hwmon: EMC1403 thermal sensor support
[pandora-kernel.git] / drivers / hwmon / emc1403.c
diff --git a/drivers/hwmon/emc1403.c b/drivers/hwmon/emc1403.c
new file mode 100644 (file)
index 0000000..0e4b564
--- /dev/null
@@ -0,0 +1,344 @@
+/*
+ * 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>
+
+#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 (strict_strtoul(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 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 (strict_strtoul(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 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,
+       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 */
+
+       id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
+       if (id != 0x5d)
+               return -ENODEV;
+
+       /* Note: 0x25 is the 1404 which is very similar and this
+          driver could be extended */
+       id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
+       if (id != 0x21)
+               return -ENODEV;
+
+       id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
+       if (id != 0x01)
+               return -ENODEV;
+
+       strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
+       return 0;
+}
+
+static int emc1403_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       int res;
+       struct thermal_data *data;
+
+       data = kzalloc(sizeof(struct thermal_data), GFP_KERNEL);
+       if (data == NULL) {
+               dev_warn(&client->dev, "out of memory");
+               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");
+               hwmon_device_unregister(data->hwmon_dev);
+               goto thermal_error1;
+       }
+       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_error2;
+       }
+       dev_info(&client->dev, "EMC1403 Thermal chip found\n");
+       return res;
+
+thermal_error2:
+       sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
+thermal_error1:
+       kfree(data);
+       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);
+       kfree(data);
+       return 0;
+}
+
+static const unsigned short emc1403_address_list[] = {
+       0x18, 0x2a, 0x4c, 0x4d, I2C_CLIENT_END
+};
+
+static const struct i2c_device_id emc1403_idtable[] = {
+       { "emc1403", 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,
+};
+
+static int __init sensor_emc1403_init(void)
+{
+       return i2c_add_driver(&sensor_emc1403);
+}
+
+static void  __exit sensor_emc1403_exit(void)
+{
+       i2c_del_driver(&sensor_emc1403);
+}
+
+module_init(sensor_emc1403_init);
+module_exit(sensor_emc1403_exit);
+
+MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
+MODULE_DESCRIPTION("emc1403 Thermal Driver");
+MODULE_LICENSE("GPL v2");