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 #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 */
  68 struct 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
  85 static 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
  91 static 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
  97 static 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
 103 static 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
 109 static 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
 116 static 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
 135 static 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
 150 static 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
 179 abort:
 180         mutex_unlock(&data->update_lock);
 181         return ret;
 182 }
 183
 184 static 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
 211 static 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
 217 static 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
 233 static 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
 253 static 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
 276 static 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
 297 static 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
 320 static 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
 334 static 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
 343 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7x10_show_temp, NULL, 0);
 344 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 345                           adt7x10_show_temp, adt7x10_set_temp, 1);
 346 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
 347                           adt7x10_show_temp, adt7x10_set_temp, 2);
 348 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
 349                           adt7x10_show_temp, adt7x10_set_temp, 3);
 350 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 351                           adt7x10_show_t_hyst, adt7x10_set_t_hyst, 1);
 352 static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
 353                           adt7x10_show_t_hyst, NULL, 2);
 354 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 355                           adt7x10_show_t_hyst, NULL, 3);
 356 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7x10_show_alarm,
 357                           NULL, ADT7X10_STAT_T_LOW);
 358 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7x10_show_alarm,
 359                           NULL, ADT7X10_STAT_T_HIGH);
 360 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7x10_show_alarm,
 361                           NULL, ADT7X10_STAT_T_CRIT);
 362 static DEVICE_ATTR(name, S_IRUGO, adt7x10_show_name, NULL);
 363
 364 static 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
 378 static const struct attribute_group adt7x10_group = {
 379         .attrs = adt7x10_attributes,
 380 };
 381
 382 int 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
 457 exit_hwmon_device_unregister:
 458         hwmon_device_unregister(data->hwmon_dev);
 459 exit_remove_name:
 460         if (name)
 461                 device_remove_file(dev, &dev_attr_name);
 462 exit_remove:
 463         sysfs_remove_group(&dev->kobj, &adt7x10_group);
 464 exit_restore:
 465         adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 466         return ret;
 467 }
 468 EXPORT_SYMBOL_GPL(adt7x10_probe);
 469
 470 int 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 }
 485 EXPORT_SYMBOL_GPL(adt7x10_remove);
 486
 487 #ifdef CONFIG_PM_SLEEP
 488
 489 static 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
 497 static 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
 504 SIMPLE_DEV_PM_OPS(adt7x10_dev_pm_ops, adt7x10_suspend, adt7x10_resume);
 505 EXPORT_SYMBOL_GPL(adt7x10_dev_pm_ops);
 506
 507 #endif /* CONFIG_PM_SLEEP */
 508
 509 MODULE_AUTHOR("Hartmut Knaack");
 510 MODULE_DESCRIPTION("ADT7410/ADT7420, ADT7310/ADT7320 common code");
 511 MODULE_LICENSE("GPL");