--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021
+ * Köry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <malloc.h>
+#include <extension_board.h>
+#include <mapmem.h>
+#include <linux/libfdt.h>
+#include <fdt_support.h>
+
+static LIST_HEAD(extension_list);
+
+static int extension_apply(struct extension *extension)
+{
+ char *overlay_cmd;
+ ulong extrasize, overlay_addr;
+ struct fdt_header *blob;
+
+ if (!working_fdt) {
+ printf("No FDT memory address configured. Please configure\n"
+ "the FDT address via \"fdt addr <address>\" command.\n");
+ return CMD_RET_FAILURE;
+ }
+
+ overlay_cmd = env_get("extension_overlay_cmd");
+ if (!overlay_cmd) {
+ printf("Environment extension_overlay_cmd is missing\n");
+ return CMD_RET_FAILURE;
+ }
+
+ overlay_addr = env_get_hex("extension_overlay_addr", 0);
+ if (!overlay_addr) {
+ printf("Environment extension_overlay_addr is missing\n");
+ return CMD_RET_FAILURE;
+ }
+
+ env_set("extension_overlay_name", extension->overlay);
+ if (run_command(overlay_cmd, 0) != 0)
+ return CMD_RET_FAILURE;
+
+ extrasize = env_get_hex("filesize", 0);
+ if (!extrasize)
+ return CMD_RET_FAILURE;
+
+ fdt_shrink_to_minimum(working_fdt, extrasize);
+
+ blob = map_sysmem(overlay_addr, 0);
+ if (!fdt_valid(&blob))
+ return CMD_RET_FAILURE;
+
+ /* apply method prints messages on error */
+ if (fdt_overlay_apply_verbose(working_fdt, blob))
+ return CMD_RET_FAILURE;
+
+ return CMD_RET_SUCCESS;
+}
+
+static int do_extension_list(struct cmd_tbl *cmdtp, int flag,
+ int argc, char *const argv[])
+{
+ int i = 0;
+ struct extension *extension;
+
+ if (list_empty(&extension_list)) {
+ printf("No extension registered - Please run \"extension scan\"\n");
+ return CMD_RET_SUCCESS;
+ }
+
+ list_for_each_entry(extension, &extension_list, list) {
+ printf("Extension %d: %s\n", i++, extension->name);
+ printf("\tManufacturer: \t\t%s\n", extension->owner);
+ printf("\tVersion: \t\t%s\n", extension->version);
+ printf("\tDevicetree overlay: \t%s\n", extension->overlay);
+ printf("\tOther information: \t%s\n", extension->other);
+ }
+ return CMD_RET_SUCCESS;
+}
+
+static int do_extension_scan(struct cmd_tbl *cmdtp, int flag,
+ int argc, char *const argv[])
+{
+ struct extension *extension, *next;
+ int extension_num;
+
+ list_for_each_entry_safe(extension, next, &extension_list, list) {
+ list_del(&extension->list);
+ free(extension);
+ }
+ extension_num = extension_board_scan(&extension_list);
+
+ if (extension_num < 0)
+ return CMD_RET_FAILURE;
+
+ printf("Found %d extension board(s).\n", extension_num);
+
+ return CMD_RET_SUCCESS;
+}
+
+static int do_extension_apply(struct cmd_tbl *cmdtp, int flag,
+ int argc, char *const argv[])
+{
+ struct extension *extension = NULL;
+ struct list_head *entry;
+ int i = 0, extension_id, ret;
+
+ if (argc < 2)
+ return CMD_RET_USAGE;
+
+ if (strcmp(argv[1], "all") == 0) {
+ list_for_each_entry(extension, &extension_list, list) {
+ ret = extension_apply(extension);
+ if (ret != CMD_RET_SUCCESS)
+ break;
+ }
+ } else {
+ extension_id = simple_strtol(argv[1], NULL, 10);
+ list_for_each(entry, &extension_list) {
+ if (i == extension_id) {
+ extension = list_entry(entry, struct extension, list);
+ break;
+ }
+ i++;
+ }
+
+ if (!extension) {
+ printf("Wrong extension number\n");
+ return CMD_RET_FAILURE;
+ }
+
+ ret = extension_apply(extension);
+ }
+
+ return ret;
+}
+
+static struct cmd_tbl cmd_extension[] = {
+ U_BOOT_CMD_MKENT(scan, 1, 1, do_extension_scan, "", ""),
+ U_BOOT_CMD_MKENT(list, 1, 0, do_extension_list, "", ""),
+ U_BOOT_CMD_MKENT(apply, 2, 0, do_extension_apply, "", ""),
+};
+
+static int do_extensionops(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ struct cmd_tbl *cp;
+
+ /* Drop the extension command */
+ argc--;
+ argv++;
+
+ cp = find_cmd_tbl(argv[0], cmd_extension, ARRAY_SIZE(cmd_extension));
+ if (cp)
+ return cp->cmd(cmdtp, flag, argc, argv);
+
+ return CMD_RET_USAGE;
+}
+
+U_BOOT_CMD(extension, 3, 1, do_extensionops,
+ "Extension board management sub system",
+ "scan - scan plugged extension(s) board(s)\n"
+ "extension list - lists available extension(s) board(s)\n"
+ "extension apply <extension number|all> - applies DT overlays corresponding to extension boards\n"
+);
--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0+
+.. Copyright 2021, Kory Maincent <kory.maincent@bootlin.com>
+
+U-Boot extension board usage (CONFIG_EXTENSION)
+===============================================
+
+Synopsis
+--------
+
+::
+
+ extension scan
+ extension list
+ extension apply <extension number|all>
+
+Description
+-----------
+
+The "extension" command proposes a generic U-Boot mechanism to detect
+extension boards connected to the HW platform, and apply the appropriate
+Device Tree overlays depending on the detected extension boards.
+
+The "extension" command comes with three sub-commands:
+
+ - "extension scan" makes the generic code call the board-specific
+ extension_board_scan() function to retrieve the list of detected
+ extension boards.
+
+ - "extension list" allows to list the detected extension boards.
+
+ - "extension apply <number>|all" allows to apply the Device Tree
+ overlay(s) corresponding to one, or all, extension boards
+
+The latter requires two environment variables to exist:
+
+ - extension_overlay_addr: the RAM address where to load the Device
+ Tree overlays
+
+ - extension_overlay_cmd: the U-Boot command to load one overlay.
+ Indeed, the location and mechanism to load DT overlays is very setup
+ specific.
+
+In order to enable this mechanism, board-specific code must implement
+the extension_board_scan() function that fills in a linked list of
+"struct extension", each describing one extension board. In addition,
+the board-specific code must select the SUPPORT_EXTENSION_SCAN Kconfig
+boolean.
+
+Usage example
+-------------
+
+1. Make sure your devicetree is loaded and set as the working fdt tree.
+
+::
+
+ => run loadfdt
+ => fdt addr $fdtaddr
+
+2. Prepare the environment variables
+
+::
+
+ => setenv extension_overlay_addr 0x88080000
+ => setenv extension_overlay_cmd 'load mmc 0:1 ${extension_overlay_addr} /boot/${extension_overlay_name}'
+
+3. Detect the plugged extension board
+
+::
+
+ => extension scan
+
+4. List the plugged extension board information and the devicetree
+ overlay name
+
+::
+
+ => extension list
+
+5. Apply the appropriate devicetree overlay
+
+For apply the selected overlay:
+
+::
+
+ => extension apply 0
+
+For apply all the overlays:
+
+::
+
+ => extension apply all
+
+Simple extension_board_scan function example
+--------------------------------------------
+
+.. code-block:: c
+
+ int extension_board_scan(struct list_head *extension_list)
+ {
+ struct extension *extension;
+
+ extension = calloc(1, sizeof(struct extension));
+ snprintf(extension->overlay, sizeof(extension->overlay), "overlay.dtbo");
+ snprintf(extension->name, sizeof(extension->name), "extension board");
+ snprintf(extension->owner, sizeof(extension->owner), "sandbox");
+ snprintf(extension->version, sizeof(extension->version), "1.1");
+ snprintf(extension->other, sizeof(extension->other), "Extension board information");
+ list_add_tail(&extension->list, extension_list);
+
+ return 1;
+ }
projects / u-boot.git / commitdiff
