x86: baytrail: acpi: Hide internal UART per GNVS setting

If global NVS says internal UART is not enabled, hide it in the ASL
code so that OS won't see it.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Tested-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/x86/include/asm/arch-baytrail/acpi/lpc.asl b/arch/x86/include/asm/arch-baytrail/acpi/lpc.asl
index 22f0d68..fe34d32 100644 (file)
--- a/arch/x86/include/asm/arch-baytrail/acpi/lpc.asl
+++ b/arch/x86/include/asm/arch-baytrail/acpi/lpc.asl
@@ -119,17 +119,14 @@ Device (LPCB)
 
                Method(_STA, 0, Serialized)
                {
-                       /*
-                        * TODO:
-                        *
-                        * Need to hide the internal UART depending on whether
-                        * internal UART is enabled or not so that external
-                        * SuperIO UART can be exposed to system.
-                        */
-                       Store(1, UI3E)
-                       Store(1, UI4E)
-                       Store(1, C1EN)
-                       Return (STA_VISIBLE)
+                       If (LEqual(IURE, 1)) {
+                               Store(1, UI3E)
+                               Store(1, UI4E)
+                               Store(1, C1EN)
+                               Return (STA_VISIBLE)
+                       } Else {
+                               Return (STA_MISSING)
+                       }
 
                }