[mirror_ubuntu-jammy-kernel.git] / drivers / hwmon / ds1621.c

/*
 * ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
 *	      monitoring
 * Christian W. Zuckschwerdt  <zany@triq.net>  2000-11-23
 * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
 * the help of Jean Delvare <khali@linux-fr.org>
 *
 * The DS1621 device is a digital temperature/thermometer with 9-bit
 * resolution, a thermal alarm output (Tout), and user-defined minimum
 * and maximum temperature thresholds (TH and TL).
 *
 * The DS1625 and DS1721 are pin compatible with the DS1621 and similar
 * in operation, with slight variations as noted in the device
 * datasheets (please refer to www.maximintegrated.com for specific
 * device information).
 *
 * Since the DS1621 was the first chipset supported by this driver,
 * most comments will refer to this chipset, but are actually general
 * and concern all supported chipsets, unless mentioned otherwise.
 *
 * 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 <linux/sysfs.h>
#include <linux/kernel.h>

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

/* Supported devices */
enum chips { ds1621, ds1625, ds1721 };

/* Insmod parameters */
static int polarity = -1;
module_param(polarity, int, 0);
MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");

/*
 * The Configuration/Status register
 *
 * - DS1621:
 *   7    6    5    4    3    2    1    0
 * |Done|THF |TLF |NVB | X  | X  |POL |1SHOT|
 *
 * - DS1625:
 *   7    6    5    4    3    2    1    0
 * |Done|THF |TLF |NVB | 1  | 0  |POL |1SHOT|
 *
 * - DS1721:
 *   7    6    5    4    3    2    1    0
 * |Done| X  | X  | U  | R1 | R0 |POL |1SHOT|
 *
 * Where:
 * - 'X' is Reserved
 * - 'U' is Undefined
 */
#define DS1621_REG_CONFIG_NVB		0x10
#define DS1621_REG_CONFIG_RESOL		0x0C
#define DS1621_REG_CONFIG_POLARITY	0x02
#define DS1621_REG_CONFIG_1SHOT		0x01
#define DS1621_REG_CONFIG_DONE		0x80

#define DS1621_REG_CONFIG_RESOL_SHIFT	2

/* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */
static const unsigned short ds1721_convrates[] = {
	94,	/*  9-bits (0.5,  93.75, RES[0..1] = 0 */
	188,	/* 10-bits (0.25, 187.5, RES[0..1] = 1 */
	375,	/* 11-bits (0.125,  375, RES[0..1] = 2 */
	750,	/* 12-bits (0.0625, 750, RES[0..1] = 3 */
};

#define DS1621_CONVERSION_MAX	750
#define DS1625_CONVERSION_MAX	500

#define DS1621_TEMP_MAX	125000
#define DS1621_TEMP_MIN	(-55000)

/* The DS1621 temperature registers */
static const u8 DS1621_REG_TEMP[3] = {
	0xAA,		/* input, word, RO */
	0xA2,		/* min, word, RW */
	0xA1,		/* max, word, RW */
};
#define DS1621_REG_CONF			0xAC /* byte, RW */
#define DS1621_COM_START		0xEE /* no data */
#define DS1721_COM_START		0x51 /* no data */
#define DS1621_COM_STOP			0x22 /* no data */

/* The DS1621 configuration register */
#define DS1621_ALARM_TEMP_HIGH		0x40
#define DS1621_ALARM_TEMP_LOW		0x20

/* Conversions */
#define ALARMS_FROM_REG(val) ((val) & \
			(DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))

/* Each client has this additional data */
struct ds1621_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid;			/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */
	enum chips kind;		/* device type */

	u16 temp[3];			/* Register values, word */
	u8 conf;			/* Register encoding, combined */
	u16 update_interval;		/* Conversion rate in milliseconds */
};

static inline int DS1621_TEMP_FROM_REG(u16 reg)
{
	return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10);
}

/*
 * TEMP: 0.001C/bit (-55C to +125C)
 * REG:
 *  - 1621, 1625: x = 0.5C
 *  - 1721:       x = 0.0625C
 * Assume highest resolution and let the bits fall where they may..
 */
static inline u16 DS1621_TEMP_TO_REG(long temp)
{
	int ntemp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX);
	ntemp += (ntemp < 0 ? -31 : 31);
	ntemp = DIV_ROUND_CLOSEST(ntemp * 10, 625) << 4;
	return (u16)ntemp;
}

static void ds1621_init_client(struct i2c_client *client)
{
	u8 conf, new_conf, sreg, resol;
	struct ds1621_data *data = i2c_get_clientdata(client);

	new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
	/* switch to continuous conversion mode */
	new_conf &= ~DS1621_REG_CONFIG_1SHOT;

	/* setup output polarity */
	if (polarity == 0)
		new_conf &= ~DS1621_REG_CONFIG_POLARITY;
	else if (polarity == 1)
		new_conf |= DS1621_REG_CONFIG_POLARITY;

	if (conf != new_conf)
		i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf);

	switch (data->kind) {
	case ds1625:
		data->update_interval = DS1625_CONVERSION_MAX;
		sreg = DS1621_COM_START;
		break;
	case ds1721:
		resol = (new_conf & DS1621_REG_CONFIG_RESOL) >>
			 DS1621_REG_CONFIG_RESOL_SHIFT;
		data->update_interval = ds1721_convrates[resol];
		sreg = DS1721_COM_START;
		break;
	default:
		data->update_interval = DS1621_CONVERSION_MAX;
		sreg = DS1621_COM_START;
		break;
	}

	/* start conversion */
	i2c_smbus_write_byte(client, sreg);
}

static struct ds1621_data *ds1621_update_client(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ds1621_data *data = i2c_get_clientdata(client);
	u8 new_conf;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + data->update_interval) ||
	    !data->valid) {
		int i;

		dev_dbg(&client->dev, "Starting ds1621 update\n");

		data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);

		for (i = 0; i < ARRAY_SIZE(data->temp); i++)
			data->temp[i] = i2c_smbus_read_word_swapped(client,
							 DS1621_REG_TEMP[i]);

		/* reset alarms if necessary */
		new_conf = data->conf;
		if (data->temp[0] > data->temp[1])	/* input > min */
			new_conf &= ~DS1621_ALARM_TEMP_LOW;
		if (data->temp[0] < data->temp[2])	/* input < max */
			new_conf &= ~DS1621_ALARM_TEMP_HIGH;
		if (data->conf != new_conf)
			i2c_smbus_write_byte_data(client, DS1621_REG_CONF,
						  new_conf);

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

	mutex_unlock(&data->update_lock);

	return data;
}

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 ds1621_data *data = ds1621_update_client(dev);
	return sprintf(buf, "%d\n",
		       DS1621_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 ds1621_data *data = i2c_get_clientdata(client);
	long val;
	int err;

	err = kstrtol(buf, 10, &val);
	if (err)
		return err;

	mutex_lock(&data->update_lock);
	data->temp[attr->index] = DS1621_TEMP_TO_REG(val);
	i2c_smbus_write_word_swapped(client, DS1621_REG_TEMP[attr->index],
				     data->temp[attr->index]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
			   char *buf)
{
	struct ds1621_data *data = ds1621_update_client(dev);
	return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
			  char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ds1621_data *data = ds1621_update_client(dev);
	return sprintf(buf, "%d\n", !!(data->conf & attr->index));
}

static ssize_t show_convrate(struct device *dev, struct device_attribute *da,
			  char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ds1621_data *data = i2c_get_clientdata(client);
	return scnprintf(buf, PAGE_SIZE, "%hu\n", data->update_interval);
}

static ssize_t set_convrate(struct device *dev, struct device_attribute *da,
			    const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ds1621_data *data = i2c_get_clientdata(client);
	unsigned long convrate;
	s32 err;
	int resol = 0;

	err = kstrtoul(buf, 10, &convrate);
	if (err)
		return err;

	/* Convert rate into resolution bits */
	while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) &&
	       convrate > ds1721_convrates[resol])
		resol++;

	mutex_lock(&data->update_lock);
	data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
	data->conf &= ~DS1621_REG_CONFIG_RESOL;
	data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT);
	i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf);
	data->update_interval = ds1721_convrates[resol];
	mutex_unlock(&data->update_lock);

	return count;
}

static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_convrate,
		   set_convrate);

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
		DS1621_ALARM_TEMP_LOW);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
		DS1621_ALARM_TEMP_HIGH);

static struct attribute *ds1621_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&dev_attr_alarms.attr,
	&dev_attr_update_interval.attr,
	NULL
};

static umode_t ds1621_attribute_visible(struct kobject *kobj,
					struct attribute *attr, int index)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct i2c_client *client = to_i2c_client(dev);
	struct ds1621_data *data = i2c_get_clientdata(client);

	if (attr == &dev_attr_update_interval.attr)
		if (data->kind != ds1721)
			/* shhh, we're hiding update_interval */
			return 0;
	return attr->mode;
}

static const struct attribute_group ds1621_group = {
	.attrs = ds1621_attributes,
	.is_visible = ds1621_attribute_visible
};


/* Return 0 if detection is successful, -ENODEV otherwise */
static int ds1621_detect(struct i2c_client *client,
			 struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = client->adapter;
	int conf, temp;
	int i;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
				     | I2C_FUNC_SMBUS_WORD_DATA
				     | I2C_FUNC_SMBUS_WRITE_BYTE))
		return -ENODEV;

	/*
	 * Now, we do the remaining detection. It is lousy.
	 *
	 * The NVB bit should be low if no EEPROM write has been requested
	 * during the latest 10ms, which is highly improbable in our case.
	 */
	conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
	if (conf < 0 || conf & DS1621_REG_CONFIG_NVB)
		return -ENODEV;
	/* The 7 lowest bits of a temperature should always be 0. */
	for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) {
		temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]);
		if (temp < 0 || (temp & 0x7f00))
			return -ENODEV;
	}

	strlcpy(info->type, "ds1621", I2C_NAME_SIZE);

	return 0;
}

static int ds1621_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct ds1621_data *data;
	int err;

	data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data),
			    GFP_KERNEL);
	if (!data)
		return -ENOMEM;

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

	data->kind = id->driver_data;

	/* Initialize the DS1621 chip */
	ds1621_init_client(client);

	/* Register sysfs hooks */
	err = sysfs_create_group(&client->dev.kobj, &ds1621_group);
	if (err)
		return err;

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

	return 0;

 exit_remove_files:
	sysfs_remove_group(&client->dev.kobj, &ds1621_group);
	return err;
}

static int ds1621_remove(struct i2c_client *client)
{
	struct ds1621_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &ds1621_group);

	return 0;
}

static const struct i2c_device_id ds1621_id[] = {
	{ "ds1621", ds1621 },
	{ "ds1625", ds1625 },
	{ "ds1721", ds1721 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ds1621_id);

/* This is the driver that will be inserted */
static struct i2c_driver ds1621_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "ds1621",
	},
	.probe		= ds1621_probe,
	.remove		= ds1621_remove,
	.id_table	= ds1621_id,
	.detect		= ds1621_detect,
	.address_list	= normal_i2c,
};

module_i2c_driver(ds1621_driver);

MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
MODULE_DESCRIPTION("DS1621 driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4	1	/*
19f2c059 GR	2	* ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
	3	* monitoring
	4	* Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23
	5	* based on lm75.c by Frodo Looijaard <frodol@dds.nl>
	6	* Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
	7	* the help of Jean Delvare <khali@linux-fr.org>
	8	*
cd6c8a42 RC	9	* The DS1621 device is a digital temperature/thermometer with 9-bit
	10	* resolution, a thermal alarm output (Tout), and user-defined minimum
	11	* and maximum temperature thresholds (TH and TL).
	12	*
	13	* The DS1625 and DS1721 are pin compatible with the DS1621 and similar
	14	* in operation, with slight variations as noted in the device
	15	* datasheets (please refer to www.maximintegrated.com for specific
	16	* device information).
	17	*
	18	* Since the DS1621 was the first chipset supported by this driver,
	19	* most comments will refer to this chipset, but are actually general
	20	* and concern all supported chipsets, unless mentioned otherwise.
	21	*
19f2c059 GR	22	* This program is free software; you can redistribute it and/or modify
	23	* it under the terms of the GNU General Public License as published by
	24	* the Free Software Foundation; either version 2 of the License, or
	25	* (at your option) any later version.
	26	*
	27	* This program is distributed in the hope that it will be useful,
	28	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	29	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	30	* GNU General Public License for more details.
	31	*
	32	* You should have received a copy of the GNU General Public License
	33	* along with this program; if not, write to the Free Software
	34	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	35	*/
1da177e4 LT	36
	37	#include <linux/module.h>
	38	#include <linux/init.h>
	39	#include <linux/slab.h>
	40	#include <linux/jiffies.h>
	41	#include <linux/i2c.h>
943b0830	42	#include <linux/hwmon.h>
46a2e71c	43	#include <linux/hwmon-sysfs.h>
943b0830	44	#include <linux/err.h>
9a61bf63	45	#include <linux/mutex.h>
a5ebe668	46	#include <linux/sysfs.h>
cd6c8a42	47	#include <linux/kernel.h>
1da177e4 LT	48
1da177e4 LT	49	/* Addresses to scan */
25e9c86d	50	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
1da177e4	51	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
1da177e4	52
cd6c8a42 RC	53	/* Supported devices */
	54	enum chips { ds1621, ds1625, ds1721 };
	55
1da177e4	56	/* Insmod parameters */
1da177e4 LT	57	static int polarity = -1;
	58	module_param(polarity, int, 0);
	59	MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
	60
cd6c8a42 RC	61	/*
	62	* The Configuration/Status register
	63	*
	64	* - DS1621:
	65	* 7 6 5 4 3 2 1 0
	66	* \|Done\|THF \|TLF \|NVB \| X \| X \|POL \|1SHOT\|
	67	*
	68	* - DS1625:
	69	* 7 6 5 4 3 2 1 0
	70	* \|Done\|THF \|TLF \|NVB \| 1 \| 0 \|POL \|1SHOT\|
	71	*
	72	* - DS1721:
	73	* 7 6 5 4 3 2 1 0
	74	* \|Done\| X \| X \| U \| R1 \| R0 \|POL \|1SHOT\|
	75	*
	76	* Where:
	77	* - 'X' is Reserved
	78	* - 'U' is Undefined
	79	*/
1da177e4	80	#define DS1621_REG_CONFIG_NVB 0x10
cd6c8a42	81	#define DS1621_REG_CONFIG_RESOL 0x0C
1da177e4 LT	82	#define DS1621_REG_CONFIG_POLARITY 0x02
	83	#define DS1621_REG_CONFIG_1SHOT 0x01
	84	#define DS1621_REG_CONFIG_DONE 0x80
	85
cd6c8a42 RC	86	#define DS1621_REG_CONFIG_RESOL_SHIFT 2
	87
	88	/* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */
	89	static const unsigned short ds1721_convrates[] = {
	90	94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */
	91	188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */
	92	375, /* 11-bits (0.125, 375, RES[0..1] = 2 */
	93	750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */
	94	};
	95
	96	#define DS1621_CONVERSION_MAX 750
	97	#define DS1625_CONVERSION_MAX 500
	98
	99	#define DS1621_TEMP_MAX 125000
	100	#define DS1621_TEMP_MIN (-55000)
	101
	102	/* The DS1621 temperature registers */
46a2e71c JD	103	static const u8 DS1621_REG_TEMP[3] = {
	104	0xAA, /* input, word, RO */
	105	0xA2, /* min, word, RW */
	106	0xA1, /* max, word, RW */
	107	};
1da177e4 LT	108	#define DS1621_REG_CONF 0xAC /* byte, RW */
1da177e4 LT	109	#define DS1621_COM_START 0xEE /* no data */
cd6c8a42	110	#define DS1721_COM_START 0x51 /* no data */
1da177e4 LT	111	#define DS1621_COM_STOP 0x22 /* no data */
	112
	113	/* The DS1621 configuration register */
	114	#define DS1621_ALARM_TEMP_HIGH 0x40
	115	#define DS1621_ALARM_TEMP_LOW 0x20
	116
75819f01	117	/* Conversions */
1da177e4	118	#define ALARMS_FROM_REG(val) ((val) & \
19f2c059	119	(DS1621_ALARM_TEMP_HIGH \| DS1621_ALARM_TEMP_LOW))
1da177e4 LT	120
	121	/* Each client has this additional data */
	122	struct ds1621_data {
1beeffe4	123	struct device *hwmon_dev;
9a61bf63	124	struct mutex update_lock;
1da177e4 LT	125	char valid; /* !=0 if following fields are valid */
1da177e4 LT	126	unsigned long last_updated; /* In jiffies */
cd6c8a42	127	enum chips kind; /* device type */
1da177e4	128
46a2e71c	129	u16 temp[3]; /* Register values, word */
1da177e4	130	u8 conf; /* Register encoding, combined */
cd6c8a42	131	u16 update_interval; /* Conversion rate in milliseconds */
1da177e4 LT	132	};
1da177e4 LT	133
cd6c8a42 RC	134	static inline int DS1621_TEMP_FROM_REG(u16 reg)
	135	{
	136	return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10);
	137	}
	138
	139	/*
	140	* TEMP: 0.001C/bit (-55C to +125C)
	141	* REG:
	142	* - 1621, 1625: x = 0.5C
	143	* - 1721: x = 0.0625C
	144	* Assume highest resolution and let the bits fall where they may..
	145	*/
	146	static inline u16 DS1621_TEMP_TO_REG(long temp)
	147	{
	148	int ntemp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX);
	149	ntemp += (ntemp < 0 ? -31 : 31);
	150	ntemp = DIV_ROUND_CLOSEST(ntemp * 10, 625) << 4;
	151	return (u16)ntemp;
	152	}
	153
1da177e4 LT	154	static void ds1621_init_client(struct i2c_client *client)
1da177e4 LT	155	{
cd6c8a42 RC	156	u8 conf, new_conf, sreg, resol;
cd6c8a42 RC	157	struct ds1621_data *data = i2c_get_clientdata(client);
e4879e28 JD	158
e4879e28 JD	159	new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
44bbe87e	160	/* switch to continuous conversion mode */
e4879e28	161	new_conf &= ~DS1621_REG_CONFIG_1SHOT;
1da177e4 LT	162
	163	/* setup output polarity */
	164	if (polarity == 0)
e4879e28	165	new_conf &= ~DS1621_REG_CONFIG_POLARITY;
1da177e4	166	else if (polarity == 1)
e4879e28	167	new_conf \|= DS1621_REG_CONFIG_POLARITY;
19f2c059	168
e4879e28 JD	169	if (conf != new_conf)
e4879e28 JD	170	i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf);
19f2c059	171
cd6c8a42 RC	172	switch (data->kind) {
	173	case ds1625:
	174	data->update_interval = DS1625_CONVERSION_MAX;
	175	sreg = DS1621_COM_START;
	176	break;
	177	case ds1721:
	178	resol = (new_conf & DS1621_REG_CONFIG_RESOL) >>
	179	DS1621_REG_CONFIG_RESOL_SHIFT;
	180	data->update_interval = ds1721_convrates[resol];
	181	sreg = DS1721_COM_START;
	182	break;
	183	default:
	184	data->update_interval = DS1621_CONVERSION_MAX;
	185	sreg = DS1621_COM_START;
	186	break;
	187	}
	188
1da177e4	189	/* start conversion */
cd6c8a42	190	i2c_smbus_write_byte(client, sreg);
1da177e4 LT	191	}
1da177e4 LT	192
9202add6 JD	193	static struct ds1621_data ds1621_update_client(struct device dev)
	194	{
	195	struct i2c_client *client = to_i2c_client(dev);
	196	struct ds1621_data *data = i2c_get_clientdata(client);
	197	u8 new_conf;
	198
	199	mutex_lock(&data->update_lock);
	200
cd6c8a42 RC	201	if (time_after(jiffies, data->last_updated + data->update_interval) \|\|
cd6c8a42 RC	202	!data->valid) {
9202add6 JD	203	int i;
	204
	205	dev_dbg(&client->dev, "Starting ds1621 update\n");
	206
594592dc	207	data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
9202add6 JD	208
9202add6 JD	209	for (i = 0; i < ARRAY_SIZE(data->temp); i++)
90f4102c	210	data->temp[i] = i2c_smbus_read_word_swapped(client,
594592dc	211	DS1621_REG_TEMP[i]);
9202add6 JD	212
	213	/* reset alarms if necessary */
	214	new_conf = data->conf;
	215	if (data->temp[0] > data->temp[1]) /* input > min */
	216	new_conf &= ~DS1621_ALARM_TEMP_LOW;
	217	if (data->temp[0] < data->temp[2]) /* input < max */
	218	new_conf &= ~DS1621_ALARM_TEMP_HIGH;
	219	if (data->conf != new_conf)
594592dc JD	220	i2c_smbus_write_byte_data(client, DS1621_REG_CONF,
594592dc JD	221	new_conf);
9202add6 JD	222
	223	data->last_updated = jiffies;
	224	data->valid = 1;
	225	}
	226
	227	mutex_unlock(&data->update_lock);
	228
	229	return data;
	230	}
	231
46a2e71c JD	232	static ssize_t show_temp(struct device dev, struct device_attribute da,
	233	char *buf)
	234	{
	235	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	236	struct ds1621_data *data = ds1621_update_client(dev);
	237	return sprintf(buf, "%d\n",
cd6c8a42	238	DS1621_TEMP_FROM_REG(data->temp[attr->index]));
1da177e4 LT	239	}
1da177e4 LT	240
46a2e71c JD	241	static ssize_t set_temp(struct device dev, struct device_attribute da,
	242	const char *buf, size_t count)
	243	{
	244	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	245	struct i2c_client *client = to_i2c_client(dev);
e4879e28	246	struct ds1621_data *data = i2c_get_clientdata(client);
19f2c059 GR	247	long val;
	248	int err;
	249
	250	err = kstrtol(buf, 10, &val);
	251	if (err)
	252	return err;
1da177e4	253
46a2e71c	254	mutex_lock(&data->update_lock);
cd6c8a42	255	data->temp[attr->index] = DS1621_TEMP_TO_REG(val);
90f4102c JD	256	i2c_smbus_write_word_swapped(client, DS1621_REG_TEMP[attr->index],
90f4102c JD	257	data->temp[attr->index]);
46a2e71c JD	258	mutex_unlock(&data->update_lock);
	259	return count;
	260	}
1da177e4	261
46a2e71c JD	262	static ssize_t show_alarms(struct device dev, struct device_attribute da,
46a2e71c JD	263	char *buf)
1da177e4 LT	264	{
	265	struct ds1621_data *data = ds1621_update_client(dev);
	266	return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
	267	}
	268
87f0f31b JD	269	static ssize_t show_alarm(struct device dev, struct device_attribute da,
	270	char *buf)
	271	{
	272	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	273	struct ds1621_data *data = ds1621_update_client(dev);
	274	return sprintf(buf, "%d\n", !!(data->conf & attr->index));
	275	}
	276
3a8fe331 RC	277	static ssize_t show_convrate(struct device dev, struct device_attribute da,
	278	char *buf)
	279	{
	280	struct i2c_client *client = to_i2c_client(dev);
	281	struct ds1621_data *data = i2c_get_clientdata(client);
	282	return scnprintf(buf, PAGE_SIZE, "%hu\n", data->update_interval);
	283	}
	284
	285	static ssize_t set_convrate(struct device dev, struct device_attribute da,
	286	const char *buf, size_t count)
	287	{
	288	struct i2c_client *client = to_i2c_client(dev);
	289	struct ds1621_data *data = i2c_get_clientdata(client);
	290	unsigned long convrate;
	291	s32 err;
	292	int resol = 0;
	293
	294	err = kstrtoul(buf, 10, &convrate);
	295	if (err)
	296	return err;
	297
	298	/* Convert rate into resolution bits */
	299	while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) &&
	300	convrate > ds1721_convrates[resol])
	301	resol++;
	302
	303	mutex_lock(&data->update_lock);
	304	data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
	305	data->conf &= ~DS1621_REG_CONFIG_RESOL;
	306	data->conf \|= (resol << DS1621_REG_CONFIG_RESOL_SHIFT);
	307	i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf);
	308	data->update_interval = ds1721_convrates[resol];
	309	mutex_unlock(&data->update_lock);
	310
	311	return count;
	312	}
	313
1da177e4	314	static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
3a8fe331 RC	315	static DEVICE_ATTR(update_interval, S_IWUSR \| S_IRUGO, show_convrate,
	316	set_convrate);
	317
46a2e71c JD	318	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
	319	static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO, show_temp, set_temp, 1);
	320	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO, show_temp, set_temp, 2);
87f0f31b JD	321	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
	322	DS1621_ALARM_TEMP_LOW);
	323	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
	324	DS1621_ALARM_TEMP_HIGH);
1da177e4	325
a5ebe668	326	static struct attribute *ds1621_attributes[] = {
46a2e71c JD	327	&sensor_dev_attr_temp1_input.dev_attr.attr,
	328	&sensor_dev_attr_temp1_min.dev_attr.attr,
	329	&sensor_dev_attr_temp1_max.dev_attr.attr,
87f0f31b JD	330	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
87f0f31b JD	331	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
a5ebe668	332	&dev_attr_alarms.attr,
3a8fe331	333	&dev_attr_update_interval.attr,
a5ebe668 JD	334	NULL
	335	};
	336
3a8fe331 RC	337	static umode_t ds1621_attribute_visible(struct kobject *kobj,
	338	struct attribute *attr, int index)
	339	{
	340	struct device *dev = container_of(kobj, struct device, kobj);
	341	struct i2c_client *client = to_i2c_client(dev);
	342	struct ds1621_data *data = i2c_get_clientdata(client);
	343
	344	if (attr == &dev_attr_update_interval.attr)
	345	if (data->kind != ds1721)
	346	/* shhh, we're hiding update_interval */
	347	return 0;
	348	return attr->mode;
	349	}
	350
a5ebe668 JD	351	static const struct attribute_group ds1621_group = {
a5ebe668 JD	352	.attrs = ds1621_attributes,
3a8fe331	353	.is_visible = ds1621_attribute_visible
a5ebe668 JD	354	};
a5ebe668 JD	355
1da177e4	356
70313eab	357	/* Return 0 if detection is successful, -ENODEV otherwise */
310ec792	358	static int ds1621_detect(struct i2c_client *client,
70313eab	359	struct i2c_board_info *info)
1da177e4	360	{
70313eab	361	struct i2c_adapter *adapter = client->adapter;
1da177e4	362	int conf, temp;
70313eab	363	int i;
1da177e4	364
19f2c059 GR	365	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
19f2c059 GR	366	\| I2C_FUNC_SMBUS_WORD_DATA
1da177e4	367	\| I2C_FUNC_SMBUS_WRITE_BYTE))
70313eab	368	return -ENODEV;
1da177e4	369
19f2c059 GR	370	/*
	371	* Now, we do the remaining detection. It is lousy.
	372	*
	373	* The NVB bit should be low if no EEPROM write has been requested
	374	* during the latest 10ms, which is highly improbable in our case.
	375	*/
52df6440 JD	376	conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
	377	if (conf < 0 \|\| conf & DS1621_REG_CONFIG_NVB)
	378	return -ENODEV;
	379	/* The 7 lowest bits of a temperature should always be 0. */
	380	for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) {
	381	temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]);
	382	if (temp < 0 \|\| (temp & 0x7f00))
70313eab	383	return -ENODEV;
1da177e4 LT	384	}
1da177e4 LT	385
70313eab	386	strlcpy(info->type, "ds1621", I2C_NAME_SIZE);
1da177e4	387
70313eab JD	388	return 0;
	389	}
	390
	391	static int ds1621_probe(struct i2c_client *client,
	392	const struct i2c_device_id *id)
	393	{
	394	struct ds1621_data *data;
	395	int err;
	396
e20b4b38 GR	397	data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data),
	398	GFP_KERNEL);
	399	if (!data)
	400	return -ENOMEM;
70313eab JD	401
	402	i2c_set_clientdata(client, data);
	403	mutex_init(&data->update_lock);
1da177e4	404
cd6c8a42 RC	405	data->kind = id->driver_data;
cd6c8a42 RC	406
1da177e4	407	/* Initialize the DS1621 chip */
75819f01	408	ds1621_init_client(client);
1da177e4 LT	409
1da177e4 LT	410	/* Register sysfs hooks */
19f2c059 GR	411	err = sysfs_create_group(&client->dev.kobj, &ds1621_group);
19f2c059 GR	412	if (err)
e20b4b38	413	return err;
a5ebe668	414
1beeffe4 TJ	415	data->hwmon_dev = hwmon_device_register(&client->dev);
	416	if (IS_ERR(data->hwmon_dev)) {
	417	err = PTR_ERR(data->hwmon_dev);
a5ebe668	418	goto exit_remove_files;
943b0830 MH	419	}
943b0830 MH	420
1da177e4 LT	421	return 0;
1da177e4 LT	422
19f2c059	423	exit_remove_files:
75819f01	424	sysfs_remove_group(&client->dev.kobj, &ds1621_group);
1da177e4 LT	425	return err;
	426	}
	427
70313eab	428	static int ds1621_remove(struct i2c_client *client)
1da177e4	429	{
943b0830	430	struct ds1621_data *data = i2c_get_clientdata(client);
1da177e4	431
1beeffe4	432	hwmon_device_unregister(data->hwmon_dev);
a5ebe668	433	sysfs_remove_group(&client->dev.kobj, &ds1621_group);
943b0830	434
1da177e4 LT	435	return 0;
	436	}
	437
9202add6	438	static const struct i2c_device_id ds1621_id[] = {
cd6c8a42 RC	439	{ "ds1621", ds1621 },
	440	{ "ds1625", ds1625 },
	441	{ "ds1721", ds1721 },
9202add6 JD	442	{ }
	443	};
	444	MODULE_DEVICE_TABLE(i2c, ds1621_id);
1da177e4	445
9202add6 JD	446	/* This is the driver that will be inserted */
	447	static struct i2c_driver ds1621_driver = {
	448	.class = I2C_CLASS_HWMON,
	449	.driver = {
	450	.name = "ds1621",
	451	},
	452	.probe = ds1621_probe,
	453	.remove = ds1621_remove,
	454	.id_table = ds1621_id,
	455	.detect = ds1621_detect,
c3813d6a	456	.address_list = normal_i2c,
9202add6	457	};
1da177e4	458
f0967eea	459	module_i2c_driver(ds1621_driver);
1da177e4 LT	460
	461	MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
	462	MODULE_DESCRIPTION("DS1621 driver");
	463	MODULE_LICENSE("GPL");