state: add framework for persistent state handling

This patch adds a framework to describe, access, store and restore a set of
variables. A state variable set can be fully described in a devicetree node.
This node could be part of the regular devicetree blob or it could be an extra
devicetree solely for the state. The state variable set contains variables of
different types and a place to store the variable set.

For more information see:
    Documentation/devicetree/bindings/barebox/barebox,state.rst

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 77 insertions, 0 deletions

diff --git a/commands/state.c b/commands/state.c
new file mode 100644
index 0000000000..82c29d00c8
--- /dev/null
+++ b/commands/state.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2012 Jan Luebbe <j.luebbe@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <common.h>
+#include <getopt.h>
+#include <command.h>
+#include <state.h>
+
+static int do_state(int argc, char *argv[])
+{
+	int opt, ret = 0;
+	struct state *state = NULL;
+	int do_save = 0, do_load = 0;
+	const char *statename = "state";
+
+	while ((opt = getopt(argc, argv, "sl")) > 0) {
+		switch (opt) {
+		case 's':
+			do_save = 1;
+			break;
+		case 'l':
+			do_load = 1;
+			break;
+		default:
+			return COMMAND_ERROR_USAGE;
+		}
+	}
+
+	if (do_save && do_load)
+		return COMMAND_ERROR_USAGE;
+
+	if (!do_save && !do_load) {
+		state_info();
+		return 0;
+	}
+
+	if (optind < argc)
+		statename = argv[optind];
+
+	state = state_by_name(statename);
+	if (!state) {
+		printf("cannot find state %s\n", statename);
+		return -ENOENT;
+	}
+
+	if (do_save)
+		ret = state_save(state);
+	else if (do_load)
+		ret = state_load(state);
+
+	return ret;
+}
+
+static const __maybe_unused char cmd_state_help[] =
+"Usage: state [OPTIONS] [STATENAME]\n"
+"\n"
+"options:\n"
+"-s        save state\n"
+"-l        load state\n";
+
+BAREBOX_CMD_START(state)
+	.cmd		= do_state,
+	BAREBOX_CMD_DESC("handle state information")
+	BAREBOX_CMD_GROUP(CMD_GRP_MISC)
+	BAREBOX_CMD_HELP(cmd_state_help)
+BAREBOX_CMD_END