soc/intel/common: provide default tis_plat_irq_status() implementation

On Intel platforms utilizing the CR50 TPM the interrupts are routed
to GPIOs connected to the GPE blocks. Therefore, provide a common
implementation for tis_plat_irq_status() to reduce code duplication.
This code could be further extended to not be added based on
MAINBOARD_HAS_TPM_CR50, but that's all that's using it for now.

Change-Id: I955df0a536408b2ccd07146893337c53799e243f
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/19369
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Tested-by: build bot (Jenkins)

src/soc/intel/common/Kconfig

@@ -130,4 +130,10 @@ config SOC_INTEL_COMMON_NHLT
 	bool
 	default n
 
+config TPM_TIS_ACPI_INTERRUPT
+	int
+	help
+	  acpi_get_gpe() is used to provide interrupt status to TPM layer.
+	  This option specifies the GPE number.
+
 endif # SOC_INTEL_COMMON

src/soc/intel/common/Makefile.inc

@@ -37,6 +37,11 @@ ramstage-$(CONFIG_SOC_INTEL_COMMON_NHLT) += nhlt.c
 
 smm-$(CONFIG_SOC_INTEL_COMMON_SMI) += smihandler.c
 
+bootblock-$(CONFIG_MAINBOARD_HAS_TPM_CR50) += tpm_tis.c
+verstage-$(CONFIG_MAINBOARD_HAS_TPM_CR50) += tpm_tis.c
+romstage-$(CONFIG_MAINBOARD_HAS_TPM_CR50) += tpm_tis.c
+ramstage-$(CONFIG_MAINBOARD_HAS_TPM_CR50) += tpm_tis.c
+
 # Create and add the MRC cache to the cbfs image
 ifneq ($(CONFIG_CHROMEOS),y)
 $(obj)/mrc.cache: $(obj)/config.h

src/soc/intel/common/tpm_tis.c

@@ -0,0 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2017 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/acpi.h>
+#include <tpm.h>
+
+int tis_plat_irq_status(void)
+{
+	return acpi_get_gpe(CONFIG_TPM_TIS_ACPI_INTERRUPT);
+}