drivers/hwmon/adc128d818.c

   1 /*
   2  * Driver for TI ADC128D818 System Monitor with Temperature Sensor
   3  *
   4  * Copyright (c) 2014 Guenter Roeck
   5  *
   6  * Derived from lm80.c
   7  * Copyright (C) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
   8  *                           and Philip Edelbrock <phil@netroedge.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/slab.h>
  23 #include <linux/jiffies.h>
  24 #include <linux/i2c.h>
  25 #include <linux/hwmon.h>
  26 #include <linux/hwmon-sysfs.h>
  27 #include <linux/err.h>
  28 #include <linux/regulator/consumer.h>
  29 #include <linux/mutex.h>
  30 #include <linux/bitops.h>
  31 #include <linux/of.h>
  32
  33 /* Addresses to scan
  34  * The chip also supports addresses 0x35..0x37. Don't scan those addresses
  35  * since they are also used by some EEPROMs, which may result in false
  36  * positives.
  37  */
  38 static const unsigned short normal_i2c[] = {
  39         0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f, I2C_CLIENT_END };
  40
  41 /* registers */
  42 #define ADC128_REG_IN_MAX(nr)           (0x2a + (nr) * 2)
  43 #define ADC128_REG_IN_MIN(nr)           (0x2b + (nr) * 2)
  44 #define ADC128_REG_IN(nr)               (0x20 + (nr))
  45
  46 #define ADC128_REG_TEMP                 0x27
  47 #define ADC128_REG_TEMP_MAX             0x38
  48 #define ADC128_REG_TEMP_HYST            0x39
  49
  50 #define ADC128_REG_CONFIG               0x00
  51 #define ADC128_REG_ALARM                0x01
  52 #define ADC128_REG_MASK                 0x03
  53 #define ADC128_REG_CONV_RATE            0x07
  54 #define ADC128_REG_ONESHOT              0x09
  55 #define ADC128_REG_SHUTDOWN             0x0a
  56 #define ADC128_REG_CONFIG_ADV           0x0b
  57 #define ADC128_REG_BUSY_STATUS          0x0c
  58
  59 #define ADC128_REG_MAN_ID               0x3e
  60 #define ADC128_REG_DEV_ID               0x3f
  61
  62 /* No. of voltage entries in adc128_attrs */
  63 #define ADC128_ATTR_NUM_VOLT            (8 * 4)
  64
  65 /* Voltage inputs visible per operation mode */
  66 static const u8 num_inputs[] = { 7, 8, 4, 6 };
  67
  68 struct adc128_data {
  69         struct i2c_client *client;
  70         struct regulator *regulator;
  71         int vref;               /* Reference voltage in mV */
  72         struct mutex update_lock;
  73         u8 mode;                /* Operation mode */
  74         bool valid;             /* true if following fields are valid */
  75         unsigned long last_updated;     /* In jiffies */
  76
  77         u16 in[3][8];           /* Register value, normalized to 12 bit
  78                                  * 0: input voltage
  79                                  * 1: min limit
  80                                  * 2: max limit
  81                                  */
  82         s16 temp[3];            /* Register value, normalized to 9 bit
  83                                  * 0: sensor 1: limit 2: hyst
  84                                  */
  85         u8 alarms;              /* alarm register value */
  86 };
  87
  88 static struct adc128_data *adc128_update_device(struct device *dev)
  89 {
  90         struct adc128_data *data = dev_get_drvdata(dev);
  91         struct i2c_client *client = data->client;
  92         struct adc128_data *ret = data;
  93         int i, rv;
  94
  95         mutex_lock(&data->update_lock);
  96
  97         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  98                 for (i = 0; i < num_inputs[data->mode]; i++) {
  99                         rv = i2c_smbus_read_word_swapped(client,
 100                                                          ADC128_REG_IN(i));
 101                         if (rv < 0)
 102                                 goto abort;
 103                         data->in[0][i] = rv >> 4;
 104
 105                         rv = i2c_smbus_read_byte_data(client,
 106                                                       ADC128_REG_IN_MIN(i));
 107                         if (rv < 0)
 108                                 goto abort;
 109                         data->in[1][i] = rv << 4;
 110
 111                         rv = i2c_smbus_read_byte_data(client,
 112                                                       ADC128_REG_IN_MAX(i));
 113                         if (rv < 0)
 114                                 goto abort;
 115                         data->in[2][i] = rv << 4;
 116                 }
 117
 118                 if (data->mode != 1) {
 119                         rv = i2c_smbus_read_word_swapped(client,
 120                                                          ADC128_REG_TEMP);
 121                         if (rv < 0)
 122                                 goto abort;
 123                         data->temp[0] = rv >> 7;
 124
 125                         rv = i2c_smbus_read_byte_data(client,
 126                                                       ADC128_REG_TEMP_MAX);
 127                         if (rv < 0)
 128                                 goto abort;
 129                         data->temp[1] = rv << 1;
 130
 131                         rv = i2c_smbus_read_byte_data(client,
 132                                                       ADC128_REG_TEMP_HYST);
 133                         if (rv < 0)
 134                                 goto abort;
 135                         data->temp[2] = rv << 1;
 136                 }
 137
 138                 rv = i2c_smbus_read_byte_data(client, ADC128_REG_ALARM);
 139                 if (rv < 0)
 140                         goto abort;
 141                 data->alarms |= rv;
 142
 143                 data->last_updated = jiffies;
 144                 data->valid = true;
 145         }
 146         goto done;
 147
 148 abort:
 149         ret = ERR_PTR(rv);
 150         data->valid = false;
 151 done:
 152         mutex_unlock(&data->update_lock);
 153         return ret;
 154 }
 155
 156 static ssize_t adc128_in_show(struct device *dev,
 157                               struct device_attribute *attr, char *buf)
 158 {
 159         struct adc128_data *data = adc128_update_device(dev);
 160         int index = to_sensor_dev_attr_2(attr)->index;
 161         int nr = to_sensor_dev_attr_2(attr)->nr;
 162         int val;
 163
 164         if (IS_ERR(data))
 165                 return PTR_ERR(data);
 166
 167         val = DIV_ROUND_CLOSEST(data->in[index][nr] * data->vref, 4095);
 168         return sprintf(buf, "%d\n", val);
 169 }
 170
 171 static ssize_t adc128_in_store(struct device *dev,
 172                                struct device_attribute *attr, const char *buf,
 173                                size_t count)
 174 {
 175         struct adc128_data *data = dev_get_drvdata(dev);
 176         int index = to_sensor_dev_attr_2(attr)->index;
 177         int nr = to_sensor_dev_attr_2(attr)->nr;
 178         u8 reg, regval;
 179         long val;
 180         int err;
 181
 182         err = kstrtol(buf, 10, &val);
 183         if (err < 0)
 184                 return err;
 185
 186         mutex_lock(&data->update_lock);
 187         /* 10 mV LSB on limit registers */
 188         regval = clamp_val(DIV_ROUND_CLOSEST(val, 10), 0, 255);
 189         data->in[index][nr] = regval << 4;
 190         reg = index == 1 ? ADC128_REG_IN_MIN(nr) : ADC128_REG_IN_MAX(nr);
 191         i2c_smbus_write_byte_data(data->client, reg, regval);
 192         mutex_unlock(&data->update_lock);
 193
 194         return count;
 195 }
 196
 197 static ssize_t adc128_temp_show(struct device *dev,
 198                                 struct device_attribute *attr, char *buf)
 199 {
 200         struct adc128_data *data = adc128_update_device(dev);
 201         int index = to_sensor_dev_attr(attr)->index;
 202         int temp;
 203
 204         if (IS_ERR(data))
 205                 return PTR_ERR(data);
 206
 207         temp = sign_extend32(data->temp[index], 8);
 208         return sprintf(buf, "%d\n", temp * 500);/* 0.5 degrees C resolution */
 209 }
 210
 211 static ssize_t adc128_temp_store(struct device *dev,
 212                                  struct device_attribute *attr,
 213                                  const char *buf, size_t count)
 214 {
 215         struct adc128_data *data = dev_get_drvdata(dev);
 216         int index = to_sensor_dev_attr(attr)->index;
 217         long val;
 218         int err;
 219         s8 regval;
 220
 221         err = kstrtol(buf, 10, &val);
 222         if (err < 0)
 223                 return err;
 224
 225         mutex_lock(&data->update_lock);
 226         regval = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -128, 127);
 227         data->temp[index] = regval << 1;
 228         i2c_smbus_write_byte_data(data->client,
 229                                   index == 1 ? ADC128_REG_TEMP_MAX
 230                                              : ADC128_REG_TEMP_HYST,
 231                                   regval);
 232         mutex_unlock(&data->update_lock);
 233
 234         return count;
 235 }
 236
 237 static ssize_t adc128_alarm_show(struct device *dev,
 238                                  struct device_attribute *attr, char *buf)
 239 {
 240         struct adc128_data *data = adc128_update_device(dev);
 241         int mask = 1 << to_sensor_dev_attr(attr)->index;
 242         u8 alarms;
 243
 244         if (IS_ERR(data))
 245                 return PTR_ERR(data);
 246
 247         /*
 248          * Clear an alarm after reporting it to user space. If it is still
 249          * active, the next update sequence will set the alarm bit again.
 250          */
 251         alarms = data->alarms;
 252         data->alarms &= ~mask;
 253
 254         return sprintf(buf, "%u\n", !!(alarms & mask));
 255 }
 256
 257 static umode_t adc128_is_visible(struct kobject *kobj,
 258                                  struct attribute *attr, int index)
 259 {
 260         struct device *dev = container_of(kobj, struct device, kobj);
 261         struct adc128_data *data = dev_get_drvdata(dev);
 262
 263         if (index < ADC128_ATTR_NUM_VOLT) {
 264                 /* Voltage, visible according to num_inputs[] */
 265                 if (index >= num_inputs[data->mode] * 4)
 266                         return 0;
 267         } else {
 268                 /* Temperature, visible if not in mode 1 */
 269                 if (data->mode == 1)
 270                         return 0;
 271         }
 272
 273         return attr->mode;
 274 }
 275
 276 static SENSOR_DEVICE_ATTR_2_RO(in0_input, adc128_in, 0, 0);
 277 static SENSOR_DEVICE_ATTR_2_RW(in0_min, adc128_in, 0, 1);
 278 static SENSOR_DEVICE_ATTR_2_RW(in0_max, adc128_in, 0, 2);
 279
 280 static SENSOR_DEVICE_ATTR_2_RO(in1_input, adc128_in, 1, 0);
 281 static SENSOR_DEVICE_ATTR_2_RW(in1_min, adc128_in, 1, 1);
 282 static SENSOR_DEVICE_ATTR_2_RW(in1_max, adc128_in, 1, 2);
 283
 284 static SENSOR_DEVICE_ATTR_2_RO(in2_input, adc128_in, 2, 0);
 285 static SENSOR_DEVICE_ATTR_2_RW(in2_min, adc128_in, 2, 1);
 286 static SENSOR_DEVICE_ATTR_2_RW(in2_max, adc128_in, 2, 2);
 287
 288 static SENSOR_DEVICE_ATTR_2_RO(in3_input, adc128_in, 3, 0);
 289 static SENSOR_DEVICE_ATTR_2_RW(in3_min, adc128_in, 3, 1);
 290 static SENSOR_DEVICE_ATTR_2_RW(in3_max, adc128_in, 3, 2);
 291
 292 static SENSOR_DEVICE_ATTR_2_RO(in4_input, adc128_in, 4, 0);
 293 static SENSOR_DEVICE_ATTR_2_RW(in4_min, adc128_in, 4, 1);
 294 static SENSOR_DEVICE_ATTR_2_RW(in4_max, adc128_in, 4, 2);
 295
 296 static SENSOR_DEVICE_ATTR_2_RO(in5_input, adc128_in, 5, 0);
 297 static SENSOR_DEVICE_ATTR_2_RW(in5_min, adc128_in, 5, 1);
 298 static SENSOR_DEVICE_ATTR_2_RW(in5_max, adc128_in, 5, 2);
 299
 300 static SENSOR_DEVICE_ATTR_2_RO(in6_input, adc128_in, 6, 0);
 301 static SENSOR_DEVICE_ATTR_2_RW(in6_min, adc128_in, 6, 1);
 302 static SENSOR_DEVICE_ATTR_2_RW(in6_max, adc128_in, 6, 2);
 303
 304 static SENSOR_DEVICE_ATTR_2_RO(in7_input, adc128_in, 7, 0);
 305 static SENSOR_DEVICE_ATTR_2_RW(in7_min, adc128_in, 7, 1);
 306 static SENSOR_DEVICE_ATTR_2_RW(in7_max, adc128_in, 7, 2);
 307
 308 static SENSOR_DEVICE_ATTR_RO(temp1_input, adc128_temp, 0);
 309 static SENSOR_DEVICE_ATTR_RW(temp1_max, adc128_temp, 1);
 310 static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, adc128_temp, 2);
 311
 312 static SENSOR_DEVICE_ATTR_RO(in0_alarm, adc128_alarm, 0);
 313 static SENSOR_DEVICE_ATTR_RO(in1_alarm, adc128_alarm, 1);
 314 static SENSOR_DEVICE_ATTR_RO(in2_alarm, adc128_alarm, 2);
 315 static SENSOR_DEVICE_ATTR_RO(in3_alarm, adc128_alarm, 3);
 316 static SENSOR_DEVICE_ATTR_RO(in4_alarm, adc128_alarm, 4);
 317 static SENSOR_DEVICE_ATTR_RO(in5_alarm, adc128_alarm, 5);
 318 static SENSOR_DEVICE_ATTR_RO(in6_alarm, adc128_alarm, 6);
 319 static SENSOR_DEVICE_ATTR_RO(in7_alarm, adc128_alarm, 7);
 320 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adc128_alarm, 7);
 321
 322 static struct attribute *adc128_attrs[] = {
 323         &sensor_dev_attr_in0_alarm.dev_attr.attr,
 324         &sensor_dev_attr_in0_input.dev_attr.attr,
 325         &sensor_dev_attr_in0_max.dev_attr.attr,
 326         &sensor_dev_attr_in0_min.dev_attr.attr,
 327         &sensor_dev_attr_in1_alarm.dev_attr.attr,
 328         &sensor_dev_attr_in1_input.dev_attr.attr,
 329         &sensor_dev_attr_in1_max.dev_attr.attr,
 330         &sensor_dev_attr_in1_min.dev_attr.attr,
 331         &sensor_dev_attr_in2_alarm.dev_attr.attr,
 332         &sensor_dev_attr_in2_input.dev_attr.attr,
 333         &sensor_dev_attr_in2_max.dev_attr.attr,
 334         &sensor_dev_attr_in2_min.dev_attr.attr,
 335         &sensor_dev_attr_in3_alarm.dev_attr.attr,
 336         &sensor_dev_attr_in3_input.dev_attr.attr,
 337         &sensor_dev_attr_in3_max.dev_attr.attr,
 338         &sensor_dev_attr_in3_min.dev_attr.attr,
 339         &sensor_dev_attr_in4_alarm.dev_attr.attr,
 340         &sensor_dev_attr_in4_input.dev_attr.attr,
 341         &sensor_dev_attr_in4_max.dev_attr.attr,
 342         &sensor_dev_attr_in4_min.dev_attr.attr,
 343         &sensor_dev_attr_in5_alarm.dev_attr.attr,
 344         &sensor_dev_attr_in5_input.dev_attr.attr,
 345         &sensor_dev_attr_in5_max.dev_attr.attr,
 346         &sensor_dev_attr_in5_min.dev_attr.attr,
 347         &sensor_dev_attr_in6_alarm.dev_attr.attr,
 348         &sensor_dev_attr_in6_input.dev_attr.attr,
 349         &sensor_dev_attr_in6_max.dev_attr.attr,
 350         &sensor_dev_attr_in6_min.dev_attr.attr,
 351         &sensor_dev_attr_in7_alarm.dev_attr.attr,
 352         &sensor_dev_attr_in7_input.dev_attr.attr,
 353         &sensor_dev_attr_in7_max.dev_attr.attr,
 354         &sensor_dev_attr_in7_min.dev_attr.attr,
 355         &sensor_dev_attr_temp1_input.dev_attr.attr,
 356         &sensor_dev_attr_temp1_max.dev_attr.attr,
 357         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 358         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 359         NULL
 360 };
 361
 362 static const struct attribute_group adc128_group = {
 363         .attrs = adc128_attrs,
 364         .is_visible = adc128_is_visible,
 365 };
 366 __ATTRIBUTE_GROUPS(adc128);
 367
 368 static int adc128_detect(struct i2c_client *client, struct i2c_board_info *info)
 369 {
 370         int man_id, dev_id;
 371
 372         if (!i2c_check_functionality(client->adapter,
 373                                      I2C_FUNC_SMBUS_BYTE_DATA |
 374                                      I2C_FUNC_SMBUS_WORD_DATA))
 375                 return -ENODEV;
 376
 377         man_id = i2c_smbus_read_byte_data(client, ADC128_REG_MAN_ID);
 378         dev_id = i2c_smbus_read_byte_data(client, ADC128_REG_DEV_ID);
 379         if (man_id != 0x01 || dev_id != 0x09)
 380                 return -ENODEV;
 381
 382         /* Check unused bits for confirmation */
 383         if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG) & 0xf4)
 384                 return -ENODEV;
 385         if (i2c_smbus_read_byte_data(client, ADC128_REG_CONV_RATE) & 0xfe)
 386                 return -ENODEV;
 387         if (i2c_smbus_read_byte_data(client, ADC128_REG_ONESHOT) & 0xfe)
 388                 return -ENODEV;
 389         if (i2c_smbus_read_byte_data(client, ADC128_REG_SHUTDOWN) & 0xfe)
 390                 return -ENODEV;
 391         if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV) & 0xf8)
 392                 return -ENODEV;
 393         if (i2c_smbus_read_byte_data(client, ADC128_REG_BUSY_STATUS) & 0xfc)
 394                 return -ENODEV;
 395
 396         strlcpy(info->type, "adc128d818", I2C_NAME_SIZE);
 397
 398         return 0;
 399 }
 400
 401 static int adc128_init_client(struct adc128_data *data)
 402 {
 403         struct i2c_client *client = data->client;
 404         int err;
 405
 406         /*
 407          * Reset chip to defaults.
 408          * This makes most other initializations unnecessary.
 409          */
 410         err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x80);
 411         if (err)
 412                 return err;
 413
 414         /* Set operation mode, if non-default */
 415         if (data->mode != 0) {
 416                 err = i2c_smbus_write_byte_data(client,
 417                                                 ADC128_REG_CONFIG_ADV,
 418                                                 data->mode << 1);
 419                 if (err)
 420                         return err;
 421         }
 422
 423         /* Start monitoring */
 424         err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x01);
 425         if (err)
 426                 return err;
 427
 428         /* If external vref is selected, configure the chip to use it */
 429         if (data->regulator) {
 430                 err = i2c_smbus_write_byte_data(client,
 431                                                 ADC128_REG_CONFIG_ADV, 0x01);
 432                 if (err)
 433                         return err;
 434         }
 435
 436         return 0;
 437 }
 438
 439 static int adc128_probe(struct i2c_client *client,
 440                         const struct i2c_device_id *id)
 441 {
 442         struct device *dev = &client->dev;
 443         struct regulator *regulator;
 444         struct device *hwmon_dev;
 445         struct adc128_data *data;
 446         int err, vref;
 447
 448         data = devm_kzalloc(dev, sizeof(struct adc128_data), GFP_KERNEL);
 449         if (!data)
 450                 return -ENOMEM;
 451
 452         /* vref is optional. If specified, is used as chip reference voltage */
 453         regulator = devm_regulator_get_optional(dev, "vref");
 454         if (!IS_ERR(regulator)) {
 455                 data->regulator = regulator;
 456                 err = regulator_enable(regulator);
 457                 if (err < 0)
 458                         return err;
 459                 vref = regulator_get_voltage(regulator);
 460                 if (vref < 0) {
 461                         err = vref;
 462                         goto error;
 463                 }
 464                 data->vref = DIV_ROUND_CLOSEST(vref, 1000);
 465         } else {
 466                 data->vref = 2560;      /* 2.56V, in mV */
 467         }
 468
 469         /* Operation mode is optional. If unspecified, keep current mode */
 470         if (of_property_read_u8(dev->of_node, "ti,mode", &data->mode) == 0) {
 471                 if (data->mode > 3) {
 472                         dev_err(dev, "invalid operation mode %d\n",
 473                                 data->mode);
 474                         err = -EINVAL;
 475                         goto error;
 476                 }
 477         } else {
 478                 err = i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV);
 479                 if (err < 0)
 480                         goto error;
 481                 data->mode = (err >> 1) & ADC128_REG_MASK;
 482         }
 483
 484         data->client = client;
 485         i2c_set_clientdata(client, data);
 486         mutex_init(&data->update_lock);
 487
 488         /* Initialize the chip */
 489         err = adc128_init_client(data);
 490         if (err < 0)
 491                 goto error;
 492
 493         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 494                                                            data, adc128_groups);
 495         if (IS_ERR(hwmon_dev)) {
 496                 err = PTR_ERR(hwmon_dev);
 497                 goto error;
 498         }
 499
 500         return 0;
 501
 502 error:
 503         if (data->regulator)
 504                 regulator_disable(data->regulator);
 505         return err;
 506 }
 507
 508 static int adc128_remove(struct i2c_client *client)
 509 {
 510         struct adc128_data *data = i2c_get_clientdata(client);
 511
 512         if (data->regulator)
 513                 regulator_disable(data->regulator);
 514
 515         return 0;
 516 }
 517
 518 static const struct i2c_device_id adc128_id[] = {
 519         { "adc128d818", 0 },
 520         { }
 521 };
 522 MODULE_DEVICE_TABLE(i2c, adc128_id);
 523
 524 static const struct of_device_id adc128_of_match[] = {
 525         { .compatible = "ti,adc128d818" },
 526         { },
 527 };
 528 MODULE_DEVICE_TABLE(of, adc128_of_match);
 529
 530 static struct i2c_driver adc128_driver = {
 531         .class          = I2C_CLASS_HWMON,
 532         .driver = {
 533                 .name   = "adc128d818",
 534                 .of_match_table = of_match_ptr(adc128_of_match),
 535         },
 536         .probe          = adc128_probe,
 537         .remove         = adc128_remove,
 538         .id_table       = adc128_id,
 539         .detect         = adc128_detect,
 540         .address_list   = normal_i2c,
 541 };
 542
 543 module_i2c_driver(adc128_driver);
 544
 545 MODULE_AUTHOR("Guenter Roeck");
 546 MODULE_DESCRIPTION("Driver for ADC128D818");
 547 MODULE_LICENSE("GPL");