console: ast2400: Indicate SP has met configuration requirements

If the service processor has pre-configured the hardware to the state
required by the host firmware it can set a bit to indicate this. If the
bit is set, avoid touching the UART configuration.

Change-Id: I96d228b5d89749eb531522e4ae90396b47776c43
Signed-off-by: Andrew Jeffery <andrewrj@au1.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/62506
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Dean Sanner <dsanner@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Reviewed-by: Nicholas E. Bofferding <bofferdn@us.ibm.com>
Disable-CI: Nicholas E. Bofferding <bofferdn@us.ibm.com>
Disable-CI: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/usr/console/ast2400.C

@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2014,2016                        */
+/* Contributors Listed Below - COPYRIGHT 2014,2018                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -40,9 +40,6 @@ namespace CONSOLE
     const uint32_t VUART1_ADDRL     = VUART1_BASE + 0x28;
     const uint32_t VUART1_ADDRH     = VUART1_BASE + 0x2c;
 
-    // used to test config flags related to console output selection
-    const uint8_t CONFIG_MASK       = 0xC0;
-
     /** Overload the base class with Ast2400 specifics.
      *
      *  In initialization we need to program the SIO device on the AST2400 to
@@ -51,6 +48,21 @@ namespace CONSOLE
     class Ast2400Uart : public Uart
     {
      public:
+        enum platFlagsMask_t
+        {
+            /**
+             * @brief ISOLATE_SP flag
+             *
+             * If the ISOLATE_SP flag is set, then the service processor must
+             * configure:
+             *
+             * 1. A UART device at 0x3f8, SIRQ 4, low polarity
+             * 2. The BT device at 0xe4, SIRQ 10, low polarity
+             */
+            ISOLATE_SP      = 0x01,
+            CONSOLE_FLAGS   = 0xc0,
+        };
+
         enum consoleConfig_t
         {
             NONE            = 0x00,  // No output selected
@@ -281,7 +293,7 @@ namespace CONSOLE
 
             errlHndl_t l_err = NULL;
             size_t l_len = sizeof(uint8_t);
-            uint8_t uart_config = 0x00;
+            uint8_t plat_config = 0x00;
 
             do
             {
@@ -297,16 +309,23 @@ namespace CONSOLE
                 {
                     l_err = deviceOp( DeviceFW::READ,
                                       TARGETING::MASTER_PROCESSOR_CHIP_TARGET_SENTINEL,
-                                      &(uart_config),
+                                      &(plat_config),
                                       l_len,
                                       DEVICE_SIO_ADDRESS(SIO::SUART1, 0x2d));
                     if (l_err) { break; }
 
+                    if (plat_config & ISOLATE_SP)
+                    {
+                        printk("ast2400: UART configured by BMC\n");
+                        Uart::initialize();
+                        break;
+                    }
+
                     // determine which config has been selected
-                    consoleConfig_t config =
-                        static_cast<consoleConfig_t>(uart_config & CONFIG_MASK);
+                    consoleConfig_t uart_config =
+                        static_cast<consoleConfig_t>(plat_config & CONSOLE_FLAGS);
 
-                    switch ( config )
+                    switch ( uart_config )
                     {
                         case SELECT_SUART:
                             {