diff --git a/drivers/i2c/busses/i2c-powermac.c b/drivers/i2c/busses/i2c-powermac.c
index 2a0b3be..e8a6de5 100644
--- a/drivers/i2c/busses/i2c-powermac.c
+++ b/drivers/i2c/busses/i2c-powermac.c
@@ -209,7 +209,8 @@
 	struct pmac_i2c_bus *bus = dev->platform_data;
 	struct device_node *parent = NULL;
 	struct i2c_adapter *adapter;
-	char name[32], *basename;
+	char name[32];
+	const char *basename;
 	int rc;
 
 	if (bus == NULL)
diff --git a/drivers/ide/ppc/pmac.c b/drivers/ide/ppc/pmac.c
index ebf961f..fa46856 100644
--- a/drivers/ide/ppc/pmac.c
+++ b/drivers/ide/ppc/pmac.c
@@ -1154,7 +1154,7 @@
 pmac_ide_setup_device(pmac_ide_hwif_t *pmif, ide_hwif_t *hwif)
 {
 	struct device_node *np = pmif->node;
-	int *bidp;
+	const int *bidp;
 
 	pmif->cable_80 = 0;
 	pmif->broken_dma = pmif->broken_dma_warn = 0;
@@ -1176,14 +1176,14 @@
 		pmif->broken_dma = 1;
 	}
 
-	bidp = (int *)get_property(np, "AAPL,bus-id", NULL);
+	bidp = get_property(np, "AAPL,bus-id", NULL);
 	pmif->aapl_bus_id =  bidp ? *bidp : 0;
 
 	/* Get cable type from device-tree */
 	if (pmif->kind == controller_kl_ata4 || pmif->kind == controller_un_ata6
 	    || pmif->kind == controller_k2_ata6
 	    || pmif->kind == controller_sh_ata6) {
-		char* cable = get_property(np, "cable-type", NULL);
+		const char* cable = get_property(np, "cable-type", NULL);
 		if (cable && !strncmp(cable, "80-", 3))
 			pmif->cable_80 = 1;
 	}
diff --git a/drivers/macintosh/macio_asic.c b/drivers/macintosh/macio_asic.c
index 80c0c66..7817cf2 100644
--- a/drivers/macintosh/macio_asic.c
+++ b/drivers/macintosh/macio_asic.c
@@ -139,7 +139,9 @@
 {
 	struct macio_dev * macio_dev;
 	struct of_device * of;
-	char *scratch, *compat, *compat2;
+	char *scratch;
+	const char *compat, *compat2;
+
 	int i = 0;
 	int length, cplen, cplen2, seen = 0;
 
@@ -173,7 +175,7 @@
          * it's not really legal to split it out with commas. We split it
          * up using a number of environment variables instead. */
 
-	compat = (char *) get_property(of->node, "compatible", &cplen);
+	compat = get_property(of->node, "compatible", &cplen);
 	compat2 = compat;
 	cplen2= cplen;
 	while (compat && cplen > 0) {
@@ -454,7 +456,7 @@
 					       struct resource *parent_res)
 {
 	struct macio_dev *dev;
-	u32 *reg;
+	const u32 *reg;
 	
 	if (np == NULL)
 		return NULL;
@@ -489,7 +491,7 @@
 #endif
 			MAX_NODE_NAME_SIZE, np->name);
 	} else {
-		reg = (u32 *)get_property(np, "reg", NULL);
+		reg = get_property(np, "reg", NULL);
 		sprintf(dev->ofdev.dev.bus_id, "%1d.%08x:%.*s",
 			chip->lbus.index,
 			reg ? *reg : 0, MAX_NODE_NAME_SIZE, np->name);
diff --git a/drivers/macintosh/macio_sysfs.c b/drivers/macintosh/macio_sysfs.c
index cae24a1..8566bdf 100644
--- a/drivers/macintosh/macio_sysfs.c
+++ b/drivers/macintosh/macio_sysfs.c
@@ -16,12 +16,12 @@
 compatible_show (struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct of_device *of;
-	char *compat;
+	const char *compat;
 	int cplen;
 	int length = 0;
 
 	of = &to_macio_device (dev)->ofdev;
-	compat = (char *) get_property(of->node, "compatible", &cplen);
+	compat = get_property(of->node, "compatible", &cplen);
 	if (!compat) {
 		*buf = '\0';
 		return 0;
@@ -42,12 +42,12 @@
 			      char *buf)
 {
 	struct of_device *of;
-	char *compat;
+	const char *compat;
 	int cplen;
 	int length;
 
 	of = &to_macio_device (dev)->ofdev;
-	compat = (char *) get_property (of->node, "compatible", &cplen);
+	compat = get_property(of->node, "compatible", &cplen);
 	if (!compat) compat = "", cplen = 1;
 	length = sprintf (buf, "of:N%sT%s", of->node->name, of->node->type);
 	buf += length;
diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index f139a74..6f35860 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -447,7 +447,7 @@
 int __init smu_init (void)
 {
 	struct device_node *np;
-	u32 *data;
+	const u32 *data;
 
         np = of_find_node_by_type(NULL, "smu");
         if (np == NULL)
@@ -483,7 +483,7 @@
 		printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 		goto fail;
 	}
-	data = (u32 *)get_property(np, "reg", NULL);
+	data = get_property(np, "reg", NULL);
 	if (data == NULL) {
 		of_node_put(np);
 		printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
@@ -506,7 +506,7 @@
 		np = of_find_node_by_name(NULL, "smu-interrupt");
 		if (np == NULL)
 			break;
-		data = (u32 *)get_property(np, "reg", NULL);
+		data = get_property(np, "reg", NULL);
 		if (data == NULL) {
 			of_node_put(np);
 			break;
@@ -959,11 +959,11 @@
 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
  * when interruptible is 1
  */
-struct smu_sdbp_header *__smu_get_sdb_partition(int id, unsigned int *size,
-						int interruptible)
+const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
+		unsigned int *size, int interruptible)
 {
 	char pname[32];
-	struct smu_sdbp_header *part;
+	const struct smu_sdbp_header *part;
 
 	if (!smu)
 		return NULL;
@@ -980,8 +980,7 @@
 	} else
 		mutex_lock(&smu_part_access);
 
-	part = (struct smu_sdbp_header *)get_property(smu->of_node,
-						      pname, size);
+	part = get_property(smu->of_node, pname, size);
 	if (part == NULL) {
 		DPRINTK("trying to extract from SMU ...\n");
 		part = smu_create_sdb_partition(id);
@@ -992,7 +991,7 @@
 	return part;
 }
 
-struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
+const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
 {
 	return __smu_get_sdb_partition(id, size, 0);
 }
@@ -1071,7 +1070,7 @@
 		pp->mode = smu_file_events;
 		return 0;
 	} else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
-		struct smu_sdbp_header *part;
+		const struct smu_sdbp_header *part;
 		part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
 		if (part == NULL)
 			return -EINVAL;
diff --git a/drivers/macintosh/therm_adt746x.c b/drivers/macintosh/therm_adt746x.c
index 7f86478..a0f30d0 100644
--- a/drivers/macintosh/therm_adt746x.c
+++ b/drivers/macintosh/therm_adt746x.c
@@ -47,7 +47,7 @@
 
 static u8 default_limits_local[3] = {70, 50, 70};    /* local, sensor1, sensor2 */
 static u8 default_limits_chip[3] = {80, 65, 80};    /* local, sensor1, sensor2 */
-static char *sensor_location[3] = {NULL, NULL, NULL};
+static const char *sensor_location[3] = {NULL, NULL, NULL};
 
 static int limit_adjust = 0;
 static int fan_speed = -1;
@@ -553,7 +553,7 @@
 thermostat_init(void)
 {
 	struct device_node* np;
-	u32 *prop;
+	const u32 *prop;
 	int i = 0, offset = 0;
 	
 	np = of_find_node_by_name(NULL, "fan");
@@ -566,13 +566,13 @@
 	else
 		return -ENODEV;
 
-	prop = (u32 *)get_property(np, "hwsensor-params-version", NULL);
+	prop = get_property(np, "hwsensor-params-version", NULL);
 	printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
 			 (*prop == 1)?"":"un");
 	if (*prop != 1)
 		return -ENODEV;
 
-	prop = (u32 *)get_property(np, "reg", NULL);
+	prop = get_property(np, "reg", NULL);
 	if (!prop)
 		return -ENODEV;
 
diff --git a/drivers/macintosh/therm_pm72.c b/drivers/macintosh/therm_pm72.c
index 20bf672..d00c0c3 100644
--- a/drivers/macintosh/therm_pm72.c
+++ b/drivers/macintosh/therm_pm72.c
@@ -660,7 +660,7 @@
 {
 	struct device_node *np;
 	char nodename[64];
-	u8 *data;
+	const u8 *data;
 	int len;
 
 	/* prom.c routine for finding a node by path is a bit brain dead
@@ -673,7 +673,7 @@
 		printk(KERN_ERR "therm_pm72: Failed to retrieve cpuid node from device-tree\n");
 		return -ENODEV;
 	}
-	data = (u8 *)get_property(np, "cpuid", &len);
+	data = get_property(np, "cpuid", &len);
 	if (data == NULL) {
 		printk(KERN_ERR "therm_pm72: Failed to retrieve cpuid property from device-tree\n");
 		of_node_put(np);
@@ -1336,7 +1336,7 @@
 	 */
 	u3 = of_find_node_by_path("/u3@0,f8000000");
 	if (u3 != NULL) {
-		u32 *vers = (u32 *)get_property(u3, "device-rev", NULL);
+		const u32 *vers = get_property(u3, "device-rev", NULL);
 		if (vers)
 			if (((*vers) & 0x3f) < 0x34)
 				u3h = 0;
@@ -2111,8 +2111,8 @@
 
 	while ((np = of_get_next_child(fcu_node, np)) != NULL) {
 		int type = -1;
-		char *loc;
-		u32 *reg;
+		const char *loc;
+		const u32 *reg;
 
 		DBG(" control: %s, type: %s\n", np->name, np->type);
 
@@ -2128,8 +2128,8 @@
 			continue;
 
 		/* Lookup for a matching location */
-		loc = (char *)get_property(np, "location", NULL);
-		reg = (u32 *)get_property(np, "reg", NULL);
+		loc = get_property(np, "location", NULL);
+		reg = get_property(np, "reg", NULL);
 		if (loc == NULL || reg == NULL)
 			continue;
 		DBG(" matching location: %s, reg: 0x%08x\n", loc, *reg);
diff --git a/drivers/macintosh/therm_windtunnel.c b/drivers/macintosh/therm_windtunnel.c
index c7d1c29..738faab 100644
--- a/drivers/macintosh/therm_windtunnel.c
+++ b/drivers/macintosh/therm_windtunnel.c
@@ -484,14 +484,14 @@
 static int __init
 g4fan_init( void )
 {
-	struct apple_thermal_info *info;
+	const struct apple_thermal_info *info;
 	struct device_node *np;
 
 	init_MUTEX( &x.lock );
 
 	if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
 		return -ENODEV;
-	info = (struct apple_thermal_info*)get_property(np, "thermal-info", NULL);
+	info = get_property(np, "thermal-info", NULL);
 	of_node_put(np);
 
 	if( !info || !machine_is_compatible("PowerMac3,6") )
diff --git a/drivers/macintosh/via-cuda.c b/drivers/macintosh/via-cuda.c
index 69d5452..7512d1c 100644
--- a/drivers/macintosh/via-cuda.c
+++ b/drivers/macintosh/via-cuda.c
@@ -123,7 +123,7 @@
 {
     struct adb_request req;
     phys_addr_t taddr;
-    u32 *reg;
+    const u32 *reg;
     int err;
 
     if (vias != 0)
@@ -132,7 +132,7 @@
     if (vias == 0)
 	return 0;
 
-    reg = (u32 *)get_property(vias, "reg", NULL);
+    reg = get_property(vias, "reg", NULL);
     if (reg == NULL) {
 	    printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
 	    goto fail;
diff --git a/drivers/macintosh/via-pmu-led.c b/drivers/macintosh/via-pmu-led.c
index 5189d54..179af10 100644
--- a/drivers/macintosh/via-pmu-led.c
+++ b/drivers/macintosh/via-pmu-led.c
@@ -120,7 +120,7 @@
 	dt = of_find_node_by_path("/");
 	if (dt == NULL)
 		return -ENODEV;
-	model = (const char *)get_property(dt, "model", NULL);
+	model = get_property(dt, "model", NULL);
 	if (model == NULL)
 		return -ENODEV;
 	if (strncmp(model, "PowerBook", strlen("PowerBook")) != 0 &&
diff --git a/drivers/macintosh/via-pmu.c b/drivers/macintosh/via-pmu.c
index 06ca80b..80e88b4 100644
--- a/drivers/macintosh/via-pmu.c
+++ b/drivers/macintosh/via-pmu.c
@@ -287,7 +287,7 @@
 int __init find_via_pmu(void)
 {
 	u64 taddr;
-	u32 *reg;
+	const u32 *reg;
 
 	if (via != 0)
 		return 1;
@@ -295,7 +295,7 @@
 	if (vias == NULL)
 		return 0;
 
-	reg = (u32 *)get_property(vias, "reg", NULL);
+	reg = get_property(vias, "reg", NULL);
 	if (reg == NULL) {
 		printk(KERN_ERR "via-pmu: No \"reg\" property !\n");
 		goto fail;
@@ -337,7 +337,7 @@
 		
 		gpiop = of_find_node_by_name(NULL, "gpio");
 		if (gpiop) {
-			reg = (u32 *)get_property(gpiop, "reg", NULL);
+			reg = get_property(gpiop, "reg", NULL);
 			if (reg)
 				gaddr = of_translate_address(gpiop, reg);
 			if (gaddr != OF_BAD_ADDR)
@@ -486,9 +486,9 @@
 		pmu_batteries[1].flags |= PMU_BATT_TYPE_SMART;
 	} else {
 		struct device_node* prim = find_devices("power-mgt");
-		u32 *prim_info = NULL;
+		const u32 *prim_info = NULL;
 		if (prim)
-			prim_info = (u32 *)get_property(prim, "prim-info", NULL);
+			prim_info = get_property(prim, "prim-info", NULL);
 		if (prim_info) {
 			/* Other stuffs here yet unknown */
 			pmu_battery_count = (prim_info[6] >> 16) & 0xff;
diff --git a/drivers/macintosh/windfarm_pm81.c b/drivers/macintosh/windfarm_pm81.c
index f1df6ef..2ff546e 100644
--- a/drivers/macintosh/windfarm_pm81.c
+++ b/drivers/macintosh/windfarm_pm81.c
@@ -396,7 +396,7 @@
 static void wf_smu_create_cpu_fans(void)
 {
 	struct wf_cpu_pid_param pid_param;
-	struct smu_sdbp_header *hdr;
+	const struct smu_sdbp_header *hdr;
 	struct smu_sdbp_cpupiddata *piddata;
 	struct smu_sdbp_fvt *fvt;
 	s32 tmax, tdelta, maxpow, powadj;
@@ -702,7 +702,7 @@
 
 static int wf_init_pm(void)
 {
-	struct smu_sdbp_header *hdr;
+	const struct smu_sdbp_header *hdr;
 
 	hdr = smu_get_sdb_partition(SMU_SDB_SENSORTREE_ID, NULL);
 	if (hdr != 0) {
diff --git a/drivers/macintosh/windfarm_pm91.c b/drivers/macintosh/windfarm_pm91.c
index 0d6372e..59e9ffe 100644
--- a/drivers/macintosh/windfarm_pm91.c
+++ b/drivers/macintosh/windfarm_pm91.c
@@ -144,7 +144,7 @@
 static void wf_smu_create_cpu_fans(void)
 {
 	struct wf_cpu_pid_param pid_param;
-	struct smu_sdbp_header *hdr;
+	const struct smu_sdbp_header *hdr;
 	struct smu_sdbp_cpupiddata *piddata;
 	struct smu_sdbp_fvt *fvt;
 	s32 tmax, tdelta, maxpow, powadj;
diff --git a/drivers/macintosh/windfarm_smu_controls.c b/drivers/macintosh/windfarm_smu_controls.c
index a9e88ed..bff1f37 100644
--- a/drivers/macintosh/windfarm_smu_controls.c
+++ b/drivers/macintosh/windfarm_smu_controls.c
@@ -159,14 +159,15 @@
 					      int pwm_fan)
 {
 	struct smu_fan_control *fct;
-	s32 *v; u32 *reg;
-	char *l;
+	const s32 *v;
+	const u32 *reg;
+	const char *l;
 
 	fct = kmalloc(sizeof(struct smu_fan_control), GFP_KERNEL);
 	if (fct == NULL)
 		return NULL;
 	fct->ctrl.ops = &smu_fan_ops;
-	l = (char *)get_property(node, "location", NULL);
+	l = get_property(node, "location", NULL);
 	if (l == NULL)
 		goto fail;
 
@@ -223,17 +224,17 @@
 		goto fail;
 
 	/* Get min & max values*/
-	v = (s32 *)get_property(node, "min-value", NULL);
+	v = get_property(node, "min-value", NULL);
 	if (v == NULL)
 		goto fail;
 	fct->min = *v;
-	v = (s32 *)get_property(node, "max-value", NULL);
+	v = get_property(node, "max-value", NULL);
 	if (v == NULL)
 		goto fail;
 	fct->max = *v;
 
 	/* Get "reg" value */
-	reg = (u32 *)get_property(node, "reg", NULL);
+	reg = get_property(node, "reg", NULL);
 	if (reg == NULL)
 		goto fail;
 	fct->reg = *reg;
diff --git a/drivers/macintosh/windfarm_smu_sat.c b/drivers/macintosh/windfarm_smu_sat.c
index e295a07..aceb61d 100644
--- a/drivers/macintosh/windfarm_smu_sat.c
+++ b/drivers/macintosh/windfarm_smu_sat.c
@@ -233,15 +233,15 @@
 {
 	struct wf_sat *sat;
 	struct wf_sat_sensor *sens;
-	u32 *reg;
-	char *loc, *type;
+	const u32 *reg;
+	const char *loc, *type;
 	u8 addr, chip, core;
 	struct device_node *child;
 	int shift, cpu, index;
 	char *name;
 	int vsens[2], isens[2];
 
-	reg = (u32 *) get_property(dev, "reg", NULL);
+	reg = get_property(dev, "reg", NULL);
 	if (reg == NULL)
 		return;
 	addr = *reg;
@@ -268,7 +268,7 @@
 	isens[0] = isens[1] = -1;
 	child = NULL;
 	while ((child = of_get_next_child(dev, child)) != NULL) {
-		reg = (u32 *) get_property(child, "reg", NULL);
+		reg = get_property(child, "reg", NULL);
 		type = get_property(child, "device_type", NULL);
 		loc = get_property(child, "location", NULL);
 		if (reg == NULL || loc == NULL)
diff --git a/drivers/macintosh/windfarm_smu_sensors.c b/drivers/macintosh/windfarm_smu_sensors.c
index bed25dc..defe992 100644
--- a/drivers/macintosh/windfarm_smu_sensors.c
+++ b/drivers/macintosh/windfarm_smu_sensors.c
@@ -198,14 +198,14 @@
 static struct smu_ad_sensor *smu_ads_create(struct device_node *node)
 {
 	struct smu_ad_sensor *ads;
-	char *c, *l;
-	u32 *v;
+	const char *c, *l;
+	const u32 *v;
 
 	ads = kmalloc(sizeof(struct smu_ad_sensor), GFP_KERNEL);
 	if (ads == NULL)
 		return NULL;
-	c = (char *)get_property(node, "device_type", NULL);
-	l = (char *)get_property(node, "location", NULL);
+	c = get_property(node, "device_type", NULL);
+	l = get_property(node, "location", NULL);
 	if (c == NULL || l == NULL)
 		goto fail;
 
@@ -255,7 +255,7 @@
 	} else
 		goto fail;
 
-	v = (u32 *)get_property(node, "reg", NULL);
+	v = get_property(node, "reg", NULL);
 	if (v == NULL)
 		goto fail;
 	ads->reg = *v;
@@ -382,7 +382,7 @@
 
 static void smu_fetch_param_partitions(void)
 {
-	struct smu_sdbp_header *hdr;
+	const struct smu_sdbp_header *hdr;
 
 	/* Get CPU voltage/current/power calibration data */
 	hdr = smu_get_sdb_partition(SMU_SDB_CPUVCP_ID, NULL);
diff --git a/drivers/serial/pmac_zilog.c b/drivers/serial/pmac_zilog.c
index bfd2a22..a3b99ca 100644
--- a/drivers/serial/pmac_zilog.c
+++ b/drivers/serial/pmac_zilog.c
@@ -1400,8 +1400,8 @@
 static int __init pmz_init_port(struct uart_pmac_port *uap)
 {
 	struct device_node *np = uap->node;
-	char *conn;
-	struct slot_names_prop {
+	const char *conn;
+	const struct slot_names_prop {
 		int	count;
 		char	name[1];
 	} *slots;
@@ -1458,7 +1458,7 @@
 		uap->flags |= PMACZILOG_FLAG_IS_IRDA;
 	uap->port_type = PMAC_SCC_ASYNC;
 	/* 1999 Powerbook G3 has slot-names property instead */
-	slots = (struct slot_names_prop *)get_property(np, "slot-names", &len);
+	slots = get_property(np, "slot-names", &len);
 	if (slots && slots->count > 0) {
 		if (strcmp(slots->name, "IrDA") == 0)
 			uap->flags |= PMACZILOG_FLAG_IS_IRDA;
@@ -1470,7 +1470,8 @@
 	if (ZS_IS_INTMODEM(uap)) {
 		struct device_node* i2c_modem = find_devices("i2c-modem");
 		if (i2c_modem) {
-			char* mid = get_property(i2c_modem, "modem-id", NULL);
+			const char* mid =
+				get_property(i2c_modem, "modem-id", NULL);
 			if (mid) switch(*mid) {
 			case 0x04 :
 			case 0x05 :