[PATCH] I2C: add fscpos chip driver

This patch against 2.6.11-rc1 contains a driver for fscpos sensors.
Signed-off-by: Stefan Ott <stefan@desire.ch>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/i2c/chips/Kconfig

@@ -84,6 +84,17 @@ config SENSORS_FSCHER
 	  This driver can also be built as a module.  If so, the module
 	  will be called fscher.
 
+config SENSORS_FSCPOS
+	tristate "FSC Poseidon"
+	depends on I2C && EXPERIMENTAL
+	select I2C_SENSOR
+	help
+	  If you say yes here you get support for Fujitsu Siemens
+	  Computers Poseidon sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called fscpos.
+
 config SENSORS_GL518SM
 	tristate "Genesys Logic GL518SM"
 	depends on I2C && EXPERIMENTAL

drivers/i2c/chips/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_SENSORS_ADM1031)	+= adm1031.o
 obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o
 obj-$(CONFIG_SENSORS_EEPROM)	+= eeprom.o
 obj-$(CONFIG_SENSORS_FSCHER)	+= fscher.o
+obj-$(CONFIG_SENSORS_FSCPOS)	+= fscpos.o
 obj-$(CONFIG_SENSORS_GL518SM)	+= gl518sm.o
 obj-$(CONFIG_SENSORS_IT87)	+= it87.o
 obj-$(CONFIG_SENSORS_LM63)	+= lm63.o

drivers/i2c/chips/fscpos.c

+/*
+	fscpos.c - Kernel module for hardware monitoring with FSC Poseidon chips
+	Copyright (C) 2004, 2005 Stefan Ott <stefan@desire.ch>
+
+	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.
+*/
+
+/*
+	fujitsu siemens poseidon chip,
+	module based on the old fscpos module by Hermann Jung <hej@odn.de> and
+	the fscher module by Reinhard Nissl <rnissl@gmx.de>
+
+	original module based on lm80.c
+	Copyright (C) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
+	and Philip Edelbrock <phil@netroedge.com>
+
+	Thanks to Jean Delvare for reviewing my code and suggesting a lot of
+	improvements.
+*/
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/i2c-sensor.h>
+#include <linux/init.h>
+
+/*
+ * Addresses to scan
+ */
+static unsigned short normal_i2c[] = { 0x73, I2C_CLIENT_END };
+static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
+
+/*
+ * Insmod parameters
+ */
+SENSORS_INSMOD_1(fscpos);
+
+/*
+ * The FSCPOS registers
+ */
+
+#define DEBUG
+
+/* chip identification */
+#define FSCPOS_REG_IDENT_0		0x00
+#define FSCPOS_REG_IDENT_1		0x01
+#define FSCPOS_REG_IDENT_2		0x02
+#define FSCPOS_REG_REVISION		0x03
+
+/* global control and status */
+#define FSCPOS_REG_EVENT_STATE		0x04
+#define FSCPOS_REG_CONTROL		0x05
+
+/* watchdog */
+#define FSCPOS_REG_WDOG_PRESET		0x28
+#define FSCPOS_REG_WDOG_STATE		0x23
+#define FSCPOS_REG_WDOG_CONTROL		0x21
+
+/* voltages */
+#define FSCPOS_REG_VOLT_12		0x45
+#define FSCPOS_REG_VOLT_5		0x42
+#define FSCPOS_REG_VOLT_BATT		0x48
+
+/* fans - the chip does not support minimum speed for fan2 */
+static u8 FSCPOS_REG_PWM[] = { 0x55, 0x65 };
+static u8 FSCPOS_REG_FAN_ACT[] = { 0x0e, 0x6b, 0xab };
+static u8 FSCPOS_REG_FAN_STATE[] = { 0x0d, 0x62, 0xa2 };
+static u8 FSCPOS_REG_FAN_RIPPLE[] = { 0x0f, 0x6f, 0xaf };
+
+/* temperatures */
+static u8 FSCPOS_REG_TEMP_ACT[] = { 0x64, 0x32, 0x35 };
+static u8 FSCPOS_REG_TEMP_STATE[] = { 0x71, 0x81, 0x91 };
+
+/*
+ * Functions declaration
+ */
+static int fscpos_attach_adapter(struct i2c_adapter *adapter);
+static int fscpos_detect(struct i2c_adapter *adapter, int address, int kind);
+static int fscpos_detach_client(struct i2c_client *client);
+
+static int fscpos_read_value(struct i2c_client *client, u8 register);
+static int fscpos_write_value(struct i2c_client *client, u8 register, u8 value);
+static struct fscpos_data *fscpos_update_device(struct device *dev);
+static void fscpos_init_client(struct i2c_client *client);
+
+static void reset_fan_alarm(struct i2c_client *client, int nr);
+
+/*
+ * Driver data (common to all clients)
+ */
+static struct i2c_driver fscpos_driver = {
+	.owner		= THIS_MODULE,
+	.name		= "fscpos",
+	.id		= I2C_DRIVERID_FSCPOS,
+	.flags		= I2C_DF_NOTIFY,
+	.attach_adapter	= fscpos_attach_adapter,
+	.detach_client	= fscpos_detach_client,
+};
+
+/*
+ * Client data (each client gets its own)
+ */
+struct fscpos_data {
+	struct i2c_client client;
+	struct semaphore update_lock;
+	char valid; 		/* 0 until following fields are valid */
+	unsigned long last_updated;	/* In jiffies */
+
+	/* register values */
+	u8 revision;		/* revision of chip */
+	u8 global_event;	/* global event status */
+	u8 global_control;	/* global control register */
+	u8 wdog_control;	/* watchdog control */
+	u8 wdog_state;		/* watchdog status */
+	u8 wdog_preset;		/* watchdog preset */
+	u8 volt[3];		/* 12, 5, battery current */
+	u8 temp_act[3];		/* temperature */
+	u8 temp_status[3];	/* status of sensor */
+	u8 fan_act[3];		/* fans revolutions per second */
+	u8 fan_status[3];	/* fan status */
+	u8 pwm[2];		/* fan min value for rps */
+	u8 fan_ripple[3];	/* divider for rps */
+};
+
+/* Temperature */
+#define TEMP_FROM_REG(val)	(((val) - 128) * 1000)
+
+static ssize_t show_temp_input(struct fscpos_data *data, char *buf, int nr)
+{
+	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_act[nr - 1]));
+}
+
+static ssize_t show_temp_status(struct fscpos_data *data, char *buf, int nr)
+{
+	/* bits 2..7 reserved => mask with 0x03 */
+	return sprintf(buf, "%u\n", data->temp_status[nr - 1] & 0x03);
+}
+
+static ssize_t show_temp_reset(struct fscpos_data *data, char *buf, int nr)
+{
+	return sprintf(buf, "1\n");
+}
+
+static ssize_t set_temp_reset(struct i2c_client *client, struct fscpos_data
+			*data, const char *buf,	size_t count, int nr, int reg)
+{
+	unsigned long v = simple_strtoul(buf, NULL, 10);
+	if (v != 1) {
+		dev_err(&client->dev, "temp_reset value %ld not supported. "
+					"Use 1 to reset the alarm!\n", v);
+		return -EINVAL;
+	}
+
+	dev_info(&client->dev, "You used the temp_reset feature which has not "
+				"been proplerly tested. Please report your "
+				"experience to the module author.\n");
+
+	/* Supported value: 2 (clears the status) */
+	fscpos_write_value(client, FSCPOS_REG_TEMP_STATE[nr], 2);
+	return count;
+}
+
+/* Fans */
+#define RPM_FROM_REG(val)	((val) * 60)
+
+static ssize_t show_fan_status(struct fscpos_data *data, char *buf, int nr)
+{
+	/* bits 0..1, 3..7 reserved => mask with 0x04 */
+	return sprintf(buf, "%u\n", data->fan_status[nr - 1] & 0x04);
+}
+
+static ssize_t show_fan_input(struct fscpos_data *data, char *buf, int nr)
+{
+	return sprintf(buf, "%u\n", RPM_FROM_REG(data->fan_act[nr - 1]));
+}
+
+static ssize_t show_fan_ripple(struct fscpos_data *data, char *buf, int nr)
+{
+	/* bits 2..7 reserved => mask with 0x03 */
+	return sprintf(buf, "%u\n", data->fan_ripple[nr - 1] & 0x03);
+}
+
+static ssize_t set_fan_ripple(struct i2c_client *client, struct fscpos_data
+			*data, const char *buf,	size_t count, int nr, int reg)
+{
+	/* supported values: 2, 4, 8 */
+	unsigned long v = simple_strtoul(buf, NULL, 10);
+
+	switch (v) {
+		case 2: v = 1; break;
+		case 4: v = 2; break;
+		case 8: v = 3; break;
+	default:
+		dev_err(&client->dev, "fan_ripple value %ld not supported. "
+					"Must be one of 2, 4 or 8!\n", v);
+		return -EINVAL;
+	}
+	
+	/* bits 2..7 reserved => mask with 0x03 */
+	data->fan_ripple[nr - 1] &= ~0x03;
+	data->fan_ripple[nr - 1] |= v;
+	
+	fscpos_write_value(client, reg, data->fan_ripple[nr - 1]);
+	return count;
+}
+
+static ssize_t show_pwm(struct fscpos_data *data, char *buf, int nr)
+{
+	return sprintf(buf, "%u\n", data->pwm[nr - 1]);
+}
+
+static ssize_t set_pwm(struct i2c_client *client, struct fscpos_data *data,
+				const char *buf, size_t count, int nr, int reg)
+{
+	unsigned long v = simple_strtoul(buf, NULL, 10);
+
+	/* Range: 0..255 */
+	if (v < 0) v = 0;
+	if (v > 255) v = 255;
+
+	data->pwm[nr - 1] = v;
+	fscpos_write_value(client, reg, data->pwm[nr - 1]);
+	return count;
+}
+
+static void reset_fan_alarm(struct i2c_client *client, int nr)
+{
+	fscpos_write_value(client, FSCPOS_REG_FAN_STATE[nr], 4);
+}
+
+/* Volts */
+#define VOLT_FROM_REG(val, mult)	((val) * (mult) / 255)
+
+static ssize_t show_volt_12(struct device *dev, char *buf)
+{
+	struct fscpos_data *data = fscpos_update_device(dev);
+	return sprintf(buf, "%u\n", VOLT_FROM_REG(data->volt[0], 1420));
+}
+
+static ssize_t show_volt_5(struct device *dev, char *buf)
+{
+	struct fscpos_data *data = fscpos_update_device(dev);
+	return sprintf(buf, "%u\n", VOLT_FROM_REG(data->volt[1], 660));
+}
+
+static ssize_t show_volt_batt(struct device *dev, char *buf)
+{
+	struct fscpos_data *data = fscpos_update_device(dev);
+	return sprintf(buf, "%u\n", VOLT_FROM_REG(data->volt[2], 330));
+}
+
+/* Watchdog */
+static ssize_t show_wdog_control(struct fscpos_data *data, char *buf)
+{
+	/* bits 0..3 reserved, bit 6 write only => mask with 0xb0 */
+	return sprintf(buf, "%u\n", data->wdog_control & 0xb0);
+}
+
+static ssize_t set_wdog_control(struct i2c_client *client, struct fscpos_data
+				*data, const char *buf,	size_t count, int reg)
+{
+	/* bits 0..3 reserved => mask with 0xf0 */
+	unsigned long v = simple_strtoul(buf, NULL, 10) & 0xf0;
+	data->wdog_control &= ~0xf0;
+	data->wdog_control |= v;
+	
+	fscpos_write_value(client, reg, data->wdog_control);
+	return count;
+}
+
+static ssize_t show_wdog_state(struct fscpos_data *data, char *buf)
+{
+	/* bits 0, 2..7 reserved => mask with 0x02 */
+	return sprintf(buf, "%u\n", data->wdog_state & 0x02);
+}
+
+static ssize_t set_wdog_state(struct i2c_client *client, struct fscpos_data
+				*data, const char *buf, size_t count, int reg)
+{
+	unsigned long v = simple_strtoul(buf, NULL, 10) & 0x02;
+
+	/* Valid values: 2 (clear) */
+	if (v != 2) {
+		dev_err(&client->dev, "wdog_state value %ld not supported. "
+					"Must be 2 to clear the state!\n", v);
+		return -EINVAL;
+	}
+
+	data->wdog_state &= ~v;
+	
+	fscpos_write_value(client, reg, v);
+	return count;
+}
+
+static ssize_t show_wdog_preset(struct fscpos_data *data, char *buf)
+{
+	return sprintf(buf, "%u\n", data->wdog_preset);
+}
+
+static ssize_t set_wdog_preset(struct i2c_client *client, struct fscpos_data
+				*data, const char *buf,	size_t count, int reg)
+{
+	data->wdog_preset = simple_strtoul(buf, NULL, 10) & 0xff;
+	
+	fscpos_write_value(client, reg, data->wdog_preset);
+	return count;
+}
+
+/* Event */
+static ssize_t show_event(struct device *dev, char *buf)
+{
+	/* bits 5..7 reserved => mask with 0x1f */
+	struct fscpos_data *data = fscpos_update_device(dev);
+	return sprintf(buf, "%u\n", data->global_event & 0x9b);
+}
+
+/*
+ * Sysfs stuff
+ */
+#define create_getter(kind, sub) \
+	static ssize_t sysfs_show_##kind##sub(struct device *dev, char *buf) \
+	{ \
+		struct fscpos_data *data = fscpos_update_device(dev); \
+		return show_##kind##sub(data, buf); \
+	}
+
+#define create_getter_n(kind, offset, sub) \
+	static ssize_t sysfs_show_##kind##offset##sub(struct device *dev, char\
+								 	*buf) \
+	{ \
+		struct fscpos_data *data = fscpos_update_device(dev); \
+		return show_##kind##sub(data, buf, offset); \
+	}
+
+#define create_setter(kind, sub, reg) \
+	static ssize_t sysfs_set_##kind##sub (struct device *dev, const char \
+							*buf, size_t count) \
+	{ \
+		struct i2c_client *client = to_i2c_client(dev); \
+		struct fscpos_data *data = i2c_get_clientdata(client); \
+		return set_##kind##sub(client, data, buf, count, reg); \
+	}
+
+#define create_setter_n(kind, offset, sub, reg) \
+	static ssize_t sysfs_set_##kind##offset##sub (struct device *dev, \
+					const char *buf, size_t count) \
+	{ \
+		struct i2c_client *client = to_i2c_client(dev); \
+		struct fscpos_data *data = i2c_get_clientdata(client); \
+		return set_##kind##sub(client, data, buf, count, offset, reg);\
+	}
+
+#define create_sysfs_device_ro(kind, sub, offset) \
+	static DEVICE_ATTR(kind##offset##sub, S_IRUGO, \
+					sysfs_show_##kind##offset##sub, NULL);
+
+#define create_sysfs_device_rw(kind, sub, offset) \
+	static DEVICE_ATTR(kind##offset##sub, S_IRUGO | S_IWUSR, \
+		sysfs_show_##kind##offset##sub, sysfs_set_##kind##offset##sub);
+
+#define sysfs_ro_n(kind, sub, offset) \
+	create_getter_n(kind, offset, sub); \
+	create_sysfs_device_ro(kind, sub, offset);
+
+#define sysfs_rw_n(kind, sub, offset, reg) \
+	create_getter_n(kind, offset, sub); \
+	create_setter_n(kind, offset, sub, reg); \
+	create_sysfs_device_rw(kind, sub, offset);
+
+#define sysfs_rw(kind, sub, reg) \
+	create_getter(kind, sub); \
+	create_setter(kind, sub, reg); \
+	create_sysfs_device_rw(kind, sub,);
+
+#define sysfs_fan_with_min(offset, reg_status, reg_ripple, reg_min) \
+	sysfs_fan(offset, reg_status, reg_ripple); \
+	sysfs_rw_n(pwm,, offset, reg_min);
+
+#define sysfs_fan(offset, reg_status, reg_ripple) \
+	sysfs_ro_n(fan, _input, offset); \
+	sysfs_ro_n(fan, _status, offset); \
+	sysfs_rw_n(fan, _ripple, offset, reg_ripple);
+
+#define sysfs_temp(offset, reg_status) \
+	sysfs_ro_n(temp, _input, offset); \
+	sysfs_ro_n(temp, _status, offset); \
+	sysfs_rw_n(temp, _reset, offset, reg_status);
+
+#define sysfs_watchdog(reg_wdog_preset, reg_wdog_state, reg_wdog_control) \
+	sysfs_rw(wdog, _control, reg_wdog_control); \
+	sysfs_rw(wdog, _preset, reg_wdog_preset); \
+	sysfs_rw(wdog, _state, reg_wdog_state);
+
+sysfs_fan_with_min(1, FSCPOS_REG_FAN_STATE[0], FSCPOS_REG_FAN_RIPPLE[0],
+							FSCPOS_REG_PWM[0]);
+sysfs_fan_with_min(2, FSCPOS_REG_FAN_STATE[1], FSCPOS_REG_FAN_RIPPLE[1],
+							FSCPOS_REG_PWM[1]);
+sysfs_fan(3, FSCPOS_REG_FAN_STATE[2], FSCPOS_REG_FAN_RIPPLE[2]);
+
+sysfs_temp(1, FSCPOS_REG_TEMP_STATE[0]);
+sysfs_temp(2, FSCPOS_REG_TEMP_STATE[1]);
+sysfs_temp(3, FSCPOS_REG_TEMP_STATE[2]);
+
+sysfs_watchdog(FSCPOS_REG_WDOG_PRESET, FSCPOS_REG_WDOG_STATE,
+						FSCPOS_REG_WDOG_CONTROL);
+
+static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);
+static DEVICE_ATTR(in0_input, S_IRUGO, show_volt_12, NULL);
+static DEVICE_ATTR(in1_input, S_IRUGO, show_volt_5, NULL);
+static DEVICE_ATTR(in2_input, S_IRUGO, show_volt_batt, NULL);
+
+static int fscpos_attach_adapter(struct i2c_adapter *adapter)
+{
+	if (!(adapter->class & I2C_CLASS_HWMON))
+		return 0;
+	return i2c_detect(adapter, &addr_data, fscpos_detect);
+}
+
+int fscpos_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+	struct i2c_client *new_client;
+	struct fscpos_data *data;
+	int err = 0;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		goto exit;
+
+	/*
+	 * OK. For now, we presume we have a valid client. We now create the
+	 * client structure, even though we cannot fill it completely yet.
+	 * But it allows us to access fscpos_{read,write}_value.
+	 */
+
+	if (!(data = kmalloc(sizeof(struct fscpos_data), GFP_KERNEL))) {
+		err = -ENOMEM;
+		goto exit;
+	}
+	memset(data, 0, sizeof(struct fscpos_data));
+
+	new_client = &data->client;
+	i2c_set_clientdata(new_client, data);
+	new_client->addr = address;
+	new_client->adapter = adapter;
+	new_client->driver = &fscpos_driver;
+	new_client->flags = 0;
+
+	/* Do the remaining detection unless force or force_fscpos parameter */
+	if (kind < 0) {
+		if ((fscpos_read_value(new_client, FSCPOS_REG_IDENT_0)
+			!= 0x50) /* 'P' */
+		|| (fscpos_read_value(new_client, FSCPOS_REG_IDENT_1)
+			!= 0x45) /* 'E' */
+		|| (fscpos_read_value(new_client, FSCPOS_REG_IDENT_2)
+			!= 0x47))/* 'G' */
+		{
+			dev_dbg(&new_client->dev, "fscpos detection failed\n");
+			goto exit_free;
+		}
+	}
+
+	/* Fill in the remaining client fields and put it in the global list */
+	strlcpy(new_client->name, "fscpos", I2C_NAME_SIZE);
+
+	data->valid = 0;
+	init_MUTEX(&data->update_lock);
+
+	/* Tell the I2C layer a new client has arrived */
+	if ((err = i2c_attach_client(new_client)))
+		goto exit_free;
+
+	/* Inizialize the fscpos chip */
+	fscpos_init_client(new_client);
+
+	/* Announce that the chip was found */
+	dev_info(&new_client->dev, "Found fscpos chip, rev %u\n", data->revision);
+
+	/* Register sysfs hooks */
+	device_create_file(&new_client->dev, &dev_attr_event);
+	device_create_file(&new_client->dev, &dev_attr_in0_input);
+	device_create_file(&new_client->dev, &dev_attr_in1_input);
+	device_create_file(&new_client->dev, &dev_attr_in2_input);
+	device_create_file(&new_client->dev, &dev_attr_wdog_control);
+	device_create_file(&new_client->dev, &dev_attr_wdog_preset);
+	device_create_file(&new_client->dev, &dev_attr_wdog_state);
+	device_create_file(&new_client->dev, &dev_attr_temp1_input);
+	device_create_file(&new_client->dev, &dev_attr_temp1_status);
+	device_create_file(&new_client->dev, &dev_attr_temp1_reset);
+	device_create_file(&new_client->dev, &dev_attr_temp2_input);
+	device_create_file(&new_client->dev, &dev_attr_temp2_status);
+	device_create_file(&new_client->dev, &dev_attr_temp2_reset);
+	device_create_file(&new_client->dev, &dev_attr_temp3_input);
+	device_create_file(&new_client->dev, &dev_attr_temp3_status);
+	device_create_file(&new_client->dev, &dev_attr_temp3_reset);
+	device_create_file(&new_client->dev, &dev_attr_fan1_input);
+	device_create_file(&new_client->dev, &dev_attr_fan1_status);
+	device_create_file(&new_client->dev, &dev_attr_fan1_ripple);
+	device_create_file(&new_client->dev, &dev_attr_pwm1);
+	device_create_file(&new_client->dev, &dev_attr_fan2_input);
+	device_create_file(&new_client->dev, &dev_attr_fan2_status);
+	device_create_file(&new_client->dev, &dev_attr_fan2_ripple);
+	device_create_file(&new_client->dev, &dev_attr_pwm2);
+	device_create_file(&new_client->dev, &dev_attr_fan3_input);
+	device_create_file(&new_client->dev, &dev_attr_fan3_status);
+	device_create_file(&new_client->dev, &dev_attr_fan3_ripple);
+
+	return 0;
+
+exit_free:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int fscpos_detach_client(struct i2c_client *client)
+{
+	int err;
+
+	if ((err = i2c_detach_client(client))) {
+		dev_err(&client->dev, "Client deregistration failed, client"
+							" not detached.\n");
+		return err;
+	}
+	kfree(i2c_get_clientdata(client));
+	return 0;
+}
+
+static int fscpos_read_value(struct i2c_client *client, u8 reg)
+{
+	dev_dbg(&client->dev, "Read reg 0x%02x\n", reg);
+	return i2c_smbus_read_byte_data(client, reg);
+}
+
+static int fscpos_write_value(struct i2c_client *client, u8 reg, u8 value)
+{
+	dev_dbg(&client->dev, "Write reg 0x%02x, val 0x%02x\n", reg, value);
+	return i2c_smbus_write_byte_data(client, reg, value);
+}
+
+/* Called when we have found a new FSCPOS chip */
+static void fscpos_init_client(struct i2c_client *client)
+{
+	struct fscpos_data *data = i2c_get_clientdata(client);
+
+	/* read revision from chip */
+	data->revision = fscpos_read_value(client, FSCPOS_REG_REVISION);
+}
+
+static struct fscpos_data *fscpos_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct fscpos_data *data = i2c_get_clientdata(client);
+
+	down(&data->update_lock);
+
+	if ((jiffies - data->last_updated > 2 * HZ) ||
+			(jiffies < data->last_updated) || !data->valid) {
+
+		dev_dbg(&client->dev, "Starting fscpos update\n");
+
+		int i;
+		for (i = 0; i < 3; i++) {
+			data->temp_act[i] = fscpos_read_value(client,
+						FSCPOS_REG_TEMP_ACT[i]);
+			data->temp_status[i] = fscpos_read_value(client,
+						FSCPOS_REG_TEMP_STATE[i]);
+			data->fan_act[i] = fscpos_read_value(client,
+						FSCPOS_REG_FAN_ACT[i]);
+			data->fan_status[i] = fscpos_read_value(client,
+						FSCPOS_REG_FAN_STATE[i]);
+			data->fan_ripple[i] = fscpos_read_value(client,
+						FSCPOS_REG_FAN_RIPPLE[i]);
+			if (i < 2) {
+				/* fan2_min is not supported by the chip */
+				data->pwm[i] = fscpos_read_value(client,
+							FSCPOS_REG_PWM[i]);
+			}
+			/* reset fan status if speed is back to > 0 */
+			if (data->fan_status[i] != 0 && data->fan_act[i] > 0) {
+				reset_fan_alarm(client, i);
+			}
+		}
+
+		data->volt[0] = fscpos_read_value(client, FSCPOS_REG_VOLT_12);
+		data->volt[1] = fscpos_read_value(client, FSCPOS_REG_VOLT_5);
+		data->volt[2] = fscpos_read_value(client, FSCPOS_REG_VOLT_BATT);
+
+		data->wdog_preset = fscpos_read_value(client,
+							FSCPOS_REG_WDOG_PRESET);
+		data->wdog_state = fscpos_read_value(client,
+							FSCPOS_REG_WDOG_STATE);
+		data->wdog_control = fscpos_read_value(client,
+						FSCPOS_REG_WDOG_CONTROL);
+
+		data->global_event = fscpos_read_value(client,
+						FSCPOS_REG_EVENT_STATE);
+
+		data->last_updated = jiffies;
+		data->valid = 1;
+	}
+	up(&data->update_lock);
+	return data;
+}
+
+static int __init sm_fscpos_init(void)
+{
+	return i2c_add_driver(&fscpos_driver);
+}
+
+static void __exit sm_fscpos_exit(void)
+{
+	i2c_del_driver(&fscpos_driver);
+}
+
+MODULE_AUTHOR("Stefan Ott <stefan@desire.ch> based on work from Hermann Jung "
+				"<hej@odn.de>, Frodo Looijaard <frodol@dds.nl>"
+				" and Philip Edelbrock <phil@netroedge.com>");
+MODULE_DESCRIPTION("fujitsu siemens poseidon chip driver");
+MODULE_LICENSE("GPL");
+
+module_init(sm_fscpos_init);
+module_exit(sm_fscpos_exit);