acpi_apple: make the device mode a typed enum

The two mode values were spelled as bit flags, but a device is exactly
one of the two and the dispatch compared the field for equality.

Turned them into an enum, type the softc field with it, and dispatch with
a switch that lists every value

No functional change.

Reviewed by:	adrian
Differential Revision:	https://reviews.freebsd.org/D60793

sys/dev/acpi_apple/acpi_apple.c

@@ -77,10 +77,13 @@ acpi_apple_attach(device_t dev)
 	else
 		sc->mode = ACPI_APPLE_PLATFORM;
 
-	if (sc->mode == ACPI_APPLE_PLATFORM)
+	switch (sc->mode) {
+	case ACPI_APPLE_PLATFORM:
 		return (acpi_apple_platform_attach(sc));
-	else
+	case ACPI_APPLE_BACKLIGHT:
 		return (acpi_apple_backlight_attach(sc));
+	}
+	return (ENXIO);
 }
 
 static int
@@ -89,10 +92,14 @@ acpi_apple_detach(device_t dev)
 	struct acpi_apple_softc *sc;
 
 	sc = device_get_softc(dev);
-	if (sc->mode == ACPI_APPLE_PLATFORM)
+	switch (sc->mode) {
+	case ACPI_APPLE_PLATFORM:
 		acpi_apple_platform_detach(sc);
-	else
+		break;
+	case ACPI_APPLE_BACKLIGHT:
 		acpi_apple_backlight_detach(sc);
+		break;
+	}
 	return (0);
 }
 

sys/dev/acpi_apple/acpi_apple.h

@@ -21,8 +21,10 @@
 #include <dev/acpica/acpivar.h>
 #include <dev/backlight/backlight.h>
 
-#define	ACPI_APPLE_PLATFORM	0x01	/* WoL + lid (APP000B/APP9876) */
-#define	ACPI_APPLE_BACKLIGHT	0x02	/* panel backlight (APP0002) */
+enum acpi_apple_mode {
+	ACPI_APPLE_PLATFORM,		/* WoL + lid (APP000B/APP9876) */
+	ACPI_APPLE_BACKLIGHT,		/* panel backlight (APP0002) */
+};
 
 /*
  * Apple GMUX (GPU multiplexer) registers.
@@ -116,7 +118,7 @@ struct apple_bl_hw {
 struct acpi_apple_softc {
 	device_t		dev;
 	ACPI_HANDLE		handle;
-	int			mode;
+	enum acpi_apple_mode	mode;
 
 	/* Backlight */
 	struct mtx		bl_mtx;		/* protects hw access + cache */