hwmon: (it87) Add support for the ITE IT8720F

Allow it87.c to handle IT8720 chipset like IT8718 in order to
retrieve voltage, temperatures and fans speed from sensors
tools. Also updating the related documentation.

Signed-off-by: Jean-Marc Spaggiari <jean-marc@spaggiari.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/Documentation/hwmon/it87 b/Documentation/hwmon/it87
index 042c041..659315d 100644
--- a/Documentation/hwmon/it87
+++ b/Documentation/hwmon/it87
@@ -26,6 +26,10 @@
     Datasheet: Publicly available at the ITE website
                http://www.ite.com.tw/product_info/file/pc/IT8718F_V0.2.zip
                http://www.ite.com.tw/product_info/file/pc/IT8718F_V0%203_(for%20C%20version).zip
+  * IT8720F
+    Prefix: 'it8720'
+    Addresses scanned: from Super I/O config space (8 I/O ports)
+    Datasheet: Not yet publicly available.
   * SiS950   [clone of IT8705F]
     Prefix: 'it87'
     Addresses scanned: from Super I/O config space (8 I/O ports)
@@ -71,7 +75,7 @@
 -----------
 
 This driver implements support for the IT8705F, IT8712F, IT8716F,
-IT8718F, IT8726F and SiS950 chips.
+IT8718F, IT8720F, IT8726F and SiS950 chips.
 
 These chips are 'Super I/O chips', supporting floppy disks, infrared ports,
 joysticks and other miscellaneous stuff. For hardware monitoring, they
@@ -84,19 +88,19 @@
 though, so the functionality may not be available on a given system.
 The driver dumbly assume it is there.
 
-The IT8718F also features VID inputs (up to 8 pins) but the value is
-stored in the Super-I/O configuration space. Due to technical limitations,
+The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value
+is stored in the Super-I/O configuration space. Due to technical limitations,
 this value can currently only be read once at initialization time, so
 the driver won't notice and report changes in the VID value. The two
 upper VID bits share their pins with voltage inputs (in5 and in6) so you
 can't have both on a given board.
 
-The IT8716F, IT8718F and later IT8712F revisions have support for
+The IT8716F, IT8718F, IT8720F and later IT8712F revisions have support for
 2 additional fans. The additional fans are supported by the driver.
 
-The IT8716F and IT8718F, and late IT8712F and IT8705F also have optional
-16-bit tachometer counters for fans 1 to 3. This is better (no more fan
-clock divider mess) but not compatible with the older chips and
+The IT8716F, IT8718F and IT8720F, and late IT8712F and IT8705F also have
+optional 16-bit tachometer counters for fans 1 to 3. This is better (no more
+fan clock divider mess) but not compatible with the older chips and
 revisions. The 16-bit tachometer mode is enabled by the driver when one
 of the above chips is detected.
 
@@ -122,7 +126,7 @@
 inputs can measure voltages between 0 and 4.08 volts, with a resolution of
 0.016 volt. The battery voltage in8 does not have limit registers.
 
-The VID lines (IT8712F/IT8716F/IT8718F) encode the core voltage value:
+The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value:
 the voltage level your processor should work with. This is hardcoded by
 the mainboard and/or processor itself. It is a value in volts.
 
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 1ef1205..aba01b4 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -400,7 +400,8 @@
 	select HWMON_VID
 	help
 	  If you say yes here you get support for ITE IT8705F, IT8712F,
-	  IT8716F, IT8718F and IT8726F sensor chips, and the SiS960 clone.
+	  IT8716F, IT8718F, IT8720F and IT8726F sensor chips, and the
+	  SiS960 clone.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called it87.
diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index b74c957..0e0d692 100644
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -14,6 +14,7 @@
               IT8712F  Super I/O chip w/LPC interface
               IT8716F  Super I/O chip w/LPC interface
               IT8718F  Super I/O chip w/LPC interface
+              IT8720F  Super I/O chip w/LPC interface
               IT8726F  Super I/O chip w/LPC interface
               Sis950   A clone of the IT8705F
 
@@ -52,7 +53,7 @@
 
 #define DRVNAME "it87"
 
-enum chips { it87, it8712, it8716, it8718 };
+enum chips { it87, it8712, it8716, it8718, it8720 };
 
 static unsigned short force_id;
 module_param(force_id, ushort, 0);
@@ -64,7 +65,10 @@
 #define	DEV	0x07	/* Register: Logical device select */
 #define	VAL	0x2f	/* The value to read/write */
 #define PME	0x04	/* The device with the fan registers in it */
-#define GPIO	0x07	/* The device with the IT8718F VID value in it */
+
+/* The device with the IT8718F/IT8720F VID value in it */
+#define GPIO	0x07
+
 #define	DEVID	0x20	/* Register: Device ID */
 #define	DEVREV	0x22	/* Register: Device Revision */
 
@@ -113,6 +117,7 @@
 #define IT8705F_DEVID 0x8705
 #define IT8716F_DEVID 0x8716
 #define IT8718F_DEVID 0x8718
+#define IT8720F_DEVID 0x8720
 #define IT8726F_DEVID 0x8726
 #define IT87_ACT_REG  0x30
 #define IT87_BASE_REG 0x60
@@ -150,8 +155,8 @@
 #define IT87_REG_ALARM2        0x02
 #define IT87_REG_ALARM3        0x03
 
-/* The IT8718F has the VID value in a different register, in Super-I/O
-   configuration space. */
+/* The IT8718F and IT8720F have the VID value in a different register, in
+   Super-I/O configuration space. */
 #define IT87_REG_VID           0x0a
 /* The IT8705F and IT8712F earlier than revision 0x08 use register 0x0b
    for fan divisors. Later IT8712F revisions must use 16-bit tachometer
@@ -282,7 +287,8 @@
 	return (data->type == it87 && data->revision >= 0x03)
 	    || (data->type == it8712 && data->revision >= 0x08)
 	    || data->type == it8716
-	    || data->type == it8718;
+	    || data->type == it8718
+	    || data->type == it8720;
 }
 
 static int it87_probe(struct platform_device *pdev);
@@ -992,6 +998,9 @@
 	case IT8718F_DEVID:
 		sio_data->type = it8718;
 		break;
+	case IT8720F_DEVID:
+		sio_data->type = it8720;
+		break;
 	case 0xffff:	/* No device at all */
 		goto exit;
 	default:
@@ -1022,7 +1031,8 @@
 		int reg;
 
 		superio_select(GPIO);
-		if (chip_type == it8718)
+		if ((chip_type == it8718) ||
+		    (chip_type == it8720))
 			sio_data->vid_value = superio_inb(IT87_SIO_VID_REG);
 
 		reg = superio_inb(IT87_SIO_PINX2_REG);
@@ -1068,6 +1078,7 @@
 		"it8712",
 		"it8716",
 		"it8718",
+		"it8720",
 	};
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
@@ -1226,7 +1237,7 @@
 	}
 
 	if (data->type == it8712 || data->type == it8716
-	 || data->type == it8718) {
+	 || data->type == it8718 || data->type == it8720) {
 		data->vrm = vid_which_vrm();
 		/* VID reading from Super-I/O config space if available */
 		data->vid = sio_data->vid_value;
@@ -1513,7 +1524,8 @@
 
 		data->sensor = it87_read_value(data, IT87_REG_TEMP_ENABLE);
 		/* The 8705 does not have VID capability.
-		   The 8718 does not use IT87_REG_VID for the same purpose. */
+		   The 8718 and the 8720 don't use IT87_REG_VID for the
+		   same purpose. */
 		if (data->type == it8712 || data->type == it8716) {
 			data->vid = it87_read_value(data, IT87_REG_VID);
 			/* The older IT8712F revisions had only 5 VID pins,
@@ -1608,7 +1620,7 @@
 
 MODULE_AUTHOR("Chris Gauthron, "
 	      "Jean Delvare <khali@linux-fr.org>");
-MODULE_DESCRIPTION("IT8705F/8712F/8716F/8718F/8726F, SiS950 driver");
+MODULE_DESCRIPTION("IT8705F/8712F/8716F/8718F/8720F/8726F, SiS950 driver");
 module_param(update_vbat, bool, 0);
 MODULE_PARM_DESC(update_vbat, "Update vbat if set else return powerup value");
 module_param(fix_pwm_polarity, bool, 0);