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 <<<<<<< HEAD:drivers/hwmon/ds1621.c
  38 static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
  39 =======
  40 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
  41 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/hwmon/ds1621.c
  42                                         0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
  43
  44 /* Insmod parameters */
  45 I2C_CLIENT_INSMOD_1(ds1621);
  46 static int polarity = -1;
  47 module_param(polarity, int, 0);
  48 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
  49
  50 /* Many DS1621 constants specified below */
  51 /* Config register used for detection         */
  52 /*  7    6    5    4    3    2    1    0      */
  53 /* |Done|THF |TLF |NVB | X  | X  |POL |1SHOT| */
  54 #define DS1621_REG_CONFIG_NVB           0x10
  55 #define DS1621_REG_CONFIG_POLARITY      0x02
  56 #define DS1621_REG_CONFIG_1SHOT         0x01
  57 #define DS1621_REG_CONFIG_DONE          0x80
  58
  59 /* The DS1621 registers */
  60 static const u8 DS1621_REG_TEMP[3] = {
  61         0xAA,           /* input, word, RO */
  62         0xA2,           /* min, word, RW */
  63         0xA1,           /* max, word, RW */
  64 };
  65 #define DS1621_REG_CONF                 0xAC /* byte, RW */
  66 #define DS1621_COM_START                0xEE /* no data */
  67 #define DS1621_COM_STOP                 0x22 /* no data */
  68
  69 /* The DS1621 configuration register */
  70 #define DS1621_ALARM_TEMP_HIGH          0x40
  71 #define DS1621_ALARM_TEMP_LOW           0x20
  72
  73 /* Conversions */
  74 #define ALARMS_FROM_REG(val) ((val) & \
  75                               (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
  76
  77 /* Each client has this additional data */
  78 struct ds1621_data {
  79         struct i2c_client client;
  80         struct device *hwmon_dev;
  81         struct mutex update_lock;
  82         char valid;                     /* !=0 if following fields are valid */
  83         unsigned long last_updated;     /* In jiffies */
  84
  85         u16 temp[3];                    /* Register values, word */
  86         u8 conf;                        /* Register encoding, combined */
  87 };
  88
  89 static int ds1621_attach_adapter(struct i2c_adapter *adapter);
  90 static int ds1621_detect(struct i2c_adapter *adapter, int address,
  91                          int kind);
  92 static void ds1621_init_client(struct i2c_client *client);
  93 static int ds1621_detach_client(struct i2c_client *client);
  94 static struct ds1621_data *ds1621_update_client(struct device *dev);
  95
  96 /* This is the driver that will be inserted */
  97 static struct i2c_driver ds1621_driver = {
  98         .driver = {
  99                 .name   = "ds1621",
 100         },
 101         .attach_adapter = ds1621_attach_adapter,
 102         .detach_client  = ds1621_detach_client,
 103 };
 104
 105 /* All registers are word-sized, except for the configuration register.
 106    DS1621 uses a high-byte first convention, which is exactly opposite to
 107    the SMBus standard. */
 108 static int ds1621_read_value(struct i2c_client *client, u8 reg)
 109 {
 110         if (reg == DS1621_REG_CONF)
 111                 return i2c_smbus_read_byte_data(client, reg);
 112         else
 113                 return swab16(i2c_smbus_read_word_data(client, reg));
 114 }
 115
 116 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
 117 {
 118         if (reg == DS1621_REG_CONF)
 119                 return i2c_smbus_write_byte_data(client, reg, value);
 120         else
 121                 return i2c_smbus_write_word_data(client, reg, swab16(value));
 122 }
 123
 124 static void ds1621_init_client(struct i2c_client *client)
 125 {
 126         int reg = ds1621_read_value(client, DS1621_REG_CONF);
 127         /* switch to continuous conversion mode */
 128         reg &= ~ DS1621_REG_CONFIG_1SHOT;
 129
 130         /* setup output polarity */
 131         if (polarity == 0)
 132                 reg &= ~DS1621_REG_CONFIG_POLARITY;
 133         else if (polarity == 1)
 134                 reg |= DS1621_REG_CONFIG_POLARITY;
 135
 136         ds1621_write_value(client, DS1621_REG_CONF, reg);
 137
 138         /* start conversion */
 139         i2c_smbus_write_byte(client, DS1621_COM_START);
 140 }
 141
 142 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
 143                          char *buf)
 144 {
 145         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 146         struct ds1621_data *data = ds1621_update_client(dev);
 147         return sprintf(buf, "%d\n",
 148                        LM75_TEMP_FROM_REG(data->temp[attr->index]));
 149 }
 150
 151 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
 152                         const char *buf, size_t count)
 153 {
 154         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 155         struct i2c_client *client = to_i2c_client(dev);
 156         struct ds1621_data *data = ds1621_update_client(dev);
 157         u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10));
 158
 159         mutex_lock(&data->update_lock);
 160         data->temp[attr->index] = val;
 161         ds1621_write_value(client, DS1621_REG_TEMP[attr->index],
 162                            data->temp[attr->index]);
 163         mutex_unlock(&data->update_lock);
 164         return count;
 165 }
 166
 167 static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
 168                            char *buf)
 169 {
 170         struct ds1621_data *data = ds1621_update_client(dev);
 171         return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
 172 }
 173
 174 static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
 175                           char *buf)
 176 {
 177         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 178         struct ds1621_data *data = ds1621_update_client(dev);
 179         return sprintf(buf, "%d\n", !!(data->conf & attr->index));
 180 }
 181
 182 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 183 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 184 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
 185 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
 186 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 187                 DS1621_ALARM_TEMP_LOW);
 188 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 189                 DS1621_ALARM_TEMP_HIGH);
 190
 191 static struct attribute *ds1621_attributes[] = {
 192         &sensor_dev_attr_temp1_input.dev_attr.attr,
 193         &sensor_dev_attr_temp1_min.dev_attr.attr,
 194         &sensor_dev_attr_temp1_max.dev_attr.attr,
 195         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 196         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 197         &dev_attr_alarms.attr,
 198         NULL
 199 };
 200
 201 static const struct attribute_group ds1621_group = {
 202         .attrs = ds1621_attributes,
 203 };
 204
 205
 206 static int ds1621_attach_adapter(struct i2c_adapter *adapter)
 207 {
 208         if (!(adapter->class & I2C_CLASS_HWMON))
 209                 return 0;
 210         return i2c_probe(adapter, &addr_data, ds1621_detect);
 211 }
 212
 213 /* This function is called by i2c_probe */
 214 static int ds1621_detect(struct i2c_adapter *adapter, int address,
 215                          int kind)
 216 {
 217         int conf, temp;
 218         struct i2c_client *client;
 219         struct ds1621_data *data;
 220         int i, err = 0;
 221
 222         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
 223                                      | I2C_FUNC_SMBUS_WORD_DATA
 224                                      | I2C_FUNC_SMBUS_WRITE_BYTE))
 225                 goto exit;
 226
 227         /* OK. For now, we presume we have a valid client. We now create the
 228            client structure, even though we cannot fill it completely yet.
 229            But it allows us to access ds1621_{read,write}_value. */
 230         if (!(data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
 231                 err = -ENOMEM;
 232                 goto exit;
 233         }
 234
 235         client = &data->client;
 236         i2c_set_clientdata(client, data);
 237         client->addr = address;
 238         client->adapter = adapter;
 239         client->driver = &ds1621_driver;
 240
 241         /* Now, we do the remaining detection. It is lousy. */
 242         if (kind < 0) {
 243                 /* The NVB bit should be low if no EEPROM write has been
 244                    requested during the latest 10ms, which is highly
 245                    improbable in our case. */
 246                 conf = ds1621_read_value(client, DS1621_REG_CONF);
 247                 if (conf & DS1621_REG_CONFIG_NVB)
 248                         goto exit_free;
 249                 /* The 7 lowest bits of a temperature should always be 0. */
 250                 for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
 251                         temp = ds1621_read_value(client, DS1621_REG_TEMP[i]);
 252                         if (temp & 0x007f)
 253                                 goto exit_free;
 254                 }
 255         }
 256
 257         /* Fill in remaining client fields and put it into the global list */
 258         strlcpy(client->name, "ds1621", I2C_NAME_SIZE);
 259         mutex_init(&data->update_lock);
 260
 261         /* Tell the I2C layer a new client has arrived */
 262         if ((err = i2c_attach_client(client)))
 263                 goto exit_free;
 264
 265         /* Initialize the DS1621 chip */
 266         ds1621_init_client(client);
 267
 268         /* Register sysfs hooks */
 269         if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group)))
 270                 goto exit_detach;
 271
 272         data->hwmon_dev = hwmon_device_register(&client->dev);
 273         if (IS_ERR(data->hwmon_dev)) {
 274                 err = PTR_ERR(data->hwmon_dev);
 275                 goto exit_remove_files;
 276         }
 277
 278         return 0;
 279
 280       exit_remove_files:
 281         sysfs_remove_group(&client->dev.kobj, &ds1621_group);
 282       exit_detach:
 283         i2c_detach_client(client);
 284       exit_free:
 285         kfree(data);
 286       exit:
 287         return err;
 288 }
 289
 290 static int ds1621_detach_client(struct i2c_client *client)
 291 {
 292         struct ds1621_data *data = i2c_get_clientdata(client);
 293         int err;
 294
 295         hwmon_device_unregister(data->hwmon_dev);
 296         sysfs_remove_group(&client->dev.kobj, &ds1621_group);
 297
 298         if ((err = i2c_detach_client(client)))
 299                 return err;
 300
 301         kfree(data);
 302
 303         return 0;
 304 }
 305
 306
 307 static struct ds1621_data *ds1621_update_client(struct device *dev)
 308 {
 309         struct i2c_client *client = to_i2c_client(dev);
 310         struct ds1621_data *data = i2c_get_clientdata(client);
 311         u8 new_conf;
 312
 313         mutex_lock(&data->update_lock);
 314
 315         if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 316             || !data->valid) {
 317                 int i;
 318
 319                 dev_dbg(&client->dev, "Starting ds1621 update\n");
 320
 321                 data->conf = ds1621_read_value(client, DS1621_REG_CONF);
 322
 323                 for (i = 0; i < ARRAY_SIZE(data->temp); i++)
 324                         data->temp[i] = ds1621_read_value(client,
 325                                                           DS1621_REG_TEMP[i]);
 326
 327                 /* reset alarms if necessary */
 328                 new_conf = data->conf;
 329                 if (data->temp[0] > data->temp[1])      /* input > min */
 330                         new_conf &= ~DS1621_ALARM_TEMP_LOW;
 331                 if (data->temp[0] < data->temp[2])      /* input < max */
 332                         new_conf &= ~DS1621_ALARM_TEMP_HIGH;
 333                 if (data->conf != new_conf)
 334                         ds1621_write_value(client, DS1621_REG_CONF,
 335                                            new_conf);
 336
 337                 data->last_updated = jiffies;
 338                 data->valid = 1;
 339         }
 340
 341         mutex_unlock(&data->update_lock);
 342
 343         return data;
 344 }
 345
 346 static int __init ds1621_init(void)
 347 {
 348         return i2c_add_driver(&ds1621_driver);
 349 }
 350
 351 static void __exit ds1621_exit(void)
 352 {
 353         i2c_del_driver(&ds1621_driver);
 354 }
 355
 356
 357 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
 358 MODULE_DESCRIPTION("DS1621 driver");
 359 MODULE_LICENSE("GPL");
 360
 361 module_init(ds1621_init);
 362 module_exit(ds1621_exit);