drivers/hwmon/ds1621.c

   1 /*
   2     ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
   3              monitoring
   4     Christian W. Zuckschwerdt  <zany@triq.net>  2000-11-23
   5     based on lm75.c by Frodo Looijaard <frodol@dds.nl>
   6     Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
   7     the help of Jean Delvare <khali@linux-fr.org>
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17     GNU General Public License for more details.
  18
  19     You should have received a copy of the GNU General Public License
  20     along with this program; if not, write to the Free Software
  21     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/jiffies.h>
  28 #include <linux/i2c.h>
  29 #include <linux/hwmon.h>
  30 #include <linux/hwmon-sysfs.h>
  31 #include <linux/err.h>
  32 #include <linux/mutex.h>
  33 #include <linux/sysfs.h>
  34 #include "lm75.h"
  35
  36 /* Addresses to scan */
  37 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
  38                                         0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
  39
  40 /* Insmod parameters */
  41 I2C_CLIENT_INSMOD_1(ds1621);
  42 static int polarity = -1;
  43 module_param(polarity, int, 0);
  44 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
  45
  46 /* Many DS1621 constants specified below */
  47 /* Config register used for detection         */
  48 /*  7    6    5    4    3    2    1    0      */
  49 /* |Done|THF |TLF |NVB | X  | X  |POL |1SHOT| */
  50 #define DS1621_REG_CONFIG_NVB           0x10
  51 #define DS1621_REG_CONFIG_POLARITY      0x02
  52 #define DS1621_REG_CONFIG_1SHOT         0x01
  53 #define DS1621_REG_CONFIG_DONE          0x80
  54
  55 /* The DS1621 registers */
  56 static const u8 DS1621_REG_TEMP[3] = {
  57         0xAA,           /* input, word, RO */
  58         0xA2,           /* min, word, RW */
  59         0xA1,           /* max, word, RW */
  60 };
  61 #define DS1621_REG_CONF                 0xAC /* byte, RW */
  62 #define DS1621_COM_START                0xEE /* no data */
  63 #define DS1621_COM_STOP                 0x22 /* no data */
  64
  65 /* The DS1621 configuration register */
  66 #define DS1621_ALARM_TEMP_HIGH          0x40
  67 #define DS1621_ALARM_TEMP_LOW           0x20
  68
  69 /* Conversions */
  70 #define ALARMS_FROM_REG(val) ((val) & \
  71                               (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
  72
  73 /* Each client has this additional data */
  74 struct ds1621_data {
  75         struct device *hwmon_dev;
  76         struct mutex update_lock;
  77         char valid;                     /* !=0 if following fields are valid */
  78         unsigned long last_updated;     /* In jiffies */
  79
  80         u16 temp[3];                    /* Register values, word */
  81         u8 conf;                        /* Register encoding, combined */
  82 };
  83
  84 /* Temperature registers are word-sized.
  85    DS1621 uses a high-byte first convention, which is exactly opposite to
  86    the SMBus standard. */
  87 static int ds1621_read_temp(struct i2c_client *client, u8 reg)
  88 {
  89         int ret;
  90
  91         ret = i2c_smbus_read_word_data(client, reg);
  92         if (ret < 0)
  93                 return ret;
  94         return swab16(ret);
  95 }
  96
  97 static int ds1621_write_temp(struct i2c_client *client, u8 reg, u16 value)
  98 {
  99         return i2c_smbus_write_word_data(client, reg, swab16(value));
 100 }
 101
 102 static void ds1621_init_client(struct i2c_client *client)
 103 {
 104         u8 conf, new_conf;
 105
 106         new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
 107         /* switch to continuous conversion mode */
 108         new_conf &= ~DS1621_REG_CONFIG_1SHOT;
 109
 110         /* setup output polarity */
 111         if (polarity == 0)
 112                 new_conf &= ~DS1621_REG_CONFIG_POLARITY;
 113         else if (polarity == 1)
 114                 new_conf |= DS1621_REG_CONFIG_POLARITY;
 115
 116         if (conf != new_conf)
 117                 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf);
 118
 119         /* start conversion */
 120         i2c_smbus_write_byte(client, DS1621_COM_START);
 121 }
 122
 123 static struct ds1621_data *ds1621_update_client(struct device *dev)
 124 {
 125         struct i2c_client *client = to_i2c_client(dev);
 126         struct ds1621_data *data = i2c_get_clientdata(client);
 127         u8 new_conf;
 128
 129         mutex_lock(&data->update_lock);
 130
 131         if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 132             || !data->valid) {
 133                 int i;
 134
 135                 dev_dbg(&client->dev, "Starting ds1621 update\n");
 136
 137                 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
 138
 139                 for (i = 0; i < ARRAY_SIZE(data->temp); i++)
 140                         data->temp[i] = ds1621_read_temp(client,
 141                                                          DS1621_REG_TEMP[i]);
 142
 143                 /* reset alarms if necessary */
 144                 new_conf = data->conf;
 145                 if (data->temp[0] > data->temp[1])      /* input > min */
 146                         new_conf &= ~DS1621_ALARM_TEMP_LOW;
 147                 if (data->temp[0] < data->temp[2])      /* input < max */
 148                         new_conf &= ~DS1621_ALARM_TEMP_HIGH;
 149                 if (data->conf != new_conf)
 150                         i2c_smbus_write_byte_data(client, DS1621_REG_CONF,
 151                                                   new_conf);
 152
 153                 data->last_updated = jiffies;
 154                 data->valid = 1;
 155         }
 156
 157         mutex_unlock(&data->update_lock);
 158
 159         return data;
 160 }
 161
 162 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
 163                          char *buf)
 164 {
 165         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 166         struct ds1621_data *data = ds1621_update_client(dev);
 167         return sprintf(buf, "%d\n",
 168                        LM75_TEMP_FROM_REG(data->temp[attr->index]));
 169 }
 170
 171 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
 172                         const char *buf, size_t count)
 173 {
 174         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 175         struct i2c_client *client = to_i2c_client(dev);
 176         struct ds1621_data *data = i2c_get_clientdata(client);
 177         u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10));
 178
 179         mutex_lock(&data->update_lock);
 180         data->temp[attr->index] = val;
 181         ds1621_write_temp(client, DS1621_REG_TEMP[attr->index],
 182                           data->temp[attr->index]);
 183         mutex_unlock(&data->update_lock);
 184         return count;
 185 }
 186
 187 static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
 188                            char *buf)
 189 {
 190         struct ds1621_data *data = ds1621_update_client(dev);
 191         return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
 192 }
 193
 194 static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
 195                           char *buf)
 196 {
 197         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 198         struct ds1621_data *data = ds1621_update_client(dev);
 199         return sprintf(buf, "%d\n", !!(data->conf & attr->index));
 200 }
 201
 202 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 203 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 204 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
 205 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
 206 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 207                 DS1621_ALARM_TEMP_LOW);
 208 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 209                 DS1621_ALARM_TEMP_HIGH);
 210
 211 static struct attribute *ds1621_attributes[] = {
 212         &sensor_dev_attr_temp1_input.dev_attr.attr,
 213         &sensor_dev_attr_temp1_min.dev_attr.attr,
 214         &sensor_dev_attr_temp1_max.dev_attr.attr,
 215         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 216         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 217         &dev_attr_alarms.attr,
 218         NULL
 219 };
 220
 221 static const struct attribute_group ds1621_group = {
 222         .attrs = ds1621_attributes,
 223 };
 224
 225
 226 /* Return 0 if detection is successful, -ENODEV otherwise */
 227 static int ds1621_detect(struct i2c_client *client, int kind,
 228                          struct i2c_board_info *info)
 229 {
 230         struct i2c_adapter *adapter = client->adapter;
 231         int conf, temp;
 232         int i;
 233
 234         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
 235                                      | I2C_FUNC_SMBUS_WORD_DATA
 236                                      | I2C_FUNC_SMBUS_WRITE_BYTE))
 237                 return -ENODEV;
 238
 239         /* Now, we do the remaining detection. It is lousy. */
 240         /* The NVB bit should be low if no EEPROM write has been  requested
 241            during the latest 10ms, which is highly improbable in our case. */
 242         conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
 243         if (conf < 0 || conf & DS1621_REG_CONFIG_NVB)
 244                 return -ENODEV;
 245         /* The 7 lowest bits of a temperature should always be 0. */
 246         for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) {
 247                 temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]);
 248                 if (temp < 0 || (temp & 0x7f00))
 249                         return -ENODEV;
 250         }
 251
 252         strlcpy(info->type, "ds1621", I2C_NAME_SIZE);
 253
 254         return 0;
 255 }
 256
 257 static int ds1621_probe(struct i2c_client *client,
 258                         const struct i2c_device_id *id)
 259 {
 260         struct ds1621_data *data;
 261         int err;
 262
 263         data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL);
 264         if (!data) {
 265                 err = -ENOMEM;
 266                 goto exit;
 267         }
 268
 269         i2c_set_clientdata(client, data);
 270         mutex_init(&data->update_lock);
 271
 272         /* Initialize the DS1621 chip */
 273         ds1621_init_client(client);
 274
 275         /* Register sysfs hooks */
 276         if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group)))
 277                 goto exit_free;
 278
 279         data->hwmon_dev = hwmon_device_register(&client->dev);
 280         if (IS_ERR(data->hwmon_dev)) {
 281                 err = PTR_ERR(data->hwmon_dev);
 282                 goto exit_remove_files;
 283         }
 284
 285         return 0;
 286
 287       exit_remove_files:
 288         sysfs_remove_group(&client->dev.kobj, &ds1621_group);
 289       exit_free:
 290         kfree(data);
 291       exit:
 292         return err;
 293 }
 294
 295 static int ds1621_remove(struct i2c_client *client)
 296 {
 297         struct ds1621_data *data = i2c_get_clientdata(client);
 298
 299         hwmon_device_unregister(data->hwmon_dev);
 300         sysfs_remove_group(&client->dev.kobj, &ds1621_group);
 301
 302         kfree(data);
 303
 304         return 0;
 305 }
 306
 307 static const struct i2c_device_id ds1621_id[] = {
 308         { "ds1621", ds1621 },
 309         { "ds1625", ds1621 },
 310         { }
 311 };
 312 MODULE_DEVICE_TABLE(i2c, ds1621_id);
 313
 314 /* This is the driver that will be inserted */
 315 static struct i2c_driver ds1621_driver = {
 316         .class          = I2C_CLASS_HWMON,
 317         .driver = {
 318                 .name   = "ds1621",
 319         },
 320         .probe          = ds1621_probe,
 321         .remove         = ds1621_remove,
 322         .id_table       = ds1621_id,
 323         .detect         = ds1621_detect,
 324         .address_data   = &addr_data,
 325 };
 326
 327 static int __init ds1621_init(void)
 328 {
 329         return i2c_add_driver(&ds1621_driver);
 330 }
 331
 332 static void __exit ds1621_exit(void)
 333 {
 334         i2c_del_driver(&ds1621_driver);
 335 }
 336
 337
 338 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
 339 MODULE_DESCRIPTION("DS1621 driver");
 340 MODULE_LICENSE("GPL");
 341
 342 module_init(ds1621_init);
 343 module_exit(ds1621_exit);