Please try this:
Your layout should be similar to example: 
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >
    <EditText
        android:id="@+id/edittext"
        android:layout_width="200dp"
        android:layout_height="500dp"
        android:text="some long text"
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />
</LinearLayout>
</ScrollView>
and in your java try this:
EditText edit = (EditText)findViewById(R.id.edittext);
edit.setOnTouchListener(new OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        if (v.getId() == R.id.edittext) {
            v.getParent().requestDisallowInterceptTouchEvent(true);
            switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_UP:
                v.getParent().requestDisallowInterceptTouchEvent(false);
                break;
            }
        }
        return false;
    }
});
It could be helpful.