diff --git a/arch/mips/au1000/pb1100/board_setup.c b/arch/mips/au1000/pb1100/board_setup.c
index 2d1533f116c0c020f57a4de59c952b6167f3545c..6bc1f8e1b608175b431f6927d47aa42558d8f1cc 100644
--- a/arch/mips/au1000/pb1100/board_setup.c
+++ b/arch/mips/au1000/pb1100/board_setup.c
@@ -47,8 +47,7 @@ void board_reset (void)
 
 void __init board_setup(void)
 {
-	u32 pin_func;
-	u32 sys_freqctrl, sys_clksrc;
+	volatile void __iomem * base = (volatile void __iomem *) 0xac000000UL;
 
 	// set AUX clock to 12MHz * 8 = 96 MHz
 	au_writel(8, SYS_AUXPLL);
@@ -56,58 +55,62 @@ void __init board_setup(void)
 	udelay(100);
 
 #ifdef CONFIG_USB_OHCI
-	// configure pins GPIO[14:9] as GPIO
-	pin_func = au_readl(SYS_PINFUNC) & (u32)(~0x80);
-
-	/* zero and disable FREQ2 */
-	sys_freqctrl = au_readl(SYS_FREQCTRL0);
-	sys_freqctrl &= ~0xFFF00000;
-	au_writel(sys_freqctrl, SYS_FREQCTRL0);
-
-	/* zero and disable USBH/USBD/IrDA clock */
-	sys_clksrc = au_readl(SYS_CLKSRC);
-	sys_clksrc &= ~0x0000001F;
-	au_writel(sys_clksrc, SYS_CLKSRC);
-
-	sys_freqctrl = au_readl(SYS_FREQCTRL0);
-	sys_freqctrl &= ~0xFFF00000;
-
-	sys_clksrc = au_readl(SYS_CLKSRC);
-	sys_clksrc &= ~0x0000001F;
-
-	// FREQ2 = aux/2 = 48 MHz
-	sys_freqctrl |= ((0<<22) | (1<<21) | (1<<20));
-	au_writel(sys_freqctrl, SYS_FREQCTRL0);
-
-	/*
-	 * Route 48MHz FREQ2 into USBH/USBD/IrDA
-	 */
-	sys_clksrc |= ((4<<2) | (0<<1) | 0 );
-	au_writel(sys_clksrc, SYS_CLKSRC);
-
-	/* setup the static bus controller */
-	au_writel(0x00000002, MEM_STCFG3);  /* type = PCMCIA */
-	au_writel(0x280E3D07, MEM_STTIME3); /* 250ns cycle time */
-	au_writel(0x10000000, MEM_STADDR3); /* any PCMCIA select */
-
-	// get USB Functionality pin state (device vs host drive pins)
-	pin_func = au_readl(SYS_PINFUNC) & (u32)(~0x8000);
-	// 2nd USB port is USB host
-	pin_func |= 0x8000;
-	au_writel(pin_func, SYS_PINFUNC);
+	{
+		u32 pin_func, sys_freqctrl, sys_clksrc;
+
+		// configure pins GPIO[14:9] as GPIO
+		pin_func = au_readl(SYS_PINFUNC) & (u32)(~0x80);
+
+		/* zero and disable FREQ2 */
+		sys_freqctrl = au_readl(SYS_FREQCTRL0);
+		sys_freqctrl &= ~0xFFF00000;
+		au_writel(sys_freqctrl, SYS_FREQCTRL0);
+
+		/* zero and disable USBH/USBD/IrDA clock */
+		sys_clksrc = au_readl(SYS_CLKSRC);
+		sys_clksrc &= ~0x0000001F;
+		au_writel(sys_clksrc, SYS_CLKSRC);
+
+		sys_freqctrl = au_readl(SYS_FREQCTRL0);
+		sys_freqctrl &= ~0xFFF00000;
+
+		sys_clksrc = au_readl(SYS_CLKSRC);
+		sys_clksrc &= ~0x0000001F;
+
+		// FREQ2 = aux/2 = 48 MHz
+		sys_freqctrl |= ((0<<22) | (1<<21) | (1<<20));
+		au_writel(sys_freqctrl, SYS_FREQCTRL0);
+
+		/*
+		 * Route 48MHz FREQ2 into USBH/USBD/IrDA
+		 */
+		sys_clksrc |= ((4<<2) | (0<<1) | 0 );
+		au_writel(sys_clksrc, SYS_CLKSRC);
+
+		/* setup the static bus controller */
+		au_writel(0x00000002, MEM_STCFG3);  /* type = PCMCIA */
+		au_writel(0x280E3D07, MEM_STTIME3); /* 250ns cycle time */
+		au_writel(0x10000000, MEM_STADDR3); /* any PCMCIA select */
+
+		// get USB Functionality pin state (device vs host drive pins)
+		pin_func = au_readl(SYS_PINFUNC) & (u32)(~0x8000);
+		// 2nd USB port is USB host
+		pin_func |= 0x8000;
+		au_writel(pin_func, SYS_PINFUNC);
+	}
 #endif // defined (CONFIG_USB_OHCI)
 
 	/* Enable sys bus clock divider when IDLE state or no bus activity. */
 	au_writel(au_readl(SYS_POWERCTRL) | (0x3 << 5), SYS_POWERCTRL);
 
 	// Enable the RTC if not already enabled
-	if (!(readb(0xac000028) & 0x20)) {
-		writeb(readb(0xac000028) | 0x20, 0xac000028);
+	if (!(readb(base + 0x28) & 0x20)) {
+		writeb(readb(base + 0x28) | 0x20, base + 0x28);
 		au_sync();
 	}
 	// Put the clock in BCD mode
-	if (readb(0xac00002C) & 0x4) { /* reg B */
-		writeb(readb(0xac00002c) & ~0x4, 0xac00002c);
+	if (readb(base + 0x2C) & 0x4) { /* reg B */
+		writeb(readb(base + 0x2c) & ~0x4, base + 0x2c);
 		au_sync();
 	}
 }