drivers/hwmon/ad7418.c

   1 /*
   2  * An hwmon driver for the Analog Devices AD7416/17/18
   3  * Copyright (C) 2006-07 Tower Technologies
   4  *
   5  * Author: Alessandro Zummo <a.zummo@towertech.it>
   6  *
   7  * Based on lm75.c
   8  * Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
   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,
  12  * as published by the Free Software Foundation - version 2.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/i2c.h>
  18 #include <linux/hwmon.h>
  19 #include <linux/hwmon-sysfs.h>
  20 #include <linux/err.h>
  21 #include <linux/mutex.h>
  22 #include <linux/delay.h>
  23
  24 #include "lm75.h"
  25
  26 #define DRV_VERSION "0.4"
  27
  28 enum chips { ad7416, ad7417, ad7418 };
  29
  30 /* AD7418 registers */
  31 #define AD7418_REG_TEMP_IN      0x00
  32 #define AD7418_REG_CONF         0x01
  33 #define AD7418_REG_TEMP_HYST    0x02
  34 #define AD7418_REG_TEMP_OS      0x03
  35 #define AD7418_REG_ADC          0x04
  36 #define AD7418_REG_CONF2        0x05
  37
  38 #define AD7418_REG_ADC_CH(x)    ((x) << 5)
  39 #define AD7418_CH_TEMP          AD7418_REG_ADC_CH(0)
  40
  41 static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
  42                                         AD7418_REG_TEMP_HYST,
  43                                         AD7418_REG_TEMP_OS };
  44
  45 struct ad7418_data {
  46         struct device           *hwmon_dev;
  47         struct attribute_group  attrs;
  48         enum chips              type;
  49         struct mutex            lock;
  50         int                     adc_max;        /* number of ADC channels */
  51         char                    valid;
  52         unsigned long           last_updated;   /* In jiffies */
  53         s16                     temp[3];        /* Register values */
  54         u16                     in[4];
  55 };
  56
  57 static int ad7418_probe(struct i2c_client *client,
  58                         const struct i2c_device_id *id);
  59 static int ad7418_remove(struct i2c_client *client);
  60
  61 static const struct i2c_device_id ad7418_id[] = {
  62         { "ad7416", ad7416 },
  63         { "ad7417", ad7417 },
  64         { "ad7418", ad7418 },
  65         { }
  66 };
  67 MODULE_DEVICE_TABLE(i2c, ad7418_id);
  68
  69 static struct i2c_driver ad7418_driver = {
  70         .driver = {
  71                 .name   = "ad7418",
  72         },
  73         .probe          = ad7418_probe,
  74         .remove         = ad7418_remove,
  75         .id_table       = ad7418_id,
  76 };
  77
  78 /* All registers are word-sized, except for the configuration registers.
  79  * AD7418 uses a high-byte first convention. Do NOT use those functions to
  80  * access the configuration registers CONF and CONF2, as they are byte-sized.
  81  */
  82 static inline int ad7418_read(struct i2c_client *client, u8 reg)
  83 {
  84         return swab16(i2c_smbus_read_word_data(client, reg));
  85 }
  86
  87 static inline int ad7418_write(struct i2c_client *client, u8 reg, u16 value)
  88 {
  89         return i2c_smbus_write_word_data(client, reg, swab16(value));
  90 }
  91
  92 static void ad7418_init_client(struct i2c_client *client)
  93 {
  94         struct ad7418_data *data = i2c_get_clientdata(client);
  95
  96         int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
  97         if (reg < 0) {
  98                 dev_err(&client->dev, "cannot read configuration register\n");
  99         } else {
 100                 dev_info(&client->dev, "configuring for mode 1\n");
 101                 i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
 102
 103                 if (data->type == ad7417 || data->type == ad7418)
 104                         i2c_smbus_write_byte_data(client,
 105                                                 AD7418_REG_CONF2, 0x00);
 106         }
 107 }
 108
 109 static struct ad7418_data *ad7418_update_device(struct device *dev)
 110 {
 111         struct i2c_client *client = to_i2c_client(dev);
 112         struct ad7418_data *data = i2c_get_clientdata(client);
 113
 114         mutex_lock(&data->lock);
 115
 116         if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 117                 || !data->valid) {
 118                 u8 cfg;
 119                 int i, ch;
 120
 121                 /* read config register and clear channel bits */
 122                 cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
 123                 cfg &= 0x1F;
 124
 125                 i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
 126                                                 cfg | AD7418_CH_TEMP);
 127                 udelay(30);
 128
 129                 for (i = 0; i < 3; i++) {
 130                         data->temp[i] = ad7418_read(client, AD7418_REG_TEMP[i]);
 131                 }
 132
 133                 for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
 134                         i2c_smbus_write_byte_data(client,
 135                                         AD7418_REG_CONF,
 136                                         cfg | AD7418_REG_ADC_CH(ch));
 137
 138                         udelay(15);
 139                         data->in[data->adc_max - 1 - i] =
 140                                 ad7418_read(client, AD7418_REG_ADC);
 141                 }
 142
 143                 /* restore old configuration value */
 144                 ad7418_write(client, AD7418_REG_CONF, cfg);
 145
 146                 data->last_updated = jiffies;
 147                 data->valid = 1;
 148         }
 149
 150         mutex_unlock(&data->lock);
 151
 152         return data;
 153 }
 154
 155 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 156                         char *buf)
 157 {
 158         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 159         struct ad7418_data *data = ad7418_update_device(dev);
 160         return sprintf(buf, "%d\n",
 161                 LM75_TEMP_FROM_REG(data->temp[attr->index]));
 162 }
 163
 164 static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
 165                         char *buf)
 166 {
 167         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 168         struct ad7418_data *data = ad7418_update_device(dev);
 169
 170         return sprintf(buf, "%d\n",
 171                 ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
 172 }
 173
 174 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 175                         const char *buf, size_t count)
 176 {
 177         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 178         struct i2c_client *client = to_i2c_client(dev);
 179         struct ad7418_data *data = i2c_get_clientdata(client);
 180         long temp = simple_strtol(buf, NULL, 10);
 181
 182         mutex_lock(&data->lock);
 183         data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
 184         ad7418_write(client, AD7418_REG_TEMP[attr->index], data->temp[attr->index]);
 185         mutex_unlock(&data->lock);
 186         return count;
 187 }
 188
 189 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 190 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 191                                 show_temp, set_temp, 1);
 192 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 193                                 show_temp, set_temp, 2);
 194
 195 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
 196 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
 197 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
 198 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
 199
 200 static struct attribute *ad7416_attributes[] = {
 201         &sensor_dev_attr_temp1_max.dev_attr.attr,
 202         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 203         &sensor_dev_attr_temp1_input.dev_attr.attr,
 204         NULL
 205 };
 206
 207 static struct attribute *ad7417_attributes[] = {
 208         &sensor_dev_attr_temp1_max.dev_attr.attr,
 209         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 210         &sensor_dev_attr_temp1_input.dev_attr.attr,
 211         &sensor_dev_attr_in1_input.dev_attr.attr,
 212         &sensor_dev_attr_in2_input.dev_attr.attr,
 213         &sensor_dev_attr_in3_input.dev_attr.attr,
 214         &sensor_dev_attr_in4_input.dev_attr.attr,
 215         NULL
 216 };
 217
 218 static struct attribute *ad7418_attributes[] = {
 219         &sensor_dev_attr_temp1_max.dev_attr.attr,
 220         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 221         &sensor_dev_attr_temp1_input.dev_attr.attr,
 222         &sensor_dev_attr_in1_input.dev_attr.attr,
 223         NULL
 224 };
 225
 226 static int ad7418_probe(struct i2c_client *client,
 227                          const struct i2c_device_id *id)
 228 {
 229         struct i2c_adapter *adapter = client->adapter;
 230         struct ad7418_data *data;
 231         int err;
 232
 233         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 234                                         I2C_FUNC_SMBUS_WORD_DATA)) {
 235                 err = -EOPNOTSUPP;
 236                 goto exit;
 237         }
 238
 239         if (!(data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL))) {
 240                 err = -ENOMEM;
 241                 goto exit;
 242         }
 243
 244         i2c_set_clientdata(client, data);
 245
 246         mutex_init(&data->lock);
 247         data->type = id->driver_data;
 248
 249         switch (data->type) {
 250         case ad7416:
 251                 data->adc_max = 0;
 252                 data->attrs.attrs = ad7416_attributes;
 253                 break;
 254
 255         case ad7417:
 256                 data->adc_max = 4;
 257                 data->attrs.attrs = ad7417_attributes;
 258                 break;
 259
 260         case ad7418:
 261                 data->adc_max = 1;
 262                 data->attrs.attrs = ad7418_attributes;
 263                 break;
 264         }
 265
 266         dev_info(&client->dev, "%s chip found\n", client->name);
 267
 268         /* Initialize the AD7418 chip */
 269         ad7418_init_client(client);
 270
 271         /* Register sysfs hooks */
 272         if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
 273                 goto exit_free;
 274
 275         data->hwmon_dev = hwmon_device_register(&client->dev);
 276         if (IS_ERR(data->hwmon_dev)) {
 277                 err = PTR_ERR(data->hwmon_dev);
 278                 goto exit_remove;
 279         }
 280
 281         return 0;
 282
 283 exit_remove:
 284         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 285 exit_free:
 286         kfree(data);
 287 exit:
 288         return err;
 289 }
 290
 291 static int ad7418_remove(struct i2c_client *client)
 292 {
 293         struct ad7418_data *data = i2c_get_clientdata(client);
 294         hwmon_device_unregister(data->hwmon_dev);
 295         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 296         kfree(data);
 297         return 0;
 298 }
 299
 300 static int __init ad7418_init(void)
 301 {
 302         return i2c_add_driver(&ad7418_driver);
 303 }
 304
 305 static void __exit ad7418_exit(void)
 306 {
 307         i2c_del_driver(&ad7418_driver);
 308 }
 309
 310 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 311 MODULE_DESCRIPTION("AD7416/17/18 driver");
 312 MODULE_LICENSE("GPL");
 313 MODULE_VERSION(DRV_VERSION);
 314
 315 module_init(ad7418_init);
 316 module_exit(ad7418_exit);