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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | /* * Copyright (c) 2011, 2012, Atheros Communications Inc. * Copyright (c) 2014, I2SE GmbH * * Permission to use, copy, modify, and/or distribute this software * for any purpose with or without fee is hereby granted, provided * that the above copyright notice and this permission notice appear * in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL * THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* Atheros ethernet framing. Every Ethernet frame is surrounded * by an atheros frame while transmitted over a serial channel; */ #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include "qca_7k_common.h" u16 qcafrm_create_header(u8 *buf, u16 length) { __le16 len; if (!buf) return 0; len = cpu_to_le16(length); buf[0] = 0xAA; buf[1] = 0xAA; buf[2] = 0xAA; buf[3] = 0xAA; buf[4] = len & 0xff; buf[5] = (len >> 8) & 0xff; buf[6] = 0; buf[7] = 0; return QCAFRM_HEADER_LEN; } EXPORT_SYMBOL_GPL(qcafrm_create_header); u16 qcafrm_create_footer(u8 *buf) { if (!buf) return 0; buf[0] = 0x55; buf[1] = 0x55; return QCAFRM_FOOTER_LEN; } EXPORT_SYMBOL_GPL(qcafrm_create_footer); /* Gather received bytes and try to extract a full ethernet frame by * following a simple state machine. * * Return: QCAFRM_GATHER No ethernet frame fully received yet. * QCAFRM_NOHEAD Header expected but not found. * QCAFRM_INVLEN Atheros frame length is invalid * QCAFRM_NOTAIL Footer expected but not found. * > 0 Number of byte in the fully received * Ethernet frame */ s32 qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_byte) { s32 ret = QCAFRM_GATHER; u16 len; switch (handle->state) { case QCAFRM_HW_LEN0: case QCAFRM_HW_LEN1: /* by default, just go to next state */ handle->state--; if (recv_byte != 0x00) { /* first two bytes of length must be 0 */ handle->state = handle->init; } break; case QCAFRM_HW_LEN2: case QCAFRM_HW_LEN3: handle->state--; break; /* 4 bytes header pattern */ case QCAFRM_WAIT_AA1: case QCAFRM_WAIT_AA2: case QCAFRM_WAIT_AA3: case QCAFRM_WAIT_AA4: if (recv_byte != 0xAA) { ret = QCAFRM_NOHEAD; handle->state = handle->init; } else { handle->state--; } break; /* 2 bytes length. */ /* Borrow offset field to hold length for now. */ case QCAFRM_WAIT_LEN_BYTE0: handle->offset = recv_byte; handle->state = QCAFRM_WAIT_LEN_BYTE1; break; case QCAFRM_WAIT_LEN_BYTE1: handle->offset = handle->offset | (recv_byte << 8); handle->state = QCAFRM_WAIT_RSVD_BYTE1; break; case QCAFRM_WAIT_RSVD_BYTE1: handle->state = QCAFRM_WAIT_RSVD_BYTE2; break; case QCAFRM_WAIT_RSVD_BYTE2: len = handle->offset; if (len > buf_len || len < QCAFRM_MIN_LEN) { ret = QCAFRM_INVLEN; handle->state = handle->init; } else { handle->state = (enum qcafrm_state)(len + 1); /* Remaining number of bytes. */ handle->offset = 0; } break; default: /* Receiving Ethernet frame itself. */ buf[handle->offset] = recv_byte; handle->offset++; handle->state--; break; case QCAFRM_WAIT_551: if (recv_byte != 0x55) { ret = QCAFRM_NOTAIL; handle->state = handle->init; } else { handle->state = QCAFRM_WAIT_552; } break; case QCAFRM_WAIT_552: if (recv_byte != 0x55) { ret = QCAFRM_NOTAIL; handle->state = handle->init; } else { ret = handle->offset; /* Frame is fully received. */ handle->state = handle->init; } break; } return ret; } EXPORT_SYMBOL_GPL(qcafrm_fsm_decode); MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 common"); MODULE_AUTHOR("Qualcomm Atheros Communications"); MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>"); MODULE_LICENSE("Dual BSD/GPL"); |