diff --git a/include/miiphy.h b/include/miiphy.h
index 5362125..2f7d915 100644
--- a/include/miiphy.h
+++ b/include/miiphy.h
@@ -36,30 +36,30 @@
 
 #include <net.h>
 
-int miiphy_read (char *devname, unsigned char addr, unsigned char reg,
+int miiphy_read (const char *devname, unsigned char addr, unsigned char reg,
 		 unsigned short *value);
-int miiphy_write (char *devname, unsigned char addr, unsigned char reg,
+int miiphy_write (const char *devname, unsigned char addr, unsigned char reg,
 		  unsigned short value);
-int miiphy_info (char *devname, unsigned char addr, unsigned int *oui,
+int miiphy_info (const char *devname, unsigned char addr, unsigned int *oui,
 		 unsigned char *model, unsigned char *rev);
-int miiphy_reset (char *devname, unsigned char addr);
-int miiphy_speed (char *devname, unsigned char addr);
-int miiphy_duplex (char *devname, unsigned char addr);
-int miiphy_is_1000base_x (char *devname, unsigned char addr);
+int miiphy_reset (const char *devname, unsigned char addr);
+int miiphy_speed (const char *devname, unsigned char addr);
+int miiphy_duplex (const char *devname, unsigned char addr);
+int miiphy_is_1000base_x (const char *devname, unsigned char addr);
 #ifdef CONFIG_SYS_FAULT_ECHO_LINK_DOWN
-int miiphy_link (char *devname, unsigned char addr);
+int miiphy_link (const char *devname, unsigned char addr);
 #endif
 
 void miiphy_init (void);
 
-void miiphy_register (char *devname,
-		      int (*read) (char *devname, unsigned char addr,
+void miiphy_register (const char *devname,
+		      int (*read) (const char *devname, unsigned char addr,
 				   unsigned char reg, unsigned short *value),
-		      int (*write) (char *devname, unsigned char addr,
+		      int (*write) (const char *devname, unsigned char addr,
 				    unsigned char reg, unsigned short value));
 
-int miiphy_set_current_dev (char *devname);
-char *miiphy_get_current_dev (void);
+int miiphy_set_current_dev (const char *devname);
+const char *miiphy_get_current_dev (void);
 
 void miiphy_listdev (void);
 
@@ -85,9 +85,9 @@
 extern int bb_miiphy_buses_num;
 
 void bb_miiphy_init (void);
-int bb_miiphy_read (char *devname, unsigned char addr,
+int bb_miiphy_read (const char *devname, unsigned char addr,
 		    unsigned char reg, unsigned short *value);
-int bb_miiphy_write (char *devname, unsigned char addr,
+int bb_miiphy_write (const char *devname, unsigned char addr,
 		     unsigned char reg, unsigned short value);
 #endif