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 "0.3"
  27
  28 /* Addresses to scan */
  29 static const unsigned short normal_i2c[] = { 0x28, I2C_CLIENT_END };
  30 /* Insmod parameters */
  31 I2C_CLIENT_INSMOD_3(ad7416, ad7417, ad7418);
  32
  33 /* AD7418 registers */
  34 #define AD7418_REG_TEMP_IN      0x00
  35 #define AD7418_REG_CONF         0x01
  36 #define AD7418_REG_TEMP_HYST    0x02
  37 #define AD7418_REG_TEMP_OS      0x03
  38 #define AD7418_REG_ADC          0x04
  39 #define AD7418_REG_CONF2        0x05
  40
  41 #define AD7418_REG_ADC_CH(x)    ((x) << 5)
  42 #define AD7418_CH_TEMP          AD7418_REG_ADC_CH(0)
  43
  44 static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
  45                                         AD7418_REG_TEMP_HYST,
  46                                         AD7418_REG_TEMP_OS };
  47
  48 struct ad7418_data {
  49         struct i2c_client       client;
  50         struct device           *hwmon_dev;
  51         struct attribute_group  attrs;
  52         enum chips              type;
  53         struct mutex            lock;
  54         int                     adc_max;        /* number of ADC channels */
  55         char                    valid;
  56         unsigned long           last_updated;   /* In jiffies */
  57         s16                     temp[3];        /* Register values */
  58         u16                     in[4];
  59 };
  60
  61 static int ad7418_attach_adapter(struct i2c_adapter *adapter);
  62 static int ad7418_detect(struct i2c_adapter *adapter, int address, int kind);
  63 static int ad7418_detach_client(struct i2c_client *client);
  64
  65 static struct i2c_driver ad7418_driver = {
  66         .driver = {
  67                 .name   = "ad7418",
  68         },
  69         .attach_adapter = ad7418_attach_adapter,
  70         .detach_client  = ad7418_detach_client,
  71 };
  72
  73 /* All registers are word-sized, except for the configuration registers.
  74  * AD7418 uses a high-byte first convention. Do NOT use those functions to
  75  * access the configuration registers CONF and CONF2, as they are byte-sized.
  76  */
  77 static inline int ad7418_read(struct i2c_client *client, u8 reg)
  78 {
  79         return swab16(i2c_smbus_read_word_data(client, reg));
  80 }
  81
  82 static inline int ad7418_write(struct i2c_client *client, u8 reg, u16 value)
  83 {
  84         return i2c_smbus_write_word_data(client, reg, swab16(value));
  85 }
  86
  87 static void ad7418_init_client(struct i2c_client *client)
  88 {
  89         struct ad7418_data *data = i2c_get_clientdata(client);
  90
  91         int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
  92         if (reg < 0) {
  93                 dev_err(&client->dev, "cannot read configuration register\n");
  94         } else {
  95                 dev_info(&client->dev, "configuring for mode 1\n");
  96                 i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
  97
  98                 if (data->type == ad7417 || data->type == ad7418)
  99                         i2c_smbus_write_byte_data(client,
 100                                                 AD7418_REG_CONF2, 0x00);
 101         }
 102 }
 103
 104 static struct ad7418_data *ad7418_update_device(struct device *dev)
 105 {
 106         struct i2c_client *client = to_i2c_client(dev);
 107         struct ad7418_data *data = i2c_get_clientdata(client);
 108
 109         mutex_lock(&data->lock);
 110
 111         if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 112                 || !data->valid) {
 113                 u8 cfg;
 114                 int i, ch;
 115
 116                 /* read config register and clear channel bits */
 117                 cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
 118                 cfg &= 0x1F;
 119
 120                 i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
 121                                                 cfg | AD7418_CH_TEMP);
 122                 udelay(30);
 123
 124                 for (i = 0; i < 3; i++) {
 125                         data->temp[i] = ad7418_read(client, AD7418_REG_TEMP[i]);
 126                 }
 127
 128                 for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
 129                         i2c_smbus_write_byte_data(client,
 130                                         AD7418_REG_CONF,
 131                                         cfg | AD7418_REG_ADC_CH(ch));
 132
 133                         udelay(15);
 134                         data->in[data->adc_max - 1 - i] =
 135                                 ad7418_read(client, AD7418_REG_ADC);
 136                 }
 137
 138                 /* restore old configuration value */
 139                 ad7418_write(client, AD7418_REG_CONF, cfg);
 140
 141                 data->last_updated = jiffies;
 142                 data->valid = 1;
 143         }
 144
 145         mutex_unlock(&data->lock);
 146
 147         return data;
 148 }
 149
 150 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 151                         char *buf)
 152 {
 153         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 154         struct ad7418_data *data = ad7418_update_device(dev);
 155         return sprintf(buf, "%d\n",
 156                 LM75_TEMP_FROM_REG(data->temp[attr->index]));
 157 }
 158
 159 static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
 160                         char *buf)
 161 {
 162         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 163         struct ad7418_data *data = ad7418_update_device(dev);
 164
 165         return sprintf(buf, "%d\n",
 166                 ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
 167 }
 168
 169 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 170                         const char *buf, size_t count)
 171 {
 172         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 173         struct i2c_client *client = to_i2c_client(dev);
 174         struct ad7418_data *data = i2c_get_clientdata(client);
 175         long temp = simple_strtol(buf, NULL, 10);
 176
 177         mutex_lock(&data->lock);
 178         data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
 179         ad7418_write(client, AD7418_REG_TEMP[attr->index], data->temp[attr->index]);
 180         mutex_unlock(&data->lock);
 181         return count;
 182 }
 183
 184 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 185 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 186                                 show_temp, set_temp, 1);
 187 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 188                                 show_temp, set_temp, 2);
 189
 190 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
 191 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
 192 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
 193 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
 194
 195 static int ad7418_attach_adapter(struct i2c_adapter *adapter)
 196 {
 197         if (!(adapter->class & I2C_CLASS_HWMON))
 198                 return 0;
 199         return i2c_probe(adapter, &addr_data, ad7418_detect);
 200 }
 201
 202 static struct attribute *ad7416_attributes[] = {
 203         &sensor_dev_attr_temp1_max.dev_attr.attr,
 204         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 205         &sensor_dev_attr_temp1_input.dev_attr.attr,
 206         NULL
 207 };
 208
 209 static struct attribute *ad7417_attributes[] = {
 210         &sensor_dev_attr_temp1_max.dev_attr.attr,
 211         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 212         &sensor_dev_attr_temp1_input.dev_attr.attr,
 213         &sensor_dev_attr_in1_input.dev_attr.attr,
 214         &sensor_dev_attr_in2_input.dev_attr.attr,
 215         &sensor_dev_attr_in3_input.dev_attr.attr,
 216         &sensor_dev_attr_in4_input.dev_attr.attr,
 217         NULL
 218 };
 219
 220 static struct attribute *ad7418_attributes[] = {
 221         &sensor_dev_attr_temp1_max.dev_attr.attr,
 222         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 223         &sensor_dev_attr_temp1_input.dev_attr.attr,
 224         &sensor_dev_attr_in1_input.dev_attr.attr,
 225         NULL
 226 };
 227
 228 static int ad7418_detect(struct i2c_adapter *adapter, int address, int kind)
 229 {
 230         struct i2c_client *client;
 231         struct ad7418_data *data;
 232         int err = 0;
 233
 234         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 235                                         I2C_FUNC_SMBUS_WORD_DATA))
 236                 goto exit;
 237
 238         if (!(data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL))) {
 239                 err = -ENOMEM;
 240                 goto exit;
 241         }
 242
 243         client = &data->client;
 244         client->addr = address;
 245         client->adapter = adapter;
 246         client->driver = &ad7418_driver;
 247
 248         i2c_set_clientdata(client, data);
 249
 250         mutex_init(&data->lock);
 251
 252         /* AD7418 has a curious behaviour on registers 6 and 7. They
 253          * both always read 0xC071 and are not documented on the datasheet.
 254          * We use them to detect the chip.
 255          */
 256         if (kind <= 0) {
 257                 int reg, reg6, reg7;
 258
 259                 /* the AD7416 lies within this address range, but I have
 260                  * no means to check.
 261                  */
 262                 if (address >= 0x48 && address <= 0x4f) {
 263                         /* XXX add tests for AD7416 here */
 264                         /* data->type = ad7416; */
 265                 }
 266                 /* here we might have AD7417 or AD7418 */
 267                 else if (address >= 0x28 && address <= 0x2f) {
 268                         reg6 = i2c_smbus_read_word_data(client, 0x06);
 269                         reg7 = i2c_smbus_read_word_data(client, 0x07);
 270
 271                         if (address == 0x28 && reg6 == 0xC071 && reg7 == 0xC071)
 272                                 data->type = ad7418;
 273
 274                         /* XXX add tests for AD7417 here */
 275
 276
 277                         /* both AD7417 and AD7418 have bits 0-5 of
 278                          * the CONF2 register at 0
 279                          */
 280                         reg = i2c_smbus_read_byte_data(client,
 281                                                         AD7418_REG_CONF2);
 282                         if (reg & 0x3F)
 283                                 data->type = any_chip; /* detection failed */
 284                 }
 285         } else {
 286                 dev_dbg(&adapter->dev, "detection forced\n");
 287         }
 288
 289         if (kind > 0)
 290                 data->type = kind;
 291         else if (kind < 0 && data->type == any_chip) {
 292                 err = -ENODEV;
 293                 goto exit_free;
 294         }
 295
 296         switch (data->type) {
 297         case any_chip:
 298         case ad7416:
 299                 data->adc_max = 0;
 300                 data->attrs.attrs = ad7416_attributes;
 301                 strlcpy(client->name, "ad7416", I2C_NAME_SIZE);
 302                 break;
 303
 304         case ad7417:
 305                 data->adc_max = 4;
 306                 data->attrs.attrs = ad7417_attributes;
 307                 strlcpy(client->name, "ad7417", I2C_NAME_SIZE);
 308                 break;
 309
 310         case ad7418:
 311                 data->adc_max = 1;
 312                 data->attrs.attrs = ad7418_attributes;
 313                 strlcpy(client->name, "ad7418", I2C_NAME_SIZE);
 314                 break;
 315         }
 316
 317         if ((err = i2c_attach_client(client)))
 318                 goto exit_free;
 319
 320         dev_info(&client->dev, "%s chip found\n", client->name);
 321
 322         /* Initialize the AD7418 chip */
 323         ad7418_init_client(client);
 324
 325         /* Register sysfs hooks */
 326         if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
 327                 goto exit_detach;
 328
 329         data->hwmon_dev = hwmon_device_register(&client->dev);
 330         if (IS_ERR(data->hwmon_dev)) {
 331                 err = PTR_ERR(data->hwmon_dev);
 332                 goto exit_remove;
 333         }
 334
 335         return 0;
 336
 337 exit_remove:
 338         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 339 exit_detach:
 340         i2c_detach_client(client);
 341 exit_free:
 342         kfree(data);
 343 exit:
 344         return err;
 345 }
 346
 347 static int ad7418_detach_client(struct i2c_client *client)
 348 {
 349         struct ad7418_data *data = i2c_get_clientdata(client);
 350         hwmon_device_unregister(data->hwmon_dev);
 351         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 352         i2c_detach_client(client);
 353         kfree(data);
 354         return 0;
 355 }
 356
 357 static int __init ad7418_init(void)
 358 {
 359         return i2c_add_driver(&ad7418_driver);
 360 }
 361
 362 static void __exit ad7418_exit(void)
 363 {
 364         i2c_del_driver(&ad7418_driver);
 365 }
 366
 367 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 368 MODULE_DESCRIPTION("AD7416/17/18 driver");
 369 MODULE_LICENSE("GPL");
 370 MODULE_VERSION(DRV_VERSION);
 371
 372 module_init(ad7418_init);
 373 module_exit(ad7418_exit);