soc/amd/cezanne: add console UART support

Change-Id: I1a01cc745c7049dc672bca12df5c6b764ac9b907
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49376
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/amd/cezanne/Kconfig

@@ -25,6 +25,7 @@ config SOC_SPECIFIC_OPTIONS
 	select SOC_AMD_COMMON_BLOCK_SMBUS
 	select SOC_AMD_COMMON_BLOCK_SMI
 	select SOC_AMD_COMMON_BLOCK_TSC_FAM17H_19H
+	select SOC_AMD_COMMON_BLOCK_UART
 
 config CHIPSET_DEVICETREE
 	string
@@ -106,4 +107,10 @@ config MMCONF_BUS_NUMBER
 	int
 	default 64
 
+config CONSOLE_UART_BASE_ADDRESS
+	depends on CONSOLE_SERIAL && AMD_SOC_CONSOLE_UART
+	hex
+	default 0xfedc9000 if UART_FOR_CONSOLE = 0
+	default 0xfedca000 if UART_FOR_CONSOLE = 1
+
 endif # SOC_AMD_CEZANNE

src/soc/amd/cezanne/Makefile.inc

@@ -11,17 +11,21 @@ bootblock-y	+= bootblock.c
 bootblock-y	+= early_fch.c
 bootblock-y	+= gpio.c
 bootblock-y     += reset.c
+bootblock-y	+= uart.c
 
 verstage_x86-y	+= gpio.c
 verstage_x86-y  += reset.c
+verstage_x86-y	+= uart.c
 
 romstage-y	+= gpio.c
 romstage-y      += reset.c
 romstage-y	+= romstage.c
+romstage-y	+= uart.c
 
 ramstage-y	+= chip.c
 ramstage-y	+= gpio.c
 ramstage-y      += reset.c
+ramstage-y	+= uart.c
 
 CPPFLAGS_common += -I$(src)/soc/amd/cezanne/include
 

src/soc/amd/cezanne/early_fch.c

@@ -4,6 +4,7 @@
 #include <amdblocks/smbus.h>
 #include <console/console.h>
 #include <soc/southbridge.h>
+#include <soc/uart.h>
 
 /* Before console init */
 void fch_pre_init(void)
@@ -12,6 +13,15 @@ void fch_pre_init(void)
 	fch_smbus_init();
 	fch_enable_cf9_io();
 	fch_enable_legacy_io();
+
+	/*
+	 * 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);
 }
 
 /* After console init */

src/soc/amd/cezanne/include/soc/iomap.h

@@ -3,6 +3,14 @@
 #ifndef AMD_CEZANNE_IOMAP_H
 #define AMD_CEZANNE_IOMAP_H
 
+/* FCH AL2AHB Registers */
+#define ALINK_AHB_ADDRESS		0xfedc0000
+
+#define APU_DMAC0_BASE			0xfedc7000
+#define APU_DMAC1_BASE			0xfedc8000
+#define APU_UART0_BASE			0xfedc9000
+#define APU_UART1_BASE			0xfedca000
+
 /* MMIO Ranges */
 #define FLASH_BASE_ADDR			((0xffffffff - CONFIG_ROM_SIZE) + 1)
 

src/soc/amd/cezanne/include/soc/southbridge.h

@@ -10,6 +10,8 @@
 #define   TOGGLE_ALL_PWR_GOOD		(1 << 1)
 #define PM_ACPI_SMI_CMD			0x6a
 
+#define FCH_LEGACY_UART_DECODE		(ALINK_AHB_ADDRESS + 0x20) /* 0xfedc0020 */
+
 /* IO 0xf0 NCP Error */
 #define   NCP_WARM_BOOT			(1 << 7) /* Write-once */
 

src/soc/amd/cezanne/include/soc/uart.h

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef AMD_PICASSO_UART_H
+#define AMD_PICASSO_UART_H
+
+#include <types.h>
+
+void set_uart_config(unsigned int idx); /* configure hardware of FCH UART selected by idx */
+void clear_uart_legacy_config(void); /* disable legacy I/O decode for FCH UART */
+
+#endif /* AMD_PICASSO_UART_H */

src/soc/amd/cezanne/uart.c

@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <amdblocks/gpio_banks.h>
+#include <amdblocks/uart.h>
+#include <commonlib/helpers.h>
+#include <device/mmio.h>
+#include <soc/gpio.h>
+#include <soc/southbridge.h>
+#include <soc/uart.h>
+#include <types.h>
+
+static const struct _uart_info {
+	uintptr_t base;
+	struct soc_amd_gpio mux[2];
+} uart_info[] = {
+	[0] = { APU_UART0_BASE, {
+			PAD_NF(GPIO_143, UART0_TXD, PULL_NONE),
+			PAD_NF(GPIO_141, UART0_RXD, PULL_NONE),
+	} },
+	[1] = { APU_UART1_BASE, {
+			PAD_NF(GPIO_140, UART1_TXD, PULL_NONE),
+			PAD_NF(GPIO_142, UART1_RXD, PULL_NONE),
+	} },
+};
+
+uintptr_t get_uart_base(unsigned int idx)
+{
+	if (idx >= ARRAY_SIZE(uart_info))
+		return 0;
+
+	return uart_info[idx].base;
+}
+
+void clear_uart_legacy_config(void)
+{
+	write16((void *)FCH_LEGACY_UART_DECODE, 0);
+}
+
+void set_uart_config(unsigned int idx)
+{
+	if (idx >= ARRAY_SIZE(uart_info))
+		return;
+
+	program_gpios(uart_info[idx].mux, 2);
+}