i2c: Drop I2C_CLIENT_INSMOD_2 to 8
[safe/jmp/linux-2.6] / drivers / hwmon / lm90.c
index 4b914ec..7c9bdc1 100644 (file)
@@ -1,55 +1,51 @@
 /*
  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
  *          monitoring
- * Copyright (C) 2003-2005  Jean Delvare <khali@linux-fr.org>
+ * Copyright (C) 2003-2009  Jean Delvare <khali@linux-fr.org>
  *
  * 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
+ * temperature) and a 3-4 deg accuracy.
  *
  * 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
+ * degrees, which allows for higher temperatures measurement.
  * Note that there is no way to differentiate between both chips.
+ * When device is auto-detected, the driver will assume an LM99.
  *
  * 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://products.analog.com/products/info.asp?product=ADM1032
- * Among others, it has a higher accuracy than the LM90, much like the
- * LM86 does.
+ * that are not handled by this driver. 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
+ * chips made by Maxim. These chips are similar to the LM86.
  * 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.
+ * supported by this driver. These chips lack the remote temperature
+ * offset feature.
  *
- * 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://products.analog.com/products/info.asp?product=ADT7461
+ * This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
+ * MAX6692 chips made by Maxim.  These are again similar to the LM86,
+ * but they use unsigned temperature values and can report temperatures
+ * from 0 to 145 degrees.
+ *
+ * This driver also supports the MAX6680 and MAX6681, two other sensor
+ * chips made by Maxim. These are quite similar to the other Maxim
+ * chips. 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.
+ * It's supported in both compatibility and extended mode. It is mostly
+ * compatible with LM90 except for a data format difference for the
+ * temperature value registers.
  *
  * Since the LM90 was the first chipset supported by this driver, most
  * comments will refer to this chipset, but are actually general and
 #include <linux/slab.h>
 #include <linux/jiffies.h>
 #include <linux/i2c.h>
-#include <linux/i2c-sensor.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.
- * LM86, LM89, LM90, LM99, ADM1032, MAX6657 and MAX6658 have address 0x4c.
- * LM89-1, and LM99-1 have address 0x4d.
+ * MAX6659, MAX6680 and MAX6681.
+ * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, MAX6649, MAX6657
+ * and MAX6658 have address 0x4c.
+ * ADM1032-2, ADT7461-2, LM89-1, LM99-1 and MAX6646 have address 0x4d.
+ * MAX6647 has address 0x4e.
  * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
- * ADT7461 always has address 0x4c.
+ * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
+ * 0x4c, 0x4d or 0x4e.
  */
 
-static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
-
-/*
- * Insmod parameters
- */
+static const unsigned short normal_i2c[] = {
+       0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
 
-SENSORS_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
+enum chips { lm90, adm1032, lm99, lm86, max6657, adt7461, max6680, max6646 };
 
 /*
  * The LM90 registers
@@ -137,62 +134,59 @@ SENSORS_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
 #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.
- */
+/* MAX6646/6647/6649/6657/6658/6659 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 MAX6657_REG_R_LOCAL_TEMPL      0x11
 
-#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)
+/*
+ * Device flags
+ */
+#define LM90_FLAG_ADT7461_EXT          0x01    /* ADT7461 extended mode */
 
 /*
  * Functions declaration
  */
 
-static int lm90_attach_adapter(struct i2c_adapter *adapter);
-static int lm90_detect(struct i2c_adapter *adapter, int address,
-       int kind);
+static int lm90_detect(struct i2c_client *client, struct i2c_board_info *info);
+static int lm90_probe(struct i2c_client *client,
+                     const struct i2c_device_id *id);
 static void lm90_init_client(struct i2c_client *client);
-static int lm90_detach_client(struct i2c_client *client);
+static int lm90_remove(struct i2c_client *client);
 static struct lm90_data *lm90_update_device(struct device *dev);
 
 /*
  * Driver data (common to all clients)
  */
 
+static const struct i2c_device_id lm90_id[] = {
+       { "adm1032", adm1032 },
+       { "adt7461", adt7461 },
+       { "lm90", lm90 },
+       { "lm86", lm86 },
+       { "lm89", lm86 },
+       { "lm99", lm99 },
+       { "max6646", max6646 },
+       { "max6647", max6646 },
+       { "max6649", max6646 },
+       { "max6657", max6657 },
+       { "max6658", max6657 },
+       { "max6659", max6657 },
+       { "max6680", max6680 },
+       { "max6681", max6680 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, lm90_id);
+
 static struct i2c_driver lm90_driver = {
-       .owner          = THIS_MODULE,
-       .name           = "lm90",
-       .id             = I2C_DRIVERID_LM90,
-       .flags          = I2C_DF_NOTIFY,
-       .attach_adapter = lm90_attach_adapter,
-       .detach_client  = lm90_detach_client,
+       .class          = I2C_CLASS_HWMON,
+       .driver = {
+               .name   = "lm90",
+       },
+       .probe          = lm90_probe,
+       .remove         = lm90_remove,
+       .id_table       = lm90_id,
+       .detect         = lm90_detect,
+       .address_list   = normal_i2c,
 };
 
 /*
@@ -200,27 +194,155 @@ static struct i2c_driver lm90_driver = {
  */
 
 struct lm90_data {
-       struct i2c_client client;
-       struct class_device *class_dev;
-       struct semaphore update_lock;
+       struct device *hwmon_dev;
+       struct mutex update_lock;
        char valid; /* zero until following fields are valid */
        unsigned long last_updated; /* in jiffies */
        int kind;
+       int flags;
 
        /* 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[3];  /* 0: remote input
+       s8 temp8[4];    /* 0: local low limit
+                          1: local high limit
+                          2: local critical limit
+                          3: remote critical limit */
+       s16 temp11[5];  /* 0: remote input
                           1: remote low limit
-                          2: remote high limit */
+                          2: remote high limit
+                          3: remote offset (except max6646 and max6657)
+                          4: local input */
        u8 temp_hyst;
        u8 alarms; /* bitvector */
 };
 
 /*
+ * Conversions
+ * 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.  Some
+ * Maxim chips use unsigned values.
+ */
+
+static inline int temp_from_s8(s8 val)
+{
+       return val * 1000;
+}
+
+static inline int temp_from_u8(u8 val)
+{
+       return val * 1000;
+}
+
+static inline int temp_from_s16(s16 val)
+{
+       return val / 32 * 125;
+}
+
+static inline int temp_from_u16(u16 val)
+{
+       return val / 32 * 125;
+}
+
+static s8 temp_to_s8(long val)
+{
+       if (val <= -128000)
+               return -128;
+       if (val >= 127000)
+               return 127;
+       if (val < 0)
+               return (val - 500) / 1000;
+       return (val + 500) / 1000;
+}
+
+static u8 temp_to_u8(long val)
+{
+       if (val <= 0)
+               return 0;
+       if (val >= 255000)
+               return 255;
+       return (val + 500) / 1000;
+}
+
+static s16 temp_to_s16(long val)
+{
+       if (val <= -128000)
+               return 0x8000;
+       if (val >= 127875)
+               return 0x7FE0;
+       if (val < 0)
+               return (val - 62) / 125 * 32;
+       return (val + 62) / 125 * 32;
+}
+
+static u8 hyst_to_reg(long val)
+{
+       if (val <= 0)
+               return 0;
+       if (val >= 30500)
+               return 31;
+       return (val + 500) / 1000;
+}
+
+/*
+ * ADT7461 in compatibility mode 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.
+ *
+ * ADT7461 in "extended mode" operation uses unsigned integers offset by
+ * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
+ */
+static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
+{
+       if (data->flags & LM90_FLAG_ADT7461_EXT)
+               return (val - 64) * 1000;
+       else
+               return temp_from_s8(val);
+}
+
+static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
+{
+       if (data->flags & LM90_FLAG_ADT7461_EXT)
+               return (val - 0x4000) / 64 * 250;
+       else
+               return temp_from_s16(val);
+}
+
+static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
+{
+       if (data->flags & LM90_FLAG_ADT7461_EXT) {
+               if (val <= -64000)
+                       return 0;
+               if (val >= 191000)
+                       return 0xFF;
+               return (val + 500 + 64000) / 1000;
+       } else {
+               if (val <= 0)
+                       return 0;
+               if (val >= 127000)
+                       return 127;
+               return (val + 500) / 1000;
+       }
+}
+
+static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
+{
+       if (data->flags & LM90_FLAG_ADT7461_EXT) {
+               if (val <= -64000)
+                       return 0;
+               if (val >= 191750)
+                       return 0xFFC0;
+               return (val + 64000 + 125) / 250 * 64;
+       } else {
+               if (val <= 0)
+                       return 0;
+               if (val >= 127750)
+                       return 0x7FC0;
+               return (val + 125) / 250 * 64;
+       }
+}
+
+/*
  * Sysfs stuff
  */
 
@@ -229,7 +351,20 @@ static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
 {
        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]));
+       int temp;
+
+       if (data->kind == adt7461)
+               temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
+       else if (data->kind == max6646)
+               temp = temp_from_u8(data->temp8[attr->index]);
+       else
+               temp = temp_from_s8(data->temp8[attr->index]);
+
+       /* +16 degrees offset for temp2 for the LM99 */
+       if (data->kind == lm99 && attr->index == 3)
+               temp += 16000;
+
+       return sprintf(buf, "%d\n", temp);
 }
 
 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
@@ -248,13 +383,19 @@ static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
        long val = simple_strtol(buf, NULL, 10);
        int nr = attr->index;
 
-       down(&data->update_lock);
+       /* +16 degrees offset for temp2 for the LM99 */
+       if (data->kind == lm99 && attr->index == 3)
+               val -= 16000;
+
+       mutex_lock(&data->update_lock);
        if (data->kind == adt7461)
-               data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
+               data->temp8[nr] = temp_to_u8_adt7461(data, val);
+       else if (data->kind == max6646)
+               data->temp8[nr] = temp_to_u8(val);
        else
-               data->temp8[nr] = TEMP1_TO_REG(val);
-       i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
-       up(&data->update_lock);
+               data->temp8[nr] = temp_to_s8(val);
+       i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
+       mutex_unlock(&data->update_lock);
        return count;
 }
 
@@ -263,17 +404,32 @@ static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
 {
        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]));
+       int temp;
+
+       if (data->kind == adt7461)
+               temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
+       else if (data->kind == max6646)
+               temp = temp_from_u16(data->temp11[attr->index]);
+       else
+               temp = temp_from_s16(data->temp11[attr->index]);
+
+       /* +16 degrees offset for temp2 for the LM99 */
+       if (data->kind == lm99 &&  attr->index <= 2)
+               temp += 16000;
+
+       return sprintf(buf, "%d\n", temp);
 }
 
 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
                          const char *buf, size_t count)
 {
-       static const u8 reg[4] = {
+       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);
@@ -282,16 +438,27 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
        long val = simple_strtol(buf, NULL, 10);
        int nr = attr->index;
 
-       down(&data->update_lock);
+       /* +16 degrees offset for temp2 for the LM99 */
+       if (data->kind == lm99 && attr->index <= 2)
+               val -= 16000;
+
+       mutex_lock(&data->update_lock);
        if (data->kind == adt7461)
-               data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
+               data->temp11[nr] = temp_to_u16_adt7461(data, val);
+       else if (data->kind == max6657 || data->kind == max6680)
+               data->temp11[nr] = temp_to_s8(val) << 8;
+       else if (data->kind == max6646)
+               data->temp11[nr] = temp_to_u8(val) << 8;
        else
-               data->temp11[nr] = TEMP2_TO_REG(val);
+               data->temp11[nr] = temp_to_s16(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);
-       up(&data->update_lock);
+       if (data->kind != max6657 && data->kind != max6680
+           && data->kind != max6646)
+               i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
+                                         data->temp11[nr] & 0xff);
+       mutex_unlock(&data->update_lock);
        return count;
 }
 
@@ -300,8 +467,20 @@ static ssize_t show_temphyst(struct device *dev, struct device_attribute *devatt
 {
        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));
+       int temp;
+
+       if (data->kind == adt7461)
+               temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
+       else if (data->kind == max6646)
+               temp = temp_from_u8(data->temp8[attr->index]);
+       else
+               temp = temp_from_s8(data->temp8[attr->index]);
+
+       /* +16 degrees offset for temp2 for the LM99 */
+       if (data->kind == lm99 && attr->index == 3)
+               temp += 16000;
+
+       return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
 }
 
 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
@@ -310,13 +489,20 @@ static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
        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;
+       int temp;
+
+       mutex_lock(&data->update_lock);
+       if (data->kind == adt7461)
+               temp = temp_from_u8_adt7461(data, data->temp8[2]);
+       else if (data->kind == max6646)
+               temp = temp_from_u8(data->temp8[2]);
+       else
+               temp = temp_from_s8(data->temp8[2]);
 
-       down(&data->update_lock);
-       hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
+       data->temp_hyst = hyst_to_reg(temp - val);
        i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
-                                 HYST_TO_REG(hyst));
-       up(&data->update_lock);
+                                 data->temp_hyst);
+       mutex_unlock(&data->update_lock);
        return count;
 }
 
@@ -327,213 +513,315 @@ static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
        return sprintf(buf, "%d\n", data->alarms);
 }
 
-static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
+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_temp11, NULL, 4);
 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);
+       set_temp8, 0);
 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);
+       set_temp8, 1);
 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);
+       set_temp8, 2);
 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
-       set_temp8, 4);
+       set_temp8, 3);
 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);
+       set_temphyst, 2);
+static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 3);
+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,
+       NULL
+};
+
+static const struct attribute_group lm90_group = {
+       .attrs = lm90_attributes,
+};
+
+/* pec used for ADM1032 only */
+static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
+                       char *buf)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
+}
+
+static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
+                      const char *buf, size_t count)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       long val = simple_strtol(buf, NULL, 10);
+
+       switch (val) {
+       case 0:
+               client->flags &= ~I2C_CLIENT_PEC;
+               break;
+       case 1:
+               client->flags |= I2C_CLIENT_PEC;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return count;
+}
+
+static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
+
 /*
  * Real code
  */
 
-static int lm90_attach_adapter(struct i2c_adapter *adapter)
+/* The ADM1032 supports PEC but not on write byte transactions, so we need
+   to explicitly ask for a transaction without PEC. */
+static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
 {
-       if (!(adapter->class & I2C_CLASS_HWMON))
-               return 0;
-       return i2c_detect(adapter, &addr_data, lm90_detect);
+       return i2c_smbus_xfer(client->adapter, client->addr,
+                             client->flags & ~I2C_CLIENT_PEC,
+                             I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
 }
 
-/*
- * The following function does more than just detection. If detection
- * succeeds, it also registers the new chip.
- */
-static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
+/* It is assumed that client->update_lock is held (unless we are in
+   detection or initialization steps). This matters when PEC is enabled,
+   because we don't want the address pointer to change between the write
  byte and the read byte transactions. */
+static int lm90_read_reg(struct i2c_client* client, u8 reg, u8 *value)
 {
-       struct i2c_client *new_client;
-       struct lm90_data *data;
-       int err = 0;
-       const char *name = "";
+       int err;
 
-       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
-               goto exit;
+       if (client->flags & I2C_CLIENT_PEC) {
+               err = adm1032_write_byte(client, reg);
+               if (err >= 0)
+                       err = i2c_smbus_read_byte(client);
+       } else
+               err = i2c_smbus_read_byte_data(client, reg);
 
-       if (!(data = kmalloc(sizeof(struct lm90_data), GFP_KERNEL))) {
-               err = -ENOMEM;
-               goto exit;
+       if (err < 0) {
+               dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
+                        reg, err);
+               return err;
        }
-       memset(data, 0, sizeof(struct lm90_data));
+       *value = err;
 
-       /* The common I2C client data is placed right before the
-          LM90-specific data. */
-       new_client = &data->client;
-       i2c_set_clientdata(new_client, data);
-       new_client->addr = address;
-       new_client->adapter = adapter;
-       new_client->driver = &lm90_driver;
-       new_client->flags = 0;
+       return 0;
+}
 
-       /*
-        * 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. 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.
-        */
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm90_detect(struct i2c_client *new_client,
+                      struct i2c_board_info *info)
+{
+       struct i2c_adapter *adapter = new_client->adapter;
+       int address = new_client->addr;
+       const char *name = NULL;
+       int man_id, chip_id, reg_config1, reg_convrate;
 
-       /* Default to an LM90 if forced */
-       if (kind == 0)
-               kind = lm90;
-
-       if (kind < 0) { /* detection and identification */
-               u8 man_id, chip_id, reg_config1, reg_convrate;
-
-               man_id = i2c_smbus_read_byte_data(new_client,
-                        LM90_REG_R_MAN_ID);
-               chip_id = i2c_smbus_read_byte_data(new_client,
-                         LM90_REG_R_CHIP_ID);
-               reg_config1 = i2c_smbus_read_byte_data(new_client,
-                             LM90_REG_R_CONFIG1);
-               reg_convrate = i2c_smbus_read_byte_data(new_client,
-                              LM90_REG_R_CONVRATE);
-               
-               if (man_id == 0x01) { /* National Semiconductor */
-                       u8 reg_config2;
-
-                       reg_config2 = i2c_smbus_read_byte_data(new_client,
-                                     LM90_REG_R_CONFIG2);
-
-                       if ((reg_config1 & 0x2A) == 0x00
-                        && (reg_config2 & 0xF8) == 0x00
-                        && reg_convrate <= 0x09) {
-                               if (address == 0x4C
-                                && (chip_id & 0xF0) == 0x20) { /* LM90 */
-                                       kind = lm90;
-                               } else
-                               if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
-                                       kind = lm99;
-                               } else
-                               if (address == 0x4C
-                                && (chip_id & 0xF0) == 0x10) { /* LM86 */
-                                       kind = lm86;
-                               }
-                       }
-               } else
-               if (man_id == 0x41) { /* Analog Devices */
+       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+               return -ENODEV;
+
+       /* detection and identification */
+       if ((man_id = i2c_smbus_read_byte_data(new_client,
+                                               LM90_REG_R_MAN_ID)) < 0
+        || (chip_id = i2c_smbus_read_byte_data(new_client,
+                                               LM90_REG_R_CHIP_ID)) < 0
+        || (reg_config1 = i2c_smbus_read_byte_data(new_client,
+                                               LM90_REG_R_CONFIG1)) < 0
+        || (reg_convrate = i2c_smbus_read_byte_data(new_client,
+                                               LM90_REG_R_CONVRATE)) < 0)
+               return -ENODEV;
+
+       if ((address == 0x4C || address == 0x4D)
+        && man_id == 0x01) { /* National Semiconductor */
+               int reg_config2;
+
+               reg_config2 = i2c_smbus_read_byte_data(new_client,
+                                               LM90_REG_R_CONFIG2);
+               if (reg_config2 < 0)
+                       return -ENODEV;
+
+               if ((reg_config1 & 0x2A) == 0x00
+                && (reg_config2 & 0xF8) == 0x00
+                && reg_convrate <= 0x09) {
                        if (address == 0x4C
-                        && (chip_id & 0xF0) == 0x40 /* ADM1032 */
-                        && (reg_config1 & 0x3F) == 0x00
-                        && reg_convrate <= 0x0A) {
-                               kind = adm1032;
+                        && (chip_id & 0xF0) == 0x20) { /* LM90 */
+                               name = "lm90";
+                       } else
+                       if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
+                               name = "lm99";
+                               dev_info(&adapter->dev,
+                                        "Assuming LM99 chip at 0x%02x\n",
+                                        address);
+                               dev_info(&adapter->dev,
+                                        "If it is an LM89, instantiate it "
+                                        "with the new_device sysfs "
+                                        "interface\n");
                        } else
-                       if (address == 0x4c
-                        && chip_id == 0x51 /* ADT7461 */
-                        && (reg_config1 & 0x1F) == 0x00 /* check compat mode */
-                        && reg_convrate <= 0x0A) {
-                               kind = adt7461;
+                       if (address == 0x4C
+                        && (chip_id & 0xF0) == 0x10) { /* LM86 */
+                               name = "lm86";
                        }
+               }
+       } else
+       if ((address == 0x4C || address == 0x4D)
+        && man_id == 0x41) { /* Analog Devices */
+               if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
+                && (reg_config1 & 0x3F) == 0x00
+                && reg_convrate <= 0x0A) {
+                       name = "adm1032";
+                       /* The ADM1032 supports PEC, but only if combined
+                          transactions are not used. */
+                       if (i2c_check_functionality(adapter,
+                                                   I2C_FUNC_SMBUS_BYTE))
+                               info->flags |= I2C_CLIENT_PEC;
                } else
-               if (man_id == 0x4D) { /* Maxim */
-                       /*
-                        * The Maxim variants do NOT have a chip_id register.
-                        * Reading from that address will return the last read
-                        * value, which in our case is those of the man_id
-                        * register. Likewise, the config1 register seems to
-                        * lack a low nibble, so the value will be those of the
-                        * previous read, so in our case those of the man_id
-                        * register.
-                        */
-                       if (chip_id == man_id
-                        && (reg_config1 & 0x1F) == (man_id & 0x0F)
-                        && reg_convrate <= 0x09) {
-                               kind = max6657;
-                       }
+               if (chip_id == 0x51 /* ADT7461 */
+                && (reg_config1 & 0x1B) == 0x00
+                && reg_convrate <= 0x0A) {
+                       name = "adt7461";
                }
-
-               if (kind <= 0) { /* identification failed */
-                       dev_info(&adapter->dev,
-                           "Unsupported chip (man_id=0x%02X, "
-                           "chip_id=0x%02X).\n", man_id, chip_id);
-                       goto exit_free;
+       } else
+       if (man_id == 0x4D) { /* Maxim */
+               /*
+                * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
+                * register. Reading from that address will return the last
+                * read value, which in our case is those of the man_id
+                * register. Likewise, the config1 register seems to lack a
+                * low nibble, so the value will be those of the previous
+                * read, so in our case those of the man_id register.
+                */
+               if (chip_id == man_id
+                && (address == 0x4C || address == 0x4D)
+                && (reg_config1 & 0x1F) == (man_id & 0x0F)
+                && reg_convrate <= 0x09) {
+                       name = "max6657";
+               } else
+               /*
+                * The chip_id register of the MAX6680 and MAX6681 holds the
+                * revision of the chip. The lowest bit of the config1 register
+                * is unused and should return zero when read, so should the
+                * second to last bit of config1 (software reset).
+                */
+               if (chip_id == 0x01
+                && (reg_config1 & 0x03) == 0x00
+                && reg_convrate <= 0x07) {
+                       name = "max6680";
+               } else
+               /*
+                * The chip_id register of the MAX6646/6647/6649 holds the
+                * revision of the chip. The lowest 6 bits of the config1
+                * register are unused and should return zero when read.
+                */
+               if (chip_id == 0x59
+                && (reg_config1 & 0x3f) == 0x00
+                && reg_convrate <= 0x07) {
+                       name = "max6646";
                }
        }
 
-       if (kind == lm90) {
-               name = "lm90";
-       } else if (kind == adm1032) {
-               name = "adm1032";
-       } else if (kind == lm99) {
-               name = "lm99";
-       } else if (kind == lm86) {
-               name = "lm86";
-       } else if (kind == max6657) {
-               name = "max6657";
-       } else if (kind == adt7461) {
-               name = "adt7461";
+       if (!name) { /* identification failed */
+               dev_dbg(&adapter->dev,
+                       "Unsupported chip at 0x%02x (man_id=0x%02X, "
+                       "chip_id=0x%02X)\n", address, man_id, chip_id);
+               return -ENODEV;
        }
 
-       /* We can fill in the remaining client fields */
-       strlcpy(new_client->name, name, I2C_NAME_SIZE);
-       data->valid = 0;
-       data->kind = kind;
-       init_MUTEX(&data->update_lock);
+       strlcpy(info->type, name, I2C_NAME_SIZE);
 
-       /* Tell the I2C layer a new client has arrived */
-       if ((err = i2c_attach_client(new_client)))
-               goto exit_free;
+       return 0;
+}
+
+static int lm90_probe(struct i2c_client *new_client,
+                     const struct i2c_device_id *id)
+{
+       struct i2c_adapter *adapter = to_i2c_adapter(new_client->dev.parent);
+       struct lm90_data *data;
+       int err;
+
+       data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL);
+       if (!data) {
+               err = -ENOMEM;
+               goto exit;
+       }
+       i2c_set_clientdata(new_client, data);
+       mutex_init(&data->update_lock);
+
+       /* Set the device type */
+       data->kind = id->driver_data;
+       if (data->kind == adm1032) {
+               if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
+                       new_client->flags &= ~I2C_CLIENT_PEC;
+       }
 
        /* Initialize the LM90 chip */
        lm90_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;
+       if ((err = sysfs_create_group(&new_client->dev.kobj, &lm90_group)))
+               goto exit_free;
+       if (new_client->flags & I2C_CLIENT_PEC) {
+               if ((err = device_create_file(&new_client->dev,
+                                             &dev_attr_pec)))
+                       goto exit_remove_files;
+       }
+       if (data->kind != max6657 && data->kind != max6646) {
+               if ((err = device_create_file(&new_client->dev,
+                               &sensor_dev_attr_temp2_offset.dev_attr)))
+                       goto exit_remove_files;
        }
 
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp1_input.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp2_input.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp1_min.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp2_min.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp1_max.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp2_max.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp1_crit.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp2_crit.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp1_crit_hyst.dev_attr);
-       device_create_file(&new_client->dev,
-                          &sensor_dev_attr_temp2_crit_hyst.dev_attr);
-       device_create_file(&new_client->dev, &dev_attr_alarms);
+       data->hwmon_dev = hwmon_device_register(&new_client->dev);
+       if (IS_ERR(data->hwmon_dev)) {
+               err = PTR_ERR(data->hwmon_dev);
+               goto exit_remove_files;
+       }
 
        return 0;
 
-exit_detach:
-       i2c_detach_client(new_client);
+exit_remove_files:
+       sysfs_remove_group(&new_client->dev.kobj, &lm90_group);
+       device_remove_file(&new_client->dev, &dev_attr_pec);
 exit_free:
        kfree(data);
 exit:
@@ -542,33 +830,84 @@ exit:
 
 static void lm90_init_client(struct i2c_client *client)
 {
-       u8 config;
+       u8 config, config_orig;
+       struct lm90_data *data = i2c_get_clientdata(client);
 
        /*
         * Start the conversions.
         */
        i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
                                  5); /* 2 Hz */
-       config = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
-       if (config & 0x40)
-               i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
-                                         config & 0xBF); /* run */
+       if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
+               dev_warn(&client->dev, "Initialization failed!\n");
+               return;
+       }
+       config_orig = config;
+
+       /* Check Temperature Range Select */
+       if (data->kind == adt7461) {
+               if (config & 0x04)
+                       data->flags |= LM90_FLAG_ADT7461_EXT;
+       }
+
+       /*
+        * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
+        * 0.125 degree resolution) and range (0x08, extend range
+        * to -64 degree) mode for the remote temperature sensor.
+        */
+       if (data->kind == max6680) {
+               config |= 0x18;
+       }
+
+       config &= 0xBF; /* run */
+       if (config != config_orig) /* Only write if changed */
+               i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
 }
 
-static int lm90_detach_client(struct i2c_client *client)
+static int lm90_remove(struct i2c_client *client)
 {
        struct lm90_data *data = i2c_get_clientdata(client);
-       int err;
 
-       hwmon_device_unregister(data->class_dev);
+       hwmon_device_unregister(data->hwmon_dev);
+       sysfs_remove_group(&client->dev.kobj, &lm90_group);
+       device_remove_file(&client->dev, &dev_attr_pec);
+       if (data->kind != max6657 && data->kind != max6646)
+               device_remove_file(&client->dev,
+                                  &sensor_dev_attr_temp2_offset.dev_attr);
+
+       kfree(data);
+       return 0;
+}
+
+static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
+{
+       int err;
+       u8 oldh, newh, l;
 
-       if ((err = i2c_detach_client(client))) {
-               dev_err(&client->dev, "Client deregistration failed, "
-                       "client not detached.\n");
+       /*
+        * There is a trick here. We have to read two registers to have the
+        * sensor temperature, but we have to beware a conversion could occur
+        * inbetween the readings. The datasheet says we should either use
+        * the one-shot conversion register, which we don't want to do
+        * (disables hardware monitoring) or monitor the busy bit, which is
+        * impossible (we can't read the values and monitor that bit at the
+        * exact same time). So the solution used here is to read the high
+        * byte once, then the low byte, then the high byte again. If the new
+        * high byte matches the old one, then we have a valid reading. Else
+        * we have to read the low byte again, and now we believe we have a
+        * correct reading.
+        */
+       if ((err = lm90_read_reg(client, regh, &oldh))
+        || (err = lm90_read_reg(client, regl, &l))
+        || (err = lm90_read_reg(client, regh, &newh)))
                return err;
+       if (oldh != newh) {
+               err = lm90_read_reg(client, regl, &l);
+               if (err)
+                       return err;
        }
+       *value = (newh << 8) | l;
 
-       kfree(data);
        return 0;
 }
 
@@ -577,75 +916,61 @@ static struct lm90_data *lm90_update_device(struct device *dev)
        struct i2c_client *client = to_i2c_client(dev);
        struct lm90_data *data = i2c_get_clientdata(client);
 
-       down(&data->update_lock);
+       mutex_lock(&data->update_lock);
 
        if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
-               u8 oldh, newh;
+               u8 h, l;
 
                dev_dbg(&client->dev, "Updating lm90 data.\n");
-               data->temp8[0] = i2c_smbus_read_byte_data(client,
-                                LM90_REG_R_LOCAL_TEMP);
-               data->temp8[1] = i2c_smbus_read_byte_data(client,
-                                LM90_REG_R_LOCAL_LOW);
-               data->temp8[2] = i2c_smbus_read_byte_data(client,
-                                LM90_REG_R_LOCAL_HIGH);
-               data->temp8[3] = i2c_smbus_read_byte_data(client,
-                                LM90_REG_R_LOCAL_CRIT);
-               data->temp8[4] = i2c_smbus_read_byte_data(client,
-                                LM90_REG_R_REMOTE_CRIT);
-               data->temp_hyst = i2c_smbus_read_byte_data(client,
-                                 LM90_REG_R_TCRIT_HYST);
+               lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[0]);
+               lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[1]);
+               lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[2]);
+               lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
+               lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
+
+               if (data->kind == max6657 || data->kind == max6646) {
+                       lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
+                                   MAX6657_REG_R_LOCAL_TEMPL,
+                                   &data->temp11[4]);
+               } else {
+                       if (lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP,
+                                         &h) == 0)
+                               data->temp11[4] = h << 8;
+               }
+               lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
+                           LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);
+
+               if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
+                       data->temp11[1] = h << 8;
+                       if (data->kind != max6657 && data->kind != max6680
+                        && data->kind != max6646
+                        && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
+                                         &l) == 0)
+                               data->temp11[1] |= l;
+               }
+               if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
+                       data->temp11[2] = h << 8;
+                       if (data->kind != max6657 && data->kind != max6680
+                        && data->kind != max6646
+                        && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
+                                         &l) == 0)
+                               data->temp11[2] |= l;
+               }
 
-               /*
-                * There is a trick here. We have to read two registers to
-                * have the remote sensor temperature, but we have to beware
-                * a conversion could occur inbetween the readings. The
-                * datasheet says we should either use the one-shot
-                * conversion register, which we don't want to do (disables
-                * hardware monitoring) or monitor the busy bit, which is
-                * impossible (we can't read the values and monitor that bit
-                * at the exact same time). So the solution used here is to
-                * read the high byte once, then the low byte, then the high
-                * byte again. If the new high byte matches the old one,
-                * then we have a valid reading. Else we have to read the low
-                * byte again, and now we believe we have a correct reading.
-                */
-               oldh = i2c_smbus_read_byte_data(client,
-                      LM90_REG_R_REMOTE_TEMPH);
-               data->temp11[0] = i2c_smbus_read_byte_data(client,
-                                 LM90_REG_R_REMOTE_TEMPL);
-               newh = i2c_smbus_read_byte_data(client,
-                      LM90_REG_R_REMOTE_TEMPH);
-               if (newh != oldh) {
-                       data->temp11[0] = i2c_smbus_read_byte_data(client,
-                                         LM90_REG_R_REMOTE_TEMPL);
-#ifdef DEBUG
-                       oldh = i2c_smbus_read_byte_data(client,
-                              LM90_REG_R_REMOTE_TEMPH);
-                       /* oldh is actually newer */
-                       if (newh != oldh)
-                               dev_warn(&client->dev, "Remote temperature may be "
-                                        "wrong.\n");
-#endif
+               if (data->kind != max6657 && data->kind != max6646) {
+                       if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
+                                         &h) == 0
+                        && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
+                                         &l) == 0)
+                               data->temp11[3] = (h << 8) | l;
                }
-               data->temp11[0] |= (newh << 8);
-
-               data->temp11[1] = (i2c_smbus_read_byte_data(client,
-                                  LM90_REG_R_REMOTE_LOWH) << 8) +
-                                  i2c_smbus_read_byte_data(client,
-                                  LM90_REG_R_REMOTE_LOWL);
-               data->temp11[2] = (i2c_smbus_read_byte_data(client,
-                                  LM90_REG_R_REMOTE_HIGHH) << 8) +
-                                  i2c_smbus_read_byte_data(client,
-                                  LM90_REG_R_REMOTE_HIGHL);
-               data->alarms = i2c_smbus_read_byte_data(client,
-                              LM90_REG_R_STATUS);
+               lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);
 
                data->last_updated = jiffies;
                data->valid = 1;
        }
 
-       up(&data->update_lock);
+       mutex_unlock(&data->update_lock);
 
        return data;
 }