/* * Copyright (c) 2017, Microchip Technology Inc. * Author: Tudor Ambarus <tudor.ambarus@microchip.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program. If not, see <http://www.gnu.org/licenses/>. * */ #ifndef __ATMEL_ECC_H__ #define __ATMEL_ECC_H__ #define ATMEL_ECC_PRIORITY 300 #define COMMAND 0x03 /* packet function */ #define SLEEP_TOKEN 0x01 #define WAKE_TOKEN_MAX_SIZE 8 /* Definitions of Data and Command sizes */ #define WORD_ADDR_SIZE 1 #define COUNT_SIZE 1 #define CRC_SIZE 2 #define CMD_OVERHEAD_SIZE (COUNT_SIZE + CRC_SIZE) /* size in bytes of the n prime */ #define ATMEL_ECC_NIST_P256_N_SIZE 32 #define ATMEL_ECC_PUBKEY_SIZE (2 * ATMEL_ECC_NIST_P256_N_SIZE) #define STATUS_RSP_SIZE 4 #define ECDH_RSP_SIZE (32 + CMD_OVERHEAD_SIZE) #define GENKEY_RSP_SIZE (ATMEL_ECC_PUBKEY_SIZE + \ CMD_OVERHEAD_SIZE) #define READ_RSP_SIZE (4 + CMD_OVERHEAD_SIZE) #define MAX_RSP_SIZE GENKEY_RSP_SIZE /** * atmel_ecc_cmd - structure used for communicating with the device. * @word_addr: indicates the function of the packet sent to the device. This * byte should have a value of COMMAND for normal operation. * @count : number of bytes to be transferred to (or from) the device. * @opcode : the command code. * @param1 : the first parameter; always present. * @param2 : the second parameter; always present. * @data : optional remaining input data. Includes a 2-byte CRC. * @rxsize : size of the data received from i2c client. * @msecs : command execution time in milliseconds */ struct atmel_ecc_cmd { u8 word_addr; u8 count; u8 opcode; u8 param1; u16 param2; u8 data[MAX_RSP_SIZE]; u8 msecs; u16 rxsize; } __packed; /* Status/Error codes */ #define STATUS_SIZE 0x04 #define STATUS_NOERR 0x00 #define STATUS_WAKE_SUCCESSFUL 0x11 static const struct { u8 value; const char *error_text; } error_list[] = { { 0x01, "CheckMac or Verify miscompare" }, { 0x03, "Parse Error" }, { 0x05, "ECC Fault" }, { 0x0F, "Execution Error" }, { 0xEE, "Watchdog about to expire" }, { 0xFF, "CRC or other communication error" }, }; /* Definitions for eeprom organization */ #define CONFIG_ZONE 0 /* Definitions for Indexes common to all commands */ #define RSP_DATA_IDX 1 /* buffer index of data in response */ #define DATA_SLOT_2 2 /* used for ECDH private key */ /* Definitions for the device lock state */ #define DEVICE_LOCK_ADDR 0x15 #define LOCK_VALUE_IDX (RSP_DATA_IDX + 2) #define LOCK_CONFIG_IDX (RSP_DATA_IDX + 3) /* * Wake High delay to data communication (microseconds). SDA should be stable * high for this entire duration. */ #define TWHI_MIN 1500 #define TWHI_MAX 1550 /* Wake Low duration */ #define TWLO_USEC 60 /* Command execution time (milliseconds) */ #define MAX_EXEC_TIME_ECDH 58 #define MAX_EXEC_TIME_GENKEY 115 #define MAX_EXEC_TIME_READ 1 /* Command opcode */ #define OPCODE_ECDH 0x43 #define OPCODE_GENKEY 0x40 #define OPCODE_READ 0x02 /* Definitions for the READ Command */ #define READ_COUNT 7 /* Definitions for the GenKey Command */ #define GENKEY_COUNT 7 #define GENKEY_MODE_PRIVATE 0x04 /* Definitions for the ECDH Command */ #define ECDH_COUNT 71 #define ECDH_PREFIX_MODE 0x00 #endif /* __ATMEL_ECC_H__ */