1 /* 2 * Copyright (c) 2017, Microchip Technology Inc. 3 * Author: Tudor Ambarus <tudor.ambarus@microchip.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 12 * more details. 13 * 14 * You should have received a copy of the GNU General Public License along with 15 * this program. If not, see <http://www.gnu.org/licenses/>. 16 * 17 */ 18 19 #ifndef __ATMEL_ECC_H__ 20 #define __ATMEL_ECC_H__ 21 22 #define ATMEL_ECC_PRIORITY 300 23 24 #define COMMAND 0x03 /* packet function */ 25 #define SLEEP_TOKEN 0x01 26 #define WAKE_TOKEN_MAX_SIZE 8 27 28 /* Definitions of Data and Command sizes */ 29 #define WORD_ADDR_SIZE 1 30 #define COUNT_SIZE 1 31 #define CRC_SIZE 2 32 #define CMD_OVERHEAD_SIZE (COUNT_SIZE + CRC_SIZE) 33 34 /* size in bytes of the n prime */ 35 #define ATMEL_ECC_NIST_P256_N_SIZE 32 36 #define ATMEL_ECC_PUBKEY_SIZE (2 * ATMEL_ECC_NIST_P256_N_SIZE) 37 38 #define STATUS_RSP_SIZE 4 39 #define ECDH_RSP_SIZE (32 + CMD_OVERHEAD_SIZE) 40 #define GENKEY_RSP_SIZE (ATMEL_ECC_PUBKEY_SIZE + \ 41 CMD_OVERHEAD_SIZE) 42 #define READ_RSP_SIZE (4 + CMD_OVERHEAD_SIZE) 43 #define MAX_RSP_SIZE GENKEY_RSP_SIZE 44 45 /** 46 * atmel_ecc_cmd - structure used for communicating with the device. 47 * @word_addr: indicates the function of the packet sent to the device. This 48 * byte should have a value of COMMAND for normal operation. 49 * @count : number of bytes to be transferred to (or from) the device. 50 * @opcode : the command code. 51 * @param1 : the first parameter; always present. 52 * @param2 : the second parameter; always present. 53 * @data : optional remaining input data. Includes a 2-byte CRC. 54 * @rxsize : size of the data received from i2c client. 55 * @msecs : command execution time in milliseconds 56 */ 57 struct atmel_ecc_cmd { 58 u8 word_addr; 59 u8 count; 60 u8 opcode; 61 u8 param1; 62 u16 param2; 63 u8 data[MAX_RSP_SIZE]; 64 u8 msecs; 65 u16 rxsize; 66 } __packed; 67 68 /* Status/Error codes */ 69 #define STATUS_SIZE 0x04 70 #define STATUS_NOERR 0x00 71 #define STATUS_WAKE_SUCCESSFUL 0x11 72 73 static const struct { 74 u8 value; 75 const char *error_text; 76 } error_list[] = { 77 { 0x01, "CheckMac or Verify miscompare" }, 78 { 0x03, "Parse Error" }, 79 { 0x05, "ECC Fault" }, 80 { 0x0F, "Execution Error" }, 81 { 0xEE, "Watchdog about to expire" }, 82 { 0xFF, "CRC or other communication error" }, 83 }; 84 85 /* Definitions for eeprom organization */ 86 #define CONFIG_ZONE 0 87 88 /* Definitions for Indexes common to all commands */ 89 #define RSP_DATA_IDX 1 /* buffer index of data in response */ 90 #define DATA_SLOT_2 2 /* used for ECDH private key */ 91 92 /* Definitions for the device lock state */ 93 #define DEVICE_LOCK_ADDR 0x15 94 #define LOCK_VALUE_IDX (RSP_DATA_IDX + 2) 95 #define LOCK_CONFIG_IDX (RSP_DATA_IDX + 3) 96 97 /* 98 * Wake High delay to data communication (microseconds). SDA should be stable 99 * high for this entire duration. 100 */ 101 #define TWHI_MIN 1500 102 #define TWHI_MAX 1550 103 104 /* Wake Low duration */ 105 #define TWLO_USEC 60 106 107 /* Command execution time (milliseconds) */ 108 #define MAX_EXEC_TIME_ECDH 58 109 #define MAX_EXEC_TIME_GENKEY 115 110 #define MAX_EXEC_TIME_READ 1 111 112 /* Command opcode */ 113 #define OPCODE_ECDH 0x43 114 #define OPCODE_GENKEY 0x40 115 #define OPCODE_READ 0x02 116 117 /* Definitions for the READ Command */ 118 #define READ_COUNT 7 119 120 /* Definitions for the GenKey Command */ 121 #define GENKEY_COUNT 7 122 #define GENKEY_MODE_PRIVATE 0x04 123 124 /* Definitions for the ECDH Command */ 125 #define ECDH_COUNT 71 126 #define ECDH_PREFIX_MODE 0x00 127 128 #endif /* __ATMEL_ECC_H__ */ 129
