[net-next-2.6.git] / drivers / hwmon / w83l785ts.c

/*
 * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware
 *               monitoring
 * Copyright (C) 2003-2009  Jean Delvare <khali@linux-fr.org>
 *
 * Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made
 * by Winbond. It reports a single external temperature with a 1 deg
 * resolution and a 3 deg accuracy. Datasheet can be obtained from
 * Winbond's website at:
 *   http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf
 *
 * Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare
 * <khali@linux-fr.org>.
 *
 * Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read
 * error handling mechanism.
 *
 * 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/delay.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>

/* How many retries on register read error */
#define MAX_RETRIES	5

/*
 * Address to scan
 * Address is fully defined internally and cannot be changed.
 */

static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };

/*
 * The W83L785TS-S registers
 * Manufacturer ID is 0x5CA3 for Winbond.
 */

#define W83L785TS_REG_MAN_ID1		0x4D
#define W83L785TS_REG_MAN_ID2		0x4C
#define W83L785TS_REG_CHIP_ID		0x4E
#define W83L785TS_REG_CONFIG		0x40
#define W83L785TS_REG_TYPE		0x52
#define W83L785TS_REG_TEMP		0x27
#define W83L785TS_REG_TEMP_OVER		0x53 /* not sure about this one */

/*
 * Conversions
 * The W83L785TS-S uses signed 8-bit values.
 */

#define TEMP_FROM_REG(val)	((val) * 1000)

/*
 * Functions declaration
 */

static int w83l785ts_probe(struct i2c_client *client,
			   const struct i2c_device_id *id);
static int w83l785ts_detect(struct i2c_client *client,
			    struct i2c_board_info *info);
static int w83l785ts_remove(struct i2c_client *client);
static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
static struct w83l785ts_data *w83l785ts_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */
 
static const struct i2c_device_id w83l785ts_id[] = {
	{ "w83l785ts", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, w83l785ts_id);

static struct i2c_driver w83l785ts_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "w83l785ts",
	},
	.probe		= w83l785ts_probe,
	.remove		= w83l785ts_remove,
	.id_table	= w83l785ts_id,
	.detect		= w83l785ts_detect,
	.address_list	= normal_i2c,
};

/*
 * Client data (each client gets its own)
 */

struct w83l785ts_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* registers values */
	s8 temp[2]; /* 0: input
		       1: critical limit */
};

/*
 * Sysfs stuff
 */

static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
	char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct w83l785ts_data *data = w83l785ts_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);

/*
 * Real code
 */

/* Return 0 if detection is successful, -ENODEV otherwise */
static int w83l785ts_detect(struct i2c_client *client,
			    struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = client->adapter;
	u16 man_id;
	u8 chip_id;

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

	/* detection */
	if ((w83l785ts_read_value(client, W83L785TS_REG_CONFIG, 0) & 0x80)
	 || (w83l785ts_read_value(client, W83L785TS_REG_TYPE, 0) & 0xFC)) {
		dev_dbg(&adapter->dev,
			"W83L785TS-S detection failed at 0x%02x\n",
			client->addr);
		return -ENODEV;
	}

	/* Identification */
	man_id = (w83l785ts_read_value(client, W83L785TS_REG_MAN_ID1, 0) << 8)
	       + w83l785ts_read_value(client, W83L785TS_REG_MAN_ID2, 0);
	chip_id = w83l785ts_read_value(client, W83L785TS_REG_CHIP_ID, 0);

	if (man_id != 0x5CA3		/* Winbond */
	 || chip_id != 0x70) {		/* W83L785TS-S */
		dev_dbg(&adapter->dev,
			"Unsupported chip (man_id=0x%04X, chip_id=0x%02X)\n",
			man_id, chip_id);
		return -ENODEV;
	}

	strlcpy(info->type, "w83l785ts", I2C_NAME_SIZE);

	return 0;
}

static int w83l785ts_probe(struct i2c_client *new_client,
			   const struct i2c_device_id *id)
{
	struct w83l785ts_data *data;
	int err = 0;

	data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto exit;
	}

	i2c_set_clientdata(new_client, data);
	data->valid = 0;
	mutex_init(&data->update_lock);

	/* Default values in case the first read fails (unlikely). */
	data->temp[1] = data->temp[0] = 0;

	/*
	 * Initialize the W83L785TS chip
	 * Nothing yet, assume it is already started.
	 */

	err = device_create_file(&new_client->dev,
				 &sensor_dev_attr_temp1_input.dev_attr);
	if (err)
		goto exit_remove;

	err = device_create_file(&new_client->dev,
				 &sensor_dev_attr_temp1_max.dev_attr);
	if (err)
		goto exit_remove;

	/* Register sysfs hooks */
	data->hwmon_dev = hwmon_device_register(&new_client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		goto exit_remove;
	}

	return 0;

exit_remove:
	device_remove_file(&new_client->dev,
			   &sensor_dev_attr_temp1_input.dev_attr);
	device_remove_file(&new_client->dev,
			   &sensor_dev_attr_temp1_max.dev_attr);
	kfree(data);
exit:
	return err;
}

static int w83l785ts_remove(struct i2c_client *client)
{
	struct w83l785ts_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	device_remove_file(&client->dev,
			   &sensor_dev_attr_temp1_input.dev_attr);
	device_remove_file(&client->dev,
			   &sensor_dev_attr_temp1_max.dev_attr);

	kfree(data);
	return 0;
}

static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
{
	int value, i;
	struct device *dev;
	const char *prefix;

	/* We might be called during detection, at which point the client
	   isn't yet fully initialized, so we can't use dev_dbg on it */
	if (i2c_get_clientdata(client)) {
		dev = &client->dev;
		prefix = "";
	} else {
		dev = &client->adapter->dev;
		prefix = "w83l785ts: ";
	}

	/* Frequent read errors have been reported on Asus boards, so we
	 * retry on read errors. If it still fails (unlikely), return the
	 * default value requested by the caller. */
	for (i = 1; i <= MAX_RETRIES; i++) {
		value = i2c_smbus_read_byte_data(client, reg);
		if (value >= 0) {
			dev_dbg(dev, "%sRead 0x%02x from register 0x%02x.\n",
				prefix, value, reg);
			return value;
		}
		dev_dbg(dev, "%sRead failed, will retry in %d.\n", prefix, i);
		msleep(i);
	}

	dev_err(dev, "%sCouldn't read value from register 0x%02x.\n", prefix,
		reg);
	return defval;
}

static struct w83l785ts_data *w83l785ts_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct w83l785ts_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) {
		dev_dbg(&client->dev, "Updating w83l785ts data.\n");
		data->temp[0] = w83l785ts_read_value(client,
				W83L785TS_REG_TEMP, data->temp[0]);
		data->temp[1] = w83l785ts_read_value(client,
				W83L785TS_REG_TEMP_OVER, data->temp[1]);

		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

static int __init sensors_w83l785ts_init(void)
{
	return i2c_add_driver(&w83l785ts_driver);
}

static void __exit sensors_w83l785ts_exit(void)
{
	i2c_del_driver(&w83l785ts_driver);
}

MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("W83L785TS-S driver");
MODULE_LICENSE("GPL");

module_init(sensors_w83l785ts_init);
module_exit(sensors_w83l785ts_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware
	3	* monitoring
a1fa4cdc	4	* Copyright (C) 2003-2009 Jean Delvare <khali@linux-fr.org>
1da177e4 LT	5	*
	6	* Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made
	7	* by Winbond. It reports a single external temperature with a 1 deg
	8	* resolution and a 3 deg accuracy. Datasheet can be obtained from
	9	* Winbond's website at:
	10	* http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf
	11	*
	12	* Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare
	13	* <khali@linux-fr.org>.
	14	*
	15	* Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read
	16	* error handling mechanism.
	17	*
	18	* This program is free software; you can redistribute it and/or modify
	19	* it under the terms of the GNU General Public License as published by
	20	* the Free Software Foundation; either version 2 of the License, or
	21	* (at your option) any later version.
	22	*
	23	* This program is distributed in the hope that it will be useful,
	24	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	25	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	26	* GNU General Public License for more details.
	27	*
	28	* You should have received a copy of the GNU General Public License
	29	* along with this program; if not, write to the Free Software
	30	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	31	*/
	32
1da177e4 LT	33	#include <linux/module.h>
	34	#include <linux/delay.h>
	35	#include <linux/init.h>
	36	#include <linux/slab.h>
	37	#include <linux/jiffies.h>
	38	#include <linux/i2c.h>
943b0830	39	#include <linux/hwmon.h>
709439a2	40	#include <linux/hwmon-sysfs.h>
943b0830	41	#include <linux/err.h>
9a61bf63	42	#include <linux/mutex.h>
1da177e4 LT	43
	44	/* How many retries on register read error */
	45	#define MAX_RETRIES 5
	46
	47	/*
	48	* Address to scan
	49	* Address is fully defined internally and cannot be changed.
	50	*/
	51
25e9c86d	52	static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };
1da177e4	53
1da177e4 LT	54	/*
	55	* The W83L785TS-S registers
	56	* Manufacturer ID is 0x5CA3 for Winbond.
	57	*/
	58
	59	#define W83L785TS_REG_MAN_ID1 0x4D
	60	#define W83L785TS_REG_MAN_ID2 0x4C
	61	#define W83L785TS_REG_CHIP_ID 0x4E
	62	#define W83L785TS_REG_CONFIG 0x40
	63	#define W83L785TS_REG_TYPE 0x52
	64	#define W83L785TS_REG_TEMP 0x27
	65	#define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */
	66
	67	/*
	68	* Conversions
	69	* The W83L785TS-S uses signed 8-bit values.
	70	*/
	71
cb929eae	72	#define TEMP_FROM_REG(val) ((val) * 1000)
1da177e4 LT	73
	74	/*
	75	* Functions declaration
	76	*/
	77
dc18a418 JD	78	static int w83l785ts_probe(struct i2c_client *client,
dc18a418 JD	79	const struct i2c_device_id *id);
310ec792	80	static int w83l785ts_detect(struct i2c_client *client,
dc18a418 JD	81	struct i2c_board_info *info);
dc18a418 JD	82	static int w83l785ts_remove(struct i2c_client *client);
1da177e4 LT	83	static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
	84	static struct w83l785ts_data w83l785ts_update_device(struct device dev);
	85
	86	/*
	87	* Driver data (common to all clients)
	88	*/
	89
dc18a418	90	static const struct i2c_device_id w83l785ts_id[] = {
1f86df49	91	{ "w83l785ts", 0 },
dc18a418 JD	92	{ }
	93	};
	94	MODULE_DEVICE_TABLE(i2c, w83l785ts_id);
	95
1da177e4	96	static struct i2c_driver w83l785ts_driver = {
dc18a418	97	.class = I2C_CLASS_HWMON,
cdaf7934	98	.driver = {
cdaf7934 LR	99	.name = "w83l785ts",
cdaf7934 LR	100	},
dc18a418 JD	101	.probe = w83l785ts_probe,
	102	.remove = w83l785ts_remove,
	103	.id_table = w83l785ts_id,
	104	.detect = w83l785ts_detect,
c3813d6a	105	.address_list = normal_i2c,
1da177e4 LT	106	};
	107
	108	/*
	109	* Client data (each client gets its own)
	110	*/
	111
	112	struct w83l785ts_data {
1beeffe4	113	struct device *hwmon_dev;
9a61bf63	114	struct mutex update_lock;
1da177e4 LT	115	char valid; /* zero until following fields are valid */
	116	unsigned long last_updated; /* in jiffies */
	117
	118	/* registers values */
cb929eae	119	s8 temp[2]; /* 0: input
709439a2	120	1: critical limit */
1da177e4 LT	121	};
	122
	123	/*
	124	* Sysfs stuff
	125	*/
	126
709439a2 JD	127	static ssize_t show_temp(struct device dev, struct device_attribute devattr,
709439a2 JD	128	char *buf)
1da177e4	129	{
709439a2	130	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
1da177e4	131	struct w83l785ts_data *data = w83l785ts_update_device(dev);
709439a2	132	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
1da177e4 LT	133	}
1da177e4 LT	134
709439a2 JD	135	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
709439a2 JD	136	static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);
1da177e4 LT	137
	138	/*
	139	* Real code
	140	*/
	141
dc18a418	142	/* Return 0 if detection is successful, -ENODEV otherwise */
310ec792	143	static int w83l785ts_detect(struct i2c_client *client,
dc18a418	144	struct i2c_board_info *info)
1da177e4	145	{
a1fa4cdc JD	146	struct i2c_adapter *adapter = client->adapter;
	147	u16 man_id;
	148	u8 chip_id;
1da177e4 LT	149
1da177e4 LT	150	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
dc18a418	151	return -ENODEV;
1da177e4	152
a1fa4cdc JD	153	/* detection */
	154	if ((w83l785ts_read_value(client, W83L785TS_REG_CONFIG, 0) & 0x80)
	155	\|\| (w83l785ts_read_value(client, W83L785TS_REG_TYPE, 0) & 0xFC)) {
	156	dev_dbg(&adapter->dev,
	157	"W83L785TS-S detection failed at 0x%02x\n",
	158	client->addr);
	159	return -ENODEV;
1da177e4 LT	160	}
1da177e4 LT	161
a1fa4cdc JD	162	/* Identification */
	163	man_id = (w83l785ts_read_value(client, W83L785TS_REG_MAN_ID1, 0) << 8)
	164	+ w83l785ts_read_value(client, W83L785TS_REG_MAN_ID2, 0);
	165	chip_id = w83l785ts_read_value(client, W83L785TS_REG_CHIP_ID, 0);
	166
	167	if (man_id != 0x5CA3 /* Winbond */
	168	\|\| chip_id != 0x70) { /* W83L785TS-S */
	169	dev_dbg(&adapter->dev,
	170	"Unsupported chip (man_id=0x%04X, chip_id=0x%02X)\n",
	171	man_id, chip_id);
	172	return -ENODEV;
1da177e4 LT	173	}
1da177e4 LT	174
dc18a418 JD	175	strlcpy(info->type, "w83l785ts", I2C_NAME_SIZE);
	176
	177	return 0;
	178	}
	179
	180	static int w83l785ts_probe(struct i2c_client *new_client,
	181	const struct i2c_device_id *id)
	182	{
	183	struct w83l785ts_data *data;
	184	int err = 0;
	185
	186	data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL);
	187	if (!data) {
	188	err = -ENOMEM;
	189	goto exit;
	190	}
	191
	192	i2c_set_clientdata(new_client, data);
1da177e4	193	data->valid = 0;
9a61bf63	194	mutex_init(&data->update_lock);
1da177e4 LT	195
1da177e4 LT	196	/* Default values in case the first read fails (unlikely). */
709439a2	197	data->temp[1] = data->temp[0] = 0;
1da177e4	198
1da177e4 LT	199	/*
	200	* Initialize the W83L785TS chip
	201	* Nothing yet, assume it is already started.
	202	*/
	203
ccc5c306 RM	204	err = device_create_file(&new_client->dev,
	205	&sensor_dev_attr_temp1_input.dev_attr);
	206	if (err)
	207	goto exit_remove;
	208
	209	err = device_create_file(&new_client->dev,
	210	&sensor_dev_attr_temp1_max.dev_attr);
	211	if (err)
	212	goto exit_remove;
	213
1da177e4	214	/* Register sysfs hooks */
1beeffe4 TJ	215	data->hwmon_dev = hwmon_device_register(&new_client->dev);
	216	if (IS_ERR(data->hwmon_dev)) {
	217	err = PTR_ERR(data->hwmon_dev);
ccc5c306	218	goto exit_remove;
943b0830 MH	219	}
943b0830 MH	220
1da177e4 LT	221	return 0;
1da177e4 LT	222
ccc5c306 RM	223	exit_remove:
	224	device_remove_file(&new_client->dev,
	225	&sensor_dev_attr_temp1_input.dev_attr);
	226	device_remove_file(&new_client->dev,
	227	&sensor_dev_attr_temp1_max.dev_attr);
1da177e4 LT	228	kfree(data);
	229	exit:
	230	return err;
	231	}
	232
dc18a418	233	static int w83l785ts_remove(struct i2c_client *client)
1da177e4	234	{
943b0830	235	struct w83l785ts_data *data = i2c_get_clientdata(client);
1da177e4	236
1beeffe4	237	hwmon_device_unregister(data->hwmon_dev);
ccc5c306 RM	238	device_remove_file(&client->dev,
	239	&sensor_dev_attr_temp1_input.dev_attr);
	240	device_remove_file(&client->dev,
	241	&sensor_dev_attr_temp1_max.dev_attr);
1da177e4	242
943b0830	243	kfree(data);
1da177e4 LT	244	return 0;
	245	}
	246
	247	static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
	248	{
	249	int value, i;
dc18a418 JD	250	struct device *dev;
	251	const char *prefix;
	252
	253	/* We might be called during detection, at which point the client
	254	isn't yet fully initialized, so we can't use dev_dbg on it */
	255	if (i2c_get_clientdata(client)) {
	256	dev = &client->dev;
	257	prefix = "";
	258	} else {
	259	dev = &client->adapter->dev;
	260	prefix = "w83l785ts: ";
	261	}
1da177e4 LT	262
	263	/* Frequent read errors have been reported on Asus boards, so we
	264	* retry on read errors. If it still fails (unlikely), return the
	265	* default value requested by the caller. */
	266	for (i = 1; i <= MAX_RETRIES; i++) {
	267	value = i2c_smbus_read_byte_data(client, reg);
	268	if (value >= 0) {
dc18a418 JD	269	dev_dbg(dev, "%sRead 0x%02x from register 0x%02x.\n",
dc18a418 JD	270	prefix, value, reg);
1da177e4 LT	271	return value;
1da177e4 LT	272	}
dc18a418	273	dev_dbg(dev, "%sRead failed, will retry in %d.\n", prefix, i);
1da177e4 LT	274	msleep(i);
	275	}
	276
dc18a418	277	dev_err(dev, "%sCouldn't read value from register 0x%02x.\n", prefix,
4040c415	278	reg);
1da177e4 LT	279	return defval;
	280	}
	281
	282	static struct w83l785ts_data w83l785ts_update_device(struct device dev)
	283	{
	284	struct i2c_client *client = to_i2c_client(dev);
	285	struct w83l785ts_data *data = i2c_get_clientdata(client);
	286
9a61bf63	287	mutex_lock(&data->update_lock);
1da177e4 LT	288
	289	if (!data->valid \|\| time_after(jiffies, data->last_updated + HZ * 2)) {
	290	dev_dbg(&client->dev, "Updating w83l785ts data.\n");
709439a2 JD	291	data->temp[0] = w83l785ts_read_value(client,
	292	W83L785TS_REG_TEMP, data->temp[0]);
	293	data->temp[1] = w83l785ts_read_value(client,
	294	W83L785TS_REG_TEMP_OVER, data->temp[1]);
1da177e4 LT	295
	296	data->last_updated = jiffies;
	297	data->valid = 1;
	298	}
	299
9a61bf63	300	mutex_unlock(&data->update_lock);
1da177e4 LT	301
	302	return data;
	303	}
	304
	305	static int __init sensors_w83l785ts_init(void)
	306	{
	307	return i2c_add_driver(&w83l785ts_driver);
	308	}
	309
	310	static void __exit sensors_w83l785ts_exit(void)
	311	{
	312	i2c_del_driver(&w83l785ts_driver);
	313	}
	314
	315	MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
	316	MODULE_DESCRIPTION("W83L785TS-S driver");
	317	MODULE_LICENSE("GPL");
	318
	319	module_init(sensors_w83l785ts_init);
	320	module_exit(sensors_w83l785ts_exit);