diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 1575a9b..71ef9cd 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -338,7 +338,8 @@
 {
 	struct acpi_button *button;
 	struct input_dev *input;
-	char *hid, *name, *class;
+	const char *hid = acpi_device_hid(device);
+	char *name, *class;
 	int error;
 
 	button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
@@ -353,7 +354,6 @@
 		goto err_free_button;
 	}
 
-	hid = acpi_device_hid(device);
 	name = acpi_device_name(device);
 	class = acpi_device_class(device);
 
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 81aec8d..6155eeb 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -26,8 +26,7 @@
 
 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
 
-/* Should be const */
-static char* dummy_hid = "device";
+static const char *dummy_hid = "device";
 
 static LIST_HEAD(acpi_device_list);
 static LIST_HEAD(acpi_bus_id_list);
@@ -1021,7 +1020,7 @@
 	return acpi_get_handle(device->handle, "_DCK", &tmp);
 }
 
-char *acpi_device_hid(struct acpi_device *device)
+const char *acpi_device_hid(struct acpi_device *device)
 {
 	struct acpi_hardware_id *hid;
 
diff --git a/drivers/pnp/base.h b/drivers/pnp/base.h
index 0bab84e..19bc736 100644
--- a/drivers/pnp/base.h
+++ b/drivers/pnp/base.h
@@ -12,11 +12,12 @@
 
 #define PNP_EISA_ID_MASK 0x7fffffff
 void pnp_eisa_id_to_string(u32 id, char *str);
-struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *, int id, char *pnpid);
+struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *, int id,
+			      const char *pnpid);
 struct pnp_card *pnp_alloc_card(struct pnp_protocol *, int id, char *pnpid);
 
 int pnp_add_device(struct pnp_dev *dev);
-struct pnp_id *pnp_add_id(struct pnp_dev *dev, char *id);
+struct pnp_id *pnp_add_id(struct pnp_dev *dev, const char *id);
 
 int pnp_add_card(struct pnp_card *card);
 void pnp_remove_card(struct pnp_card *card);
diff --git a/drivers/pnp/core.c b/drivers/pnp/core.c
index 88b3cde..c79ee1d 100644
--- a/drivers/pnp/core.c
+++ b/drivers/pnp/core.c
@@ -124,7 +124,8 @@
 	kfree(dev);
 }
 
-struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id, char *pnpid)
+struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id,
+			      const char *pnpid)
 {
 	struct pnp_dev *dev;
 	struct pnp_id *dev_id;
diff --git a/drivers/pnp/driver.c b/drivers/pnp/driver.c
index cd11b11..d1dbb9d 100644
--- a/drivers/pnp/driver.c
+++ b/drivers/pnp/driver.c
@@ -236,7 +236,7 @@
  * @dev: pointer to the desired device
  * @id: pointer to an EISA id string
  */
-struct pnp_id *pnp_add_id(struct pnp_dev *dev, char *id)
+struct pnp_id *pnp_add_id(struct pnp_dev *dev, const char *id)
 {
 	struct pnp_id *dev_id, *ptr;
 
diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
index dc4e32e..4aafcf8 100644
--- a/drivers/pnp/pnpacpi/core.c
+++ b/drivers/pnp/pnpacpi/core.c
@@ -59,7 +59,7 @@
 #define TEST_ALPHA(c) \
 	if (!('@' <= (c) || (c) <= 'Z')) \
 		return 0
-static int __init ispnpidacpi(char *id)
+static int __init ispnpidacpi(const char *id)
 {
 	TEST_ALPHA(id[0]);
 	TEST_ALPHA(id[1]);
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 4de84ce..a47bb90 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -184,7 +184,7 @@
 
 #define acpi_device_bid(d)	((d)->pnp.bus_id)
 #define acpi_device_adr(d)	((d)->pnp.bus_address)
-char *acpi_device_hid(struct acpi_device *device);
+const char *acpi_device_hid(struct acpi_device *device);
 #define acpi_device_name(d)	((d)->pnp.device_name)
 #define acpi_device_class(d)	((d)->pnp.device_class)