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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (c) 2017, Microchip Technology Inc.
4 * Author: Tudor Ambarus <tudor.ambarus@microchip.com>
5 */
6
7#ifndef __ATMEL_ECC_H__
8#define __ATMEL_ECC_H__
9
10#define ATMEL_ECC_PRIORITY 300
11
12#define COMMAND 0x03 /* packet function */
13#define SLEEP_TOKEN 0x01
14#define WAKE_TOKEN_MAX_SIZE 8
15
16/* Definitions of Data and Command sizes */
17#define WORD_ADDR_SIZE 1
18#define COUNT_SIZE 1
19#define CRC_SIZE 2
20#define CMD_OVERHEAD_SIZE (COUNT_SIZE + CRC_SIZE)
21
22/* size in bytes of the n prime */
23#define ATMEL_ECC_NIST_P256_N_SIZE 32
24#define ATMEL_ECC_PUBKEY_SIZE (2 * ATMEL_ECC_NIST_P256_N_SIZE)
25
26#define STATUS_RSP_SIZE 4
27#define ECDH_RSP_SIZE (32 + CMD_OVERHEAD_SIZE)
28#define GENKEY_RSP_SIZE (ATMEL_ECC_PUBKEY_SIZE + \
29 CMD_OVERHEAD_SIZE)
30#define READ_RSP_SIZE (4 + CMD_OVERHEAD_SIZE)
31#define MAX_RSP_SIZE GENKEY_RSP_SIZE
32
33/**
34 * atmel_ecc_cmd - structure used for communicating with the device.
35 * @word_addr: indicates the function of the packet sent to the device. This
36 * byte should have a value of COMMAND for normal operation.
37 * @count : number of bytes to be transferred to (or from) the device.
38 * @opcode : the command code.
39 * @param1 : the first parameter; always present.
40 * @param2 : the second parameter; always present.
41 * @data : optional remaining input data. Includes a 2-byte CRC.
42 * @rxsize : size of the data received from i2c client.
43 * @msecs : command execution time in milliseconds
44 */
45struct atmel_ecc_cmd {
46 u8 word_addr;
47 u8 count;
48 u8 opcode;
49 u8 param1;
50 u16 param2;
51 u8 data[MAX_RSP_SIZE];
52 u8 msecs;
53 u16 rxsize;
54} __packed;
55
56/* Status/Error codes */
57#define STATUS_SIZE 0x04
58#define STATUS_NOERR 0x00
59#define STATUS_WAKE_SUCCESSFUL 0x11
60
61static const struct {
62 u8 value;
63 const char *error_text;
64} error_list[] = {
65 { 0x01, "CheckMac or Verify miscompare" },
66 { 0x03, "Parse Error" },
67 { 0x05, "ECC Fault" },
68 { 0x0F, "Execution Error" },
69 { 0xEE, "Watchdog about to expire" },
70 { 0xFF, "CRC or other communication error" },
71};
72
73/* Definitions for eeprom organization */
74#define CONFIG_ZONE 0
75
76/* Definitions for Indexes common to all commands */
77#define RSP_DATA_IDX 1 /* buffer index of data in response */
78#define DATA_SLOT_2 2 /* used for ECDH private key */
79
80/* Definitions for the device lock state */
81#define DEVICE_LOCK_ADDR 0x15
82#define LOCK_VALUE_IDX (RSP_DATA_IDX + 2)
83#define LOCK_CONFIG_IDX (RSP_DATA_IDX + 3)
84
85/*
86 * Wake High delay to data communication (microseconds). SDA should be stable
87 * high for this entire duration.
88 */
89#define TWHI_MIN 1500
90#define TWHI_MAX 1550
91
92/* Wake Low duration */
93#define TWLO_USEC 60
94
95/* Command execution time (milliseconds) */
96#define MAX_EXEC_TIME_ECDH 58
97#define MAX_EXEC_TIME_GENKEY 115
98#define MAX_EXEC_TIME_READ 1
99
100/* Command opcode */
101#define OPCODE_ECDH 0x43
102#define OPCODE_GENKEY 0x40
103#define OPCODE_READ 0x02
104
105/* Definitions for the READ Command */
106#define READ_COUNT 7
107
108/* Definitions for the GenKey Command */
109#define GENKEY_COUNT 7
110#define GENKEY_MODE_PRIVATE 0x04
111
112/* Definitions for the ECDH Command */
113#define ECDH_COUNT 71
114#define ECDH_PREFIX_MODE 0x00
115
116#endif /* __ATMEL_ECC_H__ */