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;
 171         int ret = kstrtol(buf, 10, &temp);
 172
 173         if (ret < 0)
 174                 return ret;
 175
 176         mutex_lock(&data->lock);
 177         data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
 178         i2c_smbus_write_word_swapped(client,
 179                                      AD7418_REG_TEMP[attr->index],
 180                                      data->temp[attr->index]);
 181         mutex_unlock(&data->lock);
 182         return count;
 183 }
 184
 185 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 186 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 187                                 show_temp, set_temp, 1);
 188 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 189                                 show_temp, set_temp, 2);
 190
 191 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
 192 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
 193 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
 194 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
 195
 196 static struct attribute *ad7416_attributes[] = {
 197         &sensor_dev_attr_temp1_max.dev_attr.attr,
 198         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 199         &sensor_dev_attr_temp1_input.dev_attr.attr,
 200         NULL
 201 };
 202
 203 static struct attribute *ad7417_attributes[] = {
 204         &sensor_dev_attr_temp1_max.dev_attr.attr,
 205         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 206         &sensor_dev_attr_temp1_input.dev_attr.attr,
 207         &sensor_dev_attr_in1_input.dev_attr.attr,
 208         &sensor_dev_attr_in2_input.dev_attr.attr,
 209         &sensor_dev_attr_in3_input.dev_attr.attr,
 210         &sensor_dev_attr_in4_input.dev_attr.attr,
 211         NULL
 212 };
 213
 214 static struct attribute *ad7418_attributes[] = {
 215         &sensor_dev_attr_temp1_max.dev_attr.attr,
 216         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 217         &sensor_dev_attr_temp1_input.dev_attr.attr,
 218         &sensor_dev_attr_in1_input.dev_attr.attr,
 219         NULL
 220 };
 221
 222 static int ad7418_probe(struct i2c_client *client,
 223                          const struct i2c_device_id *id)
 224 {
 225         struct i2c_adapter *adapter = client->adapter;
 226         struct ad7418_data *data;
 227         int err;
 228
 229         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 230                                         I2C_FUNC_SMBUS_WORD_DATA)) {
 231                 err = -EOPNOTSUPP;
 232                 goto exit;
 233         }
 234
 235         data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL);
 236         if (!data) {
 237                 err = -ENOMEM;
 238                 goto exit;
 239         }
 240
 241         i2c_set_clientdata(client, data);
 242
 243         mutex_init(&data->lock);
 244         data->type = id->driver_data;
 245
 246         switch (data->type) {
 247         case ad7416:
 248                 data->adc_max = 0;
 249                 data->attrs.attrs = ad7416_attributes;
 250                 break;
 251
 252         case ad7417:
 253                 data->adc_max = 4;
 254                 data->attrs.attrs = ad7417_attributes;
 255                 break;
 256
 257         case ad7418:
 258                 data->adc_max = 1;
 259                 data->attrs.attrs = ad7418_attributes;
 260                 break;
 261         }
 262
 263         dev_info(&client->dev, "%s chip found\n", client->name);
 264
 265         /* Initialize the AD7418 chip */
 266         ad7418_init_client(client);
 267
 268         /* Register sysfs hooks */
 269         err = sysfs_create_group(&client->dev.kobj, &data->attrs);
 270         if (err)
 271                 goto exit_free;
 272
 273         data->hwmon_dev = hwmon_device_register(&client->dev);
 274         if (IS_ERR(data->hwmon_dev)) {
 275                 err = PTR_ERR(data->hwmon_dev);
 276                 goto exit_remove;
 277         }
 278
 279         return 0;
 280
 281 exit_remove:
 282         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 283 exit_free:
 284         kfree(data);
 285 exit:
 286         return err;
 287 }
 288
 289 static int ad7418_remove(struct i2c_client *client)
 290 {
 291         struct ad7418_data *data = i2c_get_clientdata(client);
 292         hwmon_device_unregister(data->hwmon_dev);
 293         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 294         kfree(data);
 295         return 0;
 296 }
 297
 298 module_i2c_driver(ad7418_driver);
 299
 300 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 301 MODULE_DESCRIPTION("AD7416/17/18 driver");
 302 MODULE_LICENSE("GPL");
 303 MODULE_VERSION(DRV_VERSION);