hwmon: (it87) Add support for IT8790E

IT8790E is a super-IO chip with three fan tachometers. It is mostly
compatible to IT8728F, but only supports three fan tachometers
instead of five.
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/it87

@@ -58,6 +58,10 @@ Supported chips:
     Prefix: 'it8786'
     Addresses scanned: from Super I/O config space (8 I/O ports)
     Datasheet: Not publicly available
+  * IT8790E
+    Prefix: 'it8790'
+    Addresses scanned: from Super I/O config space (8 I/O ports)
+    Datasheet: Not publicly available
   * SiS950   [clone of IT8705F]
     Prefix: 'it87'
     Addresses scanned: from Super I/O config space (8 I/O ports)
@@ -102,9 +106,10 @@ motherboard models.
 Description
 -----------
 
-This driver implements support for the IT8603E, IT8623E, IT8705F, IT8712F,
-IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E, IT8771E,
-IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, and SiS950 chips.
+This driver implements support for the IT8603E, IT8623E, IT8705F,
+IT8712F, IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E,
+IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E, and SiS950
+chips.
 
 These chips are 'Super I/O chips', supporting floppy disks, infrared ports,
 joysticks and other miscellaneous stuff. For hardware monitoring, they
@@ -145,6 +150,8 @@ The IT8603E/IT8623E is a custom design, hardware monitoring part is similar to
 IT8728F. It only supports 16-bit fan mode, the full speed mode of the
 fan is not supported (value 0 of pwmX_enable).
 
+The IT8790E supports up to 3 fans. 16-bit fan mode is always enabled.
+
 Temperatures are measured in degrees Celsius. An alarm is triggered once
 when the Overtemperature Shutdown limit is crossed.
 

drivers/hwmon/Kconfig

@@ -600,8 +600,8 @@ config SENSORS_IT87
 	help
 	  If you say yes here you get support for ITE IT8705F, IT8712F,
 	  IT8716F, IT8718F, IT8720F, IT8721F, IT8726F, IT8728F, IT8758E,
-	  IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E,
-	  and IT8603E sensor chips, and the SiS950 clone.
+	  IT8771E, IT8772E, IT8781F, IT8782F, IT8783E/F, IT8786E, IT8790E,
+	  IT8603E, and IT8623E sensor chips, and the SiS950 clone.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called it87.

drivers/hwmon/it87.c

@@ -27,6 +27,7 @@
  *            IT8782F  Super I/O chip w/LPC interface
  *            IT8783E/F Super I/O chip w/LPC interface
  *            IT8786E  Super I/O chip w/LPC interface
+ *            IT8790E  Super I/O chip w/LPC interface
  *            Sis950   A clone of the IT8705F
  *
  *  Copyright (C) 2001 Chris Gauthron
@@ -68,7 +69,7 @@
 #define DRVNAME "it87"
 
 enum chips { it87, it8712, it8716, it8718, it8720, it8721, it8728, it8771,
-	     it8772, it8781, it8782, it8783, it8786, it8603 };
+	     it8772, it8781, it8782, it8783, it8786, it8790, it8603 };
 
 static unsigned short force_id;
 module_param(force_id, ushort, 0);
@@ -152,6 +153,7 @@ static inline void superio_exit(void)
 #define IT8782F_DEVID 0x8782
 #define IT8783E_DEVID 0x8783
 #define IT8786E_DEVID 0x8786
+#define IT8790E_DEVID 0x8790
 #define IT8603E_DEVID 0x8603
 #define IT8623E_DEVID 0x8623
 #define IT87_ACT_REG  0x30
@@ -359,6 +361,13 @@ static const struct it87_devices it87_devices[] = {
 		  | FEAT_TEMP_OFFSET | FEAT_TEMP_PECI | FEAT_IN7_INTERNAL,
 		.peci_mask = 0x07,
 	},
+	[it8790] = {
+		.name = "it8790",
+		.suffix = "E",
+		.features = FEAT_NEWER_AUTOPWM | FEAT_12MV_ADC | FEAT_16BIT_FANS
+		  | FEAT_TEMP_OFFSET | FEAT_TEMP_PECI | FEAT_IN7_INTERNAL,
+		.peci_mask = 0x07,
+	},
 	[it8603] = {
 		.name = "it8603",
 		.suffix = "E",
@@ -1834,6 +1843,9 @@ static int __init it87_find(unsigned short *address,
 	case IT8786E_DEVID:
 		sio_data->type = it8786;
 		break;
+	case IT8790E_DEVID:
+		sio_data->type = it8790;
+		break;
 	case IT8603E_DEVID:
 	case IT8623E_DEVID:
 		sio_data->type = it8603;