drivers/misc/ics932s401.c - nest-learning-thermostat/5.6.1/linux - Git at Google

 /*
  * A driver for the Integrated Circuits ICS932S401
  * Copyright (C) 2008 IBM
  *
  * Author: Darrick J. Wong <djwong@us.ibm.com>
  *
  * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #include <linux/module.h>
 #include <linux/jiffies.h>
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/delay.h>
 #include <linux/log2.h>
 #include <linux/slab.h>

 /* Addresses to scan */
 static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };

 /* ICS932S401 registers */
 #define ICS932S401_REG_CFG2			0x01
 #define 	ICS932S401_CFG1_SPREAD		0x01
 #define ICS932S401_REG_CFG7			0x06
 #define		ICS932S401_FS_MASK		0x07
 #define	ICS932S401_REG_VENDOR_REV		0x07
 #define		ICS932S401_VENDOR		1
 #define		ICS932S401_VENDOR_MASK		0x0F
 #define		ICS932S401_REV			4
 #define		ICS932S401_REV_SHIFT		4
 #define ICS932S401_REG_DEVICE			0x09
 #define		ICS932S401_DEVICE		11
 #define	ICS932S401_REG_CTRL			0x0A
 #define		ICS932S401_MN_ENABLED		0x80
 #define		ICS932S401_CPU_ALT		0x04
 #define		ICS932S401_SRC_ALT		0x08
 #define ICS932S401_REG_CPU_M_CTRL		0x0B
 #define		ICS932S401_M_MASK		0x3F
 #define	ICS932S401_REG_CPU_N_CTRL		0x0C
 #define	ICS932S401_REG_CPU_SPREAD1		0x0D
 #define ICS932S401_REG_CPU_SPREAD2		0x0E
 #define		ICS932S401_SPREAD_MASK		0x7FFF
 #define ICS932S401_REG_SRC_M_CTRL		0x0F
 #define ICS932S401_REG_SRC_N_CTRL		0x10
 #define	ICS932S401_REG_SRC_SPREAD1		0x11
 #define ICS932S401_REG_SRC_SPREAD2		0x12
 #define ICS932S401_REG_CPU_DIVISOR		0x13
 #define 	ICS932S401_CPU_DIVISOR_SHIFT	4
 #define ICS932S401_REG_PCISRC_DIVISOR		0x14
 #define		ICS932S401_SRC_DIVISOR_MASK	0x0F
 #define		ICS932S401_PCI_DIVISOR_SHIFT	4

 /* Base clock is 14.318MHz */
 #define BASE_CLOCK				14318

 #define NUM_REGS				21
 #define NUM_MIRRORED_REGS			15

 static int regs_to_copy[NUM_MIRRORED_REGS] = {
 	ICS932S401_REG_CFG2,
 	ICS932S401_REG_CFG7,
 	ICS932S401_REG_VENDOR_REV,
 	ICS932S401_REG_DEVICE,
 	ICS932S401_REG_CTRL,
 	ICS932S401_REG_CPU_M_CTRL,
 	ICS932S401_REG_CPU_N_CTRL,
 	ICS932S401_REG_CPU_SPREAD1,
 	ICS932S401_REG_CPU_SPREAD2,
 	ICS932S401_REG_SRC_M_CTRL,
 	ICS932S401_REG_SRC_N_CTRL,
 	ICS932S401_REG_SRC_SPREAD1,
 	ICS932S401_REG_SRC_SPREAD2,
 	ICS932S401_REG_CPU_DIVISOR,
 	ICS932S401_REG_PCISRC_DIVISOR,
 };

 /* How often do we reread sensors values? (In jiffies) */
 #define SENSOR_REFRESH_INTERVAL	(2 * HZ)

 /* How often do we reread sensor limit values? (In jiffies) */
 #define LIMIT_REFRESH_INTERVAL	(60 * HZ)

 struct ics932s401_data {
 	struct attribute_group	attrs;
 	struct mutex		lock;
 	char			sensors_valid;
 	unsigned long		sensors_last_updated;	/* In jiffies */

 	u8			regs[NUM_REGS];
 };

 static int ics932s401_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id);
 static int ics932s401_detect(struct i2c_client *client,
 			  struct i2c_board_info *info);
 static int ics932s401_remove(struct i2c_client *client);

 static const struct i2c_device_id ics932s401_id[] = {
 	{ "ics932s401", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ics932s401_id);

 static struct i2c_driver ics932s401_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "ics932s401",
 	},
 	.probe		= ics932s401_probe,
 	.remove		= ics932s401_remove,
 	.id_table	= ics932s401_id,
 	.detect		= ics932s401_detect,
 	.address_list	= normal_i2c,
 };

 static struct ics932s401_data *ics932s401_update_device(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct ics932s401_data *data = i2c_get_clientdata(client);
 	unsigned long local_jiffies = jiffies;
 	int i, temp;

 	mutex_lock(&data->lock);
 	if (time_before(local_jiffies, data->sensors_last_updated +
 		SENSOR_REFRESH_INTERVAL)
 		&& data->sensors_valid)
 		goto out;

 	/*
 	 * Each register must be read as a word and then right shifted 8 bits.
 	 * Not really sure why this is; setting the "byte count programming"
 	 * register to 1 does not fix this problem.
 	 */
 	for (i = 0; i < NUM_MIRRORED_REGS; i++) {
 		temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
 		data->regs[regs_to_copy[i]] = temp >> 8;
 	}

 	data->sensors_last_updated = local_jiffies;
 	data->sensors_valid = 1;

 out:
 	mutex_unlock(&data->lock);
 	return data;
 }

 static ssize_t show_spread_enabled(struct device *dev,
 				   struct device_attribute *devattr,
 				   char *buf)
 {
 	struct ics932s401_data *data = ics932s401_update_device(dev);

 	if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
 		return sprintf(buf, "1\n");

 	return sprintf(buf, "0\n");
 }

 /* bit to cpu khz map */
 static const int fs_speeds[] = {
 	266666,
 	133333,
 	200000,
 	166666,
 	333333,
 	100000,
 	400000,
 	0,
 };

 /* clock divisor map */
 static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
 			       24, 40, 120};

 /* Calculate CPU frequency from the M/N registers. */
 static int calculate_cpu_freq(struct ics932s401_data *data)
 {
 	int m, n, freq;

 	m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
 	n = data->regs[ICS932S401_REG_CPU_N_CTRL];

 	/* Pull in bits 8 & 9 from the M register */
 	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
 	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;

 	freq = BASE_CLOCK * (n + 8) / (m + 2);
 	freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
 			 ICS932S401_CPU_DIVISOR_SHIFT];

 	return freq;
 }

 static ssize_t show_cpu_clock(struct device *dev,
 			      struct device_attribute *devattr,
 			      char *buf)
 {
 	struct ics932s401_data *data = ics932s401_update_device(dev);

 	return sprintf(buf, "%d\n", calculate_cpu_freq(data));
 }

 static ssize_t show_cpu_clock_sel(struct device *dev,
 				  struct device_attribute *devattr,
 				  char *buf)
 {
 	struct ics932s401_data *data = ics932s401_update_device(dev);
 	int freq;

 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
 		freq = calculate_cpu_freq(data);
 	else {
 		/* Freq is neatly wrapped up for us */
 		int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
 		freq = fs_speeds[fid];
 		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
 			switch (freq) {
 			case 166666:
 				freq = 160000;
 				break;
 			case 333333:
 				freq = 320000;
 				break;
 			}
 		}
 	}

 	return sprintf(buf, "%d\n", freq);
 }

 /* Calculate SRC frequency from the M/N registers. */
 static int calculate_src_freq(struct ics932s401_data *data)
 {
 	int m, n, freq;

 	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
 	n = data->regs[ICS932S401_REG_SRC_N_CTRL];

 	/* Pull in bits 8 & 9 from the M register */
 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;

 	freq = BASE_CLOCK * (n + 8) / (m + 2);
 	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
 			 ICS932S401_SRC_DIVISOR_MASK];

 	return freq;
 }

 static ssize_t show_src_clock(struct device *dev,
 			      struct device_attribute *devattr,
 			      char *buf)
 {
 	struct ics932s401_data *data = ics932s401_update_device(dev);

 	return sprintf(buf, "%d\n", calculate_src_freq(data));
 }

 static ssize_t show_src_clock_sel(struct device *dev,
 				  struct device_attribute *devattr,
 				  char *buf)
 {
 	struct ics932s401_data *data = ics932s401_update_device(dev);
 	int freq;

 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
 		freq = calculate_src_freq(data);
 	else
 		/* Freq is neatly wrapped up for us */
 		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
 		    data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
 			freq = 96000;
 		else
 			freq = 100000;

 	return sprintf(buf, "%d\n", freq);
 }

 /* Calculate PCI frequency from the SRC M/N registers. */
 static int calculate_pci_freq(struct ics932s401_data *data)
 {
 	int m, n, freq;

 	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
 	n = data->regs[ICS932S401_REG_SRC_N_CTRL];

 	/* Pull in bits 8 & 9 from the M register */
 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;

 	freq = BASE_CLOCK * (n + 8) / (m + 2);
 	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
 			 ICS932S401_PCI_DIVISOR_SHIFT];

 	return freq;
 }

 static ssize_t show_pci_clock(struct device *dev,
 			      struct device_attribute *devattr,
 			      char *buf)
 {
 	struct ics932s401_data *data = ics932s401_update_device(dev);

 	return sprintf(buf, "%d\n", calculate_pci_freq(data));
 }

 static ssize_t show_pci_clock_sel(struct device *dev,
 				  struct device_attribute *devattr,
 				  char *buf)
 {
 	struct ics932s401_data *data = ics932s401_update_device(dev);
 	int freq;

 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
 		freq = calculate_pci_freq(data);
 	else
 		freq = 33333;

 	return sprintf(buf, "%d\n", freq);
 }

 static ssize_t show_value(struct device *dev,
 			  struct device_attribute *devattr,
 			  char *buf);

 static ssize_t show_spread(struct device *dev,
 			   struct device_attribute *devattr,
 			   char *buf);

 static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
 static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
 static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
 static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
 static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
 static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
 static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
 static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
 static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
 static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
 static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);

 static struct attribute *ics932s401_attr[] =
 {
 	&dev_attr_spread_enabled.attr,
 	&dev_attr_cpu_clock_selection.attr,
 	&dev_attr_cpu_clock.attr,
 	&dev_attr_src_clock_selection.attr,
 	&dev_attr_src_clock.attr,
 	&dev_attr_pci_clock_selection.attr,
 	&dev_attr_pci_clock.attr,
 	&dev_attr_usb_clock.attr,
 	&dev_attr_ref_clock.attr,
 	&dev_attr_cpu_spread.attr,
 	&dev_attr_src_spread.attr,
 	NULL
 };

 static ssize_t show_value(struct device *dev,
 			  struct device_attribute *devattr,
 			  char *buf)
 {
 	int x;

 	if (devattr == &dev_attr_usb_clock)
 		x = 48000;
 	else if (devattr == &dev_attr_ref_clock)
 		x = BASE_CLOCK;
 	else
 		BUG();

 	return sprintf(buf, "%d\n", x);
 }

 static ssize_t show_spread(struct device *dev,
 			   struct device_attribute *devattr,
 			   char *buf)
 {
 	struct ics932s401_data *data = ics932s401_update_device(dev);
 	int reg;
 	unsigned long val;

 	if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
 		return sprintf(buf, "0%%\n");

 	if (devattr == &dev_attr_src_spread)
 		reg = ICS932S401_REG_SRC_SPREAD1;
 	else if (devattr == &dev_attr_cpu_spread)
 		reg = ICS932S401_REG_CPU_SPREAD1;
 	else
 		BUG();

 	val = data->regs[reg] | (data->regs[reg + 1] << 8);
 	val &= ICS932S401_SPREAD_MASK;

 	/* Scale 0..2^14 to -0.5. */
 	val = 500000 * val / 16384;
 	return sprintf(buf, "-0.%lu%%\n", val);
 }

 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int ics932s401_detect(struct i2c_client *client,
 			  struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = client->adapter;
 	int vendor, device, revision;

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 		return -ENODEV;

 	vendor = i2c_smbus_read_word_data(client, ICS932S401_REG_VENDOR_REV);
 	vendor >>= 8;
 	revision = vendor >> ICS932S401_REV_SHIFT;
 	vendor &= ICS932S401_VENDOR_MASK;
 	if (vendor != ICS932S401_VENDOR)
 		return -ENODEV;

 	device = i2c_smbus_read_word_data(client, ICS932S401_REG_DEVICE);
 	device >>= 8;
 	if (device != ICS932S401_DEVICE)
 		return -ENODEV;

 	if (revision != ICS932S401_REV)
 		dev_info(&adapter->dev, "Unknown revision %d\n", revision);

 	strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);

 	return 0;
 }

 static int ics932s401_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct ics932s401_data *data;
 	int err;

 	data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
 	if (!data) {
 		err = -ENOMEM;
 		goto exit;
 	}

 	i2c_set_clientdata(client, data);
 	mutex_init(&data->lock);

 	dev_info(&client->dev, "%s chip found\n", client->name);

 	/* Register sysfs hooks */
 	data->attrs.attrs = ics932s401_attr;
 	err = sysfs_create_group(&client->dev.kobj, &data->attrs);
 	if (err)
 		goto exit_free;

 	return 0;

 exit_free:
 	kfree(data);
 exit:
 	return err;
 }

 static int ics932s401_remove(struct i2c_client *client)
 {
 	struct ics932s401_data *data = i2c_get_clientdata(client);

 	sysfs_remove_group(&client->dev.kobj, &data->attrs);
 	kfree(data);
 	return 0;
 }

 static int __init ics932s401_init(void)
 {
 	return i2c_add_driver(&ics932s401_driver);
 }

 static void __exit ics932s401_exit(void)
 {
 	i2c_del_driver(&ics932s401_driver);
 }

 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
 MODULE_DESCRIPTION("ICS932S401 driver");
 MODULE_LICENSE("GPL");

 module_init(ics932s401_init);
 module_exit(ics932s401_exit);

 /* IBM IntelliStation Z30 */
 MODULE_ALIAS("dmi:bvnIBM:*:rn9228:*");
 MODULE_ALIAS("dmi:bvnIBM:*:rn9232:*");

 /* IBM x3650/x3550 */
 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650*");
 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550*");
	/*
	* A driver for the Integrated Circuits ICS932S401
	* Copyright (C) 2008 IBM
	*
	* Author: Darrick J. Wong <djwong@us.ibm.com>
	*
	* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/module.h>
	#include <linux/jiffies.h>
	#include <linux/i2c.h>
	#include <linux/err.h>
	#include <linux/mutex.h>
	#include <linux/delay.h>
	#include <linux/log2.h>
	#include <linux/slab.h>

	/* Addresses to scan */
	static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };

	/* ICS932S401 registers */
	#define ICS932S401_REG_CFG2 0x01
	#define ICS932S401_CFG1_SPREAD 0x01
	#define ICS932S401_REG_CFG7 0x06
	#define ICS932S401_FS_MASK 0x07
	#define ICS932S401_REG_VENDOR_REV 0x07
	#define ICS932S401_VENDOR 1
	#define ICS932S401_VENDOR_MASK 0x0F
	#define ICS932S401_REV 4
	#define ICS932S401_REV_SHIFT 4
	#define ICS932S401_REG_DEVICE 0x09
	#define ICS932S401_DEVICE 11
	#define ICS932S401_REG_CTRL 0x0A
	#define ICS932S401_MN_ENABLED 0x80
	#define ICS932S401_CPU_ALT 0x04
	#define ICS932S401_SRC_ALT 0x08
	#define ICS932S401_REG_CPU_M_CTRL 0x0B
	#define ICS932S401_M_MASK 0x3F
	#define ICS932S401_REG_CPU_N_CTRL 0x0C
	#define ICS932S401_REG_CPU_SPREAD1 0x0D
	#define ICS932S401_REG_CPU_SPREAD2 0x0E
	#define ICS932S401_SPREAD_MASK 0x7FFF
	#define ICS932S401_REG_SRC_M_CTRL 0x0F
	#define ICS932S401_REG_SRC_N_CTRL 0x10
	#define ICS932S401_REG_SRC_SPREAD1 0x11
	#define ICS932S401_REG_SRC_SPREAD2 0x12
	#define ICS932S401_REG_CPU_DIVISOR 0x13
	#define ICS932S401_CPU_DIVISOR_SHIFT 4
	#define ICS932S401_REG_PCISRC_DIVISOR 0x14
	#define ICS932S401_SRC_DIVISOR_MASK 0x0F
	#define ICS932S401_PCI_DIVISOR_SHIFT 4

	/* Base clock is 14.318MHz */
	#define BASE_CLOCK 14318

	#define NUM_REGS 21
	#define NUM_MIRRORED_REGS 15

	static int regs_to_copy[NUM_MIRRORED_REGS] = {
	ICS932S401_REG_CFG2,
	ICS932S401_REG_CFG7,
	ICS932S401_REG_VENDOR_REV,
	ICS932S401_REG_DEVICE,
	ICS932S401_REG_CTRL,
	ICS932S401_REG_CPU_M_CTRL,
	ICS932S401_REG_CPU_N_CTRL,
	ICS932S401_REG_CPU_SPREAD1,
	ICS932S401_REG_CPU_SPREAD2,
	ICS932S401_REG_SRC_M_CTRL,
	ICS932S401_REG_SRC_N_CTRL,
	ICS932S401_REG_SRC_SPREAD1,
	ICS932S401_REG_SRC_SPREAD2,
	ICS932S401_REG_CPU_DIVISOR,
	ICS932S401_REG_PCISRC_DIVISOR,
	};

	/* How often do we reread sensors values? (In jiffies) */
	#define SENSOR_REFRESH_INTERVAL (2 * HZ)

	/* How often do we reread sensor limit values? (In jiffies) */
	#define LIMIT_REFRESH_INTERVAL (60 * HZ)

	struct ics932s401_data {
	struct attribute_group attrs;
	struct mutex lock;
	char sensors_valid;
	unsigned long sensors_last_updated; /* In jiffies */

	u8 regs[NUM_REGS];
	};

	static int ics932s401_probe(struct i2c_client *client,
	const struct i2c_device_id *id);
	static int ics932s401_detect(struct i2c_client *client,
	struct i2c_board_info *info);
	static int ics932s401_remove(struct i2c_client *client);

	static const struct i2c_device_id ics932s401_id[] = {
	{ "ics932s401", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, ics932s401_id);

	static struct i2c_driver ics932s401_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "ics932s401",
	},
	.probe = ics932s401_probe,
	.remove = ics932s401_remove,
	.id_table = ics932s401_id,
	.detect = ics932s401_detect,
	.address_list = normal_i2c,
	};

	static struct ics932s401_data ics932s401_update_device(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct ics932s401_data *data = i2c_get_clientdata(client);
	unsigned long local_jiffies = jiffies;
	int i, temp;

	mutex_lock(&data->lock);
	if (time_before(local_jiffies, data->sensors_last_updated +
	SENSOR_REFRESH_INTERVAL)
	&& data->sensors_valid)
	goto out;

	/*
	* Each register must be read as a word and then right shifted 8 bits.
	* Not really sure why this is; setting the "byte count programming"
	* register to 1 does not fix this problem.
	*/
	for (i = 0; i < NUM_MIRRORED_REGS; i++) {
	temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
	data->regs[regs_to_copy[i]] = temp >> 8;
	}

	data->sensors_last_updated = local_jiffies;
	data->sensors_valid = 1;

	out:
	mutex_unlock(&data->lock);
	return data;
	}

	static ssize_t show_spread_enabled(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	struct ics932s401_data *data = ics932s401_update_device(dev);

	if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
	return sprintf(buf, "1\n");

	return sprintf(buf, "0\n");
	}

	/* bit to cpu khz map */
	static const int fs_speeds[] = {
	266666,
	133333,
	200000,
	166666,
	333333,
	100000,
	400000,
	0,
	};

	/* clock divisor map */
	static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
	24, 40, 120};

	/* Calculate CPU frequency from the M/N registers. */
	static int calculate_cpu_freq(struct ics932s401_data *data)
	{
	int m, n, freq;

	m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
	n = data->regs[ICS932S401_REG_CPU_N_CTRL];

	/* Pull in bits 8 & 9 from the M register */
	n \|= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
	n \|= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;

	freq = BASE_CLOCK * (n + 8) / (m + 2);
	freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
	ICS932S401_CPU_DIVISOR_SHIFT];

	return freq;
	}

	static ssize_t show_cpu_clock(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	struct ics932s401_data *data = ics932s401_update_device(dev);

	return sprintf(buf, "%d\n", calculate_cpu_freq(data));
	}

	static ssize_t show_cpu_clock_sel(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	struct ics932s401_data *data = ics932s401_update_device(dev);
	int freq;

	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
	freq = calculate_cpu_freq(data);
	else {
	/* Freq is neatly wrapped up for us */
	int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
	freq = fs_speeds[fid];
	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
	switch (freq) {
	case 166666:
	freq = 160000;
	break;
	case 333333:
	freq = 320000;
	break;
	}
	}
	}

	return sprintf(buf, "%d\n", freq);
	}

	/* Calculate SRC frequency from the M/N registers. */
	static int calculate_src_freq(struct ics932s401_data *data)
	{
	int m, n, freq;

	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
	n = data->regs[ICS932S401_REG_SRC_N_CTRL];

	/* Pull in bits 8 & 9 from the M register */
	n \|= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
	n \|= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;

	freq = BASE_CLOCK * (n + 8) / (m + 2);
	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
	ICS932S401_SRC_DIVISOR_MASK];

	return freq;
	}

	static ssize_t show_src_clock(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	struct ics932s401_data *data = ics932s401_update_device(dev);

	return sprintf(buf, "%d\n", calculate_src_freq(data));
	}

	static ssize_t show_src_clock_sel(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	struct ics932s401_data *data = ics932s401_update_device(dev);
	int freq;

	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
	freq = calculate_src_freq(data);
	else
	/* Freq is neatly wrapped up for us */
	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
	data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
	freq = 96000;
	else
	freq = 100000;

	return sprintf(buf, "%d\n", freq);
	}

	/* Calculate PCI frequency from the SRC M/N registers. */
	static int calculate_pci_freq(struct ics932s401_data *data)
	{
	int m, n, freq;

	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
	n = data->regs[ICS932S401_REG_SRC_N_CTRL];

	/* Pull in bits 8 & 9 from the M register */
	n \|= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
	n \|= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;

	freq = BASE_CLOCK * (n + 8) / (m + 2);
	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
	ICS932S401_PCI_DIVISOR_SHIFT];

	return freq;
	}

	static ssize_t show_pci_clock(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	struct ics932s401_data *data = ics932s401_update_device(dev);

	return sprintf(buf, "%d\n", calculate_pci_freq(data));
	}

	static ssize_t show_pci_clock_sel(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	struct ics932s401_data *data = ics932s401_update_device(dev);
	int freq;

	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
	freq = calculate_pci_freq(data);
	else
	freq = 33333;

	return sprintf(buf, "%d\n", freq);
	}

	static ssize_t show_value(struct device *dev,
	struct device_attribute *devattr,
	char *buf);

	static ssize_t show_spread(struct device *dev,
	struct device_attribute *devattr,
	char *buf);

	static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
	static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
	static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
	static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
	static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
	static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
	static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
	static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
	static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
	static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
	static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);

	static struct attribute *ics932s401_attr[] =
	{
	&dev_attr_spread_enabled.attr,
	&dev_attr_cpu_clock_selection.attr,
	&dev_attr_cpu_clock.attr,
	&dev_attr_src_clock_selection.attr,
	&dev_attr_src_clock.attr,
	&dev_attr_pci_clock_selection.attr,
	&dev_attr_pci_clock.attr,
	&dev_attr_usb_clock.attr,
	&dev_attr_ref_clock.attr,
	&dev_attr_cpu_spread.attr,
	&dev_attr_src_spread.attr,
	NULL
	};

	static ssize_t show_value(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	int x;

	if (devattr == &dev_attr_usb_clock)
	x = 48000;
	else if (devattr == &dev_attr_ref_clock)
	x = BASE_CLOCK;
	else
	BUG();

	return sprintf(buf, "%d\n", x);
	}

	static ssize_t show_spread(struct device *dev,
	struct device_attribute *devattr,
	char *buf)
	{
	struct ics932s401_data *data = ics932s401_update_device(dev);
	int reg;
	unsigned long val;

	if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
	return sprintf(buf, "0%%\n");

	if (devattr == &dev_attr_src_spread)
	reg = ICS932S401_REG_SRC_SPREAD1;
	else if (devattr == &dev_attr_cpu_spread)
	reg = ICS932S401_REG_CPU_SPREAD1;
	else
	BUG();

	val = data->regs[reg] \| (data->regs[reg + 1] << 8);
	val &= ICS932S401_SPREAD_MASK;

	/* Scale 0..2^14 to -0.5. */
	val = 500000 * val / 16384;
	return sprintf(buf, "-0.%lu%%\n", val);
	}

	/* Return 0 if detection is successful, -ENODEV otherwise */
	static int ics932s401_detect(struct i2c_client *client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = client->adapter;
	int vendor, device, revision;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
	return -ENODEV;

	vendor = i2c_smbus_read_word_data(client, ICS932S401_REG_VENDOR_REV);
	vendor >>= 8;
	revision = vendor >> ICS932S401_REV_SHIFT;
	vendor &= ICS932S401_VENDOR_MASK;
	if (vendor != ICS932S401_VENDOR)
	return -ENODEV;

	device = i2c_smbus_read_word_data(client, ICS932S401_REG_DEVICE);
	device >>= 8;
	if (device != ICS932S401_DEVICE)
	return -ENODEV;

	if (revision != ICS932S401_REV)
	dev_info(&adapter->dev, "Unknown revision %d\n", revision);

	strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);

	return 0;
	}

	static int ics932s401_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct ics932s401_data *data;
	int err;

	data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
	if (!data) {
	err = -ENOMEM;
	goto exit;
	}

	i2c_set_clientdata(client, data);
	mutex_init(&data->lock);

	dev_info(&client->dev, "%s chip found\n", client->name);

	/* Register sysfs hooks */
	data->attrs.attrs = ics932s401_attr;
	err = sysfs_create_group(&client->dev.kobj, &data->attrs);
	if (err)
	goto exit_free;

	return 0;

	exit_free:
	kfree(data);
	exit:
	return err;
	}

	static int ics932s401_remove(struct i2c_client *client)
	{
	struct ics932s401_data *data = i2c_get_clientdata(client);

	sysfs_remove_group(&client->dev.kobj, &data->attrs);
	kfree(data);
	return 0;
	}

	static int __init ics932s401_init(void)
	{
	return i2c_add_driver(&ics932s401_driver);
	}

	static void __exit ics932s401_exit(void)
	{
	i2c_del_driver(&ics932s401_driver);
	}

	MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
	MODULE_DESCRIPTION("ICS932S401 driver");
	MODULE_LICENSE("GPL");

	module_init(ics932s401_init);
	module_exit(ics932s401_exit);

	/* IBM IntelliStation Z30 */
	MODULE_ALIAS("dmi:bvnIBM::rn9228:");
	MODULE_ALIAS("dmi:bvnIBM::rn9232:");

	/* IBM x3650/x3550 */
	MODULE_ALIAS("dmi:bvnIBM::pnIBMSystemx3650");
	MODULE_ALIAS("dmi:bvnIBM::pnIBMSystemx3550");