diff --git a/sound/aoa/core/snd-aoa-gpio-feature.c b/sound/aoa/core/snd-aoa-gpio-feature.c
index 7ae0c0b..2ab5533 100644
--- a/sound/aoa/core/snd-aoa-gpio-feature.c
+++ b/sound/aoa/core/snd-aoa-gpio-feature.c
@@ -56,7 +56,7 @@
 {
 	struct device_node *np, *gpio;
 	u32 *reg;
-	char *audio_gpio;
+	const char *audio_gpio;
 
 	*gpioptr = -1;
 
diff --git a/sound/oss/dmasound/dmasound_awacs.c b/sound/oss/dmasound/dmasound_awacs.c
index 4359903..9ae659f 100644
--- a/sound/oss/dmasound/dmasound_awacs.c
+++ b/sound/oss/dmasound/dmasound_awacs.c
@@ -347,8 +347,8 @@
 setup_audio_gpio(const char *name, const char* compatible, int *gpio_addr, int* gpio_pol)
 {
 	struct device_node *np;
-	u32* pp;
-	
+	const u32* pp;
+
 	np = find_devices("gpio");
 	if (!np)
 		return -ENODEV;
@@ -356,7 +356,8 @@
 	np = np->child;
 	while(np != 0) {
 		if (name) {
-			char *property = get_property(np,"audio-gpio",NULL);
+			const char *property =
+				get_property(np,"audio-gpio",NULL);
 			if (property != 0 && strcmp(property,name) == 0)
 				break;
 		} else if (compatible && device_is_compatible(np, compatible))
@@ -365,11 +366,11 @@
 	}
 	if (!np)
 		return -ENODEV;
-	pp = (u32 *)get_property(np, "AAPL,address", NULL);
+	pp = get_property(np, "AAPL,address", NULL);
 	if (!pp)
 		return -ENODEV;
 	*gpio_addr = (*pp) & 0x0000ffff;
-	pp = (u32 *)get_property(np, "audio-gpio-active-state", NULL);
+	pp = get_property(np, "audio-gpio-active-state", NULL);
 	if (pp)
 		*gpio_pol = *pp;
 	else
diff --git a/sound/ppc/tumbler.c b/sound/ppc/tumbler.c
index 692c611..b94ecd0 100644
--- a/sound/ppc/tumbler.c
+++ b/sound/ppc/tumbler.c
@@ -1035,7 +1035,7 @@
 		return NULL;
   
 	for (np = np->child; np; np = np->sibling) {
-		char *property = get_property(np, "audio-gpio", NULL);
+		const char *property = get_property(np, "audio-gpio", NULL);
 		if (property && strcmp(property, name) == 0)
 			return np;
 	}  
@@ -1062,7 +1062,8 @@
 				struct pmac_gpio *gp, int is_compatible)
 {
 	struct device_node *node;
-	u32 *base, addr;
+	const u32 *base;
+	u32 addr;
 
 	if (is_compatible)
 		node = find_compatible_audio_device(device);
@@ -1074,9 +1075,9 @@
 		return -ENODEV;
 	}
 
-	base = (u32 *)get_property(node, "AAPL,address", NULL);
+	base = get_property(node, "AAPL,address", NULL);
 	if (! base) {
-		base = (u32 *)get_property(node, "reg", NULL);
+		base = get_property(node, "reg", NULL);
 		if (!base) {
 			DBG("(E) cannot find address for device %s !\n", device);
 			snd_printd("cannot find address for device %s\n", device);
@@ -1090,13 +1091,13 @@
 
 	gp->addr = addr & 0x0000ffff;
 	/* Try to find the active state, default to 0 ! */
-	base = (u32 *)get_property(node, "audio-gpio-active-state", NULL);
+	base = get_property(node, "audio-gpio-active-state", NULL);
 	if (base) {
 		gp->active_state = *base;
 		gp->active_val = (*base) ? 0x5 : 0x4;
 		gp->inactive_val = (*base) ? 0x4 : 0x5;
 	} else {
-		u32 *prop = NULL;
+		const u32 *prop = NULL;
 		gp->active_state = 0;
 		gp->active_val = 0x4;
 		gp->inactive_val = 0x5;
@@ -1105,7 +1106,7 @@
 		 * as we don't yet have an interpreter for these things
 		 */
 		if (platform)
-			prop = (u32 *)get_property(node, platform, NULL);
+			prop = get_property(node, platform, NULL);
 		if (prop) {
 			if (prop[3] == 0x9 && prop[4] == 0x9) {
 				gp->active_val = 0xd;