1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause */ 2 /* 3 * Copyright (c) 2011, 2012, Atheros Communications Inc. 4 * Copyright (c) 2014, I2SE GmbH 5 */ 6 7 /* Atheros Ethernet framing. Every Ethernet frame is surrounded by an atheros 8 * frame while transmitted over a serial channel. 9 */ 10 11 #ifndef _QCA_FRAMING_H 12 #define _QCA_FRAMING_H 13 14 #include <linux/if_ether.h> 15 #include <linux/if_vlan.h> 16 #include <linux/types.h> 17 18 /* Frame is currently being received */ 19 #define QCAFRM_GATHER 0 20 21 /* No header byte while expecting it */ 22 #define QCAFRM_NOHEAD (QCAFRM_ERR_BASE - 1) 23 24 /* No tailer byte while expecting it */ 25 #define QCAFRM_NOTAIL (QCAFRM_ERR_BASE - 2) 26 27 /* Frame length is invalid */ 28 #define QCAFRM_INVLEN (QCAFRM_ERR_BASE - 3) 29 30 /* Frame length is invalid */ 31 #define QCAFRM_INVFRAME (QCAFRM_ERR_BASE - 4) 32 33 /* Min/Max Ethernet MTU: 46/1500 */ 34 #define QCAFRM_MIN_MTU (ETH_ZLEN - ETH_HLEN) 35 #define QCAFRM_MAX_MTU ETH_DATA_LEN 36 37 /* Min/Max frame lengths */ 38 #define QCAFRM_MIN_LEN (QCAFRM_MIN_MTU + ETH_HLEN) 39 #define QCAFRM_MAX_LEN (QCAFRM_MAX_MTU + VLAN_ETH_HLEN) 40 41 /* QCA7K header len */ 42 #define QCAFRM_HEADER_LEN 8 43 44 /* QCA7K footer len */ 45 #define QCAFRM_FOOTER_LEN 2 46 47 /* QCA7K Framing. */ 48 #define QCAFRM_ERR_BASE -1000 49 50 enum qcafrm_state { 51 /* HW length is only available on SPI */ 52 QCAFRM_HW_LEN0 = 0x8000, 53 QCAFRM_HW_LEN1 = QCAFRM_HW_LEN0 - 1, 54 QCAFRM_HW_LEN2 = QCAFRM_HW_LEN1 - 1, 55 QCAFRM_HW_LEN3 = QCAFRM_HW_LEN2 - 1, 56 57 /* Waiting first 0xAA of header */ 58 QCAFRM_WAIT_AA1 = QCAFRM_HW_LEN3 - 1, 59 60 /* Waiting second 0xAA of header */ 61 QCAFRM_WAIT_AA2 = QCAFRM_WAIT_AA1 - 1, 62 63 /* Waiting third 0xAA of header */ 64 QCAFRM_WAIT_AA3 = QCAFRM_WAIT_AA2 - 1, 65 66 /* Waiting fourth 0xAA of header */ 67 QCAFRM_WAIT_AA4 = QCAFRM_WAIT_AA3 - 1, 68 69 /* Waiting Byte 0-1 of length (litte endian) */ 70 QCAFRM_WAIT_LEN_BYTE0 = QCAFRM_WAIT_AA4 - 1, 71 QCAFRM_WAIT_LEN_BYTE1 = QCAFRM_WAIT_AA4 - 2, 72 73 /* Reserved bytes */ 74 QCAFRM_WAIT_RSVD_BYTE1 = QCAFRM_WAIT_AA4 - 3, 75 QCAFRM_WAIT_RSVD_BYTE2 = QCAFRM_WAIT_AA4 - 4, 76 77 /* The frame length is used as the state until 78 * the end of the Ethernet frame 79 * Waiting for first 0x55 of footer 80 */ 81 QCAFRM_WAIT_551 = 1, 82 83 /* Waiting for second 0x55 of footer */ 84 QCAFRM_WAIT_552 = QCAFRM_WAIT_551 - 1 85 }; 86 87 /* Structure to maintain the frame decoding during reception. */ 88 89 struct qcafrm_handle { 90 /* Current decoding state */ 91 enum qcafrm_state state; 92 /* Initial state depends on connection type */ 93 enum qcafrm_state init; 94 95 /* Offset in buffer (borrowed for length too) */ 96 u16 offset; 97 }; 98 99 u16 qcafrm_create_header(u8 *buf, u16 len); 100 101 u16 qcafrm_create_footer(u8 *buf); 102 103 static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle) 104 { 105 handle->init = QCAFRM_HW_LEN0; 106 handle->state = handle->init; 107 } 108 109 static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle) 110 { 111 handle->init = QCAFRM_WAIT_AA1; 112 handle->state = handle->init; 113 } 114 115 s32 qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_byte); 116 117 #endif /* _QCA_FRAMING_H */ 118