lm90.c

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/*
 * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
 *          monitoring
 * Copyright (C) 2003-2006  Jean Delvare <[e-mail]>
 *
 * Based on the lm83 driver. The LM90 is a sensor chip made by National
 * Semiconductor. It reports up to two temperatures (its own plus up to
 * one external one) with a 0.125 deg resolution (1 deg for local
 * temperature) and a 3-4 deg accuracy. Complete datasheet can be
 * obtained from National's website at:
 *   http://www.national.com/pf/LM/LM90.html
 *
 * This driver also supports the LM89 and LM99, two other sensor chips
 * made by National Semiconductor. Both have an increased remote
 * temperature measurement accuracy (1 degree), and the LM99
 * additionally shifts remote temperatures (measured and limits) by 16
 * degrees, which allows for higher temperatures measurement. The
 * driver doesn't handle it since it can be done easily in user-space.
 * Complete datasheets can be obtained from National's website at:
 *   http://www.national.com/pf/LM/LM89.html
 *   http://www.national.com/pf/LM/LM99.html
 * Note that there is no way to differentiate between both chips.
 *
 * This driver also supports the LM86, another sensor chip made by
 * National Semiconductor. It is exactly similar to the LM90 except it
 * has a higher accuracy.
 * Complete datasheet can be obtained from National's website at:
 *   http://www.national.com/pf/LM/LM86.html
 *
 * This driver also supports the ADM1032, a sensor chip made by Analog
 * Devices. That chip is similar to the LM90, with a few differences
 * that are not handled by this driver. Complete datasheet can be
 * obtained from Analog's website at:
 *   http://www.analog.com/en/prod/0,2877,ADM1032,00.html
 * Among others, it has a higher accuracy than the LM90, much like the
 * LM86 does.
 *
 * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
 * chips made by Maxim. These chips are similar to the LM86. Complete
 * datasheet can be obtained at Maxim's website at:
 *   http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
 * Note that there is no easy way to differentiate between the three
 * variants. The extra address and features of the MAX6659 are not
 * supported by this driver. These chips lack the remote temperature
 * offset feature.
 *
 * This driver also supports the MAX6680 and MAX6681, two other sensor
 * chips made by Maxim. These are quite similar to the other Maxim
 * chips. Complete datasheet can be obtained at:
 *   http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3370
 * The MAX6680 and MAX6681 only differ in the pinout so they can be
 * treated identically.
 *
 * This driver also supports the ADT7461 chip from Analog Devices but
 * only in its "compatability mode". If an ADT7461 chip is found but
 * is configured in non-compatible mode (where its temperature
 * register values are decoded differently) it is ignored by this
 * driver. Complete datasheet can be obtained from Analog's website
 * at:
 *   http://www.analog.com/en/prod/0,2877,ADT7461,00.html
 *
 * Since the LM90 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-sysfs.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>

/*
 * Addresses to scan
 * Address is fully defined internally and cannot be changed except for
 * MAX6659, MAX6680 and MAX6681.
 * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, MAX6657 and MAX6658
 * have address 0x4c.
 * ADM1032-2, ADT7461-2, LM89-1, and LM99-1 have address 0x4d.
 * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
 * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
 * 0x4c, 0x4d or 0x4e.
 */

static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
				       0x29, 0x2a, 0x2b,
				       0x4c, 0x4d, 0x4e,
				       I2C_CLIENT_END };

/*
 * Insmod parameters
 */

I2C_CLIENT_INSMOD_7(lm90, adm1032, lm99, lm86, max6657, adt7461, max6680);

/*
 * The LM90 registers
 */

#define LM90_REG_R_MAN_ID		0xFE
#define LM90_REG_R_CHIP_ID		0xFF
#define LM90_REG_R_CONFIG1		0x03
#define LM90_REG_W_CONFIG1		0x09
#define LM90_REG_R_CONFIG2		0xBF
#define LM90_REG_W_CONFIG2		0xBF
#define LM90_REG_R_CONVRATE		0x04
#define LM90_REG_W_CONVRATE		0x0A
#define LM90_REG_R_STATUS		0x02
#define LM90_REG_R_LOCAL_TEMP		0x00
#define LM90_REG_R_LOCAL_HIGH		0x05
#define LM90_REG_W_LOCAL_HIGH		0x0B
#define LM90_REG_R_LOCAL_LOW		0x06
#define LM90_REG_W_LOCAL_LOW		0x0C
#define LM90_REG_R_LOCAL_CRIT		0x20
#define LM90_REG_W_LOCAL_CRIT		0x20
#define LM90_REG_R_REMOTE_TEMPH		0x01
#define LM90_REG_R_REMOTE_TEMPL		0x10
#define LM90_REG_R_REMOTE_OFFSH		0x11
#define LM90_REG_W_REMOTE_OFFSH		0x11
#define LM90_REG_R_REMOTE_OFFSL		0x12
#define LM90_REG_W_REMOTE_OFFSL		0x12
#define LM90_REG_R_REMOTE_HIGHH		0x07
#define LM90_REG_W_REMOTE_HIGHH		0x0D
#define LM90_REG_R_REMOTE_HIGHL		0x13
#define LM90_REG_W_REMOTE_HIGHL		0x13
#define LM90_REG_R_REMOTE_LOWH		0x08
#define LM90_REG_W_REMOTE_LOWH		0x0E
#define LM90_REG_R_REMOTE_LOWL		0x14
#define LM90_REG_W_REMOTE_LOWL		0x14
#define LM90_REG_R_REMOTE_CRIT		0x19
#define LM90_REG_W_REMOTE_CRIT		0x19
#define LM90_REG_R_TCRIT_HYST		0x21
#define LM90_REG_W_TCRIT_HYST		0x21

/*
 * Conversions and various macros
 * For local temperatures and limits, critical limits and the hysteresis
 * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
 * For remote temperatures and limits, it uses signed 11-bit values with
 * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
 */

#define TEMP1_FROM_REG(val)	((val) * 1000)
#define TEMP1_TO_REG(val)	((val) <= -128000 ? -128 : \
				 (val) >= 127000 ? 127 : \
				 (val) < 0 ? ((val) - 500) / 1000 : \
				 ((val) + 500) / 1000)
#define TEMP2_FROM_REG(val)	((val) / 32 * 125)
#define TEMP2_TO_REG(val)	((val) <= -128000 ? 0x8000 : \
				 (val) >= 127875 ? 0x7FE0 : \
				 (val) < 0 ? ((val) - 62) / 125 * 32 : \
				 ((val) + 62) / 125 * 32)
#define HYST_TO_REG(val)	((val) <= 0 ? 0 : (val) >= 30500 ? 31 : \
				 ((val) + 500) / 1000)

/* 
 * ADT7461 is almost identical to LM90 except that attempts to write
 * values that are outside the range 0 < temp < 127 are treated as
 * the boundary value. 
 */

#define TEMP1_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
				 (val) >= 127000 ? 127 : \
				 ((val) + 500) / 1000)
#define TEMP2_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
				 (val) >= 127750 ? 0x7FC0 : \
				 ((val) + 125) / 250 * 64)

/*
 * Functions declaration
 */

static int lm90_attach_adapter(struct i2c_adapter *adapter);
static int lm90_detect(struct i2c_adapter *adapter, int address,
	int kind);
static void lm90_init_client(struct i2c_client *client);
static int lm90_detach_client(struct i2c_client *client);
static struct lm90_data *lm90_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */

static struct i2c_driver lm90_driver = {
	.driver = {
		.name	= "lm90",
	},
	.id		= I2C_DRIVERID_LM90,
	.attach_adapter	= lm90_attach_adapter,
	.detach_client	= lm90_detach_client,
};

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

struct lm90_data {
	struct i2c_client client;
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */
	int kind;

	/* registers values */
	s8 temp8[5];	/* 0: local input
			   1: local low limit
			   2: local high limit
			   3: local critical limit
			   4: remote critical limit */
	s16 temp11[4];	/* 0: remote input
			   1: remote low limit
			   2: remote high limit
			   3: remote offset (except max6657) */
	u8 temp_hyst;
	u8 alarms; /* bitvector */
};

/*
 * Sysfs stuff
 */

static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
			  char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm90_data *data = lm90_update_device(dev);
	return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index]));
}

static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
			 const char *buf, size_t count)
{
	static const u8 reg[4] = {
		LM90_REG_W_LOCAL_LOW,
		LM90_REG_W_LOCAL_HIGH,
		LM90_REG_W_LOCAL_CRIT,
		LM90_REG_W_REMOTE_CRIT,
	};

	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);
	int nr = attr->index;

	mutex_lock(&data->update_lock);
	if (data->kind == adt7461)
		data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
	else
		data->temp8[nr] = TEMP1_TO_REG(val);
	i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
			   char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm90_data *data = lm90_update_device(dev);
	return sprintf(buf, "%d\n", TEMP2_FROM_REG(data->temp11[attr->index]));
}

static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
			  const char *buf, size_t count)
{
	static const u8 reg[6] = {
		LM90_REG_W_REMOTE_LOWH,
		LM90_REG_W_REMOTE_LOWL,
		LM90_REG_W_REMOTE_HIGHH,
		LM90_REG_W_REMOTE_HIGHL,
		LM90_REG_W_REMOTE_OFFSH,
		LM90_REG_W_REMOTE_OFFSL,
	};

	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);
	int nr = attr->index;

	mutex_lock(&data->update_lock);
	if (data->kind == adt7461)
		data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
	else
		data->temp11[nr] = TEMP2_TO_REG(val);
	i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
				  data->temp11[nr] >> 8);
	i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
				  data->temp11[nr] & 0xff);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
			     char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm90_data *data = lm90_update_device(dev);
	return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index])
		       - TEMP1_FROM_REG(data->temp_hyst));
}

static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
			    const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);
	long hyst;

	mutex_lock(&data->update_lock);
	hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
				  HYST_TO_REG(hyst));
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
			   char *buf)
{
	struct lm90_data *data = lm90_update_device(dev);
	return sprintf(buf, "%d\n", data->alarms);
}

static ssize_t show_alarm(struct device *dev, struct device_attribute
			  *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm90_data *data = lm90_update_device(dev);
	int bitnr = attr->index;

	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 1);
static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
	set_temp11, 1);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 2);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
	set_temp11, 2);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 3);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 4);
static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
	set_temphyst, 3);
static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
static SENSOR_DEVICE_ATTR(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
	set_temp11, 3);

/* Individual alarm files */
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
/* Raw alarm file for compatibility */
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

static struct attribute *lm90_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp2_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	&sensor_dev_attr_temp2_crit.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,

	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_fault.dev_attr.attr,
	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_max_alarm.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,