soc/amd/genoa: Enable uart

Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Signed-off-by: Varshit Pandya <pandyavarshit@gmail.com>
Change-Id: I1529657f30b6e228c2e3cd7e0438255522381367
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76507
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

5 files changed, 59 insertions, 0 deletions

diff --git a/src/soc/amd/genoa/Kconfig b/src/soc/amd/genoa/Kconfig
index b4caa5685f..af4056a90b 100644
--- a/src/soc/amd/genoa/Kconfig
+++ b/src/soc/amd/genoa/Kconfig
@@ -19,6 +19,7 @@ config SOC_SPECIFIC_OPTIONS
 	select SOC_AMD_COMMON_BLOCK_PCI_MMCONF
 	select SOC_AMD_COMMON_BLOCK_SMI
 	select SOC_AMD_COMMON_BLOCK_TSC
+	select SOC_AMD_COMMON_BLOCK_UART
 	select SOC_AMD_COMMON_BLOCK_USE_ESPI
 	select X86_CUSTOM_BOOTMEDIA
 
diff --git a/src/soc/amd/genoa/Makefile.inc b/src/soc/amd/genoa/Makefile.inc
index a35146cb1d..ef8f349e8c 100644
--- a/src/soc/amd/genoa/Makefile.inc
+++ b/src/soc/amd/genoa/Makefile.inc
@@ -5,6 +5,7 @@ all-y		+= mmap_boot.c
 all-y		+= reset.c
 all-y		+= config.c
 all-y		+= gpio.c
+all-y		+= uart.c
 
 bootblock-y	+= early_fch.c
 bootblock-y	+= aoac.c
diff --git a/src/soc/amd/genoa/early_fch.c b/src/soc/amd/genoa/early_fch.c
index 8de43e22e3..e134f49e18 100644
--- a/src/soc/amd/genoa/early_fch.c
+++ b/src/soc/amd/genoa/early_fch.c
@@ -7,6 +7,7 @@
 #include <amdblocks/pmlib.h>
 #include <amdblocks/uart.h>
 #include <soc/southbridge.h>
+#include <soc/uart.h>
 
 /* Before console init */
 void fch_pre_init(void)
@@ -14,6 +15,14 @@ void fch_pre_init(void)
 	fch_enable_cf9_io();
 
 	enable_aoac_devices();
+	/*
+	 * On reset Range_0 defaults to enabled. We want to start with a clean
+	 * slate to not have things unexpectedly enabled.
+	 */
+	clear_uart_legacy_config();
+
+	if (CONFIG(AMD_SOC_CONSOLE_UART))
+		set_uart_config(CONFIG_UART_FOR_CONSOLE);
 
 	configure_espi_with_mb_hook();
 }
diff --git a/src/soc/amd/genoa/include/soc/uart.h b/src/soc/amd/genoa/include/soc/uart.h
new file mode 100644
index 0000000000..ae8f118461
--- /dev/null
+++ b/src/soc/amd/genoa/include/soc/uart.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef AMD_GENOA_UART_H
+#define AMD_GENOA_UART_H
+
+#include <types.h>
+
+void clear_uart_legacy_config(void); /* disable legacy I/O decode for FCH UART */
+
+#endif /* AMD_GENOA_UART_H */
diff --git a/src/soc/amd/genoa/uart.c b/src/soc/amd/genoa/uart.c
new file mode 100644
index 0000000000..df8c54f700
--- /dev/null
+++ b/src/soc/amd/genoa/uart.c
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <device/mmio.h>
+#include <amdblocks/gpio.h>
+#include <amdblocks/uart.h>
+#include <commonlib/helpers.h>
+#include <soc/aoac_defs.h>
+#include <soc/gpio.h>
+#include <soc/iomap.h>
+#include <soc/southbridge.h>
+#include <soc/uart.h>
+#include <types.h>
+
+static const struct soc_uart_ctrlr_info uart_info[] = {
+	[0] =	{ APU_UART0_BASE, FCH_AOAC_DEV_UART0, "FUR0", {
+			PAD_NF(GPIO_136, UART0_RXD, PULL_NONE),
+			PAD_NF(GPIO_138, UART0_TXD, PULL_NONE),
+		} },
+	[1] =	{ APU_UART1_BASE, FCH_AOAC_DEV_UART1, "FUR1", {
+			PAD_NF(GPIO_141, UART1_RXD, PULL_NONE),
+			PAD_NF(GPIO_142, UART1_TXD, PULL_NONE),
+		} },
+	[2] =	{ APU_UART2_BASE, FCH_AOAC_DEV_UART2, "FUR2", {
+			PAD_NF(GPIO_137, UART2_RXD, PULL_NONE),
+			PAD_NF(GPIO_135, UART2_TXD, PULL_NONE),
+		} },
+};
+
+const struct soc_uart_ctrlr_info *soc_get_uart_ctrlr_info(size_t *num_ctrlrs)
+{
+	*num_ctrlrs = ARRAY_SIZE(uart_info);
+	return uart_info;
+}
+
+void clear_uart_legacy_config(void)
+{
+	write16((void *)FCH_LEGACY_UART_DECODE, 0);
+}