linux/drivers/hwmon/adt7x10.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * adt7x10.c - Part of lm_sensors, Linux kernel modules for hardware
   4 *       monitoring
   5 * This driver handles the ADT7410 and compatible digital temperature sensors.
   6 * Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
   7 * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
   8 * and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>
   9 */
  10
  11#include <linux/module.h>
  12#include <linux/init.h>
  13#include <linux/slab.h>
  14#include <linux/jiffies.h>
  15#include <linux/hwmon.h>
  16#include <linux/hwmon-sysfs.h>
  17#include <linux/err.h>
  18#include <linux/mutex.h>
  19#include <linux/delay.h>
  20#include <linux/interrupt.h>
  21
  22#include "adt7x10.h"
  23
  24/*
  25 * ADT7X10 status
  26 */
  27#define ADT7X10_STAT_T_LOW              (1 << 4)
  28#define ADT7X10_STAT_T_HIGH             (1 << 5)
  29#define ADT7X10_STAT_T_CRIT             (1 << 6)
  30#define ADT7X10_STAT_NOT_RDY            (1 << 7)
  31
  32/*
  33 * ADT7X10 config
  34 */
  35#define ADT7X10_FAULT_QUEUE_MASK        (1 << 0 | 1 << 1)
  36#define ADT7X10_CT_POLARITY             (1 << 2)
  37#define ADT7X10_INT_POLARITY            (1 << 3)
  38#define ADT7X10_EVENT_MODE              (1 << 4)
  39#define ADT7X10_MODE_MASK               (1 << 5 | 1 << 6)
  40#define ADT7X10_FULL                    (0 << 5 | 0 << 6)
  41#define ADT7X10_PD                      (1 << 5 | 1 << 6)
  42#define ADT7X10_RESOLUTION              (1 << 7)
  43
  44/*
  45 * ADT7X10 masks
  46 */
  47#define ADT7X10_T13_VALUE_MASK          0xFFF8
  48#define ADT7X10_T_HYST_MASK             0xF
  49
  50/* straight from the datasheet */
  51#define ADT7X10_TEMP_MIN (-55000)
  52#define ADT7X10_TEMP_MAX 150000
  53
  54/* Each client has this additional data */
  55struct adt7x10_data {
  56        const struct adt7x10_ops *ops;
  57        const char              *name;
  58        struct device           *hwmon_dev;
  59        struct mutex            update_lock;
  60        u8                      config;
  61        u8                      oldconfig;
  62        bool                    valid;          /* true if registers valid */
  63        unsigned long           last_updated;   /* In jiffies */
  64        s16                     temp[4];        /* Register values,
  65                                                   0 = input
  66                                                   1 = high
  67                                                   2 = low
  68                                                   3 = critical */
  69        u8                      hyst;           /* hysteresis offset */
  70};
  71
  72static int adt7x10_read_byte(struct device *dev, u8 reg)
  73{
  74        struct adt7x10_data *d = dev_get_drvdata(dev);
  75        return d->ops->read_byte(dev, reg);
  76}
  77
  78static int adt7x10_write_byte(struct device *dev, u8 reg, u8 data)
  79{
  80        struct adt7x10_data *d = dev_get_drvdata(dev);
  81        return d->ops->write_byte(dev, reg, data);
  82}
  83
  84static int adt7x10_read_word(struct device *dev, u8 reg)
  85{
  86        struct adt7x10_data *d = dev_get_drvdata(dev);
  87        return d->ops->read_word(dev, reg);
  88}
  89
  90static int adt7x10_write_word(struct device *dev, u8 reg, u16 data)
  91{
  92        struct adt7x10_data *d = dev_get_drvdata(dev);
  93        return d->ops->write_word(dev, reg, data);
  94}
  95
  96static const u8 ADT7X10_REG_TEMP[4] = {
  97        ADT7X10_TEMPERATURE,            /* input */
  98        ADT7X10_T_ALARM_HIGH,           /* high */
  99        ADT7X10_T_ALARM_LOW,            /* low */
 100        ADT7X10_T_CRIT,                 /* critical */
 101};
 102
 103static irqreturn_t adt7x10_irq_handler(int irq, void *private)
 104{
 105        struct device *dev = private;
 106        int status;
 107
 108        status = adt7x10_read_byte(dev, ADT7X10_STATUS);
 109        if (status < 0)
 110                return IRQ_HANDLED;
 111
 112        if (status & ADT7X10_STAT_T_HIGH)
 113                sysfs_notify(&dev->kobj, NULL, "temp1_max_alarm");
 114        if (status & ADT7X10_STAT_T_LOW)
 115                sysfs_notify(&dev->kobj, NULL, "temp1_min_alarm");
 116        if (status & ADT7X10_STAT_T_CRIT)
 117                sysfs_notify(&dev->kobj, NULL, "temp1_crit_alarm");
 118
 119        return IRQ_HANDLED;
 120}
 121
 122static int adt7x10_temp_ready(struct device *dev)
 123{
 124        int i, status;
 125
 126        for (i = 0; i < 6; i++) {
 127                status = adt7x10_read_byte(dev, ADT7X10_STATUS);
 128                if (status < 0)
 129                        return status;
 130                if (!(status & ADT7X10_STAT_NOT_RDY))
 131                        return 0;
 132                msleep(60);
 133        }
 134        return -ETIMEDOUT;
 135}
 136
 137static int adt7x10_update_temp(struct device *dev)
 138{
 139        struct adt7x10_data *data = dev_get_drvdata(dev);
 140        int ret = 0;
 141
 142        mutex_lock(&data->update_lock);
 143
 144        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 145            || !data->valid) {
 146                int temp;
 147
 148                dev_dbg(dev, "Starting update\n");
 149
 150                ret = adt7x10_temp_ready(dev); /* check for new value */
 151                if (ret)
 152                        goto abort;
 153
 154                temp = adt7x10_read_word(dev, ADT7X10_REG_TEMP[0]);
 155                if (temp < 0) {
 156                        ret = temp;
 157                        dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 158                                ADT7X10_REG_TEMP[0], ret);
 159                        goto abort;
 160                }
 161                data->temp[0] = temp;
 162                data->last_updated = jiffies;
 163                data->valid = true;
 164        }
 165
 166abort:
 167        mutex_unlock(&data->update_lock);
 168        return ret;
 169}
 170
 171static int adt7x10_fill_cache(struct device *dev)
 172{
 173        struct adt7x10_data *data = dev_get_drvdata(dev);
 174        int ret;
 175        int i;
 176
 177        for (i = 1; i < ARRAY_SIZE(data->temp); i++) {
 178                ret = adt7x10_read_word(dev, ADT7X10_REG_TEMP[i]);
 179                if (ret < 0) {
 180                        dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 181                                ADT7X10_REG_TEMP[i], ret);
 182                        return ret;
 183                }
 184                data->temp[i] = ret;
 185        }
 186
 187        ret = adt7x10_read_byte(dev, ADT7X10_T_HYST);
 188        if (ret < 0) {
 189                dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 190                                ADT7X10_T_HYST, ret);
 191                return ret;
 192        }
 193        data->hyst = ret;
 194
 195        return 0;
 196}
 197
 198static s16 ADT7X10_TEMP_TO_REG(long temp)
 199{
 200        return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7X10_TEMP_MIN,
 201                                               ADT7X10_TEMP_MAX) * 128, 1000);
 202}
 203
 204static int ADT7X10_REG_TO_TEMP(struct adt7x10_data *data, s16 reg)
 205{
 206        /* in 13 bit mode, bits 0-2 are status flags - mask them out */
 207        if (!(data->config & ADT7X10_RESOLUTION))
 208                reg &= ADT7X10_T13_VALUE_MASK;
 209        /*
 210         * temperature is stored in twos complement format, in steps of
 211         * 1/128°C
 212         */
 213        return DIV_ROUND_CLOSEST(reg * 1000, 128);
 214}
 215
 216/*-----------------------------------------------------------------------*/
 217
 218/* sysfs attributes for hwmon */
 219
 220static ssize_t adt7x10_temp_show(struct device *dev,
 221                                 struct device_attribute *da, char *buf)
 222{
 223        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 224        struct adt7x10_data *data = dev_get_drvdata(dev);
 225
 226
 227        if (attr->index == 0) {
 228                int ret;
 229
 230                ret = adt7x10_update_temp(dev);
 231                if (ret)
 232                        return ret;
 233        }
 234
 235        return sprintf(buf, "%d\n", ADT7X10_REG_TO_TEMP(data,
 236                       data->temp[attr->index]));
 237}
 238
 239static ssize_t adt7x10_temp_store(struct device *dev,
 240                                  struct device_attribute *da,
 241                                  const char *buf, size_t count)
 242{
 243        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 244        struct adt7x10_data *data = dev_get_drvdata(dev);
 245        int nr = attr->index;
 246        long temp;
 247        int ret;
 248
 249        ret = kstrtol(buf, 10, &temp);
 250        if (ret)
 251                return ret;
 252
 253        mutex_lock(&data->update_lock);
 254        data->temp[nr] = ADT7X10_TEMP_TO_REG(temp);
 255        ret = adt7x10_write_word(dev, ADT7X10_REG_TEMP[nr], data->temp[nr]);
 256        if (ret)
 257                count = ret;
 258        mutex_unlock(&data->update_lock);
 259        return count;
 260}
 261
 262static ssize_t adt7x10_t_hyst_show(struct device *dev,
 263                                   struct device_attribute *da, char *buf)
 264{
 265        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 266        struct adt7x10_data *data = dev_get_drvdata(dev);
 267        int nr = attr->index;
 268        int hyst;
 269
 270        hyst = (data->hyst & ADT7X10_T_HYST_MASK) * 1000;
 271
 272        /*
 273         * hysteresis is stored as a 4 bit offset in the device, convert it
 274         * to an absolute value
 275         */
 276        if (nr == 2)    /* min has positive offset, others have negative */
 277                hyst = -hyst;
 278        return sprintf(buf, "%d\n",
 279                       ADT7X10_REG_TO_TEMP(data, data->temp[nr]) - hyst);
 280}
 281
 282static ssize_t adt7x10_t_hyst_store(struct device *dev,
 283                                    struct device_attribute *da,
 284                                    const char *buf, size_t count)
 285{
 286        struct adt7x10_data *data = dev_get_drvdata(dev);
 287        int limit, ret;
 288        long hyst;
 289
 290        ret = kstrtol(buf, 10, &hyst);
 291        if (ret)
 292                return ret;
 293        /* convert absolute hysteresis value to a 4 bit delta value */
 294        limit = ADT7X10_REG_TO_TEMP(data, data->temp[1]);
 295        hyst = clamp_val(hyst, ADT7X10_TEMP_MIN, ADT7X10_TEMP_MAX);
 296        data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000),
 297                                   0, ADT7X10_T_HYST_MASK);
 298        ret = adt7x10_write_byte(dev, ADT7X10_T_HYST, data->hyst);
 299        if (ret)
 300                return ret;
 301
 302        return count;
 303}
 304
 305static ssize_t adt7x10_alarm_show(struct device *dev,
 306                                  struct device_attribute *da, char *buf)
 307{
 308        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 309        int ret;
 310
 311        ret = adt7x10_read_byte(dev, ADT7X10_STATUS);
 312        if (ret < 0)
 313                return ret;
 314
 315        return sprintf(buf, "%d\n", !!(ret & attr->index));
 316}
 317
 318static ssize_t name_show(struct device *dev, struct device_attribute *da,
 319                         char *buf)
 320{
 321        struct adt7x10_data *data = dev_get_drvdata(dev);
 322
 323        return sprintf(buf, "%s\n", data->name);
 324}
 325
 326static SENSOR_DEVICE_ATTR_RO(temp1_input, adt7x10_temp, 0);
 327static SENSOR_DEVICE_ATTR_RW(temp1_max, adt7x10_temp, 1);
 328static SENSOR_DEVICE_ATTR_RW(temp1_min, adt7x10_temp, 2);
 329static SENSOR_DEVICE_ATTR_RW(temp1_crit, adt7x10_temp, 3);
 330static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, adt7x10_t_hyst, 1);
 331static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, adt7x10_t_hyst, 2);
 332static SENSOR_DEVICE_ATTR_RO(temp1_crit_hyst, adt7x10_t_hyst, 3);
 333static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, adt7x10_alarm,
 334                             ADT7X10_STAT_T_LOW);
 335static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adt7x10_alarm,
 336                             ADT7X10_STAT_T_HIGH);
 337static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, adt7x10_alarm,
 338                             ADT7X10_STAT_T_CRIT);
 339static DEVICE_ATTR_RO(name);
 340
 341static struct attribute *adt7x10_attributes[] = {
 342        &sensor_dev_attr_temp1_input.dev_attr.attr,
 343        &sensor_dev_attr_temp1_max.dev_attr.attr,
 344        &sensor_dev_attr_temp1_min.dev_attr.attr,
 345        &sensor_dev_attr_temp1_crit.dev_attr.attr,
 346        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 347        &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
 348        &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 349        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 350        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 351        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 352        NULL
 353};
 354
 355static const struct attribute_group adt7x10_group = {
 356        .attrs = adt7x10_attributes,
 357};
 358
 359int adt7x10_probe(struct device *dev, const char *name, int irq,
 360                  const struct adt7x10_ops *ops)
 361{
 362        struct adt7x10_data *data;
 363        int ret;
 364
 365        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 366        if (!data)
 367                return -ENOMEM;
 368
 369        data->ops = ops;
 370        data->name = name;
 371
 372        dev_set_drvdata(dev, data);
 373        mutex_init(&data->update_lock);
 374
 375        /* configure as specified */
 376        ret = adt7x10_read_byte(dev, ADT7X10_CONFIG);
 377        if (ret < 0) {
 378                dev_dbg(dev, "Can't read config? %d\n", ret);
 379                return ret;
 380        }
 381        data->oldconfig = ret;
 382
 383        /*
 384         * Set to 16 bit resolution, continous conversion and comparator mode.
 385         */
 386        data->config = data->oldconfig;
 387        data->config &= ~(ADT7X10_MODE_MASK | ADT7X10_CT_POLARITY |
 388                        ADT7X10_INT_POLARITY);
 389        data->config |= ADT7X10_FULL | ADT7X10_RESOLUTION | ADT7X10_EVENT_MODE;
 390
 391        if (data->config != data->oldconfig) {
 392                ret = adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
 393                if (ret)
 394                        return ret;
 395        }
 396        dev_dbg(dev, "Config %02x\n", data->config);
 397
 398        ret = adt7x10_fill_cache(dev);
 399        if (ret)
 400                goto exit_restore;
 401
 402        /* Register sysfs hooks */
 403        ret = sysfs_create_group(&dev->kobj, &adt7x10_group);
 404        if (ret)
 405                goto exit_restore;
 406
 407        /*
 408         * The I2C device will already have it's own 'name' attribute, but for
 409         * the SPI device we need to register it. name will only be non NULL if
 410         * the device doesn't register the 'name' attribute on its own.
 411         */
 412        if (name) {
 413                ret = device_create_file(dev, &dev_attr_name);
 414                if (ret)
 415                        goto exit_remove;
 416        }
 417
 418        data->hwmon_dev = hwmon_device_register(dev);
 419        if (IS_ERR(data->hwmon_dev)) {
 420                ret = PTR_ERR(data->hwmon_dev);
 421                goto exit_remove_name;
 422        }
 423
 424        if (irq > 0) {
 425                ret = request_threaded_irq(irq, NULL, adt7x10_irq_handler,
 426                                IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 427                                dev_name(dev), dev);
 428                if (ret)
 429                        goto exit_hwmon_device_unregister;
 430        }
 431
 432        return 0;
 433
 434exit_hwmon_device_unregister:
 435        hwmon_device_unregister(data->hwmon_dev);
 436exit_remove_name:
 437        if (name)
 438                device_remove_file(dev, &dev_attr_name);
 439exit_remove:
 440        sysfs_remove_group(&dev->kobj, &adt7x10_group);
 441exit_restore:
 442        adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 443        return ret;
 444}
 445EXPORT_SYMBOL_GPL(adt7x10_probe);
 446
 447int adt7x10_remove(struct device *dev, int irq)
 448{
 449        struct adt7x10_data *data = dev_get_drvdata(dev);
 450
 451        if (irq > 0)
 452                free_irq(irq, dev);
 453
 454        hwmon_device_unregister(data->hwmon_dev);
 455        if (data->name)
 456                device_remove_file(dev, &dev_attr_name);
 457        sysfs_remove_group(&dev->kobj, &adt7x10_group);
 458        if (data->oldconfig != data->config)
 459                adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 460        return 0;
 461}
 462EXPORT_SYMBOL_GPL(adt7x10_remove);
 463
 464#ifdef CONFIG_PM_SLEEP
 465
 466static int adt7x10_suspend(struct device *dev)
 467{
 468        struct adt7x10_data *data = dev_get_drvdata(dev);
 469
 470        return adt7x10_write_byte(dev, ADT7X10_CONFIG,
 471                data->config | ADT7X10_PD);
 472}
 473
 474static int adt7x10_resume(struct device *dev)
 475{
 476        struct adt7x10_data *data = dev_get_drvdata(dev);
 477
 478        return adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
 479}
 480
 481SIMPLE_DEV_PM_OPS(adt7x10_dev_pm_ops, adt7x10_suspend, adt7x10_resume);
 482EXPORT_SYMBOL_GPL(adt7x10_dev_pm_ops);
 483
 484#endif /* CONFIG_PM_SLEEP */
 485
 486MODULE_AUTHOR("Hartmut Knaack");
 487MODULE_DESCRIPTION("ADT7410/ADT7420, ADT7310/ADT7320 common code");
 488MODULE_LICENSE("GPL");
 489