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820684cc | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
11105693 TDA |
2 | /* |
3 | * Copyright (c) 2017, Microchip Technology Inc. | |
4 | * Author: Tudor Ambarus <tudor.ambarus@microchip.com> | |
11105693 TDA |
5 | */ |
6 | ||
c34a3201 AB |
7 | #ifndef __ATMEL_I2C_H__ |
8 | #define __ATMEL_I2C_H__ | |
11105693 | 9 | |
da001fb6 | 10 | #include <linux/hw_random.h> |
49d22167 | 11 | #include <linux/types.h> |
da001fb6 | 12 | |
11105693 TDA |
13 | #define ATMEL_ECC_PRIORITY 300 |
14 | ||
15 | #define COMMAND 0x03 /* packet function */ | |
16 | #define SLEEP_TOKEN 0x01 | |
17 | #define WAKE_TOKEN_MAX_SIZE 8 | |
18 | ||
19 | /* Definitions of Data and Command sizes */ | |
20 | #define WORD_ADDR_SIZE 1 | |
21 | #define COUNT_SIZE 1 | |
22 | #define CRC_SIZE 2 | |
23 | #define CMD_OVERHEAD_SIZE (COUNT_SIZE + CRC_SIZE) | |
24 | ||
25 | /* size in bytes of the n prime */ | |
26 | #define ATMEL_ECC_NIST_P256_N_SIZE 32 | |
27 | #define ATMEL_ECC_PUBKEY_SIZE (2 * ATMEL_ECC_NIST_P256_N_SIZE) | |
28 | ||
29 | #define STATUS_RSP_SIZE 4 | |
30 | #define ECDH_RSP_SIZE (32 + CMD_OVERHEAD_SIZE) | |
31 | #define GENKEY_RSP_SIZE (ATMEL_ECC_PUBKEY_SIZE + \ | |
32 | CMD_OVERHEAD_SIZE) | |
33 | #define READ_RSP_SIZE (4 + CMD_OVERHEAD_SIZE) | |
da001fb6 | 34 | #define RANDOM_RSP_SIZE (32 + CMD_OVERHEAD_SIZE) |
11105693 TDA |
35 | #define MAX_RSP_SIZE GENKEY_RSP_SIZE |
36 | ||
37 | /** | |
c34a3201 | 38 | * atmel_i2c_cmd - structure used for communicating with the device. |
11105693 TDA |
39 | * @word_addr: indicates the function of the packet sent to the device. This |
40 | * byte should have a value of COMMAND for normal operation. | |
41 | * @count : number of bytes to be transferred to (or from) the device. | |
42 | * @opcode : the command code. | |
43 | * @param1 : the first parameter; always present. | |
44 | * @param2 : the second parameter; always present. | |
45 | * @data : optional remaining input data. Includes a 2-byte CRC. | |
46 | * @rxsize : size of the data received from i2c client. | |
47 | * @msecs : command execution time in milliseconds | |
48 | */ | |
c34a3201 | 49 | struct atmel_i2c_cmd { |
11105693 TDA |
50 | u8 word_addr; |
51 | u8 count; | |
52 | u8 opcode; | |
53 | u8 param1; | |
49d22167 | 54 | __le16 param2; |
11105693 TDA |
55 | u8 data[MAX_RSP_SIZE]; |
56 | u8 msecs; | |
57 | u16 rxsize; | |
58 | } __packed; | |
59 | ||
60 | /* Status/Error codes */ | |
61 | #define STATUS_SIZE 0x04 | |
62 | #define STATUS_NOERR 0x00 | |
63 | #define STATUS_WAKE_SUCCESSFUL 0x11 | |
64 | ||
11105693 TDA |
65 | /* Definitions for eeprom organization */ |
66 | #define CONFIG_ZONE 0 | |
67 | ||
68 | /* Definitions for Indexes common to all commands */ | |
69 | #define RSP_DATA_IDX 1 /* buffer index of data in response */ | |
70 | #define DATA_SLOT_2 2 /* used for ECDH private key */ | |
71 | ||
72 | /* Definitions for the device lock state */ | |
73 | #define DEVICE_LOCK_ADDR 0x15 | |
74 | #define LOCK_VALUE_IDX (RSP_DATA_IDX + 2) | |
75 | #define LOCK_CONFIG_IDX (RSP_DATA_IDX + 3) | |
76 | ||
77 | /* | |
78 | * Wake High delay to data communication (microseconds). SDA should be stable | |
79 | * high for this entire duration. | |
80 | */ | |
81 | #define TWHI_MIN 1500 | |
82 | #define TWHI_MAX 1550 | |
83 | ||
84 | /* Wake Low duration */ | |
85 | #define TWLO_USEC 60 | |
86 | ||
87 | /* Command execution time (milliseconds) */ | |
88 | #define MAX_EXEC_TIME_ECDH 58 | |
89 | #define MAX_EXEC_TIME_GENKEY 115 | |
90 | #define MAX_EXEC_TIME_READ 1 | |
da001fb6 | 91 | #define MAX_EXEC_TIME_RANDOM 50 |
11105693 TDA |
92 | |
93 | /* Command opcode */ | |
94 | #define OPCODE_ECDH 0x43 | |
95 | #define OPCODE_GENKEY 0x40 | |
96 | #define OPCODE_READ 0x02 | |
da001fb6 | 97 | #define OPCODE_RANDOM 0x1b |
11105693 TDA |
98 | |
99 | /* Definitions for the READ Command */ | |
100 | #define READ_COUNT 7 | |
101 | ||
da001fb6 AB |
102 | /* Definitions for the RANDOM Command */ |
103 | #define RANDOM_COUNT 7 | |
104 | ||
11105693 TDA |
105 | /* Definitions for the GenKey Command */ |
106 | #define GENKEY_COUNT 7 | |
107 | #define GENKEY_MODE_PRIVATE 0x04 | |
108 | ||
109 | /* Definitions for the ECDH Command */ | |
110 | #define ECDH_COUNT 71 | |
111 | #define ECDH_PREFIX_MODE 0x00 | |
112 | ||
c34a3201 AB |
113 | /* Used for binding tfm objects to i2c clients. */ |
114 | struct atmel_ecc_driver_data { | |
115 | struct list_head i2c_client_list; | |
116 | spinlock_t i2c_list_lock; | |
117 | } ____cacheline_aligned; | |
118 | ||
119 | /** | |
120 | * atmel_i2c_client_priv - i2c_client private data | |
121 | * @client : pointer to i2c client device | |
122 | * @i2c_client_list_node: part of i2c_client_list | |
123 | * @lock : lock for sending i2c commands | |
124 | * @wake_token : wake token array of zeros | |
125 | * @wake_token_sz : size in bytes of the wake_token | |
126 | * @tfm_count : number of active crypto transformations on i2c client | |
127 | * | |
128 | * Reads and writes from/to the i2c client are sequential. The first byte | |
129 | * transmitted to the device is treated as the byte size. Any attempt to send | |
130 | * more than this number of bytes will cause the device to not ACK those bytes. | |
131 | * After the host writes a single command byte to the input buffer, reads are | |
132 | * prohibited until after the device completes command execution. Use a mutex | |
133 | * when sending i2c commands. | |
134 | */ | |
135 | struct atmel_i2c_client_priv { | |
136 | struct i2c_client *client; | |
137 | struct list_head i2c_client_list_node; | |
138 | struct mutex lock; | |
139 | u8 wake_token[WAKE_TOKEN_MAX_SIZE]; | |
140 | size_t wake_token_sz; | |
141 | atomic_t tfm_count ____cacheline_aligned; | |
da001fb6 | 142 | struct hwrng hwrng; |
c34a3201 AB |
143 | }; |
144 | ||
145 | /** | |
146 | * atmel_i2c_work_data - data structure representing the work | |
147 | * @ctx : transformation context. | |
148 | * @cbk : pointer to a callback function to be invoked upon completion of this | |
149 | * request. This has the form: | |
150 | * callback(struct atmel_i2c_work_data *work_data, void *areq, u8 status) | |
151 | * where: | |
152 | * @work_data: data structure representing the work | |
153 | * @areq : optional pointer to an argument passed with the original | |
154 | * request. | |
155 | * @status : status returned from the i2c client device or i2c error. | |
156 | * @areq: optional pointer to a user argument for use at callback time. | |
157 | * @work: describes the task to be executed. | |
158 | * @cmd : structure used for communicating with the device. | |
159 | */ | |
160 | struct atmel_i2c_work_data { | |
161 | void *ctx; | |
162 | struct i2c_client *client; | |
163 | void (*cbk)(struct atmel_i2c_work_data *work_data, void *areq, | |
164 | int status); | |
165 | void *areq; | |
166 | struct work_struct work; | |
167 | struct atmel_i2c_cmd cmd; | |
168 | }; | |
169 | ||
170 | int atmel_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id); | |
171 | ||
172 | void atmel_i2c_enqueue(struct atmel_i2c_work_data *work_data, | |
173 | void (*cbk)(struct atmel_i2c_work_data *work_data, | |
174 | void *areq, int status), | |
175 | void *areq); | |
0a2f4b57 | 176 | void atmel_i2c_flush_queue(void); |
c34a3201 AB |
177 | |
178 | int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd); | |
179 | ||
180 | void atmel_i2c_init_read_cmd(struct atmel_i2c_cmd *cmd); | |
da001fb6 | 181 | void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd); |
c34a3201 AB |
182 | void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid); |
183 | int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd, | |
184 | struct scatterlist *pubkey); | |
185 | ||
186 | #endif /* __ATMEL_I2C_H__ */ |