hwmon: (lm90) Add support for ADT7461A and NCT1008

This patch adds support for ADT7461A and NCT1008 to the lm90 driver.
Both chips have identical functionality and report the same manufacturing ID
and device ID values.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Documentation/hwmon/lm90

@@ -32,6 +32,16 @@ Supported chips:
     Addresses scanned: I2C 0x4c and 0x4d
     Datasheet: Publicly available at the ON Semiconductor website
                http://www.onsemi.com/PowerSolutions/product.do?id=ADT7461
+  * Analog Devices ADT7461A
+    Prefix: 'adt7461a'
+    Addresses scanned: I2C 0x4c and 0x4d
+    Datasheet: Publicly available at the ON Semiconductor website
+               http://www.onsemi.com/PowerSolutions/product.do?id=ADT7461A
+  * ON Semiconductor NCT1008
+    Prefix: 'nct1008'
+    Addresses scanned: I2C 0x4c and 0x4d
+    Datasheet: Publicly available at the ON Semiconductor website
+               http://www.onsemi.com/PowerSolutions/product.do?id=NCT1008
   * Maxim MAX6646
     Prefix: 'max6646'
     Addresses scanned: I2C 0x4d
@@ -149,7 +159,7 @@ ADM1032:
   * ALERT is triggered by open remote sensor.
   * SMBus PEC support for Write Byte and Receive Byte transactions.
 
-ADT7461:
+ADT7461, ADT7461A, NCT1008:
   * Extended temperature range (breaks compatibility)
   * Lower resolution for remote temperature
 
@@ -205,11 +215,12 @@ SMBus Alert Support
 This driver has basic support for SMBus alert. When an alert is received,
 the status register is read and the faulty temperature channel is logged.
 
-The Analog Devices chips (ADM1032 and ADT7461) do not implement the SMBus
-alert protocol properly so additional care is needed: the ALERT output is
-disabled when an alert is received, and is re-enabled only when the alarm
-is gone. Otherwise the chip would block alerts from other chips in the bus
-as long as the alarm is active.
+The Analog Devices chips (ADM1032, ADT7461 and ADT7461A) and ON
+Semiconductor chips (NCT1008) do not implement the SMBus alert protocol
+properly so additional care is needed: the ALERT output is disabled when
+an alert is received, and is re-enabled only when the alarm is gone.
+Otherwise the chip would block alerts from other chips in the bus as long
+as the alarm is active.
 
 PEC Support
 -----------

drivers/hwmon/Kconfig

@@ -618,10 +618,10 @@ config SENSORS_LM90
 	depends on I2C
 	help
 	  If you say yes here you get support for National Semiconductor LM90,
-	  LM86, LM89 and LM99, Analog Devices ADM1032 and ADT7461, Maxim
-	  MAX6646, MAX6647, MAX6648, MAX6649, MAX6657, MAX6658, MAX6659,
-	  MAX6680, MAX6681, MAX6692, MAX6695, MAX6696, and Winbond/Nuvoton
-	  W83L771W/G/AWG/ASG sensor chips.
+	  LM86, LM89 and LM99, Analog Devices ADM1032, ADT7461, and ADT7461A,
+	  Maxim MAX6646, MAX6647, MAX6648, MAX6649, MAX6657, MAX6658, MAX6659,
+	  MAX6680, MAX6681, MAX6692, MAX6695, MAX6696, ON Semiconductor NCT1008,
+	  and Winbond/Nuvoton W83L771W/G/AWG/ASG sensor chips.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called lm90.

drivers/hwmon/lm90.c

@@ -49,10 +49,10 @@
  * chips, but support three temperature sensors instead of two. MAX6695
  * and MAX6696 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.
+ * This driver also supports ADT7461 and ADT7461A from Analog Devices as well as
+ * NCT1008 from ON Semiconductor. The chips are supported in both compatibility
+ * and extended mode. They are 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
@@ -88,9 +88,10 @@
  * 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, MAX6649, MAX6657,
- * MAX6658 and W83L771 have address 0x4c.
- * ADM1032-2, ADT7461-2, LM89-1, LM99-1 and MAX6646 have address 0x4d.
+ * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, ADT7461A, MAX6649,
+ * MAX6657, MAX6658, NCT1008 and W83L771 have address 0x4c.
+ * ADM1032-2, ADT7461-2, ADT7461A-2, LM89-1, LM99-1, MAX6646, and NCT1008D
+ * have address 0x4d.
  * MAX6647 has address 0x4e.
  * MAX6659 can have address 0x4c, 0x4d or 0x4e.
  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
@@ -174,6 +175,7 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
 static const struct i2c_device_id lm90_id[] = {
 	{ "adm1032", adm1032 },
 	{ "adt7461", adt7461 },
+	{ "adt7461a", adt7461 },
 	{ "lm90", lm90 },
 	{ "lm86", lm86 },
 	{ "lm89", lm86 },
@@ -188,6 +190,7 @@ static const struct i2c_device_id lm90_id[] = {
 	{ "max6681", max6680 },
 	{ "max6695", max6696 },
 	{ "max6696", max6696 },
+	{ "nct1008", adt7461 },
 	{ "w83l771", w83l771 },
 	{ }
 };
@@ -1153,6 +1156,11 @@ static int lm90_detect(struct i2c_client *new_client,
 		 && (reg_config1 & 0x1B) == 0x00
 		 && reg_convrate <= 0x0A) {
 			name = "adt7461";
+		} else
+		if (chip_id == 0x57 /* ADT7461A, NCT1008 */
+		 && (reg_config1 & 0x1B) == 0x00
+		 && reg_convrate <= 0x0A) {
+			name = "adt7461a";
 		}
 	} else
 	if (man_id == 0x4D) { /* Maxim */