[deliverable/linux.git] / drivers / hwmon / lm75.c

/*
 * lm75.c - Part of lm_sensors, Linux kernel modules for hardware
 *	 monitoring
 * Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
 *
 * 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>
#include "lm75.h"


/*
 * This driver handles the LM75 and compatible digital temperature sensors.
 */

enum lm75_type {		/* keep sorted in alphabetical order */
	adt75,
	ds1775,
	ds75,
	lm75,
	lm75a,
	max6625,
	max6626,
	mcp980x,
	stds75,
	tcn75,
	tmp100,
	tmp101,
	tmp105,
	tmp175,
	tmp275,
	tmp75,
};

/* Addresses scanned */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
					0x4d, 0x4e, 0x4f, I2C_CLIENT_END };


/* The LM75 registers */
#define LM75_REG_CONF		0x01
static const u8 LM75_REG_TEMP[3] = {
	0x00,		/* input */
	0x03,		/* max */
	0x02,		/* hyst */
};

/* Each client has this additional data */
struct lm75_data {
	struct device		*hwmon_dev;
	struct mutex		update_lock;
	u8			orig_conf;
	char			valid;		/* !=0 if registers are valid */
	unsigned long		last_updated;	/* In jiffies */
	u16			temp[3];	/* Register values,
						   0 = input
						   1 = max
						   2 = hyst */
};

static int lm75_read_value(struct i2c_client *client, u8 reg);
static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
static struct lm75_data *lm75_update_device(struct device *dev);


/*-----------------------------------------------------------------------*/

/* sysfs attributes for hwmon */

static ssize_t show_temp(struct device *dev, struct device_attribute *da,
			 char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct lm75_data *data = lm75_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n",
		       LM75_TEMP_FROM_REG(data->temp[attr->index]));
}

static ssize_t set_temp(struct device *dev, struct device_attribute *da,
			const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct i2c_client *client = to_i2c_client(dev);
	struct lm75_data *data = i2c_get_clientdata(client);
	int nr = attr->index;
	long temp;
	int error;

	error = kstrtol(buf, 10, &temp);
	if (error)
		return error;

	mutex_lock(&data->update_lock);
	data->temp[nr] = LM75_TEMP_TO_REG(temp);
	lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}

static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
			show_temp, set_temp, 1);
static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
			show_temp, set_temp, 2);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);

static struct attribute *lm75_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,

	NULL
};

static const struct attribute_group lm75_group = {
	.attrs = lm75_attributes,
};

/*-----------------------------------------------------------------------*/

/* device probe and removal */

static int
lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	struct lm75_data *data;
	int status;
	u8 set_mask, clr_mask;
	int new;

	if (!i2c_check_functionality(client->adapter,
			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
		return -EIO;

	data = devm_kzalloc(&client->dev, sizeof(struct lm75_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

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

	/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
	 * Then tweak to be more precise when appropriate.
	 */
	set_mask = 0;
	clr_mask = (1 << 0)			/* continuous conversions */
		| (1 << 6) | (1 << 5);		/* 9-bit mode */

	/* configure as specified */
	status = lm75_read_value(client, LM75_REG_CONF);
	if (status < 0) {
		dev_dbg(&client->dev, "Can't read config? %d\n", status);
		return status;
	}
	data->orig_conf = status;
	new = status & ~clr_mask;
	new |= set_mask;
	if (status != new)
		lm75_write_value(client, LM75_REG_CONF, new);
	dev_dbg(&client->dev, "Config %02x\n", new);

	/* Register sysfs hooks */
	status = sysfs_create_group(&client->dev.kobj, &lm75_group);
	if (status)
		return status;

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

	dev_info(&client->dev, "%s: sensor '%s'\n",
		 dev_name(data->hwmon_dev), client->name);

	return 0;

exit_remove:
	sysfs_remove_group(&client->dev.kobj, &lm75_group);
	return status;
}

static int lm75_remove(struct i2c_client *client)
{
	struct lm75_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &lm75_group);
	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
	return 0;
}

static const struct i2c_device_id lm75_ids[] = {
	{ "adt75", adt75, },
	{ "ds1775", ds1775, },
	{ "ds75", ds75, },
	{ "lm75", lm75, },
	{ "lm75a", lm75a, },
	{ "max6625", max6625, },
	{ "max6626", max6626, },
	{ "mcp980x", mcp980x, },
	{ "stds75", stds75, },
	{ "tcn75", tcn75, },
	{ "tmp100", tmp100, },
	{ "tmp101", tmp101, },
	{ "tmp105", tmp105, },
	{ "tmp175", tmp175, },
	{ "tmp275", tmp275, },
	{ "tmp75", tmp75, },
	{ /* LIST END */ }
};
MODULE_DEVICE_TABLE(i2c, lm75_ids);

#define LM75A_ID 0xA1

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm75_detect(struct i2c_client *new_client,
		       struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = new_client->adapter;
	int i;
	int conf, hyst, os;
	bool is_lm75a = 0;

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

	/*
	 * Now, we do the remaining detection. There is no identification-
	 * dedicated register so we have to rely on several tricks:
	 * unused bits, registers cycling over 8-address boundaries,
	 * addresses 0x04-0x07 returning the last read value.
	 * The cycling+unused addresses combination is not tested,
	 * since it would significantly slow the detection down and would
	 * hardly add any value.
	 *
	 * The National Semiconductor LM75A is different than earlier
	 * LM75s.  It has an ID byte of 0xaX (where X is the chip
	 * revision, with 1 being the only revision in existence) in
	 * register 7, and unused registers return 0xff rather than the
	 * last read value.
	 *
	 * Note that this function only detects the original National
	 * Semiconductor LM75 and the LM75A. Clones from other vendors
	 * aren't detected, on purpose, because they are typically never
	 * found on PC hardware. They are found on embedded designs where
	 * they can be instantiated explicitly so detection is not needed.
	 * The absence of identification registers on all these clones
	 * would make their exhaustive detection very difficult and weak,
	 * and odds are that the driver would bind to unsupported devices.
	 */

	/* Unused bits */
	conf = i2c_smbus_read_byte_data(new_client, 1);
	if (conf & 0xe0)
		return -ENODEV;

	/* First check for LM75A */
	if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
		/* LM75A returns 0xff on unused registers so
		   just to be sure we check for that too. */
		if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
		 || i2c_smbus_read_byte_data(new_client, 5) != 0xff
		 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
			return -ENODEV;
		is_lm75a = 1;
		hyst = i2c_smbus_read_byte_data(new_client, 2);
		os = i2c_smbus_read_byte_data(new_client, 3);
	} else { /* Traditional style LM75 detection */
		/* Unused addresses */
		hyst = i2c_smbus_read_byte_data(new_client, 2);
		if (i2c_smbus_read_byte_data(new_client, 4) != hyst
		 || i2c_smbus_read_byte_data(new_client, 5) != hyst
		 || i2c_smbus_read_byte_data(new_client, 6) != hyst
		 || i2c_smbus_read_byte_data(new_client, 7) != hyst)
			return -ENODEV;
		os = i2c_smbus_read_byte_data(new_client, 3);
		if (i2c_smbus_read_byte_data(new_client, 4) != os
		 || i2c_smbus_read_byte_data(new_client, 5) != os
		 || i2c_smbus_read_byte_data(new_client, 6) != os
		 || i2c_smbus_read_byte_data(new_client, 7) != os)
			return -ENODEV;
	}

	/* Addresses cycling */
	for (i = 8; i <= 248; i += 40) {
		if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
		 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
		 || i2c_smbus_read_byte_data(new_client, i + 3) != os)
			return -ENODEV;
		if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
				!= LM75A_ID)
			return -ENODEV;
	}

	strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);

	return 0;
}

#ifdef CONFIG_PM
static int lm75_suspend(struct device *dev)
{
	int status;
	struct i2c_client *client = to_i2c_client(dev);
	status = lm75_read_value(client, LM75_REG_CONF);
	if (status < 0) {
		dev_dbg(&client->dev, "Can't read config? %d\n", status);
		return status;
	}
	status = status | LM75_SHUTDOWN;
	lm75_write_value(client, LM75_REG_CONF, status);
	return 0;
}

static int lm75_resume(struct device *dev)
{
	int status;
	struct i2c_client *client = to_i2c_client(dev);
	status = lm75_read_value(client, LM75_REG_CONF);
	if (status < 0) {
		dev_dbg(&client->dev, "Can't read config? %d\n", status);
		return status;
	}
	status = status & ~LM75_SHUTDOWN;
	lm75_write_value(client, LM75_REG_CONF, status);
	return 0;
}

static const struct dev_pm_ops lm75_dev_pm_ops = {
	.suspend	= lm75_suspend,
	.resume		= lm75_resume,
};
#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
#else
#define LM75_DEV_PM_OPS NULL
#endif /* CONFIG_PM */

static struct i2c_driver lm75_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "lm75",
		.pm	= LM75_DEV_PM_OPS,
	},
	.probe		= lm75_probe,
	.remove		= lm75_remove,
	.id_table	= lm75_ids,
	.detect		= lm75_detect,
	.address_list	= normal_i2c,
};

/*-----------------------------------------------------------------------*/

/* register access */

/*
 * All registers are word-sized, except for the configuration register.
 * LM75 uses a high-byte first convention, which is exactly opposite to
 * the SMBus standard.
 */
static int lm75_read_value(struct i2c_client *client, u8 reg)
{
	if (reg == LM75_REG_CONF)
		return i2c_smbus_read_byte_data(client, reg);
	else
		return i2c_smbus_read_word_swapped(client, reg);
}

static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
{
	if (reg == LM75_REG_CONF)
		return i2c_smbus_write_byte_data(client, reg, value);
	else
		return i2c_smbus_write_word_swapped(client, reg, value);
}

static struct lm75_data *lm75_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm75_data *data = i2c_get_clientdata(client);
	struct lm75_data *ret = data;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	    || !data->valid) {
		int i;
		dev_dbg(&client->dev, "Starting lm75 update\n");

		for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
			int status;

			status = lm75_read_value(client, LM75_REG_TEMP[i]);
			if (unlikely(status < 0)) {
				dev_dbg(dev,
					"LM75: Failed to read value: reg %d, error %d\n",
					LM75_REG_TEMP[i], status);
				ret = ERR_PTR(status);
				data->valid = 0;
				goto abort;
			}
			data->temp[i] = status;
		}
		data->last_updated = jiffies;
		data->valid = 1;
	}

abort:
	mutex_unlock(&data->update_lock);
	return ret;
}

module_i2c_driver(lm75_driver);

MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
MODULE_DESCRIPTION("LM75 driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4	1	/*
caaa0f36 S	2	* lm75.c - Part of lm_sensors, Linux kernel modules for hardware
	3	* monitoring
	4	* Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*/
1da177e4	20
1da177e4 LT	21	#include <linux/module.h>
	22	#include <linux/init.h>
	23	#include <linux/slab.h>
	24	#include <linux/jiffies.h>
	25	#include <linux/i2c.h>
943b0830	26	#include <linux/hwmon.h>
9ca8e40c	27	#include <linux/hwmon-sysfs.h>
943b0830	28	#include <linux/err.h>
9a61bf63	29	#include <linux/mutex.h>
1da177e4 LT	30	#include "lm75.h"
	31
	32
01a52397 DB	33	/*
01a52397 DB	34	* This driver handles the LM75 and compatible digital temperature sensors.
01a52397 DB	35	*/
01a52397 DB	36
9ebd3d82	37	enum lm75_type { /* keep sorted in alphabetical order */
e96f9d89	38	adt75,
1f86df49	39	ds1775,
9ebd3d82	40	ds75,
1f86df49	41	lm75,
9ebd3d82 DB	42	lm75a,
	43	max6625,
	44	max6626,
	45	mcp980x,
	46	stds75,
	47	tcn75,
	48	tmp100,
	49	tmp101,
6d034059	50	tmp105,
9ebd3d82 DB	51	tmp175,
	52	tmp275,
	53	tmp75,
	54	};
	55
8ff69eeb	56	/* Addresses scanned */
25e9c86d	57	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
1da177e4	58	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
1da177e4	59
1da177e4 LT	60
1da177e4 LT	61	/* The LM75 registers */
1da177e4	62	#define LM75_REG_CONF 0x01
9ca8e40c JD	63	static const u8 LM75_REG_TEMP[3] = {
	64	0x00, /* input */
	65	0x03, /* max */
	66	0x02, /* hyst */
	67	};
1da177e4 LT	68
	69	/* Each client has this additional data */
	70	struct lm75_data {
01a52397	71	struct device *hwmon_dev;
9a61bf63	72	struct mutex update_lock;
9ebd3d82	73	u8 orig_conf;
01a52397	74	char valid; /* !=0 if registers are valid */
1da177e4	75	unsigned long last_updated; /* In jiffies */
9ca8e40c JD	76	u16 temp[3]; /* Register values,
	77	0 = input
	78	1 = max
	79	2 = hyst */
1da177e4 LT	80	};
1da177e4 LT	81
1da177e4 LT	82	static int lm75_read_value(struct i2c_client *client, u8 reg);
	83	static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
	84	static struct lm75_data lm75_update_device(struct device dev);
	85
	86
01a52397 DB	87	/-----------------------------------------------------------------------/
	88
	89	/* sysfs attributes for hwmon */
1da177e4	90
9ca8e40c JD	91	static ssize_t show_temp(struct device dev, struct device_attribute da,
	92	char *buf)
	93	{
	94	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	95	struct lm75_data *data = lm75_update_device(dev);
1f962f36 FM	96
	97	if (IS_ERR(data))
	98	return PTR_ERR(data);
	99
9ca8e40c JD	100	return sprintf(buf, "%d\n",
9ca8e40c JD	101	LM75_TEMP_FROM_REG(data->temp[attr->index]));
1da177e4	102	}
9ca8e40c JD	103
	104	static ssize_t set_temp(struct device dev, struct device_attribute da,
	105	const char *buf, size_t count)
	106	{
	107	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	108	struct i2c_client *client = to_i2c_client(dev);
	109	struct lm75_data *data = i2c_get_clientdata(client);
	110	int nr = attr->index;
e3cd9528 S	111	long temp;
	112	int error;
	113
24edc0a7	114	error = kstrtol(buf, 10, &temp);
e3cd9528 S	115	if (error)
e3cd9528 S	116	return error;
9ca8e40c JD	117
	118	mutex_lock(&data->update_lock);
	119	data->temp[nr] = LM75_TEMP_TO_REG(temp);
	120	lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
	121	mutex_unlock(&data->update_lock);
	122	return count;
1da177e4	123	}
1da177e4	124
9ca8e40c JD	125	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
	126	show_temp, set_temp, 1);
	127	static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR \| S_IRUGO,
	128	show_temp, set_temp, 2);
	129	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
1da177e4	130
c1685f61	131	static struct attribute *lm75_attributes[] = {
9ca8e40c JD	132	&sensor_dev_attr_temp1_input.dev_attr.attr,
	133	&sensor_dev_attr_temp1_max.dev_attr.attr,
	134	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
c1685f61 MH	135
	136	NULL
	137	};
	138
	139	static const struct attribute_group lm75_group = {
	140	.attrs = lm75_attributes,
	141	};
	142
01a52397 DB	143	/-----------------------------------------------------------------------/
01a52397 DB	144
8ff69eeb	145	/* device probe and removal */
9ebd3d82 DB	146
	147	static int
	148	lm75_probe(struct i2c_client client, const struct i2c_device_id id)
	149	{
	150	struct lm75_data *data;
	151	int status;
	152	u8 set_mask, clr_mask;
	153	int new;
	154
	155	if (!i2c_check_functionality(client->adapter,
	156	I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_WORD_DATA))
	157	return -EIO;
	158
13ac7a01	159	data = devm_kzalloc(&client->dev, sizeof(struct lm75_data), GFP_KERNEL);
9ebd3d82 DB	160	if (!data)
	161	return -ENOMEM;
	162
	163	i2c_set_clientdata(client, data);
9ebd3d82 DB	164	mutex_init(&data->update_lock);
	165
	166	/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
	167	* Then tweak to be more precise when appropriate.
	168	*/
	169	set_mask = 0;
	170	clr_mask = (1 << 0) /* continuous conversions */
	171	\| (1 << 6) \| (1 << 5); /* 9-bit mode */
	172
	173	/* configure as specified */
	174	status = lm75_read_value(client, LM75_REG_CONF);
	175	if (status < 0) {
	176	dev_dbg(&client->dev, "Can't read config? %d\n", status);
13ac7a01	177	return status;
9ebd3d82 DB	178	}
	179	data->orig_conf = status;
	180	new = status & ~clr_mask;
	181	new \|= set_mask;
	182	if (status != new)
	183	lm75_write_value(client, LM75_REG_CONF, new);
	184	dev_dbg(&client->dev, "Config %02x\n", new);
	185
	186	/* Register sysfs hooks */
	187	status = sysfs_create_group(&client->dev.kobj, &lm75_group);
	188	if (status)
13ac7a01	189	return status;
9ebd3d82 DB	190
	191	data->hwmon_dev = hwmon_device_register(&client->dev);
	192	if (IS_ERR(data->hwmon_dev)) {
	193	status = PTR_ERR(data->hwmon_dev);
	194	goto exit_remove;
	195	}
	196
	197	dev_info(&client->dev, "%s: sensor '%s'\n",
739cf3a2	198	dev_name(data->hwmon_dev), client->name);
9ebd3d82 DB	199
	200	return 0;
	201
	202	exit_remove:
	203	sysfs_remove_group(&client->dev.kobj, &lm75_group);
9ebd3d82 DB	204	return status;
	205	}
	206
	207	static int lm75_remove(struct i2c_client *client)
	208	{
	209	struct lm75_data *data = i2c_get_clientdata(client);
	210
	211	hwmon_device_unregister(data->hwmon_dev);
	212	sysfs_remove_group(&client->dev.kobj, &lm75_group);
	213	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
9ebd3d82 DB	214	return 0;
	215	}
	216
	217	static const struct i2c_device_id lm75_ids[] = {
e96f9d89	218	{ "adt75", adt75, },
9ebd3d82 DB	219	{ "ds1775", ds1775, },
	220	{ "ds75", ds75, },
	221	{ "lm75", lm75, },
	222	{ "lm75a", lm75a, },
	223	{ "max6625", max6625, },
	224	{ "max6626", max6626, },
	225	{ "mcp980x", mcp980x, },
	226	{ "stds75", stds75, },
	227	{ "tcn75", tcn75, },
	228	{ "tmp100", tmp100, },
	229	{ "tmp101", tmp101, },
6d034059	230	{ "tmp105", tmp105, },
9ebd3d82 DB	231	{ "tmp175", tmp175, },
	232	{ "tmp275", tmp275, },
	233	{ "tmp75", tmp75, },
	234	{ /* LIST END */ }
	235	};
	236	MODULE_DEVICE_TABLE(i2c, lm75_ids);
	237
05e82fe4 LS	238	#define LM75A_ID 0xA1
05e82fe4 LS	239
8ff69eeb	240	/* Return 0 if detection is successful, -ENODEV otherwise */
310ec792	241	static int lm75_detect(struct i2c_client *new_client,
8ff69eeb	242	struct i2c_board_info *info)
1da177e4	243	{
8ff69eeb	244	struct i2c_adapter *adapter = new_client->adapter;
1da177e4	245	int i;
e76f67b5	246	int conf, hyst, os;
05e82fe4	247	bool is_lm75a = 0;
1da177e4	248
1da177e4 LT	249	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
1da177e4 LT	250	I2C_FUNC_SMBUS_WORD_DATA))
8ff69eeb	251	return -ENODEV;
1da177e4	252
426343ef JD	253	/*
	254	* Now, we do the remaining detection. There is no identification-
	255	* dedicated register so we have to rely on several tricks:
	256	* unused bits, registers cycling over 8-address boundaries,
	257	* addresses 0x04-0x07 returning the last read value.
	258	* The cycling+unused addresses combination is not tested,
	259	* since it would significantly slow the detection down and would
	260	* hardly add any value.
	261	*
	262	* The National Semiconductor LM75A is different than earlier
	263	* LM75s. It has an ID byte of 0xaX (where X is the chip
	264	* revision, with 1 being the only revision in existence) in
	265	* register 7, and unused registers return 0xff rather than the
	266	* last read value.
	267	*
	268	* Note that this function only detects the original National
	269	* Semiconductor LM75 and the LM75A. Clones from other vendors
	270	* aren't detected, on purpose, because they are typically never
	271	* found on PC hardware. They are found on embedded designs where
	272	* they can be instantiated explicitly so detection is not needed.
	273	* The absence of identification registers on all these clones
	274	* would make their exhaustive detection very difficult and weak,
	275	* and odds are that the driver would bind to unsupported devices.
	276	*/
1da177e4	277
e76f67b5	278	/* Unused bits */
52df6440	279	conf = i2c_smbus_read_byte_data(new_client, 1);
e76f67b5 JD	280	if (conf & 0xe0)
e76f67b5 JD	281	return -ENODEV;
05e82fe4 LS	282
	283	/* First check for LM75A */
	284	if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
	285	/* LM75A returns 0xff on unused registers so
	286	just to be sure we check for that too. */
	287	if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
	288	\|\| i2c_smbus_read_byte_data(new_client, 5) != 0xff
	289	\|\| i2c_smbus_read_byte_data(new_client, 6) != 0xff)
	290	return -ENODEV;
	291	is_lm75a = 1;
e76f67b5 JD	292	hyst = i2c_smbus_read_byte_data(new_client, 2);
e76f67b5 JD	293	os = i2c_smbus_read_byte_data(new_client, 3);
05e82fe4 LS	294	} else { /* Traditional style LM75 detection */
05e82fe4 LS	295	/* Unused addresses */
e76f67b5 JD	296	hyst = i2c_smbus_read_byte_data(new_client, 2);
	297	if (i2c_smbus_read_byte_data(new_client, 4) != hyst
	298	\|\| i2c_smbus_read_byte_data(new_client, 5) != hyst
	299	\|\| i2c_smbus_read_byte_data(new_client, 6) != hyst
	300	\|\| i2c_smbus_read_byte_data(new_client, 7) != hyst)
05e82fe4	301	return -ENODEV;
e76f67b5 JD	302	os = i2c_smbus_read_byte_data(new_client, 3);
	303	if (i2c_smbus_read_byte_data(new_client, 4) != os
	304	\|\| i2c_smbus_read_byte_data(new_client, 5) != os
	305	\|\| i2c_smbus_read_byte_data(new_client, 6) != os
	306	\|\| i2c_smbus_read_byte_data(new_client, 7) != os)
05e82fe4 LS	307	return -ENODEV;
05e82fe4 LS	308	}
1da177e4	309
52df6440	310	/* Addresses cycling */
e76f67b5	311	for (i = 8; i <= 248; i += 40) {
52df6440	312	if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
e76f67b5 JD	313	\|\| i2c_smbus_read_byte_data(new_client, i + 2) != hyst
e76f67b5 JD	314	\|\| i2c_smbus_read_byte_data(new_client, i + 3) != os)
52df6440	315	return -ENODEV;
05e82fe4 LS	316	if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
	317	!= LM75A_ID)
	318	return -ENODEV;
1da177e4 LT	319	}
1da177e4 LT	320
05e82fe4	321	strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
c1685f61	322
1da177e4	323	return 0;
01a52397 DB	324	}
01a52397 DB	325
9914518e SD	326	#ifdef CONFIG_PM
	327	static int lm75_suspend(struct device *dev)
	328	{
	329	int status;
	330	struct i2c_client *client = to_i2c_client(dev);
	331	status = lm75_read_value(client, LM75_REG_CONF);
	332	if (status < 0) {
	333	dev_dbg(&client->dev, "Can't read config? %d\n", status);
	334	return status;
	335	}
	336	status = status \| LM75_SHUTDOWN;
	337	lm75_write_value(client, LM75_REG_CONF, status);
	338	return 0;
	339	}
	340
	341	static int lm75_resume(struct device *dev)
	342	{
	343	int status;
	344	struct i2c_client *client = to_i2c_client(dev);
	345	status = lm75_read_value(client, LM75_REG_CONF);
	346	if (status < 0) {
	347	dev_dbg(&client->dev, "Can't read config? %d\n", status);
	348	return status;
	349	}
	350	status = status & ~LM75_SHUTDOWN;
	351	lm75_write_value(client, LM75_REG_CONF, status);
	352	return 0;
	353	}
	354
	355	static const struct dev_pm_ops lm75_dev_pm_ops = {
	356	.suspend = lm75_suspend,
	357	.resume = lm75_resume,
	358	};
	359	#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
	360	#else
	361	#define LM75_DEV_PM_OPS NULL
	362	#endif /* CONFIG_PM */
	363
8ff69eeb JD	364	static struct i2c_driver lm75_driver = {
8ff69eeb JD	365	.class = I2C_CLASS_HWMON,
01a52397	366	.driver = {
8ff69eeb	367	.name = "lm75",
9914518e	368	.pm = LM75_DEV_PM_OPS,
01a52397	369	},
8ff69eeb JD	370	.probe = lm75_probe,
	371	.remove = lm75_remove,
	372	.id_table = lm75_ids,
	373	.detect = lm75_detect,
c3813d6a	374	.address_list = normal_i2c,
01a52397 DB	375	};
	376
	377	/-----------------------------------------------------------------------/
	378
	379	/* register access */
	380
caaa0f36 S	381	/*
	382	* All registers are word-sized, except for the configuration register.
	383	* LM75 uses a high-byte first convention, which is exactly opposite to
	384	* the SMBus standard.
	385	*/
1da177e4 LT	386	static int lm75_read_value(struct i2c_client *client, u8 reg)
	387	{
	388	if (reg == LM75_REG_CONF)
	389	return i2c_smbus_read_byte_data(client, reg);
90f4102c JD	390	else
90f4102c JD	391	return i2c_smbus_read_word_swapped(client, reg);
1da177e4 LT	392	}
1da177e4 LT	393
1da177e4 LT	394	static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
	395	{
	396	if (reg == LM75_REG_CONF)
	397	return i2c_smbus_write_byte_data(client, reg, value);
	398	else
90f4102c	399	return i2c_smbus_write_word_swapped(client, reg, value);
1da177e4 LT	400	}
1da177e4 LT	401
1da177e4 LT	402	static struct lm75_data lm75_update_device(struct device dev)
	403	{
	404	struct i2c_client *client = to_i2c_client(dev);
	405	struct lm75_data *data = i2c_get_clientdata(client);
1f962f36	406	struct lm75_data *ret = data;
1da177e4	407
9a61bf63	408	mutex_lock(&data->update_lock);
1da177e4 LT	409
	410	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	411	\|\| !data->valid) {
9ca8e40c	412	int i;
1da177e4 LT	413	dev_dbg(&client->dev, "Starting lm75 update\n");
1da177e4 LT	414
bcccc3a2 DB	415	for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
	416	int status;
	417
	418	status = lm75_read_value(client, LM75_REG_TEMP[i]);
1f962f36 FM	419	if (unlikely(status < 0)) {
	420	dev_dbg(dev,
	421	"LM75: Failed to read value: reg %d, error %d\n",
	422	LM75_REG_TEMP[i], status);
	423	ret = ERR_PTR(status);
	424	data->valid = 0;
	425	goto abort;
	426	}
	427	data->temp[i] = status;
bcccc3a2	428	}
1da177e4 LT	429	data->last_updated = jiffies;
	430	data->valid = 1;
	431	}
	432
1f962f36	433	abort:
9a61bf63	434	mutex_unlock(&data->update_lock);
1f962f36	435	return ret;
1da177e4 LT	436	}
1da177e4 LT	437
f0967eea	438	module_i2c_driver(lm75_driver);
1da177e4 LT	439
	440	MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
	441	MODULE_DESCRIPTION("LM75 driver");
	442	MODULE_LICENSE("GPL");