drivers/crypto/atmel-ecc.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (c) 2017, Microchip Technology Inc.
   4  * Author: Tudor Ambarus <tudor.ambarus@microchip.com>
   5  */
   6
   7 #ifndef __ATMEL_ECC_H__
   8 #define __ATMEL_ECC_H__
   9
  10 #define ATMEL_ECC_PRIORITY              300
  11
  12 #define COMMAND                         0x03 /* packet function */
  13 #define SLEEP_TOKEN                     0x01
  14 #define WAKE_TOKEN_MAX_SIZE             8
  15
  16 /* Definitions of Data and Command sizes */
  17 #define WORD_ADDR_SIZE                  1
  18 #define COUNT_SIZE                      1
  19 #define CRC_SIZE                        2
  20 #define CMD_OVERHEAD_SIZE               (COUNT_SIZE + CRC_SIZE)
  21
  22 /* size in bytes of the n prime */
  23 #define ATMEL_ECC_NIST_P256_N_SIZE      32
  24 #define ATMEL_ECC_PUBKEY_SIZE           (2 * ATMEL_ECC_NIST_P256_N_SIZE)
  25
  26 #define STATUS_RSP_SIZE                 4
  27 #define ECDH_RSP_SIZE                   (32 + CMD_OVERHEAD_SIZE)
  28 #define GENKEY_RSP_SIZE                 (ATMEL_ECC_PUBKEY_SIZE + \
  29                                          CMD_OVERHEAD_SIZE)
  30 #define READ_RSP_SIZE                   (4 + CMD_OVERHEAD_SIZE)
  31 #define MAX_RSP_SIZE                    GENKEY_RSP_SIZE
  32
  33 /**
  34  * atmel_ecc_cmd - structure used for communicating with the device.
  35  * @word_addr: indicates the function of the packet sent to the device. This
  36  *             byte should have a value of COMMAND for normal operation.
  37  * @count    : number of bytes to be transferred to (or from) the device.
  38  * @opcode   : the command code.
  39  * @param1   : the first parameter; always present.
  40  * @param2   : the second parameter; always present.
  41  * @data     : optional remaining input data. Includes a 2-byte CRC.
  42  * @rxsize   : size of the data received from i2c client.
  43  * @msecs    : command execution time in milliseconds
  44  */
  45 struct atmel_ecc_cmd {
  46         u8 word_addr;
  47         u8 count;
  48         u8 opcode;
  49         u8 param1;
  50         u16 param2;
  51         u8 data[MAX_RSP_SIZE];
  52         u8 msecs;
  53         u16 rxsize;
  54 } __packed;
  55
  56 /* Status/Error codes */
  57 #define STATUS_SIZE                     0x04
  58 #define STATUS_NOERR                    0x00
  59 #define STATUS_WAKE_SUCCESSFUL          0x11
  60
  61 static const struct {
  62         u8 value;
  63         const char *error_text;
  64 } error_list[] = {
  65         { 0x01, "CheckMac or Verify miscompare" },
  66         { 0x03, "Parse Error" },
  67         { 0x05, "ECC Fault" },
  68         { 0x0F, "Execution Error" },
  69         { 0xEE, "Watchdog about to expire" },
  70         { 0xFF, "CRC or other communication error" },
  71 };
  72
  73 /* Definitions for eeprom organization */
  74 #define CONFIG_ZONE                     0
  75
  76 /* Definitions for Indexes common to all commands */
  77 #define RSP_DATA_IDX                    1 /* buffer index of data in response */
  78 #define DATA_SLOT_2                     2 /* used for ECDH private key */
  79
  80 /* Definitions for the device lock state */
  81 #define DEVICE_LOCK_ADDR                0x15
  82 #define LOCK_VALUE_IDX                  (RSP_DATA_IDX + 2)
  83 #define LOCK_CONFIG_IDX                 (RSP_DATA_IDX + 3)
  84
  85 /*
  86  * Wake High delay to data communication (microseconds). SDA should be stable
  87  * high for this entire duration.
  88  */
  89 #define TWHI_MIN                        1500
  90 #define TWHI_MAX                        1550
  91
  92 /* Wake Low duration */
  93 #define TWLO_USEC                       60
  94
  95 /* Command execution time (milliseconds) */
  96 #define MAX_EXEC_TIME_ECDH              58
  97 #define MAX_EXEC_TIME_GENKEY            115
  98 #define MAX_EXEC_TIME_READ              1
  99
 100 /* Command opcode */
 101 #define OPCODE_ECDH                     0x43
 102 #define OPCODE_GENKEY                   0x40
 103 #define OPCODE_READ                     0x02
 104
 105 /* Definitions for the READ Command */
 106 #define READ_COUNT                      7
 107
 108 /* Definitions for the GenKey Command */
 109 #define GENKEY_COUNT                    7
 110 #define GENKEY_MODE_PRIVATE             0x04
 111
 112 /* Definitions for the ECDH Command */
 113 #define ECDH_COUNT                      71
 114 #define ECDH_PREFIX_MODE                0x00
 115
 116 #endif /* __ATMEL_ECC_H__ */