[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/err.h>
#include <linux/mutex.h>
#include "lm75.h"


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

/* Insmod parameters */
I2C_CLIENT_INSMOD_1(lm75);

/* Many LM75 constants specified below */

/* The LM75 registers */
#define LM75_REG_TEMP		0x00
#define LM75_REG_CONF		0x01
#define LM75_REG_TEMP_HYST	0x02
#define LM75_REG_TEMP_OS	0x03

/* Each client has this additional data */
struct lm75_data {
	struct i2c_client	client;
	struct class_device *class_dev;
	struct mutex		update_lock;
	char			valid;		/* !=0 if following fields are valid */
	unsigned long		last_updated;	/* In jiffies */
	u16			temp_input;	/* Register values */
	u16			temp_max;
	u16			temp_hyst;
};

static int lm75_attach_adapter(struct i2c_adapter *adapter);
static int lm75_detect(struct i2c_adapter *adapter, int address, int kind);
static void lm75_init_client(struct i2c_client *client);
static int lm75_detach_client(struct i2c_client *client);
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);


/* This is the driver that will be inserted */
static struct i2c_driver lm75_driver = {
	.driver = {
		.name	= "lm75",
	},
	.id		= I2C_DRIVERID_LM75,
	.attach_adapter	= lm75_attach_adapter,
	.detach_client	= lm75_detach_client,
};

#define show(value)	\
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)		\
{									\
	struct lm75_data *data = lm75_update_device(dev);		\
	return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value));	\
}
show(temp_max);
show(temp_hyst);
show(temp_input);

#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 lm75_data *data = i2c_get_clientdata(client);	\
	int temp = simple_strtoul(buf, NULL, 10);		\
								\
	mutex_lock(&data->update_lock);				\
	data->value = LM75_TEMP_TO_REG(temp);			\
	lm75_write_value(client, reg, data->value);		\
	mutex_unlock(&data->update_lock);					\
	return count;						\
}
set(temp_max, LM75_REG_TEMP_OS);
set(temp_hyst, LM75_REG_TEMP_HYST);

static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hyst, set_temp_hyst);
static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL);

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);
}

/* 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;
	struct lm75_data *data;
	int err = 0;
	const char *name = "";

	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 client. We now create the
	   client structure, even though we cannot fill it completely yet.
	   But it allows us to access lm75_{read,write}_value. */
	if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
		err = -ENOMEM;
		goto exit;
	}

	new_client = &data->client;
	i2c_set_clientdata(new_client, data);
	new_client->addr = address;
	new_client->adapter = adapter;
	new_client->driver = &lm75_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;
	}

	/* Determine the chip type - only one kind supported! */
	if (kind <= 0)
		kind = lm75;

	if (kind == lm75) {
		name = "lm75";
	}

	/* Fill in the remaining client fields and put it into the global list */
	strlcpy(new_client->name, name, I2C_NAME_SIZE);
	data->valid = 0;
	mutex_init(&data->update_lock);

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

	/* Initialize the LM75 chip */
	lm75_init_client(new_client);
	
	/* Register sysfs hooks */
	data->class_dev = hwmon_device_register(&new_client->dev);
	if (IS_ERR(data->class_dev)) {
		err = PTR_ERR(data->class_dev);
		goto exit_detach;
	}

	device_create_file(&new_client->dev, &dev_attr_temp1_max);
	device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
	device_create_file(&new_client->dev, &dev_attr_temp1_input);

	return 0;

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

static int lm75_detach_client(struct i2c_client *client)
{
	struct lm75_data *data = i2c_get_clientdata(client);
	hwmon_device_unregister(data->class_dev);
	i2c_detach_client(client);
	kfree(data);
	return 0;
}

/* All registers are word-sized, except for the configuration register.
   LM75 uses a high-byte first convention, which is exactly opposite to
   the usual practice. */
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 swab16(i2c_smbus_read_word_data(client, reg));
}

/* All registers are word-sized, except for the configuration register.
   LM75 uses a high-byte first convention, which is exactly opposite to
   the usual practice. */
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 void lm75_init_client(struct i2c_client *client)
{
	int reg;

	/* Enable if in shutdown mode */
	reg = lm75_read_value(client, LM75_REG_CONF);
	if (reg >= 0 && (reg & 0x01))
		lm75_write_value(client, LM75_REG_CONF, reg & 0xfe);
}

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) {
		dev_dbg(&client->dev, "Starting lm75 update\n");

		data->temp_input = lm75_read_value(client, LM75_REG_TEMP);
		data->temp_max = lm75_read_value(client, LM75_REG_TEMP_OS);
		data->temp_hyst = lm75_read_value(client, LM75_REG_TEMP_HYST);
		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

static int __init sensors_lm75_init(void)
{
	return i2c_add_driver(&lm75_driver);
}

static void __exit sensors_lm75_exit(void)
{
	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 MH	26	#include <linux/hwmon.h>
943b0830 MH	27	#include <linux/err.h>
9a61bf63	28	#include <linux/mutex.h>
1da177e4 LT	29	#include "lm75.h"
	30
	31
	32	/* Addresses to scan */
	33	static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
	34	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
1da177e4 LT	35
1da177e4 LT	36	/* Insmod parameters */
f4b50261	37	I2C_CLIENT_INSMOD_1(lm75);
1da177e4 LT	38
	39	/* Many LM75 constants specified below */
	40
	41	/* The LM75 registers */
	42	#define LM75_REG_TEMP 0x00
	43	#define LM75_REG_CONF 0x01
	44	#define LM75_REG_TEMP_HYST 0x02
	45	#define LM75_REG_TEMP_OS 0x03
	46
	47	/* Each client has this additional data */
	48	struct lm75_data {
	49	struct i2c_client client;
943b0830	50	struct class_device *class_dev;
9a61bf63	51	struct mutex update_lock;
1da177e4 LT	52	char valid; /* !=0 if following fields are valid */
	53	unsigned long last_updated; /* In jiffies */
	54	u16 temp_input; /* Register values */
	55	u16 temp_max;
	56	u16 temp_hyst;
	57	};
	58
	59	static int lm75_attach_adapter(struct i2c_adapter *adapter);
	60	static int lm75_detect(struct i2c_adapter *adapter, int address, int kind);
	61	static void lm75_init_client(struct i2c_client *client);
	62	static int lm75_detach_client(struct i2c_client *client);
	63	static int lm75_read_value(struct i2c_client *client, u8 reg);
	64	static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
	65	static struct lm75_data lm75_update_device(struct device dev);
	66
	67
	68	/* This is the driver that will be inserted */
	69	static struct i2c_driver lm75_driver = {
cdaf7934	70	.driver = {
cdaf7934 LR	71	.name = "lm75",
cdaf7934 LR	72	},
1da177e4	73	.id = I2C_DRIVERID_LM75,
1da177e4 LT	74	.attach_adapter = lm75_attach_adapter,
	75	.detach_client = lm75_detach_client,
	76	};
	77
	78	#define show(value) \
30f74292	79	static ssize_t show_##value(struct device dev, struct device_attribute attr, char *buf) \
1da177e4 LT	80	{ \
	81	struct lm75_data *data = lm75_update_device(dev); \
	82	return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
	83	}
	84	show(temp_max);
	85	show(temp_hyst);
	86	show(temp_input);
	87
	88	#define set(value, reg) \
30f74292	89	static ssize_t set_##value(struct device dev, struct device_attribute attr, const char *buf, size_t count) \
1da177e4 LT	90	{ \
	91	struct i2c_client *client = to_i2c_client(dev); \
	92	struct lm75_data *data = i2c_get_clientdata(client); \
	93	int temp = simple_strtoul(buf, NULL, 10); \
	94	\
9a61bf63	95	mutex_lock(&data->update_lock); \
1da177e4 LT	96	data->value = LM75_TEMP_TO_REG(temp); \
1da177e4 LT	97	lm75_write_value(client, reg, data->value); \
9a61bf63	98	mutex_unlock(&data->update_lock); \
1da177e4 LT	99	return count; \
	100	}
	101	set(temp_max, LM75_REG_TEMP_OS);
	102	set(temp_hyst, LM75_REG_TEMP_HYST);
	103
	104	static DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO, show_temp_max, set_temp_max);
	105	static DEVICE_ATTR(temp1_max_hyst, S_IWUSR \| S_IRUGO, show_temp_hyst, set_temp_hyst);
	106	static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL);
	107
	108	static int lm75_attach_adapter(struct i2c_adapter *adapter)
	109	{
	110	if (!(adapter->class & I2C_CLASS_HWMON))
	111	return 0;
2ed2dc3c	112	return i2c_probe(adapter, &addr_data, lm75_detect);
1da177e4 LT	113	}
1da177e4 LT	114
2ed2dc3c	115	/* This function is called by i2c_probe */
1da177e4 LT	116	static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
	117	{
	118	int i;
	119	struct i2c_client *new_client;
	120	struct lm75_data *data;
	121	int err = 0;
	122	const char *name = "";
	123
1da177e4 LT	124	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
	125	I2C_FUNC_SMBUS_WORD_DATA))
	126	goto exit;
	127
	128	/* OK. For now, we presume we have a valid client. We now create the
	129	client structure, even though we cannot fill it completely yet.
	130	But it allows us to access lm75_{read,write}_value. */
ba9c2e8d	131	if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
1da177e4 LT	132	err = -ENOMEM;
	133	goto exit;
	134	}
1da177e4 LT	135
	136	new_client = &data->client;
	137	i2c_set_clientdata(new_client, data);
	138	new_client->addr = address;
	139	new_client->adapter = adapter;
	140	new_client->driver = &lm75_driver;
	141	new_client->flags = 0;
	142
	143	/* Now, we do the remaining detection. There is no identification-
	144	dedicated register so we have to rely on several tricks:
	145	unused bits, registers cycling over 8-address boundaries,
	146	addresses 0x04-0x07 returning the last read value.
	147	The cycling+unused addresses combination is not tested,
	148	since it would significantly slow the detection down and would
	149	hardly add any value. */
	150	if (kind < 0) {
	151	int cur, conf, hyst, os;
	152
	153	/* Unused addresses */
	154	cur = i2c_smbus_read_word_data(new_client, 0);
	155	conf = i2c_smbus_read_byte_data(new_client, 1);
	156	hyst = i2c_smbus_read_word_data(new_client, 2);
	157	if (i2c_smbus_read_word_data(new_client, 4) != hyst
	158	\|\| i2c_smbus_read_word_data(new_client, 5) != hyst
	159	\|\| i2c_smbus_read_word_data(new_client, 6) != hyst
	160	\|\| i2c_smbus_read_word_data(new_client, 7) != hyst)
	161	goto exit_free;
	162	os = i2c_smbus_read_word_data(new_client, 3);
	163	if (i2c_smbus_read_word_data(new_client, 4) != os
	164	\|\| i2c_smbus_read_word_data(new_client, 5) != os
	165	\|\| i2c_smbus_read_word_data(new_client, 6) != os
	166	\|\| i2c_smbus_read_word_data(new_client, 7) != os)
	167	goto exit_free;
	168
	169	/* Unused bits */
	170	if (conf & 0xe0)
	171	goto exit_free;
	172
	173	/* Addresses cycling */
	174	for (i = 8; i < 0xff; i += 8)
	175	if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
	176	\|\| i2c_smbus_read_word_data(new_client, i + 2) != hyst
	177	\|\| i2c_smbus_read_word_data(new_client, i + 3) != os)
	178	goto exit_free;
	179	}
	180
	181	/* Determine the chip type - only one kind supported! */
	182	if (kind <= 0)
	183	kind = lm75;
	184
	185	if (kind == lm75) {
	186	name = "lm75";
	187	}
	188
	189	/* Fill in the remaining client fields and put it into the global list */
	190	strlcpy(new_client->name, name, I2C_NAME_SIZE);
	191	data->valid = 0;
9a61bf63	192	mutex_init(&data->update_lock);
1da177e4 LT	193
	194	/* Tell the I2C layer a new client has arrived */
	195	if ((err = i2c_attach_client(new_client)))
	196	goto exit_free;
	197
	198	/* Initialize the LM75 chip */
	199	lm75_init_client(new_client);
	200
	201	/* Register sysfs hooks */
943b0830 MH	202	data->class_dev = hwmon_device_register(&new_client->dev);
	203	if (IS_ERR(data->class_dev)) {
	204	err = PTR_ERR(data->class_dev);
	205	goto exit_detach;
	206	}
	207
1da177e4 LT	208	device_create_file(&new_client->dev, &dev_attr_temp1_max);
	209	device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
	210	device_create_file(&new_client->dev, &dev_attr_temp1_input);
	211
	212	return 0;
	213
943b0830 MH	214	exit_detach:
943b0830 MH	215	i2c_detach_client(new_client);
1da177e4 LT	216	exit_free:
	217	kfree(data);
	218	exit:
	219	return err;
	220	}
	221
	222	static int lm75_detach_client(struct i2c_client *client)
	223	{
943b0830 MH	224	struct lm75_data *data = i2c_get_clientdata(client);
943b0830 MH	225	hwmon_device_unregister(data->class_dev);
1da177e4	226	i2c_detach_client(client);
943b0830	227	kfree(data);
1da177e4 LT	228	return 0;
	229	}
	230
	231	/* All registers are word-sized, except for the configuration register.
	232	LM75 uses a high-byte first convention, which is exactly opposite to
	233	the usual practice. */
	234	static int lm75_read_value(struct i2c_client *client, u8 reg)
	235	{
	236	if (reg == LM75_REG_CONF)
	237	return i2c_smbus_read_byte_data(client, reg);
	238	else
	239	return swab16(i2c_smbus_read_word_data(client, reg));
	240	}
	241
	242	/* All registers are word-sized, except for the configuration register.
	243	LM75 uses a high-byte first convention, which is exactly opposite to
	244	the usual practice. */
	245	static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
	246	{
	247	if (reg == LM75_REG_CONF)
	248	return i2c_smbus_write_byte_data(client, reg, value);
	249	else
	250	return i2c_smbus_write_word_data(client, reg, swab16(value));
	251	}
	252
	253	static void lm75_init_client(struct i2c_client *client)
	254	{
e647ecf1 JD	255	int reg;
	256
	257	/* Enable if in shutdown mode */
	258	reg = lm75_read_value(client, LM75_REG_CONF);
	259	if (reg >= 0 && (reg & 0x01))
	260	lm75_write_value(client, LM75_REG_CONF, reg & 0xfe);
1da177e4 LT	261	}
	262
	263	static struct lm75_data lm75_update_device(struct device dev)
	264	{
	265	struct i2c_client *client = to_i2c_client(dev);
	266	struct lm75_data *data = i2c_get_clientdata(client);
	267
9a61bf63	268	mutex_lock(&data->update_lock);
1da177e4 LT	269
	270	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	271	\|\| !data->valid) {
	272	dev_dbg(&client->dev, "Starting lm75 update\n");
	273
	274	data->temp_input = lm75_read_value(client, LM75_REG_TEMP);
	275	data->temp_max = lm75_read_value(client, LM75_REG_TEMP_OS);
	276	data->temp_hyst = lm75_read_value(client, LM75_REG_TEMP_HYST);
	277	data->last_updated = jiffies;
	278	data->valid = 1;
	279	}
	280
9a61bf63	281	mutex_unlock(&data->update_lock);
1da177e4 LT	282
	283	return data;
	284	}
	285
	286	static int __init sensors_lm75_init(void)
	287	{
	288	return i2c_add_driver(&lm75_driver);
	289	}
	290
	291	static void __exit sensors_lm75_exit(void)
	292	{
	293	i2c_del_driver(&lm75_driver);
	294	}
	295
	296	MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
	297	MODULE_DESCRIPTION("LM75 driver");
	298	MODULE_LICENSE("GPL");
	299
	300	module_init(sensors_lm75_init);
	301	module_exit(sensors_lm75_exit);