linux/drivers/hwmon/emc1403.c
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   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
  41struct thermal_data {
  42        struct device *hwmon_dev;
  43        struct mutex mutex;
  44        /*
  45         * Cache the hyst value so we don't keep re-reading it. In theory
  46         * we could cache it forever as nobody else should be writing it.
  47         */
  48        u8 cached_hyst;
  49        unsigned long hyst_valid;
  50};
  51
  52static ssize_t show_temp(struct device *dev,
  53                        struct device_attribute *attr, char *buf)
  54{
  55        struct i2c_client *client = to_i2c_client(dev);
  56        struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  57        int retval = i2c_smbus_read_byte_data(client, sda->index);
  58
  59        if (retval < 0)
  60                return retval;
  61        return sprintf(buf, "%d000\n", retval);
  62}
  63
  64static ssize_t show_bit(struct device *dev,
  65                        struct device_attribute *attr, char *buf)
  66{
  67        struct i2c_client *client = to_i2c_client(dev);
  68        struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
  69        int retval = i2c_smbus_read_byte_data(client, sda->nr);
  70
  71        if (retval < 0)
  72                return retval;
  73        retval &= sda->index;
  74        return sprintf(buf, "%d\n", retval ? 1 : 0);
  75}
  76
  77static ssize_t store_temp(struct device *dev,
  78                struct device_attribute *attr, const char *buf, size_t count)
  79{
  80        struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  81        struct i2c_client *client = to_i2c_client(dev);
  82        unsigned long val;
  83        int retval;
  84
  85        if (kstrtoul(buf, 10, &val))
  86                return -EINVAL;
  87        retval = i2c_smbus_write_byte_data(client, sda->index,
  88                                        DIV_ROUND_CLOSEST(val, 1000));
  89        if (retval < 0)
  90                return retval;
  91        return count;
  92}
  93
  94static ssize_t store_bit(struct device *dev,
  95                struct device_attribute *attr, const char *buf, size_t count)
  96{
  97        struct i2c_client *client = to_i2c_client(dev);
  98        struct thermal_data *data = i2c_get_clientdata(client);
  99        struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
 100        unsigned long val;
 101        int retval;
 102
 103        if (kstrtoul(buf, 10, &val))
 104                return -EINVAL;
 105
 106        mutex_lock(&data->mutex);
 107        retval = i2c_smbus_read_byte_data(client, sda->nr);
 108        if (retval < 0)
 109                goto fail;
 110
 111        retval &= ~sda->index;
 112        if (val)
 113                retval |= sda->index;
 114
 115        retval = i2c_smbus_write_byte_data(client, sda->index, retval);
 116        if (retval == 0)
 117                retval = count;
 118fail:
 119        mutex_unlock(&data->mutex);
 120        return retval;
 121}
 122
 123static ssize_t show_hyst(struct device *dev,
 124                        struct device_attribute *attr, char *buf)
 125{
 126        struct i2c_client *client = to_i2c_client(dev);
 127        struct thermal_data *data = i2c_get_clientdata(client);
 128        struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 129        int retval;
 130        int hyst;
 131
 132        retval = i2c_smbus_read_byte_data(client, sda->index);
 133        if (retval < 0)
 134                return retval;
 135
 136        if (time_after(jiffies, data->hyst_valid)) {
 137                hyst = i2c_smbus_read_byte_data(client, 0x21);
 138                if (hyst < 0)
 139                        return retval;
 140                data->cached_hyst = hyst;
 141                data->hyst_valid = jiffies + HZ;
 142        }
 143        return sprintf(buf, "%d000\n", retval - data->cached_hyst);
 144}
 145
 146static ssize_t store_hyst(struct device *dev,
 147                struct device_attribute *attr, const char *buf, size_t count)
 148{
 149        struct i2c_client *client = to_i2c_client(dev);
 150        struct thermal_data *data = i2c_get_clientdata(client);
 151        struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 152        int retval;
 153        int hyst;
 154        unsigned long val;
 155
 156        if (kstrtoul(buf, 10, &val))
 157                return -EINVAL;
 158
 159        mutex_lock(&data->mutex);
 160        retval = i2c_smbus_read_byte_data(client, sda->index);
 161        if (retval < 0)
 162                goto fail;
 163
 164        hyst = val - retval * 1000;
 165        hyst = DIV_ROUND_CLOSEST(hyst, 1000);
 166        if (hyst < 0 || hyst > 255) {
 167                retval = -ERANGE;
 168                goto fail;
 169        }
 170
 171        retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
 172        if (retval == 0) {
 173                retval = count;
 174                data->cached_hyst = hyst;
 175                data->hyst_valid = jiffies + HZ;
 176        }
 177fail:
 178        mutex_unlock(&data->mutex);
 179        return retval;
 180}
 181
 182/*
 183 *      Sensors. We pass the actual i2c register to the methods.
 184 */
 185
 186static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
 187        show_temp, store_temp, 0x06);
 188static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
 189        show_temp, store_temp, 0x05);
 190static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
 191        show_temp, store_temp, 0x20);
 192static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
 193static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
 194        show_bit, NULL, 0x36, 0x01);
 195static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
 196        show_bit, NULL, 0x35, 0x01);
 197static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
 198        show_bit, NULL, 0x37, 0x01);
 199static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
 200        show_hyst, store_hyst, 0x20);
 201
 202static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
 203        show_temp, store_temp, 0x08);
 204static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
 205        show_temp, store_temp, 0x07);
 206static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
 207        show_temp, store_temp, 0x19);
 208static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
 209static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
 210        show_bit, NULL, 0x36, 0x02);
 211static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
 212        show_bit, NULL, 0x35, 0x02);
 213static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
 214        show_bit, NULL, 0x37, 0x02);
 215static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
 216        show_hyst, store_hyst, 0x19);
 217
 218static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
 219        show_temp, store_temp, 0x16);
 220static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
 221        show_temp, store_temp, 0x15);
 222static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
 223        show_temp, store_temp, 0x1A);
 224static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
 225static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
 226        show_bit, NULL, 0x36, 0x04);
 227static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
 228        show_bit, NULL, 0x35, 0x04);
 229static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
 230        show_bit, NULL, 0x37, 0x04);
 231static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
 232        show_hyst, store_hyst, 0x1A);
 233
 234static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
 235        show_bit, store_bit, 0x03, 0x40);
 236
 237static struct attribute *mid_att_thermal[] = {
 238        &sensor_dev_attr_temp1_min.dev_attr.attr,
 239        &sensor_dev_attr_temp1_max.dev_attr.attr,
 240        &sensor_dev_attr_temp1_crit.dev_attr.attr,
 241        &sensor_dev_attr_temp1_input.dev_attr.attr,
 242        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 243        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 244        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 245        &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 246        &sensor_dev_attr_temp2_min.dev_attr.attr,
 247        &sensor_dev_attr_temp2_max.dev_attr.attr,
 248        &sensor_dev_attr_temp2_crit.dev_attr.attr,
 249        &sensor_dev_attr_temp2_input.dev_attr.attr,
 250        &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 251        &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 252        &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 253        &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
 254        &sensor_dev_attr_temp3_min.dev_attr.attr,
 255        &sensor_dev_attr_temp3_max.dev_attr.attr,
 256        &sensor_dev_attr_temp3_crit.dev_attr.attr,
 257        &sensor_dev_attr_temp3_input.dev_attr.attr,
 258        &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
 259        &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 260        &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 261        &sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
 262        &sensor_dev_attr_power_state.dev_attr.attr,
 263        NULL
 264};
 265
 266static const struct attribute_group m_thermal_gr = {
 267        .attrs = mid_att_thermal
 268};
 269
 270static int emc1403_detect(struct i2c_client *client,
 271                        struct i2c_board_info *info)
 272{
 273        int id;
 274        /* Check if thermal chip is SMSC and EMC1403 or EMC1423 */
 275
 276        id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
 277        if (id != 0x5d)
 278                return -ENODEV;
 279
 280        id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
 281        switch (id) {
 282        case 0x21:
 283                strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
 284                break;
 285        case 0x23:
 286                strlcpy(info->type, "emc1423", I2C_NAME_SIZE);
 287                break;
 288        /*
 289         * Note: 0x25 is the 1404 which is very similar and this
 290         * driver could be extended
 291         */
 292        default:
 293                return -ENODEV;
 294        }
 295
 296        id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
 297        if (id != 0x01)
 298                return -ENODEV;
 299
 300        return 0;
 301}
 302
 303static int emc1403_probe(struct i2c_client *client,
 304                        const struct i2c_device_id *id)
 305{
 306        int res;
 307        struct thermal_data *data;
 308
 309        data = kzalloc(sizeof(struct thermal_data), GFP_KERNEL);
 310        if (data == NULL) {
 311                dev_warn(&client->dev, "out of memory");
 312                return -ENOMEM;
 313        }
 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                goto thermal_error1;
 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_error2;
 329        }
 330        dev_info(&client->dev, "EMC1403 Thermal chip found\n");
 331        return res;
 332
 333thermal_error2:
 334        sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
 335thermal_error1:
 336        kfree(data);
 337        return res;
 338}
 339
 340static int emc1403_remove(struct i2c_client *client)
 341{
 342        struct thermal_data *data = i2c_get_clientdata(client);
 343
 344        hwmon_device_unregister(data->hwmon_dev);
 345        sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
 346        kfree(data);
 347        return 0;
 348}
 349
 350static const unsigned short emc1403_address_list[] = {
 351        0x18, 0x29, 0x4c, 0x4d, I2C_CLIENT_END
 352};
 353
 354static const struct i2c_device_id emc1403_idtable[] = {
 355        { "emc1403", 0 },
 356        { "emc1423", 0 },
 357        { }
 358};
 359MODULE_DEVICE_TABLE(i2c, emc1403_idtable);
 360
 361static struct i2c_driver sensor_emc1403 = {
 362        .class = I2C_CLASS_HWMON,
 363        .driver = {
 364                .name = "emc1403",
 365        },
 366        .detect = emc1403_detect,
 367        .probe = emc1403_probe,
 368        .remove = emc1403_remove,
 369        .id_table = emc1403_idtable,
 370        .address_list = emc1403_address_list,
 371};
 372
 373module_i2c_driver(sensor_emc1403);
 374
 375MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
 376MODULE_DESCRIPTION("emc1403 Thermal Driver");
 377MODULE_LICENSE("GPL v2");
 378
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