Re: [PATCH V2 01/10] board: ti: common: Introduce a common fdt ops library

Nishanth Menon nm@ti.com writes:

Introduce a common fdt operations library for basic device tree operations that are common between various boards.

The first library to introduce here is the capability to set up fdtfile as a standard variable as part of board identification rather than depend on scripted ifdeffery.

Signed-off-by: Nishanth Menon nm@ti.com

Changes Since v1:

• s/TI_EVM_FDT_FOLDER_PATH/TI_FDT_FOLDER_PATH s/name_fdt/board_name s/TI_NAME_FDT_MAX/TI_BOARD_NAME_MAX
• Comment updates in various places for review clarification.
• Still maintain the fall back using CONFIG_DEFAULT_DEVICE_TREE for reasons explained in review comment response.
• Added a specific u-boot version number for deprecation of legacy env variables.

V1: https://lore.kernel.org/r/20240108173301.2692332-2-nm@ti.com

board/ti/common/Kconfig | 12 ++++++++ board/ti/common/Makefile | 1 + board/ti/common/fdt_ops.c | 64 +++++++++++++++++++++++++++++++++++++++ board/ti/common/fdt_ops.h | 42 +++++++++++++++++++++++++ 4 files changed, 119 insertions(+) create mode 100644 board/ti/common/fdt_ops.c create mode 100644 board/ti/common/fdt_ops.h

diff --git a/board/ti/common/Kconfig b/board/ti/common/Kconfig index 49edd98014ab..de44e4de2115 100644 --- a/board/ti/common/Kconfig +++ b/board/ti/common/Kconfig @@ -49,3 +49,15 @@ config TI_COMMON_CMD_OPTIONS imply CMD_SPI imply CMD_TIME imply CMD_USB if USB

+config TI_FDT_FOLDER_PATH

• string "Location of Folder path where dtb is present"
• default "ti/davinci" if ARCH_DAVINCI
• default "ti/keystone" if ARCH_KEYSTONE
• default "ti/omap" if ARCH_OMAP2PLUS
• default "ti" if ARCH_K3
• depends on ARCH_DAVINCI || ARCH_KEYSTONE || ARCH_OMAP2PLUS || ARCH_K3
• help

•   Folder path for kernel device tree default.
  

•   This is used along with fdtfile path to locate the kernel
  

•   device tree blob.
  

diff --git a/board/ti/common/Makefile b/board/ti/common/Makefile index 26bf12e2e6d5..5ac361ba7fcf 100644 --- a/board/ti/common/Makefile +++ b/board/ti/common/Makefile @@ -3,3 +3,4 @@

obj-${CONFIG_TI_I2C_BOARD_DETECT} += board_detect.o obj-${CONFIG_CMD_EXTENSION} += cape_detect.o +obj-${CONFIG_OF_LIBFDT} += fdt_ops.o diff --git a/board/ti/common/fdt_ops.c b/board/ti/common/fdt_ops.c new file mode 100644 index 000000000000..eb917be9e0da --- /dev/null +++ b/board/ti/common/fdt_ops.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*

• • Library to support FDT file operations which are common
• • Copyright (C) 2024 Texas Instruments Incorporated - https://www.ti.com/
• */

+#include <env.h> +#include <vsprintf.h> +#include "fdt_ops.h"

+void ti_set_fdt_env(const char *board_name, struct ti_fdt_map *fdt_map) +{

• char *fdt_file_name = NULL;
• char fdtfile[TI_FDT_FILE_MAX];
• if (board_name) {

• while (fdt_map) {
  

• 	/* Check for NULL terminator in the list */
  

• 	if (!fdt_map->board_name)
  

• 		break;
  

• 	if (!strncmp(fdt_map->board_name, board_name, TI_BOARD_NAME_MAX)) {
  

• 		fdt_file_name = fdt_map->fdt_file_name;
  

• 		break;
  

• 	}
  

• 	fdt_map++;
  

• }
  

• }
• /* match not found OR null board_name */
• if (!fdt_file_name) {

• /*
  

•  * Prioritize CONFIG_DEFAULT_FDT_FILE - if that is not defined,
  

•  * or is empty, then use CONFIG_DEFAULT_DEVICE_TREE
  

•  */
  

+#ifdef CONFIG_DEFAULT_FDT_FILE

• if (strlen(CONFIG_DEFAULT_FDT_FILE)) {
  

• 	snprintf(fdtfile, sizeof(fdtfile), "%s/%s",
  

• 		 CONFIG_TI_FDT_FOLDER_PATH, CONFIG_DEFAULT_FDT_FILE);
  

• } else
  

+#endif

• {
  

• 	snprintf(fdtfile, sizeof(fdtfile), "%s/%s.dtb",
  

• 		 CONFIG_TI_FDT_FOLDER_PATH, CONFIG_DEFAULT_DEVICE_TREE);
  

• }
  

• } else {

• snprintf(fdtfile, sizeof(fdtfile), "%s/%s", CONFIG_TI_FDT_FOLDER_PATH,
  

• 	 fdt_file_name);
  

• }
• env_set("fdtfile", fdtfile);
• /*

• * XXX: DEPRECATION WARNING: 2 u-boot versions (2024.10).
  

• *
  

• * Maintain compatibility with downstream scripts that may be using
  

• * name_fdt
  

• */
  

• if (board_name)

• env_set("name_fdt", fdtfile);
  

• /* Also set the findfdt legacy script to warn users to stop using this */
• env_set("findfdt",

• "echo WARN: fdtfile already set. Stop using findfdt in script");
  

+} diff --git a/board/ti/common/fdt_ops.h b/board/ti/common/fdt_ops.h new file mode 100644 index 000000000000..5d304994fb6e --- /dev/null +++ b/board/ti/common/fdt_ops.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/*

• • Library to support common device tree manipulation for TI EVMs
• • Copyright (C) 2024 Texas Instruments Incorporated - https://www.ti.com
• */

+#ifndef __FDT_OPS_H +#define __FDT_OPS_H

+#define TI_BOARD_NAME_MAX 20 +#define TI_FDT_FILE_MAX 200

+/**

• • struct ti_fdt_map - mapping of device tree blob name to board name
• • @board_name: board_name up to TI_BOARD_NAME_MAX long
• • @fdt_file_name: device tree blob name as described by kernel
• */

+struct ti_fdt_map {

• const char *board_name;
• char *fdt_file_name;

+};

+/**

• • ti_set_fdt_env - Find the correct device tree file name based on the
• • board name and set 'fdtfile' env variable with correct folder
• • structure appropriate to the architecture and Linux kernel's
• • 'make install_dtbs' conventions. This function is invoked typically
• • as part of board_late_init.
• • fdt name is picked by:
• • a) If a board name match is found, use the match
• • b) If not, CONFIG_DEFAULT_FDT_FILE (Boot OS device tree) if that is defined
• • and not null
• • c) If not, Use CONFIG_DEFAULT_DEVICE_TREE (DT control for bootloader)
• • @board_name: match to search with (max of TI_BOARD_NAME_MAX chars)
• • @fdt_map: NULL terminated array of device tree file name matches.
• */

+void ti_set_fdt_env(const char *board_name, struct ti_fdt_map *fdt_map);

+#endif /* __FDT_OPS_H */

2.43.0

Reviewed-by: Jonathan Humphreys j-humphreys@ti.com