1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Copyright (C) 2022, Microchip
 4 */
 5
 6#include <linux/arm-smccc.h>
 7#include <linux/of.h>
 8
 9#include "sam_secure.h"
10
11static bool optee_available;
12
13#define SAM_SIP_SMC_STD_CALL_VAL(func_num) \
14	ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, ARM_SMCCC_SMC_32, \
15	ARM_SMCCC_OWNER_SIP, (func_num))
16
17struct arm_smccc_res sam_smccc_call(u32 fn, u32 arg0, u32 arg1)
18{
19	struct arm_smccc_res res = {.a0 = -1};
20
21	if (WARN_ON(!optee_available))
22		return res;
23
24	arm_smccc_smc(SAM_SIP_SMC_STD_CALL_VAL(fn), arg0, arg1, 0, 0, 0, 0, 0,
25		      &res);
26
27	return res;
28}
29
30bool sam_linux_is_optee_available(void)
31{
32	/* If optee has been detected, then we are running in normal world */
33	return optee_available;
34}
35
36void __init sam_secure_init(void)
37{
38	struct device_node *np;
39
40	/*
41	 * We only check that the OP-TEE node is present and available. The
42	 * OP-TEE kernel driver is not needed for the type of interaction made
43	 * with OP-TEE here so the driver's status is not checked.
44	 */
45	np = of_find_node_by_path("/firmware/optee");
46	if (np && of_device_is_available(np))
47		optee_available = true;
48	of_node_put(np);
49
50	if (optee_available)
51		pr_info("Running under OP-TEE firmware\n");
52}