diff --git a/mlir/include/mlir/Dialect/Tosa/IR/TosaOps.td b/mlir/include/mlir/Dialect/Tosa/IR/TosaOps.td
--- a/mlir/include/mlir/Dialect/Tosa/IR/TosaOps.td
+++ b/mlir/include/mlir/Dialect/Tosa/IR/TosaOps.td
@@ -1705,14 +1705,16 @@
         float to signed 16      float   int16
         signed 8 to float       int8    float
         signed 16 to float      int16   float
+        float 32 to float 64    float32 float64
+        float 64 to float 32    float64 float32
   }];
 
   let arguments = (ins
-    Tosa_Tensor:$input
+    Tosa_Tensor_Cast:$input
   );
 
   let results = (outs
-    Tosa_Tensor:$output
+    Tosa_Tensor_Cast:$output
   );
 
   let hasFolder = 1;
diff --git a/mlir/include/mlir/Dialect/Tosa/IR/TosaTypesBase.td b/mlir/include/mlir/Dialect/Tosa/IR/TosaTypesBase.td
--- a/mlir/include/mlir/Dialect/Tosa/IR/TosaTypesBase.td
+++ b/mlir/include/mlir/Dialect/Tosa/IR/TosaTypesBase.td
@@ -95,6 +95,9 @@
 //===----------------------------------------------------------------------===//
 def Tosa_AnyNumber : AnyTypeOf<[Tosa_Int, Tosa_QuantizedInt, Tosa_Float],
                                "number">;
+// Add F64 type support for just for tosa::CastOp
+def Tosa_AnyNumber_Cast : AnyTypeOf<[Tosa_Int, Tosa_QuantizedInt, Tosa_Float, F64],
+                               "number_cast">;
 
 //===----------------------------------------------------------------------===//
 // Tensor types
@@ -105,6 +108,7 @@
 
 // Either ranked or unranked tensor of TOSA supported element types.
 def Tosa_Tensor : TensorOf<[Tosa_AnyNumber]>;
+def Tosa_Tensor_Cast : TensorOf<[Tosa_AnyNumber_Cast]>;
 // Must be ranked but no further constraints
 def Tosa_RankedTensor : RankedTensorOf<[Tosa_AnyNumber]>;
 
diff --git a/mlir/lib/Dialect/Tosa/Transforms/TosaValidation.cpp b/mlir/lib/Dialect/Tosa/Transforms/TosaValidation.cpp
--- a/mlir/lib/Dialect/Tosa/Transforms/TosaValidation.cpp
+++ b/mlir/lib/Dialect/Tosa/Transforms/TosaValidation.cpp
@@ -58,6 +58,9 @@
           getElementTypeOrSelf(operand).isa<FloatType>()) {
         return signalPassFailure();
       }
+      if (getElementTypeOrSelf(operand).isF64()) {
+        return signalPassFailure();
+      }
     }
   });
 }