diff --git a/include/linux/sm501-regs.h b/include/linux/sm501-regs.h
index 014e73b3..df7620d 100644
--- a/include/linux/sm501-regs.h
+++ b/include/linux/sm501-regs.h
@@ -15,6 +15,24 @@
 
 /* config 1 */
 #define SM501_SYSTEM_CONTROL 		(0x000000)
+
+#define SM501_SYSCTRL_PANEL_TRISTATE	(1<<0)
+#define SM501_SYSCTRL_MEM_TRISTATE	(1<<1)
+#define SM501_SYSCTRL_CRT_TRISTATE	(1<<2)
+
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_MASK (3<<4)
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_1	(0<<4)
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_2	(1<<4)
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_4	(2<<4)
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_8	(3<<4)
+
+#define SM501_SYSCTRL_PCI_CLOCK_RUN_EN	(1<<6)
+#define SM501_SYSCTRL_PCI_RETRY_DISABLE	(1<<7)
+#define SM501_SYSCTRL_PCI_SUBSYS_LOCK	(1<<11)
+#define SM501_SYSCTRL_PCI_BURST_READ_EN	(1<<15)
+
+/* miscellaneous control */
+
 #define SM501_MISC_CONTROL		(0x000004)
 
 #define SM501_MISC_BUS_SH		(0x0)