diff --git a/arch/arm/boot/dts/rk3506.dtsi b/arch/arm/boot/dts/rk3506.dtsi
index 3fcf7ab090f6..2471e9e2e9a1 100644
--- a/arch/arm/boot/dts/rk3506.dtsi
+++ b/arch/arm/boot/dts/rk3506.dtsi
@@ -472,6 +472,7 @@
 		clock-names = "spiclk", "apb_pclk";
 		dmas = <&dmac0 0>, <&dmac0 1>;
 		dma-names = "tx", "rx";
+		num-cs = <2>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&spi0_csn0_pins &spi0_csn1_pins &spi0_clk_pins>;
 		status = "disabled";
@@ -487,6 +488,7 @@
 		clock-names = "spiclk", "apb_pclk";
 		dmas = <&dmac0 2>, <&dmac0 3>;
 		dma-names = "tx", "rx";
+		num-cs = <2>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&spi1_csn0_pins &spi1_csn1_pins &spi1_clk_pins>;
 		status = "disabled";