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/*
* 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__ */
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