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#include <linux/slab.h>
  24
  25#include "lm75.h"
  26
  27#define DRV_VERSION "0.4"
  28
  29enum 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
  42static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
  43                                        AD7418_REG_TEMP_HYST,
  44                                        AD7418_REG_TEMP_OS };
  45
  46struct 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
  58static int ad7418_probe(struct i2c_client *client,
  59                        const struct i2c_device_id *id);
  60static int ad7418_remove(struct i2c_client *client);
  61
  62static const struct i2c_device_id ad7418_id[] = {
  63        { "ad7416", ad7416 },
  64        { "ad7417", ad7417 },
  65        { "ad7418", ad7418 },
  66        { }
  67};
  68MODULE_DEVICE_TABLE(i2c, ad7418_id);
  69
  70static 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
  79static 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
  96static 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
 145static 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
 154static 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
 164static 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
 185static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 186static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 187                                show_temp, set_temp, 1);
 188static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 189                                show_temp, set_temp, 2);
 190
 191static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
 192static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
 193static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
 194static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
 195
 196static 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
 203static 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
 214static 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
 222static 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                return -EOPNOTSUPP;
 232
 233        data = devm_kzalloc(&client->dev, sizeof(struct ad7418_data),
 234                            GFP_KERNEL);
 235        if (!data)
 236                return -ENOMEM;
 237
 238        i2c_set_clientdata(client, data);
 239
 240        mutex_init(&data->lock);
 241        data->type = id->driver_data;
 242
 243        switch (data->type) {
 244        case ad7416:
 245                data->adc_max = 0;
 246                data->attrs.attrs = ad7416_attributes;
 247                break;
 248
 249        case ad7417:
 250                data->adc_max = 4;
 251                data->attrs.attrs = ad7417_attributes;
 252                break;
 253
 254        case ad7418:
 255                data->adc_max = 1;
 256                data->attrs.attrs = ad7418_attributes;
 257                break;
 258        }
 259
 260        dev_info(&client->dev, "%s chip found\n", client->name);
 261
 262        /* Initialize the AD7418 chip */
 263        ad7418_init_client(client);
 264
 265        /* Register sysfs hooks */
 266        err = sysfs_create_group(&client->dev.kobj, &data->attrs);
 267        if (err)
 268                return err;
 269
 270        data->hwmon_dev = hwmon_device_register(&client->dev);
 271        if (IS_ERR(data->hwmon_dev)) {
 272                err = PTR_ERR(data->hwmon_dev);
 273                goto exit_remove;
 274        }
 275
 276        return 0;
 277
 278exit_remove:
 279        sysfs_remove_group(&client->dev.kobj, &data->attrs);
 280        return err;
 281}
 282
 283static 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        return 0;
 289}
 290
 291module_i2c_driver(ad7418_driver);
 292
 293MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 294MODULE_DESCRIPTION("AD7416/17/18 driver");
 295MODULE_LICENSE("GPL");
 296MODULE_VERSION(DRV_VERSION);
 297
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