diff --git a/include/grub/cs5536.h b/include/grub/cs5536.h
index c2323fe9b..218e17d1a 100644
--- a/include/grub/cs5536.h
+++ b/include/grub/cs5536.h
@@ -39,6 +39,11 @@
 #define GRUB_CS5536_PM_REGS_SIZE 128
 #define GRUB_CS5536_ACPI_REGS_SIZE 32
 
+#define GRUB_CS5536_USB_OPTION_REGS_SIZE 0x1c
+#define GRUB_CS5536_USB_OPTION_REG_UOCMUX  1
+#define GRUB_CS5536_USB_OPTION_REG_UOCMUX_PMUX_MASK 0x03
+#define GRUB_CS5536_USB_OPTION_REG_UOCMUX_PMUX_HC   0x02
+
 #define GRUB_CS5536_DESTINATION_GLIU     0
 #define GRUB_CS5536_DESTINATION_GLPCI_SB 1
 #define GRUB_CS5536_DESTINATION_USB      2
@@ -78,9 +83,11 @@
 #define GRUB_CS5536_MSR_USB_EHCI_BASE 0x40000009
 #define GRUB_CS5536_MSR_USB_CONTROLLER_BASE 0x4000000a
 #define GRUB_CS5536_MSR_USB_OPTION_CONTROLLER_BASE 0x4000000b
-#define GRUB_CS5536_MSR_USB_BASE_ADDR_MASK     0xffffff00
-#define GRUB_CS5536_MSR_USB_BASE_BUS_MASTER    0x400000000ULL
-#define GRUB_CS5536_MSR_USB_BASE_MEMORY_ENABLE 0x200000000ULL
+#define GRUB_CS5536_MSR_USB_BASE_ADDR_MASK     0x00ffffff00ULL
+#define GRUB_CS5536_MSR_USB_BASE_BUS_MASTER    0x0400000000ULL
+#define GRUB_CS5536_MSR_USB_BASE_MEMORY_ENABLE 0x0200000000ULL
+#define GRUB_CS5536_MSR_USB_BASE_PME_ENABLED       0x0800000000ULL
+#define GRUB_CS5536_MSR_USB_BASE_PME_STATUS        0x1000000000ULL
 #define GRUB_CS5536_MSR_USB_EHCI_BASE_FLDJ_SHIFT 40
 
 #define GRUB_CS5536_MSR_IDE_IO_BAR 0x60000008
diff --git a/kern/mips/yeeloong/init.c b/kern/mips/yeeloong/init.c
index cf241ea96..5c3340f39 100644
--- a/kern/mips/yeeloong/init.c
+++ b/kern/mips/yeeloong/init.c
@@ -239,6 +239,19 @@ grub_machine_init (void)
       set_p2d (dev, 5, GRUB_CS5536_DESTINATION_USB, 0x05024000);
       set_p2d (dev, 6, GRUB_CS5536_DESTINATION_USB, 0x05023000);
 
+      {
+	volatile grub_uint32_t *oc;
+	oc = grub_pci_device_map_range (dev, 0x05022000,
+					GRUB_CS5536_USB_OPTION_REGS_SIZE);
+
+	oc[GRUB_CS5536_USB_OPTION_REG_UOCMUX] =
+	  (oc[GRUB_CS5536_USB_OPTION_REG_UOCMUX]
+	   & ~GRUB_CS5536_USB_OPTION_REG_UOCMUX_PMUX_MASK)
+	  | GRUB_CS5536_USB_OPTION_REG_UOCMUX_PMUX_HC;
+	grub_pci_device_unmap_range (dev, oc, GRUB_CS5536_USB_OPTION_REGS_SIZE);
+      }
+
+
       /* Setup IDE controller.  */
       grub_cs5536_write_msr (dev, GRUB_CS5536_MSR_IDE_IO_BAR,
 			     GRUB_CS5536_LBAR_IDE