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 static void ad7418_init_client(struct i2c_client *client)
  80 {
  81         struct ad7418_data *data = i2c_get_clientdata(client);
  82
  83         int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
  84         if (reg < 0) {
  85                 dev_err(&client->dev, "cannot read configuration register\n");
  86         } else {
  87                 dev_info(&client->dev, "configuring for mode 1\n");
  88                 i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
  89
  90                 if (data->type == ad7417 || data->type == ad7418)
  91                         i2c_smbus_write_byte_data(client,
  92                                                 AD7418_REG_CONF2, 0x00);
  93         }
  94 }
  95
  96 static struct ad7418_data *ad7418_update_device(struct device *dev)
  97 {
  98         struct i2c_client *client = to_i2c_client(dev);
  99         struct ad7418_data *data = i2c_get_clientdata(client);
 100
 101         mutex_lock(&data->lock);
 102
 103         if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 104                 || !data->valid) {
 105                 u8 cfg;
 106                 int i, ch;
 107
 108                 /* read config register and clear channel bits */
 109                 cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
 110                 cfg &= 0x1F;
 111
 112                 i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
 113                                                 cfg | AD7418_CH_TEMP);
 114                 udelay(30);
 115
 116                 for (i = 0; i < 3; i++) {
 117                         data->temp[i] =
 118                                 i2c_smbus_read_word_swapped(client,
 119                                                 AD7418_REG_TEMP[i]);
 120                 }
 121
 122                 for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
 123                         i2c_smbus_write_byte_data(client,
 124                                         AD7418_REG_CONF,
 125                                         cfg | AD7418_REG_ADC_CH(ch));
 126
 127                         udelay(15);
 128                         data->in[data->adc_max - 1 - i] =
 129                                 i2c_smbus_read_word_swapped(client,
 130                                                 AD7418_REG_ADC);
 131                 }
 132
 133                 /* restore old configuration value */
 134                 i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, cfg);
 135
 136                 data->last_updated = jiffies;
 137                 data->valid = 1;
 138         }
 139
 140         mutex_unlock(&data->lock);
 141
 142         return data;
 143 }
 144
 145 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 146                         char *buf)
 147 {
 148         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 149         struct ad7418_data *data = ad7418_update_device(dev);
 150         return sprintf(buf, "%d\n",
 151                 LM75_TEMP_FROM_REG(data->temp[attr->index]));
 152 }
 153
 154 static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
 155                         char *buf)
 156 {
 157         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 158         struct ad7418_data *data = ad7418_update_device(dev);
 159
 160         return sprintf(buf, "%d\n",
 161                 ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
 162 }
 163
 164 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 165                         const char *buf, size_t count)
 166 {
 167         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 168         struct i2c_client *client = to_i2c_client(dev);
 169         struct ad7418_data *data = i2c_get_clientdata(client);
 170         long temp = simple_strtol(buf, NULL, 10);
 171
 172         mutex_lock(&data->lock);
 173         data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
 174         i2c_smbus_write_word_swapped(client,
 175                                      AD7418_REG_TEMP[attr->index],
 176                                      data->temp[attr->index]);
 177         mutex_unlock(&data->lock);
 178         return count;
 179 }
 180
 181 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 182 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 183                                 show_temp, set_temp, 1);
 184 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 185                                 show_temp, set_temp, 2);
 186
 187 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
 188 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
 189 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
 190 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
 191
 192 static struct attribute *ad7416_attributes[] = {
 193         &sensor_dev_attr_temp1_max.dev_attr.attr,
 194         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 195         &sensor_dev_attr_temp1_input.dev_attr.attr,
 196         NULL
 197 };
 198
 199 static struct attribute *ad7417_attributes[] = {
 200         &sensor_dev_attr_temp1_max.dev_attr.attr,
 201         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 202         &sensor_dev_attr_temp1_input.dev_attr.attr,
 203         &sensor_dev_attr_in1_input.dev_attr.attr,
 204         &sensor_dev_attr_in2_input.dev_attr.attr,
 205         &sensor_dev_attr_in3_input.dev_attr.attr,
 206         &sensor_dev_attr_in4_input.dev_attr.attr,
 207         NULL
 208 };
 209
 210 static struct attribute *ad7418_attributes[] = {
 211         &sensor_dev_attr_temp1_max.dev_attr.attr,
 212         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 213         &sensor_dev_attr_temp1_input.dev_attr.attr,
 214         &sensor_dev_attr_in1_input.dev_attr.attr,
 215         NULL
 216 };
 217
 218 static int ad7418_probe(struct i2c_client *client,
 219                          const struct i2c_device_id *id)
 220 {
 221         struct i2c_adapter *adapter = client->adapter;
 222         struct ad7418_data *data;
 223         int err;
 224
 225         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 226                                         I2C_FUNC_SMBUS_WORD_DATA)) {
 227                 err = -EOPNOTSUPP;
 228                 goto exit;
 229         }
 230
 231         if (!(data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL))) {
 232                 err = -ENOMEM;
 233                 goto exit;
 234         }
 235
 236         i2c_set_clientdata(client, data);
 237
 238         mutex_init(&data->lock);
 239         data->type = id->driver_data;
 240
 241         switch (data->type) {
 242         case ad7416:
 243                 data->adc_max = 0;
 244                 data->attrs.attrs = ad7416_attributes;
 245                 break;
 246
 247         case ad7417:
 248                 data->adc_max = 4;
 249                 data->attrs.attrs = ad7417_attributes;
 250                 break;
 251
 252         case ad7418:
 253                 data->adc_max = 1;
 254                 data->attrs.attrs = ad7418_attributes;
 255                 break;
 256         }
 257
 258         dev_info(&client->dev, "%s chip found\n", client->name);
 259
 260         /* Initialize the AD7418 chip */
 261         ad7418_init_client(client);
 262
 263         /* Register sysfs hooks */
 264         if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
 265                 goto exit_free;
 266
 267         data->hwmon_dev = hwmon_device_register(&client->dev);
 268         if (IS_ERR(data->hwmon_dev)) {
 269                 err = PTR_ERR(data->hwmon_dev);
 270                 goto exit_remove;
 271         }
 272
 273         return 0;
 274
 275 exit_remove:
 276         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 277 exit_free:
 278         kfree(data);
 279 exit:
 280         return err;
 281 }
 282
 283 static int ad7418_remove(struct i2c_client *client)
 284 {
 285         struct ad7418_data *data = i2c_get_clientdata(client);
 286         hwmon_device_unregister(data->hwmon_dev);
 287         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 288         kfree(data);
 289         return 0;
 290 }
 291
 292 static int __init ad7418_init(void)
 293 {
 294         return i2c_add_driver(&ad7418_driver);
 295 }
 296
 297 static void __exit ad7418_exit(void)
 298 {
 299         i2c_del_driver(&ad7418_driver);
 300 }
 301
 302 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 303 MODULE_DESCRIPTION("AD7416/17/18 driver");
 304 MODULE_LICENSE("GPL");
 305 MODULE_VERSION(DRV_VERSION);
 306
 307 module_init(ad7418_init);
 308 module_exit(ad7418_exit);