1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2023 SberDevices, Inc.
4  *
5  * Author: Alexey Romanov <avromanov@salutedevices.ru>
6  */
7 
8 #ifndef __SM_H__
9 #define __SM_H__
10 
11 /*
12  * NOTE: UCLASS_SM is designed with the idea that
13  * each driver should convert @cmd to some raw
14  * value, which is known only for driver, and set this
15  * value to the first element of the @args->regs array.
16  * Therefore, it is necessary to pass the remaining
17  * arguments starting at index = 1. Anyway, driver
18  * implementation may vary, so, please, check the specific
19  * implementation of the driver you are using.
20  */
21 
22 #include <linux/types.h>
23 #include <asm/ptrace.h>
24 
25 struct udevice;
26 
27 /**
28  * sm_call - generic SMC call to the secure-monitor
29  *
30  * @dev:	Pointer to UCLASS_SM device
31  * @cmd_index:	Index of the SMC function ID
32  * @smc_ret:	Returned value from secure world
33  * @args:	SMC arguments
34  *
35  * @return:	0 on success, a negative value on error
36  */
37 int sm_call(struct udevice *dev, u32 cmd, s32 *ret, struct pt_regs *args);
38 
39 /**
40  * sm_call_read - retrieve data from secure-monitor
41  *
42  * @dev:	Pointer to UCLASS_MESON_SM device
43  * @buffer:	Buffer to store the retrieved data
44  * @size:	Size of the buffer
45  * @cmd:	Index of the SMC function ID
46  * @args:	SMC arguments
47  *
48  * @return:	size of read data on success, a negative value on error
49  */
50 int sm_call_read(struct udevice *dev, void *buffer, size_t size,
51 		 u32 cmd, struct pt_regs *args);
52 
53 /**
54  * sm_call_write - send data to secure-monitor
55  *
56  * @dev:	Pointer to UCLASS_SM device
57  * @buffer:	Buffer containing data to send
58  * @size:	Size of the buffer
59  * @cmd:	Index of the SMC function ID
60  * @args:	SMC arguments
61  *
62  * @return:	size of sent data on success, a negative value on error
63  */
64 int sm_call_write(struct udevice *dev, void *buffer, size_t size,
65 		  u32 cmd, struct pt_regs *args);
66 
67 #endif /* __SM_H__ */
68