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
50enum 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
89struct 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
99u16 qcafrm_create_header(u8 *buf, u16 len);
100
101u16 qcafrm_create_footer(u8 *buf);
102
103static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
104{
105 handle->init = QCAFRM_HW_LEN0;
106 handle->state = handle->init;
107}
108
109static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle)
110{
111 handle->init = QCAFRM_WAIT_AA1;
112 handle->state = handle->init;
113}
114
115s32 qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_byte);
116
117#endif /* _QCA_FRAMING_H */
118

source code of linux/drivers/net/ethernet/qualcomm/qca_7k_common.h