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 i2c_client       *client;
  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
  57 static struct ad7418_data *ad7418_update_device(struct device *dev)
  58 {
  59         struct ad7418_data *data = dev_get_drvdata(dev);
  60         struct i2c_client *client = data->client;
  61
  62         mutex_lock(&data->lock);
  63
  64         if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
  65                 || !data->valid) {
  66                 u8 cfg;
  67                 int i, ch;
  68
  69                 /* read config register and clear channel bits */
  70                 cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
  71                 cfg &= 0x1F;
  72
  73                 i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
  74                                                 cfg | AD7418_CH_TEMP);
  75                 udelay(30);
  76
  77                 for (i = 0; i < 3; i++) {
  78                         data->temp[i] =
  79                                 i2c_smbus_read_word_swapped(client,
  80                                                 AD7418_REG_TEMP[i]);
  81                 }
  82
  83                 for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
  84                         i2c_smbus_write_byte_data(client,
  85                                         AD7418_REG_CONF,
  86                                         cfg | AD7418_REG_ADC_CH(ch));
  87
  88                         udelay(15);
  89                         data->in[data->adc_max - 1 - i] =
  90                                 i2c_smbus_read_word_swapped(client,
  91                                                 AD7418_REG_ADC);
  92                 }
  93
  94                 /* restore old configuration value */
  95                 i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, cfg);
  96
  97                 data->last_updated = jiffies;
  98                 data->valid = 1;
  99         }
 100
 101         mutex_unlock(&data->lock);
 102
 103         return data;
 104 }
 105
 106 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 107                         char *buf)
 108 {
 109         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 110         struct ad7418_data *data = ad7418_update_device(dev);
 111         return sprintf(buf, "%d\n",
 112                 LM75_TEMP_FROM_REG(data->temp[attr->index]));
 113 }
 114
 115 static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
 116                         char *buf)
 117 {
 118         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 119         struct ad7418_data *data = ad7418_update_device(dev);
 120
 121         return sprintf(buf, "%d\n",
 122                 ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
 123 }
 124
 125 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 126                         const char *buf, size_t count)
 127 {
 128         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 129         struct ad7418_data *data = dev_get_drvdata(dev);
 130         struct i2c_client *client = data->client;
 131         long temp;
 132         int ret = kstrtol(buf, 10, &temp);
 133
 134         if (ret < 0)
 135                 return ret;
 136
 137         mutex_lock(&data->lock);
 138         data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
 139         i2c_smbus_write_word_swapped(client,
 140                                      AD7418_REG_TEMP[attr->index],
 141                                      data->temp[attr->index]);
 142         mutex_unlock(&data->lock);
 143         return count;
 144 }
 145
 146 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 147 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 148                                 show_temp, set_temp, 1);
 149 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 150                                 show_temp, set_temp, 2);
 151
 152 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
 153 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
 154 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
 155 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
 156
 157 static struct attribute *ad7416_attrs[] = {
 158         &sensor_dev_attr_temp1_max.dev_attr.attr,
 159         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 160         &sensor_dev_attr_temp1_input.dev_attr.attr,
 161         NULL
 162 };
 163 ATTRIBUTE_GROUPS(ad7416);
 164
 165 static struct attribute *ad7417_attrs[] = {
 166         &sensor_dev_attr_temp1_max.dev_attr.attr,
 167         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 168         &sensor_dev_attr_temp1_input.dev_attr.attr,
 169         &sensor_dev_attr_in1_input.dev_attr.attr,
 170         &sensor_dev_attr_in2_input.dev_attr.attr,
 171         &sensor_dev_attr_in3_input.dev_attr.attr,
 172         &sensor_dev_attr_in4_input.dev_attr.attr,
 173         NULL
 174 };
 175 ATTRIBUTE_GROUPS(ad7417);
 176
 177 static struct attribute *ad7418_attrs[] = {
 178         &sensor_dev_attr_temp1_max.dev_attr.attr,
 179         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 180         &sensor_dev_attr_temp1_input.dev_attr.attr,
 181         &sensor_dev_attr_in1_input.dev_attr.attr,
 182         NULL
 183 };
 184 ATTRIBUTE_GROUPS(ad7418);
 185
 186 static void ad7418_init_client(struct i2c_client *client)
 187 {
 188         struct ad7418_data *data = i2c_get_clientdata(client);
 189
 190         int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
 191         if (reg < 0) {
 192                 dev_err(&client->dev, "cannot read configuration register\n");
 193         } else {
 194                 dev_info(&client->dev, "configuring for mode 1\n");
 195                 i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
 196
 197                 if (data->type == ad7417 || data->type == ad7418)
 198                         i2c_smbus_write_byte_data(client,
 199                                                 AD7418_REG_CONF2, 0x00);
 200         }
 201 }
 202
 203 static int ad7418_probe(struct i2c_client *client,
 204                          const struct i2c_device_id *id)
 205 {
 206         struct device *dev = &client->dev;
 207         struct i2c_adapter *adapter = client->adapter;
 208         struct ad7418_data *data;
 209         struct device *hwmon_dev;
 210         const struct attribute_group **attr_groups = NULL;
 211
 212         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 213                                         I2C_FUNC_SMBUS_WORD_DATA))
 214                 return -EOPNOTSUPP;
 215
 216         data = devm_kzalloc(dev, sizeof(struct ad7418_data), GFP_KERNEL);
 217         if (!data)
 218                 return -ENOMEM;
 219
 220         i2c_set_clientdata(client, data);
 221
 222         mutex_init(&data->lock);
 223         data->client = client;
 224         data->type = id->driver_data;
 225
 226         switch (data->type) {
 227         case ad7416:
 228                 data->adc_max = 0;
 229                 attr_groups = ad7416_groups;
 230                 break;
 231
 232         case ad7417:
 233                 data->adc_max = 4;
 234                 attr_groups = ad7417_groups;
 235                 break;
 236
 237         case ad7418:
 238                 data->adc_max = 1;
 239                 attr_groups = ad7418_groups;
 240                 break;
 241         }
 242
 243         dev_info(dev, "%s chip found\n", client->name);
 244
 245         /* Initialize the AD7418 chip */
 246         ad7418_init_client(client);
 247
 248         hwmon_dev = devm_hwmon_device_register_with_groups(dev,
 249                                                            client->name,
 250                                                            data, attr_groups);
 251         return PTR_ERR_OR_ZERO(hwmon_dev);
 252 }
 253
 254 static const struct i2c_device_id ad7418_id[] = {
 255         { "ad7416", ad7416 },
 256         { "ad7417", ad7417 },
 257         { "ad7418", ad7418 },
 258         { }
 259 };
 260 MODULE_DEVICE_TABLE(i2c, ad7418_id);
 261
 262 static struct i2c_driver ad7418_driver = {
 263         .driver = {
 264                 .name   = "ad7418",
 265         },
 266         .probe          = ad7418_probe,
 267         .id_table       = ad7418_id,
 268 };
 269
 270 module_i2c_driver(ad7418_driver);
 271
 272 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 273 MODULE_DESCRIPTION("AD7416/17/18 driver");
 274 MODULE_LICENSE("GPL");
 275 MODULE_VERSION(DRV_VERSION);