
 477        hwmon_device_unregister(data->hwmon_dev);
 478        if (data->name)
 479                device_remove_file(dev, &dev_attr_name);
 480        sysfs_remove_group(&dev->kobj, &adt7x10_group);
 481        if (data->oldconfig != data->config)
 482                adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 483        return 0;
 484}
 485EXPORT_SYMBOL_GPL(adt7x10_remove);
 486
 487#ifdef CONFIG_PM_SLEEP
 488
 489static int adt7x10_suspend(struct device *dev)
 490{
 491        struct adt7x10_data *data = dev_get_drvdata(dev);
 492
 493        return adt7x10_write_byte(dev, ADT7X10_CONFIG,
 494                data->config | ADT7X10_PD);
 495}
 496
 497static int adt7x10_resume(struct device *dev)
 498{
 499        struct adt7x10_data *data = dev_get_drvdata(dev);
 500
 501        return adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
 502}
 503
 504SIMPLE_DEV_PM_OPS(adt7x10_dev_pm_ops, adt7x10_suspend, adt7x10_resume);
 505EXPORT_SYMBOL_GPL(adt7x10_dev_pm_ops);
 506
 507#endif /* CONFIG_PM_SLEEP */
 508
 509MODULE_AUTHOR("Hartmut Knaack");
 510MODULE_DESCRIPTION("ADT7410/ADT7420, ADT7310/ADT7320 common code");
 511MODULE_LICENSE("GPL");
 512
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