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 show_hyst(struct device *dev,
  93                         struct device_attribute *attr, char *buf)
  94 {
  95         struct i2c_client *client = to_i2c_client(dev);
  96         struct thermal_data *data = i2c_get_clientdata(client);
  97         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  98         int retval;
  99         int hyst;
 100
 101         retval = i2c_smbus_read_byte_data(client, sda->index);
 102         if (retval < 0)
 103                 return retval;
 104
 105         if (time_after(jiffies, data->hyst_valid)) {
 106                 hyst = i2c_smbus_read_byte_data(client, 0x21);
 107                 if (hyst < 0)
 108                         return retval;
 109                 data->cached_hyst = hyst;
 110                 data->hyst_valid = jiffies + HZ;
 111         }
 112         return sprintf(buf, "%d000\n", retval - data->cached_hyst);
 113 }
 114
 115 static ssize_t store_hyst(struct device *dev,
 116                 struct device_attribute *attr, const char *buf, size_t count)
 117 {
 118         struct i2c_client *client = to_i2c_client(dev);
 119         struct thermal_data *data = i2c_get_clientdata(client);
 120         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 121         int retval;
 122         int hyst;
 123         unsigned long val;
 124
 125         if (strict_strtoul(buf, 10, &val))
 126                 return -EINVAL;
 127
 128         mutex_lock(&data->mutex);
 129         retval = i2c_smbus_read_byte_data(client, sda->index);
 130         if (retval < 0)
 131                 goto fail;
 132
 133         hyst = val - retval * 1000;
 134         hyst = DIV_ROUND_CLOSEST(hyst, 1000);
 135         if (hyst < 0 || hyst > 255) {
 136                 retval = -ERANGE;
 137                 goto fail;
 138         }
 139
 140         retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
 141         if (retval == 0) {
 142                 retval = count;
 143                 data->cached_hyst = hyst;
 144                 data->hyst_valid = jiffies + HZ;
 145         }
 146 fail:
 147         mutex_unlock(&data->mutex);
 148         return retval;
 149 }
 150
 151 /*
 152  *      Sensors. We pass the actual i2c register to the methods.
 153  */
 154
 155 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
 156         show_temp, store_temp, 0x06);
 157 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
 158         show_temp, store_temp, 0x05);
 159 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
 160         show_temp, store_temp, 0x20);
 161 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
 162 static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
 163         show_bit, NULL, 0x36, 0x01);
 164 static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
 165         show_bit, NULL, 0x35, 0x01);
 166 static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
 167         show_bit, NULL, 0x37, 0x01);
 168 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
 169         show_hyst, store_hyst, 0x20);
 170
 171 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
 172         show_temp, store_temp, 0x08);
 173 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
 174         show_temp, store_temp, 0x07);
 175 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
 176         show_temp, store_temp, 0x19);
 177 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
 178 static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
 179         show_bit, NULL, 0x36, 0x02);
 180 static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
 181         show_bit, NULL, 0x35, 0x02);
 182 static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
 183         show_bit, NULL, 0x37, 0x02);
 184 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
 185         show_hyst, store_hyst, 0x19);
 186
 187 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
 188         show_temp, store_temp, 0x16);
 189 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
 190         show_temp, store_temp, 0x15);
 191 static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
 192         show_temp, store_temp, 0x1A);
 193 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
 194 static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
 195         show_bit, NULL, 0x36, 0x04);
 196 static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
 197         show_bit, NULL, 0x35, 0x04);
 198 static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
 199         show_bit, NULL, 0x37, 0x04);
 200 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
 201         show_hyst, store_hyst, 0x1A);
 202
 203 static struct attribute *mid_att_thermal[] = {
 204         &sensor_dev_attr_temp1_min.dev_attr.attr,
 205         &sensor_dev_attr_temp1_max.dev_attr.attr,
 206         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 207         &sensor_dev_attr_temp1_input.dev_attr.attr,
 208         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 209         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 210         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 211         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 212         &sensor_dev_attr_temp2_min.dev_attr.attr,
 213         &sensor_dev_attr_temp2_max.dev_attr.attr,
 214         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 215         &sensor_dev_attr_temp2_input.dev_attr.attr,
 216         &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 217         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 218         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 219         &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
 220         &sensor_dev_attr_temp3_min.dev_attr.attr,
 221         &sensor_dev_attr_temp3_max.dev_attr.attr,
 222         &sensor_dev_attr_temp3_crit.dev_attr.attr,
 223         &sensor_dev_attr_temp3_input.dev_attr.attr,
 224         &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
 225         &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 226         &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 227         &sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
 228         NULL
 229 };
 230
 231 static const struct attribute_group m_thermal_gr = {
 232         .attrs = mid_att_thermal
 233 };
 234
 235 static int emc1403_detect(struct i2c_client *client,
 236                         struct i2c_board_info *info)
 237 {
 238         int id;
 239         /* Check if thermal chip is SMSC and EMC1403 */
 240
 241         id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
 242         if (id != 0x5d)
 243                 return -ENODEV;
 244
 245         /* Note: 0x25 is the 1404 which is very similar and this
 246            driver could be extended */
 247         id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
 248         if (id != 0x21)
 249                 return -ENODEV;
 250
 251         id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
 252         if (id != 0x01)
 253                 return -ENODEV;
 254
 255         strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
 256         return 0;
 257 }
 258
 259 static int emc1403_probe(struct i2c_client *client,
 260                         const struct i2c_device_id *id)
 261 {
 262         int res;
 263         struct thermal_data *data;
 264
 265         data = kzalloc(sizeof(struct thermal_data), GFP_KERNEL);
 266         if (data == NULL) {
 267                 dev_warn(&client->dev, "out of memory");
 268                 return -ENOMEM;
 269         }
 270
 271         i2c_set_clientdata(client, data);
 272         mutex_init(&data->mutex);
 273         data->hyst_valid = jiffies - 1;         /* Expired */
 274
 275         res = sysfs_create_group(&client->dev.kobj, &m_thermal_gr);
 276         if (res) {
 277                 dev_warn(&client->dev, "create group failed\n");
 278                 hwmon_device_unregister(data->hwmon_dev);
 279                 goto thermal_error1;
 280         }
 281         data->hwmon_dev = hwmon_device_register(&client->dev);
 282         if (IS_ERR(data->hwmon_dev)) {
 283                 res = PTR_ERR(data->hwmon_dev);
 284                 dev_warn(&client->dev, "register hwmon dev failed\n");
 285                 goto thermal_error2;
 286         }
 287         dev_info(&client->dev, "EMC1403 Thermal chip found\n");
 288         return res;
 289
 290 thermal_error2:
 291         sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
 292 thermal_error1:
 293         kfree(data);
 294         return res;
 295 }
 296
 297 static int emc1403_remove(struct i2c_client *client)
 298 {
 299         struct thermal_data *data = i2c_get_clientdata(client);
 300
 301         hwmon_device_unregister(data->hwmon_dev);
 302         sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
 303         kfree(data);
 304         return 0;
 305 }
 306
 307 static const unsigned short emc1403_address_list[] = {
 308         0x18, 0x2a, 0x4c, 0x4d, I2C_CLIENT_END
 309 };
 310
 311 static const struct i2c_device_id emc1403_idtable[] = {
 312         { "emc1403", 0 },
 313         { }
 314 };
 315 MODULE_DEVICE_TABLE(i2c, emc1403_idtable);
 316
 317 static struct i2c_driver sensor_emc1403 = {
 318         .class = I2C_CLASS_HWMON,
 319         .driver = {
 320                 .name = "emc1403",
 321         },
 322         .detect = emc1403_detect,
 323         .probe = emc1403_probe,
 324         .remove = emc1403_remove,
 325         .id_table = emc1403_idtable,
 326         .address_list = emc1403_address_list,
 327 };
 328
 329 static int __init sensor_emc1403_init(void)
 330 {
 331         return i2c_add_driver(&sensor_emc1403);
 332 }
 333
 334 static void  __exit sensor_emc1403_exit(void)
 335 {
 336         i2c_del_driver(&sensor_emc1403);
 337 }
 338
 339 module_init(sensor_emc1403_init);
 340 module_exit(sensor_emc1403_exit);
 341
 342 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
 343 MODULE_DESCRIPTION("emc1403 Thermal Driver");
 344 MODULE_LICENSE("GPL v2");