LXR linux/drivers/crypto/atmel-ecc.h

   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 */
  57struct 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
  73static 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