1 | /* |
2 | * Copyright (c) 2011, 2012, Atheros Communications Inc. |
3 | * Copyright (c) 2014, I2SE GmbH |
4 | * |
5 | * Permission to use, copy, modify, and/or distribute this software |
6 | * for any purpose with or without fee is hereby granted, provided |
7 | * that the above copyright notice and this permission notice appear |
8 | * in all copies. |
9 | * |
10 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL |
11 | * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED |
12 | * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL |
13 | * THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR |
14 | * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM |
15 | * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, |
16 | * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
17 | * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
18 | */ |
19 | |
20 | /* Atheros Ethernet framing. Every Ethernet frame is surrounded by an atheros |
21 | * frame while transmitted over a serial channel. |
22 | */ |
23 | |
24 | #ifndef _QCA_FRAMING_H |
25 | #define _QCA_FRAMING_H |
26 | |
27 | #include <linux/if_ether.h> |
28 | #include <linux/if_vlan.h> |
29 | #include <linux/types.h> |
30 | |
31 | /* Frame is currently being received */ |
32 | #define QCAFRM_GATHER 0 |
33 | |
34 | /* No header byte while expecting it */ |
35 | #define QCAFRM_NOHEAD (QCAFRM_ERR_BASE - 1) |
36 | |
37 | /* No tailer byte while expecting it */ |
38 | #define QCAFRM_NOTAIL (QCAFRM_ERR_BASE - 2) |
39 | |
40 | /* Frame length is invalid */ |
41 | #define QCAFRM_INVLEN (QCAFRM_ERR_BASE - 3) |
42 | |
43 | /* Frame length is invalid */ |
44 | #define QCAFRM_INVFRAME (QCAFRM_ERR_BASE - 4) |
45 | |
46 | /* Min/Max Ethernet MTU: 46/1500 */ |
47 | #define QCAFRM_MIN_MTU (ETH_ZLEN - ETH_HLEN) |
48 | #define QCAFRM_MAX_MTU ETH_DATA_LEN |
49 | |
50 | /* Min/Max frame lengths */ |
51 | #define QCAFRM_MIN_LEN (QCAFRM_MIN_MTU + ETH_HLEN) |
52 | #define QCAFRM_MAX_LEN (QCAFRM_MAX_MTU + VLAN_ETH_HLEN) |
53 | |
54 | /* QCA7K header len */ |
55 | #define 8 |
56 | |
57 | /* QCA7K footer len */ |
58 | #define 2 |
59 | |
60 | /* QCA7K Framing. */ |
61 | #define QCAFRM_ERR_BASE -1000 |
62 | |
63 | enum qcafrm_state { |
64 | /* HW length is only available on SPI */ |
65 | QCAFRM_HW_LEN0 = 0x8000, |
66 | QCAFRM_HW_LEN1 = QCAFRM_HW_LEN0 - 1, |
67 | QCAFRM_HW_LEN2 = QCAFRM_HW_LEN1 - 1, |
68 | QCAFRM_HW_LEN3 = QCAFRM_HW_LEN2 - 1, |
69 | |
70 | /* Waiting first 0xAA of header */ |
71 | QCAFRM_WAIT_AA1 = QCAFRM_HW_LEN3 - 1, |
72 | |
73 | /* Waiting second 0xAA of header */ |
74 | QCAFRM_WAIT_AA2 = QCAFRM_WAIT_AA1 - 1, |
75 | |
76 | /* Waiting third 0xAA of header */ |
77 | QCAFRM_WAIT_AA3 = QCAFRM_WAIT_AA2 - 1, |
78 | |
79 | /* Waiting fourth 0xAA of header */ |
80 | QCAFRM_WAIT_AA4 = QCAFRM_WAIT_AA3 - 1, |
81 | |
82 | /* Waiting Byte 0-1 of length (litte endian) */ |
83 | QCAFRM_WAIT_LEN_BYTE0 = QCAFRM_WAIT_AA4 - 1, |
84 | QCAFRM_WAIT_LEN_BYTE1 = QCAFRM_WAIT_AA4 - 2, |
85 | |
86 | /* Reserved bytes */ |
87 | QCAFRM_WAIT_RSVD_BYTE1 = QCAFRM_WAIT_AA4 - 3, |
88 | QCAFRM_WAIT_RSVD_BYTE2 = QCAFRM_WAIT_AA4 - 4, |
89 | |
90 | /* The frame length is used as the state until |
91 | * the end of the Ethernet frame |
92 | * Waiting for first 0x55 of footer |
93 | */ |
94 | QCAFRM_WAIT_551 = 1, |
95 | |
96 | /* Waiting for second 0x55 of footer */ |
97 | QCAFRM_WAIT_552 = QCAFRM_WAIT_551 - 1 |
98 | }; |
99 | |
100 | /* Structure to maintain the frame decoding during reception. */ |
101 | |
102 | struct qcafrm_handle { |
103 | /* Current decoding state */ |
104 | enum qcafrm_state state; |
105 | /* Initial state depends on connection type */ |
106 | enum qcafrm_state init; |
107 | |
108 | /* Offset in buffer (borrowed for length too) */ |
109 | u16 offset; |
110 | |
111 | /* Frame length as kept by this module */ |
112 | u16 len; |
113 | }; |
114 | |
115 | u16 (u8 *buf, u16 len); |
116 | |
117 | u16 (u8 *buf); |
118 | |
119 | static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle) |
120 | { |
121 | handle->init = QCAFRM_HW_LEN0; |
122 | handle->state = handle->init; |
123 | } |
124 | |
125 | static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle) |
126 | { |
127 | handle->init = QCAFRM_WAIT_AA1; |
128 | handle->state = handle->init; |
129 | } |
130 | |
131 | /* Gather received bytes and try to extract a full Ethernet frame |
132 | * by following a simple state machine. |
133 | * |
134 | * Return: QCAFRM_GATHER No Ethernet frame fully received yet. |
135 | * QCAFRM_NOHEAD Header expected but not found. |
136 | * QCAFRM_INVLEN QCA7K frame length is invalid |
137 | * QCAFRM_NOTAIL Footer expected but not found. |
138 | * > 0 Number of byte in the fully received |
139 | * Ethernet frame |
140 | */ |
141 | |
142 | s32 qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_byte); |
143 | |
144 | #endif /* _QCA_FRAMING_H */ |
145 | |