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");
|
