--- /dev/null
+/*
+ * Driver for +/-1 degree C, SMBus-Compatible Remote/Local Temperature Sensor
+ * with Overtemperature Alarm
+ *
+ * Copyright (C) 2011 AppearTV AS
+ *
+ * Derived from:
+ *
+ * Based on the max1619 driver.
+ * Copyright (C) 2003-2004 Alexey Fisher <fishor@mail.ru>
+ * Jean Delvare <khali@linux-fr.org>
+ *
+ * The MAX6642 is a sensor chip made by Maxim.
+ * It reports up to two temperatures (its own plus up to
+ * one external one). Complete datasheet can be
+ * obtained from Maxim's website at:
+ * http://datasheets.maxim-ic.com/en/ds/MAX6642.pdf
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+
+static const unsigned short normal_i2c[] = {
+ 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
+
+/*
+ * The MAX6642 registers
+ */
+
+#define MAX6642_REG_R_MAN_ID 0xFE
+#define MAX6642_REG_R_CONFIG 0x03
+#define MAX6642_REG_W_CONFIG 0x09
+#define MAX6642_REG_R_STATUS 0x02
+#define MAX6642_REG_R_LOCAL_TEMP 0x00
+#define MAX6642_REG_R_LOCAL_TEMPL 0x11
+#define MAX6642_REG_R_LOCAL_HIGH 0x05
+#define MAX6642_REG_W_LOCAL_HIGH 0x0B
+#define MAX6642_REG_R_REMOTE_TEMP 0x01
+#define MAX6642_REG_R_REMOTE_TEMPL 0x10
+#define MAX6642_REG_R_REMOTE_HIGH 0x07
+#define MAX6642_REG_W_REMOTE_HIGH 0x0D
+
+/*
+ * Conversions
+ */
+
+static int temp_from_reg10(int val)
+{
+ return val * 250;
+}
+
+static int temp_from_reg(int val)
+{
+ return val * 1000;
+}
+
+static int temp_to_reg(int val)
+{
+ return val / 1000;
+}
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct max6642_data {
+ struct device *hwmon_dev;
+ struct mutex update_lock;
+ bool valid; /* zero until following fields are valid */
+ unsigned long last_updated; /* in jiffies */
+
+ /* registers values */
+ u16 temp_input[2]; /* local/remote */
+ u16 temp_high[2]; /* local/remote */
+ u8 alarms;
+};
+
+/*
+ * Real code
+ */
+
+static void max6642_init_client(struct i2c_client *client)
+{
+ u8 config;
+ struct max6642_data *data = i2c_get_clientdata(client);
+
+ /*
+ * Start the conversions.
+ */
+ config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG);
+ if (config & 0x40)
+ i2c_smbus_write_byte_data(client, MAX6642_REG_W_CONFIG,
+ config & 0xBF); /* run */
+
+ data->temp_high[0] = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_LOCAL_HIGH);
+ data->temp_high[1] = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_REMOTE_HIGH);
+}
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int max6642_detect(struct i2c_client *client,
+ struct i2c_board_info *info)
+{
+ struct i2c_adapter *adapter = client->adapter;
+ u8 reg_config, reg_status, man_id;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+ return -ENODEV;
+
+ /* identification */
+ man_id = i2c_smbus_read_byte_data(client, MAX6642_REG_R_MAN_ID);
+ if (man_id != 0x4D)
+ return -ENODEV;
+
+ /*
+ * We read the config and status register, the 4 lower bits in the
+ * config register should be zero and bit 5, 3, 1 and 0 should be
+ * zero in the status register.
+ */
+ reg_config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG);
+ reg_status = i2c_smbus_read_byte_data(client, MAX6642_REG_R_STATUS);
+ if (((reg_config & 0x0f) != 0x00) ||
+ ((reg_status & 0x2b) != 0x00))
+ return -ENODEV;
+
+ strlcpy(info->type, "max6642", I2C_NAME_SIZE);
+
+ return 0;
+}
+
+static struct max6642_data *max6642_update_device(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct max6642_data *data = i2c_get_clientdata(client);
+ u16 val, tmp;
+
+ mutex_lock(&data->update_lock);
+
+ if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+ dev_dbg(&client->dev, "Updating max6642 data.\n");
+ val = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_LOCAL_TEMPL);
+ tmp = (val >> 6) & 3;
+ val = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_LOCAL_TEMP);
+ val = (val << 2) | tmp;
+ data->temp_input[0] = val;
+ val = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_REMOTE_TEMPL);
+ tmp = (val >> 6) & 3;
+ val = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_REMOTE_TEMP);
+ val = (val << 2) | tmp;
+ data->temp_input[1] = val;
+ data->alarms = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_STATUS);
+
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+
+ mutex_unlock(&data->update_lock);
+
+ return data;
+}
+
+/*
+ * Sysfs stuff
+ */
+
+static ssize_t show_temp_max10(struct device *dev,
+ struct device_attribute *dev_attr, char *buf)
+{
+ struct max6642_data *data = max6642_update_device(dev);
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+
+ return sprintf(buf, "%d\n",
+ temp_from_reg10(data->temp_input[attr->index]));
+}
+
+static ssize_t show_temp_max(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct max6642_data *data = max6642_update_device(dev);
+ struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
+
+ return sprintf(buf, "%d\n", temp_from_reg(data->temp_high[attr2->nr]));
+}
+
+static ssize_t set_temp_max(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long val;
+ int err;
+ struct i2c_client *client = to_i2c_client(dev);
+ struct max6642_data *data = i2c_get_clientdata(client);
+ struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
+
+ err = strict_strtoul(buf, 10, &val);
+ if (err < 0)
+ return err;
+
+ mutex_lock(&data->update_lock);
+ data->temp_high[attr2->nr] = SENSORS_LIMIT(temp_to_reg(val), 0, 255);
+ i2c_smbus_write_byte_data(client, attr2->index,
+ data->temp_high[attr2->nr]);
+ mutex_unlock(&data->update_lock);
+ return count;
+}
+
+static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ int bitnr = to_sensor_dev_attr(attr)->index;
+ struct max6642_data *data = max6642_update_device(dev);
+ return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_max10, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_max10, NULL, 1);
+static SENSOR_DEVICE_ATTR_2(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
+ set_temp_max, 0, MAX6642_REG_W_LOCAL_HIGH);
+static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp_max,
+ set_temp_max, 1, MAX6642_REG_W_REMOTE_HIGH);
+static SENSOR_DEVICE_ATTR(temp_fault, S_IRUGO, show_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
+static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
+
+static struct attribute *max6642_attributes[] = {
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ &sensor_dev_attr_temp2_input.dev_attr.attr,
+ &sensor_dev_attr_temp1_max.dev_attr.attr,
+ &sensor_dev_attr_temp2_max.dev_attr.attr,
+
+ &sensor_dev_attr_temp_fault.dev_attr.attr,
+ &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+ &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group max6642_group = {
+ .attrs = max6642_attributes,
+};
+
+static int max6642_probe(struct i2c_client *new_client,
+ const struct i2c_device_id *id)
+{
+ struct max6642_data *data;
+ int err;
+
+ data = kzalloc(sizeof(struct max6642_data), GFP_KERNEL);
+ if (!data) {
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ i2c_set_clientdata(new_client, data);
+ mutex_init(&data->update_lock);
+
+ /* Initialize the MAX6642 chip */
+ max6642_init_client(new_client);
+
+ /* Register sysfs hooks */
+ err = sysfs_create_group(&new_client->dev.kobj, &max6642_group);
+ if (err)
+ goto exit_free;
+
+ data->hwmon_dev = hwmon_device_register(&new_client->dev);
+ if (IS_ERR(data->hwmon_dev)) {
+ err = PTR_ERR(data->hwmon_dev);
+ goto exit_remove_files;
+ }
+
+ return 0;
+
+exit_remove_files:
+ sysfs_remove_group(&new_client->dev.kobj, &max6642_group);
+exit_free:
+ kfree(data);
+exit:
+ return err;
+}
+
+static int max6642_remove(struct i2c_client *client)
+{
+ struct max6642_data *data = i2c_get_clientdata(client);
+
+ hwmon_device_unregister(data->hwmon_dev);
+ sysfs_remove_group(&client->dev.kobj, &max6642_group);
+
+ kfree(data);
+ return 0;
+}
+
+/*
+ * Driver data (common to all clients)
+ */
+
+static const struct i2c_device_id max6642_id[] = {
+ { "max6642", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max6642_id);
+
+static struct i2c_driver max6642_driver = {
+ .class = I2C_CLASS_HWMON,
+ .driver = {
+ .name = "max6642",
+ },
+ .probe = max6642_probe,
+ .remove = max6642_remove,
+ .id_table = max6642_id,
+ .detect = max6642_detect,
+ .address_list = normal_i2c,
+};
+
+static int __init max6642_init(void)
+{
+ return i2c_add_driver(&max6642_driver);
+}
+
+static void __exit max6642_exit(void)
+{
+ i2c_del_driver(&max6642_driver);
+}
+
+MODULE_AUTHOR("Per Dalen <per.dalen@appeartv.com>");
+MODULE_DESCRIPTION("MAX6642 sensor driver");
+MODULE_LICENSE("GPL");
+
+module_init(max6642_init);
+module_exit(max6642_exit);
git.openpandora.org / pandora-kernel.git / commitdiff