diff --git a/arch/arm/boot/dts/microchip/sam9x60.dtsi b/arch/arm/boot/dts/microchip/sam9x60.dtsi
index 04a6d716ecaf..0ba424bba7cc 100644
--- a/arch/arm/boot/dts/microchip/sam9x60.dtsi
+++ b/arch/arm/boot/dts/microchip/sam9x60.dtsi
@@ -174,6 +174,7 @@ flx4: flexcom@f0000000 {
 				uart4: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <13 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -376,6 +377,7 @@ flx11: flexcom@f0020000 {
 				uart11: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <32 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -427,6 +429,7 @@ flx12: flexcom@f0024000 {
 				uart12: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <33 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -586,6 +589,7 @@ flx6: flexcom@f8010000 {
 				uart6: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <9 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -637,6 +641,7 @@ flx7: flexcom@f8014000 {
 				uart7: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <10 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -688,6 +693,7 @@ flx8: flexcom@f8018000 {
 				uart8: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <11 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -739,6 +745,7 @@ flx0: flexcom@f801c000 {
 				uart0: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <5 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -809,6 +816,7 @@ flx1: flexcom@f8020000 {
 				uart1: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <6 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -879,6 +887,7 @@ flx2: flexcom@f8024000 {
 				uart2: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <7 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -949,6 +958,7 @@ flx3: flexcom@f8028000 {
 				uart3: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <8 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -1074,6 +1084,7 @@ flx9: flexcom@f8040000 {
 				uart9: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <15 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
@@ -1125,6 +1136,7 @@ flx10: flexcom@f8044000 {
 				uart10: serial@200 {
 					compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
 					reg = <0x200 0x200>;
+					atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 					interrupts = <16 IRQ_TYPE_LEVEL_HIGH 7>;
 					dmas = <&dma0
 						(AT91_XDMAC_DT_MEM_IF(0) |
