LXR linux/drivers/net/ethernet/qualcomm/qca_7k

   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 QCAFRM_HEADER_LEN 8
  56
  57/* QCA7K footer len */
  58#define QCAFRM_FOOTER_LEN 2
  59
  60/* QCA7K Framing. */
  61#define QCAFRM_ERR_BASE -1000
  62
  63enum 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
 102struct 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
 115u16 qcafrm_create_header(u8 *buf, u16 len);
 116
 117u16 qcafrm_create_footer(u8 *buf);
 118
 119static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
 120{
 121        handle->init = QCAFRM_HW_LEN0;
 122        handle->state = handle->init;
 123}
 124
 125static 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
 142s32 qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_byte);
 143
 144#endif /* _QCA_FRAMING_H */
 145