cmd: Add support for optee commands

Add the basic 'hello world ta' command which increment
of the value passed. This provides easy test for
establishing a session with OP-TEE TA and verify.

It includes following "hello world ta" subcommands:
optee hello; default value '0' is passed and gets incremented.
optee hello <value>; value to increment via OP-TEE HELLO
WORLD TA.

To enable the OP-TEE side HELLO WORLD example please refer
https://optee.readthedocs.io/en/latest/building/gits/optee_examples/optee_examples.html

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>

cmd/Kconfig

@@ -1446,6 +1446,12 @@ config CMD_OPTEE_RPMB
 	  in the Replay Protection Memory Block partition in eMMC by
 	  using Persistent Objects in OPTEE
 
+config CMD_OPTEE
+	bool "Enable OP-TEE commands"
+	depends on OPTEE
+	help
+	 OP-TEE commands support.
+
 config CMD_MTD
 	bool "mtd"
 	depends on MTD

cmd/Makefile

@@ -118,6 +118,7 @@ obj-$(CONFIG_CMD_PAUSE) += pause.o
 obj-$(CONFIG_CMD_SLEEP) += sleep.o
 obj-$(CONFIG_CMD_MMC) += mmc.o
 obj-$(CONFIG_CMD_OPTEE_RPMB) += optee_rpmb.o
+obj-$(CONFIG_CMD_OPTEE) += optee.o
 obj-$(CONFIG_CMD_MP) += mp.o
 obj-$(CONFIG_CMD_MTD) += mtd.o
 obj-$(CONFIG_CMD_MTDPARTS) += mtdparts.o

cmd/optee.c

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) Copyright 2024, Advanced Micro Devices, Inc.
+ */
+#include <command.h>
+#include <errno.h>
+#include <tee.h>
+#include <vsprintf.h>
+
+#define TA_HELLO_WORLD_CMD_INC_VALUE 0
+/* This needs to match the UUID of the Hello World TA. */
+#define TA_HELLO_WORLD_UUID \
+	{ 0x8aaaf200, 0x2450, 0x11e4, \
+	{ 0xab, 0xe2, 0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b} }
+
+static int hello_world_ta(unsigned int value)
+{
+	const struct tee_optee_ta_uuid uuid = TA_HELLO_WORLD_UUID;
+	struct tee_open_session_arg session_arg;
+	struct udevice *tee = NULL;
+	struct tee_invoke_arg arg;
+	struct tee_param param[2];
+	int rc;
+
+	tee = tee_find_device(tee, NULL, NULL, NULL);
+	if (!tee)
+		return -ENODEV;
+
+	memset(&session_arg, 0, sizeof(session_arg));
+	tee_optee_ta_uuid_to_octets(session_arg.uuid, &uuid);
+	rc = tee_open_session(tee, &session_arg, 0, NULL);
+	if (rc) {
+		printf("tee_open_session(): failed(%d)\n", rc);
+		return rc;
+	}
+
+	arg.func = TA_HELLO_WORLD_CMD_INC_VALUE;
+	arg.session = session_arg.session;
+
+	param[0].attr = TEE_PARAM_ATTR_TYPE_VALUE_INOUT;
+	param[0].u.value.a = value;
+
+	printf("Value before: 0x%x\n", (int)param[0].u.value.a);
+	printf("Calling TA\n");
+	tee_invoke_func(tee, &arg, 1, param);
+
+	printf("Value after: 0x%x\n", (int)param[0].u.value.a);
+	return tee_close_session(tee, session_arg.session);
+}
+
+static int do_optee_hello_world_ta(struct cmd_tbl *cmdtp, int flag, int argc,
+				   char * const argv[])
+{
+	int ret, value = 0;
+
+	if (strcmp(argv[1], NULL))
+		value = hextoul(argv[1], NULL);
+
+	ret = hello_world_ta(value);
+	if (ret)
+		return CMD_RET_FAILURE;
+
+	return CMD_RET_SUCCESS;
+}
+
+U_BOOT_LONGHELP(optee,
+	"hello [<value>]   Invoke the OP-TEE 'Hello World' TA\n");
+
+U_BOOT_CMD_WITH_SUBCMDS(optee, "OP-TEE commands", optee_help_text,
+	U_BOOT_SUBCMD_MKENT(hello, 2, 1, do_optee_hello_world_ta));