drivers/hwmon/adt7411.c

   1 /*
   2  *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
   3  *
   4  *  Copyright (C) 2008, 2010 Pengutronix
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License version 2 as
   8  *  published by the Free Software Foundation.
   9  *
  10  *  TODO: SPI, use power-down mode for suspend?, interrupt handling?
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/err.h>
  17 #include <linux/mutex.h>
  18 #include <linux/jiffies.h>
  19 #include <linux/i2c.h>
  20 #include <linux/hwmon.h>
  21 #include <linux/hwmon-sysfs.h>
  22 #include <linux/slab.h>
  23
  24 #define ADT7411_REG_INT_TEMP_VDD_LSB            0x03
  25 #define ADT7411_REG_EXT_TEMP_AIN14_LSB          0x04
  26 #define ADT7411_REG_VDD_MSB                     0x06
  27 #define ADT7411_REG_INT_TEMP_MSB                0x07
  28 #define ADT7411_REG_EXT_TEMP_AIN1_MSB           0x08
  29
  30 #define ADT7411_REG_CFG1                        0x18
  31 #define ADT7411_CFG1_START_MONITOR              (1 << 0)
  32 #define ADT7411_CFG1_RESERVED_BIT1              (1 << 1)
  33 #define ADT7411_CFG1_EXT_TDM                    (1 << 2)
  34 #define ADT7411_CFG1_RESERVED_BIT3              (1 << 3)
  35
  36 #define ADT7411_REG_CFG2                        0x19
  37 #define ADT7411_CFG2_DISABLE_AVG                (1 << 5)
  38
  39 #define ADT7411_REG_CFG3                        0x1a
  40 #define ADT7411_CFG3_ADC_CLK_225                (1 << 0)
  41 #define ADT7411_CFG3_RESERVED_BIT1              (1 << 1)
  42 #define ADT7411_CFG3_RESERVED_BIT2              (1 << 2)
  43 #define ADT7411_CFG3_RESERVED_BIT3              (1 << 3)
  44 #define ADT7411_CFG3_REF_VDD                    (1 << 4)
  45
  46 #define ADT7411_REG_DEVICE_ID                   0x4d
  47 #define ADT7411_REG_MANUFACTURER_ID             0x4e
  48
  49 #define ADT7411_DEVICE_ID                       0x2
  50 #define ADT7411_MANUFACTURER_ID                 0x41
  51
  52 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
  53
  54 struct adt7411_data {
  55         struct mutex device_lock;       /* for "atomic" device accesses */
  56         struct mutex update_lock;
  57         unsigned long next_update;
  58         long vref_cached;
  59         struct i2c_client *client;
  60         bool use_ext_temp;
  61 };
  62
  63 /*
  64  * When reading a register containing (up to 4) lsb, all associated
  65  * msb-registers get locked by the hardware. After _one_ of those msb is read,
  66  * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
  67  * is protected here with a mutex, too.
  68  */
  69 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
  70                                 u8 msb_reg, u8 lsb_shift)
  71 {
  72         struct adt7411_data *data = i2c_get_clientdata(client);
  73         int val, tmp;
  74
  75         mutex_lock(&data->device_lock);
  76
  77         val = i2c_smbus_read_byte_data(client, lsb_reg);
  78         if (val < 0)
  79                 goto exit_unlock;
  80
  81         tmp = (val >> lsb_shift) & 3;
  82         val = i2c_smbus_read_byte_data(client, msb_reg);
  83
  84         if (val >= 0)
  85                 val = (val << 2) | tmp;
  86
  87  exit_unlock:
  88         mutex_unlock(&data->device_lock);
  89
  90         return val;
  91 }
  92
  93 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
  94                                 bool flag)
  95 {
  96         struct adt7411_data *data = i2c_get_clientdata(client);
  97         int ret, val;
  98
  99         mutex_lock(&data->device_lock);
 100
 101         ret = i2c_smbus_read_byte_data(client, reg);
 102         if (ret < 0)
 103                 goto exit_unlock;
 104
 105         if (flag)
 106                 val = ret | bit;
 107         else
 108                 val = ret & ~bit;
 109
 110         ret = i2c_smbus_write_byte_data(client, reg, val);
 111
 112  exit_unlock:
 113         mutex_unlock(&data->device_lock);
 114         return ret;
 115 }
 116
 117 static ssize_t adt7411_show_bit(struct device *dev,
 118                                 struct device_attribute *attr, char *buf)
 119 {
 120         struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
 121         struct adt7411_data *data = dev_get_drvdata(dev);
 122         struct i2c_client *client = data->client;
 123         int ret = i2c_smbus_read_byte_data(client, attr2->index);
 124
 125         return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
 126 }
 127
 128 static ssize_t adt7411_set_bit(struct device *dev,
 129                                struct device_attribute *attr, const char *buf,
 130                                size_t count)
 131 {
 132         struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
 133         struct adt7411_data *data = dev_get_drvdata(dev);
 134         struct i2c_client *client = data->client;
 135         int ret;
 136         unsigned long flag;
 137
 138         ret = kstrtoul(buf, 0, &flag);
 139         if (ret || flag > 1)
 140                 return -EINVAL;
 141
 142         ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
 143
 144         /* force update */
 145         mutex_lock(&data->update_lock);
 146         data->next_update = jiffies;
 147         mutex_unlock(&data->update_lock);
 148
 149         return ret < 0 ? ret : count;
 150 }
 151
 152 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
 153         SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
 154         adt7411_set_bit, __bit, __reg)
 155
 156 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
 157 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
 158 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
 159
 160 static struct attribute *adt7411_attrs[] = {
 161         &sensor_dev_attr_no_average.dev_attr.attr,
 162         &sensor_dev_attr_fast_sampling.dev_attr.attr,
 163         &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
 164         NULL
 165 };
 166 ATTRIBUTE_GROUPS(adt7411);
 167
 168 static int adt7411_read_in_vdd(struct device *dev, u32 attr, long *val)
 169 {
 170         struct adt7411_data *data = dev_get_drvdata(dev);
 171         struct i2c_client *client = data->client;
 172         int ret;
 173
 174         switch (attr) {
 175         case hwmon_in_input:
 176                 ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 177                                           ADT7411_REG_VDD_MSB, 2);
 178                 if (ret < 0)
 179                         return ret;
 180                 *val = ret * 7000 / 1024;
 181                 return 0;
 182         default:
 183                 return -EOPNOTSUPP;
 184         }
 185 }
 186
 187 static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
 188                                 long *val)
 189 {
 190         struct adt7411_data *data = dev_get_drvdata(dev);
 191         struct i2c_client *client = data->client;
 192
 193         int ret;
 194         int lsb_reg, lsb_shift;
 195         int nr = channel - 1;
 196
 197         mutex_lock(&data->update_lock);
 198         if (time_after_eq(jiffies, data->next_update)) {
 199                 ret = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
 200                 if (ret < 0)
 201                         goto exit_unlock;
 202
 203                 if (ret & ADT7411_CFG3_REF_VDD) {
 204                         ret = adt7411_read_in_vdd(dev, hwmon_in_input,
 205                                                   &data->vref_cached);
 206                         if (ret < 0)
 207                                 goto exit_unlock;
 208                 } else {
 209                         data->vref_cached = 2250;
 210                 }
 211
 212                 data->next_update = jiffies + HZ;
 213         }
 214
 215         switch (attr) {
 216         case hwmon_in_input:
 217                 lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
 218                 lsb_shift = 2 * (nr & 0x03);
 219                 ret = adt7411_read_10_bit(client, lsb_reg,
 220                                           ADT7411_REG_EXT_TEMP_AIN1_MSB + nr,
 221                                           lsb_shift);
 222                 if (ret < 0)
 223                         goto exit_unlock;
 224                 *val = ret * data->vref_cached / 1024;
 225                 ret = 0;
 226                 break;
 227         default:
 228                 ret = -EOPNOTSUPP;
 229                 break;
 230         }
 231  exit_unlock:
 232         mutex_unlock(&data->update_lock);
 233         return ret;
 234 }
 235
 236 static int adt7411_read_in(struct device *dev, u32 attr, int channel,
 237                            long *val)
 238 {
 239         if (channel == 0)
 240                 return adt7411_read_in_vdd(dev, attr, val);
 241         else
 242                 return adt7411_read_in_chan(dev, attr, channel, val);
 243 }
 244
 245 static int adt7411_read_temp(struct device *dev, u32 attr, int channel,
 246                              long *val)
 247 {
 248         struct adt7411_data *data = dev_get_drvdata(dev);
 249         struct i2c_client *client = data->client;
 250         int ret, regl, regh;
 251
 252         switch (attr) {
 253         case hwmon_temp_input:
 254                 regl = channel ? ADT7411_REG_EXT_TEMP_AIN14_LSB :
 255                                  ADT7411_REG_INT_TEMP_VDD_LSB;
 256                 regh = channel ? ADT7411_REG_EXT_TEMP_AIN1_MSB :
 257                                  ADT7411_REG_INT_TEMP_MSB;
 258                 ret = adt7411_read_10_bit(client, regl, regh, 0);
 259                 if (ret < 0)
 260                         return ret;
 261                 ret = ret & 0x200 ? ret - 0x400 : ret; /* 10 bit signed */
 262                 *val = ret * 250;
 263                 return 0;
 264         default:
 265                 return -EOPNOTSUPP;
 266         }
 267 }
 268
 269 static int adt7411_read(struct device *dev, enum hwmon_sensor_types type,
 270                         u32 attr, int channel, long *val)
 271 {
 272         switch (type) {
 273         case hwmon_in:
 274                 return adt7411_read_in(dev, attr, channel, val);
 275         case hwmon_temp:
 276                 return adt7411_read_temp(dev, attr, channel, val);
 277         default:
 278                 return -EOPNOTSUPP;
 279         }
 280 }
 281
 282 static umode_t adt7411_is_visible(const void *_data,
 283                                   enum hwmon_sensor_types type,
 284                                   u32 attr, int channel)
 285 {
 286         const struct adt7411_data *data = _data;
 287
 288         switch (type) {
 289         case hwmon_in:
 290                 if (channel > 0 && channel < 3)
 291                         return data->use_ext_temp ? 0 : S_IRUGO;
 292                 else
 293                         return S_IRUGO;
 294         case hwmon_temp:
 295                 if (channel == 1)
 296                         return data->use_ext_temp ? S_IRUGO : 0;
 297                 else
 298                         return S_IRUGO;
 299         default:
 300                 return 0;
 301         }
 302 }
 303
 304 static int adt7411_detect(struct i2c_client *client,
 305                           struct i2c_board_info *info)
 306 {
 307         int val;
 308
 309         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 310                 return -ENODEV;
 311
 312         val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
 313         if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
 314                 dev_dbg(&client->dev,
 315                         "Wrong manufacturer ID. Got %d, expected %d\n",
 316                         val, ADT7411_MANUFACTURER_ID);
 317                 return -ENODEV;
 318         }
 319
 320         val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
 321         if (val < 0 || val != ADT7411_DEVICE_ID) {
 322                 dev_dbg(&client->dev,
 323                         "Wrong device ID. Got %d, expected %d\n",
 324                         val, ADT7411_DEVICE_ID);
 325                 return -ENODEV;
 326         }
 327
 328         strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
 329
 330         return 0;
 331 }
 332
 333 static int adt7411_init_device(struct adt7411_data *data)
 334 {
 335         int ret;
 336         u8 val;
 337
 338         ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG3);
 339         if (ret < 0)
 340                 return ret;
 341
 342         /*
 343          * We must only write zero to bit 1 and bit 2 and only one to bit 3
 344          * according to the datasheet.
 345          */
 346         val = ret;
 347         val &= ~(ADT7411_CFG3_RESERVED_BIT1 | ADT7411_CFG3_RESERVED_BIT2);
 348         val |= ADT7411_CFG3_RESERVED_BIT3;
 349
 350         ret = i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG3, val);
 351         if (ret < 0)
 352                 return ret;
 353
 354         ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG1);
 355         if (ret < 0)
 356                 return ret;
 357
 358         data->use_ext_temp = ret & ADT7411_CFG1_EXT_TDM;
 359
 360         /*
 361          * We must only write zero to bit 1 and only one to bit 3 according to
 362          * the datasheet.
 363          */
 364         val = ret;
 365         val &= ~ADT7411_CFG1_RESERVED_BIT1;
 366         val |= ADT7411_CFG1_RESERVED_BIT3;
 367
 368         /* enable monitoring */
 369         val |= ADT7411_CFG1_START_MONITOR;
 370
 371         return i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG1, val);
 372 }
 373
 374 static const u32 adt7411_in_config[] = {
 375         HWMON_I_INPUT,
 376         HWMON_I_INPUT,
 377         HWMON_I_INPUT,
 378         HWMON_I_INPUT,
 379         HWMON_I_INPUT,
 380         HWMON_I_INPUT,
 381         HWMON_I_INPUT,
 382         HWMON_I_INPUT,
 383         HWMON_I_INPUT,
 384         0
 385 };
 386
 387 static const struct hwmon_channel_info adt7411_in = {
 388         .type = hwmon_in,
 389         .config = adt7411_in_config,
 390 };
 391
 392 static const u32 adt7411_temp_config[] = {
 393         HWMON_T_INPUT,
 394         HWMON_T_INPUT,
 395         0
 396 };
 397
 398 static const struct hwmon_channel_info adt7411_temp = {
 399         .type = hwmon_temp,
 400         .config = adt7411_temp_config,
 401 };
 402
 403 static const struct hwmon_channel_info *adt7411_info[] = {
 404         &adt7411_in,
 405         &adt7411_temp,
 406         NULL
 407 };
 408
 409 static const struct hwmon_ops adt7411_hwmon_ops = {
 410         .is_visible = adt7411_is_visible,
 411         .read = adt7411_read,
 412 };
 413
 414 static const struct hwmon_chip_info adt7411_chip_info = {
 415         .ops = &adt7411_hwmon_ops,
 416         .info = adt7411_info,
 417 };
 418
 419 static int adt7411_probe(struct i2c_client *client,
 420                                    const struct i2c_device_id *id)
 421 {
 422         struct device *dev = &client->dev;
 423         struct adt7411_data *data;
 424         struct device *hwmon_dev;
 425         int ret;
 426
 427         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 428         if (!data)
 429                 return -ENOMEM;
 430
 431         i2c_set_clientdata(client, data);
 432         data->client = client;
 433         mutex_init(&data->device_lock);
 434         mutex_init(&data->update_lock);
 435
 436         ret = adt7411_init_device(data);
 437         if (ret < 0)
 438                 return ret;
 439
 440         /* force update on first occasion */
 441         data->next_update = jiffies;
 442
 443         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 444                                                          data,
 445                                                          &adt7411_chip_info,
 446                                                          adt7411_groups);
 447         return PTR_ERR_OR_ZERO(hwmon_dev);
 448 }
 449
 450 static const struct i2c_device_id adt7411_id[] = {
 451         { "adt7411", 0 },
 452         { }
 453 };
 454 MODULE_DEVICE_TABLE(i2c, adt7411_id);
 455
 456 static struct i2c_driver adt7411_driver = {
 457         .driver         = {
 458                 .name           = "adt7411",
 459         },
 460         .probe  = adt7411_probe,
 461         .id_table = adt7411_id,
 462         .detect = adt7411_detect,
 463         .address_list = normal_i2c,
 464         .class = I2C_CLASS_HWMON,
 465 };
 466
 467 module_i2c_driver(adt7411_driver);
 468
 469 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
 470         "Wolfram Sang <w.sang@pengutronix.de>");
 471 MODULE_DESCRIPTION("ADT7411 driver");
 472 MODULE_LICENSE("GPL v2");