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