linux/drivers/hwmon/ad7418.c
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   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
  28enum 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
  41static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
  42                                        AD7418_REG_TEMP_HYST,
  43                                        AD7418_REG_TEMP_OS };
  44
  45struct 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
  57static int ad7418_probe(struct i2c_client *client,
  58                        const struct i2c_device_id *id);
  59static int ad7418_remove(struct i2c_client *client);
  60
  61static const struct i2c_device_id ad7418_id[] = {
  62        { "ad7416", ad7416 },
  63        { "ad7417", ad7417 },
  64        { "ad7418", ad7418 },
  65        { }
  66};
  67MODULE_DEVICE_TABLE(i2c, ad7418_id);
  68
  69static 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 */
  82static inline int ad7418_read(struct i2c_client *client, u8 reg)
  83{
  84        return swab16(i2c_smbus_read_word_data(client, reg));
  85}
  86
  87static 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
  92static 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
 109static 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
 155static 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
 164static 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
 174static 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
 189static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 190static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 191                                show_temp, set_temp, 1);
 192static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 193                                show_temp, set_temp, 2);
 194
 195static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
 196static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
 197static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
 198static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
 199
 200static 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
 207static 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
 218static 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
 226static 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
 283exit_remove:
 284        sysfs_remove_group(&client->dev.kobj, &data->attrs);
 285exit_free:
 286        kfree(data);
 287exit:
 288        return err;
 289}
 290
 291static 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
 300static int __init ad7418_init(void)
 301{
 302        return i2c_add_driver(&ad7418_driver);
 303}
 304
 305static void __exit ad7418_exit(void)
 306{
 307        i2c_del_driver(&ad7418_driver);
 308}
 309
 310MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 311MODULE_DESCRIPTION("AD7416/17/18 driver");
 312MODULE_LICENSE("GPL");
 313MODULE_VERSION(DRV_VERSION);
 314
 315module_init(ad7418_init);
 316module_exit(ad7418_exit);
 317
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