[mirror_ubuntu-artful-kernel.git] / drivers / hwmon / lm92.c

/*
 * lm92 - Hardware monitoring driver
 * Copyright (C) 2005  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/i2c-sensor.h>
#include <linux/hwmon.h>
#include <linux/err.h>

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

/* Insmod parameters */
SENSORS_INSMOD_1(lm92);

/* 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 i2c_client client;
	struct class_device *class_dev;
	struct semaphore 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);

	down(&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;
	}

	up(&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); \
 \
	down(&data->update_lock); \
	data->value = TEMP_TO_REG(val); \
	i2c_smbus_write_word_data(client, reg, swab16(data->value)); \
	up(&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);

	down(&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)));
	up(&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 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);


/*
 * 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;
}

/* The following function does more than just detection. If detection
   succeeds, it also registers the new chip. */
static int lm92_detect(struct i2c_adapter *adapter, int address, int kind)
{
	struct i2c_client *new_client;
	struct lm92_data *data;
	int err = 0;
	char *name;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
					    | I2C_FUNC_SMBUS_WORD_DATA))
		goto exit;

	if (!(data = kmalloc(sizeof(struct lm92_data), GFP_KERNEL))) {
		err = -ENOMEM;
		goto exit;
	}
	memset(data, 0, sizeof(struct lm92_data));

	/* Fill in enough client fields so that we can read from the chip,
	   which is required for identication */
	new_client = &data->client;
	i2c_set_clientdata(new_client, data);
	new_client->addr = address;
	new_client->adapter = adapter;
	new_client->driver = &lm92_driver;
	new_client->flags = 0;

	/* A negative kind means that the driver was loaded with no force
	   parameter (default), so we must identify the chip. */
	if (kind < 0) {
		u8 config = i2c_smbus_read_byte_data(new_client,
			     LM92_REG_CONFIG);
		u16 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");
	 		kind = lm92;
		} else
		if (max6635_check(new_client)) {
			pr_info("lm92: Found Maxim MAX6635 chip\n");
			kind = lm92; /* No separate prefix */
		}
		else
			goto exit_free;
	} else
	if (kind == 0) /* Default to an LM92 if forced */
		kind = lm92;

	/* Give it the proper name */
	if (kind == lm92) {
		name = "lm92";
	} else { /* Supposedly cannot happen */
		dev_dbg(&new_client->dev, "Kind out of range?\n");
		goto exit_free;
	}

	/* Fill in the remaining client fields */
	strlcpy(new_client->name, name, I2C_NAME_SIZE);
	data->valid = 0;
	init_MUTEX(&data->update_lock);

	/* Tell the i2c subsystem a new client has arrived */
	if ((err = i2c_attach_client(new_client)))
		goto exit_free;

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

	/* Register sysfs hooks */
	data->class_dev = hwmon_device_register(&new_client->dev);
	if (IS_ERR(data->class_dev)) {
		err = PTR_ERR(data->class_dev);
		goto exit_detach;
	}

	device_create_file(&new_client->dev, &dev_attr_temp1_input);
	device_create_file(&new_client->dev, &dev_attr_temp1_crit);
	device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst);
	device_create_file(&new_client->dev, &dev_attr_temp1_min);
	device_create_file(&new_client->dev, &dev_attr_temp1_min_hyst);
	device_create_file(&new_client->dev, &dev_attr_temp1_max);
	device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
	device_create_file(&new_client->dev, &dev_attr_alarms);

	return 0;

exit_detach:
	i2c_detach_client(new_client);
exit_free:
	kfree(data);
exit:
	return err;
}

static int lm92_attach_adapter(struct i2c_adapter *adapter)
{
	if (!(adapter->class & I2C_CLASS_HWMON))
		return 0;
	return i2c_detect(adapter, &addr_data, lm92_detect);
}

static int lm92_detach_client(struct i2c_client *client)
{
	struct lm92_data *data = i2c_get_clientdata(client);
	int err;

	hwmon_device_unregister(data->class_dev);

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

	kfree(data);
	return 0;
}


/*
 * Module and driver stuff
 */

static struct i2c_driver lm92_driver = {
	.owner		= THIS_MODULE,
	.name		= "lm92",
	.id		= I2C_DRIVERID_LM92,
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter	= lm92_attach_adapter,
	.detach_client	= lm92_detach_client,
};

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	/*
	2	* lm92 - Hardware monitoring driver
	3	* Copyright (C) 2005 Jean Delvare <khali@linux-fr.org>
	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>
	47	#include <linux/i2c-sensor.h>
943b0830 MH	48	#include <linux/hwmon.h>
943b0830 MH	49	#include <linux/err.h>
1da177e4 LT	50
	51	/* The LM92 and MAX6635 have 2 two-state pins for address selection,
	52	resulting in 4 possible addresses. */
	53	static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
	54	I2C_CLIENT_END };
1da177e4 LT	55
	56	/* Insmod parameters */
	57	SENSORS_INSMOD_1(lm92);
	58
	59	/* The LM92 registers */
	60	#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
	61	#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
	62	#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
	63	#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
	64	#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
	65	#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
	66	#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
	67
	68	/* The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
	69	left-justified in 16-bit registers. No rounding is done, with such
	70	a resolution it's just not worth it. Note that the MAX6635 doesn't
	71	make use of the 4 lower bits for limits (i.e. effective resolution
	72	for limits is 1 degree Celsius). */
	73	static inline int TEMP_FROM_REG(s16 reg)
	74	{
	75	return reg / 8 * 625 / 10;
	76	}
	77
	78	static inline s16 TEMP_TO_REG(int val)
	79	{
	80	if (val <= -60000)
	81	return -60000 * 10 / 625 * 8;
	82	if (val >= 160000)
	83	return 160000 * 10 / 625 * 8;
	84	return val * 10 / 625 * 8;
	85	}
	86
	87	/* Alarm flags are stored in the 3 LSB of the temperature register */
	88	static inline u8 ALARMS_FROM_REG(s16 reg)
	89	{
	90	return reg & 0x0007;
	91	}
	92
	93	/* Driver data (common to all clients) */
	94	static struct i2c_driver lm92_driver;
	95
	96	/* Client data (each client gets its own) */
	97	struct lm92_data {
	98	struct i2c_client client;
943b0830	99	struct class_device *class_dev;
1da177e4 LT	100	struct semaphore update_lock;
	101	char valid; /* zero until following fields are valid */
	102	unsigned long last_updated; /* in jiffies */
	103
	104	/* registers values */
	105	s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst;
	106	};
	107
	108
	109	/*
	110	* Sysfs attributes and callback functions
	111	*/
	112
	113	static struct lm92_data lm92_update_device(struct device dev)
	114	{
	115	struct i2c_client *client = to_i2c_client(dev);
	116	struct lm92_data *data = i2c_get_clientdata(client);
	117
	118	down(&data->update_lock);
	119
	120	if (time_after(jiffies, data->last_updated + HZ)
	121	\|\| !data->valid) {
	122	dev_dbg(&client->dev, "Updating lm92 data\n");
	123	data->temp1_input = swab16(i2c_smbus_read_word_data(client,
	124	LM92_REG_TEMP));
	125	data->temp1_hyst = swab16(i2c_smbus_read_word_data(client,
	126	LM92_REG_TEMP_HYST));
	127	data->temp1_crit = swab16(i2c_smbus_read_word_data(client,
	128	LM92_REG_TEMP_CRIT));
	129	data->temp1_min = swab16(i2c_smbus_read_word_data(client,
	130	LM92_REG_TEMP_LOW));
	131	data->temp1_max = swab16(i2c_smbus_read_word_data(client,
	132	LM92_REG_TEMP_HIGH));
	133
	134	data->last_updated = jiffies;
	135	data->valid = 1;
	136	}
	137
	138	up(&data->update_lock);
	139
	140	return data;
	141	}
	142
	143	#define show_temp(value) \
8627f9ba	144	static ssize_t show_##value(struct device dev, struct device_attribute attr, char *buf) \
1da177e4 LT	145	{ \
	146	struct lm92_data *data = lm92_update_device(dev); \
	147	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
	148	}
	149	show_temp(temp1_input);
	150	show_temp(temp1_crit);
	151	show_temp(temp1_min);
	152	show_temp(temp1_max);
	153
	154	#define set_temp(value, reg) \
8627f9ba	155	static ssize_t set_##value(struct device dev, struct device_attribute attr, const char *buf, \
1da177e4 LT	156	size_t count) \
	157	{ \
	158	struct i2c_client *client = to_i2c_client(dev); \
	159	struct lm92_data *data = i2c_get_clientdata(client); \
	160	long val = simple_strtol(buf, NULL, 10); \
	161	\
	162	down(&data->update_lock); \
	163	data->value = TEMP_TO_REG(val); \
	164	i2c_smbus_write_word_data(client, reg, swab16(data->value)); \
	165	up(&data->update_lock); \
	166	return count; \
	167	}
	168	set_temp(temp1_crit, LM92_REG_TEMP_CRIT);
	169	set_temp(temp1_min, LM92_REG_TEMP_LOW);
	170	set_temp(temp1_max, LM92_REG_TEMP_HIGH);
	171
8627f9ba	172	static ssize_t show_temp1_crit_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	173	{
	174	struct lm92_data *data = lm92_update_device(dev);
	175	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit)
	176	- TEMP_FROM_REG(data->temp1_hyst));
	177	}
8627f9ba	178	static ssize_t show_temp1_max_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	179	{
	180	struct lm92_data *data = lm92_update_device(dev);
	181	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max)
	182	- TEMP_FROM_REG(data->temp1_hyst));
	183	}
8627f9ba	184	static ssize_t show_temp1_min_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	185	{
	186	struct lm92_data *data = lm92_update_device(dev);
	187	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min)
	188	+ TEMP_FROM_REG(data->temp1_hyst));
	189	}
	190
8627f9ba	191	static ssize_t set_temp1_crit_hyst(struct device dev, struct device_attribute attr, const char *buf,
1da177e4 LT	192	size_t count)
	193	{
	194	struct i2c_client *client = to_i2c_client(dev);
	195	struct lm92_data *data = i2c_get_clientdata(client);
	196	long val = simple_strtol(buf, NULL, 10);
	197
	198	down(&data->update_lock);
	199	data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val;
	200	i2c_smbus_write_word_data(client, LM92_REG_TEMP_HYST,
	201	swab16(TEMP_TO_REG(data->temp1_hyst)));
	202	up(&data->update_lock);
	203	return count;
	204	}
	205
8627f9ba	206	static ssize_t show_alarms(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	207	{
	208	struct lm92_data *data = lm92_update_device(dev);
	209	return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input));
	210	}
	211
	212	static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL);
	213	static DEVICE_ATTR(temp1_crit, S_IWUSR \| S_IRUGO, show_temp1_crit,
	214	set_temp1_crit);
	215	static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR \| S_IRUGO, show_temp1_crit_hyst,
	216	set_temp1_crit_hyst);
	217	static DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO, show_temp1_min,
	218	set_temp1_min);
	219	static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL);
	220	static DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO, show_temp1_max,
	221	set_temp1_max);
	222	static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL);
	223	static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
	224
	225
	226	/*
	227	* Detection and registration
	228	*/
	229
	230	static void lm92_init_client(struct i2c_client *client)
	231	{
	232	u8 config;
	233
	234	/* Start the conversions if needed */
	235	config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
	236	if (config & 0x01)
	237	i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
	238	config & 0xFE);
	239	}
	240
	241	/* The MAX6635 has no identification register, so we have to use tricks
	242	to identify it reliably. This is somewhat slow.
	243	Note that we do NOT rely on the 2 MSB of the configuration register
	244	always reading 0, as suggested by the datasheet, because it was once
	245	reported not to be true. */
	246	static int max6635_check(struct i2c_client *client)
	247	{
	248	u16 temp_low, temp_high, temp_hyst, temp_crit;
	249	u8 conf;
	250	int i;
	251
	252	/* No manufacturer ID register, so a read from this address will
	253	always return the last read value. */
	254	temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
	255	if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
	256	return 0;
	257	temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
	258	if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
	259	return 0;
	260
	261	/* Limits are stored as integer values (signed, 9-bit). */
	262	if ((temp_low & 0x7f00) \|\| (temp_high & 0x7f00))
	263	return 0;
	264	temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
	265	temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
	266	if ((temp_hyst & 0x7f00) \|\| (temp_crit & 0x7f00))
	267	return 0;
	268
	269	/* Registers addresses were found to cycle over 16-byte boundaries.
	270	We don't test all registers with all offsets so as to save some
271	reads and time, but this should still be sufficient to dismiss
272	non-MAX6635 chips. */
273	conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
274	for (i=16; i<96; i*=2) {
275	if (temp_hyst != i2c_smbus_read_word_data(client,
276	LM92_REG_TEMP_HYST + i - 16)
277	\|\| temp_crit != i2c_smbus_read_word_data(client,
278	LM92_REG_TEMP_CRIT + i)
279	\|\| temp_low != i2c_smbus_read_word_data(client,
280	LM92_REG_TEMP_LOW + i + 16)
281	\|\| temp_high != i2c_smbus_read_word_data(client,
282	LM92_REG_TEMP_HIGH + i + 32)
283	\|\| conf != i2c_smbus_read_byte_data(client,
284	LM92_REG_CONFIG + i))
285	return 0;
286	}
287
288	return 1;
289	}
290
291	/* The following function does more than just detection. If detection
292	succeeds, it also registers the new chip. */
293	static int lm92_detect(struct i2c_adapter *adapter, int address, int kind)
294	{
295	struct i2c_client *new_client;
296	struct lm92_data *data;
297	int err = 0;
298	char *name;
299
300	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
301	\| I2C_FUNC_SMBUS_WORD_DATA))
302	goto exit;
303
304	if (!(data = kmalloc(sizeof(struct lm92_data), GFP_KERNEL))) {
305	err = -ENOMEM;
306	goto exit;
307	}
308	memset(data, 0, sizeof(struct lm92_data));
309
310	/* Fill in enough client fields so that we can read from the chip,
311	which is required for identication */
312	new_client = &data->client;
313	i2c_set_clientdata(new_client, data);
314	new_client->addr = address;
315	new_client->adapter = adapter;
316	new_client->driver = &lm92_driver;
317	new_client->flags = 0;
318
319	/* A negative kind means that the driver was loaded with no force
320	parameter (default), so we must identify the chip. */
321	if (kind < 0) {
322	u8 config = i2c_smbus_read_byte_data(new_client,
323	LM92_REG_CONFIG);
324	u16 man_id = i2c_smbus_read_word_data(new_client,
325	LM92_REG_MAN_ID);
326
327	if ((config & 0xe0) == 0x00
328	&& man_id == 0x0180) {
329	pr_info("lm92: Found National Semiconductor LM92 chip\n");
330	kind = lm92;
331	} else
332	if (max6635_check(new_client)) {
333	pr_info("lm92: Found Maxim MAX6635 chip\n");
334	kind = lm92; /* No separate prefix */
335	}
336	else
337	goto exit_free;
338	} else
339	if (kind == 0) /* Default to an LM92 if forced */
340	kind = lm92;
341
342	/* Give it the proper name */
343	if (kind == lm92) {
344	name = "lm92";
345	} else { /* Supposedly cannot happen */
346	dev_dbg(&new_client->dev, "Kind out of range?\n");
347	goto exit_free;
348	}
349
350	/* Fill in the remaining client fields */
351	strlcpy(new_client->name, name, I2C_NAME_SIZE);
352	data->valid = 0;
353	init_MUTEX(&data->update_lock);
354
355	/* Tell the i2c subsystem a new client has arrived */
356	if ((err = i2c_attach_client(new_client)))
357	goto exit_free;
358
359	/* Initialize the chipset */
360	lm92_init_client(new_client);
361
362	/* Register sysfs hooks */
943b0830 MH	363	data->class_dev = hwmon_device_register(&new_client->dev);
	364	if (IS_ERR(data->class_dev)) {
	365	err = PTR_ERR(data->class_dev);
	366	goto exit_detach;
	367	}
	368
1da177e4 LT	369	device_create_file(&new_client->dev, &dev_attr_temp1_input);
	370	device_create_file(&new_client->dev, &dev_attr_temp1_crit);
	371	device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst);
	372	device_create_file(&new_client->dev, &dev_attr_temp1_min);
	373	device_create_file(&new_client->dev, &dev_attr_temp1_min_hyst);
	374	device_create_file(&new_client->dev, &dev_attr_temp1_max);
	375	device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
	376	device_create_file(&new_client->dev, &dev_attr_alarms);
	377
	378	return 0;
	379
943b0830 MH	380	exit_detach:
943b0830 MH	381	i2c_detach_client(new_client);
1da177e4 LT	382	exit_free:
	383	kfree(data);
	384	exit:
	385	return err;
	386	}
	387
	388	static int lm92_attach_adapter(struct i2c_adapter *adapter)
	389	{
	390	if (!(adapter->class & I2C_CLASS_HWMON))
	391	return 0;
	392	return i2c_detect(adapter, &addr_data, lm92_detect);
	393	}
	394
	395	static int lm92_detach_client(struct i2c_client *client)
	396	{
943b0830	397	struct lm92_data *data = i2c_get_clientdata(client);
1da177e4 LT	398	int err;
1da177e4 LT	399
943b0830 MH	400	hwmon_device_unregister(data->class_dev);
943b0830 MH	401
7bef5594	402	if ((err = i2c_detach_client(client)))
1da177e4	403	return err;
1da177e4	404
943b0830	405	kfree(data);
1da177e4 LT	406	return 0;
	407	}
	408
	409
	410	/*
	411	* Module and driver stuff
	412	*/
	413
	414	static struct i2c_driver lm92_driver = {
	415	.owner = THIS_MODULE,
	416	.name = "lm92",
	417	.id = I2C_DRIVERID_LM92,
	418	.flags = I2C_DF_NOTIFY,
	419	.attach_adapter = lm92_attach_adapter,
	420	.detach_client = lm92_detach_client,
	421	};
	422
	423	static int __init sensors_lm92_init(void)
	424	{
	425	return i2c_add_driver(&lm92_driver);
	426	}
	427
	428	static void __exit sensors_lm92_exit(void)
	429	{
	430	i2c_del_driver(&lm92_driver);
	431	}
	432
	433	MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
	434	MODULE_DESCRIPTION("LM92/MAX6635 driver");
	435	MODULE_LICENSE("GPL");
	436
	437	module_init(sensors_lm92_init);
	438	module_exit(sensors_lm92_exit);