[PATCH v1] MdeModulePkg: BaseSerialPortLib16550: Add Mmio32 support

[PATCH v1] MdeModulePkg: BaseSerialPortLib16550: Add Mmio32 support

[Wu, Hao A]

From: "Tien Hock, Loh" <tien.hock.loh@intel.com>

Some busses doesn't allow 8 bit MMIO read/write, this adds support for
32 bits read/write

Signed-off-by: "Tien Hock, Loh" <tien.hock.loh@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
---
 MdeModulePkg/MdeModulePkg.dec                                          |  6 ++++++
 MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf |  1 +
 MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c   | 10 ++++++++--
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index be84916cc0..4e53625767 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -1170,6 +1170,12 @@
   # @Prompt Serial port registers use MMIO.
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseMmio|FALSE|BOOLEAN|0x00020000
 
+  ## Indicates the 16550 serial port registers are in MMIO 32 bit space, or in I/O space. Default is I/O space.<BR><BR>
+  #   TRUE  - 16550 serial port registers are in MMIO 32 bit space.<BR>
+  #   FALSE - 16550 serial port registers are in I/O space.<BR>
+  # @Prompt Serial port registers use MMIO.
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseMmio32|FALSE|BOOLEAN|0x00020007
+
   ## Indicates if the 16550 serial port hardware flow control will be enabled. Default is FALSE.<BR><BR>
   #   TRUE  - 16550 serial port hardware flow control will be enabled.<BR>
   #   FALSE - 16550 serial port hardware flow control will be disabled.<BR>
diff --git a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
index b60779cf57..575728af3a 100644
--- a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
+++ b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
@@ -29,6 +29,7 @@
   BaseSerialPortLib16550.c
 
 [Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseMmio32               ## CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseMmio                 ## CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseHardwareFlowControl  ## CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialDetectCable             ## SOMETIMES_CONSUMES
diff --git a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
index 34df34d9c6..b242b23ec8 100644
--- a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
+++ b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
@@ -76,7 +76,10 @@ SerialPortReadRegister (
   UINTN  Offset
   )
 {
-  if (PcdGetBool (PcdSerialUseMmio)) {
+  if (PcdGetBool (PcdSerialUseMmio32)) {
+    return (UINT8) MmioRead32 (Base + Offset * PcdGet32 (PcdSerialRegisterStride));
+  }
+  else if (PcdGetBool (PcdSerialUseMmio)) {
     return MmioRead8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride));
   } else {
     return IoRead8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride));
@@ -103,7 +106,10 @@ SerialPortWriteRegister (
   UINT8  Value
   )
 {
-  if (PcdGetBool (PcdSerialUseMmio)) {
+  if (PcdGetBool (PcdSerialUseMmio32)) {
+    return MmioWrite32 (Base + Offset * PcdGet32 (PcdSerialRegisterStride), (UINT8)Value);
+  }
+  else if (PcdGetBool (PcdSerialUseMmio)) {
     return MmioWrite8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride), Value);
   } else {
     return IoWrite8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride), Value);
-- 
2.12.0.windows.1