emc1403.c

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/*
 * emc1403.c - SMSC Thermal Driver
 *
 * Copyright (C) 2008 Intel Corp
 *
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * TODO
 *  -   cache alarm and critical limit registers
 *  -   add emc1404 support
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/sysfs.h>
#include <linux/mutex.h>
#include <linux/jiffies.h>

#define THERMAL_PID_REG     0xfd
#define THERMAL_SMSC_ID_REG 0xfe
#define THERMAL_REVISION_REG    0xff

struct thermal_data {
    struct device *hwmon_dev;
    struct mutex mutex;
    /*
     * Cache the hyst value so we don't keep re-reading it. In theory
     * we could cache it forever as nobody else should be writing it.
     */
    u8 cached_hyst;
    unsigned long hyst_valid;
};

static ssize_t show_temp(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
    int retval = i2c_smbus_read_byte_data(client, sda->index);

    if (retval < 0)
        return retval;
    return sprintf(buf, "%d000\n", retval);
}

static ssize_t show_bit(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
    int retval = i2c_smbus_read_byte_data(client, sda->nr);

    if (retval < 0)
        return retval;
    retval &= sda->index;
    return sprintf(buf, "%d\n", retval ? 1 : 0);
}

static ssize_t store_temp(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
    struct i2c_client *client = to_i2c_client(dev);
    unsigned long val;
    int retval;

    if (kstrtoul(buf, 10, &val))
        return -EINVAL;
    retval = i2c_smbus_write_byte_data(client, sda->index,
                    DIV_ROUND_CLOSEST(val, 1000));
    if (retval < 0)
        return retval;
    return count;
}

static ssize_t store_bit(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct thermal_data *data = i2c_get_clientdata(client);
    struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
    unsigned long val;
    int retval;

    if (kstrtoul(buf, 10, &val))
        return -EINVAL;

    mutex_lock(&data->mutex);
    retval = i2c_smbus_read_byte_data(client, sda->nr);
    if (retval < 0)
        goto fail;

    retval &= ~sda->index;
    if (val)
        retval |= sda->index;

    retval = i2c_smbus_write_byte_data(client, sda->index, retval);
    if (retval == 0)
        retval = count;
fail:
    mutex_unlock(&data->mutex);
    return retval;
}

static ssize_t show_hyst(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct thermal_data *data = i2c_get_clientdata(client);
    struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
    int retval;
    int hyst;

    retval = i2c_smbus_read_byte_data(client, sda->index);
    if (retval < 0)
        return retval;

    if (time_after(jiffies, data->hyst_valid)) {
        hyst = i2c_smbus_read_byte_data(client, 0x21);
        if (hyst < 0)
            return retval;
        data->cached_hyst = hyst;
        data->hyst_valid = jiffies + HZ;
    }
    return sprintf(buf, "%d000\n", retval - data->cached_hyst);
}

static ssize_t store_hyst(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct thermal_data *data = i2c_get_clientdata(client);
    struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
    int retval;
    int hyst;
    unsigned long val;

    if (kstrtoul(buf, 10, &val))
        return -EINVAL;

    mutex_lock(&data->mutex);
    retval = i2c_smbus_read_byte_data(client, sda->index);
    if (retval < 0)
        goto fail;

    hyst = val - retval * 1000;
    hyst = DIV_ROUND_CLOSEST(hyst, 1000);
    if (hyst < 0 || hyst > 255) {
        retval = -ERANGE;
        goto fail;
    }

    retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
    if (retval == 0) {
        retval = count;
        data->cached_hyst = hyst;
        data->hyst_valid = jiffies + HZ;
    }
fail:
    mutex_unlock(&data->mutex);
    return retval;
}

/*
 *  Sensors. We pass the actual i2c register to the methods.
 */

static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x06);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x05);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x20);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
    show_bit, NULL, 0x36, 0x01);
static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
    show_bit, NULL, 0x35, 0x01);
static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
    show_bit, NULL, 0x37, 0x01);
static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
    show_hyst, store_hyst, 0x20);

static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x08);
static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x07);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x19);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
    show_bit, NULL, 0x36, 0x02);
static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
    show_bit, NULL, 0x35, 0x02);
static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
    show_bit, NULL, 0x37, 0x02);
static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
    show_hyst, store_hyst, 0x19);

static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x16);
static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x15);
static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
    show_temp, store_temp, 0x1A);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
    show_bit, NULL, 0x36, 0x04);
static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
    show_bit, NULL, 0x35, 0x04);
static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
    show_bit, NULL, 0x37, 0x04);
static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
    show_hyst, store_hyst, 0x1A);

static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
    show_bit, store_bit, 0x03, 0x40);

static struct attribute *mid_att_thermal[] = {
    &sensor_dev_attr_temp1_min.dev_attr.attr,
    &sensor_dev_attr_temp1_max.dev_attr.attr,
    &sensor_dev_attr_temp1_crit.dev_attr.attr,
    &sensor_dev_attr_temp1_input.dev_attr.attr,
    &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
    &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
    &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
    &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
    &sensor_dev_attr_temp2_min.dev_attr.attr,
    &sensor_dev_attr_temp2_max.dev_attr.attr,
    &sensor_dev_attr_temp2_crit.dev_attr.attr,
    &sensor_dev_attr_temp2_input.dev_attr.attr,
    &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
    &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
    &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
    &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
    &sensor_dev_attr_temp3_min.dev_attr.attr,
    &sensor_dev_attr_temp3_max.dev_attr.attr,
    &sensor_dev_attr_temp3_crit.dev_attr.attr,
    &sensor_dev_attr_temp3_input.dev_attr.attr,
    &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
    &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
    &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
    &sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
    &sensor_dev_attr_power_state.dev_attr.attr,
    NULL
};

static const struct attribute_group m_thermal_gr = {
    .attrs = mid_att_thermal
};

static int emc1403_detect(struct i2c_client *client,
            struct i2c_board_info *info)
{
    int id;
    /* Check if thermal chip is SMSC and EMC1403 or EMC1423 */

    id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
    if (id != 0x5d)
        return -ENODEV;

    id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
    switch (id) {
    case 0x21:
        strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
        break;
    case 0x23:
        strlcpy(info->type, "emc1423", I2C_NAME_SIZE);
        break;
    /*
     * Note: 0x25 is the 1404 which is very similar and this
     * driver could be extended
     */
    default:
        return -ENODEV;
    }

    id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
    if (id != 0x01)
        return -ENODEV;

    return 0;
}

static int emc1403_probe(struct i2c_client *client,
            const struct i2c_device_id *id)
{
    int res;
    struct thermal_data *data;

    data = devm_kzalloc(&client->dev, sizeof(struct thermal_data),
                GFP_KERNEL);
    if (data == NULL)
        return -ENOMEM;

    i2c_set_clientdata(client, data);
    mutex_init(&data->mutex);
    data->hyst_valid = jiffies - 1;     /* Expired */

    res = sysfs_create_group(&client->dev.kobj, &m_thermal_gr);
    if (res) {
        dev_warn(&client->dev, "create group failed\n");
        return res;
    }
    data->hwmon_dev = hwmon_device_register(&client->dev);
    if (IS_ERR(data->hwmon_dev)) {
        res = PTR_ERR(data->hwmon_dev);
        dev_warn(&client->dev, "register hwmon dev failed\n");
        goto thermal_error;
    }
    dev_info(&client->dev, "EMC1403 Thermal chip found\n");
    return 0;

thermal_error:
    sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
    return res;
}

static int emc1403_remove(struct i2c_client *client)
{
    struct thermal_data *data = i2c_get_clientdata(client);

    hwmon_device_unregister(data->hwmon_dev);
    sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
    return 0;
}

static const unsigned short emc1403_address_list[] = {
    0x18, 0x29, 0x4c, 0x4d, I2C_CLIENT_END
};

static const struct i2c_device_id emc1403_idtable[] = {
    { "emc1403", 0 },
    { "emc1423", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, emc1403_idtable);

static struct i2c_driver sensor_emc1403 = {
    .class = I2C_CLASS_HWMON,
    .driver = {
        .name = "emc1403",
    },
    .detect = emc1403_detect,
    .probe = emc1403_probe,
    .remove = emc1403_remove,
    .id_table = emc1403_idtable,
    .address_list = emc1403_address_list,
};

module_i2c_driver(sensor_emc1403);

MODULE_AUTHOR("Kalhan Trisal <[email protected]");
MODULE_DESCRIPTION("emc1403 Thermal Driver");
MODULE_LICENSE("GPL v2");