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 i2c_client *client;
  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 sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  57         struct thermal_data *data = dev_get_drvdata(dev);
  58         int retval;
  59
  60         retval = i2c_smbus_read_byte_data(data->client, sda->index);
  61         if (retval < 0)
  62                 return retval;
  63         return sprintf(buf, "%d000\n", retval);
  64 }
  65
  66 static ssize_t show_bit(struct device *dev,
  67                         struct device_attribute *attr, char *buf)
  68 {
  69         struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
  70         struct thermal_data *data = dev_get_drvdata(dev);
  71         int retval;
  72
  73         retval = i2c_smbus_read_byte_data(data->client, sda->nr);
  74         if (retval < 0)
  75                 return retval;
  76         return sprintf(buf, "%d\n", !!(retval & sda->index));
  77 }
  78
  79 static ssize_t store_temp(struct device *dev,
  80                 struct device_attribute *attr, const char *buf, size_t count)
  81 {
  82         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  83         struct thermal_data *data = dev_get_drvdata(dev);
  84         unsigned long val;
  85         int retval;
  86
  87         if (kstrtoul(buf, 10, &val))
  88                 return -EINVAL;
  89         retval = i2c_smbus_write_byte_data(data->client, sda->index,
  90                                         DIV_ROUND_CLOSEST(val, 1000));
  91         if (retval < 0)
  92                 return retval;
  93         return count;
  94 }
  95
  96 static ssize_t store_bit(struct device *dev,
  97                 struct device_attribute *attr, const char *buf, size_t count)
  98 {
  99         struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
 100         struct thermal_data *data = dev_get_drvdata(dev);
 101         struct i2c_client *client = data->client;
 102         unsigned long val;
 103         int retval;
 104
 105         if (kstrtoul(buf, 10, &val))
 106                 return -EINVAL;
 107
 108         mutex_lock(&data->mutex);
 109         retval = i2c_smbus_read_byte_data(client, sda->nr);
 110         if (retval < 0)
 111                 goto fail;
 112
 113         retval &= ~sda->index;
 114         if (val)
 115                 retval |= sda->index;
 116
 117         retval = i2c_smbus_write_byte_data(client, sda->index, retval);
 118         if (retval == 0)
 119                 retval = count;
 120 fail:
 121         mutex_unlock(&data->mutex);
 122         return retval;
 123 }
 124
 125 static ssize_t show_hyst(struct device *dev,
 126                         struct device_attribute *attr, char *buf)
 127 {
 128         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 129         struct thermal_data *data = dev_get_drvdata(dev);
 130         struct i2c_client *client = data->client;
 131         int retval;
 132         int hyst;
 133
 134         retval = i2c_smbus_read_byte_data(client, sda->index);
 135         if (retval < 0)
 136                 return retval;
 137
 138         if (time_after(jiffies, data->hyst_valid)) {
 139                 hyst = i2c_smbus_read_byte_data(client, 0x21);
 140                 if (hyst < 0)
 141                         return retval;
 142                 data->cached_hyst = hyst;
 143                 data->hyst_valid = jiffies + HZ;
 144         }
 145         return sprintf(buf, "%d000\n", retval - data->cached_hyst);
 146 }
 147
 148 static ssize_t store_hyst(struct device *dev,
 149                 struct device_attribute *attr, const char *buf, size_t count)
 150 {
 151         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 152         struct thermal_data *data = dev_get_drvdata(dev);
 153         struct i2c_client *client = data->client;
 154         int retval;
 155         int hyst;
 156         unsigned long val;
 157
 158         if (kstrtoul(buf, 10, &val))
 159                 return -EINVAL;
 160
 161         mutex_lock(&data->mutex);
 162         retval = i2c_smbus_read_byte_data(client, sda->index);
 163         if (retval < 0)
 164                 goto fail;
 165
 166         hyst = val - retval * 1000;
 167         hyst = DIV_ROUND_CLOSEST(hyst, 1000);
 168         if (hyst < 0 || hyst > 255) {
 169                 retval = -ERANGE;
 170                 goto fail;
 171         }
 172
 173         retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
 174         if (retval == 0) {
 175                 retval = count;
 176                 data->cached_hyst = hyst;
 177                 data->hyst_valid = jiffies + HZ;
 178         }
 179 fail:
 180         mutex_unlock(&data->mutex);
 181         return retval;
 182 }
 183
 184 /*
 185  *      Sensors. We pass the actual i2c register to the methods.
 186  */
 187
 188 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
 189         show_temp, store_temp, 0x06);
 190 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
 191         show_temp, store_temp, 0x05);
 192 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
 193         show_temp, store_temp, 0x20);
 194 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
 195 static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
 196         show_bit, NULL, 0x36, 0x01);
 197 static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
 198         show_bit, NULL, 0x35, 0x01);
 199 static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
 200         show_bit, NULL, 0x37, 0x01);
 201 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
 202         show_hyst, store_hyst, 0x20);
 203
 204 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
 205         show_temp, store_temp, 0x08);
 206 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
 207         show_temp, store_temp, 0x07);
 208 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
 209         show_temp, store_temp, 0x19);
 210 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
 211 static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
 212         show_bit, NULL, 0x36, 0x02);
 213 static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
 214         show_bit, NULL, 0x35, 0x02);
 215 static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
 216         show_bit, NULL, 0x37, 0x02);
 217 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
 218         show_hyst, store_hyst, 0x19);
 219
 220 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
 221         show_temp, store_temp, 0x16);
 222 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
 223         show_temp, store_temp, 0x15);
 224 static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
 225         show_temp, store_temp, 0x1A);
 226 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
 227 static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
 228         show_bit, NULL, 0x36, 0x04);
 229 static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
 230         show_bit, NULL, 0x35, 0x04);
 231 static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
 232         show_bit, NULL, 0x37, 0x04);
 233 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
 234         show_hyst, store_hyst, 0x1A);
 235
 236 static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
 237         show_bit, store_bit, 0x03, 0x40);
 238
 239 static struct attribute *emc1403_attrs[] = {
 240         &sensor_dev_attr_temp1_min.dev_attr.attr,
 241         &sensor_dev_attr_temp1_max.dev_attr.attr,
 242         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 243         &sensor_dev_attr_temp1_input.dev_attr.attr,
 244         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 245         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 246         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 247         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 248         &sensor_dev_attr_temp2_min.dev_attr.attr,
 249         &sensor_dev_attr_temp2_max.dev_attr.attr,
 250         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 251         &sensor_dev_attr_temp2_input.dev_attr.attr,
 252         &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 253         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 254         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 255         &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
 256         &sensor_dev_attr_temp3_min.dev_attr.attr,
 257         &sensor_dev_attr_temp3_max.dev_attr.attr,
 258         &sensor_dev_attr_temp3_crit.dev_attr.attr,
 259         &sensor_dev_attr_temp3_input.dev_attr.attr,
 260         &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
 261         &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 262         &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 263         &sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
 264         &sensor_dev_attr_power_state.dev_attr.attr,
 265         NULL
 266 };
 267 ATTRIBUTE_GROUPS(emc1403);
 268
 269 static int emc1403_detect(struct i2c_client *client,
 270                         struct i2c_board_info *info)
 271 {
 272         int id;
 273         /* Check if thermal chip is SMSC and EMC1403 or EMC1423 */
 274
 275         id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
 276         if (id != 0x5d)
 277                 return -ENODEV;
 278
 279         id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
 280         switch (id) {
 281         case 0x21:
 282                 strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
 283                 break;
 284         case 0x23:
 285                 strlcpy(info->type, "emc1423", I2C_NAME_SIZE);
 286                 break;
 287         /*
 288          * Note: 0x25 is the 1404 which is very similar and this
 289          * driver could be extended
 290          */
 291         default:
 292                 return -ENODEV;
 293         }
 294
 295         id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
 296         if (id != 0x01)
 297                 return -ENODEV;
 298
 299         return 0;
 300 }
 301
 302 static int emc1403_probe(struct i2c_client *client,
 303                         const struct i2c_device_id *id)
 304 {
 305         struct thermal_data *data;
 306         struct device *hwmon_dev;
 307
 308         data = devm_kzalloc(&client->dev, sizeof(struct thermal_data),
 309                             GFP_KERNEL);
 310         if (data == NULL)
 311                 return -ENOMEM;
 312
 313         data->client = client;
 314         mutex_init(&data->mutex);
 315         data->hyst_valid = jiffies - 1;         /* Expired */
 316
 317         hwmon_dev = hwmon_device_register_with_groups(&client->dev,
 318                                                       client->name, data,
 319                                                       emc1403_groups);
 320         if (IS_ERR(hwmon_dev))
 321                 return PTR_ERR(hwmon_dev);
 322
 323         dev_info(&client->dev, "EMC1403 Thermal chip found\n");
 324         return 0;
 325 }
 326
 327 static const unsigned short emc1403_address_list[] = {
 328         0x18, 0x29, 0x4c, 0x4d, I2C_CLIENT_END
 329 };
 330
 331 static const struct i2c_device_id emc1403_idtable[] = {
 332         { "emc1403", 0 },
 333         { "emc1423", 0 },
 334         { }
 335 };
 336 MODULE_DEVICE_TABLE(i2c, emc1403_idtable);
 337
 338 static struct i2c_driver sensor_emc1403 = {
 339         .class = I2C_CLASS_HWMON,
 340         .driver = {
 341                 .name = "emc1403",
 342         },
 343         .detect = emc1403_detect,
 344         .probe = emc1403_probe,
 345         .id_table = emc1403_idtable,
 346         .address_list = emc1403_address_list,
 347 };
 348
 349 module_i2c_driver(sensor_emc1403);
 350
 351 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
 352 MODULE_DESCRIPTION("emc1403 Thermal Driver");
 353 MODULE_LICENSE("GPL v2");