[net-next-2.6.git] / drivers / hwmon / lm92.c

/*
 * lm92 - Hardware monitoring driver
 * Copyright (C) 2005-2008  Jean Delvare <khali@linux-fr.org>
 *
 * Based on the lm90 driver, with some ideas taken from the lm_sensors
 * lm92 driver as well.
 *
 * The LM92 is a sensor chip made by National Semiconductor. It reports
 * its own temperature with a 0.0625 deg resolution and a 0.33 deg
 * accuracy. Complete datasheet can be obtained from National's website
 * at:
 *   http://www.national.com/pf/LM/LM92.html
 *
 * This driver also supports the MAX6635 sensor chip made by Maxim.
 * This chip is compatible with the LM92, but has a lesser accuracy
 * (1.0 deg). Complete datasheet can be obtained from Maxim's website
 * at:
 *   http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074
 *
 * Since the LM92 was the first chipset supported by this driver, most
 * comments will refer to this chipset, but are actually general and
 * concern all supported chipsets, unless mentioned otherwise.
 *
 * Support could easily be added for the National Semiconductor LM76
 * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible
 * with the LM92.
 *
 * 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/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>

/* The LM92 and MAX6635 have 2 two-state pins for address selection,
   resulting in 4 possible addresses. */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
						I2C_CLIENT_END };

/* The LM92 registers */
#define LM92_REG_CONFIG			0x01 /* 8-bit, RW */
#define LM92_REG_TEMP			0x00 /* 16-bit, RO */
#define LM92_REG_TEMP_HYST		0x02 /* 16-bit, RW */
#define LM92_REG_TEMP_CRIT		0x03 /* 16-bit, RW */
#define LM92_REG_TEMP_LOW		0x04 /* 16-bit, RW */
#define LM92_REG_TEMP_HIGH		0x05 /* 16-bit, RW */
#define LM92_REG_MAN_ID			0x07 /* 16-bit, RO, LM92 only */

/* The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
   left-justified in 16-bit registers. No rounding is done, with such
   a resolution it's just not worth it. Note that the MAX6635 doesn't
   make use of the 4 lower bits for limits (i.e. effective resolution
   for limits is 1 degree Celsius). */
static inline int TEMP_FROM_REG(s16 reg)
{
	return reg / 8 * 625 / 10;
}

static inline s16 TEMP_TO_REG(int val)
{
	if (val <= -60000)
		return -60000 * 10 / 625 * 8;
	if (val >= 160000)
		return 160000 * 10 / 625 * 8;
	return val * 10 / 625 * 8;
}

/* Alarm flags are stored in the 3 LSB of the temperature register */
static inline u8 ALARMS_FROM_REG(s16 reg)
{
	return reg & 0x0007;
}

/* Driver data (common to all clients) */
static struct i2c_driver lm92_driver;

/* Client data (each client gets its own) */
struct lm92_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* registers values */
	s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst;
};


/*
 * Sysfs attributes and callback functions
 */

static struct lm92_data *lm92_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm92_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ)
	 || !data->valid) {
		dev_dbg(&client->dev, "Updating lm92 data\n");
		data->temp1_input = swab16(i2c_smbus_read_word_data(client,
				    LM92_REG_TEMP));
		data->temp1_hyst = swab16(i2c_smbus_read_word_data(client,
				    LM92_REG_TEMP_HYST));
		data->temp1_crit = swab16(i2c_smbus_read_word_data(client,
				    LM92_REG_TEMP_CRIT));
		data->temp1_min = swab16(i2c_smbus_read_word_data(client,
				    LM92_REG_TEMP_LOW));
		data->temp1_max = swab16(i2c_smbus_read_word_data(client,
				    LM92_REG_TEMP_HIGH));

		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

#define show_temp(value) \
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
	struct lm92_data *data = lm92_update_device(dev); \
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
}
show_temp(temp1_input);
show_temp(temp1_crit);
show_temp(temp1_min);
show_temp(temp1_max);

#define set_temp(value, reg) \
static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \
	size_t count) \
{ \
	struct i2c_client *client = to_i2c_client(dev); \
	struct lm92_data *data = i2c_get_clientdata(client); \
	long val = simple_strtol(buf, NULL, 10); \
 \
	mutex_lock(&data->update_lock); \
	data->value = TEMP_TO_REG(val); \
	i2c_smbus_write_word_data(client, reg, swab16(data->value)); \
	mutex_unlock(&data->update_lock); \
	return count; \
}
set_temp(temp1_crit, LM92_REG_TEMP_CRIT);
set_temp(temp1_min, LM92_REG_TEMP_LOW);
set_temp(temp1_max, LM92_REG_TEMP_HIGH);

static ssize_t show_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct lm92_data *data = lm92_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit)
		       - TEMP_FROM_REG(data->temp1_hyst));
}
static ssize_t show_temp1_max_hyst(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct lm92_data *data = lm92_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max)
		       - TEMP_FROM_REG(data->temp1_hyst));
}
static ssize_t show_temp1_min_hyst(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct lm92_data *data = lm92_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min)
		       + TEMP_FROM_REG(data->temp1_hyst));
}

static ssize_t set_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf,
	size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm92_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val;
	i2c_smbus_write_word_data(client, LM92_REG_TEMP_HYST,
				  swab16(TEMP_TO_REG(data->temp1_hyst)));
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct lm92_data *data = lm92_update_device(dev);
	return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input));
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	int bitnr = to_sensor_dev_attr(attr)->index;
	struct lm92_data *data = lm92_update_device(dev);
	return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1);
}

static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL);
static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit,
	set_temp1_crit);
static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst,
	set_temp1_crit_hyst);
static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min,
	set_temp1_min);
static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL);
static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max,
	set_temp1_max);
static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL);
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);


/*
 * Detection and registration
 */

static void lm92_init_client(struct i2c_client *client)
{
	u8 config;

	/* Start the conversions if needed */
	config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
	if (config & 0x01)
		i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
					  config & 0xFE);
}

/* The MAX6635 has no identification register, so we have to use tricks
   to identify it reliably. This is somewhat slow.
   Note that we do NOT rely on the 2 MSB of the configuration register
   always reading 0, as suggested by the datasheet, because it was once
   reported not to be true. */
static int max6635_check(struct i2c_client *client)
{
	u16 temp_low, temp_high, temp_hyst, temp_crit;
	u8 conf;
	int i;

	/* No manufacturer ID register, so a read from this address will
	   always return the last read value. */
	temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
	if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
		return 0;
	temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
	if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
		return 0;
	
	/* Limits are stored as integer values (signed, 9-bit). */
	if ((temp_low & 0x7f00) || (temp_high & 0x7f00))
		return 0;
	temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
	temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
	if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00))
		return 0;

	/* Registers addresses were found to cycle over 16-byte boundaries.
	   We don't test all registers with all offsets so as to save some
	   reads and time, but this should still be sufficient to dismiss
	   non-MAX6635 chips. */
	conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
	for (i=16; i<96; i*=2) {
		if (temp_hyst != i2c_smbus_read_word_data(client,
		 		 LM92_REG_TEMP_HYST + i - 16)
		 || temp_crit != i2c_smbus_read_word_data(client,
		 		 LM92_REG_TEMP_CRIT + i)
		 || temp_low != i2c_smbus_read_word_data(client,
				LM92_REG_TEMP_LOW + i + 16)
		 || temp_high != i2c_smbus_read_word_data(client,
		 		 LM92_REG_TEMP_HIGH + i + 32)
		 || conf != i2c_smbus_read_byte_data(client,
		 	    LM92_REG_CONFIG + i))
			return 0;
	}

	return 1;
}

static struct attribute *lm92_attributes[] = {
	&dev_attr_temp1_input.attr,
	&dev_attr_temp1_crit.attr,
	&dev_attr_temp1_crit_hyst.attr,
	&dev_attr_temp1_min.attr,
	&dev_attr_temp1_min_hyst.attr,
	&dev_attr_temp1_max.attr,
	&dev_attr_temp1_max_hyst.attr,
	&dev_attr_alarms.attr,
	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group lm92_group = {
	.attrs = lm92_attributes,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm92_detect(struct i2c_client *new_client,
		       struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = new_client->adapter;
	u8 config;
	u16 man_id;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
					    | I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

	config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
	man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);

	if ((config & 0xe0) == 0x00 && man_id == 0x0180)
		pr_info("lm92: Found National Semiconductor LM92 chip\n");
	else if (max6635_check(new_client))
		pr_info("lm92: Found Maxim MAX6635 chip\n");
	else
		return -ENODEV;

	strlcpy(info->type, "lm92", I2C_NAME_SIZE);

	return 0;
}

static int lm92_probe(struct i2c_client *new_client,
		      const struct i2c_device_id *id)
{
	struct lm92_data *data;
	int err;

	data = kzalloc(sizeof(struct lm92_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto exit;
	}

	i2c_set_clientdata(new_client, data);
	data->valid = 0;
	mutex_init(&data->update_lock);

	/* Initialize the chipset */
	lm92_init_client(new_client);

	/* Register sysfs hooks */
	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm92_group)))
		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;
	}

	return 0;

exit_remove:
	sysfs_remove_group(&new_client->dev.kobj, &lm92_group);
exit_free:
	kfree(data);
exit:
	return err;
}

static int lm92_remove(struct i2c_client *client)
{
	struct lm92_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &lm92_group);

	kfree(data);
	return 0;
}


/*
 * Module and driver stuff
 */

static const struct i2c_device_id lm92_id[] = {
	{ "lm92", 0 },
	/* max6635 could be added here */
	{ }
};
MODULE_DEVICE_TABLE(i2c, lm92_id);

static struct i2c_driver lm92_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "lm92",
	},
	.probe		= lm92_probe,
	.remove		= lm92_remove,
	.id_table	= lm92_id,
	.detect		= lm92_detect,
	.address_list	= normal_i2c,
};

static int __init sensors_lm92_init(void)
{
	return i2c_add_driver(&lm92_driver);
}

static void __exit sensors_lm92_exit(void)
{
	i2c_del_driver(&lm92_driver);
}

MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("LM92/MAX6635 driver");
MODULE_LICENSE("GPL");

module_init(sensors_lm92_init);
module_exit(sensors_lm92_exit);
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* lm92 - Hardware monitoring driver
910e8dcf	3	* Copyright (C) 2005-2008 Jean Delvare <khali@linux-fr.org>
1da177e4 LT	4	*
	5	* Based on the lm90 driver, with some ideas taken from the lm_sensors
	6	* lm92 driver as well.
	7	*
	8	* The LM92 is a sensor chip made by National Semiconductor. It reports
	9	* its own temperature with a 0.0625 deg resolution and a 0.33 deg
	10	* accuracy. Complete datasheet can be obtained from National's website
	11	* at:
	12	* http://www.national.com/pf/LM/LM92.html
	13	*
	14	* This driver also supports the MAX6635 sensor chip made by Maxim.
	15	* This chip is compatible with the LM92, but has a lesser accuracy
	16	* (1.0 deg). Complete datasheet can be obtained from Maxim's website
	17	* at:
	18	* http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074
	19	*
	20	* Since the LM92 was the first chipset supported by this driver, most
	21	* comments will refer to this chipset, but are actually general and
	22	* concern all supported chipsets, unless mentioned otherwise.
	23	*
	24	* Support could easily be added for the National Semiconductor LM76
	25	* and Maxim MAX6633 and MAX6634 chips, which are mostly compatible
	26	* with the LM92.
	27	*
	28	* This program is free software; you can redistribute it and/or modify
	29	* it under the terms of the GNU General Public License as published by
	30	* the Free Software Foundation; either version 2 of the License, or
	31	* (at your option) any later version.
	32	*
	33	* This program is distributed in the hope that it will be useful,
	34	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	35	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	36	* GNU General Public License for more details.
	37	*
	38	* You should have received a copy of the GNU General Public License
	39	* along with this program; if not, write to the Free Software
	40	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	41	*/
	42
	43	#include <linux/module.h>
	44	#include <linux/init.h>
	45	#include <linux/slab.h>
	46	#include <linux/i2c.h>
943b0830	47	#include <linux/hwmon.h>
6cb59e91	48	#include <linux/hwmon-sysfs.h>
943b0830	49	#include <linux/err.h>
9a61bf63	50	#include <linux/mutex.h>
1da177e4 LT	51
	52	/* The LM92 and MAX6635 have 2 two-state pins for address selection,
	53	resulting in 4 possible addresses. */
25e9c86d MH	54	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
25e9c86d MH	55	I2C_CLIENT_END };
1da177e4	56
1da177e4 LT	57	/* The LM92 registers */
	58	#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
	59	#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
	60	#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
	61	#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
	62	#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
	63	#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
	64	#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
	65
	66	/* The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
	67	left-justified in 16-bit registers. No rounding is done, with such
	68	a resolution it's just not worth it. Note that the MAX6635 doesn't
	69	make use of the 4 lower bits for limits (i.e. effective resolution
	70	for limits is 1 degree Celsius). */
	71	static inline int TEMP_FROM_REG(s16 reg)
	72	{
	73	return reg / 8 * 625 / 10;
	74	}
	75
	76	static inline s16 TEMP_TO_REG(int val)
	77	{
	78	if (val <= -60000)
	79	return -60000 * 10 / 625 * 8;
	80	if (val >= 160000)
	81	return 160000 * 10 / 625 * 8;
	82	return val * 10 / 625 * 8;
	83	}
	84
	85	/* Alarm flags are stored in the 3 LSB of the temperature register */
	86	static inline u8 ALARMS_FROM_REG(s16 reg)
	87	{
	88	return reg & 0x0007;
	89	}
	90
	91	/* Driver data (common to all clients) */
	92	static struct i2c_driver lm92_driver;
	93
	94	/* Client data (each client gets its own) */
	95	struct lm92_data {
1beeffe4	96	struct device *hwmon_dev;
9a61bf63	97	struct mutex update_lock;
1da177e4 LT	98	char valid; /* zero until following fields are valid */
	99	unsigned long last_updated; /* in jiffies */
	100
	101	/* registers values */
	102	s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst;
	103	};
	104
	105
	106	/*
	107	* Sysfs attributes and callback functions
	108	*/
	109
	110	static struct lm92_data lm92_update_device(struct device dev)
	111	{
	112	struct i2c_client *client = to_i2c_client(dev);
	113	struct lm92_data *data = i2c_get_clientdata(client);
	114
9a61bf63	115	mutex_lock(&data->update_lock);
1da177e4 LT	116
	117	if (time_after(jiffies, data->last_updated + HZ)
	118	\|\| !data->valid) {
	119	dev_dbg(&client->dev, "Updating lm92 data\n");
	120	data->temp1_input = swab16(i2c_smbus_read_word_data(client,
	121	LM92_REG_TEMP));
	122	data->temp1_hyst = swab16(i2c_smbus_read_word_data(client,
	123	LM92_REG_TEMP_HYST));
	124	data->temp1_crit = swab16(i2c_smbus_read_word_data(client,
	125	LM92_REG_TEMP_CRIT));
	126	data->temp1_min = swab16(i2c_smbus_read_word_data(client,
	127	LM92_REG_TEMP_LOW));
	128	data->temp1_max = swab16(i2c_smbus_read_word_data(client,
	129	LM92_REG_TEMP_HIGH));
	130
	131	data->last_updated = jiffies;
	132	data->valid = 1;
	133	}
	134
9a61bf63	135	mutex_unlock(&data->update_lock);
1da177e4 LT	136
	137	return data;
	138	}
	139
	140	#define show_temp(value) \
8627f9ba	141	static ssize_t show_##value(struct device dev, struct device_attribute attr, char *buf) \
1da177e4 LT	142	{ \
	143	struct lm92_data *data = lm92_update_device(dev); \
	144	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
	145	}
	146	show_temp(temp1_input);
	147	show_temp(temp1_crit);
	148	show_temp(temp1_min);
	149	show_temp(temp1_max);
	150
	151	#define set_temp(value, reg) \
8627f9ba	152	static ssize_t set_##value(struct device dev, struct device_attribute attr, const char *buf, \
1da177e4 LT	153	size_t count) \
	154	{ \
	155	struct i2c_client *client = to_i2c_client(dev); \
	156	struct lm92_data *data = i2c_get_clientdata(client); \
	157	long val = simple_strtol(buf, NULL, 10); \
	158	\
9a61bf63	159	mutex_lock(&data->update_lock); \
1da177e4 LT	160	data->value = TEMP_TO_REG(val); \
1da177e4 LT	161	i2c_smbus_write_word_data(client, reg, swab16(data->value)); \
9a61bf63	162	mutex_unlock(&data->update_lock); \
1da177e4 LT	163	return count; \
	164	}
	165	set_temp(temp1_crit, LM92_REG_TEMP_CRIT);
	166	set_temp(temp1_min, LM92_REG_TEMP_LOW);
	167	set_temp(temp1_max, LM92_REG_TEMP_HIGH);
	168
8627f9ba	169	static ssize_t show_temp1_crit_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	170	{
	171	struct lm92_data *data = lm92_update_device(dev);
	172	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit)
	173	- TEMP_FROM_REG(data->temp1_hyst));
	174	}
8627f9ba	175	static ssize_t show_temp1_max_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	176	{
	177	struct lm92_data *data = lm92_update_device(dev);
	178	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max)
	179	- TEMP_FROM_REG(data->temp1_hyst));
	180	}
8627f9ba	181	static ssize_t show_temp1_min_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	182	{
	183	struct lm92_data *data = lm92_update_device(dev);
	184	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min)
	185	+ TEMP_FROM_REG(data->temp1_hyst));
	186	}
	187
8627f9ba	188	static ssize_t set_temp1_crit_hyst(struct device dev, struct device_attribute attr, const char *buf,
1da177e4 LT	189	size_t count)
	190	{
	191	struct i2c_client *client = to_i2c_client(dev);
	192	struct lm92_data *data = i2c_get_clientdata(client);
	193	long val = simple_strtol(buf, NULL, 10);
	194
9a61bf63	195	mutex_lock(&data->update_lock);
1da177e4 LT	196	data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val;
	197	i2c_smbus_write_word_data(client, LM92_REG_TEMP_HYST,
	198	swab16(TEMP_TO_REG(data->temp1_hyst)));
9a61bf63	199	mutex_unlock(&data->update_lock);
1da177e4 LT	200	return count;
	201	}
	202
8627f9ba	203	static ssize_t show_alarms(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	204	{
	205	struct lm92_data *data = lm92_update_device(dev);
	206	return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input));
	207	}
	208
6cb59e91 JD	209	static ssize_t show_alarm(struct device dev, struct device_attribute attr,
	210	char *buf)
	211	{
	212	int bitnr = to_sensor_dev_attr(attr)->index;
	213	struct lm92_data *data = lm92_update_device(dev);
	214	return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1);
	215	}
	216
1da177e4 LT	217	static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL);
	218	static DEVICE_ATTR(temp1_crit, S_IWUSR \| S_IRUGO, show_temp1_crit,
	219	set_temp1_crit);
	220	static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR \| S_IRUGO, show_temp1_crit_hyst,
	221	set_temp1_crit_hyst);
	222	static DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO, show_temp1_min,
	223	set_temp1_min);
	224	static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL);
	225	static DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO, show_temp1_max,
	226	set_temp1_max);
	227	static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL);
	228	static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
6cb59e91 JD	229	static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
	230	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
	231	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
1da177e4 LT	232
	233
	234	/*
	235	* Detection and registration
	236	*/
	237
	238	static void lm92_init_client(struct i2c_client *client)
	239	{
	240	u8 config;
	241
	242	/* Start the conversions if needed */
	243	config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
	244	if (config & 0x01)
	245	i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
	246	config & 0xFE);
	247	}
	248
	249	/* The MAX6635 has no identification register, so we have to use tricks
	250	to identify it reliably. This is somewhat slow.
	251	Note that we do NOT rely on the 2 MSB of the configuration register
	252	always reading 0, as suggested by the datasheet, because it was once
	253	reported not to be true. */
	254	static int max6635_check(struct i2c_client *client)
	255	{
	256	u16 temp_low, temp_high, temp_hyst, temp_crit;
	257	u8 conf;
	258	int i;
	259
	260	/* No manufacturer ID register, so a read from this address will
	261	always return the last read value. */
	262	temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
	263	if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
	264	return 0;
	265	temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
	266	if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
	267	return 0;
	268
	269	/* Limits are stored as integer values (signed, 9-bit). */
	270	if ((temp_low & 0x7f00) \|\| (temp_high & 0x7f00))
	271	return 0;
	272	temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
	273	temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
	274	if ((temp_hyst & 0x7f00) \|\| (temp_crit & 0x7f00))
	275	return 0;
	276
	277	/* Registers addresses were found to cycle over 16-byte boundaries.
	278	We don't test all registers with all offsets so as to save some
	279	reads and time, but this should still be sufficient to dismiss
	280	non-MAX6635 chips. */
	281	conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
	282	for (i=16; i<96; i*=2) {
	283	if (temp_hyst != i2c_smbus_read_word_data(client,
	284	LM92_REG_TEMP_HYST + i - 16)
	285	\|\| temp_crit != i2c_smbus_read_word_data(client,
	286	LM92_REG_TEMP_CRIT + i)
	287	\|\| temp_low != i2c_smbus_read_word_data(client,
	288	LM92_REG_TEMP_LOW + i + 16)
	289	\|\| temp_high != i2c_smbus_read_word_data(client,
	290	LM92_REG_TEMP_HIGH + i + 32)
	291	\|\| conf != i2c_smbus_read_byte_data(client,
	292	LM92_REG_CONFIG + i))
	293	return 0;
	294	}
	295
296	return 1;
297	}
298
0501a381 MH	299	static struct attribute *lm92_attributes[] = {
	300	&dev_attr_temp1_input.attr,
	301	&dev_attr_temp1_crit.attr,
	302	&dev_attr_temp1_crit_hyst.attr,
	303	&dev_attr_temp1_min.attr,
	304	&dev_attr_temp1_min_hyst.attr,
	305	&dev_attr_temp1_max.attr,
	306	&dev_attr_temp1_max_hyst.attr,
	307	&dev_attr_alarms.attr,
6cb59e91 JD	308	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	309	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	310	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
0501a381 MH	311	NULL
	312	};
	313
	314	static const struct attribute_group lm92_group = {
	315	.attrs = lm92_attributes,
	316	};
	317
910e8dcf	318	/* Return 0 if detection is successful, -ENODEV otherwise */
310ec792	319	static int lm92_detect(struct i2c_client *new_client,
910e8dcf	320	struct i2c_board_info *info)
1da177e4	321	{
910e8dcf	322	struct i2c_adapter *adapter = new_client->adapter;
52df6440 JD	323	u8 config;
52df6440 JD	324	u16 man_id;
1da177e4 LT	325
	326	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
	327	\| I2C_FUNC_SMBUS_WORD_DATA))
910e8dcf	328	return -ENODEV;
1da177e4	329
52df6440 JD	330	config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
	331	man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);
	332
	333	if ((config & 0xe0) == 0x00 && man_id == 0x0180)
	334	pr_info("lm92: Found National Semiconductor LM92 chip\n");
	335	else if (max6635_check(new_client))
	336	pr_info("lm92: Found Maxim MAX6635 chip\n");
	337	else
	338	return -ENODEV;
1da177e4	339
910e8dcf JD	340	strlcpy(info->type, "lm92", I2C_NAME_SIZE);
	341
	342	return 0;
	343	}
	344
	345	static int lm92_probe(struct i2c_client *new_client,
	346	const struct i2c_device_id *id)
	347	{
	348	struct lm92_data *data;
	349	int err;
	350
	351	data = kzalloc(sizeof(struct lm92_data), GFP_KERNEL);
	352	if (!data) {
	353	err = -ENOMEM;
	354	goto exit;
	355	}
	356
	357	i2c_set_clientdata(new_client, data);
1da177e4	358	data->valid = 0;
9a61bf63	359	mutex_init(&data->update_lock);
1da177e4	360
1da177e4 LT	361	/* Initialize the chipset */
	362	lm92_init_client(new_client);
	363
	364	/* Register sysfs hooks */
0501a381	365	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm92_group)))
910e8dcf	366	goto exit_free;
0501a381	367
1beeffe4 TJ	368	data->hwmon_dev = hwmon_device_register(&new_client->dev);
	369	if (IS_ERR(data->hwmon_dev)) {
	370	err = PTR_ERR(data->hwmon_dev);
0501a381	371	goto exit_remove;
943b0830 MH	372	}
943b0830 MH	373
1da177e4 LT	374	return 0;
1da177e4 LT	375
0501a381 MH	376	exit_remove:
0501a381 MH	377	sysfs_remove_group(&new_client->dev.kobj, &lm92_group);
1da177e4 LT	378	exit_free:
	379	kfree(data);
	380	exit:
	381	return err;
	382	}
	383
910e8dcf	384	static int lm92_remove(struct i2c_client *client)
1da177e4	385	{
943b0830	386	struct lm92_data *data = i2c_get_clientdata(client);
1da177e4	387
1beeffe4	388	hwmon_device_unregister(data->hwmon_dev);
0501a381	389	sysfs_remove_group(&client->dev.kobj, &lm92_group);
943b0830	390
943b0830	391	kfree(data);
1da177e4 LT	392	return 0;
	393	}
	394
	395
	396	/*
	397	* Module and driver stuff
	398	*/
	399
910e8dcf	400	static const struct i2c_device_id lm92_id[] = {
1f86df49	401	{ "lm92", 0 },
910e8dcf JD	402	/* max6635 could be added here */
	403	{ }
	404	};
	405	MODULE_DEVICE_TABLE(i2c, lm92_id);
	406
1da177e4	407	static struct i2c_driver lm92_driver = {
910e8dcf	408	.class = I2C_CLASS_HWMON,
cdaf7934	409	.driver = {
cdaf7934 LR	410	.name = "lm92",
cdaf7934 LR	411	},
910e8dcf JD	412	.probe = lm92_probe,
	413	.remove = lm92_remove,
	414	.id_table = lm92_id,
	415	.detect = lm92_detect,
c3813d6a	416	.address_list = normal_i2c,
1da177e4 LT	417	};
	418
	419	static int __init sensors_lm92_init(void)
	420	{
	421	return i2c_add_driver(&lm92_driver);
	422	}
	423
	424	static void __exit sensors_lm92_exit(void)
	425	{
	426	i2c_del_driver(&lm92_driver);
	427	}
	428
	429	MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
	430	MODULE_DESCRIPTION("LM92/MAX6635 driver");
	431	MODULE_LICENSE("GPL");
	432
	433	module_init(sensors_lm92_init);
	434	module_exit(sensors_lm92_exit);