hwmon: (it87) Add feature flag for VID support

Newer chips don't typically support VID inputs or control.
Add a feature flag for VID support to simplify adding support for
new chips.
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/it87.c

@@ -254,6 +254,7 @@ struct it87_devices {
 #define FEAT_TEMP_OLD_PECI	(1 << 6)
 #define FEAT_FAN16_CONFIG	(1 << 7)	/* Need to enable 16-bit fans */
 #define FEAT_FIVE_FANS		(1 << 8)	/* Supports five fans */
+#define FEAT_VID		(1 << 9)	/* Set if chip supports VID */
 
 static const struct it87_devices it87_devices[] = {
 	[it87] = {
@@ -262,22 +263,23 @@ static const struct it87_devices it87_devices[] = {
 	},
 	[it8712] = {
 		.name = "it8712",
-		.features = FEAT_OLD_AUTOPWM,	/* may need to overwrite */
+		.features = FEAT_OLD_AUTOPWM | FEAT_VID,
+						/* may need to overwrite */
 	},
 	[it8716] = {
 		.name = "it8716",
-		.features = FEAT_16BIT_FANS | FEAT_TEMP_OFFSET
+		.features = FEAT_16BIT_FANS | FEAT_TEMP_OFFSET | FEAT_VID
 		  | FEAT_FAN16_CONFIG | FEAT_FIVE_FANS,
 	},
 	[it8718] = {
 		.name = "it8718",
-		.features = FEAT_16BIT_FANS | FEAT_TEMP_OFFSET
+		.features = FEAT_16BIT_FANS | FEAT_TEMP_OFFSET | FEAT_VID
 		  | FEAT_TEMP_OLD_PECI | FEAT_FAN16_CONFIG | FEAT_FIVE_FANS,
 		.old_peci_mask = 0x4,
 	},
 	[it8720] = {
 		.name = "it8720",
-		.features = FEAT_16BIT_FANS | FEAT_TEMP_OFFSET
+		.features = FEAT_16BIT_FANS | FEAT_TEMP_OFFSET | FEAT_VID
 		  | FEAT_TEMP_OLD_PECI | FEAT_FAN16_CONFIG | FEAT_FIVE_FANS,
 		.old_peci_mask = 0x4,
 	},
@@ -353,6 +355,7 @@ static const struct it87_devices it87_devices[] = {
 				 ((data)->old_peci_mask & (1 << nr)))
 #define has_fan16_config(data)	((data)->features & FEAT_FAN16_CONFIG)
 #define has_five_fans(data)	((data)->features & FEAT_FIVE_FANS)
+#define has_vid(data)		((data)->features & FEAT_VID)
 
 struct it87_sio_data {
 	enum chips type;
@@ -1822,19 +1825,17 @@ static int __init it87_find(unsigned short *address,
 	if (sio_data->type != it8603)
 		sio_data->skip_in |= (1 << 9);
 
-	/* Read GPIO config and VID value from LDN 7 (GPIO) */
-	if (sio_data->type == it87) {
-		/* The IT8705F doesn't have VID pins at all */
+	if (!(it87_devices[sio_data->type].features & FEAT_VID))
 		sio_data->skip_vid = 1;
 
+	/* Read GPIO config and VID value from LDN 7 (GPIO) */
+	if (sio_data->type == it87) {
 		/* The IT8705F has a different LD number for GPIO */
 		superio_select(5);
 		sio_data->beep_pin = superio_inb(IT87_SIO_BEEP_PIN_REG) & 0x3f;
 	} else if (sio_data->type == it8783) {
 		int reg25, reg27, reg2a, reg2c, regef;
 
-		sio_data->skip_vid = 1;	/* No VID */
-
 		superio_select(GPIO);
 
 		reg25 = superio_inb(IT87_SIO_GPIO1_REG);
@@ -1900,7 +1901,6 @@ static int __init it87_find(unsigned short *address,
 	} else if (sio_data->type == it8603) {
 		int reg27, reg29;
 
-		sio_data->skip_vid = 1;	/* No VID */
 		superio_select(GPIO);
 
 		reg27 = superio_inb(IT87_SIO_GPIO3_REG);
@@ -1936,16 +1936,7 @@ static int __init it87_find(unsigned short *address,
 		superio_select(GPIO);
 
 		reg = superio_inb(IT87_SIO_GPIO3_REG);
-		if (sio_data->type == it8721 || sio_data->type == it8728 ||
-		    sio_data->type == it8771 || sio_data->type == it8772 ||
-		    sio_data->type == it8781 || sio_data->type == it8782) {
-			/*
-			 * IT8721F/IT8758E, IT8728F, IT8772F, IT8781F, and
-			 * IT8782F don't have VID pins at all, not sure about
-			 * the IT8771F.
-			 */
-			sio_data->skip_vid = 1;
-		} else {
+		if (!sio_data->skip_vid) {
 			/* We need at least 4 VID pins */
 			if (reg & 0x0f) {
 				pr_info("VID is disabled (pins used for GPIO)\n");