feat(zynqmp): retrieval of console information from dtb

Introduces functionality to retrieve console information from the
device tree (DTB) and use it in TF-A code.

With fdt_get_stdout_node_offset() function, which reads the 'secure-chosen'
first,'chosen' and 'stdout-path' properties from the DTB, providing a
convenient and standardized way to access serial console information.

Implemented a comparison mechanism between early console information
and the data populated from the DTB. In case of a mismatch, the commit
takes care of unregistering the build-time console configuration and
registering the DTB-based console.

Reorganizes the console configuration setup in BL31 by moving it to a
dedicated function called setup_console() in the plat_console.c
file. This change improves code readability by isolating
console-related settings, making it easier to manage and extend the
console configuration in the future.

Signed-off-by: Prasad Kummari <prasad.kummari@amd.com>
Change-Id: I857042fc0fb8f070bbc11f6b47aa57a72fbe5392

plat/xilinx/common/include/plat_console.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2023, Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef PLAT_DT_UART_H
+#define PLAT_DT_UART_H
+
+#define DT_UART_DCC_COMPAT	"arm,dcc"
+
+#if defined(PLAT_zynqmp)
+#define DT_UART_COMPAT	"xlnx,zynqmp-uart"
+#else
+#define DT_UART_COMPAT	"arm,pl011"
+#endif
+
+typedef struct dt_uart_info_s {
+	char compatible[30];
+	uintptr_t base;
+	uint32_t baud_rate;
+	int32_t status;
+} dt_uart_info_t;
+
+void setup_console(void);
+
+#endif /* PLAT_DT_UART_H */

plat/xilinx/common/plat_console.c

@@ -0,0 +1,346 @@
+/*
+ * Copyright (c) 2023, Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <common/debug.h>
+#include <common/fdt_fixup.h>
+#include <common/fdt_wrappers.h>
+#include <drivers/arm/dcc.h>
+#include <drivers/arm/pl011.h>
+#include <drivers/cadence/cdns_uart.h>
+#include <drivers/console.h>
+#include <libfdt.h>
+#include <plat_console.h>
+
+#include <platform_def.h>
+#include <plat_private.h>
+
+static console_t console;
+
+#if (defined(XILINX_OF_BOARD_DTB_ADDR) && !IS_TFA_IN_OCM(BL31_BASE))
+/**
+ * get_baudrate() - Get the baudrate form DTB.
+ * @dtb: Address of the Device Tree Blob (DTB).
+ *
+ * Return: On success returns the baudrate; on failure returns an error.
+ */
+static int32_t get_baudrate(void *dtb)
+{
+	int node;
+	int32_t ret = 0;
+	const char *prop, *path;
+	char *end;
+	int32_t baud_rate = 0;
+
+	node = fdt_path_offset(dtb, "/secure-chosen");
+	if (node < 0) {
+		node = fdt_path_offset(dtb, "/chosen");
+		if (node < 0) {
+			ret = -FDT_ERR_NOTFOUND;
+			goto error;
+		}
+	}
+
+	prop = fdt_getprop(dtb, node, "stdout-path", NULL);
+	if (prop == NULL) {
+		ret = -FDT_ERR_NOTFOUND;
+		goto error;
+	}
+
+	/* Parse string serial0:115200n8 */
+	path = strchr(prop, ':');
+	if (!path) {
+		ret = -FDT_ERR_NOTFOUND;
+		goto error;
+	} else {
+
+		baud_rate = strtoul(path + 1, &end, 10);
+		if (baud_rate == 0 && end == path) {
+			ERROR("Conversion error occurred: %d\n", baud_rate);
+			ret = -FDT_ERR_NOTFOUND;
+			goto error;
+		}
+		ret = baud_rate;
+	}
+
+error:
+	return ret;
+}
+
+/**
+ * get_node_status() - Get the DTB node status.
+ * @dtb: Address of the Device Tree Blob (DTB).
+ * @node: Node address in the device tree.
+ *
+ * Return: On success, it returns 1; on failure, it returns an 0.
+ */
+static uint32_t get_node_status(void *dtb, int node)
+{
+	const char *status_cell;
+	uint32_t status = 0;
+
+	status_cell = fdt_getprop(dtb, node, "status", NULL);
+	if (!status_cell || strcmp(status_cell, "okay") == 0) {
+		status = 1;
+	} else {
+		status = 0;
+	}
+
+	return status;
+}
+
+/**
+ * fdt_add_uart_info() - Add DTB information to a UART structure.
+ * @info: Pointer to the UART information structure.
+ * @node: Node address in the device tree.
+ * @dtb: Address of the Device Tree Blob(DTB).
+ *
+ * Return: On success, it returns 1; on failure, it returns an 0.
+ */
+static uint32_t fdt_add_uart_info(dt_uart_info_t *info, int node, void *dtb)
+{
+	uintptr_t base_addr;
+	const char *com;
+	uint32_t ret = 0;
+
+	com = fdt_getprop(dtb, node, "compatible", NULL);
+	if (com != NULL) {
+		strlcpy(info->compatible, com, sizeof(info->compatible));
+	} else {
+		ERROR("Compatible property not found in DTB node\n");
+		ret  = -FDT_ERR_NOTFOUND;
+		goto error;
+	}
+
+	ret = fdt_get_reg_props_by_index(dtb, node, 0, &base_addr, NULL);
+	if (ret >= 0) {
+		info->base = base_addr;
+	} else {
+		ERROR("Failed to retrieve base address. Error code: %d\n", ret);
+		ret  = -FDT_ERR_NOTFOUND;
+		goto error;
+	}
+
+	info->status = get_node_status(dtb, node);
+	info->baud_rate = get_baudrate(dtb);
+
+error:
+	return ret;
+}
+
+/**
+ * fdt_get_uart_info() - Get the uart information form DTB.
+ * @info: Pointer to the UART information structure.
+ *
+ * Return: On success, it returns 0; on failure, it returns an error+reason.
+ */
+static int fdt_get_uart_info(dt_uart_info_t *info)
+{
+	int node, ret = 0;
+	void *dtb = (void *)XILINX_OF_BOARD_DTB_ADDR;
+
+	if (fdt_check_header(dtb) != 0) {
+		ERROR("Can't read DT at %p\n", dtb);
+		ret  = -FDT_ERR_NOTFOUND;
+		goto error;
+	}
+
+	ret = fdt_open_into(dtb, dtb, XILINX_OF_BOARD_DTB_MAX_SIZE);
+	if (ret < 0) {
+		ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret);
+		ret  = -FDT_ERR_NOTFOUND;
+		goto error;
+	}
+
+	node = fdt_get_stdout_node_offset(dtb);
+	if (node < 0) {
+		ERROR("DT get stdout node failed : %d\n", node);
+		ret  = -FDT_ERR_NOTFOUND;
+		goto error;
+	}
+
+	ret = fdt_add_uart_info(info, node, dtb);
+	if (ret < 0) {
+		ERROR("Failed to add DT UART info: %d\n", ret);
+		ret  = -FDT_ERR_NOTFOUND;
+		goto error;
+	}
+
+error:
+	return ret;
+}
+
+/**
+ * check_fdt_uart_info() - Check early uart info with DTB uart info.
+ * @info: Pointer to the UART information structure.
+ *
+ * Return: On success, it returns 0; on failure, it returns an error+reason.
+ */
+static int check_fdt_uart_info(dt_uart_info_t *info)
+{
+	uint32_t ret = 0;
+
+	if (info->status == 0) {
+		ret = -ENODEV;
+		goto error;
+	}
+
+	if ((info->base == console.base) &&
+	   (info->baud_rate == UART_BAUDRATE) && !CONSOLE_IS(dcc)) {
+		ret = -ENODEV;
+		goto error;
+	}
+
+error:
+	return ret;
+}
+
+/**
+ * console_boot_end() - Unregister the console_t instance form the console list.
+ * @boot_console: Pointer to the console information structure.
+ */
+static void console_boot_end(console_t *boot_console)
+{
+	if (CONSOLE_IS(dcc)) {
+		console_dcc_unregister();
+	} else {
+		console_flush();
+		(void)console_unregister(boot_console);
+	}
+}
+
+/**
+ * setup_runtime_console() - Registers the runtime uart with console list.
+ * @clock: UART clock.
+ * @info: Pointer to the UART information structure.
+ */
+static void setup_runtime_console(uint32_t clock, dt_uart_info_t *info)
+{
+	static console_t bl31_runtime_console;
+	uint32_t rc;
+
+#if defined(PLAT_zynqmp)
+	rc = console_cdns_register(info->base,
+				   clock,
+				   info->baud_rate,
+				   &bl31_runtime_console);
+#else
+	rc = console_pl011_register(info->base,
+				    clock,
+				    info->baud_rate,
+				    &bl31_runtime_console);
+#endif
+	if (rc == 0) {
+		panic();
+	}
+
+	console_set_scope(&bl31_runtime_console,
+			  CONSOLE_FLAG_BOOT | CONSOLE_FLAG_RUNTIME |
+			  CONSOLE_FLAG_CRASH);
+}
+
+
+/**
+ * runtime_console_init() - Initializes the run time console information.
+ * @uart_info: Pointer to the UART information structure.
+ * @bl31_boot_console: Pointer to the console information structure.
+ * @clock: UART clock.
+ *
+ * Return: On success, it returns 0; on failure, it returns an error+reason;
+ */
+static int32_t runtime_console_init(dt_uart_info_t *uart_info,
+			  console_t *bl31_boot_console,
+			  uint32_t clock)
+{
+	int32_t rc = 0;
+
+	/* Parse UART information from Device Tree Blob (DTB) */
+	rc = fdt_get_uart_info(uart_info);
+	if (rc < 0) {
+		rc = -FDT_ERR_NOTFOUND;
+	}
+
+	if (strncmp(uart_info->compatible, DT_UART_COMPAT,
+		   strlen(DT_UART_COMPAT)) == 0) {
+
+		if (check_fdt_uart_info(uart_info) == 0) {
+			setup_runtime_console(clock, uart_info);
+			console_boot_end(bl31_boot_console);
+			INFO("Runtime console setup\n");
+		} else {
+			INFO("Early console and DTB console are same\n");
+		}
+	} else if (strncmp(uart_info->compatible, DT_UART_DCC_COMPAT,
+			  strlen(DT_UART_DCC_COMPAT)) == 0) {
+		rc = console_dcc_register();
+		if (rc == 0) {
+			panic();
+		}
+		console_boot_end(bl31_boot_console);
+	} else {
+		WARN("BL31: No console device found in DT.\n");
+	}
+
+	return rc;
+}
+#endif
+
+void setup_console(void)
+{
+	uint32_t rc;
+	uint32_t uart_clk = get_uart_clk();
+
+#if defined(PLAT_zynqmp)
+	if (CONSOLE_IS(cadence) || (CONSOLE_IS(cadence1))) {
+		rc = console_cdns_register(UART_BASE,
+					   uart_clk,
+					   UART_BAUDRATE,
+					   &console);
+		if (rc == 0) {
+			panic();
+		}
+
+		console_set_scope(&console, CONSOLE_FLAG_BOOT |
+				  CONSOLE_FLAG_RUNTIME | CONSOLE_FLAG_CRASH);
+	}
+#else
+	if (CONSOLE_IS(pl011) || (CONSOLE_IS(pl011_1))) {
+		/* Initialize the console to provide early debug support */
+		rc = console_pl011_register((uint32_t)UART_BASE,
+					   uart_clk,
+					   (uint32_t)UART_BAUDRATE,
+					   &console);
+		if (rc == 0) {
+			panic();
+		}
+
+		console_set_scope(&console, CONSOLE_FLAG_BOOT |
+				  CONSOLE_FLAG_RUNTIME | CONSOLE_FLAG_CRASH);
+	}
+#endif
+	if (CONSOLE_IS(dcc)) {
+		/* Initialize the dcc console for debug */
+		rc = console_dcc_register();
+		if (rc == 0) {
+			panic();
+		}
+	}
+	INFO("BL31: Early console setup\n");
+
+#if (defined(XILINX_OF_BOARD_DTB_ADDR) && !IS_TFA_IN_OCM(BL31_BASE))
+	static dt_uart_info_t uart_info = {0};
+
+	/* Initialize the runtime console using UART information from the DTB */
+	rc = runtime_console_init(&uart_info, &console, uart_clk);
+	if (rc < 0) {
+		ERROR("Failed to initialize runtime console: %d\n", rc);
+	}
+#endif
+}

plat/xilinx/zynqmp/bl31_zynqmp_setup.c

@@ -13,12 +13,11 @@
 #include <common/debug.h>
 #include <common/fdt_fixup.h>
 #include <common/fdt_wrappers.h>
-#include <drivers/arm/dcc.h>
-#include <drivers/console.h>
 #include <lib/mmio.h>
 #include <libfdt.h>
 #include <plat/arm/common/plat_arm.h>
 #include <plat/common/platform.h>
+#include <plat_console.h>
 
 #include <custom_svc.h>
 #include <plat_fdt.h>
@@ -74,25 +73,8 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 {
 	uint64_t tfa_handoff_addr;
 
-	if (CONSOLE_IS(cadence) || (CONSOLE_IS(cadence1))) {
+	setup_console();
-		/* Register the console to provide early debug support */
+
-		static console_t bl31_boot_console;
-		(void)console_cdns_register(UART_BASE,
-					       get_uart_clk(),
-					       UART_BAUDRATE,
-					       &bl31_boot_console);
-		console_set_scope(&bl31_boot_console,
-				  CONSOLE_FLAG_RUNTIME | CONSOLE_FLAG_BOOT |
-				  CONSOLE_FLAG_CRASH);
-	} else if (CONSOLE_IS(dcc)) {
-		/* Initialize the dcc console for debug */
-		int32_t rc = console_dcc_register();
-		if (rc == 0) {
-			panic();
-		}
-	} else {
-		/* No console device found. */
-	}
 	/* Initialize the platform config for future decision making */
 	zynqmp_config_setup();
 

plat/xilinx/zynqmp/platform.mk

@@ -124,9 +124,11 @@ BL31_SOURCES		+=	drivers/arm/cci/cci.c				\
 				lib/cpus/aarch64/cortex_a53.S			\
 				plat/common/plat_psci_common.c			\
 				common/fdt_fixup.c				\
+				common/fdt_wrappers.c				\
 				${LIBFDT_SRCS}					\
 				plat/xilinx/common/ipi_mailbox_service/ipi_mailbox_svc.c \
 				plat/xilinx/common/plat_startup.c		\
+				plat/xilinx/common/plat_console.c		\
 				plat/xilinx/common/plat_fdt.c			\
 				plat/xilinx/zynqmp/bl31_zynqmp_setup.c		\
 				plat/xilinx/zynqmp/plat_psci.c			\