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, support for external temperature sensor
  11  *        use power-down mode for suspend?, interrupt handling?
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/err.h>
  18 #include <linux/delay.h>
  19 #include <linux/mutex.h>
  20 #include <linux/jiffies.h>
  21 #include <linux/i2c.h>
  22 #include <linux/hwmon.h>
  23 #include <linux/hwmon-sysfs.h>
  24 #include <linux/slab.h>
  25
  26 #define ADT7411_REG_INT_TEMP_VDD_LSB            0x03
  27 #define ADT7411_REG_EXT_TEMP_AIN14_LSB          0x04
  28 #define ADT7411_REG_VDD_MSB                     0x06
  29 #define ADT7411_REG_INT_TEMP_MSB                0x07
  30 #define ADT7411_REG_EXT_TEMP_AIN1_MSB           0x08
  31
  32 #define ADT7411_REG_CFG1                        0x18
  33 #define ADT7411_CFG1_START_MONITOR              (1 << 0)
  34
  35 #define ADT7411_REG_CFG2                        0x19
  36 #define ADT7411_CFG2_DISABLE_AVG                (1 << 5)
  37
  38 #define ADT7411_REG_CFG3                        0x1a
  39 #define ADT7411_CFG3_ADC_CLK_225                (1 << 0)
  40 #define ADT7411_CFG3_REF_VDD                    (1 << 4)
  41
  42 #define ADT7411_REG_DEVICE_ID                   0x4d
  43 #define ADT7411_REG_MANUFACTURER_ID             0x4e
  44
  45 #define ADT7411_DEVICE_ID                       0x2
  46 #define ADT7411_MANUFACTURER_ID                 0x41
  47
  48 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
  49
  50 struct adt7411_data {
  51         struct mutex device_lock;       /* for "atomic" device accesses */
  52         struct mutex update_lock;
  53         unsigned long next_update;
  54         int vref_cached;
  55         struct device *hwmon_dev;
  56 };
  57
  58 /*
  59  * When reading a register containing (up to 4) lsb, all associated
  60  * msb-registers get locked by the hardware. After _one_ of those msb is read,
  61  * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
  62  * is protected here with a mutex, too.
  63  */
  64 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
  65                                 u8 msb_reg, u8 lsb_shift)
  66 {
  67         struct adt7411_data *data = i2c_get_clientdata(client);
  68         int val, tmp;
  69
  70         mutex_lock(&data->device_lock);
  71
  72         val = i2c_smbus_read_byte_data(client, lsb_reg);
  73         if (val < 0)
  74                 goto exit_unlock;
  75
  76         tmp = (val >> lsb_shift) & 3;
  77         val = i2c_smbus_read_byte_data(client, msb_reg);
  78
  79         if (val >= 0)
  80                 val = (val << 2) | tmp;
  81
  82  exit_unlock:
  83         mutex_unlock(&data->device_lock);
  84
  85         return val;
  86 }
  87
  88 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
  89                                 bool flag)
  90 {
  91         struct adt7411_data *data = i2c_get_clientdata(client);
  92         int ret, val;
  93
  94         mutex_lock(&data->device_lock);
  95
  96         ret = i2c_smbus_read_byte_data(client, reg);
  97         if (ret < 0)
  98                 goto exit_unlock;
  99
 100         if (flag)
 101                 val = ret | bit;
 102         else
 103                 val = ret & ~bit;
 104
 105         ret = i2c_smbus_write_byte_data(client, reg, val);
 106
 107  exit_unlock:
 108         mutex_unlock(&data->device_lock);
 109         return ret;
 110 }
 111
 112 static ssize_t adt7411_show_vdd(struct device *dev,
 113                                 struct device_attribute *attr, char *buf)
 114 {
 115         struct i2c_client *client = to_i2c_client(dev);
 116         int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 117                         ADT7411_REG_VDD_MSB, 2);
 118
 119         return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
 120 }
 121
 122 static ssize_t adt7411_show_temp(struct device *dev,
 123                         struct device_attribute *attr, char *buf)
 124 {
 125         struct i2c_client *client = to_i2c_client(dev);
 126         int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 127                         ADT7411_REG_INT_TEMP_MSB, 0);
 128
 129         if (val < 0)
 130                 return val;
 131
 132         val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
 133
 134         return sprintf(buf, "%d\n", val * 250);
 135 }
 136
 137 static ssize_t adt7411_show_input(struct device *dev,
 138                                   struct device_attribute *attr, char *buf)
 139 {
 140         int nr = to_sensor_dev_attr(attr)->index;
 141         struct i2c_client *client = to_i2c_client(dev);
 142         struct adt7411_data *data = i2c_get_clientdata(client);
 143         int val;
 144         u8 lsb_reg, lsb_shift;
 145
 146         mutex_lock(&data->update_lock);
 147         if (time_after_eq(jiffies, data->next_update)) {
 148                 val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
 149                 if (val < 0)
 150                         goto exit_unlock;
 151
 152                 if (val & ADT7411_CFG3_REF_VDD) {
 153                         val = adt7411_read_10_bit(client,
 154                                         ADT7411_REG_INT_TEMP_VDD_LSB,
 155                                         ADT7411_REG_VDD_MSB, 2);
 156                         if (val < 0)
 157                                 goto exit_unlock;
 158
 159                         data->vref_cached = val * 7000 / 1024;
 160                 } else {
 161                         data->vref_cached = 2250;
 162                 }
 163
 164                 data->next_update = jiffies + HZ;
 165         }
 166
 167         lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
 168         lsb_shift = 2 * (nr & 0x03);
 169         val = adt7411_read_10_bit(client, lsb_reg,
 170                         ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
 171         if (val < 0)
 172                 goto exit_unlock;
 173
 174         val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
 175  exit_unlock:
 176         mutex_unlock(&data->update_lock);
 177         return val;
 178 }
 179
 180 static ssize_t adt7411_show_bit(struct device *dev,
 181                                 struct device_attribute *attr, char *buf)
 182 {
 183         struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
 184         struct i2c_client *client = to_i2c_client(dev);
 185         int ret = i2c_smbus_read_byte_data(client, attr2->index);
 186
 187         return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
 188 }
 189
 190 static ssize_t adt7411_set_bit(struct device *dev,
 191                                struct device_attribute *attr, const char *buf,
 192                                size_t count)
 193 {
 194         struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
 195         struct i2c_client *client = to_i2c_client(dev);
 196         struct adt7411_data *data = i2c_get_clientdata(client);
 197         int ret;
 198         unsigned long flag;
 199
 200         ret = strict_strtoul(buf, 0, &flag);
 201         if (ret || flag > 1)
 202                 return -EINVAL;
 203
 204         ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
 205
 206         /* force update */
 207         mutex_lock(&data->update_lock);
 208         data->next_update = jiffies;
 209         mutex_unlock(&data->update_lock);
 210
 211         return ret < 0 ? ret : count;
 212 }
 213
 214 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
 215         SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
 216         adt7411_set_bit, __bit, __reg)
 217
 218 static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
 219 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
 220 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
 221 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
 222 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
 223 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
 224 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
 225 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
 226 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
 227 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
 228 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
 229 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
 230 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
 231
 232 static struct attribute *adt7411_attrs[] = {
 233         &dev_attr_temp1_input.attr,
 234         &dev_attr_in0_input.attr,
 235         &sensor_dev_attr_in1_input.dev_attr.attr,
 236         &sensor_dev_attr_in2_input.dev_attr.attr,
 237         &sensor_dev_attr_in3_input.dev_attr.attr,
 238         &sensor_dev_attr_in4_input.dev_attr.attr,
 239         &sensor_dev_attr_in5_input.dev_attr.attr,
 240         &sensor_dev_attr_in6_input.dev_attr.attr,
 241         &sensor_dev_attr_in7_input.dev_attr.attr,
 242         &sensor_dev_attr_in8_input.dev_attr.attr,
 243         &sensor_dev_attr_no_average.dev_attr.attr,
 244         &sensor_dev_attr_fast_sampling.dev_attr.attr,
 245         &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
 246         NULL
 247 };
 248
 249 static const struct attribute_group adt7411_attr_grp = {
 250         .attrs = adt7411_attrs,
 251 };
 252
 253 static int adt7411_detect(struct i2c_client *client,
 254                           struct i2c_board_info *info)
 255 {
 256         int val;
 257
 258         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 259                 return -ENODEV;
 260
 261         val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
 262         if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
 263                 dev_dbg(&client->dev, "Wrong manufacturer ID. Got %d, "
 264                         "expected %d\n", val, ADT7411_MANUFACTURER_ID);
 265                 return -ENODEV;
 266         }
 267
 268         val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
 269         if (val < 0 || val != ADT7411_DEVICE_ID) {
 270                 dev_dbg(&client->dev, "Wrong device ID. Got %d, "
 271                         "expected %d\n", val, ADT7411_DEVICE_ID);
 272                 return -ENODEV;
 273         }
 274
 275         strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
 276
 277         return 0;
 278 }
 279
 280 static int __devinit adt7411_probe(struct i2c_client *client,
 281                                    const struct i2c_device_id *id)
 282 {
 283         struct adt7411_data *data;
 284         int ret;
 285
 286         data = kzalloc(sizeof(*data), GFP_KERNEL);
 287         if (!data)
 288                 return -ENOMEM;
 289
 290         i2c_set_clientdata(client, data);
 291         mutex_init(&data->device_lock);
 292         mutex_init(&data->update_lock);
 293
 294         ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
 295                                  ADT7411_CFG1_START_MONITOR, 1);
 296         if (ret < 0)
 297                 goto exit_free;
 298
 299         /* force update on first occasion */
 300         data->next_update = jiffies;
 301
 302         ret = sysfs_create_group(&client->dev.kobj, &adt7411_attr_grp);
 303         if (ret)
 304                 goto exit_free;
 305
 306         data->hwmon_dev = hwmon_device_register(&client->dev);
 307         if (IS_ERR(data->hwmon_dev)) {
 308                 ret = PTR_ERR(data->hwmon_dev);
 309                 goto exit_remove;
 310         }
 311
 312         dev_info(&client->dev, "successfully registered\n");
 313
 314         return 0;
 315
 316  exit_remove:
 317         sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
 318  exit_free:
 319         i2c_set_clientdata(client, NULL);
 320         kfree(data);
 321         return ret;
 322 }
 323
 324 static int __devexit adt7411_remove(struct i2c_client *client)
 325 {
 326         struct adt7411_data *data = i2c_get_clientdata(client);
 327
 328         hwmon_device_unregister(data->hwmon_dev);
 329         sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
 330         i2c_set_clientdata(client, NULL);
 331         kfree(data);
 332         return 0;
 333 }
 334
 335 static const struct i2c_device_id adt7411_id[] = {
 336         { "adt7411", 0 },
 337         { }
 338 };
 339
 340 static struct i2c_driver adt7411_driver = {
 341         .driver         = {
 342                 .name           = "adt7411",
 343         },
 344         .probe  = adt7411_probe,
 345         .remove = __devexit_p(adt7411_remove),
 346         .id_table = adt7411_id,
 347         .detect = adt7411_detect,
 348         .address_list = normal_i2c,
 349         .class = I2C_CLASS_HWMON,
 350 };
 351
 352 static int __init sensors_adt7411_init(void)
 353 {
 354         return i2c_add_driver(&adt7411_driver);
 355 }
 356 module_init(sensors_adt7411_init)
 357
 358 static void __exit sensors_adt7411_exit(void)
 359 {
 360         i2c_del_driver(&adt7411_driver);
 361 }
 362 module_exit(sensors_adt7411_exit)
 363
 364 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
 365         "Wolfram Sang <w.sang@pengutronix.de>");
 366 MODULE_DESCRIPTION("ADT7411 driver");
 367 MODULE_LICENSE("GPL v2");