[linux-2.6-block.git] / drivers / hwmon / lm77.c

/*
    lm77.c - Part of lm_sensors, Linux kernel modules for hardware
             monitoring

    Copyright (c) 2004  Andras BALI <drewie@freemail.hu>

    Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>.  The LM77
    is a temperature sensor and thermal window comparator with 0.5 deg
    resolution made by National Semiconductor.  Complete datasheet can be
    obtained at their site:
       http://www.national.com/pf/LM/LM77.html

    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/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>

/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
						I2C_CLIENT_END };

/* Insmod parameters */
I2C_CLIENT_INSMOD_1(lm77);

/* The LM77 registers */
#define LM77_REG_TEMP		0x00
#define LM77_REG_CONF		0x01
#define LM77_REG_TEMP_HYST	0x02
#define LM77_REG_TEMP_CRIT	0x03
#define LM77_REG_TEMP_MIN	0x04
#define LM77_REG_TEMP_MAX	0x05

/* Each client has this additional data */
struct lm77_data {
	struct device 		*hwmon_dev;
	struct mutex		update_lock;
	char			valid;
	unsigned long		last_updated;	/* In jiffies */
	int			temp_input;	/* Temperatures */
	int			temp_crit;
	int			temp_min;
	int			temp_max;
	int			temp_hyst;
	u8			alarms;
};

static int lm77_probe(struct i2c_client *client,
		      const struct i2c_device_id *id);
static int lm77_detect(struct i2c_client *client, int kind,
		       struct i2c_board_info *info);
static void lm77_init_client(struct i2c_client *client);
static int lm77_remove(struct i2c_client *client);
static u16 lm77_read_value(struct i2c_client *client, u8 reg);
static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);

static struct lm77_data *lm77_update_device(struct device *dev);


static const struct i2c_device_id lm77_id[] = {
	{ "lm77", lm77 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lm77_id);

/* This is the driver that will be inserted */
static struct i2c_driver lm77_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "lm77",
	},
	.probe		= lm77_probe,
	.remove		= lm77_remove,
	.id_table	= lm77_id,
	.detect		= lm77_detect,
	.address_data	= &addr_data,
};

/* straight from the datasheet */
#define LM77_TEMP_MIN (-55000)
#define LM77_TEMP_MAX 125000

/* In the temperature registers, the low 3 bits are not part of the
   temperature values; they are the status bits. */
static inline s16 LM77_TEMP_TO_REG(int temp)
{
	int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
	return (ntemp / 500) * 8;
}

static inline int LM77_TEMP_FROM_REG(s16 reg)
{
	return (reg / 8) * 500;
}

/* sysfs stuff */

/* read routines for temperature limits */
#define show(value)	\
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)	\
{								\
	struct lm77_data *data = lm77_update_device(dev);	\
	return sprintf(buf, "%d\n", data->value);		\
}

show(temp_input);
show(temp_crit);
show(temp_min);
show(temp_max);

/* read routines for hysteresis values */
static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct lm77_data *data = lm77_update_device(dev);
	return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
}
static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct lm77_data *data = lm77_update_device(dev);
	return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
}
static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct lm77_data *data = lm77_update_device(dev);
	return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
}

/* write routines */
#define set(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 lm77_data *data = i2c_get_clientdata(client);			\
	long val = simple_strtol(buf, NULL, 10);				\
										\
	mutex_lock(&data->update_lock);						\
	data->value = val;				\
	lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value));		\
	mutex_unlock(&data->update_lock);					\
	return count;								\
}

set(temp_min, LM77_REG_TEMP_MIN);
set(temp_max, LM77_REG_TEMP_MAX);

/* hysteresis is stored as a relative value on the chip, so it has to be
   converted first */
static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm77_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->temp_hyst = data->temp_crit - val;
	lm77_write_value(client, LM77_REG_TEMP_HYST,
			 LM77_TEMP_TO_REG(data->temp_hyst));
	mutex_unlock(&data->update_lock);
	return count;
}

/* preserve hysteresis when setting T_crit */
static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm77_data *data = i2c_get_clientdata(client);
	long val = simple_strtoul(buf, NULL, 10);
	int oldcrithyst;
	
	mutex_lock(&data->update_lock);
	oldcrithyst = data->temp_crit - data->temp_hyst;
	data->temp_crit = val;
	data->temp_hyst = data->temp_crit - oldcrithyst;
	lm77_write_value(client, LM77_REG_TEMP_CRIT,
			 LM77_TEMP_TO_REG(data->temp_crit));
	lm77_write_value(client, LM77_REG_TEMP_HYST,
			 LM77_TEMP_TO_REG(data->temp_hyst));
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	int bitnr = to_sensor_dev_attr(attr)->index;
	struct lm77_data *data = lm77_update_device(dev);
	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
}

static DEVICE_ATTR(temp1_input, S_IRUGO,
		   show_temp_input, NULL);
static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
		   show_temp_crit, set_temp_crit);
static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
		   show_temp_min, set_temp_min);
static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
		   show_temp_max, set_temp_max);

static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
		   show_temp_crit_hyst, set_temp_crit_hyst);
static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
		   show_temp_min_hyst, NULL);
static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
		   show_temp_max_hyst, 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);

static struct attribute *lm77_attributes[] = {
	&dev_attr_temp1_input.attr,
	&dev_attr_temp1_crit.attr,
	&dev_attr_temp1_min.attr,
	&dev_attr_temp1_max.attr,
	&dev_attr_temp1_crit_hyst.attr,
	&dev_attr_temp1_min_hyst.attr,
	&dev_attr_temp1_max_hyst.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 lm77_group = {
	.attrs = lm77_attributes,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm77_detect(struct i2c_client *new_client, int kind,
		       struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = new_client->adapter;

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

	/* Here comes the remaining detection.  Since the LM77 has no
	   register dedicated to identification, we have to rely on the
	   following tricks:

	   1. the high 4 bits represent the sign and thus they should
	      always be the same
	   2. the high 3 bits are unused in the configuration register
	   3. addresses 0x06 and 0x07 return the last read value
	   4. registers cycling over 8-address boundaries

	   Word-sized registers are high-byte first. */
	if (kind < 0) {
		int i, cur, conf, hyst, crit, min, max;

		/* addresses cycling */
		cur = i2c_smbus_read_word_data(new_client, 0);
		conf = i2c_smbus_read_byte_data(new_client, 1);
		hyst = i2c_smbus_read_word_data(new_client, 2);
		crit = i2c_smbus_read_word_data(new_client, 3);
		min = i2c_smbus_read_word_data(new_client, 4);
		max = i2c_smbus_read_word_data(new_client, 5);
		for (i = 8; i <= 0xff; i += 8)
			if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
			    || i2c_smbus_read_word_data(new_client, i + 2) != hyst
			    || i2c_smbus_read_word_data(new_client, i + 3) != crit
			    || i2c_smbus_read_word_data(new_client, i + 4) != min
			    || i2c_smbus_read_word_data(new_client, i + 5) != max)
				return -ENODEV;

		/* sign bits */
		if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
		    || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
		    || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
		    || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
		    || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
			return -ENODEV;

		/* unused bits */
		if (conf & 0xe0)
			return -ENODEV;

		/* 0x06 and 0x07 return the last read value */
		cur = i2c_smbus_read_word_data(new_client, 0);
		if (i2c_smbus_read_word_data(new_client, 6) != cur
		    || i2c_smbus_read_word_data(new_client, 7) != cur)
			return -ENODEV;
		hyst = i2c_smbus_read_word_data(new_client, 2);
		if (i2c_smbus_read_word_data(new_client, 6) != hyst
		    || i2c_smbus_read_word_data(new_client, 7) != hyst)
			return -ENODEV;
		min = i2c_smbus_read_word_data(new_client, 4);
		if (i2c_smbus_read_word_data(new_client, 6) != min
		    || i2c_smbus_read_word_data(new_client, 7) != min)
			return -ENODEV;

	}

	strlcpy(info->type, "lm77", I2C_NAME_SIZE);

	return 0;
}

static int lm77_probe(struct i2c_client *new_client,
		      const struct i2c_device_id *id)
{
	struct lm77_data *data;
	int err;

	data = kzalloc(sizeof(struct lm77_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 LM77 chip */
	lm77_init_client(new_client);

	/* Register sysfs hooks */
	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_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, &lm77_group);
exit_free:
	kfree(data);
exit:
	return err;
}

static int lm77_remove(struct i2c_client *client)
{
	struct lm77_data *data = i2c_get_clientdata(client);
	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &lm77_group);
	kfree(data);
	return 0;
}

/* All registers are word-sized, except for the configuration register.
   The LM77 uses the high-byte first convention. */
static u16 lm77_read_value(struct i2c_client *client, u8 reg)
{
	if (reg == LM77_REG_CONF)
		return i2c_smbus_read_byte_data(client, reg);
	else
		return swab16(i2c_smbus_read_word_data(client, reg));
}

static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
{
	if (reg == LM77_REG_CONF)
		return i2c_smbus_write_byte_data(client, reg, value);
	else
		return i2c_smbus_write_word_data(client, reg, swab16(value));
}

static void lm77_init_client(struct i2c_client *client)
{
	/* Initialize the LM77 chip - turn off shutdown mode */
	int conf = lm77_read_value(client, LM77_REG_CONF);
	if (conf & 1)
		lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
}

static struct lm77_data *lm77_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm77_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	    || !data->valid) {
		dev_dbg(&client->dev, "Starting lm77 update\n");
		data->temp_input =
			LM77_TEMP_FROM_REG(lm77_read_value(client,
							   LM77_REG_TEMP));
		data->temp_hyst =
			LM77_TEMP_FROM_REG(lm77_read_value(client,
							   LM77_REG_TEMP_HYST));
		data->temp_crit =
			LM77_TEMP_FROM_REG(lm77_read_value(client,
							   LM77_REG_TEMP_CRIT));
		data->temp_min =
			LM77_TEMP_FROM_REG(lm77_read_value(client,
							   LM77_REG_TEMP_MIN));
		data->temp_max =
			LM77_TEMP_FROM_REG(lm77_read_value(client,
							   LM77_REG_TEMP_MAX));
		data->alarms =
			lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

static int __init sensors_lm77_init(void)
{
	return i2c_add_driver(&lm77_driver);
}

static void __exit sensors_lm77_exit(void)
{
	i2c_del_driver(&lm77_driver);
}

MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
MODULE_DESCRIPTION("LM77 driver");
MODULE_LICENSE("GPL");

module_init(sensors_lm77_init);
module_exit(sensors_lm77_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	lm77.c - Part of lm_sensors, Linux kernel modules for hardware
	3	monitoring
	4
	5	Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
	6
	7	Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77
	8	is a temperature sensor and thermal window comparator with 0.5 deg
	9	resolution made by National Semiconductor. Complete datasheet can be
	10	obtained at their site:
	11	http://www.national.com/pf/LM/LM77.html
	12
	13	This program is free software; you can redistribute it and/or modify
	14	it under the terms of the GNU General Public License as published by
	15	the Free Software Foundation; either version 2 of the License, or
	16	(at your option) any later version.
	17
	18	This program is distributed in the hope that it will be useful,
	19	but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	21	GNU General Public License for more details.
	22
	23	You should have received a copy of the GNU General Public License
	24	along with this program; if not, write to the Free Software
	25	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	26	*/
	27
1da177e4 LT	28	#include <linux/module.h>
	29	#include <linux/init.h>
	30	#include <linux/slab.h>
	31	#include <linux/jiffies.h>
	32	#include <linux/i2c.h>
943b0830	33	#include <linux/hwmon.h>
1f52af0f	34	#include <linux/hwmon-sysfs.h>
943b0830	35	#include <linux/err.h>
9a61bf63	36	#include <linux/mutex.h>
1da177e4 LT	37
1da177e4 LT	38	/* Addresses to scan */
25e9c86d MH	39	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
25e9c86d MH	40	I2C_CLIENT_END };
1da177e4 LT	41
1da177e4 LT	42	/* Insmod parameters */
f4b50261	43	I2C_CLIENT_INSMOD_1(lm77);
1da177e4 LT	44
	45	/* The LM77 registers */
	46	#define LM77_REG_TEMP 0x00
	47	#define LM77_REG_CONF 0x01
	48	#define LM77_REG_TEMP_HYST 0x02
	49	#define LM77_REG_TEMP_CRIT 0x03
	50	#define LM77_REG_TEMP_MIN 0x04
	51	#define LM77_REG_TEMP_MAX 0x05
	52
	53	/* Each client has this additional data */
	54	struct lm77_data {
1beeffe4	55	struct device *hwmon_dev;
9a61bf63	56	struct mutex update_lock;
1da177e4 LT	57	char valid;
	58	unsigned long last_updated; /* In jiffies */
	59	int temp_input; /* Temperatures */
	60	int temp_crit;
	61	int temp_min;
	62	int temp_max;
	63	int temp_hyst;
	64	u8 alarms;
	65	};
	66
a189dd62 JD	67	static int lm77_probe(struct i2c_client *client,
	68	const struct i2c_device_id *id);
	69	static int lm77_detect(struct i2c_client *client, int kind,
	70	struct i2c_board_info *info);
1da177e4	71	static void lm77_init_client(struct i2c_client *client);
a189dd62	72	static int lm77_remove(struct i2c_client *client);
1da177e4 LT	73	static u16 lm77_read_value(struct i2c_client *client, u8 reg);
	74	static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
	75
	76	static struct lm77_data lm77_update_device(struct device dev);
	77
	78
a189dd62 JD	79	static const struct i2c_device_id lm77_id[] = {
	80	{ "lm77", lm77 },
	81	{ }
	82	};
	83	MODULE_DEVICE_TABLE(i2c, lm77_id);
	84
1da177e4 LT	85	/* This is the driver that will be inserted */
1da177e4 LT	86	static struct i2c_driver lm77_driver = {
a189dd62	87	.class = I2C_CLASS_HWMON,
cdaf7934	88	.driver = {
cdaf7934 LR	89	.name = "lm77",
cdaf7934 LR	90	},
a189dd62 JD	91	.probe = lm77_probe,
	92	.remove = lm77_remove,
	93	.id_table = lm77_id,
	94	.detect = lm77_detect,
	95	.address_data = &addr_data,
1da177e4 LT	96	};
	97
	98	/* straight from the datasheet */
	99	#define LM77_TEMP_MIN (-55000)
	100	#define LM77_TEMP_MAX 125000
	101
	102	/* In the temperature registers, the low 3 bits are not part of the
	103	temperature values; they are the status bits. */
413b6451	104	static inline s16 LM77_TEMP_TO_REG(int temp)
1da177e4 LT	105	{
1da177e4 LT	106	int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
413b6451	107	return (ntemp / 500) * 8;
1da177e4 LT	108	}
1da177e4 LT	109
413b6451	110	static inline int LM77_TEMP_FROM_REG(s16 reg)
1da177e4	111	{
413b6451	112	return (reg / 8) * 500;
1da177e4 LT	113	}
	114
	115	/* sysfs stuff */
	116
	117	/* read routines for temperature limits */
	118	#define show(value) \
8627f9ba	119	static ssize_t show_##value(struct device dev, struct device_attribute attr, char *buf) \
1da177e4 LT	120	{ \
	121	struct lm77_data *data = lm77_update_device(dev); \
	122	return sprintf(buf, "%d\n", data->value); \
	123	}
	124
	125	show(temp_input);
	126	show(temp_crit);
	127	show(temp_min);
	128	show(temp_max);
1da177e4 LT	129
1da177e4 LT	130	/* read routines for hysteresis values */
8627f9ba	131	static ssize_t show_temp_crit_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	132	{
	133	struct lm77_data *data = lm77_update_device(dev);
	134	return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
	135	}
8627f9ba	136	static ssize_t show_temp_min_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	137	{
	138	struct lm77_data *data = lm77_update_device(dev);
	139	return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
	140	}
8627f9ba	141	static ssize_t show_temp_max_hyst(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	142	{
	143	struct lm77_data *data = lm77_update_device(dev);
	144	return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
	145	}
	146
	147	/* write routines */
	148	#define set(value, reg) \
8627f9ba	149	static ssize_t set_##value(struct device dev, struct device_attribute attr, const char *buf, size_t count) \
1da177e4 LT	150	{ \
	151	struct i2c_client *client = to_i2c_client(dev); \
	152	struct lm77_data *data = i2c_get_clientdata(client); \
5bfedac0	153	long val = simple_strtol(buf, NULL, 10); \
1da177e4	154	\
9a61bf63	155	mutex_lock(&data->update_lock); \
1da177e4 LT	156	data->value = val; \
1da177e4 LT	157	lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
9a61bf63	158	mutex_unlock(&data->update_lock); \
1da177e4 LT	159	return count; \
	160	}
	161
	162	set(temp_min, LM77_REG_TEMP_MIN);
	163	set(temp_max, LM77_REG_TEMP_MAX);
	164
	165	/* hysteresis is stored as a relative value on the chip, so it has to be
	166	converted first */
8627f9ba	167	static ssize_t set_temp_crit_hyst(struct device dev, struct device_attribute attr, const char *buf, size_t count)
1da177e4 LT	168	{
	169	struct i2c_client *client = to_i2c_client(dev);
	170	struct lm77_data *data = i2c_get_clientdata(client);
	171	unsigned long val = simple_strtoul(buf, NULL, 10);
	172
9a61bf63	173	mutex_lock(&data->update_lock);
1da177e4 LT	174	data->temp_hyst = data->temp_crit - val;
	175	lm77_write_value(client, LM77_REG_TEMP_HYST,
	176	LM77_TEMP_TO_REG(data->temp_hyst));
9a61bf63	177	mutex_unlock(&data->update_lock);
1da177e4 LT	178	return count;
	179	}
	180
	181	/* preserve hysteresis when setting T_crit */
8627f9ba	182	static ssize_t set_temp_crit(struct device dev, struct device_attribute attr, const char *buf, size_t count)
1da177e4 LT	183	{
	184	struct i2c_client *client = to_i2c_client(dev);
	185	struct lm77_data *data = i2c_get_clientdata(client);
	186	long val = simple_strtoul(buf, NULL, 10);
	187	int oldcrithyst;
	188
9a61bf63	189	mutex_lock(&data->update_lock);
1da177e4 LT	190	oldcrithyst = data->temp_crit - data->temp_hyst;
	191	data->temp_crit = val;
	192	data->temp_hyst = data->temp_crit - oldcrithyst;
	193	lm77_write_value(client, LM77_REG_TEMP_CRIT,
	194	LM77_TEMP_TO_REG(data->temp_crit));
	195	lm77_write_value(client, LM77_REG_TEMP_HYST,
	196	LM77_TEMP_TO_REG(data->temp_hyst));
9a61bf63	197	mutex_unlock(&data->update_lock);
1da177e4 LT	198	return count;
	199	}
	200
1f52af0f JD	201	static ssize_t show_alarm(struct device dev, struct device_attribute attr,
	202	char *buf)
	203	{
	204	int bitnr = to_sensor_dev_attr(attr)->index;
	205	struct lm77_data *data = lm77_update_device(dev);
	206	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
	207	}
	208
1da177e4 LT	209	static DEVICE_ATTR(temp1_input, S_IRUGO,
	210	show_temp_input, NULL);
	211	static DEVICE_ATTR(temp1_crit, S_IWUSR \| S_IRUGO,
	212	show_temp_crit, set_temp_crit);
	213	static DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO,
	214	show_temp_min, set_temp_min);
	215	static DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
	216	show_temp_max, set_temp_max);
	217
	218	static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR \| S_IRUGO,
	219	show_temp_crit_hyst, set_temp_crit_hyst);
	220	static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
	221	show_temp_min_hyst, NULL);
	222	static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
	223	show_temp_max_hyst, NULL);
	224
1f52af0f JD	225	static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
	226	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
	227	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
1da177e4	228
0501a381 MH	229	static struct attribute *lm77_attributes[] = {
	230	&dev_attr_temp1_input.attr,
	231	&dev_attr_temp1_crit.attr,
	232	&dev_attr_temp1_min.attr,
	233	&dev_attr_temp1_max.attr,
	234	&dev_attr_temp1_crit_hyst.attr,
	235	&dev_attr_temp1_min_hyst.attr,
	236	&dev_attr_temp1_max_hyst.attr,
1f52af0f JD	237	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	238	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	239	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
0501a381 MH	240	NULL
	241	};
	242
	243	static const struct attribute_group lm77_group = {
	244	.attrs = lm77_attributes,
	245	};
	246
a189dd62 JD	247	/* Return 0 if detection is successful, -ENODEV otherwise */
	248	static int lm77_detect(struct i2c_client *new_client, int kind,
	249	struct i2c_board_info *info)
1da177e4	250	{
a189dd62	251	struct i2c_adapter *adapter = new_client->adapter;
1da177e4 LT	252
	253	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
	254	I2C_FUNC_SMBUS_WORD_DATA))
a189dd62	255	return -ENODEV;
1da177e4 LT	256
	257	/* Here comes the remaining detection. Since the LM77 has no
	258	register dedicated to identification, we have to rely on the
	259	following tricks:
	260
	261	1. the high 4 bits represent the sign and thus they should
	262	always be the same
	263	2. the high 3 bits are unused in the configuration register
	264	3. addresses 0x06 and 0x07 return the last read value
	265	4. registers cycling over 8-address boundaries
	266
	267	Word-sized registers are high-byte first. */
	268	if (kind < 0) {
	269	int i, cur, conf, hyst, crit, min, max;
	270
	271	/* addresses cycling */
	272	cur = i2c_smbus_read_word_data(new_client, 0);
	273	conf = i2c_smbus_read_byte_data(new_client, 1);
	274	hyst = i2c_smbus_read_word_data(new_client, 2);
	275	crit = i2c_smbus_read_word_data(new_client, 3);
	276	min = i2c_smbus_read_word_data(new_client, 4);
	277	max = i2c_smbus_read_word_data(new_client, 5);
	278	for (i = 8; i <= 0xff; i += 8)
	279	if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
	280	\|\| i2c_smbus_read_word_data(new_client, i + 2) != hyst
	281	\|\| i2c_smbus_read_word_data(new_client, i + 3) != crit
	282	\|\| i2c_smbus_read_word_data(new_client, i + 4) != min
	283	\|\| i2c_smbus_read_word_data(new_client, i + 5) != max)
a189dd62	284	return -ENODEV;
1da177e4 LT	285
	286	/* sign bits */
	287	if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
	288	\|\| ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
	289	\|\| ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
	290	\|\| ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
	291	\|\| ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
a189dd62	292	return -ENODEV;
1da177e4 LT	293
	294	/* unused bits */
	295	if (conf & 0xe0)
a189dd62	296	return -ENODEV;
1da177e4 LT	297
	298	/* 0x06 and 0x07 return the last read value */
	299	cur = i2c_smbus_read_word_data(new_client, 0);
	300	if (i2c_smbus_read_word_data(new_client, 6) != cur
	301	\|\| i2c_smbus_read_word_data(new_client, 7) != cur)
a189dd62	302	return -ENODEV;
1da177e4 LT	303	hyst = i2c_smbus_read_word_data(new_client, 2);
	304	if (i2c_smbus_read_word_data(new_client, 6) != hyst
	305	\|\| i2c_smbus_read_word_data(new_client, 7) != hyst)
a189dd62	306	return -ENODEV;
1da177e4 LT	307	min = i2c_smbus_read_word_data(new_client, 4);
	308	if (i2c_smbus_read_word_data(new_client, 6) != min
	309	\|\| i2c_smbus_read_word_data(new_client, 7) != min)
a189dd62	310	return -ENODEV;
1da177e4 LT	311
	312	}
	313
a189dd62	314	strlcpy(info->type, "lm77", I2C_NAME_SIZE);
1da177e4	315
a189dd62 JD	316	return 0;
	317	}
	318
	319	static int lm77_probe(struct i2c_client *new_client,
	320	const struct i2c_device_id *id)
	321	{
	322	struct lm77_data *data;
	323	int err;
	324
	325	data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL);
	326	if (!data) {
	327	err = -ENOMEM;
	328	goto exit;
1da177e4 LT	329	}
1da177e4 LT	330
a189dd62	331	i2c_set_clientdata(new_client, data);
1da177e4	332	data->valid = 0;
9a61bf63	333	mutex_init(&data->update_lock);
1da177e4	334
1da177e4 LT	335	/* Initialize the LM77 chip */
	336	lm77_init_client(new_client);
	337
	338	/* Register sysfs hooks */
0501a381	339	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group)))
a189dd62	340	goto exit_free;
0501a381	341
1beeffe4 TJ	342	data->hwmon_dev = hwmon_device_register(&new_client->dev);
	343	if (IS_ERR(data->hwmon_dev)) {
	344	err = PTR_ERR(data->hwmon_dev);
0501a381	345	goto exit_remove;
943b0830 MH	346	}
943b0830 MH	347
1da177e4 LT	348	return 0;
1da177e4 LT	349
0501a381 MH	350	exit_remove:
0501a381 MH	351	sysfs_remove_group(&new_client->dev.kobj, &lm77_group);
1da177e4 LT	352	exit_free:
	353	kfree(data);
	354	exit:
	355	return err;
	356	}
	357
a189dd62	358	static int lm77_remove(struct i2c_client *client)
1da177e4	359	{
943b0830	360	struct lm77_data *data = i2c_get_clientdata(client);
1beeffe4	361	hwmon_device_unregister(data->hwmon_dev);
0501a381	362	sysfs_remove_group(&client->dev.kobj, &lm77_group);
943b0830	363	kfree(data);
1da177e4 LT	364	return 0;
	365	}
	366
	367	/* All registers are word-sized, except for the configuration register.
	368	The LM77 uses the high-byte first convention. */
	369	static u16 lm77_read_value(struct i2c_client *client, u8 reg)
	370	{
	371	if (reg == LM77_REG_CONF)
	372	return i2c_smbus_read_byte_data(client, reg);
	373	else
	374	return swab16(i2c_smbus_read_word_data(client, reg));
	375	}
	376
	377	static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
	378	{
	379	if (reg == LM77_REG_CONF)
	380	return i2c_smbus_write_byte_data(client, reg, value);
	381	else
	382	return i2c_smbus_write_word_data(client, reg, swab16(value));
	383	}
	384
	385	static void lm77_init_client(struct i2c_client *client)
	386	{
	387	/* Initialize the LM77 chip - turn off shutdown mode */
	388	int conf = lm77_read_value(client, LM77_REG_CONF);
	389	if (conf & 1)
	390	lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
	391	}
	392
	393	static struct lm77_data lm77_update_device(struct device dev)
	394	{
	395	struct i2c_client *client = to_i2c_client(dev);
	396	struct lm77_data *data = i2c_get_clientdata(client);
	397
9a61bf63	398	mutex_lock(&data->update_lock);
1da177e4 LT	399
	400	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	401	\|\| !data->valid) {
	402	dev_dbg(&client->dev, "Starting lm77 update\n");
	403	data->temp_input =
	404	LM77_TEMP_FROM_REG(lm77_read_value(client,
	405	LM77_REG_TEMP));
	406	data->temp_hyst =
	407	LM77_TEMP_FROM_REG(lm77_read_value(client,
	408	LM77_REG_TEMP_HYST));
	409	data->temp_crit =
	410	LM77_TEMP_FROM_REG(lm77_read_value(client,
	411	LM77_REG_TEMP_CRIT));
	412	data->temp_min =
	413	LM77_TEMP_FROM_REG(lm77_read_value(client,
	414	LM77_REG_TEMP_MIN));
	415	data->temp_max =
	416	LM77_TEMP_FROM_REG(lm77_read_value(client,
	417	LM77_REG_TEMP_MAX));
	418	data->alarms =
	419	lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
	420	data->last_updated = jiffies;
	421	data->valid = 1;
	422	}
	423
9a61bf63	424	mutex_unlock(&data->update_lock);
1da177e4 LT	425
	426	return data;
	427	}
	428
	429	static int __init sensors_lm77_init(void)
	430	{
	431	return i2c_add_driver(&lm77_driver);
	432	}
	433
	434	static void __exit sensors_lm77_exit(void)
	435	{
	436	i2c_del_driver(&lm77_driver);
	437	}
	438
	439	MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
	440	MODULE_DESCRIPTION("LM77 driver");
	441	MODULE_LICENSE("GPL");
	442
	443	module_init(sensors_lm77_init);
	444	module_exit(sensors_lm77_exit);