[mirror_ubuntu-hirsute-kernel.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.
 */

#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 };

/* 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;
};

/* 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 = clamp_val(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
	return (ntemp / 500) * 8;
}

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

/*
 * 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 i2c_smbus_read_word_swapped(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_swapped(client, reg, value);
}

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;
}

/* 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;							\
	int err = kstrtol(buf, 10, &val);				\
	if (err)							\
		return err;						\
									\
	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;
	int err;

	err = kstrtoul(buf, 10, &val);
	if (err)
		return err;

	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;
}

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);
	unsigned long val;
	int err;

	err = kstrtoul(buf, 10, &val);
	if (err)
		return err;

	mutex_lock(&data->update_lock);
	data->temp_crit = val;
	lm77_write_value(client, LM77_REG_TEMP_CRIT,
			 LM77_TEMP_TO_REG(data->temp_crit));
	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 *client, struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = client->adapter;
	int i, cur, conf, hyst, crit, min, max;

	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.
	 */

	/* addresses cycling */
	cur = i2c_smbus_read_word_data(client, 0);
	conf = i2c_smbus_read_byte_data(client, 1);
	hyst = i2c_smbus_read_word_data(client, 2);
	crit = i2c_smbus_read_word_data(client, 3);
	min = i2c_smbus_read_word_data(client, 4);
	max = i2c_smbus_read_word_data(client, 5);
	for (i = 8; i <= 0xff; i += 8) {
		if (i2c_smbus_read_byte_data(client, i + 1) != conf
		 || i2c_smbus_read_word_data(client, i + 2) != hyst
		 || i2c_smbus_read_word_data(client, i + 3) != crit
		 || i2c_smbus_read_word_data(client, i + 4) != min
		 || i2c_smbus_read_word_data(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(client, 0);
	if (i2c_smbus_read_word_data(client, 6) != cur
	 || i2c_smbus_read_word_data(client, 7) != cur)
		return -ENODEV;
	hyst = i2c_smbus_read_word_data(client, 2);
	if (i2c_smbus_read_word_data(client, 6) != hyst
	 || i2c_smbus_read_word_data(client, 7) != hyst)
		return -ENODEV;
	min = i2c_smbus_read_word_data(client, 4);
	if (i2c_smbus_read_word_data(client, 6) != min
	 || i2c_smbus_read_word_data(client, 7) != min)
		return -ENODEV;

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

	return 0;
}

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 int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct lm77_data *data;
	int err;

	data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

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

	/* Initialize the LM77 chip */
	lm77_init_client(client);

	/* Register sysfs hooks */
	err = sysfs_create_group(&dev->kobj, &lm77_group);
	if (err)
		return err;

	data->hwmon_dev = hwmon_device_register(dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		goto exit_remove;
	}

	return 0;

exit_remove:
	sysfs_remove_group(&dev->kobj, &lm77_group);
	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);
	return 0;
}

static const struct i2c_device_id lm77_id[] = {
	{ "lm77", 0 },
	{ }
};
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_list	= normal_i2c,
};

module_i2c_driver(lm77_driver);

MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
MODULE_DESCRIPTION("LM77 driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4	1	/*
02fe2fd9 GR	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.
02fe2fd9	22	*/
1da177e4	23
1da177e4 LT	24	#include <linux/module.h>
	25	#include <linux/init.h>
	26	#include <linux/slab.h>
	27	#include <linux/jiffies.h>
	28	#include <linux/i2c.h>
943b0830	29	#include <linux/hwmon.h>
1f52af0f	30	#include <linux/hwmon-sysfs.h>
943b0830	31	#include <linux/err.h>
9a61bf63	32	#include <linux/mutex.h>
1da177e4 LT	33
1da177e4 LT	34	/* Addresses to scan */
25e9c86d MH	35	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
25e9c86d MH	36	I2C_CLIENT_END };
1da177e4	37
1da177e4 LT	38	/* The LM77 registers */
	39	#define LM77_REG_TEMP 0x00
	40	#define LM77_REG_CONF 0x01
	41	#define LM77_REG_TEMP_HYST 0x02
	42	#define LM77_REG_TEMP_CRIT 0x03
	43	#define LM77_REG_TEMP_MIN 0x04
	44	#define LM77_REG_TEMP_MAX 0x05
	45
	46	/* Each client has this additional data */
	47	struct lm77_data {
02fe2fd9	48	struct device *hwmon_dev;
9a61bf63	49	struct mutex update_lock;
1da177e4 LT	50	char valid;
	51	unsigned long last_updated; /* In jiffies */
	52	int temp_input; /* Temperatures */
	53	int temp_crit;
	54	int temp_min;
	55	int temp_max;
	56	int temp_hyst;
	57	u8 alarms;
	58	};
	59
1da177e4 LT	60	/* straight from the datasheet */
	61	#define LM77_TEMP_MIN (-55000)
	62	#define LM77_TEMP_MAX 125000
	63
02fe2fd9 GR	64	/*
	65	* In the temperature registers, the low 3 bits are not part of the
	66	* temperature values; they are the status bits.
	67	*/
413b6451	68	static inline s16 LM77_TEMP_TO_REG(int temp)
1da177e4	69	{
2a844c14	70	int ntemp = clamp_val(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
413b6451	71	return (ntemp / 500) * 8;
1da177e4 LT	72	}
1da177e4 LT	73
413b6451	74	static inline int LM77_TEMP_FROM_REG(s16 reg)
1da177e4	75	{
413b6451	76	return (reg / 8) * 500;
1da177e4 LT	77	}
1da177e4 LT	78
9f9edcd4 GR	79	/*
	80	* All registers are word-sized, except for the configuration register.
	81	* The LM77 uses the high-byte first convention.
	82	*/
	83	static u16 lm77_read_value(struct i2c_client *client, u8 reg)
	84	{
	85	if (reg == LM77_REG_CONF)
	86	return i2c_smbus_read_byte_data(client, reg);
	87	else
	88	return i2c_smbus_read_word_swapped(client, reg);
	89	}
	90
	91	static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
	92	{
	93	if (reg == LM77_REG_CONF)
	94	return i2c_smbus_write_byte_data(client, reg, value);
	95	else
	96	return i2c_smbus_write_word_swapped(client, reg, value);
	97	}
	98
	99	static struct lm77_data lm77_update_device(struct device dev)
	100	{
	101	struct i2c_client *client = to_i2c_client(dev);
	102	struct lm77_data *data = i2c_get_clientdata(client);
	103
	104	mutex_lock(&data->update_lock);
	105
	106	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	107	\|\| !data->valid) {
	108	dev_dbg(&client->dev, "Starting lm77 update\n");
	109	data->temp_input =
	110	LM77_TEMP_FROM_REG(lm77_read_value(client,
	111	LM77_REG_TEMP));
	112	data->temp_hyst =
	113	LM77_TEMP_FROM_REG(lm77_read_value(client,
	114	LM77_REG_TEMP_HYST));
	115	data->temp_crit =
	116	LM77_TEMP_FROM_REG(lm77_read_value(client,
	117	LM77_REG_TEMP_CRIT));
	118	data->temp_min =
	119	LM77_TEMP_FROM_REG(lm77_read_value(client,
	120	LM77_REG_TEMP_MIN));
	121	data->temp_max =
	122	LM77_TEMP_FROM_REG(lm77_read_value(client,
	123	LM77_REG_TEMP_MAX));
	124	data->alarms =
	125	lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
	126	data->last_updated = jiffies;
	127	data->valid = 1;
	128	}
	129
	130	mutex_unlock(&data->update_lock);
	131
	132	return data;
	133	}
	134
1da177e4 LT	135	/* sysfs stuff */
	136
	137	/* read routines for temperature limits */
	138	#define show(value) \
02fe2fd9 GR	139	static ssize_t show_##value(struct device *dev, \
	140	struct device_attribute *attr, \
	141	char *buf) \
1da177e4 LT	142	{ \
	143	struct lm77_data *data = lm77_update_device(dev); \
	144	return sprintf(buf, "%d\n", data->value); \
	145	}
	146
	147	show(temp_input);
	148	show(temp_crit);
	149	show(temp_min);
	150	show(temp_max);
1da177e4 LT	151
1da177e4 LT	152	/* read routines for hysteresis values */
02fe2fd9 GR	153	static ssize_t show_temp_crit_hyst(struct device *dev,
02fe2fd9 GR	154	struct device_attribute attr, char buf)
1da177e4 LT	155	{
	156	struct lm77_data *data = lm77_update_device(dev);
	157	return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
	158	}
02fe2fd9 GR	159	static ssize_t show_temp_min_hyst(struct device *dev,
02fe2fd9 GR	160	struct device_attribute attr, char buf)
1da177e4 LT	161	{
	162	struct lm77_data *data = lm77_update_device(dev);
	163	return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
	164	}
02fe2fd9 GR	165	static ssize_t show_temp_max_hyst(struct device *dev,
02fe2fd9 GR	166	struct device_attribute attr, char buf)
1da177e4 LT	167	{
	168	struct lm77_data *data = lm77_update_device(dev);
	169	return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
	170	}
	171
	172	/* write routines */
	173	#define set(value, reg) \
02fe2fd9 GR	174	static ssize_t set_##value(struct device dev, struct device_attribute attr, \
	175	const char *buf, size_t count) \
	176	{ \
	177	struct i2c_client *client = to_i2c_client(dev); \
	178	struct lm77_data *data = i2c_get_clientdata(client); \
	179	long val; \
	180	int err = kstrtol(buf, 10, &val); \
	181	if (err) \
	182	return err; \
	183	\
	184	mutex_lock(&data->update_lock); \
	185	data->value = val; \
	186	lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
	187	mutex_unlock(&data->update_lock); \
	188	return count; \
1da177e4 LT	189	}
	190
	191	set(temp_min, LM77_REG_TEMP_MIN);
	192	set(temp_max, LM77_REG_TEMP_MAX);
	193
02fe2fd9 GR	194	/*
	195	* hysteresis is stored as a relative value on the chip, so it has to be
	196	* converted first
	197	*/
	198	static ssize_t set_temp_crit_hyst(struct device *dev,
	199	struct device_attribute *attr,
	200	const char *buf, size_t count)
1da177e4 LT	201	{
	202	struct i2c_client *client = to_i2c_client(dev);
	203	struct lm77_data *data = i2c_get_clientdata(client);
02fe2fd9 GR	204	unsigned long val;
	205	int err;
	206
	207	err = kstrtoul(buf, 10, &val);
	208	if (err)
	209	return err;
1da177e4	210
9a61bf63	211	mutex_lock(&data->update_lock);
1da177e4 LT	212	data->temp_hyst = data->temp_crit - val;
	213	lm77_write_value(client, LM77_REG_TEMP_HYST,
	214	LM77_TEMP_TO_REG(data->temp_hyst));
9a61bf63	215	mutex_unlock(&data->update_lock);
1da177e4 LT	216	return count;
	217	}
	218
02fe2fd9 GR	219	static ssize_t set_temp_crit(struct device dev, struct device_attribute attr,
02fe2fd9 GR	220	const char *buf, size_t count)
1da177e4 LT	221	{
	222	struct i2c_client *client = to_i2c_client(dev);
	223	struct lm77_data *data = i2c_get_clientdata(client);
02fe2fd9 GR	224	unsigned long val;
	225	int err;
	226
	227	err = kstrtoul(buf, 10, &val);
	228	if (err)
	229	return err;
	230
9a61bf63	231	mutex_lock(&data->update_lock);
1da177e4	232	data->temp_crit = val;
1da177e4 LT	233	lm77_write_value(client, LM77_REG_TEMP_CRIT,
1da177e4 LT	234	LM77_TEMP_TO_REG(data->temp_crit));
9a61bf63	235	mutex_unlock(&data->update_lock);
1da177e4 LT	236	return count;
	237	}
	238
1f52af0f JD	239	static ssize_t show_alarm(struct device dev, struct device_attribute attr,
	240	char *buf)
	241	{
	242	int bitnr = to_sensor_dev_attr(attr)->index;
	243	struct lm77_data *data = lm77_update_device(dev);
	244	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
	245	}
	246
1da177e4 LT	247	static DEVICE_ATTR(temp1_input, S_IRUGO,
	248	show_temp_input, NULL);
	249	static DEVICE_ATTR(temp1_crit, S_IWUSR \| S_IRUGO,
	250	show_temp_crit, set_temp_crit);
	251	static DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO,
	252	show_temp_min, set_temp_min);
	253	static DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
	254	show_temp_max, set_temp_max);
	255
	256	static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR \| S_IRUGO,
	257	show_temp_crit_hyst, set_temp_crit_hyst);
	258	static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
	259	show_temp_min_hyst, NULL);
	260	static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
	261	show_temp_max_hyst, NULL);
	262
1f52af0f JD	263	static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
	264	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
	265	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
1da177e4	266
0501a381 MH	267	static struct attribute *lm77_attributes[] = {
	268	&dev_attr_temp1_input.attr,
	269	&dev_attr_temp1_crit.attr,
	270	&dev_attr_temp1_min.attr,
	271	&dev_attr_temp1_max.attr,
	272	&dev_attr_temp1_crit_hyst.attr,
	273	&dev_attr_temp1_min_hyst.attr,
	274	&dev_attr_temp1_max_hyst.attr,
1f52af0f JD	275	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	276	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	277	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
0501a381 MH	278	NULL
	279	};
	280
	281	static const struct attribute_group lm77_group = {
	282	.attrs = lm77_attributes,
	283	};
	284
a189dd62	285	/* Return 0 if detection is successful, -ENODEV otherwise */
efd2d117	286	static int lm77_detect(struct i2c_client client, struct i2c_board_info info)
1da177e4	287	{
efd2d117	288	struct i2c_adapter *adapter = client->adapter;
747d9bed	289	int i, cur, conf, hyst, crit, min, max;
1da177e4 LT	290
	291	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
	292	I2C_FUNC_SMBUS_WORD_DATA))
a189dd62	293	return -ENODEV;
1da177e4	294
02fe2fd9 GR	295	/*
	296	* Here comes the remaining detection. Since the LM77 has no
	297	* register dedicated to identification, we have to rely on the
	298	* following tricks:
	299	*
	300	* 1. the high 4 bits represent the sign and thus they should
	301	* always be the same
	302	* 2. the high 3 bits are unused in the configuration register
	303	* 3. addresses 0x06 and 0x07 return the last read value
	304	* 4. registers cycling over 8-address boundaries
	305	*
	306	* Word-sized registers are high-byte first.
	307	*/
1da177e4	308
747d9bed	309	/* addresses cycling */
efd2d117 GR	310	cur = i2c_smbus_read_word_data(client, 0);
	311	conf = i2c_smbus_read_byte_data(client, 1);
	312	hyst = i2c_smbus_read_word_data(client, 2);
	313	crit = i2c_smbus_read_word_data(client, 3);
	314	min = i2c_smbus_read_word_data(client, 4);
	315	max = i2c_smbus_read_word_data(client, 5);
747d9bed	316	for (i = 8; i <= 0xff; i += 8) {
efd2d117 GR	317	if (i2c_smbus_read_byte_data(client, i + 1) != conf
	318	\|\| i2c_smbus_read_word_data(client, i + 2) != hyst
	319	\|\| i2c_smbus_read_word_data(client, i + 3) != crit
	320	\|\| i2c_smbus_read_word_data(client, i + 4) != min
	321	\|\| i2c_smbus_read_word_data(client, i + 5) != max)
a189dd62	322	return -ENODEV;
747d9bed	323	}
1da177e4	324
747d9bed JD	325	/* sign bits */
	326	if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
	327	\|\| ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
	328	\|\| ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
	329	\|\| ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
	330	\|\| ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
	331	return -ENODEV;
1da177e4	332
747d9bed JD	333	/* unused bits */
	334	if (conf & 0xe0)
	335	return -ENODEV;
	336
	337	/* 0x06 and 0x07 return the last read value */
efd2d117 GR	338	cur = i2c_smbus_read_word_data(client, 0);
	339	if (i2c_smbus_read_word_data(client, 6) != cur
	340	\|\| i2c_smbus_read_word_data(client, 7) != cur)
747d9bed	341	return -ENODEV;
efd2d117 GR	342	hyst = i2c_smbus_read_word_data(client, 2);
	343	if (i2c_smbus_read_word_data(client, 6) != hyst
	344	\|\| i2c_smbus_read_word_data(client, 7) != hyst)
747d9bed	345	return -ENODEV;
efd2d117 GR	346	min = i2c_smbus_read_word_data(client, 4);
	347	if (i2c_smbus_read_word_data(client, 6) != min
	348	\|\| i2c_smbus_read_word_data(client, 7) != min)
747d9bed	349	return -ENODEV;
1da177e4	350
a189dd62	351	strlcpy(info->type, "lm77", I2C_NAME_SIZE);
1da177e4	352
a189dd62 JD	353	return 0;
	354	}
	355
9f9edcd4 GR	356	static void lm77_init_client(struct i2c_client *client)
	357	{
	358	/* Initialize the LM77 chip - turn off shutdown mode */
	359	int conf = lm77_read_value(client, LM77_REG_CONF);
	360	if (conf & 1)
	361	lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
	362	}
	363
efd2d117	364	static int lm77_probe(struct i2c_client client, const struct i2c_device_id id)
a189dd62	365	{
efd2d117	366	struct device *dev = &client->dev;
a189dd62 JD	367	struct lm77_data *data;
	368	int err;
	369
52714c04 GR	370	data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL);
	371	if (!data)
	372	return -ENOMEM;
1da177e4	373
efd2d117	374	i2c_set_clientdata(client, data);
9a61bf63	375	mutex_init(&data->update_lock);
1da177e4	376
1da177e4	377	/* Initialize the LM77 chip */
efd2d117	378	lm77_init_client(client);
1da177e4 LT	379
1da177e4 LT	380	/* Register sysfs hooks */
efd2d117	381	err = sysfs_create_group(&dev->kobj, &lm77_group);
02fe2fd9	382	if (err)
52714c04	383	return err;
0501a381	384
efd2d117	385	data->hwmon_dev = hwmon_device_register(dev);
1beeffe4 TJ	386	if (IS_ERR(data->hwmon_dev)) {
1beeffe4 TJ	387	err = PTR_ERR(data->hwmon_dev);
0501a381	388	goto exit_remove;
943b0830 MH	389	}
943b0830 MH	390
1da177e4 LT	391	return 0;
1da177e4 LT	392
0501a381	393	exit_remove:
efd2d117	394	sysfs_remove_group(&dev->kobj, &lm77_group);
1da177e4 LT	395	return err;
	396	}
	397
a189dd62	398	static int lm77_remove(struct i2c_client *client)
1da177e4	399	{
943b0830	400	struct lm77_data *data = i2c_get_clientdata(client);
1beeffe4	401	hwmon_device_unregister(data->hwmon_dev);
0501a381	402	sysfs_remove_group(&client->dev.kobj, &lm77_group);
1da177e4 LT	403	return 0;
	404	}
	405
9f9edcd4 GR	406	static const struct i2c_device_id lm77_id[] = {
	407	{ "lm77", 0 },
	408	{ }
	409	};
	410	MODULE_DEVICE_TABLE(i2c, lm77_id);
1da177e4	411
9f9edcd4 GR	412	/* This is the driver that will be inserted */
	413	static struct i2c_driver lm77_driver = {
	414	.class = I2C_CLASS_HWMON,
	415	.driver = {
	416	.name = "lm77",
	417	},
	418	.probe = lm77_probe,
	419	.remove = lm77_remove,
	420	.id_table = lm77_id,
	421	.detect = lm77_detect,
	422	.address_list = normal_i2c,
	423	};
1da177e4	424
f0967eea	425	module_i2c_driver(lm77_driver);
1da177e4 LT	426
	427	MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
	428	MODULE_DESCRIPTION("LM77 driver");
	429	MODULE_LICENSE("GPL");