drivers/hwmon/sis5595.c

/*
    sis5595.c - Part of lm_sensors, Linux kernel modules
		for hardware monitoring

    Copyright (C) 1998 - 2001 Frodo Looijaard <frodol@dds.nl>,
			Kyösti Mälkki <kmalkki@cc.hut.fi>, and
			Mark D. Studebaker <mdsxyz123@yahoo.com>
    Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
    the help of Jean Delvare <khali@linux-fr.org>

    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.
*/

/*
   SiS southbridge has a LM78-like chip integrated on the same IC.
   This driver is a customized copy of lm78.c
   
   Supports following revisions:
	Version		PCI ID		PCI Revision
	1		1039/0008	AF or less
	2		1039/0008	B0 or greater

   Note: these chips contain a 0008 device which is incompatible with the
	 5595. We recognize these by the presence of the listed
	 "blacklist" PCI ID and refuse to load.

   NOT SUPPORTED	PCI ID		BLACKLIST PCI ID	
	 540		0008		0540
	 550		0008		0550
	5513		0008		5511
	5581		0008		5597
	5582		0008		5597
	5597		0008		5597
	5598		0008		5597/5598
	 630		0008		0630
	 645		0008		0645
	 730		0008		0730
	 735		0008		0735
*/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/i2c.h>
#include <linux/i2c-isa.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <asm/io.h>


/* If force_addr is set to anything different from 0, we forcibly enable
   the device at the given address. */
static u16 force_addr;
module_param(force_addr, ushort, 0);
MODULE_PARM_DESC(force_addr,
		 "Initialize the base address of the sensors");

/* Device address
   Note that we can't determine the ISA address until we have initialized
   our module */
static unsigned short address;

/* Many SIS5595 constants specified below */

/* Length of ISA address segment */
#define SIS5595_EXTENT 8
/* PCI Config Registers */
#define SIS5595_REVISION_REG 0x08
#define SIS5595_BASE_REG 0x68
#define SIS5595_PIN_REG 0x7A
#define SIS5595_ENABLE_REG 0x7B

/* Where are the ISA address/data registers relative to the base address */
#define SIS5595_ADDR_REG_OFFSET 5
#define SIS5595_DATA_REG_OFFSET 6

/* The SIS5595 registers */
#define SIS5595_REG_IN_MAX(nr) (0x2b + (nr) * 2)
#define SIS5595_REG_IN_MIN(nr) (0x2c + (nr) * 2)
#define SIS5595_REG_IN(nr) (0x20 + (nr))

#define SIS5595_REG_FAN_MIN(nr) (0x3b + (nr))
#define SIS5595_REG_FAN(nr) (0x28 + (nr))

/* On the first version of the chip, the temp registers are separate.
   On the second version,
   TEMP pin is shared with IN4, configured in PCI register 0x7A.
   The registers are the same as well.
   OVER and HYST are really MAX and MIN. */

#define REV2MIN	0xb0
#define SIS5595_REG_TEMP 	(( data->revision) >= REV2MIN) ? \
					SIS5595_REG_IN(4) : 0x27
#define SIS5595_REG_TEMP_OVER	(( data->revision) >= REV2MIN) ? \
					SIS5595_REG_IN_MAX(4) : 0x39
#define SIS5595_REG_TEMP_HYST	(( data->revision) >= REV2MIN) ? \
					SIS5595_REG_IN_MIN(4) : 0x3a

#define SIS5595_REG_CONFIG 0x40
#define SIS5595_REG_ALARM1 0x41
#define SIS5595_REG_ALARM2 0x42
#define SIS5595_REG_FANDIV 0x47

/* Conversions. Limit checking is only done on the TO_REG
   variants. */

/* IN: mV, (0V to 4.08V)
   REG: 16mV/bit */
static inline u8 IN_TO_REG(unsigned long val)
{
	unsigned long nval = SENSORS_LIMIT(val, 0, 4080);
	return (nval + 8) / 16;
}
#define IN_FROM_REG(val) ((val) *  16)

static inline u8 FAN_TO_REG(long rpm, int div)
{
	if (rpm <= 0)
		return 255;
	return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}

static inline int FAN_FROM_REG(u8 val, int div)
{
	return val==0 ? -1 : val==255 ? 0 : 1350000/(val*div);
}

/* TEMP: mC (-54.12C to +157.53C)
   REG: 0.83C/bit + 52.12, two's complement  */
static inline int TEMP_FROM_REG(s8 val)
{
	return val * 830 + 52120;
}
static inline s8 TEMP_TO_REG(int val)
{
	int nval = SENSORS_LIMIT(val, -54120, 157530) ;
	return nval<0 ? (nval-5212-415)/830 : (nval-5212+415)/830;
}

/* FAN DIV: 1, 2, 4, or 8 (defaults to 2)
   REG: 0, 1, 2, or 3 (respectively) (defaults to 1) */
static inline u8 DIV_TO_REG(int val)
{
	return val==8 ? 3 : val==4 ? 2 : val==1 ? 0 : 1;
}
#define DIV_FROM_REG(val) (1 << (val))

/* For each registered chip, we need to keep some data in memory.
   The structure is dynamically allocated. */
struct sis5595_data {
	struct i2c_client client;
	struct class_device *class_dev;
	struct mutex lock;

	struct mutex update_lock;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */
	char maxins;		/* == 3 if temp enabled, otherwise == 4 */
	u8 revision;		/* Reg. value */

	u8 in[5];		/* Register value */
	u8 in_max[5];		/* Register value */
	u8 in_min[5];		/* Register value */
	u8 fan[2];		/* Register value */
	u8 fan_min[2];		/* Register value */
	s8 temp;		/* Register value */
	s8 temp_over;		/* Register value */
	s8 temp_hyst;		/* Register value */
	u8 fan_div[2];		/* Register encoding, shifted right */
	u16 alarms;		/* Register encoding, combined */
};

static struct pci_dev *s_bridge;	/* pointer to the (only) sis5595 */

static int sis5595_detect(struct i2c_adapter *adapter);
static int sis5595_detach_client(struct i2c_client *client);

static int sis5595_read_value(struct i2c_client *client, u8 reg);
static int sis5595_write_value(struct i2c_client *client, u8 reg, u8 value);
static struct sis5595_data *sis5595_update_device(struct device *dev);
static void sis5595_init_client(struct i2c_client *client);

static struct i2c_driver sis5595_driver = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= "sis5595",
	},
	.attach_adapter	= sis5595_detect,
	.detach_client	= sis5595_detach_client,
};

/* 4 Voltages */
static ssize_t show_in(struct device *dev, char *buf, int nr)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", IN_FROM_REG(data->in[nr]));
}

static ssize_t show_in_min(struct device *dev, char *buf, int nr)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_min[nr]));
}

static ssize_t show_in_max(struct device *dev, char *buf, int nr)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_max[nr]));
}

static ssize_t set_in_min(struct device *dev, const char *buf,
	       size_t count, int nr)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct sis5595_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->in_min[nr] = IN_TO_REG(val);
	sis5595_write_value(client, SIS5595_REG_IN_MIN(nr), data->in_min[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t set_in_max(struct device *dev, const char *buf,
	       size_t count, int nr)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct sis5595_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->in_max[nr] = IN_TO_REG(val);
	sis5595_write_value(client, SIS5595_REG_IN_MAX(nr), data->in_max[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}

#define show_in_offset(offset)					\
static ssize_t							\
	show_in##offset (struct device *dev, struct device_attribute *attr, char *buf)		\
{								\
	return show_in(dev, buf, offset);			\
}								\
static DEVICE_ATTR(in##offset##_input, S_IRUGO, 		\
		show_in##offset, NULL);				\
static ssize_t							\
	show_in##offset##_min (struct device *dev, struct device_attribute *attr, char *buf)	\
{								\
	return show_in_min(dev, buf, offset);			\
}								\
static ssize_t							\
	show_in##offset##_max (struct device *dev, struct device_attribute *attr, char *buf)	\
{								\
	return show_in_max(dev, buf, offset);			\
}								\
static ssize_t set_in##offset##_min (struct device *dev, struct device_attribute *attr,	\
		const char *buf, size_t count)			\
{								\
	return set_in_min(dev, buf, count, offset);		\
}								\
static ssize_t set_in##offset##_max (struct device *dev, struct device_attribute *attr,	\
		const char *buf, size_t count)			\
{								\
	return set_in_max(dev, buf, count, offset);		\
}								\
static DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR,		\
		show_in##offset##_min, set_in##offset##_min);	\
static DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR,		\
		show_in##offset##_max, set_in##offset##_max);

show_in_offset(0);
show_in_offset(1);
show_in_offset(2);
show_in_offset(3);
show_in_offset(4);

/* Temperature */
static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp));
}

static ssize_t show_temp_over(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over));
}

static ssize_t set_temp_over(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct sis5595_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->temp_over = TEMP_TO_REG(val);
	sis5595_write_value(client, SIS5595_REG_TEMP_OVER, data->temp_over);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_temp_hyst(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_hyst));
}

static ssize_t set_temp_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct sis5595_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->temp_hyst = TEMP_TO_REG(val);
	sis5595_write_value(client, SIS5595_REG_TEMP_HYST, data->temp_hyst);
	mutex_unlock(&data->update_lock);
	return count;
}

static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
static DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
		show_temp_over, set_temp_over);
static DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR,
		show_temp_hyst, set_temp_hyst);

/* 2 Fans */
static ssize_t show_fan(struct device *dev, char *buf, int nr)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
		DIV_FROM_REG(data->fan_div[nr])) );
}

static ssize_t show_fan_min(struct device *dev, char *buf, int nr)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf,"%d\n", FAN_FROM_REG(data->fan_min[nr],
		DIV_FROM_REG(data->fan_div[nr])) );
}

static ssize_t set_fan_min(struct device *dev, const char *buf,
		size_t count, int nr)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct sis5595_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
	sis5595_write_value(client, SIS5595_REG_FAN_MIN(nr), data->fan_min[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_fan_div(struct device *dev, char *buf, int nr)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]) );
}

/* Note: we save and restore the fan minimum here, because its value is
   determined in part by the fan divisor.  This follows the principle of
   least surprise; the user doesn't expect the fan minimum to change just
   because the divisor changed. */
static ssize_t set_fan_div(struct device *dev, const char *buf,
	size_t count, int nr)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct sis5595_data *data = i2c_get_clientdata(client);
	unsigned long min;
	unsigned long val = simple_strtoul(buf, NULL, 10);
	int reg;

	mutex_lock(&data->update_lock);
	min = FAN_FROM_REG(data->fan_min[nr],
			DIV_FROM_REG(data->fan_div[nr]));
	reg = sis5595_read_value(client, SIS5595_REG_FANDIV);

	switch (val) {
	case 1: data->fan_div[nr] = 0; break;
	case 2: data->fan_div[nr] = 1; break;
	case 4: data->fan_div[nr] = 2; break;
	case 8: data->fan_div[nr] = 3; break;
	default:
		dev_err(&client->dev, "fan_div value %ld not "
			"supported. Choose one of 1, 2, 4 or 8!\n", val);
		mutex_unlock(&data->update_lock);
		return -EINVAL;
	}
	
	switch (nr) {
	case 0:
		reg = (reg & 0xcf) | (data->fan_div[nr] << 4);
		break;
	case 1:
		reg = (reg & 0x3f) | (data->fan_div[nr] << 6);
		break;
	}
	sis5595_write_value(client, SIS5595_REG_FANDIV, reg);
	data->fan_min[nr] =
		FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
	sis5595_write_value(client, SIS5595_REG_FAN_MIN(nr), data->fan_min[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}

#define show_fan_offset(offset)						\
static ssize_t show_fan_##offset (struct device *dev, struct device_attribute *attr, char *buf)	\
{									\
	return show_fan(dev, buf, offset - 1);			\
}									\
static ssize_t show_fan_##offset##_min (struct device *dev, struct device_attribute *attr, char *buf)	\
{									\
	return show_fan_min(dev, buf, offset - 1);			\
}									\
static ssize_t show_fan_##offset##_div (struct device *dev, struct device_attribute *attr, char *buf)	\
{									\
	return show_fan_div(dev, buf, offset - 1);			\
}									\
static ssize_t set_fan_##offset##_min (struct device *dev, struct device_attribute *attr,		\
		const char *buf, size_t count)				\
{									\
	return set_fan_min(dev, buf, count, offset - 1);		\
}									\
static DEVICE_ATTR(fan##offset##_input, S_IRUGO, show_fan_##offset, NULL);\
static DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,		\
		show_fan_##offset##_min, set_fan_##offset##_min);

show_fan_offset(1);
show_fan_offset(2);

static ssize_t set_fan_1_div(struct device *dev, struct device_attribute *attr, const char *buf,
		size_t count)
{
	return set_fan_div(dev, buf, count, 0) ;
}

static ssize_t set_fan_2_div(struct device *dev, struct device_attribute *attr, const char *buf,
		size_t count)
{
	return set_fan_div(dev, buf, count, 1) ;
}
static DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR,
		show_fan_1_div, set_fan_1_div);
static DEVICE_ATTR(fan2_div, S_IRUGO | S_IWUSR,
		show_fan_2_div, set_fan_2_div);

/* Alarms */
static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct sis5595_data *data = sis5595_update_device(dev);
	return sprintf(buf, "%d\n", data->alarms);
}
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

static struct attribute *sis5595_attributes[] = {
	&dev_attr_in0_input.attr,
	&dev_attr_in0_min.attr,
	&dev_attr_in0_max.attr,
	&dev_attr_in1_input.attr,
	&dev_attr_in1_min.attr,
	&dev_attr_in1_max.attr,
	&dev_attr_in2_input.attr,
	&dev_attr_in2_min.attr,
	&dev_attr_in2_max.attr,
	&dev_attr_in3_input.attr,
	&dev_attr_in3_min.attr,
	&dev_attr_in3_max.attr,

	&dev_attr_fan1_input.attr,
	&dev_attr_fan1_min.attr,
	&dev_attr_fan1_div.attr,
	&dev_attr_fan2_input.attr,
	&dev_attr_fan2_min.attr,
	&dev_attr_fan2_div.attr,

	&dev_attr_alarms.attr,
	NULL
};

static const struct attribute_group sis5595_group = {
	.attrs = sis5595_attributes,
};

static struct attribute *sis5595_attributes_opt[] = {
	&dev_attr_in4_input.attr,
	&dev_attr_in4_min.attr,
	&dev_attr_in4_max.attr,

	&dev_attr_temp1_input.attr,
	&dev_attr_temp1_max.attr,
	&dev_attr_temp1_max_hyst.attr,
	NULL
};

static const struct attribute_group sis5595_group_opt = {
	.attrs = sis5595_attributes_opt,
};
 
/* This is called when the module is loaded */
static int sis5595_detect(struct i2c_adapter *adapter)
{
	int err = 0;
	int i;
	struct i2c_client *new_client;
	struct sis5595_data *data;
	char val;
	u16 a;

	if (force_addr)
		address = force_addr & ~(SIS5595_EXTENT - 1);
	/* Reserve the ISA region */
	if (!request_region(address, SIS5595_EXTENT,
			    sis5595_driver.driver.name)) {
		err = -EBUSY;
		goto exit;
	}
	if (force_addr) {
		dev_warn(&adapter->dev, "forcing ISA address 0x%04X\n", address);
		if (PCIBIOS_SUCCESSFUL !=
		    pci_write_config_word(s_bridge, SIS5595_BASE_REG, address))
			goto exit_release;
		if (PCIBIOS_SUCCESSFUL !=
		    pci_read_config_word(s_bridge, SIS5595_BASE_REG, &a))
			goto exit_release;
		if ((a & ~(SIS5595_EXTENT - 1)) != address)
			/* doesn't work for some chips? */
			goto exit_release;
	}

	if (PCIBIOS_SUCCESSFUL !=
	    pci_read_config_byte(s_bridge, SIS5595_ENABLE_REG, &val)) {
		goto exit_release;
	}
	if ((val & 0x80) == 0) {
		if (PCIBIOS_SUCCESSFUL !=
		    pci_write_config_byte(s_bridge, SIS5595_ENABLE_REG,
					  val | 0x80))
			goto exit_release;
		if (PCIBIOS_SUCCESSFUL !=
		    pci_read_config_byte(s_bridge, SIS5595_ENABLE_REG, &val))
			goto exit_release;
		if ((val & 0x80) == 0) 
			/* doesn't work for some chips! */
			goto exit_release;
	}

	if (!(data = kzalloc(sizeof(struct sis5595_data), GFP_KERNEL))) {
		err = -ENOMEM;
		goto exit_release;
	}

	new_client = &data->client;
	new_client->addr = address;
	mutex_init(&data->lock);
	i2c_set_clientdata(new_client, data);
	new_client->adapter = adapter;
	new_client->driver = &sis5595_driver;
	new_client->flags = 0;

	/* Check revision and pin registers to determine whether 4 or 5 voltages */
	pci_read_config_byte(s_bridge, SIS5595_REVISION_REG, &(data->revision));
	/* 4 voltages, 1 temp */
	data->maxins = 3;
	if (data->revision >= REV2MIN) {
		pci_read_config_byte(s_bridge, SIS5595_PIN_REG, &val);
		if (!(val & 0x80))
			/* 5 voltages, no temps */
			data->maxins = 4;
	}
	
	/* Fill in the remaining client fields and put it into the global list */
	strlcpy(new_client->name, "sis5595", I2C_NAME_SIZE);

	data->valid = 0;
	mutex_init(&data->update_lock);

	/* Tell the I2C layer a new client has arrived */
	if ((err = i2c_attach_client(new_client)))
		goto exit_free;
	
	/* Initialize the SIS5595 chip */
	sis5595_init_client(new_client);

	/* A few vars need to be filled upon startup */
	for (i = 0; i < 2; i++) {
		data->fan_min[i] = sis5595_read_value(new_client,
					SIS5595_REG_FAN_MIN(i));
	}

	/* Register sysfs hooks */
	if ((err = sysfs_create_group(&new_client->dev.kobj, &sis5595_group)))
		goto exit_detach;
	if (data->maxins == 4) {
		if ((err = device_create_file(&new_client->dev,
					      &dev_attr_in4_input))
		 || (err = device_create_file(&new_client->dev,
					      &dev_attr_in4_min))
		 || (err = device_create_file(&new_client->dev,
					      &dev_attr_in4_max)))
			goto exit_remove_files;
	} else {
		if ((err = device_create_file(&new_client->dev,
					      &dev_attr_temp1_input))
		 || (err = device_create_file(&new_client->dev,
					      &dev_attr_temp1_max))
		 || (err = device_create_file(&new_client->dev,
					      &dev_attr_temp1_max_hyst)))
			goto exit_remove_files;
	}

	data->class_dev = hwmon_device_register(&new_client->dev);
	if (IS_ERR(data->class_dev)) {
		err = PTR_ERR(data->class_dev);
		goto exit_remove_files;
	}

	return 0;

exit_remove_files:
	sysfs_remove_group(&new_client->dev.kobj, &sis5595_group);
	sysfs_remove_group(&new_client->dev.kobj, &sis5595_group_opt);
exit_detach:
	i2c_detach_client(new_client);
exit_free:
	kfree(data);
exit_release:
	release_region(address, SIS5595_EXTENT);
exit:
	return err;
}

static int sis5595_detach_client(struct i2c_client *client)
{
	struct sis5595_data *data = i2c_get_clientdata(client);
	int err;

	hwmon_device_unregister(data->class_dev);
	sysfs_remove_group(&client->dev.kobj, &sis5595_group);
	sysfs_remove_group(&client->dev.kobj, &sis5595_group_opt);

	if ((err = i2c_detach_client(client)))
		return err;

	release_region(client->addr, SIS5595_EXTENT);

	kfree(data);

	return 0;
}


/* ISA access must be locked explicitly. */
static int sis5595_read_value(struct i2c_client *client, u8 reg)
{
	int res;

	struct sis5595_data *data = i2c_get_clientdata(client);
	mutex_lock(&data->lock);
	outb_p(reg, client->addr + SIS5595_ADDR_REG_OFFSET);
	res = inb_p(client->addr + SIS5595_DATA_REG_OFFSET);
	mutex_unlock(&data->lock);
	return res;
}

static int sis5595_write_value(struct i2c_client *client, u8 reg, u8 value)
{
	struct sis5595_data *data = i2c_get_clientdata(client);
	mutex_lock(&data->lock);
	outb_p(reg, client->addr + SIS5595_ADDR_REG_OFFSET);
	outb_p(value, client->addr + SIS5595_DATA_REG_OFFSET);
	mutex_unlock(&data->lock);
	return 0;
}

/* Called when we have found a new SIS5595. */
static void sis5595_init_client(struct i2c_client *client)
{
	u8 config = sis5595_read_value(client, SIS5595_REG_CONFIG);
	if (!(config & 0x01))
		sis5595_write_value(client, SIS5595_REG_CONFIG,
				(config & 0xf7) | 0x01);
}

static struct sis5595_data *sis5595_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct sis5595_data *data = i2c_get_clientdata(client);
	int i;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	    || !data->valid) {

		for (i = 0; i <= data->maxins; i++) {
			data->in[i] =
			    sis5595_read_value(client, SIS5595_REG_IN(i));
			data->in_min[i] =
			    sis5595_read_value(client,
					       SIS5595_REG_IN_MIN(i));
			data->in_max[i] =
			    sis5595_read_value(client,
					       SIS5595_REG_IN_MAX(i));
		}
		for (i = 0; i < 2; i++) {
			data->fan[i] =
			    sis5595_read_value(client, SIS5595_REG_FAN(i));
			data->fan_min[i] =
			    sis5595_read_value(client,
					       SIS5595_REG_FAN_MIN(i));
		}
		if (data->maxins == 3) {
			data->temp =
			    sis5595_read_value(client, SIS5595_REG_TEMP);
			data->temp_over =
			    sis5595_read_value(client, SIS5595_REG_TEMP_OVER);
			data->temp_hyst =
			    sis5595_read_value(client, SIS5595_REG_TEMP_HYST);
		}
		i = sis5595_read_value(client, SIS5595_REG_FANDIV);
		data->fan_div[0] = (i >> 4) & 0x03;
		data->fan_div[1] = i >> 6;
		data->alarms =
		    sis5595_read_value(client, SIS5595_REG_ALARM1) |
		    (sis5595_read_value(client, SIS5595_REG_ALARM2) << 8);
		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

static struct pci_device_id sis5595_pci_ids[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
	{ 0, }
};

MODULE_DEVICE_TABLE(pci, sis5595_pci_ids);

static int blacklist[] __devinitdata = {
	PCI_DEVICE_ID_SI_540,
	PCI_DEVICE_ID_SI_550,
	PCI_DEVICE_ID_SI_630,
	PCI_DEVICE_ID_SI_645,
	PCI_DEVICE_ID_SI_730,
	PCI_DEVICE_ID_SI_735,
	PCI_DEVICE_ID_SI_5511, /* 5513 chip has the 0008 device but
				  that ID shows up in other chips so we
				  use the 5511 ID for recognition */
	PCI_DEVICE_ID_SI_5597,
	PCI_DEVICE_ID_SI_5598,
	0 };

static int __devinit sis5595_pci_probe(struct pci_dev *dev,
				       const struct pci_device_id *id)
{
	u16 val;
	int *i;

	for (i = blacklist; *i != 0; i++) {
		struct pci_dev *dev;
		dev = pci_get_device(PCI_VENDOR_ID_SI, *i, NULL);
		if (dev) {
			dev_err(&dev->dev, "Looked for SIS5595 but found unsupported device %.4x\n", *i);
			pci_dev_put(dev);
			return -ENODEV;
		}
	}
	
	if (PCIBIOS_SUCCESSFUL !=
	    pci_read_config_word(dev, SIS5595_BASE_REG, &val))
		return -ENODEV;
	
	address = val & ~(SIS5595_EXTENT - 1);
	if (address == 0 && force_addr == 0) {
		dev_err(&dev->dev, "Base address not set - upgrade BIOS or use force_addr=0xaddr\n");
		return -ENODEV;
	}

	s_bridge = pci_dev_get(dev);
	if (i2c_isa_add_driver(&sis5595_driver)) {
		pci_dev_put(s_bridge);
		s_bridge = NULL;
	}

	/* Always return failure here.  This is to allow other drivers to bind
	 * to this pci device.  We don't really want to have control over the
	 * pci device, we only wanted to read as few register values from it.
	 */
	return -ENODEV;
}

static struct pci_driver sis5595_pci_driver = {
	.name            = "sis5595",
	.id_table        = sis5595_pci_ids,
	.probe           = sis5595_pci_probe,
};

static int __init sm_sis5595_init(void)
{
	return pci_register_driver(&sis5595_pci_driver);
}

static void __exit sm_sis5595_exit(void)
{
	pci_unregister_driver(&sis5595_pci_driver);
	if (s_bridge != NULL) {
		i2c_isa_del_driver(&sis5595_driver);
		pci_dev_put(s_bridge);
		s_bridge = NULL;
	}
}

MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
MODULE_DESCRIPTION("SiS 5595 Sensor device");
MODULE_LICENSE("GPL");

module_init(sm_sis5595_init);
module_exit(sm_sis5595_exit);