drivers/hwmon/emc1403.c

   1 /*
   2  * emc1403.c - SMSC Thermal Driver
   3  *
   4  * Copyright (C) 2008 Intel Corp
   5  *
   6  *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  20  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  21  *
  22  * TODO
  23  *      -       cache alarm and critical limit registers
  24  *      -       add emc1404 support
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/slab.h>
  30 #include <linux/i2c.h>
  31 #include <linux/hwmon.h>
  32 #include <linux/hwmon-sysfs.h>
  33 #include <linux/err.h>
  34 #include <linux/sysfs.h>
  35 #include <linux/mutex.h>
  36
  37 #define THERMAL_PID_REG         0xfd
  38 #define THERMAL_SMSC_ID_REG     0xfe
  39 #define THERMAL_REVISION_REG    0xff
  40
  41 struct thermal_data {
  42         struct device *hwmon_dev;
  43         struct mutex mutex;
  44         /* Cache the hyst value so we don't keep re-reading it. In theory
  45            we could cache it forever as nobody else should be writing it. */
  46         u8 cached_hyst;
  47         unsigned long hyst_valid;
  48 };
  49
  50 static ssize_t show_temp(struct device *dev,
  51                         struct device_attribute *attr, char *buf)
  52 {
  53         struct i2c_client *client = to_i2c_client(dev);
  54         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  55         int retval = i2c_smbus_read_byte_data(client, sda->index);
  56
  57         if (retval < 0)
  58                 return retval;
  59         return sprintf(buf, "%d000\n", retval);
  60 }
  61
  62 static ssize_t show_bit(struct device *dev,
  63                         struct device_attribute *attr, char *buf)
  64 {
  65         struct i2c_client *client = to_i2c_client(dev);
  66         struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
  67         int retval = i2c_smbus_read_byte_data(client, sda->nr);
  68
  69         if (retval < 0)
  70                 return retval;
  71         retval &= sda->index;
  72         return sprintf(buf, "%d\n", retval ? 1 : 0);
  73 }
  74
  75 static ssize_t store_temp(struct device *dev,
  76                 struct device_attribute *attr, const char *buf, size_t count)
  77 {
  78         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  79         struct i2c_client *client = to_i2c_client(dev);
  80         unsigned long val;
  81         int retval;
  82
  83         if (strict_strtoul(buf, 10, &val))
  84                 return -EINVAL;
  85         retval = i2c_smbus_write_byte_data(client, sda->index,
  86                                         DIV_ROUND_CLOSEST(val, 1000));
  87         if (retval < 0)
  88                 return retval;
  89         return count;
  90 }
  91
  92 static ssize_t store_bit(struct device *dev,
  93                 struct device_attribute *attr, const char *buf, size_t count)
  94 {
  95         struct i2c_client *client = to_i2c_client(dev);
  96         struct thermal_data *data = i2c_get_clientdata(client);
  97         struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
  98         unsigned long val;
  99         int retval;
 100
 101         if (strict_strtoul(buf, 10, &val))
 102                 return -EINVAL;
 103
 104         mutex_lock(&data->mutex);
 105         retval = i2c_smbus_read_byte_data(client, sda->nr);
 106         if (retval < 0)
 107                 goto fail;
 108
 109         retval &= ~sda->index;
 110         if (val)
 111                 retval |= sda->index;
 112
 113         retval = i2c_smbus_write_byte_data(client, sda->index, retval);
 114         if (retval == 0)
 115                 retval = count;
 116 fail:
 117         mutex_unlock(&data->mutex);
 118         return retval;
 119 }
 120
 121 static ssize_t show_hyst(struct device *dev,
 122                         struct device_attribute *attr, char *buf)
 123 {
 124         struct i2c_client *client = to_i2c_client(dev);
 125         struct thermal_data *data = i2c_get_clientdata(client);
 126         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 127         int retval;
 128         int hyst;
 129
 130         retval = i2c_smbus_read_byte_data(client, sda->index);
 131         if (retval < 0)
 132                 return retval;
 133
 134         if (time_after(jiffies, data->hyst_valid)) {
 135                 hyst = i2c_smbus_read_byte_data(client, 0x21);
 136                 if (hyst < 0)
 137                         return retval;
 138                 data->cached_hyst = hyst;
 139                 data->hyst_valid = jiffies + HZ;
 140         }
 141         return sprintf(buf, "%d000\n", retval - data->cached_hyst);
 142 }
 143
 144 static ssize_t store_hyst(struct device *dev,
 145                 struct device_attribute *attr, const char *buf, size_t count)
 146 {
 147         struct i2c_client *client = to_i2c_client(dev);
 148         struct thermal_data *data = i2c_get_clientdata(client);
 149         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 150         int retval;
 151         int hyst;
 152         unsigned long val;
 153
 154         if (strict_strtoul(buf, 10, &val))
 155                 return -EINVAL;
 156
 157         mutex_lock(&data->mutex);
 158         retval = i2c_smbus_read_byte_data(client, sda->index);
 159         if (retval < 0)
 160                 goto fail;
 161
 162         hyst = val - retval * 1000;
 163         hyst = DIV_ROUND_CLOSEST(hyst, 1000);
 164         if (hyst < 0 || hyst > 255) {
 165                 retval = -ERANGE;
 166                 goto fail;
 167         }
 168
 169         retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
 170         if (retval == 0) {
 171                 retval = count;
 172                 data->cached_hyst = hyst;
 173                 data->hyst_valid = jiffies + HZ;
 174         }
 175 fail:
 176         mutex_unlock(&data->mutex);
 177         return retval;
 178 }
 179
 180 /*
 181  *      Sensors. We pass the actual i2c register to the methods.
 182  */
 183
 184 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
 185         show_temp, store_temp, 0x06);
 186 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
 187         show_temp, store_temp, 0x05);
 188 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
 189         show_temp, store_temp, 0x20);
 190 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
 191 static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
 192         show_bit, NULL, 0x36, 0x01);
 193 static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
 194         show_bit, NULL, 0x35, 0x01);
 195 static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
 196         show_bit, NULL, 0x37, 0x01);
 197 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
 198         show_hyst, store_hyst, 0x20);
 199
 200 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
 201         show_temp, store_temp, 0x08);
 202 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
 203         show_temp, store_temp, 0x07);
 204 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
 205         show_temp, store_temp, 0x19);
 206 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
 207 static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
 208         show_bit, NULL, 0x36, 0x02);
 209 static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
 210         show_bit, NULL, 0x35, 0x02);
 211 static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
 212         show_bit, NULL, 0x37, 0x02);
 213 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
 214         show_hyst, store_hyst, 0x19);
 215
 216 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
 217         show_temp, store_temp, 0x16);
 218 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
 219         show_temp, store_temp, 0x15);
 220 static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
 221         show_temp, store_temp, 0x1A);
 222 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
 223 static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
 224         show_bit, NULL, 0x36, 0x04);
 225 static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
 226         show_bit, NULL, 0x35, 0x04);
 227 static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
 228         show_bit, NULL, 0x37, 0x04);
 229 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
 230         show_hyst, store_hyst, 0x1A);
 231
 232 static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
 233         show_bit, store_bit, 0x03, 0x40);
 234
 235 static struct attribute *mid_att_thermal[] = {
 236         &sensor_dev_attr_temp1_min.dev_attr.attr,
 237         &sensor_dev_attr_temp1_max.dev_attr.attr,
 238         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 239         &sensor_dev_attr_temp1_input.dev_attr.attr,
 240         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 241         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 242         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 243         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 244         &sensor_dev_attr_temp2_min.dev_attr.attr,
 245         &sensor_dev_attr_temp2_max.dev_attr.attr,
 246         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 247         &sensor_dev_attr_temp2_input.dev_attr.attr,
 248         &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 249         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 250         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 251         &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
 252         &sensor_dev_attr_temp3_min.dev_attr.attr,
 253         &sensor_dev_attr_temp3_max.dev_attr.attr,
 254         &sensor_dev_attr_temp3_crit.dev_attr.attr,
 255         &sensor_dev_attr_temp3_input.dev_attr.attr,
 256         &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
 257         &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 258         &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 259         &sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
 260         &sensor_dev_attr_power_state.dev_attr.attr,
 261         NULL
 262 };
 263
 264 static const struct attribute_group m_thermal_gr = {
 265         .attrs = mid_att_thermal
 266 };
 267
 268 static int emc1403_detect(struct i2c_client *client,
 269                         struct i2c_board_info *info)
 270 {
 271         int id;
 272         /* Check if thermal chip is SMSC and EMC1403 */
 273
 274         id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
 275         if (id != 0x5d)
 276                 return -ENODEV;
 277
 278         /* Note: 0x25 is the 1404 which is very similar and this
 279            driver could be extended */
 280         id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
 281         if (id != 0x21)
 282                 return -ENODEV;
 283
 284         id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
 285         if (id != 0x01)
 286                 return -ENODEV;
 287
 288         strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
 289         return 0;
 290 }
 291
 292 static int emc1403_probe(struct i2c_client *client,
 293                         const struct i2c_device_id *id)
 294 {
 295         int res;
 296         struct thermal_data *data;
 297
 298         data = kzalloc(sizeof(struct thermal_data), GFP_KERNEL);
 299         if (data == NULL) {
 300                 dev_warn(&client->dev, "out of memory");
 301                 return -ENOMEM;
 302         }
 303
 304         i2c_set_clientdata(client, data);
 305         mutex_init(&data->mutex);
 306         data->hyst_valid = jiffies - 1;         /* Expired */
 307
 308         res = sysfs_create_group(&client->dev.kobj, &m_thermal_gr);
 309         if (res) {
 310                 dev_warn(&client->dev, "create group failed\n");
 311                 goto thermal_error1;
 312         }
 313         data->hwmon_dev = hwmon_device_register(&client->dev);
 314         if (IS_ERR(data->hwmon_dev)) {
 315                 res = PTR_ERR(data->hwmon_dev);
 316                 dev_warn(&client->dev, "register hwmon dev failed\n");
 317                 goto thermal_error2;
 318         }
 319         dev_info(&client->dev, "EMC1403 Thermal chip found\n");
 320         return res;
 321
 322 thermal_error2:
 323         sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
 324 thermal_error1:
 325         kfree(data);
 326         return res;
 327 }
 328
 329 static int emc1403_remove(struct i2c_client *client)
 330 {
 331         struct thermal_data *data = i2c_get_clientdata(client);
 332
 333         hwmon_device_unregister(data->hwmon_dev);
 334         sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
 335         kfree(data);
 336         return 0;
 337 }
 338
 339 static const unsigned short emc1403_address_list[] = {
 340         0x18, 0x2a, 0x4c, 0x4d, I2C_CLIENT_END
 341 };
 342
 343 static const struct i2c_device_id emc1403_idtable[] = {
 344         { "emc1403", 0 },
 345         { }
 346 };
 347 MODULE_DEVICE_TABLE(i2c, emc1403_idtable);
 348
 349 static struct i2c_driver sensor_emc1403 = {
 350         .class = I2C_CLASS_HWMON,
 351         .driver = {
 352                 .name = "emc1403",
 353         },
 354         .detect = emc1403_detect,
 355         .probe = emc1403_probe,
 356         .remove = emc1403_remove,
 357         .id_table = emc1403_idtable,
 358         .address_list = emc1403_address_list,
 359 };
 360
 361 static int __init sensor_emc1403_init(void)
 362 {
 363         return i2c_add_driver(&sensor_emc1403);
 364 }
 365
 366 static void  __exit sensor_emc1403_exit(void)
 367 {
 368         i2c_del_driver(&sensor_emc1403);
 369 }
 370
 371 module_init(sensor_emc1403_init);
 372 module_exit(sensor_emc1403_exit);
 373
 374 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
 375 MODULE_DESCRIPTION("emc1403 Thermal Driver");
 376 MODULE_LICENSE("GPL v2");