[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.
 * Only types which are _not_ listed in I2C_CLIENT_INSMOD_*() need to be
 * listed here.  We start at 9 since I2C_CLIENT_INSMOD_*() currently allow
 * definition of up to 8 chip types (plus zero).
 */

enum lm75_type {		/* keep sorted in alphabetical order */
	ds1775 = 9,
	ds75,
	/* lm75 -- in I2C_CLIENT_INSMOD_1() */
	lm75a,
	max6625,
	max6626,
	mcp980x,
	stds75,
	tcn75,
	tmp100,
	tmp101,
	tmp175,
	tmp275,
	tmp75,
};

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

/* Insmod parameters (only for legacy style driver binding) */
I2C_CLIENT_INSMOD_1(lm75);


/* 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 i2c_client	*client;
	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);
	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 = simple_strtol(buf, NULL, 10);

	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,
};

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

/* "New style" I2C driver binding -- following the driver model */

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 = kzalloc(sizeof(struct lm75_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	i2c_set_clientdata(client, data);

	data->client = client;
	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);
		goto exit_free;
	}
	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)
		goto exit_free;

	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",
		data->hwmon_dev->bus_id, client->name);

	return 0;

exit_remove:
	sysfs_remove_group(&client->dev.kobj, &lm75_group);
exit_free:
	i2c_set_clientdata(client, NULL);
	kfree(data);
	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);
	i2c_set_clientdata(client, NULL);
	kfree(data);
	return 0;
}

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

static struct i2c_driver lm75_driver = {
	.driver = {
		.name	= "lm75",
	},
	.probe		= lm75_probe,
	.remove		= lm75_remove,
	.id_table	= lm75_ids,
};

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

/* "Legacy" I2C driver binding */

static struct i2c_driver lm75_legacy_driver;

/* This function is called by i2c_probe */
static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
{
	int i;
	struct i2c_client *new_client;
	int err = 0;

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

	/* OK. For now, we presume we have a valid address. We create the
	   client structure, even though there may be no sensor present.
	   But it allows us to use i2c_smbus_read_*_data() calls. */
	new_client = kzalloc(sizeof *new_client, GFP_KERNEL);
	if (!new_client) {
		err = -ENOMEM;
		goto exit;
	}

	new_client->addr = address;
	new_client->adapter = adapter;
	new_client->driver = &lm75_legacy_driver;
	new_client->flags = 0;

	/* 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. */
	if (kind < 0) {
		int cur, conf, hyst, os;

		/* Unused addresses */
		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);
		if (i2c_smbus_read_word_data(new_client, 4) != hyst
		 || i2c_smbus_read_word_data(new_client, 5) != hyst
		 || i2c_smbus_read_word_data(new_client, 6) != hyst
		 || i2c_smbus_read_word_data(new_client, 7) != hyst)
			goto exit_free;
		os = i2c_smbus_read_word_data(new_client, 3);
		if (i2c_smbus_read_word_data(new_client, 4) != os
		 || i2c_smbus_read_word_data(new_client, 5) != os
		 || i2c_smbus_read_word_data(new_client, 6) != os
		 || i2c_smbus_read_word_data(new_client, 7) != os)
			goto exit_free;

		/* Unused bits */
		if (conf & 0xe0)
			goto exit_free;

		/* Addresses cycling */
		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) != os)
				goto exit_free;
	}

	/* NOTE: we treat "force=..." and "force_lm75=..." the same.
	 * Only new-style driver binding distinguishes chip types.
	 */
	strlcpy(new_client->name, "lm75", I2C_NAME_SIZE);

	/* Tell the I2C layer a new client has arrived */
	err = i2c_attach_client(new_client);
	if (err)
		goto exit_free;

	err = lm75_probe(new_client, NULL);
	if (err < 0)
		goto exit_detach;

	return 0;

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

static int lm75_attach_adapter(struct i2c_adapter *adapter)
{
	if (!(adapter->class & I2C_CLASS_HWMON))
		return 0;
	return i2c_probe(adapter, &addr_data, lm75_detect);
}

static int lm75_detach_client(struct i2c_client *client)
{
	lm75_remove(client);
	i2c_detach_client(client);
	kfree(client);
	return 0;
}

static struct i2c_driver lm75_legacy_driver = {
	.driver = {
		.name	= "lm75_legacy",
	},
	.attach_adapter	= lm75_attach_adapter,
	.detach_client	= lm75_detach_client,
};

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

/* 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)
{
	int value;

	if (reg == LM75_REG_CONF)
		return i2c_smbus_read_byte_data(client, reg);

	value = i2c_smbus_read_word_data(client, reg);
	return (value < 0) ? value : swab16(value);
}

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_data(client, reg, swab16(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);

	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 (status < 0)
				dev_dbg(&client->dev, "reg %d, err %d\n",
						LM75_REG_TEMP[i], status);
			else
				data->temp[i] = status;
		}
		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

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

/* module glue */

static int __init sensors_lm75_init(void)
{
	int status;

	status = i2c_add_driver(&lm75_driver);
	if (status < 0)
		return status;

	status = i2c_add_driver(&lm75_legacy_driver);
	if (status < 0)
		i2c_del_driver(&lm75_driver);

	return status;
}

static void __exit sensors_lm75_exit(void)
{
	i2c_del_driver(&lm75_legacy_driver);
	i2c_del_driver(&lm75_driver);
}

MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
MODULE_DESCRIPTION("LM75 driver");
MODULE_LICENSE("GPL");

module_init(sensors_lm75_init);
module_exit(sensors_lm75_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	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	*/
	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.
9ebd3d82 DB	35	* Only types which are _not_ listed in I2C_CLIENT_INSMOD_*() need to be
	36	* listed here. We start at 9 since I2C_CLIENT_INSMOD_*() currently allow
	37	* definition of up to 8 chip types (plus zero).
01a52397 DB	38	*/
01a52397 DB	39
9ebd3d82 DB	40	enum lm75_type { /* keep sorted in alphabetical order */
	41	ds1775 = 9,
	42	ds75,
	43	/* lm75 -- in I2C_CLIENT_INSMOD_1() */
	44	lm75a,
	45	max6625,
	46	max6626,
	47	mcp980x,
	48	stds75,
	49	tcn75,
	50	tmp100,
	51	tmp101,
	52	tmp175,
	53	tmp275,
	54	tmp75,
	55	};
	56
01a52397	57	/* Addresses scanned by legacy style driver binding */
25e9c86d	58	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
1da177e4	59	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
1da177e4	60
01a52397	61	/* Insmod parameters (only for legacy style driver binding) */
f4b50261	62	I2C_CLIENT_INSMOD_1(lm75);
1da177e4	63
1da177e4 LT	64
1da177e4 LT	65	/* The LM75 registers */
1da177e4	66	#define LM75_REG_CONF 0x01
9ca8e40c JD	67	static const u8 LM75_REG_TEMP[3] = {
	68	0x00, /* input */
	69	0x03, /* max */
	70	0x02, /* hyst */
	71	};
1da177e4 LT	72
	73	/* Each client has this additional data */
	74	struct lm75_data {
9ebd3d82	75	struct i2c_client *client;
01a52397	76	struct device *hwmon_dev;
9a61bf63	77	struct mutex update_lock;
9ebd3d82	78	u8 orig_conf;
01a52397	79	char valid; /* !=0 if registers are valid */
1da177e4	80	unsigned long last_updated; /* In jiffies */
9ca8e40c JD	81	u16 temp[3]; /* Register values,
	82	0 = input
	83	1 = max
	84	2 = hyst */
1da177e4 LT	85	};
1da177e4 LT	86
1da177e4 LT	87	static int lm75_read_value(struct i2c_client *client, u8 reg);
	88	static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
	89	static struct lm75_data lm75_update_device(struct device dev);
	90
	91
01a52397 DB	92	/-----------------------------------------------------------------------/
	93
	94	/* sysfs attributes for hwmon */
1da177e4	95
9ca8e40c JD	96	static ssize_t show_temp(struct device dev, struct device_attribute da,
	97	char *buf)
	98	{
	99	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	100	struct lm75_data *data = lm75_update_device(dev);
	101	return sprintf(buf, "%d\n",
	102	LM75_TEMP_FROM_REG(data->temp[attr->index]));
1da177e4	103	}
9ca8e40c JD	104
	105	static ssize_t set_temp(struct device dev, struct device_attribute da,
	106	const char *buf, size_t count)
	107	{
	108	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	109	struct i2c_client *client = to_i2c_client(dev);
	110	struct lm75_data *data = i2c_get_clientdata(client);
	111	int nr = attr->index;
5bfedac0	112	long temp = simple_strtol(buf, NULL, 10);
9ca8e40c JD	113
	114	mutex_lock(&data->update_lock);
	115	data->temp[nr] = LM75_TEMP_TO_REG(temp);
	116	lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
	117	mutex_unlock(&data->update_lock);
	118	return count;
1da177e4	119	}
1da177e4	120
9ca8e40c JD	121	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
	122	show_temp, set_temp, 1);
	123	static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR \| S_IRUGO,
	124	show_temp, set_temp, 2);
	125	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
1da177e4	126
c1685f61	127	static struct attribute *lm75_attributes[] = {
9ca8e40c JD	128	&sensor_dev_attr_temp1_input.dev_attr.attr,
	129	&sensor_dev_attr_temp1_max.dev_attr.attr,
	130	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
c1685f61 MH	131
	132	NULL
	133	};
	134
	135	static const struct attribute_group lm75_group = {
	136	.attrs = lm75_attributes,
	137	};
	138
01a52397 DB	139	/-----------------------------------------------------------------------/
01a52397 DB	140
9ebd3d82 DB	141	/* "New style" I2C driver binding -- following the driver model */
	142
	143	static int
	144	lm75_probe(struct i2c_client client, const struct i2c_device_id id)
	145	{
	146	struct lm75_data *data;
	147	int status;
	148	u8 set_mask, clr_mask;
	149	int new;
	150
	151	if (!i2c_check_functionality(client->adapter,
	152	I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_WORD_DATA))
	153	return -EIO;
	154
	155	data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL);
	156	if (!data)
	157	return -ENOMEM;
	158
	159	i2c_set_clientdata(client, data);
	160
	161	data->client = client;
	162	mutex_init(&data->update_lock);
	163
	164	/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
	165	* Then tweak to be more precise when appropriate.
	166	*/
	167	set_mask = 0;
	168	clr_mask = (1 << 0) /* continuous conversions */
	169	\| (1 << 6) \| (1 << 5); /* 9-bit mode */
	170
	171	/* configure as specified */
	172	status = lm75_read_value(client, LM75_REG_CONF);
	173	if (status < 0) {
	174	dev_dbg(&client->dev, "Can't read config? %d\n", status);
	175	goto exit_free;
	176	}
	177	data->orig_conf = status;
	178	new = status & ~clr_mask;
	179	new \|= set_mask;
	180	if (status != new)
	181	lm75_write_value(client, LM75_REG_CONF, new);
	182	dev_dbg(&client->dev, "Config %02x\n", new);
	183
	184	/* Register sysfs hooks */
	185	status = sysfs_create_group(&client->dev.kobj, &lm75_group);
	186	if (status)
	187	goto exit_free;
	188
	189	data->hwmon_dev = hwmon_device_register(&client->dev);
	190	if (IS_ERR(data->hwmon_dev)) {
	191	status = PTR_ERR(data->hwmon_dev);
	192	goto exit_remove;
	193	}
	194
	195	dev_info(&client->dev, "%s: sensor '%s'\n",
	196	data->hwmon_dev->bus_id, client->name);
	197
	198	return 0;
	199
	200	exit_remove:
	201	sysfs_remove_group(&client->dev.kobj, &lm75_group);
	202	exit_free:
	203	i2c_set_clientdata(client, NULL);
	204	kfree(data);
205	return status;
206	}
207
208	static int lm75_remove(struct i2c_client *client)
209	{
210	struct lm75_data *data = i2c_get_clientdata(client);
211
212	hwmon_device_unregister(data->hwmon_dev);
213	sysfs_remove_group(&client->dev.kobj, &lm75_group);
214	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
215	i2c_set_clientdata(client, NULL);
216	kfree(data);
217	return 0;
218	}
219
220	static const struct i2c_device_id lm75_ids[] = {
221	{ "ds1775", ds1775, },
222	{ "ds75", ds75, },
223	{ "lm75", lm75, },
224	{ "lm75a", lm75a, },
225	{ "max6625", max6625, },
226	{ "max6626", max6626, },
227	{ "mcp980x", mcp980x, },
228	{ "stds75", stds75, },
229	{ "tcn75", tcn75, },
230	{ "tmp100", tmp100, },
231	{ "tmp101", tmp101, },
232	{ "tmp175", tmp175, },
233	{ "tmp275", tmp275, },
234	{ "tmp75", tmp75, },
235	{ /* LIST END */ }
236	};
237	MODULE_DEVICE_TABLE(i2c, lm75_ids);
238
239	static struct i2c_driver lm75_driver = {
240	.driver = {
241	.name = "lm75",
242	},
243	.probe = lm75_probe,
244	.remove = lm75_remove,
245	.id_table = lm75_ids,
246	};
247
248	/-----------------------------------------------------------------------/
249
01a52397 DB	250	/* "Legacy" I2C driver binding */
01a52397 DB	251
9ebd3d82	252	static struct i2c_driver lm75_legacy_driver;
01a52397	253
2ed2dc3c	254	/* This function is called by i2c_probe */
1da177e4 LT	255	static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
	256	{
	257	int i;
	258	struct i2c_client *new_client;
1da177e4	259	int err = 0;
1da177e4	260
1da177e4 LT	261	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
	262	I2C_FUNC_SMBUS_WORD_DATA))
	263	goto exit;
	264
01a52397 DB	265	/* OK. For now, we presume we have a valid address. We create the
	266	client structure, even though there may be no sensor present.
	267	But it allows us to use i2c_smbus_read__data() calls. /
9ebd3d82 DB	268	new_client = kzalloc(sizeof *new_client, GFP_KERNEL);
9ebd3d82 DB	269	if (!new_client) {
1da177e4 LT	270	err = -ENOMEM;
	271	goto exit;
	272	}
1da177e4	273
1da177e4 LT	274	new_client->addr = address;
1da177e4 LT	275	new_client->adapter = adapter;
9ebd3d82	276	new_client->driver = &lm75_legacy_driver;
1da177e4 LT	277	new_client->flags = 0;
	278
	279	/* Now, we do the remaining detection. There is no identification-
	280	dedicated register so we have to rely on several tricks:
	281	unused bits, registers cycling over 8-address boundaries,
	282	addresses 0x04-0x07 returning the last read value.
	283	The cycling+unused addresses combination is not tested,
	284	since it would significantly slow the detection down and would
	285	hardly add any value. */
	286	if (kind < 0) {
	287	int cur, conf, hyst, os;
	288
	289	/* Unused addresses */
	290	cur = i2c_smbus_read_word_data(new_client, 0);
	291	conf = i2c_smbus_read_byte_data(new_client, 1);
	292	hyst = i2c_smbus_read_word_data(new_client, 2);
	293	if (i2c_smbus_read_word_data(new_client, 4) != hyst
	294	\|\| i2c_smbus_read_word_data(new_client, 5) != hyst
	295	\|\| i2c_smbus_read_word_data(new_client, 6) != hyst
	296	\|\| i2c_smbus_read_word_data(new_client, 7) != hyst)
01a52397	297	goto exit_free;
1da177e4 LT	298	os = i2c_smbus_read_word_data(new_client, 3);
	299	if (i2c_smbus_read_word_data(new_client, 4) != os
	300	\|\| i2c_smbus_read_word_data(new_client, 5) != os
	301	\|\| i2c_smbus_read_word_data(new_client, 6) != os
	302	\|\| i2c_smbus_read_word_data(new_client, 7) != os)
01a52397	303	goto exit_free;
1da177e4 LT	304
	305	/* Unused bits */
	306	if (conf & 0xe0)
01a52397	307	goto exit_free;
1da177e4 LT	308
	309	/* Addresses cycling */
	310	for (i = 8; i < 0xff; i += 8)
	311	if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
	312	\|\| i2c_smbus_read_word_data(new_client, i + 2) != hyst
	313	\|\| i2c_smbus_read_word_data(new_client, i + 3) != os)
	314	goto exit_free;
	315	}
	316
9ebd3d82 DB	317	/* NOTE: we treat "force=..." and "force_lm75=..." the same.
	318	* Only new-style driver binding distinguishes chip types.
	319	*/
01a52397	320	strlcpy(new_client->name, "lm75", I2C_NAME_SIZE);
1da177e4	321
1da177e4	322	/* Tell the I2C layer a new client has arrived */
9ebd3d82 DB	323	err = i2c_attach_client(new_client);
9ebd3d82 DB	324	if (err)
1da177e4 LT	325	goto exit_free;
1da177e4 LT	326
9ebd3d82 DB	327	err = lm75_probe(new_client, NULL);
9ebd3d82 DB	328	if (err < 0)
c1685f61 MH	329	goto exit_detach;
c1685f61 MH	330
1da177e4 LT	331	return 0;
1da177e4 LT	332
943b0830 MH	333	exit_detach:
943b0830 MH	334	i2c_detach_client(new_client);
1da177e4	335	exit_free:
9ebd3d82	336	kfree(new_client);
1da177e4 LT	337	exit:
	338	return err;
	339	}
	340
01a52397 DB	341	static int lm75_attach_adapter(struct i2c_adapter *adapter)
	342	{
	343	if (!(adapter->class & I2C_CLASS_HWMON))
	344	return 0;
	345	return i2c_probe(adapter, &addr_data, lm75_detect);
	346	}
	347
1da177e4 LT	348	static int lm75_detach_client(struct i2c_client *client)
1da177e4 LT	349	{
9ebd3d82	350	lm75_remove(client);
1da177e4	351	i2c_detach_client(client);
9ebd3d82	352	kfree(client);
1da177e4 LT	353	return 0;
	354	}
	355
9ebd3d82	356	static struct i2c_driver lm75_legacy_driver = {
01a52397	357	.driver = {
9ebd3d82	358	.name = "lm75_legacy",
01a52397 DB	359	},
	360	.attach_adapter = lm75_attach_adapter,
	361	.detach_client = lm75_detach_client,
	362	};
	363
	364	/-----------------------------------------------------------------------/
	365
	366	/* register access */
	367
1da177e4 LT	368	/* All registers are word-sized, except for the configuration register.
1da177e4 LT	369	LM75 uses a high-byte first convention, which is exactly opposite to
ccd6befc	370	the SMBus standard. */
1da177e4 LT	371	static int lm75_read_value(struct i2c_client *client, u8 reg)
1da177e4 LT	372	{
bcccc3a2 DB	373	int value;
bcccc3a2 DB	374
1da177e4 LT	375	if (reg == LM75_REG_CONF)
1da177e4 LT	376	return i2c_smbus_read_byte_data(client, reg);
bcccc3a2 DB	377
	378	value = i2c_smbus_read_word_data(client, reg);
	379	return (value < 0) ? value : swab16(value);
1da177e4 LT	380	}
1da177e4 LT	381
1da177e4 LT	382	static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
	383	{
	384	if (reg == LM75_REG_CONF)
	385	return i2c_smbus_write_byte_data(client, reg, value);
	386	else
	387	return i2c_smbus_write_word_data(client, reg, swab16(value));
	388	}
	389
1da177e4 LT	390	static struct lm75_data lm75_update_device(struct device dev)
	391	{
	392	struct i2c_client *client = to_i2c_client(dev);
	393	struct lm75_data *data = i2c_get_clientdata(client);
	394
9a61bf63	395	mutex_lock(&data->update_lock);
1da177e4 LT	396
	397	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	398	\|\| !data->valid) {
9ca8e40c	399	int i;
1da177e4 LT	400	dev_dbg(&client->dev, "Starting lm75 update\n");
1da177e4 LT	401
bcccc3a2 DB	402	for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
	403	int status;
	404
	405	status = lm75_read_value(client, LM75_REG_TEMP[i]);
	406	if (status < 0)
	407	dev_dbg(&client->dev, "reg %d, err %d\n",
	408	LM75_REG_TEMP[i], status);
	409	else
	410	data->temp[i] = status;
	411	}
1da177e4 LT	412	data->last_updated = jiffies;
	413	data->valid = 1;
	414	}
	415
9a61bf63	416	mutex_unlock(&data->update_lock);
1da177e4 LT	417
	418	return data;
	419	}
	420
01a52397 DB	421	/-----------------------------------------------------------------------/
	422
	423	/* module glue */
	424
1da177e4 LT	425	static int __init sensors_lm75_init(void)
1da177e4 LT	426	{
9ebd3d82 DB	427	int status;
	428
	429	status = i2c_add_driver(&lm75_driver);
	430	if (status < 0)
	431	return status;
	432
	433	status = i2c_add_driver(&lm75_legacy_driver);
	434	if (status < 0)
	435	i2c_del_driver(&lm75_driver);
	436
	437	return status;
1da177e4 LT	438	}
	439
	440	static void __exit sensors_lm75_exit(void)
	441	{
9ebd3d82	442	i2c_del_driver(&lm75_legacy_driver);
1da177e4 LT	443	i2c_del_driver(&lm75_driver);
	444	}
	445
	446	MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
	447	MODULE_DESCRIPTION("LM75 driver");
	448	MODULE_LICENSE("GPL");
	449
	450	module_init(sensors_lm75_init);
	451	module_exit(sensors_lm75_exit);