diff --git a/arch/arm/mach-at91/include/mach/atmel_pio4.h b/arch/arm/mach-at91/include/mach/atmel_pio4.h
index 81e0e9f..b7d6f5a 100644
--- a/arch/arm/mach-at91/include/mach/atmel_pio4.h
+++ b/arch/arm/mach-at91/include/mach/atmel_pio4.h
@@ -47,6 +47,10 @@ struct atmel_pio4_port {
 #define ATMEL_PIO_IFSCEN_MASK		BIT(13)
 #define ATMEL_PIO_OPD_MASK		BIT(14)
 #define ATMEL_PIO_SCHMITT_MASK		BIT(15)
+#define ATMEL_PIO_DRVSTR_MASK		GENMASK(17, 16)
+#define ATMEL_PIO_DRVSTR_LO		(1 << 16)
+#define ATMEL_PIO_DRVSTR_ME		(2 << 16)
+#define ATMEL_PIO_DRVSTR_HI		(3 << 16)
 #define ATMEL_PIO_CFGR_EVTSEL_MASK	GENMASK(26, 24)
 #define ATMEL_PIO_CFGR_EVTSEL_FALLING	(0 << 24)
 #define ATMEL_PIO_CFGR_EVTSEL_RISING	(1 << 24)