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    Subject[PATCH 01/13] ISDN: Make isdnhdlc usable for other ISDN drivers
    From
    isdnhdlc is useful for other ISDN drivers as well.
    Move the include file to a central location and the source
    to the central isdn location.

    Signed-off-by: Karsten Keil <keil@b1-systems.de>
    ---
    drivers/isdn/Kconfig | 6 +-
    drivers/isdn/hisax/Kconfig | 6 +-
    drivers/isdn/hisax/Makefile | 4 -
    drivers/isdn/hisax/isdnhdlc.c | 603 -----------------------------------------
    drivers/isdn/hisax/isdnhdlc.h | 70 -----
    drivers/isdn/hisax/st5481.h | 2 +-
    drivers/isdn/i4l/Kconfig | 11 +
    drivers/isdn/i4l/Makefile | 1 +
    drivers/isdn/i4l/isdnhdlc.c | 603 +++++++++++++++++++++++++++++++++++++++++
    include/linux/isdn/hdlc.h | 70 +++++
    10 files changed, 689 insertions(+), 687 deletions(-)
    delete mode 100644 drivers/isdn/hisax/isdnhdlc.c
    delete mode 100644 drivers/isdn/hisax/isdnhdlc.h
    create mode 100644 drivers/isdn/i4l/isdnhdlc.c
    create mode 100644 include/linux/isdn/hdlc.h

    diff --git a/drivers/isdn/Kconfig b/drivers/isdn/Kconfig
    index 02bdca6..022a194 100644
    --- a/drivers/isdn/Kconfig
    +++ b/drivers/isdn/Kconfig
    @@ -21,8 +21,6 @@ menuconfig ISDN

    if ISDN

    -source "drivers/isdn/mISDN/Kconfig"
    -
    menuconfig ISDN_I4L
    tristate "Old ISDN4Linux (deprecated)"
    ---help---
    @@ -41,9 +39,9 @@ menuconfig ISDN_I4L
    It is still available, though, for use with adapters that are not
    supported by the new CAPI subsystem yet.

    -if ISDN_I4L
    +source "drivers/isdn/mISDN/Kconfig"
    +
    source "drivers/isdn/i4l/Kconfig"
    -endif

    menuconfig ISDN_CAPI
    tristate "CAPI 2.0 subsystem"
    diff --git a/drivers/isdn/hisax/Kconfig b/drivers/isdn/hisax/Kconfig
    index 7832d8b..3464ebc 100644
    --- a/drivers/isdn/hisax/Kconfig
    +++ b/drivers/isdn/hisax/Kconfig
    @@ -391,6 +391,7 @@ comment "HiSax sub driver modules"
    config HISAX_ST5481
    tristate "ST5481 USB ISDN modem (EXPERIMENTAL)"
    depends on USB && EXPERIMENTAL
    + select ISDN_HDLC
    select CRC_CCITT
    select BITREVERSE
    help
    @@ -418,11 +419,6 @@ config HISAX_FRITZ_PCIPNP
    (the latter also needs you to select "ISA Plug and Play support"
    from the menu "Plug and Play configuration")

    -config HISAX_HDLC
    - bool
    - depends on HISAX_ST5481
    - default y
    -
    config HISAX_AVM_A1_PCMCIA
    bool
    depends on HISAX_AVM_A1_CS
    diff --git a/drivers/isdn/hisax/Makefile b/drivers/isdn/hisax/Makefile
    index c7a3794..ab638b0 100644
    --- a/drivers/isdn/hisax/Makefile
    +++ b/drivers/isdn/hisax/Makefile
    @@ -16,10 +16,6 @@ obj-$(CONFIG_HISAX_HFCUSB) += hfc_usb.o
    obj-$(CONFIG_HISAX_HFC4S8S) += hfc4s8s_l1.o
    obj-$(CONFIG_HISAX_FRITZ_PCIPNP) += hisax_isac.o hisax_fcpcipnp.o

    -ifdef CONFIG_HISAX_HDLC
    -obj-$(CONFIG_ISDN_DRV_HISAX) += isdnhdlc.o
    -endif
    -
    # Multipart objects.

    hisax_st5481-y := st5481_init.o st5481_usb.o st5481_d.o \
    diff --git a/drivers/isdn/hisax/isdnhdlc.c b/drivers/isdn/hisax/isdnhdlc.c
    deleted file mode 100644
    index c69a77a..0000000
    --- a/drivers/isdn/hisax/isdnhdlc.c
    +++ /dev/null
    @@ -1,603 +0,0 @@
    -/*
    - * isdnhdlc.c -- General purpose ISDN HDLC decoder.
    - *
    - *Copyright (C) 2002 Wolfgang Mües <wolfgang@iksw-muees.de>
    - * 2001 Frode Isaksen <fisaksen@bewan.com>
    - * 2001 Kai Germaschewski <kai.germaschewski@gmx.de>
    - *
    - * This program is free software; you can redistribute it and/or modify
    - * it under the terms of the GNU General Public License as published by
    - * the Free Software Foundation; either version 2 of the License, or
    - * (at your option) any later version.
    - *
    - * This program is distributed in the hope that it will be useful,
    - * but WITHOUT ANY WARRANTY; without even the implied warranty of
    - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    - * GNU General Public License for more details.
    - *
    - * You should have received a copy of the GNU General Public License
    - * along with this program; if not, write to the Free Software
    - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    - */
    -
    -#include <linux/module.h>
    -#include <linux/init.h>
    -#include <linux/crc-ccitt.h>
    -#include "isdnhdlc.h"
    -
    -/*-------------------------------------------------------------------*/
    -
    -MODULE_AUTHOR("Wolfgang Mües <wolfgang@iksw-muees.de>, "
    - "Frode Isaksen <fisaksen@bewan.com>, "
    - "Kai Germaschewski <kai.germaschewski@gmx.de>");
    -MODULE_DESCRIPTION("General purpose ISDN HDLC decoder");
    -MODULE_LICENSE("GPL");
    -
    -/*-------------------------------------------------------------------*/
    -
    -enum {
    - HDLC_FAST_IDLE,HDLC_GET_FLAG_B0,HDLC_GETFLAG_B1A6,HDLC_GETFLAG_B7,
    - HDLC_GET_DATA,HDLC_FAST_FLAG
    -};
    -
    -enum {
    - HDLC_SEND_DATA,HDLC_SEND_CRC1,HDLC_SEND_FAST_FLAG,
    - HDLC_SEND_FIRST_FLAG,HDLC_SEND_CRC2,HDLC_SEND_CLOSING_FLAG,
    - HDLC_SEND_IDLE1,HDLC_SEND_FAST_IDLE,HDLC_SENDFLAG_B0,
    - HDLC_SENDFLAG_B1A6,HDLC_SENDFLAG_B7,STOPPED
    -};
    -
    -void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56)
    -{
    - hdlc->bit_shift = 0;
    - hdlc->hdlc_bits1 = 0;
    - hdlc->data_bits = 0;
    - hdlc->ffbit_shift = 0;
    - hdlc->data_received = 0;
    - hdlc->state = HDLC_GET_DATA;
    - hdlc->do_adapt56 = do_adapt56;
    - hdlc->dchannel = 0;
    - hdlc->crc = 0;
    - hdlc->cbin = 0;
    - hdlc->shift_reg = 0;
    - hdlc->ffvalue = 0;
    - hdlc->dstpos = 0;
    -}
    -
    -void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc, int is_d_channel, int do_adapt56)
    -{
    - hdlc->bit_shift = 0;
    - hdlc->hdlc_bits1 = 0;
    - hdlc->data_bits = 0;
    - hdlc->ffbit_shift = 0;
    - hdlc->data_received = 0;
    - hdlc->do_closing = 0;
    - hdlc->ffvalue = 0;
    - if (is_d_channel) {
    - hdlc->dchannel = 1;
    - hdlc->state = HDLC_SEND_FIRST_FLAG;
    - } else {
    - hdlc->dchannel = 0;
    - hdlc->state = HDLC_SEND_FAST_FLAG;
    - hdlc->ffvalue = 0x7e;
    - }
    - hdlc->cbin = 0x7e;
    - hdlc->bit_shift = 0;
    - if(do_adapt56){
    - hdlc->do_adapt56 = 1;
    - hdlc->data_bits = 0;
    - hdlc->state = HDLC_SENDFLAG_B0;
    - } else {
    - hdlc->do_adapt56 = 0;
    - hdlc->data_bits = 8;
    - }
    - hdlc->shift_reg = 0;
    -}
    -
    -/*
    - isdnhdlc_decode - decodes HDLC frames from a transparent bit stream.
    -
    - The source buffer is scanned for valid HDLC frames looking for
    - flags (01111110) to indicate the start of a frame. If the start of
    - the frame is found, the bit stuffing is removed (0 after 5 1's).
    - When a new flag is found, the complete frame has been received
    - and the CRC is checked.
    - If a valid frame is found, the function returns the frame length
    - excluding the CRC with the bit HDLC_END_OF_FRAME set.
    - If the beginning of a valid frame is found, the function returns
    - the length.
    - If a framing error is found (too many 1s and not a flag) the function
    - returns the length with the bit HDLC_FRAMING_ERROR set.
    - If a CRC error is found the function returns the length with the
    - bit HDLC_CRC_ERROR set.
    - If the frame length exceeds the destination buffer size, the function
    - returns the length with the bit HDLC_LENGTH_ERROR set.
    -
    - src - source buffer
    - slen - source buffer length
    - count - number of bytes removed (decoded) from the source buffer
    - dst _ destination buffer
    - dsize - destination buffer size
    - returns - number of decoded bytes in the destination buffer and status
    - flag.
    - */
    -int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src,
    - int slen, int *count, unsigned char *dst, int dsize)
    -{
    - int status=0;
    -
    - static const unsigned char fast_flag[]={
    - 0x00,0x00,0x00,0x20,0x30,0x38,0x3c,0x3e,0x3f
    - };
    -
    - static const unsigned char fast_flag_value[]={
    - 0x00,0x7e,0xfc,0xf9,0xf3,0xe7,0xcf,0x9f,0x3f
    - };
    -
    - static const unsigned char fast_abort[]={
    - 0x00,0x00,0x80,0xc0,0xe0,0xf0,0xf8,0xfc,0xfe,0xff
    - };
    -
    - *count = slen;
    -
    - while(slen > 0){
    - if(hdlc->bit_shift==0){
    - hdlc->cbin = *src++;
    - slen--;
    - hdlc->bit_shift = 8;
    - if(hdlc->do_adapt56){
    - hdlc->bit_shift --;
    - }
    - }
    -
    - switch(hdlc->state){
    - case STOPPED:
    - return 0;
    - case HDLC_FAST_IDLE:
    - if(hdlc->cbin == 0xff){
    - hdlc->bit_shift = 0;
    - break;
    - }
    - hdlc->state = HDLC_GET_FLAG_B0;
    - hdlc->hdlc_bits1 = 0;
    - hdlc->bit_shift = 8;
    - break;
    - case HDLC_GET_FLAG_B0:
    - if(!(hdlc->cbin & 0x80)) {
    - hdlc->state = HDLC_GETFLAG_B1A6;
    - hdlc->hdlc_bits1 = 0;
    - } else {
    - if(!hdlc->do_adapt56){
    - if(++hdlc->hdlc_bits1 >=8 ) if(hdlc->bit_shift==1)
    - hdlc->state = HDLC_FAST_IDLE;
    - }
    - }
    - hdlc->cbin<<=1;
    - hdlc->bit_shift --;
    - break;
    - case HDLC_GETFLAG_B1A6:
    - if(hdlc->cbin & 0x80){
    - hdlc->hdlc_bits1++;
    - if(hdlc->hdlc_bits1==6){
    - hdlc->state = HDLC_GETFLAG_B7;
    - }
    - } else {
    - hdlc->hdlc_bits1 = 0;
    - }
    - hdlc->cbin<<=1;
    - hdlc->bit_shift --;
    - break;
    - case HDLC_GETFLAG_B7:
    - if(hdlc->cbin & 0x80) {
    - hdlc->state = HDLC_GET_FLAG_B0;
    - } else {
    - hdlc->state = HDLC_GET_DATA;
    - hdlc->crc = 0xffff;
    - hdlc->shift_reg = 0;
    - hdlc->hdlc_bits1 = 0;
    - hdlc->data_bits = 0;
    - hdlc->data_received = 0;
    - }
    - hdlc->cbin<<=1;
    - hdlc->bit_shift --;
    - break;
    - case HDLC_GET_DATA:
    - if(hdlc->cbin & 0x80){
    - hdlc->hdlc_bits1++;
    - switch(hdlc->hdlc_bits1){
    - case 6:
    - break;
    - case 7:
    - if(hdlc->data_received) {
    - // bad frame
    - status = -HDLC_FRAMING_ERROR;
    - }
    - if(!hdlc->do_adapt56){
    - if(hdlc->cbin==fast_abort[hdlc->bit_shift+1]){
    - hdlc->state = HDLC_FAST_IDLE;
    - hdlc->bit_shift=1;
    - break;
    - }
    - } else {
    - hdlc->state = HDLC_GET_FLAG_B0;
    - }
    - break;
    - default:
    - hdlc->shift_reg>>=1;
    - hdlc->shift_reg |= 0x80;
    - hdlc->data_bits++;
    - break;
    - }
    - } else {
    - switch(hdlc->hdlc_bits1){
    - case 5:
    - break;
    - case 6:
    - if(hdlc->data_received){
    - if (hdlc->dstpos < 2) {
    - status = -HDLC_FRAMING_ERROR;
    - } else if (hdlc->crc != 0xf0b8){
    - // crc error
    - status = -HDLC_CRC_ERROR;
    - } else {
    - // remove CRC
    - hdlc->dstpos -= 2;
    - // good frame
    - status = hdlc->dstpos;
    - }
    - }
    - hdlc->crc = 0xffff;
    - hdlc->shift_reg = 0;
    - hdlc->data_bits = 0;
    - if(!hdlc->do_adapt56){
    - if(hdlc->cbin==fast_flag[hdlc->bit_shift]){
    - hdlc->ffvalue = fast_flag_value[hdlc->bit_shift];
    - hdlc->state = HDLC_FAST_FLAG;
    - hdlc->ffbit_shift = hdlc->bit_shift;
    - hdlc->bit_shift = 1;
    - } else {
    - hdlc->state = HDLC_GET_DATA;
    - hdlc->data_received = 0;
    - }
    - } else {
    - hdlc->state = HDLC_GET_DATA;
    - hdlc->data_received = 0;
    - }
    - break;
    - default:
    - hdlc->shift_reg>>=1;
    - hdlc->data_bits++;
    - break;
    - }
    - hdlc->hdlc_bits1 = 0;
    - }
    - if (status) {
    - hdlc->dstpos = 0;
    - *count -= slen;
    - hdlc->cbin <<= 1;
    - hdlc->bit_shift--;
    - return status;
    - }
    - if(hdlc->data_bits==8){
    - hdlc->data_bits = 0;
    - hdlc->data_received = 1;
    - hdlc->crc = crc_ccitt_byte(hdlc->crc, hdlc->shift_reg);
    -
    - // good byte received
    - if (hdlc->dstpos < dsize) {
    - dst[hdlc->dstpos++] = hdlc->shift_reg;
    - } else {
    - // frame too long
    - status = -HDLC_LENGTH_ERROR;
    - hdlc->dstpos = 0;
    - }
    - }
    - hdlc->cbin <<= 1;
    - hdlc->bit_shift--;
    - break;
    - case HDLC_FAST_FLAG:
    - if(hdlc->cbin==hdlc->ffvalue){
    - hdlc->bit_shift = 0;
    - break;
    - } else {
    - if(hdlc->cbin == 0xff){
    - hdlc->state = HDLC_FAST_IDLE;
    - hdlc->bit_shift=0;
    - } else if(hdlc->ffbit_shift==8){
    - hdlc->state = HDLC_GETFLAG_B7;
    - break;
    - } else {
    - hdlc->shift_reg = fast_abort[hdlc->ffbit_shift-1];
    - hdlc->hdlc_bits1 = hdlc->ffbit_shift-2;
    - if(hdlc->hdlc_bits1<0)hdlc->hdlc_bits1 = 0;
    - hdlc->data_bits = hdlc->ffbit_shift-1;
    - hdlc->state = HDLC_GET_DATA;
    - hdlc->data_received = 0;
    - }
    - }
    - break;
    - default:
    - break;
    - }
    - }
    - *count -= slen;
    - return 0;
    -}
    -
    -/*
    - isdnhdlc_encode - encodes HDLC frames to a transparent bit stream.
    -
    - The bit stream starts with a beginning flag (01111110). After
    - that each byte is added to the bit stream with bit stuffing added
    - (0 after 5 1's).
    - When the last byte has been removed from the source buffer, the
    - CRC (2 bytes is added) and the frame terminates with the ending flag.
    - For the dchannel, the idle character (all 1's) is also added at the end.
    - If this function is called with empty source buffer (slen=0), flags or
    - idle character will be generated.
    -
    - src - source buffer
    - slen - source buffer length
    - count - number of bytes removed (encoded) from source buffer
    - dst _ destination buffer
    - dsize - destination buffer size
    - returns - number of encoded bytes in the destination buffer
    -*/
    -int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const unsigned char *src,
    - unsigned short slen, int *count,
    - unsigned char *dst, int dsize)
    -{
    - static const unsigned char xfast_flag_value[] = {
    - 0x7e,0x3f,0x9f,0xcf,0xe7,0xf3,0xf9,0xfc,0x7e
    - };
    -
    - int len = 0;
    -
    - *count = slen;
    -
    - while (dsize > 0) {
    - if(hdlc->bit_shift==0){
    - if(slen && !hdlc->do_closing){
    - hdlc->shift_reg = *src++;
    - slen--;
    - if (slen == 0)
    - hdlc->do_closing = 1; /* closing sequence, CRC + flag(s) */
    - hdlc->bit_shift = 8;
    - } else {
    - if(hdlc->state == HDLC_SEND_DATA){
    - if(hdlc->data_received){
    - hdlc->state = HDLC_SEND_CRC1;
    - hdlc->crc ^= 0xffff;
    - hdlc->bit_shift = 8;
    - hdlc->shift_reg = hdlc->crc & 0xff;
    - } else if(!hdlc->do_adapt56){
    - hdlc->state = HDLC_SEND_FAST_FLAG;
    - } else {
    - hdlc->state = HDLC_SENDFLAG_B0;
    - }
    - }
    -
    - }
    - }
    -
    - switch(hdlc->state){
    - case STOPPED:
    - while (dsize--)
    - *dst++ = 0xff;
    -
    - return dsize;
    - case HDLC_SEND_FAST_FLAG:
    - hdlc->do_closing = 0;
    - if(slen == 0){
    - *dst++ = hdlc->ffvalue;
    - len++;
    - dsize--;
    - break;
    - }
    - if(hdlc->bit_shift==8){
    - hdlc->cbin = hdlc->ffvalue>>(8-hdlc->data_bits);
    - hdlc->state = HDLC_SEND_DATA;
    - hdlc->crc = 0xffff;
    - hdlc->hdlc_bits1 = 0;
    - hdlc->data_received = 1;
    - }
    - break;
    - case HDLC_SENDFLAG_B0:
    - hdlc->do_closing = 0;
    - hdlc->cbin <<= 1;
    - hdlc->data_bits++;
    - hdlc->hdlc_bits1 = 0;
    - hdlc->state = HDLC_SENDFLAG_B1A6;
    - break;
    - case HDLC_SENDFLAG_B1A6:
    - hdlc->cbin <<= 1;
    - hdlc->data_bits++;
    - hdlc->cbin++;
    - if(++hdlc->hdlc_bits1 == 6)
    - hdlc->state = HDLC_SENDFLAG_B7;
    - break;
    - case HDLC_SENDFLAG_B7:
    - hdlc->cbin <<= 1;
    - hdlc->data_bits++;
    - if(slen == 0){
    - hdlc->state = HDLC_SENDFLAG_B0;
    - break;
    - }
    - if(hdlc->bit_shift==8){
    - hdlc->state = HDLC_SEND_DATA;
    - hdlc->crc = 0xffff;
    - hdlc->hdlc_bits1 = 0;
    - hdlc->data_received = 1;
    - }
    - break;
    - case HDLC_SEND_FIRST_FLAG:
    - hdlc->data_received = 1;
    - if(hdlc->data_bits==8){
    - hdlc->state = HDLC_SEND_DATA;
    - hdlc->crc = 0xffff;
    - hdlc->hdlc_bits1 = 0;
    - break;
    - }
    - hdlc->cbin <<= 1;
    - hdlc->data_bits++;
    - if(hdlc->shift_reg & 0x01)
    - hdlc->cbin++;
    - hdlc->shift_reg >>= 1;
    - hdlc->bit_shift--;
    - if(hdlc->bit_shift==0){
    - hdlc->state = HDLC_SEND_DATA;
    - hdlc->crc = 0xffff;
    - hdlc->hdlc_bits1 = 0;
    - }
    - break;
    - case HDLC_SEND_DATA:
    - hdlc->cbin <<= 1;
    - hdlc->data_bits++;
    - if(hdlc->hdlc_bits1 == 5){
    - hdlc->hdlc_bits1 = 0;
    - break;
    - }
    - if(hdlc->bit_shift==8){
    - hdlc->crc = crc_ccitt_byte(hdlc->crc, hdlc->shift_reg);
    - }
    - if(hdlc->shift_reg & 0x01){
    - hdlc->hdlc_bits1++;
    - hdlc->cbin++;
    - hdlc->shift_reg >>= 1;
    - hdlc->bit_shift--;
    - } else {
    - hdlc->hdlc_bits1 = 0;
    - hdlc->shift_reg >>= 1;
    - hdlc->bit_shift--;
    - }
    - break;
    - case HDLC_SEND_CRC1:
    - hdlc->cbin <<= 1;
    - hdlc->data_bits++;
    - if(hdlc->hdlc_bits1 == 5){
    - hdlc->hdlc_bits1 = 0;
    - break;
    - }
    - if(hdlc->shift_reg & 0x01){
    - hdlc->hdlc_bits1++;
    - hdlc->cbin++;
    - hdlc->shift_reg >>= 1;
    - hdlc->bit_shift--;
    - } else {
    - hdlc->hdlc_bits1 = 0;
    - hdlc->shift_reg >>= 1;
    - hdlc->bit_shift--;
    - }
    - if(hdlc->bit_shift==0){
    - hdlc->shift_reg = (hdlc->crc >> 8);
    - hdlc->state = HDLC_SEND_CRC2;
    - hdlc->bit_shift = 8;
    - }
    - break;
    - case HDLC_SEND_CRC2:
    - hdlc->cbin <<= 1;
    - hdlc->data_bits++;
    - if(hdlc->hdlc_bits1 == 5){
    - hdlc->hdlc_bits1 = 0;
    - break;
    - }
    - if(hdlc->shift_reg & 0x01){
    - hdlc->hdlc_bits1++;
    - hdlc->cbin++;
    - hdlc->shift_reg >>= 1;
    - hdlc->bit_shift--;
    - } else {
    - hdlc->hdlc_bits1 = 0;
    - hdlc->shift_reg >>= 1;
    - hdlc->bit_shift--;
    - }
    - if(hdlc->bit_shift==0){
    - hdlc->shift_reg = 0x7e;
    - hdlc->state = HDLC_SEND_CLOSING_FLAG;
    - hdlc->bit_shift = 8;
    - }
    - break;
    - case HDLC_SEND_CLOSING_FLAG:
    - hdlc->cbin <<= 1;
    - hdlc->data_bits++;
    - if(hdlc->hdlc_bits1 == 5){
    - hdlc->hdlc_bits1 = 0;
    - break;
    - }
    - if(hdlc->shift_reg & 0x01){
    - hdlc->cbin++;
    - }
    - hdlc->shift_reg >>= 1;
    - hdlc->bit_shift--;
    - if(hdlc->bit_shift==0){
    - hdlc->ffvalue = xfast_flag_value[hdlc->data_bits];
    - if(hdlc->dchannel){
    - hdlc->ffvalue = 0x7e;
    - hdlc->state = HDLC_SEND_IDLE1;
    - hdlc->bit_shift = 8-hdlc->data_bits;
    - if(hdlc->bit_shift==0)
    - hdlc->state = HDLC_SEND_FAST_IDLE;
    - } else {
    - if(!hdlc->do_adapt56){
    - hdlc->state = HDLC_SEND_FAST_FLAG;
    - hdlc->data_received = 0;
    - } else {
    - hdlc->state = HDLC_SENDFLAG_B0;
    - hdlc->data_received = 0;
    - }
    - // Finished with this frame, send flags
    - if (dsize > 1) dsize = 1;
    - }
    - }
    - break;
    - case HDLC_SEND_IDLE1:
    - hdlc->do_closing = 0;
    - hdlc->cbin <<= 1;
    - hdlc->cbin++;
    - hdlc->data_bits++;
    - hdlc->bit_shift--;
    - if(hdlc->bit_shift==0){
    - hdlc->state = HDLC_SEND_FAST_IDLE;
    - hdlc->bit_shift = 0;
    - }
    - break;
    - case HDLC_SEND_FAST_IDLE:
    - hdlc->do_closing = 0;
    - hdlc->cbin = 0xff;
    - hdlc->data_bits = 8;
    - if(hdlc->bit_shift == 8){
    - hdlc->cbin = 0x7e;
    - hdlc->state = HDLC_SEND_FIRST_FLAG;
    - } else {
    - *dst++ = hdlc->cbin;
    - hdlc->bit_shift = hdlc->data_bits = 0;
    - len++;
    - dsize = 0;
    - }
    - break;
    - default:
    - break;
    - }
    - if(hdlc->do_adapt56){
    - if(hdlc->data_bits==7){
    - hdlc->cbin <<= 1;
    - hdlc->cbin++;
    - hdlc->data_bits++;
    - }
    - }
    - if(hdlc->data_bits==8){
    - *dst++ = hdlc->cbin;
    - hdlc->data_bits = 0;
    - len++;
    - dsize--;
    - }
    - }
    - *count -= slen;
    -
    - return len;
    -}
    -
    -EXPORT_SYMBOL(isdnhdlc_rcv_init);
    -EXPORT_SYMBOL(isdnhdlc_decode);
    -EXPORT_SYMBOL(isdnhdlc_out_init);
    -EXPORT_SYMBOL(isdnhdlc_encode);
    diff --git a/drivers/isdn/hisax/isdnhdlc.h b/drivers/isdn/hisax/isdnhdlc.h
    deleted file mode 100644
    index cf0a95a..0000000
    --- a/drivers/isdn/hisax/isdnhdlc.h
    +++ /dev/null
    @@ -1,70 +0,0 @@
    -/*
    - * isdnhdlc.h -- General purpose ISDN HDLC decoder.
    - *
    - * Implementation of a HDLC decoder/encoder in software.
    - * Neccessary because some ISDN devices don't have HDLC
    - * controllers. Also included: a bit reversal table.
    - *
    - *Copyright (C) 2002 Wolfgang Mües <wolfgang@iksw-muees.de>
    - * 2001 Frode Isaksen <fisaksen@bewan.com>
    - * 2001 Kai Germaschewski <kai.germaschewski@gmx.de>
    - *
    - * This program is free software; you can redistribute it and/or modify
    - * it under the terms of the GNU General Public License as published by
    - * the Free Software Foundation; either version 2 of the License, or
    - * (at your option) any later version.
    - *
    - * This program is distributed in the hope that it will be useful,
    - * but WITHOUT ANY WARRANTY; without even the implied warranty of
    - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    - * GNU General Public License for more details.
    - *
    - * You should have received a copy of the GNU General Public License
    - * along with this program; if not, write to the Free Software
    - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    - */
    -
    -#ifndef __ISDNHDLC_H__
    -#define __ISDNHDLC_H__
    -
    -struct isdnhdlc_vars {
    - int bit_shift;
    - int hdlc_bits1;
    - int data_bits;
    - int ffbit_shift; // encoding only
    - int state;
    - int dstpos;
    -
    - unsigned short crc;
    -
    - unsigned char cbin;
    - unsigned char shift_reg;
    - unsigned char ffvalue;
    -
    - unsigned int data_received:1; // set if transferring data
    - unsigned int dchannel:1; // set if D channel (send idle instead of flags)
    - unsigned int do_adapt56:1; // set if 56K adaptation
    - unsigned int do_closing:1; // set if in closing phase (need to send CRC + flag
    -};
    -
    -
    -/*
    - The return value from isdnhdlc_decode is
    - the frame length, 0 if no complete frame was decoded,
    - or a negative error number
    -*/
    -#define HDLC_FRAMING_ERROR 1
    -#define HDLC_CRC_ERROR 2
    -#define HDLC_LENGTH_ERROR 3
    -
    -extern void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56);
    -
    -extern int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src, int slen,int *count,
    - unsigned char *dst, int dsize);
    -
    -extern void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc,int is_d_channel,int do_adapt56);
    -
    -extern int isdnhdlc_encode (struct isdnhdlc_vars *hdlc,const unsigned char *src,unsigned short slen,int *count,
    - unsigned char *dst,int dsize);
    -
    -#endif /* __ISDNHDLC_H__ */
    diff --git a/drivers/isdn/hisax/st5481.h b/drivers/isdn/hisax/st5481.h
    index cff7a63..64f78a8 100644
    --- a/drivers/isdn/hisax/st5481.h
    +++ b/drivers/isdn/hisax/st5481.h
    @@ -226,7 +226,7 @@ printk(KERN_WARNING "%s:%s: " format "\n" , __FILE__, __func__ , ## arg)
    #define INFO(format, arg...) \
    printk(KERN_INFO "%s:%s: " format "\n" , __FILE__, __func__ , ## arg)

    -#include "isdnhdlc.h"
    +#include <linux/isdn/hdlc.h>
    #include "fsm.h"
    #include "hisax_if.h"
    #include <linux/skbuff.h>
    diff --git a/drivers/isdn/i4l/Kconfig b/drivers/isdn/i4l/Kconfig
    index ed3510f..dd744ff 100644
    --- a/drivers/isdn/i4l/Kconfig
    +++ b/drivers/isdn/i4l/Kconfig
    @@ -2,6 +2,8 @@
    # Old ISDN4Linux config
    #

    +if ISDN_I4L
    +
    config ISDN_PPP
    bool "Support synchronous PPP"
    depends on INET
    @@ -135,3 +137,12 @@ source "drivers/isdn/act2000/Kconfig"
    source "drivers/isdn/hysdn/Kconfig"

    endmenu
    +# end ISDN_I4L
    +endif
    +
    +config ISDN_HDLC
    + tristate
    + depends on HISAX_ST5481
    + select CRC_CCITT
    + select BITREVERSE
    +
    diff --git a/drivers/isdn/i4l/Makefile b/drivers/isdn/i4l/Makefile
    index 49a06c0..cb9d3bb 100644
    --- a/drivers/isdn/i4l/Makefile
    +++ b/drivers/isdn/i4l/Makefile
    @@ -4,6 +4,7 @@

    obj-$(CONFIG_ISDN_I4L) += isdn.o
    obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o
    +obj-$(CONFIG_ISDN_HDLC) += isdnhdlc.o

    # Multipart objects.

    diff --git a/drivers/isdn/i4l/isdnhdlc.c b/drivers/isdn/i4l/isdnhdlc.c
    new file mode 100644
    index 0000000..44ec741
    --- /dev/null
    +++ b/drivers/isdn/i4l/isdnhdlc.c
    @@ -0,0 +1,603 @@
    +/*
    + * isdnhdlc.c -- General purpose ISDN HDLC decoder.
    + *
    + *Copyright (C) 2002 Wolfgang Mües <wolfgang@iksw-muees.de>
    + * 2001 Frode Isaksen <fisaksen@bewan.com>
    + * 2001 Kai Germaschewski <kai.germaschewski@gmx.de>
    + *
    + * This program is free software; you can redistribute it and/or modify
    + * it under the terms of the GNU General Public License as published by
    + * the Free Software Foundation; either version 2 of the License, or
    + * (at your option) any later version.
    + *
    + * This program is distributed in the hope that it will be useful,
    + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    + * GNU General Public License for more details.
    + *
    + * You should have received a copy of the GNU General Public License
    + * along with this program; if not, write to the Free Software
    + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    + */
    +
    +#include <linux/module.h>
    +#include <linux/init.h>
    +#include <linux/crc-ccitt.h>
    +#include <linux/isdn/hdlc.h>
    +
    +/*-------------------------------------------------------------------*/
    +
    +MODULE_AUTHOR("Wolfgang Mües <wolfgang@iksw-muees.de>, "
    + "Frode Isaksen <fisaksen@bewan.com>, "
    + "Kai Germaschewski <kai.germaschewski@gmx.de>");
    +MODULE_DESCRIPTION("General purpose ISDN HDLC decoder");
    +MODULE_LICENSE("GPL");
    +
    +/*-------------------------------------------------------------------*/
    +
    +enum {
    + HDLC_FAST_IDLE,HDLC_GET_FLAG_B0,HDLC_GETFLAG_B1A6,HDLC_GETFLAG_B7,
    + HDLC_GET_DATA,HDLC_FAST_FLAG
    +};
    +
    +enum {
    + HDLC_SEND_DATA,HDLC_SEND_CRC1,HDLC_SEND_FAST_FLAG,
    + HDLC_SEND_FIRST_FLAG,HDLC_SEND_CRC2,HDLC_SEND_CLOSING_FLAG,
    + HDLC_SEND_IDLE1,HDLC_SEND_FAST_IDLE,HDLC_SENDFLAG_B0,
    + HDLC_SENDFLAG_B1A6,HDLC_SENDFLAG_B7,STOPPED
    +};
    +
    +void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56)
    +{
    + hdlc->bit_shift = 0;
    + hdlc->hdlc_bits1 = 0;
    + hdlc->data_bits = 0;
    + hdlc->ffbit_shift = 0;
    + hdlc->data_received = 0;
    + hdlc->state = HDLC_GET_DATA;
    + hdlc->do_adapt56 = do_adapt56;
    + hdlc->dchannel = 0;
    + hdlc->crc = 0;
    + hdlc->cbin = 0;
    + hdlc->shift_reg = 0;
    + hdlc->ffvalue = 0;
    + hdlc->dstpos = 0;
    +}
    +
    +void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc, int is_d_channel, int do_adapt56)
    +{
    + hdlc->bit_shift = 0;
    + hdlc->hdlc_bits1 = 0;
    + hdlc->data_bits = 0;
    + hdlc->ffbit_shift = 0;
    + hdlc->data_received = 0;
    + hdlc->do_closing = 0;
    + hdlc->ffvalue = 0;
    + if (is_d_channel) {
    + hdlc->dchannel = 1;
    + hdlc->state = HDLC_SEND_FIRST_FLAG;
    + } else {
    + hdlc->dchannel = 0;
    + hdlc->state = HDLC_SEND_FAST_FLAG;
    + hdlc->ffvalue = 0x7e;
    + }
    + hdlc->cbin = 0x7e;
    + hdlc->bit_shift = 0;
    + if(do_adapt56){
    + hdlc->do_adapt56 = 1;
    + hdlc->data_bits = 0;
    + hdlc->state = HDLC_SENDFLAG_B0;
    + } else {
    + hdlc->do_adapt56 = 0;
    + hdlc->data_bits = 8;
    + }
    + hdlc->shift_reg = 0;
    +}
    +
    +/*
    + isdnhdlc_decode - decodes HDLC frames from a transparent bit stream.
    +
    + The source buffer is scanned for valid HDLC frames looking for
    + flags (01111110) to indicate the start of a frame. If the start of
    + the frame is found, the bit stuffing is removed (0 after 5 1's).
    + When a new flag is found, the complete frame has been received
    + and the CRC is checked.
    + If a valid frame is found, the function returns the frame length
    + excluding the CRC with the bit HDLC_END_OF_FRAME set.
    + If the beginning of a valid frame is found, the function returns
    + the length.
    + If a framing error is found (too many 1s and not a flag) the function
    + returns the length with the bit HDLC_FRAMING_ERROR set.
    + If a CRC error is found the function returns the length with the
    + bit HDLC_CRC_ERROR set.
    + If the frame length exceeds the destination buffer size, the function
    + returns the length with the bit HDLC_LENGTH_ERROR set.
    +
    + src - source buffer
    + slen - source buffer length
    + count - number of bytes removed (decoded) from the source buffer
    + dst _ destination buffer
    + dsize - destination buffer size
    + returns - number of decoded bytes in the destination buffer and status
    + flag.
    + */
    +int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src,
    + int slen, int *count, unsigned char *dst, int dsize)
    +{
    + int status=0;
    +
    + static const unsigned char fast_flag[]={
    + 0x00,0x00,0x00,0x20,0x30,0x38,0x3c,0x3e,0x3f
    + };
    +
    + static const unsigned char fast_flag_value[]={
    + 0x00,0x7e,0xfc,0xf9,0xf3,0xe7,0xcf,0x9f,0x3f
    + };
    +
    + static const unsigned char fast_abort[]={
    + 0x00,0x00,0x80,0xc0,0xe0,0xf0,0xf8,0xfc,0xfe,0xff
    + };
    +
    + *count = slen;
    +
    + while(slen > 0){
    + if(hdlc->bit_shift==0){
    + hdlc->cbin = *src++;
    + slen--;
    + hdlc->bit_shift = 8;
    + if(hdlc->do_adapt56){
    + hdlc->bit_shift --;
    + }
    + }
    +
    + switch(hdlc->state){
    + case STOPPED:
    + return 0;
    + case HDLC_FAST_IDLE:
    + if(hdlc->cbin == 0xff){
    + hdlc->bit_shift = 0;
    + break;
    + }
    + hdlc->state = HDLC_GET_FLAG_B0;
    + hdlc->hdlc_bits1 = 0;
    + hdlc->bit_shift = 8;
    + break;
    + case HDLC_GET_FLAG_B0:
    + if(!(hdlc->cbin & 0x80)) {
    + hdlc->state = HDLC_GETFLAG_B1A6;
    + hdlc->hdlc_bits1 = 0;
    + } else {
    + if(!hdlc->do_adapt56){
    + if(++hdlc->hdlc_bits1 >=8 ) if(hdlc->bit_shift==1)
    + hdlc->state = HDLC_FAST_IDLE;
    + }
    + }
    + hdlc->cbin<<=1;
    + hdlc->bit_shift --;
    + break;
    + case HDLC_GETFLAG_B1A6:
    + if(hdlc->cbin & 0x80){
    + hdlc->hdlc_bits1++;
    + if(hdlc->hdlc_bits1==6){
    + hdlc->state = HDLC_GETFLAG_B7;
    + }
    + } else {
    + hdlc->hdlc_bits1 = 0;
    + }
    + hdlc->cbin<<=1;
    + hdlc->bit_shift --;
    + break;
    + case HDLC_GETFLAG_B7:
    + if(hdlc->cbin & 0x80) {
    + hdlc->state = HDLC_GET_FLAG_B0;
    + } else {
    + hdlc->state = HDLC_GET_DATA;
    + hdlc->crc = 0xffff;
    + hdlc->shift_reg = 0;
    + hdlc->hdlc_bits1 = 0;
    + hdlc->data_bits = 0;
    + hdlc->data_received = 0;
    + }
    + hdlc->cbin<<=1;
    + hdlc->bit_shift --;
    + break;
    + case HDLC_GET_DATA:
    + if(hdlc->cbin & 0x80){
    + hdlc->hdlc_bits1++;
    + switch(hdlc->hdlc_bits1){
    + case 6:
    + break;
    + case 7:
    + if(hdlc->data_received) {
    + // bad frame
    + status = -HDLC_FRAMING_ERROR;
    + }
    + if(!hdlc->do_adapt56){
    + if(hdlc->cbin==fast_abort[hdlc->bit_shift+1]){
    + hdlc->state = HDLC_FAST_IDLE;
    + hdlc->bit_shift=1;
    + break;
    + }
    + } else {
    + hdlc->state = HDLC_GET_FLAG_B0;
    + }
    + break;
    + default:
    + hdlc->shift_reg>>=1;
    + hdlc->shift_reg |= 0x80;
    + hdlc->data_bits++;
    + break;
    + }
    + } else {
    + switch(hdlc->hdlc_bits1){
    + case 5:
    + break;
    + case 6:
    + if(hdlc->data_received){
    + if (hdlc->dstpos < 2) {
    + status = -HDLC_FRAMING_ERROR;
    + } else if (hdlc->crc != 0xf0b8){
    + // crc error
    + status = -HDLC_CRC_ERROR;
    + } else {
    + // remove CRC
    + hdlc->dstpos -= 2;
    + // good frame
    + status = hdlc->dstpos;
    + }
    + }
    + hdlc->crc = 0xffff;
    + hdlc->shift_reg = 0;
    + hdlc->data_bits = 0;
    + if(!hdlc->do_adapt56){
    + if(hdlc->cbin==fast_flag[hdlc->bit_shift]){
    + hdlc->ffvalue = fast_flag_value[hdlc->bit_shift];
    + hdlc->state = HDLC_FAST_FLAG;
    + hdlc->ffbit_shift = hdlc->bit_shift;
    + hdlc->bit_shift = 1;
    + } else {
    + hdlc->state = HDLC_GET_DATA;
    + hdlc->data_received = 0;
    + }
    + } else {
    + hdlc->state = HDLC_GET_DATA;
    + hdlc->data_received = 0;
    + }
    + break;
    + default:
    + hdlc->shift_reg>>=1;
    + hdlc->data_bits++;
    + break;
    + }
    + hdlc->hdlc_bits1 = 0;
    + }
    + if (status) {
    + hdlc->dstpos = 0;
    + *count -= slen;
    + hdlc->cbin <<= 1;
    + hdlc->bit_shift--;
    + return status;
    + }
    + if(hdlc->data_bits==8){
    + hdlc->data_bits = 0;
    + hdlc->data_received = 1;
    + hdlc->crc = crc_ccitt_byte(hdlc->crc, hdlc->shift_reg);
    +
    + // good byte received
    + if (hdlc->dstpos < dsize) {
    + dst[hdlc->dstpos++] = hdlc->shift_reg;
    + } else {
    + // frame too long
    + status = -HDLC_LENGTH_ERROR;
    + hdlc->dstpos = 0;
    + }
    + }
    + hdlc->cbin <<= 1;
    + hdlc->bit_shift--;
    + break;
    + case HDLC_FAST_FLAG:
    + if(hdlc->cbin==hdlc->ffvalue){
    + hdlc->bit_shift = 0;
    + break;
    + } else {
    + if(hdlc->cbin == 0xff){
    + hdlc->state = HDLC_FAST_IDLE;
    + hdlc->bit_shift=0;
    + } else if(hdlc->ffbit_shift==8){
    + hdlc->state = HDLC_GETFLAG_B7;
    + break;
    + } else {
    + hdlc->shift_reg = fast_abort[hdlc->ffbit_shift-1];
    + hdlc->hdlc_bits1 = hdlc->ffbit_shift-2;
    + if(hdlc->hdlc_bits1<0)hdlc->hdlc_bits1 = 0;
    + hdlc->data_bits = hdlc->ffbit_shift-1;
    + hdlc->state = HDLC_GET_DATA;
    + hdlc->data_received = 0;
    + }
    + }
    + break;
    + default:
    + break;
    + }
    + }
    + *count -= slen;
    + return 0;
    +}
    +
    +/*
    + isdnhdlc_encode - encodes HDLC frames to a transparent bit stream.
    +
    + The bit stream starts with a beginning flag (01111110). After
    + that each byte is added to the bit stream with bit stuffing added
    + (0 after 5 1's).
    + When the last byte has been removed from the source buffer, the
    + CRC (2 bytes is added) and the frame terminates with the ending flag.
    + For the dchannel, the idle character (all 1's) is also added at the end.
    + If this function is called with empty source buffer (slen=0), flags or
    + idle character will be generated.
    +
    + src - source buffer
    + slen - source buffer length
    + count - number of bytes removed (encoded) from source buffer
    + dst _ destination buffer
    + dsize - destination buffer size
    + returns - number of encoded bytes in the destination buffer
    +*/
    +int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const unsigned char *src,
    + unsigned short slen, int *count,
    + unsigned char *dst, int dsize)
    +{
    + static const unsigned char xfast_flag_value[] = {
    + 0x7e,0x3f,0x9f,0xcf,0xe7,0xf3,0xf9,0xfc,0x7e
    + };
    +
    + int len = 0;
    +
    + *count = slen;
    +
    + while (dsize > 0) {
    + if(hdlc->bit_shift==0){
    + if(slen && !hdlc->do_closing){
    + hdlc->shift_reg = *src++;
    + slen--;
    + if (slen == 0)
    + hdlc->do_closing = 1; /* closing sequence, CRC + flag(s) */
    + hdlc->bit_shift = 8;
    + } else {
    + if(hdlc->state == HDLC_SEND_DATA){
    + if(hdlc->data_received){
    + hdlc->state = HDLC_SEND_CRC1;
    + hdlc->crc ^= 0xffff;
    + hdlc->bit_shift = 8;
    + hdlc->shift_reg = hdlc->crc & 0xff;
    + } else if(!hdlc->do_adapt56){
    + hdlc->state = HDLC_SEND_FAST_FLAG;
    + } else {
    + hdlc->state = HDLC_SENDFLAG_B0;
    + }
    + }
    +
    + }
    + }
    +
    + switch(hdlc->state){
    + case STOPPED:
    + while (dsize--)
    + *dst++ = 0xff;
    +
    + return dsize;
    + case HDLC_SEND_FAST_FLAG:
    + hdlc->do_closing = 0;
    + if(slen == 0){
    + *dst++ = hdlc->ffvalue;
    + len++;
    + dsize--;
    + break;
    + }
    + if(hdlc->bit_shift==8){
    + hdlc->cbin = hdlc->ffvalue>>(8-hdlc->data_bits);
    + hdlc->state = HDLC_SEND_DATA;
    + hdlc->crc = 0xffff;
    + hdlc->hdlc_bits1 = 0;
    + hdlc->data_received = 1;
    + }
    + break;
    + case HDLC_SENDFLAG_B0:
    + hdlc->do_closing = 0;
    + hdlc->cbin <<= 1;
    + hdlc->data_bits++;
    + hdlc->hdlc_bits1 = 0;
    + hdlc->state = HDLC_SENDFLAG_B1A6;
    + break;
    + case HDLC_SENDFLAG_B1A6:
    + hdlc->cbin <<= 1;
    + hdlc->data_bits++;
    + hdlc->cbin++;
    + if(++hdlc->hdlc_bits1 == 6)
    + hdlc->state = HDLC_SENDFLAG_B7;
    + break;
    + case HDLC_SENDFLAG_B7:
    + hdlc->cbin <<= 1;
    + hdlc->data_bits++;
    + if(slen == 0){
    + hdlc->state = HDLC_SENDFLAG_B0;
    + break;
    + }
    + if(hdlc->bit_shift==8){
    + hdlc->state = HDLC_SEND_DATA;
    + hdlc->crc = 0xffff;
    + hdlc->hdlc_bits1 = 0;
    + hdlc->data_received = 1;
    + }
    + break;
    + case HDLC_SEND_FIRST_FLAG:
    + hdlc->data_received = 1;
    + if(hdlc->data_bits==8){
    + hdlc->state = HDLC_SEND_DATA;
    + hdlc->crc = 0xffff;
    + hdlc->hdlc_bits1 = 0;
    + break;
    + }
    + hdlc->cbin <<= 1;
    + hdlc->data_bits++;
    + if(hdlc->shift_reg & 0x01)
    + hdlc->cbin++;
    + hdlc->shift_reg >>= 1;
    + hdlc->bit_shift--;
    + if(hdlc->bit_shift==0){
    + hdlc->state = HDLC_SEND_DATA;
    + hdlc->crc = 0xffff;
    + hdlc->hdlc_bits1 = 0;
    + }
    + break;
    + case HDLC_SEND_DATA:
    + hdlc->cbin <<= 1;
    + hdlc->data_bits++;
    + if(hdlc->hdlc_bits1 == 5){
    + hdlc->hdlc_bits1 = 0;
    + break;
    + }
    + if(hdlc->bit_shift==8){
    + hdlc->crc = crc_ccitt_byte(hdlc->crc, hdlc->shift_reg);
    + }
    + if(hdlc->shift_reg & 0x01){
    + hdlc->hdlc_bits1++;
    + hdlc->cbin++;
    + hdlc->shift_reg >>= 1;
    + hdlc->bit_shift--;
    + } else {
    + hdlc->hdlc_bits1 = 0;
    + hdlc->shift_reg >>= 1;
    + hdlc->bit_shift--;
    + }
    + break;
    + case HDLC_SEND_CRC1:
    + hdlc->cbin <<= 1;
    + hdlc->data_bits++;
    + if(hdlc->hdlc_bits1 == 5){
    + hdlc->hdlc_bits1 = 0;
    + break;
    + }
    + if(hdlc->shift_reg & 0x01){
    + hdlc->hdlc_bits1++;
    + hdlc->cbin++;
    + hdlc->shift_reg >>= 1;
    + hdlc->bit_shift--;
    + } else {
    + hdlc->hdlc_bits1 = 0;
    + hdlc->shift_reg >>= 1;
    + hdlc->bit_shift--;
    + }
    + if(hdlc->bit_shift==0){
    + hdlc->shift_reg = (hdlc->crc >> 8);
    + hdlc->state = HDLC_SEND_CRC2;
    + hdlc->bit_shift = 8;
    + }
    + break;
    + case HDLC_SEND_CRC2:
    + hdlc->cbin <<= 1;
    + hdlc->data_bits++;
    + if(hdlc->hdlc_bits1 == 5){
    + hdlc->hdlc_bits1 = 0;
    + break;
    + }
    + if(hdlc->shift_reg & 0x01){
    + hdlc->hdlc_bits1++;
    + hdlc->cbin++;
    + hdlc->shift_reg >>= 1;
    + hdlc->bit_shift--;
    + } else {
    + hdlc->hdlc_bits1 = 0;
    + hdlc->shift_reg >>= 1;
    + hdlc->bit_shift--;
    + }
    + if(hdlc->bit_shift==0){
    + hdlc->shift_reg = 0x7e;
    + hdlc->state = HDLC_SEND_CLOSING_FLAG;
    + hdlc->bit_shift = 8;
    + }
    + break;
    + case HDLC_SEND_CLOSING_FLAG:
    + hdlc->cbin <<= 1;
    + hdlc->data_bits++;
    + if(hdlc->hdlc_bits1 == 5){
    + hdlc->hdlc_bits1 = 0;
    + break;
    + }
    + if(hdlc->shift_reg & 0x01){
    + hdlc->cbin++;
    + }
    + hdlc->shift_reg >>= 1;
    + hdlc->bit_shift--;
    + if(hdlc->bit_shift==0){
    + hdlc->ffvalue = xfast_flag_value[hdlc->data_bits];
    + if(hdlc->dchannel){
    + hdlc->ffvalue = 0x7e;
    + hdlc->state = HDLC_SEND_IDLE1;
    + hdlc->bit_shift = 8-hdlc->data_bits;
    + if(hdlc->bit_shift==0)
    + hdlc->state = HDLC_SEND_FAST_IDLE;
    + } else {
    + if(!hdlc->do_adapt56){
    + hdlc->state = HDLC_SEND_FAST_FLAG;
    + hdlc->data_received = 0;
    + } else {
    + hdlc->state = HDLC_SENDFLAG_B0;
    + hdlc->data_received = 0;
    + }
    + // Finished with this frame, send flags
    + if (dsize > 1) dsize = 1;
    + }
    + }
    + break;
    + case HDLC_SEND_IDLE1:
    + hdlc->do_closing = 0;
    + hdlc->cbin <<= 1;
    + hdlc->cbin++;
    + hdlc->data_bits++;
    + hdlc->bit_shift--;
    + if(hdlc->bit_shift==0){
    + hdlc->state = HDLC_SEND_FAST_IDLE;
    + hdlc->bit_shift = 0;
    + }
    + break;
    + case HDLC_SEND_FAST_IDLE:
    + hdlc->do_closing = 0;
    + hdlc->cbin = 0xff;
    + hdlc->data_bits = 8;
    + if(hdlc->bit_shift == 8){
    + hdlc->cbin = 0x7e;
    + hdlc->state = HDLC_SEND_FIRST_FLAG;
    + } else {
    + *dst++ = hdlc->cbin;
    + hdlc->bit_shift = hdlc->data_bits = 0;
    + len++;
    + dsize = 0;
    + }
    + break;
    + default:
    + break;
    + }
    + if(hdlc->do_adapt56){
    + if(hdlc->data_bits==7){
    + hdlc->cbin <<= 1;
    + hdlc->cbin++;
    + hdlc->data_bits++;
    + }
    + }
    + if(hdlc->data_bits==8){
    + *dst++ = hdlc->cbin;
    + hdlc->data_bits = 0;
    + len++;
    + dsize--;
    + }
    + }
    + *count -= slen;
    +
    + return len;
    +}
    +
    +EXPORT_SYMBOL(isdnhdlc_rcv_init);
    +EXPORT_SYMBOL(isdnhdlc_decode);
    +EXPORT_SYMBOL(isdnhdlc_out_init);
    +EXPORT_SYMBOL(isdnhdlc_encode);
    diff --git a/include/linux/isdn/hdlc.h b/include/linux/isdn/hdlc.h
    new file mode 100644
    index 0000000..cf0a95a
    --- /dev/null
    +++ b/include/linux/isdn/hdlc.h
    @@ -0,0 +1,70 @@
    +/*
    + * isdnhdlc.h -- General purpose ISDN HDLC decoder.
    + *
    + * Implementation of a HDLC decoder/encoder in software.
    + * Neccessary because some ISDN devices don't have HDLC
    + * controllers. Also included: a bit reversal table.
    + *
    + *Copyright (C) 2002 Wolfgang Mües <wolfgang@iksw-muees.de>
    + * 2001 Frode Isaksen <fisaksen@bewan.com>
    + * 2001 Kai Germaschewski <kai.germaschewski@gmx.de>
    + *
    + * This program is free software; you can redistribute it and/or modify
    + * it under the terms of the GNU General Public License as published by
    + * the Free Software Foundation; either version 2 of the License, or
    + * (at your option) any later version.
    + *
    + * This program is distributed in the hope that it will be useful,
    + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    + * GNU General Public License for more details.
    + *
    + * You should have received a copy of the GNU General Public License
    + * along with this program; if not, write to the Free Software
    + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    + */
    +
    +#ifndef __ISDNHDLC_H__
    +#define __ISDNHDLC_H__
    +
    +struct isdnhdlc_vars {
    + int bit_shift;
    + int hdlc_bits1;
    + int data_bits;
    + int ffbit_shift; // encoding only
    + int state;
    + int dstpos;
    +
    + unsigned short crc;
    +
    + unsigned char cbin;
    + unsigned char shift_reg;
    + unsigned char ffvalue;
    +
    + unsigned int data_received:1; // set if transferring data
    + unsigned int dchannel:1; // set if D channel (send idle instead of flags)
    + unsigned int do_adapt56:1; // set if 56K adaptation
    + unsigned int do_closing:1; // set if in closing phase (need to send CRC + flag
    +};
    +
    +
    +/*
    + The return value from isdnhdlc_decode is
    + the frame length, 0 if no complete frame was decoded,
    + or a negative error number
    +*/
    +#define HDLC_FRAMING_ERROR 1
    +#define HDLC_CRC_ERROR 2
    +#define HDLC_LENGTH_ERROR 3
    +
    +extern void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56);
    +
    +extern int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src, int slen,int *count,
    + unsigned char *dst, int dsize);
    +
    +extern void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc,int is_d_channel,int do_adapt56);
    +
    +extern int isdnhdlc_encode (struct isdnhdlc_vars *hdlc,const unsigned char *src,unsigned short slen,int *count,
    + unsigned char *dst,int dsize);
    +
    +#endif /* __ISDNHDLC_H__ */
    --
    1.6.0.2
    --
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