drivers/hwmon/adt7x10.c

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