[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 "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 semaphore	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 = {
	.owner		= THIS_MODULE,
	.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);		\
								\
	down(&data->update_lock);				\
	data->value = LM75_TEMP_TO_REG(temp);			\
	lm75_write_value(client, reg, data->value);		\
	up(&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;
	init_MUTEX(&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);

	down(&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;
	}

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