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 #include <linux/jiffies.h>
  37
  38 #define THERMAL_PID_REG         0xfd
  39 #define THERMAL_SMSC_ID_REG     0xfe
  40 #define THERMAL_REVISION_REG    0xff
  41
  42 struct thermal_data {
  43         struct device *hwmon_dev;
  44         struct mutex mutex;
  45         /*
  46          * Cache the hyst value so we don't keep re-reading it. In theory
  47          * we could cache it forever as nobody else should be writing it.
  48          */
  49         u8 cached_hyst;
  50         unsigned long hyst_valid;
  51 };
  52
  53 static ssize_t show_temp(struct device *dev,
  54                         struct device_attribute *attr, char *buf)
  55 {
  56         struct i2c_client *client = to_i2c_client(dev);
  57         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  58         int retval = i2c_smbus_read_byte_data(client, sda->index);
  59
  60         if (retval < 0)
  61                 return retval;
  62         return sprintf(buf, "%d000\n", retval);
  63 }
  64
  65 static ssize_t show_bit(struct device *dev,
  66                         struct device_attribute *attr, char *buf)
  67 {
  68         struct i2c_client *client = to_i2c_client(dev);
  69         struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
  70         int retval = i2c_smbus_read_byte_data(client, sda->nr);
  71
  72         if (retval < 0)
  73                 return retval;
  74         retval &= sda->index;
  75         return sprintf(buf, "%d\n", retval ? 1 : 0);
  76 }
  77
  78 static ssize_t store_temp(struct device *dev,
  79                 struct device_attribute *attr, const char *buf, size_t count)
  80 {
  81         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  82         struct i2c_client *client = to_i2c_client(dev);
  83         unsigned long val;
  84         int retval;
  85
  86         if (kstrtoul(buf, 10, &val))
  87                 return -EINVAL;
  88         retval = i2c_smbus_write_byte_data(client, sda->index,
  89                                         DIV_ROUND_CLOSEST(val, 1000));
  90         if (retval < 0)
  91                 return retval;
  92         return count;
  93 }
  94
  95 static ssize_t store_bit(struct device *dev,
  96                 struct device_attribute *attr, const char *buf, size_t count)
  97 {
  98         struct i2c_client *client = to_i2c_client(dev);
  99         struct thermal_data *data = i2c_get_clientdata(client);
 100         struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
 101         unsigned long val;
 102         int retval;
 103
 104         if (kstrtoul(buf, 10, &val))
 105                 return -EINVAL;
 106
 107         mutex_lock(&data->mutex);
 108         retval = i2c_smbus_read_byte_data(client, sda->nr);
 109         if (retval < 0)
 110                 goto fail;
 111
 112         retval &= ~sda->index;
 113         if (val)
 114                 retval |= sda->index;
 115
 116         retval = i2c_smbus_write_byte_data(client, sda->index, retval);
 117         if (retval == 0)
 118                 retval = count;
 119 fail:
 120         mutex_unlock(&data->mutex);
 121         return retval;
 122 }
 123
 124 static ssize_t show_hyst(struct device *dev,
 125                         struct device_attribute *attr, char *buf)
 126 {
 127         struct i2c_client *client = to_i2c_client(dev);
 128         struct thermal_data *data = i2c_get_clientdata(client);
 129         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 130         int retval;
 131         int hyst;
 132
 133         retval = i2c_smbus_read_byte_data(client, sda->index);
 134         if (retval < 0)
 135                 return retval;
 136
 137         if (time_after(jiffies, data->hyst_valid)) {
 138                 hyst = i2c_smbus_read_byte_data(client, 0x21);
 139                 if (hyst < 0)
 140                         return retval;
 141                 data->cached_hyst = hyst;
 142                 data->hyst_valid = jiffies + HZ;
 143         }
 144         return sprintf(buf, "%d000\n", retval - data->cached_hyst);
 145 }
 146
 147 static ssize_t store_hyst(struct device *dev,
 148                 struct device_attribute *attr, const char *buf, size_t count)
 149 {
 150         struct i2c_client *client = to_i2c_client(dev);
 151         struct thermal_data *data = i2c_get_clientdata(client);
 152         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 153         int retval;
 154         int hyst;
 155         unsigned long val;
 156
 157         if (kstrtoul(buf, 10, &val))
 158                 return -EINVAL;
 159
 160         mutex_lock(&data->mutex);
 161         retval = i2c_smbus_read_byte_data(client, sda->index);
 162         if (retval < 0)
 163                 goto fail;
 164
 165         hyst = retval * 1000 - val;
 166         hyst = DIV_ROUND_CLOSEST(hyst, 1000);
 167         if (hyst < 0 || hyst > 255) {
 168                 retval = -ERANGE;
 169                 goto fail;
 170         }
 171
 172         retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
 173         if (retval == 0) {
 174                 retval = count;
 175                 data->cached_hyst = hyst;
 176                 data->hyst_valid = jiffies + HZ;
 177         }
 178 fail:
 179         mutex_unlock(&data->mutex);
 180         return retval;
 181 }
 182
 183 /*
 184  *      Sensors. We pass the actual i2c register to the methods.
 185  */
 186
 187 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
 188         show_temp, store_temp, 0x06);
 189 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
 190         show_temp, store_temp, 0x05);
 191 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
 192         show_temp, store_temp, 0x20);
 193 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
 194 static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
 195         show_bit, NULL, 0x36, 0x01);
 196 static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
 197         show_bit, NULL, 0x35, 0x01);
 198 static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
 199         show_bit, NULL, 0x37, 0x01);
 200 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
 201         show_hyst, store_hyst, 0x20);
 202
 203 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
 204         show_temp, store_temp, 0x08);
 205 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
 206         show_temp, store_temp, 0x07);
 207 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
 208         show_temp, store_temp, 0x19);
 209 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
 210 static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
 211         show_bit, NULL, 0x36, 0x02);
 212 static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
 213         show_bit, NULL, 0x35, 0x02);
 214 static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
 215         show_bit, NULL, 0x37, 0x02);
 216 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
 217         show_hyst, store_hyst, 0x19);
 218
 219 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
 220         show_temp, store_temp, 0x16);
 221 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
 222         show_temp, store_temp, 0x15);
 223 static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
 224         show_temp, store_temp, 0x1A);
 225 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
 226 static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
 227         show_bit, NULL, 0x36, 0x04);
 228 static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
 229         show_bit, NULL, 0x35, 0x04);
 230 static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
 231         show_bit, NULL, 0x37, 0x04);
 232 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
 233         show_hyst, store_hyst, 0x1A);
 234
 235 static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
 236         show_bit, store_bit, 0x03, 0x40);
 237
 238 static struct attribute *mid_att_thermal[] = {
 239         &sensor_dev_attr_temp1_min.dev_attr.attr,
 240         &sensor_dev_attr_temp1_max.dev_attr.attr,
 241         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 242         &sensor_dev_attr_temp1_input.dev_attr.attr,
 243         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 244         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 245         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 246         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 247         &sensor_dev_attr_temp2_min.dev_attr.attr,
 248         &sensor_dev_attr_temp2_max.dev_attr.attr,
 249         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 250         &sensor_dev_attr_temp2_input.dev_attr.attr,
 251         &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 252         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 253         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 254         &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
 255         &sensor_dev_attr_temp3_min.dev_attr.attr,
 256         &sensor_dev_attr_temp3_max.dev_attr.attr,
 257         &sensor_dev_attr_temp3_crit.dev_attr.attr,
 258         &sensor_dev_attr_temp3_input.dev_attr.attr,
 259         &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
 260         &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 261         &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 262         &sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
 263         &sensor_dev_attr_power_state.dev_attr.attr,
 264         NULL
 265 };
 266
 267 static const struct attribute_group m_thermal_gr = {
 268         .attrs = mid_att_thermal
 269 };
 270
 271 static int emc1403_detect(struct i2c_client *client,
 272                         struct i2c_board_info *info)
 273 {
 274         int id;
 275         /* Check if thermal chip is SMSC and EMC1403 or EMC1423 */
 276
 277         id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
 278         if (id != 0x5d)
 279                 return -ENODEV;
 280
 281         id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
 282         switch (id) {
 283         case 0x21:
 284                 strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
 285                 break;
 286         case 0x23:
 287                 strlcpy(info->type, "emc1423", I2C_NAME_SIZE);
 288                 break;
 289         /*
 290          * Note: 0x25 is the 1404 which is very similar and this
 291          * driver could be extended
 292          */
 293         default:
 294                 return -ENODEV;
 295         }
 296
 297         id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
 298         if (id < 0x01 || id > 0x04)
 299                 return -ENODEV;
 300
 301         return 0;
 302 }
 303
 304 static int emc1403_probe(struct i2c_client *client,
 305                         const struct i2c_device_id *id)
 306 {
 307         int res;
 308         struct thermal_data *data;
 309
 310         data = devm_kzalloc(&client->dev, sizeof(struct thermal_data),
 311                             GFP_KERNEL);
 312         if (data == NULL)
 313                 return -ENOMEM;
 314
 315         i2c_set_clientdata(client, data);
 316         mutex_init(&data->mutex);
 317         data->hyst_valid = jiffies - 1;         /* Expired */
 318
 319         res = sysfs_create_group(&client->dev.kobj, &m_thermal_gr);
 320         if (res) {
 321                 dev_warn(&client->dev, "create group failed\n");
 322                 return res;
 323         }
 324         data->hwmon_dev = hwmon_device_register(&client->dev);
 325         if (IS_ERR(data->hwmon_dev)) {
 326                 res = PTR_ERR(data->hwmon_dev);
 327                 dev_warn(&client->dev, "register hwmon dev failed\n");
 328                 goto thermal_error;
 329         }
 330         dev_info(&client->dev, "EMC1403 Thermal chip found\n");
 331         return 0;
 332
 333 thermal_error:
 334         sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
 335         return res;
 336 }
 337
 338 static int emc1403_remove(struct i2c_client *client)
 339 {
 340         struct thermal_data *data = i2c_get_clientdata(client);
 341
 342         hwmon_device_unregister(data->hwmon_dev);
 343         sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
 344         return 0;
 345 }
 346
 347 static const unsigned short emc1403_address_list[] = {
 348         0x18, 0x29, 0x4c, 0x4d, I2C_CLIENT_END
 349 };
 350
 351 static const struct i2c_device_id emc1403_idtable[] = {
 352         { "emc1403", 0 },
 353         { "emc1423", 0 },
 354         { }
 355 };
 356 MODULE_DEVICE_TABLE(i2c, emc1403_idtable);
 357
 358 static struct i2c_driver sensor_emc1403 = {
 359         .class = I2C_CLASS_HWMON,
 360         .driver = {
 361                 .name = "emc1403",
 362         },
 363         .detect = emc1403_detect,
 364         .probe = emc1403_probe,
 365         .remove = emc1403_remove,
 366         .id_table = emc1403_idtable,
 367         .address_list = emc1403_address_list,
 368 };
 369
 370 module_i2c_driver(sensor_emc1403);
 371
 372 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
 373 MODULE_DESCRIPTION("emc1403 Thermal Driver");
 374 MODULE_LICENSE("GPL v2");