linux/drivers/net/ethernet/qualcomm/qca_framing.h

135 lines
3.8 KiB
C

/*
* 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.
*/
#ifndef _QCA_FRAMING_H
#define _QCA_FRAMING_H
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/types.h>
/* Frame is currently being received */
#define QCAFRM_GATHER 0
/* No header byte while expecting it */
#define QCAFRM_NOHEAD (QCAFRM_ERR_BASE - 1)
/* No tailer byte while expecting it */
#define QCAFRM_NOTAIL (QCAFRM_ERR_BASE - 2)
/* Frame length is invalid */
#define QCAFRM_INVLEN (QCAFRM_ERR_BASE - 3)
/* Frame length is invalid */
#define QCAFRM_INVFRAME (QCAFRM_ERR_BASE - 4)
/* Min/Max Ethernet MTU */
#define QCAFRM_ETHMINMTU 46
#define QCAFRM_ETHMAXMTU 1500
/* Min/Max frame lengths */
#define QCAFRM_ETHMINLEN (QCAFRM_ETHMINMTU + ETH_HLEN)
#define QCAFRM_ETHMAXLEN (QCAFRM_ETHMAXMTU + VLAN_ETH_HLEN)
/* QCA7K header len */
#define QCAFRM_HEADER_LEN 8
/* QCA7K footer len */
#define QCAFRM_FOOTER_LEN 2
/* QCA7K Framing. */
#define QCAFRM_ERR_BASE -1000
enum qcafrm_state {
QCAFRM_HW_LEN0 = 0x8000,
QCAFRM_HW_LEN1 = QCAFRM_HW_LEN0 - 1,
QCAFRM_HW_LEN2 = QCAFRM_HW_LEN1 - 1,
QCAFRM_HW_LEN3 = QCAFRM_HW_LEN2 - 1,
/* Waiting first 0xAA of header */
QCAFRM_WAIT_AA1 = QCAFRM_HW_LEN3 - 1,
/* Waiting second 0xAA of header */
QCAFRM_WAIT_AA2 = QCAFRM_WAIT_AA1 - 1,
/* Waiting third 0xAA of header */
QCAFRM_WAIT_AA3 = QCAFRM_WAIT_AA2 - 1,
/* Waiting fourth 0xAA of header */
QCAFRM_WAIT_AA4 = QCAFRM_WAIT_AA3 - 1,
/* Waiting Byte 0-1 of length (litte endian) */
QCAFRM_WAIT_LEN_BYTE0 = QCAFRM_WAIT_AA4 - 1,
QCAFRM_WAIT_LEN_BYTE1 = QCAFRM_WAIT_AA4 - 2,
/* Reserved bytes */
QCAFRM_WAIT_RSVD_BYTE1 = QCAFRM_WAIT_AA4 - 3,
QCAFRM_WAIT_RSVD_BYTE2 = QCAFRM_WAIT_AA4 - 4,
/* The frame length is used as the state until
* the end of the Ethernet frame
* Waiting for first 0x55 of footer
*/
QCAFRM_WAIT_551 = 1,
/* Waiting for second 0x55 of footer */
QCAFRM_WAIT_552 = QCAFRM_WAIT_551 - 1
};
/* Structure to maintain the frame decoding during reception. */
struct qcafrm_handle {
/* Current decoding state */
enum qcafrm_state state;
/* Offset in buffer (borrowed for length too) */
s16 offset;
/* Frame length as kept by this module */
u16 len;
};
u16 qcafrm_create_header(u8 *buf, u16 len);
u16 qcafrm_create_footer(u8 *buf);
static inline void qcafrm_fsm_init(struct qcafrm_handle *handle)
{
handle->state = QCAFRM_HW_LEN0;
}
/* 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 QCA7K 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);
#endif /* _QCA_FRAMING_H */