ALSA: powermac - Reverse HP detection on G4 DA

Reverse headphone detection bit on PowerMac G4 Digital Audio (Tumbler).
Signed-off-by: Risto Suominen <Risto.Suominen@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/ppc/tumbler.c

@@ -30,6 +30,7 @@
 #include <linux/kmod.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
+#include <linux/string.h>
 #include <sound/core.h>
 #include <asm/io.h>
 #include <asm/irq.h>
@@ -46,6 +47,8 @@
 #define DBG(fmt...)
 #endif
 
+#define IS_G4DA (machine_is_compatible("PowerMac3,4"))
+
 /* i2c address for tumbler */
 #define TAS_I2C_ADDR	0x34
 
@@ -1134,7 +1137,7 @@ static long tumbler_find_device(const char *device, const char *platform,
 		gp->inactive_val = (*base) ? 0x4 : 0x5;
 	} else {
 		const u32 *prop = NULL;
-		gp->active_state = 0;
+		gp->active_state = IS_G4DA && !strcmp(device, "keywest-gpio15");
 		gp->active_val = 0x4;
 		gp->inactive_val = 0x5;
 		/* Here are some crude hacks to extract the GPIO polarity and