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         int 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_vdd(struct device *dev,
 118                                 struct device_attribute *attr, char *buf)
 119 {
 120         struct adt7411_data *data = dev_get_drvdata(dev);
 121         struct i2c_client *client = data->client;
 122         int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 123                         ADT7411_REG_VDD_MSB, 2);
 124
 125         return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
 126 }
 127
 128 static ssize_t adt7411_show_temp(struct device *dev,
 129                         struct device_attribute *attr, char *buf)
 130 {
 131         int nr = to_sensor_dev_attr(attr)->index;
 132         struct adt7411_data *data = dev_get_drvdata(dev);
 133         struct i2c_client *client = data->client;
 134         int val;
 135         struct {
 136                 u8 low;
 137                 u8 high;
 138         } reg[2] = {
 139                 { ADT7411_REG_INT_TEMP_VDD_LSB, ADT7411_REG_INT_TEMP_MSB },
 140                 { ADT7411_REG_EXT_TEMP_AIN14_LSB,
 141                   ADT7411_REG_EXT_TEMP_AIN1_MSB },
 142         };
 143
 144         val = adt7411_read_10_bit(client, reg[nr].low, reg[nr].high, 0);
 145         if (val < 0)
 146                 return val;
 147
 148         val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
 149
 150         return sprintf(buf, "%d\n", val * 250);
 151 }
 152
 153 static ssize_t adt7411_show_input(struct device *dev,
 154                                   struct device_attribute *attr, char *buf)
 155 {
 156         int nr = to_sensor_dev_attr(attr)->index;
 157         struct adt7411_data *data = dev_get_drvdata(dev);
 158         struct i2c_client *client = data->client;
 159         int val;
 160         u8 lsb_reg, lsb_shift;
 161
 162         mutex_lock(&data->update_lock);
 163         if (time_after_eq(jiffies, data->next_update)) {
 164                 val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
 165                 if (val < 0)
 166                         goto exit_unlock;
 167
 168                 if (val & ADT7411_CFG3_REF_VDD) {
 169                         val = adt7411_read_10_bit(client,
 170                                         ADT7411_REG_INT_TEMP_VDD_LSB,
 171                                         ADT7411_REG_VDD_MSB, 2);
 172                         if (val < 0)
 173                                 goto exit_unlock;
 174
 175                         data->vref_cached = val * 7000 / 1024;
 176                 } else {
 177                         data->vref_cached = 2250;
 178                 }
 179
 180                 data->next_update = jiffies + HZ;
 181         }
 182
 183         lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
 184         lsb_shift = 2 * (nr & 0x03);
 185         val = adt7411_read_10_bit(client, lsb_reg,
 186                         ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
 187         if (val < 0)
 188                 goto exit_unlock;
 189
 190         val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
 191  exit_unlock:
 192         mutex_unlock(&data->update_lock);
 193         return val;
 194 }
 195
 196 static ssize_t adt7411_show_bit(struct device *dev,
 197                                 struct device_attribute *attr, char *buf)
 198 {
 199         struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
 200         struct adt7411_data *data = dev_get_drvdata(dev);
 201         struct i2c_client *client = data->client;
 202         int ret = i2c_smbus_read_byte_data(client, attr2->index);
 203
 204         return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
 205 }
 206
 207 static ssize_t adt7411_set_bit(struct device *dev,
 208                                struct device_attribute *attr, const char *buf,
 209                                size_t count)
 210 {
 211         struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
 212         struct adt7411_data *data = dev_get_drvdata(dev);
 213         struct i2c_client *client = data->client;
 214         int ret;
 215         unsigned long flag;
 216
 217         ret = kstrtoul(buf, 0, &flag);
 218         if (ret || flag > 1)
 219                 return -EINVAL;
 220
 221         ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
 222
 223         /* force update */
 224         mutex_lock(&data->update_lock);
 225         data->next_update = jiffies;
 226         mutex_unlock(&data->update_lock);
 227
 228         return ret < 0 ? ret : count;
 229 }
 230
 231
 232 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
 233         SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
 234         adt7411_set_bit, __bit, __reg)
 235
 236 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL, 0);
 237 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, adt7411_show_temp, NULL, 1);
 238 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
 239 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
 240 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
 241 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
 242 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
 243 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
 244 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
 245 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
 246 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
 247 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
 248 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
 249 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
 250
 251 static struct attribute *adt7411_attrs[] = {
 252         &sensor_dev_attr_temp1_input.dev_attr.attr,
 253         &sensor_dev_attr_temp2_input.dev_attr.attr,
 254         &dev_attr_in0_input.attr,
 255         &sensor_dev_attr_in1_input.dev_attr.attr,
 256         &sensor_dev_attr_in2_input.dev_attr.attr,
 257         &sensor_dev_attr_in3_input.dev_attr.attr,
 258         &sensor_dev_attr_in4_input.dev_attr.attr,
 259         &sensor_dev_attr_in5_input.dev_attr.attr,
 260         &sensor_dev_attr_in6_input.dev_attr.attr,
 261         &sensor_dev_attr_in7_input.dev_attr.attr,
 262         &sensor_dev_attr_in8_input.dev_attr.attr,
 263         &sensor_dev_attr_no_average.dev_attr.attr,
 264         &sensor_dev_attr_fast_sampling.dev_attr.attr,
 265         &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
 266         NULL
 267 };
 268
 269 static umode_t adt7411_attrs_visible(struct kobject *kobj,
 270                                      struct attribute *attr, int index)
 271 {
 272         struct device *dev = container_of(kobj, struct device, kobj);
 273         struct adt7411_data *data = dev_get_drvdata(dev);
 274         bool visible = true;
 275
 276         if (attr == &sensor_dev_attr_temp2_input.dev_attr.attr)
 277                 visible = data->use_ext_temp;
 278         else if (attr == &sensor_dev_attr_in1_input.dev_attr.attr ||
 279                  attr == &sensor_dev_attr_in2_input.dev_attr.attr)
 280                 visible = !data->use_ext_temp;
 281
 282         return visible ? attr->mode : 0;
 283 }
 284
 285 static const struct attribute_group adt7411_group = {
 286         .attrs = adt7411_attrs,
 287         .is_visible = adt7411_attrs_visible,
 288 };
 289 __ATTRIBUTE_GROUPS(adt7411);
 290
 291 static int adt7411_detect(struct i2c_client *client,
 292                           struct i2c_board_info *info)
 293 {
 294         int val;
 295
 296         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 297                 return -ENODEV;
 298
 299         val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
 300         if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
 301                 dev_dbg(&client->dev,
 302                         "Wrong manufacturer ID. Got %d, expected %d\n",
 303                         val, ADT7411_MANUFACTURER_ID);
 304                 return -ENODEV;
 305         }
 306
 307         val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
 308         if (val < 0 || val != ADT7411_DEVICE_ID) {
 309                 dev_dbg(&client->dev,
 310                         "Wrong device ID. Got %d, expected %d\n",
 311                         val, ADT7411_DEVICE_ID);
 312                 return -ENODEV;
 313         }
 314
 315         strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
 316
 317         return 0;
 318 }
 319
 320 static int adt7411_init_device(struct adt7411_data *data)
 321 {
 322         int ret;
 323         u8 val;
 324
 325         ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG3);
 326         if (ret < 0)
 327                 return ret;
 328
 329         /*
 330          * We must only write zero to bit 1 and bit 2 and only one to bit 3
 331          * according to the datasheet.
 332          */
 333         val = ret;
 334         val &= ~(ADT7411_CFG3_RESERVED_BIT1 | ADT7411_CFG3_RESERVED_BIT2);
 335         val |= ADT7411_CFG3_RESERVED_BIT3;
 336
 337         ret = i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG3, val);
 338         if (ret < 0)
 339                 return ret;
 340
 341         ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG1);
 342         if (ret < 0)
 343                 return ret;
 344
 345         data->use_ext_temp = ret & ADT7411_CFG1_EXT_TDM;
 346
 347         /*
 348          * We must only write zero to bit 1 and only one to bit 3 according to
 349          * the datasheet.
 350          */
 351         val = ret;
 352         val &= ~ADT7411_CFG1_RESERVED_BIT1;
 353         val |= ADT7411_CFG1_RESERVED_BIT3;
 354
 355         /* enable monitoring */
 356         val |= ADT7411_CFG1_START_MONITOR;
 357
 358         return i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG1, val);
 359 }
 360
 361 static int adt7411_probe(struct i2c_client *client,
 362                                    const struct i2c_device_id *id)
 363 {
 364         struct device *dev = &client->dev;
 365         struct adt7411_data *data;
 366         struct device *hwmon_dev;
 367         int ret;
 368
 369         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 370         if (!data)
 371                 return -ENOMEM;
 372
 373         i2c_set_clientdata(client, data);
 374         data->client = client;
 375         mutex_init(&data->device_lock);
 376         mutex_init(&data->update_lock);
 377
 378         ret = adt7411_init_device(data);
 379         if (ret < 0)
 380                 return ret;
 381
 382         /* force update on first occasion */
 383         data->next_update = jiffies;
 384
 385         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 386                                                            data,
 387                                                            adt7411_groups);
 388         return PTR_ERR_OR_ZERO(hwmon_dev);
 389 }
 390
 391 static const struct i2c_device_id adt7411_id[] = {
 392         { "adt7411", 0 },
 393         { }
 394 };
 395 MODULE_DEVICE_TABLE(i2c, adt7411_id);
 396
 397 static struct i2c_driver adt7411_driver = {
 398         .driver         = {
 399                 .name           = "adt7411",
 400         },
 401         .probe  = adt7411_probe,
 402         .id_table = adt7411_id,
 403         .detect = adt7411_detect,
 404         .address_list = normal_i2c,
 405         .class = I2C_CLASS_HWMON,
 406 };
 407
 408 module_i2c_driver(adt7411_driver);
 409
 410 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
 411         "Wolfram Sang <w.sang@pengutronix.de>");
 412 MODULE_DESCRIPTION("ADT7411 driver");
 413 MODULE_LICENSE("GPL v2");