hwmon: Add support for Winbond W83L786NG/NR

Signed-off-by: Kevin Lo <[e-mail]>
Signed-off-by: Mark M. Hoffman <[e-mail]>

Documentation/hwmon/w83l786ng

···
+Kernel driver w83l786ng
+=====================
+
+Supported chips:
+  * Winbond W83L786NG/W83L786NR
+    Prefix: 'w83l786ng'
+    Addresses scanned: I2C 0x2e - 0x2f
+    Datasheet: http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L786NRNG09.pdf
+
+Author: Kevin Lo <[e-mail]>
+
+
+Module Parameters
+-----------------
+
+* reset boolean
+  (default 0)
+  Use 'reset=1' to reset the chip (via index 0x40, bit 7). The default
+  behavior is no chip reset to preserve BIOS settings
+
+
+Description
+-----------
+
+This driver implements support for Winbond W83L786NG/W83L786NR chips.
+
+The driver implements two temperature sensors, two fan rotation speed
+sensors, and three voltage sensors.
+
+Temperatures are measured in degrees Celsius and measurement resolution is 1
+degC for temp1 and temp2.
+
+Fan rotation speeds are reported in RPM (rotations per minute). Fan readings
+readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64
+or 128 for fan 1/2) to give the readings more range or accuracy.
+
+Voltage sensors (also known as IN sensors) report their values in millivolts.
+An alarm is triggered if the voltage has crossed a programmable minimum
+or maximum limit.
+
+/sys files
+----------
+
+pwm[1-2] - this file stores PWM duty cycle or DC value (fan speed) in range:
+	    0 (stop) to 255 (full)
+pwm[1-2]_enable - this file controls mode of fan/temperature control:
+            * 0 Manual Mode
+            * 1 Thermal Cruise
+            * 2 Smart Fan II
+            * 4 FAN_SET
+pwm[1-2]_mode - Select PWM of DC mode
+            * 0 DC
+            * 1 PWM
+tolerance[1-2] - Value in degrees of Celsius (degC) for +- T

drivers/hwmon/Kconfig

···
 	  This driver can also be built as a module.  If so, the module
 	  will be called w83l785ts.
 
+config SENSORS_W83L786NG
+	tristate "Winbond W83L786NG, W83L786NR"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for the Winbond W83L786NG
+	  and W83L786NR sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called w83l786ng.
+
 config SENSORS_W83627HF
 	tristate "Winbond W83627HF, W83627THF, W83637HF, W83687THF, W83697HF"
 	select HWMON_VID

drivers/hwmon/Makefile

···
 obj-$(CONFIG_SENSORS_VT8231)	+= vt8231.o
 obj-$(CONFIG_SENSORS_W83627EHF)	+= w83627ehf.o
 obj-$(CONFIG_SENSORS_W83L785TS)	+= w83l785ts.o
+obj-$(CONFIG_SENSORS_W83L786NG)	+= w83l786ng.o
 
 ifeq ($(CONFIG_HWMON_DEBUG_CHIP),y)
 EXTRA_CFLAGS += -DDEBUG

drivers/hwmon/w83l786ng.c

···
+/*
+    w83l786ng.c - Linux kernel driver for hardware monitoring
+    Copyright (c) 2007 Kevin Lo <[e-mail]>
+
+    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 - version 2.
+
+    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., 51 Franklin Street, Fifth Floor, Boston, MA
+    02110-1301 USA.
+*/
+
+/*
+    Supports following chips:
+
+    Chip	#vin	#fanin	#pwm	#temp	wchipid	vendid	i2c	ISA
+    w83l786ng	3	2	2	2	0x7b	0x5ca3	yes	no
+*/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-vid.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { 0x2e, 0x2f, I2C_CLIENT_END };
+
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_1(w83l786ng);
+
+static int reset;
+module_param(reset, bool, 0);
+MODULE_PARM_DESC(reset, "Set to 1 to reset chip, not recommended");
+
+#define W83L786NG_REG_IN_MIN(nr)	(0x2C + (nr) * 2)
+#define W83L786NG_REG_IN_MAX(nr)	(0x2B + (nr) * 2)
+#define W83L786NG_REG_IN(nr)		((nr) + 0x20)
+
+#define W83L786NG_REG_FAN(nr)		((nr) + 0x28)
+#define W83L786NG_REG_FAN_MIN(nr)	((nr) + 0x3B)
+
+#define W83L786NG_REG_CONFIG		0x40
+#define W83L786NG_REG_ALARM1		0x41
+#define W83L786NG_REG_ALARM2 		0x42
+#define W83L786NG_REG_GPIO_EN		0x47
+#define W83L786NG_REG_MAN_ID2		0x4C
+#define W83L786NG_REG_MAN_ID1		0x4D
+#define W83L786NG_REG_CHIP_ID		0x4E
+
+#define W83L786NG_REG_DIODE		0x53
+#define W83L786NG_REG_FAN_DIV		0x54
+#define W83L786NG_REG_FAN_CFG		0x80
+
+#define W83L786NG_REG_TOLERANCE		0x8D
+
+static const u8 W83L786NG_REG_TEMP[2][3] = {
+	{ 0x25,		/* TEMP 0 in DataSheet */
+	  0x35,		/* TEMP 0 Over in DataSheet */
+	  0x36 },	/* TEMP 0 Hyst in DataSheet */
+	{ 0x26,		/* TEMP 1 in DataSheet */
+	  0x37,		/* TEMP 1 Over in DataSheet */
+	  0x38 }	/* TEMP 1 Hyst in DataSheet */
+};
+
+static const u8 W83L786NG_PWM_MODE_SHIFT[] = {6, 7};
+static const u8 W83L786NG_PWM_ENABLE_SHIFT[] = {2, 4};
+
+/* FAN Duty Cycle, be used to control */
+static const u8 W83L786NG_REG_PWM[] = {0x81, 0x87};
+
+
+static inline u8
+FAN_TO_REG(long rpm, int div)
+{
+	if (rpm == 0)
+		return 255;
+	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
+	return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
+}
+
+#define FAN_FROM_REG(val,div)	((val) == 0   ? -1 : \
+				((val) == 255 ? 0 : \
+				1350000 / ((val) * (div))))
+
+/* for temp */
+#define TEMP_TO_REG(val)	(SENSORS_LIMIT(((val) < 0 ? (val)+0x100*1000 \
+				    : (val)) / 1000, 0, 0xff))
+#define TEMP_FROM_REG(val)	(((val) & 0x80 ? (val)-0x100 : (val)) * 1000)
+
+/* The analog voltage inputs have 8mV LSB. Since the sysfs output is
+   in mV as would be measured on the chip input pin, need to just
+   multiply/divide by 8 to translate from/to register values. */
+#define IN_TO_REG(val)          (SENSORS_LIMIT((((val) + 4) / 8), 0, 255))
+#define IN_FROM_REG(val)	((val) * 8)
+
+#define DIV_FROM_REG(val)	(1 << (val))
+
+static inline u8
+DIV_TO_REG(long val)
+{
+	int i;
+	val = SENSORS_LIMIT(val, 1, 128) >> 1;
+	for (i = 0; i < 7; i++) {
+		if (val == 0)
+			break;
+		val >>= 1;
+	}
+	return ((u8) i);
+}
+
+struct w83l786ng_data {
+	struct i2c_client client;
+	struct device *hwmon_dev;
+	struct mutex update_lock;
+	char valid;			/* !=0 if following fields are valid */
+	unsigned long last_updated;	/* In jiffies */
+	unsigned long last_nonvolatile;	/* In jiffies, last time we update the
+					   nonvolatile registers */
+
+	u8 in[3];
+	u8 in_max[3];
+	u8 in_min[3];
+	u8 fan[2];
+	u8 fan_div[2];
+	u8 fan_min[2];
+	u8 temp_type[2];
+	u8 temp[2][3];
+	u8 pwm[2];
+	u8 pwm_mode[2];	/* 0->DC variable voltage
+			   1->PWM variable duty cycle */
+
+	u8 pwm_enable[2]; /* 1->manual
+			     2->thermal cruise (also called SmartFan I) */
+	u8 tolerance[2];
+};
+
+static int w83l786ng_attach_adapter(struct i2c_adapter *adapter);
+static int w83l786ng_detect(struct i2c_adapter *adapter, int address, int kind);
+static int w83l786ng_detach_client(struct i2c_client *client);
+static void w83l786ng_init_client(struct i2c_client *client);
+static struct w83l786ng_data *w83l786ng_update_device(struct device *dev);
+
+static struct i2c_driver w83l786ng_driver = {
+	.driver = {
+		   .name = "w83l786ng",
+	},
+	.attach_adapter = w83l786ng_attach_adapter,
+	.detach_client = w83l786ng_detach_client,
+};
+
+static u8
+w83l786ng_read_value(struct i2c_client *client, u8 reg)
+{
+	return i2c_smbus_read_byte_data(client, reg);
+}
+
+static int
+w83l786ng_write_value(struct i2c_client *client, u8 reg, u8 value)
+{
+	return i2c_smbus_write_byte_data(client, reg, value);
+}
+
+/* following are the sysfs callback functions */
+#define show_in_reg(reg) \
+static ssize_t \
+show_##reg(struct device *dev, struct device_attribute *attr, \
+           char *buf) \
+{ \
+	int nr = to_sensor_dev_attr(attr)->index; \
+	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
+	return sprintf(buf,"%d\n", IN_FROM_REG(data->reg[nr])); \
+}
+
+show_in_reg(in)
+show_in_reg(in_min)
+show_in_reg(in_max)
+
+#define store_in_reg(REG, reg) \
+static ssize_t \
+store_in_##reg (struct device *dev, struct device_attribute *attr, \
+		const char *buf, size_t count) \
+{ \
+	int nr = to_sensor_dev_attr(attr)->index; \
+	struct i2c_client *client = to_i2c_client(dev); \
+	struct w83l786ng_data *data = i2c_get_clientdata(client); \
+	unsigned long val = simple_strtoul(buf, NULL, 10); \
+	mutex_lock(&data->update_lock); \
+	data->in_##reg[nr] = IN_TO_REG(val); \
+	w83l786ng_write_value(client, W83L786NG_REG_IN_##REG(nr), \
+			      data->in_##reg[nr]); \
+	mutex_unlock(&data->update_lock); \
+	return count; \
+}
+
+store_in_reg(MIN, min)
+store_in_reg(MAX, max)
+
+static struct sensor_device_attribute sda_in_input[] = {
+	SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0),
+	SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1),
+	SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2),
+};
+
+static struct sensor_device_attribute sda_in_min[] = {
+	SENSOR_ATTR(in0_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 0),
+	SENSOR_ATTR(in1_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 1),
+	SENSOR_ATTR(in2_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 2),
+};
+
+static struct sensor_device_attribute sda_in_max[] = {
+	SENSOR_ATTR(in0_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 0),
+	SENSOR_ATTR(in1_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 1),
+	SENSOR_ATTR(in2_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 2),
+};
+
+#define show_fan_reg(reg) \
+static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
+			  char *buf) \
+{ \
+	int nr = to_sensor_dev_attr(attr)->index; \
+	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
+        return sprintf(buf,"%d\n", \
+                FAN_FROM_REG(data->fan[nr], DIV_FROM_REG(data->fan_div[nr]))); \
+}
+
+show_fan_reg(fan);
+show_fan_reg(fan_min);
+
+static ssize_t
+store_fan_min(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	int nr = to_sensor_dev_attr(attr)->index;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+	u32 val;
+
+	val = simple_strtoul(buf, NULL, 10);
+	mutex_lock(&data->update_lock);
+	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
+	w83l786ng_write_value(client, W83L786NG_REG_FAN_MIN(nr),
+			      data->fan_min[nr]);
+	mutex_unlock(&data->update_lock);
+
+	return count;
+}
+
+static ssize_t
+show_fan_div(struct device *dev, struct device_attribute *attr,
+	     char *buf)
+{
+	int nr = to_sensor_dev_attr(attr)->index;
+	struct w83l786ng_data *data = w83l786ng_update_device(dev);
+	return sprintf(buf, "%u\n", DIV_FROM_REG(data->fan_div[nr]));
+}
+
+/* Note: we save and restore the fan minimum here, because its value is
+   determined in part by the fan divisor.  This follows the principle of
+   least surprise; the user doesn't expect the fan minimum to change just
+   because the divisor changed. */
+static ssize_t
+store_fan_div(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	int nr = to_sensor_dev_attr(attr)->index;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+
+	unsigned long min;
+	u8 tmp_fan_div;
+	u8 fan_div_reg;
+	u8 keep_mask = 0;
+	u8 new_shift = 0;
+
+	/* Save fan_min */
+	mutex_lock(&data->update_lock);
+	min = FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr]));
+
+	data->fan_div[nr] = DIV_TO_REG(simple_strtoul(buf, NULL, 10));
+
+	switch (nr) {
+	case 0:
+		keep_mask = 0xf8;
+		new_shift = 0;
+		break;
+	case 1:
+		keep_mask = 0x8f;
+		new_shift = 4;
+		break;
+	}
+
+	fan_div_reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV)
+					   & keep_mask;
+
+	tmp_fan_div = (data->fan_div[nr] << new_shift) & ~keep_mask;
+
+	w83l786ng_write_value(client, W83L786NG_REG_FAN_DIV,
+			      fan_div_reg | tmp_fan_div);
+
+	/* Restore fan_min */
+	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
+	w83l786ng_write_value(client, W83L786NG_REG_FAN_MIN(nr),
+			      data->fan_min[nr]);
+	mutex_unlock(&data->update_lock);
+
+	return count;
+}
+
+static struct sensor_device_attribute sda_fan_input[] = {
+	SENSOR_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0),
+	SENSOR_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1),
+};
+
+static struct sensor_device_attribute sda_fan_min[] = {
+	SENSOR_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan_min,
+		    store_fan_min, 0),
+	SENSOR_ATTR(fan2_min, S_IWUSR | S_IRUGO, show_fan_min,
+		    store_fan_min, 1),
+};
+
+static struct sensor_device_attribute sda_fan_div[] = {
+	SENSOR_ATTR(fan1_div, S_IWUSR | S_IRUGO, show_fan_div,
+		    store_fan_div, 0),
+	SENSOR_ATTR(fan2_div, S_IWUSR | S_IRUGO, show_fan_div,
+		    store_fan_div, 1),
+};
+
+
+/* read/write the temperature, includes measured value and limits */
+
+static ssize_t
+show_temp(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct sensor_device_attribute_2 *sensor_attr =
+	    to_sensor_dev_attr_2(attr);
+	int nr = sensor_attr->nr;
+	int index = sensor_attr->index;
+	struct w83l786ng_data *data = w83l786ng_update_device(dev);
+	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[nr][index]));
+}
+
+static ssize_t
+store_temp(struct device *dev, struct device_attribute *attr,
+	   const char *buf, size_t count)
+{
+	struct sensor_device_attribute_2 *sensor_attr =
+	    to_sensor_dev_attr_2(attr);
+	int nr = sensor_attr->nr;
+	int index = sensor_attr->index;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+	s32 val;
+
+	val = simple_strtol(buf, NULL, 10);
+	mutex_lock(&data->update_lock);
+	data->temp[nr][index] = TEMP_TO_REG(val);
+	w83l786ng_write_value(client, W83L786NG_REG_TEMP[nr][index],
+			      data->temp[nr][index]);
+	mutex_unlock(&data->update_lock);
+
+        return count;
+}
+
+static struct sensor_device_attribute_2 sda_temp_input[] = {
+	SENSOR_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0),
+	SENSOR_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 1, 0),
+};
+
+static struct sensor_device_attribute_2 sda_temp_max[] = {
+	SENSOR_ATTR_2(temp1_max, S_IRUGO | S_IWUSR,
+		      show_temp, store_temp, 0, 1),
+	SENSOR_ATTR_2(temp2_max, S_IRUGO | S_IWUSR,
+		      show_temp, store_temp, 1, 1),
+};
+
+static struct sensor_device_attribute_2 sda_temp_max_hyst[] = {
+	SENSOR_ATTR_2(temp1_max_hyst, S_IRUGO | S_IWUSR,
+		      show_temp, store_temp, 0, 2),
+	SENSOR_ATTR_2(temp2_max_hyst, S_IRUGO | S_IWUSR,
+		      show_temp, store_temp, 1, 2),
+};
+
+#define show_pwm_reg(reg) \
+static ssize_t show_##reg (struct device *dev, struct device_attribute *attr, \
+			   char *buf) \
+{ \
+	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
+	int nr = to_sensor_dev_attr(attr)->index; \
+	return sprintf(buf, "%d\n", data->reg[nr]); \
+}
+
+show_pwm_reg(pwm_mode)
+show_pwm_reg(pwm_enable)
+show_pwm_reg(pwm)
+
+static ssize_t
+store_pwm_mode(struct device *dev, struct device_attribute *attr,
+	       const char *buf, size_t count)
+{
+	int nr = to_sensor_dev_attr(attr)->index;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+	u32 val = simple_strtoul(buf, NULL, 10);
+	u8 reg;
+
+	if (val > 1)
+		return -EINVAL;
+	mutex_lock(&data->update_lock);
+	data->pwm_mode[nr] = val;
+	reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
+	reg &= ~(1 << W83L786NG_PWM_MODE_SHIFT[nr]);
+	if (!val)
+		reg |= 1 << W83L786NG_PWM_MODE_SHIFT[nr];
+	w83l786ng_write_value(client, W83L786NG_REG_FAN_CFG, reg);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t
+store_pwm(struct device *dev, struct device_attribute *attr,
+	  const char *buf, size_t count)
+{
+	int nr = to_sensor_dev_attr(attr)->index;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+	u32 val = SENSORS_LIMIT(simple_strtoul(buf, NULL, 10), 0, 255);
+
+	mutex_lock(&data->update_lock);
+	data->pwm[nr] = val;
+	w83l786ng_write_value(client, W83L786NG_REG_PWM[nr], val);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t
+store_pwm_enable(struct device *dev, struct device_attribute *attr,
+		 const char *buf, size_t count)
+{
+	int nr = to_sensor_dev_attr(attr)->index;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+	u32 val = simple_strtoul(buf, NULL, 10);
+
+	u8 reg;
+
+	if (!val || (val > 2))  /* only modes 1 and 2 are supported */
+		return -EINVAL;
+
+	mutex_lock(&data->update_lock);
+	reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
+	data->pwm_enable[nr] = val;
+	reg &= ~(0x02 << W83L786NG_PWM_ENABLE_SHIFT[nr]);
+	reg |= (val - 1) << W83L786NG_PWM_ENABLE_SHIFT[nr];
+	w83l786ng_write_value(client, W83L786NG_REG_FAN_CFG, reg);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static struct sensor_device_attribute sda_pwm[] = {
+	SENSOR_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 0),
+	SENSOR_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 1),
+};
+
+static struct sensor_device_attribute sda_pwm_mode[] = {
+	SENSOR_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, show_pwm_mode,
+		    store_pwm_mode, 0),
+	SENSOR_ATTR(pwm2_mode, S_IWUSR | S_IRUGO, show_pwm_mode,
+		    store_pwm_mode, 1),
+};
+
+static struct sensor_device_attribute sda_pwm_enable[] = {
+	SENSOR_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, show_pwm_enable,
+		    store_pwm_enable, 0),
+	SENSOR_ATTR(pwm2_enable, S_IWUSR | S_IRUGO, show_pwm_enable,
+		    store_pwm_enable, 1),
+};
+
+/* For Smart Fan I/Thermal Cruise and Smart Fan II */
+static ssize_t
+show_tolerance(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	int nr = to_sensor_dev_attr(attr)->index;
+	struct w83l786ng_data *data = w83l786ng_update_device(dev);
+	return sprintf(buf, "%ld\n", (long)data->tolerance[nr]);
+}
+
+static ssize_t
+store_tolerance(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	int nr = to_sensor_dev_attr(attr)->index;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+	u32 val;
+	u8 tol_tmp, tol_mask;
+
+	val = simple_strtoul(buf, NULL, 10);
+
+	mutex_lock(&data->update_lock);
+	tol_mask = w83l786ng_read_value(client,
+	    W83L786NG_REG_TOLERANCE) & ((nr == 1) ? 0x0f : 0xf0);
+	tol_tmp = SENSORS_LIMIT(val, 0, 15);
+	tol_tmp &= 0x0f;
+	data->tolerance[nr] = tol_tmp;
+	if (nr == 1) {
+		tol_tmp <<= 4;
+	}
+
+	w83l786ng_write_value(client, W83L786NG_REG_TOLERANCE,
+			      tol_mask | tol_tmp);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static struct sensor_device_attribute sda_tolerance[] = {
+	SENSOR_ATTR(pwm1_tolerance, S_IWUSR | S_IRUGO,
+		    show_tolerance, store_tolerance, 0),
+	SENSOR_ATTR(pwm2_tolerance, S_IWUSR | S_IRUGO,
+		    show_tolerance, store_tolerance, 1),
+};
+
+
+#define IN_UNIT_ATTRS(X)	\
+	&sda_in_input[X].dev_attr.attr,		\
+	&sda_in_min[X].dev_attr.attr,		\
+	&sda_in_max[X].dev_attr.attr
+
+#define FAN_UNIT_ATTRS(X)	\
+	&sda_fan_input[X].dev_attr.attr,	\
+	&sda_fan_min[X].dev_attr.attr,		\
+	&sda_fan_div[X].dev_attr.attr
+
+#define TEMP_UNIT_ATTRS(X)	\
+	&sda_temp_input[X].dev_attr.attr,	\
+	&sda_temp_max[X].dev_attr.attr,		\
+	&sda_temp_max_hyst[X].dev_attr.attr
+
+#define PWM_UNIT_ATTRS(X)	\
+	&sda_pwm[X].dev_attr.attr,		\
+	&sda_pwm_mode[X].dev_attr.attr,		\
+	&sda_pwm_enable[X].dev_attr.attr
+
+#define TOLERANCE_UNIT_ATTRS(X)	\
+	&sda_tolerance[X].dev_attr.attr
+
+static struct attribute *w83l786ng_attributes[] = {
+	IN_UNIT_ATTRS(0),
+	IN_UNIT_ATTRS(1),
+	IN_UNIT_ATTRS(2),
+	FAN_UNIT_ATTRS(0),
+	FAN_UNIT_ATTRS(1),
+	TEMP_UNIT_ATTRS(0),
+	TEMP_UNIT_ATTRS(1),
+	PWM_UNIT_ATTRS(0),
+	PWM_UNIT_ATTRS(1),
+	TOLERANCE_UNIT_ATTRS(0),
+	TOLERANCE_UNIT_ATTRS(1),
+	NULL
+};
+
+static const struct attribute_group w83l786ng_group = {
+	.attrs = w83l786ng_attributes,
+};
+
+static int
+w83l786ng_attach_adapter(struct i2c_adapter *adapter)
+{
+	if (!(adapter->class & I2C_CLASS_HWMON))
+		return 0;
+	return i2c_probe(adapter, &addr_data, w83l786ng_detect);
+}
+
+static int
+w83l786ng_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+	struct i2c_client *client;
+	struct device *dev;
+	struct w83l786ng_data *data;
+	int i, err = 0;
+	u8 reg_tmp;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_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 w83l786ng_{read,write}_value. */
+
+	if (!(data = kzalloc(sizeof(struct w83l786ng_data), GFP_KERNEL))) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	client = &data->client;
+	dev = &client->dev;
+	i2c_set_clientdata(client, data);
+	client->addr = address;
+	client->adapter = adapter;
+	client->driver = &w83l786ng_driver;
+
+	/*
+	 * Now we do the remaining detection. A negative kind means that
+	 * the driver was loaded with no force parameter (default), so we
+	 * must both detect and identify the chip (actually there is only
+	 * one possible kind of chip for now, W83L786NG). A zero kind means
+	 * that the driver was loaded with the force parameter, the detection
+	 * step shall be skipped. A positive kind means that the driver
+	 * was loaded with the force parameter and a given kind of chip is
+	 * requested, so both the detection and the identification steps
+	 * are skipped.
+	 */
+	if (kind < 0) { /* detection */
+		if (((w83l786ng_read_value(client,
+		    W83L786NG_REG_CONFIG) & 0x80) != 0x00)) {
+			dev_dbg(&adapter->dev,
+				"W83L786NG detection failed at 0x%02x.\n",
+				address);
+			goto exit_free;
+		}
+	}
+
+	if (kind <= 0) { /* identification */
+		u16 man_id;
+		u8 chip_id;
+
+		man_id = (w83l786ng_read_value(client,
+		    W83L786NG_REG_MAN_ID1) << 8) +
+		    w83l786ng_read_value(client, W83L786NG_REG_MAN_ID2);
+		chip_id = w83l786ng_read_value(client, W83L786NG_REG_CHIP_ID);
+
+		if (man_id == 0x5CA3) { /* Winbond */
+			if (chip_id == 0x80) { /* W83L786NG */
+				kind = w83l786ng;
+			}
+		}
+
+		if (kind <= 0) { /* identification failed */
+			dev_info(&adapter->dev,
+			    "Unsupported chip (man_id=0x%04X, "
+			    "chip_id=0x%02X).\n", man_id, chip_id);
+			goto exit_free;
+		}
+	}
+
+	/* Fill in the remaining client fields and put into the global list */
+	strlcpy(client->name, "w83l786ng", I2C_NAME_SIZE);
+	mutex_init(&data->update_lock);
+
+	/* Tell the I2C layer a new client has arrived */
+	if ((err = i2c_attach_client(client)))
+		goto exit_free;
+
+	/* Initialize the chip */
+	w83l786ng_init_client(client);
+
+	/* A few vars need to be filled upon startup */
+	for (i = 0; i < 2; i++) {
+		data->fan_min[i] = w83l786ng_read_value(client,
+		    W83L786NG_REG_FAN_MIN(i));
+	}
+
+	/* Update the fan divisor */
+	reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV);
+	data->fan_div[0] = reg_tmp & 0x07;
+	data->fan_div[1] = (reg_tmp >> 4) & 0x07;
+
+	/* Register sysfs hooks */
+	if ((err = sysfs_create_group(&client->dev.kobj, &w83l786ng_group)))
+		goto exit_remove;
+
+	data->hwmon_dev = hwmon_device_register(dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove;
+	}
+
+	return 0;
+
+	/* Unregister sysfs hooks */
+
+exit_remove:
+	sysfs_remove_group(&client->dev.kobj, &w83l786ng_group);
+	i2c_detach_client(client);
+exit_free:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int
+w83l786ng_detach_client(struct i2c_client *client)
+{
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+	int err;
+
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&client->dev.kobj, &w83l786ng_group);
+
+	if ((err = i2c_detach_client(client)))
+		return err;
+
+	kfree(data);
+
+	return 0;
+}
+
+static void
+w83l786ng_init_client(struct i2c_client *client)
+{
+	u8 tmp;
+
+	if (reset)
+		w83l786ng_write_value(client, W83L786NG_REG_CONFIG, 0x80);
+
+	/* Start monitoring */
+	tmp = w83l786ng_read_value(client, W83L786NG_REG_CONFIG);
+	if (!(tmp & 0x01))
+		w83l786ng_write_value(client, W83L786NG_REG_CONFIG, tmp | 0x01);
+}
+
+static struct w83l786ng_data *w83l786ng_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83l786ng_data *data = i2c_get_clientdata(client);
+	int i, j;
+	u8 reg_tmp, pwmcfg;
+
+	mutex_lock(&data->update_lock);
+	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
+	    || !data->valid) {
+		dev_dbg(&client->dev, "Updating w83l786ng data.\n");
+
+		/* Update the voltages measured value and limits */
+		for (i = 0; i < 3; i++) {
+			data->in[i] = w83l786ng_read_value(client,
+			    W83L786NG_REG_IN(i));
+			data->in_min[i] = w83l786ng_read_value(client,
+			    W83L786NG_REG_IN_MIN(i));
+			data->in_max[i] = w83l786ng_read_value(client,
+			    W83L786NG_REG_IN_MAX(i));
+		}
+
+		/* Update the fan counts and limits */
+		for (i = 0; i < 2; i++) {
+			data->fan[i] = w83l786ng_read_value(client,
+			    W83L786NG_REG_FAN(i));
+			data->fan_min[i] = w83l786ng_read_value(client,
+			    W83L786NG_REG_FAN_MIN(i));
+		}
+
+		/* Update the fan divisor */
+		reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV);
+		data->fan_div[0] = reg_tmp & 0x07;
+		data->fan_div[1] = (reg_tmp >> 4) & 0x07;
+
+		pwmcfg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
+		for (i = 0; i < 2; i++) {
+			data->pwm_mode[i] =
+			    ((pwmcfg >> W83L786NG_PWM_MODE_SHIFT[i]) & 1)
+			    ? 0 : 1;
+			data->pwm_enable[i] =
+			    ((pwmcfg >> W83L786NG_PWM_ENABLE_SHIFT[i]) & 2) + 1;
+			data->pwm[i] = w83l786ng_read_value(client,
+			    W83L786NG_REG_PWM[i]);
+		}
+
+
+		/* Update the temperature sensors */
+		for (i = 0; i < 2; i++) {
+			for (j = 0; j < 3; j++) {
+				data->temp[i][j] = w83l786ng_read_value(client,
+				    W83L786NG_REG_TEMP[i][j]);
+			}
+		}
+
+		/* Update Smart Fan I/II tolerance */
+		reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_TOLERANCE);
+		data->tolerance[0] = reg_tmp & 0x0f;
+		data->tolerance[1] = (reg_tmp >> 4) & 0x0f;
+
+		data->last_updated = jiffies;
+		data->valid = 1;
+
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return data;
+}
+
+static int __init
+sensors_w83l786ng_init(void)
+{
+	return i2c_add_driver(&w83l786ng_driver);
+}
+
+static void __exit
+sensors_w83l786ng_exit(void)
+{
+	i2c_del_driver(&w83l786ng_driver);
+}
+
+MODULE_AUTHOR("Kevin Lo");
+MODULE_DESCRIPTION("w83l786ng driver");
+MODULE_LICENSE("GPL");
+
+module_init(sensors_w83l786ng_init);
+module_exit(sensors_w83l786ng_exit);