diff --git a/Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml b/Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml
index 273f2d95a04373892e774f56a1bd9d03abae7b63..ea9c233052f3382b84da3d1a07d4a7022d4ddea4 100644
--- a/Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml
+++ b/Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml
@@ -17,13 +17,6 @@ description: |
   child nodes, each representing a serial sub-node device. The mode setting
   selects which particular function will be used.
 
-  Refer to next bindings documentation for information on protocol subnodes that
-  can exist under USI node:
-
-  [1] Documentation/devicetree/bindings/serial/samsung_uart.yaml
-  [2] Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
-  [3] Documentation/devicetree/bindings/spi/spi-samsung.txt
-
 properties:
   $nodename:
     pattern: "^usi@[0-9a-f]+$"
@@ -71,10 +64,17 @@ properties:
       This property is optional.
 
 patternProperties:
-  # All other properties should be child nodes
-  "^(serial|spi|i2c)@[0-9a-f]+$":
+  "^i2c@[0-9a-f]+$":
+    $ref: /schemas/i2c/i2c-exynos5.yaml
+    description: Child node describing underlying I2C
+
+  "^serial@[0-9a-f]+$":
+    $ref: /schemas/serial/samsung_uart.yaml
+    description: Child node describing underlying UART/serial
+
+  "^spi@[0-9a-f]+$":
     type: object
-    description: Child node describing underlying USI serial protocol
+    description: Child node describing underlying SPI
 
 required:
   - compatible
diff --git a/arch/arm/mach-exynos/firmware.c b/arch/arm/mach-exynos/firmware.c
index 2eaf2dbb8e815bf2809bf48deec0ff9779b79e6e..2da5b60b59e29a82d291ccb8c2a517f8c8055fab 100644
--- a/arch/arm/mach-exynos/firmware.c
+++ b/arch/arm/mach-exynos/firmware.c
@@ -60,8 +60,10 @@ static int exynos_cpu_boot(int cpu)
 	/*
 	 * Exynos3250 doesn't need to send smc command for secondary CPU boot
 	 * because Exynos3250 removes WFE in secure mode.
+	 *
+	 * On Exynos5 devices the call is ignored by trustzone firmware.
 	 */
-	if (soc_is_exynos3250())
+	if (!soc_is_exynos4210() && !soc_is_exynos4412())
 		return 0;
 
 	/*