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linux-sg2042/drivers/isdn/gigaset/isocdata.c

1010 lines
36 KiB
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/*
* Common data handling layer for bas_gigaset
*
* Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>,
* Hansjoerg Lipp <hjlipp@web.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.
* =====================================================================
*/
#include "gigaset.h"
#include <linux/crc-ccitt.h>
#include <linux/bitrev.h>
/* access methods for isowbuf_t */
/* ============================ */
/* initialize buffer structure
*/
void gigaset_isowbuf_init(struct isowbuf_t *iwb, unsigned char idle)
{
iwb->read = 0;
iwb->nextread = 0;
iwb->write = 0;
atomic_set(&iwb->writesem, 1);
iwb->wbits = 0;
iwb->idle = idle;
memset(iwb->data + BAS_OUTBUFSIZE, idle, BAS_OUTBUFPAD);
}
/* compute number of bytes which can be appended to buffer
* so that there is still room to append a maximum frame of flags
*/
static inline int isowbuf_freebytes(struct isowbuf_t *iwb)
{
int read, write, freebytes;
read = iwb->read;
write = iwb->write;
freebytes = read - write;
if (freebytes > 0) {
/* no wraparound: need padding space within regular area */
return freebytes - BAS_OUTBUFPAD;
} else if (read < BAS_OUTBUFPAD) {
/* wraparound: can use space up to end of regular area */
return BAS_OUTBUFSIZE - write;
} else {
/* following the wraparound yields more space */
return freebytes + BAS_OUTBUFSIZE - BAS_OUTBUFPAD;
}
}
/* start writing
* acquire the write semaphore
* return 0 if acquired, <0 if busy
*/
static inline int isowbuf_startwrite(struct isowbuf_t *iwb)
{
if (!atomic_dec_and_test(&iwb->writesem)) {
atomic_inc(&iwb->writesem);
gig_dbg(DEBUG_ISO, "%s: couldn't acquire iso write semaphore",
__func__);
return -EBUSY;
}
gig_dbg(DEBUG_ISO,
"%s: acquired iso write semaphore, data[write]=%02x, nbits=%d",
__func__, iwb->data[iwb->write], iwb->wbits);
return 0;
}
/* finish writing
* release the write semaphore
* returns the current write position
*/
static inline int isowbuf_donewrite(struct isowbuf_t *iwb)
{
int write = iwb->write;
atomic_inc(&iwb->writesem);
return write;
}
/* append bits to buffer without any checks
* - data contains bits to append, starting at LSB
* - nbits is number of bits to append (0..24)
* must be called with the write semaphore held
* If more than nbits bits are set in data, the extraneous bits are set in the
* buffer too, but the write position is only advanced by nbits.
*/
static inline void isowbuf_putbits(struct isowbuf_t *iwb, u32 data, int nbits)
{
int write = iwb->write;
data <<= iwb->wbits;
data |= iwb->data[write];
nbits += iwb->wbits;
while (nbits >= 8) {
iwb->data[write++] = data & 0xff;
write %= BAS_OUTBUFSIZE;
data >>= 8;
nbits -= 8;
}
iwb->wbits = nbits;
iwb->data[write] = data & 0xff;
iwb->write = write;
}
/* put final flag on HDLC bitstream
* also sets the idle fill byte to the correspondingly shifted flag pattern
* must be called with the write semaphore held
*/
static inline void isowbuf_putflag(struct isowbuf_t *iwb)
{
int write;
/* add two flags, thus reliably covering one byte */
isowbuf_putbits(iwb, 0x7e7e, 8);
/* recover the idle flag byte */
write = iwb->write;
iwb->idle = iwb->data[write];
gig_dbg(DEBUG_ISO, "idle fill byte %02x", iwb->idle);
/* mask extraneous bits in buffer */
iwb->data[write] &= (1 << iwb->wbits) - 1;
}
/* retrieve a block of bytes for sending
* The requested number of bytes is provided as a contiguous block.
* If necessary, the frame is filled to the requested number of bytes
* with the idle value.
* returns offset to frame, < 0 on busy or error
*/
int gigaset_isowbuf_getbytes(struct isowbuf_t *iwb, int size)
{
int read, write, limit, src, dst;
unsigned char pbyte;
read = iwb->nextread;
write = iwb->write;
if (likely(read == write)) {
/* return idle frame */
return read < BAS_OUTBUFPAD ?
BAS_OUTBUFSIZE : read - BAS_OUTBUFPAD;
}
limit = read + size;
gig_dbg(DEBUG_STREAM, "%s: read=%d write=%d limit=%d",
__func__, read, write, limit);
#ifdef CONFIG_GIGASET_DEBUG
if (unlikely(size < 0 || size > BAS_OUTBUFPAD)) {
pr_err("invalid size %d\n", size);
return -EINVAL;
}
#endif
if (read < write) {
/* no wraparound in valid data */
if (limit >= write) {
/* append idle frame */
if (isowbuf_startwrite(iwb) < 0)
return -EBUSY;
/* write position could have changed */
write = iwb->write;
if (limit >= write) {
pbyte = iwb->data[write]; /* save
partial byte */
limit = write + BAS_OUTBUFPAD;
gig_dbg(DEBUG_STREAM,
"%s: filling %d->%d with %02x",
__func__, write, limit, iwb->idle);
if (write + BAS_OUTBUFPAD < BAS_OUTBUFSIZE)
memset(iwb->data + write, iwb->idle,
BAS_OUTBUFPAD);
else {
/* wraparound, fill entire pad area */
memset(iwb->data + write, iwb->idle,
BAS_OUTBUFSIZE + BAS_OUTBUFPAD
- write);
limit = 0;
}
gig_dbg(DEBUG_STREAM,
"%s: restoring %02x at %d",
__func__, pbyte, limit);
iwb->data[limit] = pbyte; /* restore
partial byte */
iwb->write = limit;
}
isowbuf_donewrite(iwb);
}
} else {
/* valid data wraparound */
if (limit >= BAS_OUTBUFSIZE) {
/* copy wrapped part into pad area */
src = 0;
dst = BAS_OUTBUFSIZE;
while (dst < limit && src < write)
iwb->data[dst++] = iwb->data[src++];
if (dst <= limit) {
/* fill pad area with idle byte */
memset(iwb->data + dst, iwb->idle,
BAS_OUTBUFSIZE + BAS_OUTBUFPAD - dst);
}
limit = src;
}
}
iwb->nextread = limit;
return read;
}
/* dump_bytes
* write hex bytes to syslog for debugging
*/
static inline void dump_bytes(enum debuglevel level, const char *tag,
unsigned char *bytes, int count)
{
#ifdef CONFIG_GIGASET_DEBUG
unsigned char c;
static char dbgline[3 * 32 + 1];
int i = 0;
if (!(gigaset_debuglevel & level))
return;
while (count-- > 0) {
if (i > sizeof(dbgline) - 4) {
dbgline[i] = '\0';
gig_dbg(level, "%s:%s", tag, dbgline);
i = 0;
}
c = *bytes++;
dbgline[i] = (i && !(i % 12)) ? '-' : ' ';
i++;
dbgline[i++] = hex_asc_hi(c);
dbgline[i++] = hex_asc_lo(c);
}
dbgline[i] = '\0';
gig_dbg(level, "%s:%s", tag, dbgline);
#endif
}
/*============================================================================*/
/* bytewise HDLC bitstuffing via table lookup
* lookup table: 5 subtables for 0..4 preceding consecutive '1' bits
* index: 256*(number of preceding '1' bits) + (next byte to stuff)
* value: bit 9.. 0 = result bits
* bit 12..10 = number of trailing '1' bits in result
* bit 14..13 = number of bits added by stuffing
*/
static const u16 stufftab[5 * 256] = {
/* previous 1s = 0: */
0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x201f,
0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x205f,
0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x209f,
0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20df,
0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x048f,
0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x251f,
0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x04af,
0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x255f,
0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x08cf,
0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x299f,
0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x0cef,
0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x2ddf,
/* previous 1s = 1: */
0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x200f,
0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x202f,
0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x204f,
0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x206f,
0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x208f,
0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20af,
0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20cf,
0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20ef,
0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x250f,
0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x252f,
0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x254f,
0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x256f,
0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x298f,
0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29af,
0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dcf,
0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x31ef,
/* previous 1s = 2: */
0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x2007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x2017,
0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x2027, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x2037,
0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x2047, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x2057,
0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x2067, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x2077,
0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x2087, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x2097,
0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x20a7, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20b7,
0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x20c7, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20d7,
0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x20e7, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20f7,
0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x2507, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x2517,
0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x2527, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x2537,
0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x2547, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x2557,
0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x2567, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x2577,
0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x2987, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x2997,
0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x29a7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29b7,
0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dc7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dd7,
0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x31e7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x41f7,
/* previous 1s = 3: */
0x0000, 0x0001, 0x0002, 0x2003, 0x0004, 0x0005, 0x0006, 0x200b, 0x0008, 0x0009, 0x000a, 0x2013, 0x000c, 0x000d, 0x000e, 0x201b,
0x0010, 0x0011, 0x0012, 0x2023, 0x0014, 0x0015, 0x0016, 0x202b, 0x0018, 0x0019, 0x001a, 0x2033, 0x001c, 0x001d, 0x001e, 0x203b,
0x0020, 0x0021, 0x0022, 0x2043, 0x0024, 0x0025, 0x0026, 0x204b, 0x0028, 0x0029, 0x002a, 0x2053, 0x002c, 0x002d, 0x002e, 0x205b,
0x0030, 0x0031, 0x0032, 0x2063, 0x0034, 0x0035, 0x0036, 0x206b, 0x0038, 0x0039, 0x003a, 0x2073, 0x003c, 0x003d, 0x203e, 0x207b,
0x0040, 0x0041, 0x0042, 0x2083, 0x0044, 0x0045, 0x0046, 0x208b, 0x0048, 0x0049, 0x004a, 0x2093, 0x004c, 0x004d, 0x004e, 0x209b,
0x0050, 0x0051, 0x0052, 0x20a3, 0x0054, 0x0055, 0x0056, 0x20ab, 0x0058, 0x0059, 0x005a, 0x20b3, 0x005c, 0x005d, 0x005e, 0x20bb,
0x0060, 0x0061, 0x0062, 0x20c3, 0x0064, 0x0065, 0x0066, 0x20cb, 0x0068, 0x0069, 0x006a, 0x20d3, 0x006c, 0x006d, 0x006e, 0x20db,
0x0070, 0x0071, 0x0072, 0x20e3, 0x0074, 0x0075, 0x0076, 0x20eb, 0x0078, 0x0079, 0x007a, 0x20f3, 0x207c, 0x207d, 0x20be, 0x40fb,
0x0480, 0x0481, 0x0482, 0x2503, 0x0484, 0x0485, 0x0486, 0x250b, 0x0488, 0x0489, 0x048a, 0x2513, 0x048c, 0x048d, 0x048e, 0x251b,
0x0490, 0x0491, 0x0492, 0x2523, 0x0494, 0x0495, 0x0496, 0x252b, 0x0498, 0x0499, 0x049a, 0x2533, 0x049c, 0x049d, 0x049e, 0x253b,
0x04a0, 0x04a1, 0x04a2, 0x2543, 0x04a4, 0x04a5, 0x04a6, 0x254b, 0x04a8, 0x04a9, 0x04aa, 0x2553, 0x04ac, 0x04ad, 0x04ae, 0x255b,
0x04b0, 0x04b1, 0x04b2, 0x2563, 0x04b4, 0x04b5, 0x04b6, 0x256b, 0x04b8, 0x04b9, 0x04ba, 0x2573, 0x04bc, 0x04bd, 0x253e, 0x257b,
0x08c0, 0x08c1, 0x08c2, 0x2983, 0x08c4, 0x08c5, 0x08c6, 0x298b, 0x08c8, 0x08c9, 0x08ca, 0x2993, 0x08cc, 0x08cd, 0x08ce, 0x299b,
0x08d0, 0x08d1, 0x08d2, 0x29a3, 0x08d4, 0x08d5, 0x08d6, 0x29ab, 0x08d8, 0x08d9, 0x08da, 0x29b3, 0x08dc, 0x08dd, 0x08de, 0x29bb,
0x0ce0, 0x0ce1, 0x0ce2, 0x2dc3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dcb, 0x0ce8, 0x0ce9, 0x0cea, 0x2dd3, 0x0cec, 0x0ced, 0x0cee, 0x2ddb,
0x10f0, 0x10f1, 0x10f2, 0x31e3, 0x10f4, 0x10f5, 0x10f6, 0x31eb, 0x20f8, 0x20f9, 0x20fa, 0x41f3, 0x257c, 0x257d, 0x29be, 0x46fb,
/* previous 1s = 4: */
0x0000, 0x2001, 0x0002, 0x2005, 0x0004, 0x2009, 0x0006, 0x200d, 0x0008, 0x2011, 0x000a, 0x2015, 0x000c, 0x2019, 0x000e, 0x201d,
0x0010, 0x2021, 0x0012, 0x2025, 0x0014, 0x2029, 0x0016, 0x202d, 0x0018, 0x2031, 0x001a, 0x2035, 0x001c, 0x2039, 0x001e, 0x203d,
0x0020, 0x2041, 0x0022, 0x2045, 0x0024, 0x2049, 0x0026, 0x204d, 0x0028, 0x2051, 0x002a, 0x2055, 0x002c, 0x2059, 0x002e, 0x205d,
0x0030, 0x2061, 0x0032, 0x2065, 0x0034, 0x2069, 0x0036, 0x206d, 0x0038, 0x2071, 0x003a, 0x2075, 0x003c, 0x2079, 0x203e, 0x407d,
0x0040, 0x2081, 0x0042, 0x2085, 0x0044, 0x2089, 0x0046, 0x208d, 0x0048, 0x2091, 0x004a, 0x2095, 0x004c, 0x2099, 0x004e, 0x209d,
0x0050, 0x20a1, 0x0052, 0x20a5, 0x0054, 0x20a9, 0x0056, 0x20ad, 0x0058, 0x20b1, 0x005a, 0x20b5, 0x005c, 0x20b9, 0x005e, 0x20bd,
0x0060, 0x20c1, 0x0062, 0x20c5, 0x0064, 0x20c9, 0x0066, 0x20cd, 0x0068, 0x20d1, 0x006a, 0x20d5, 0x006c, 0x20d9, 0x006e, 0x20dd,
0x0070, 0x20e1, 0x0072, 0x20e5, 0x0074, 0x20e9, 0x0076, 0x20ed, 0x0078, 0x20f1, 0x007a, 0x20f5, 0x207c, 0x40f9, 0x20be, 0x417d,
0x0480, 0x2501, 0x0482, 0x2505, 0x0484, 0x2509, 0x0486, 0x250d, 0x0488, 0x2511, 0x048a, 0x2515, 0x048c, 0x2519, 0x048e, 0x251d,
0x0490, 0x2521, 0x0492, 0x2525, 0x0494, 0x2529, 0x0496, 0x252d, 0x0498, 0x2531, 0x049a, 0x2535, 0x049c, 0x2539, 0x049e, 0x253d,
0x04a0, 0x2541, 0x04a2, 0x2545, 0x04a4, 0x2549, 0x04a6, 0x254d, 0x04a8, 0x2551, 0x04aa, 0x2555, 0x04ac, 0x2559, 0x04ae, 0x255d,
0x04b0, 0x2561, 0x04b2, 0x2565, 0x04b4, 0x2569, 0x04b6, 0x256d, 0x04b8, 0x2571, 0x04ba, 0x2575, 0x04bc, 0x2579, 0x253e, 0x467d,
0x08c0, 0x2981, 0x08c2, 0x2985, 0x08c4, 0x2989, 0x08c6, 0x298d, 0x08c8, 0x2991, 0x08ca, 0x2995, 0x08cc, 0x2999, 0x08ce, 0x299d,
0x08d0, 0x29a1, 0x08d2, 0x29a5, 0x08d4, 0x29a9, 0x08d6, 0x29ad, 0x08d8, 0x29b1, 0x08da, 0x29b5, 0x08dc, 0x29b9, 0x08de, 0x29bd,
0x0ce0, 0x2dc1, 0x0ce2, 0x2dc5, 0x0ce4, 0x2dc9, 0x0ce6, 0x2dcd, 0x0ce8, 0x2dd1, 0x0cea, 0x2dd5, 0x0cec, 0x2dd9, 0x0cee, 0x2ddd,
0x10f0, 0x31e1, 0x10f2, 0x31e5, 0x10f4, 0x31e9, 0x10f6, 0x31ed, 0x20f8, 0x41f1, 0x20fa, 0x41f5, 0x257c, 0x46f9, 0x29be, 0x4b7d
};
/* hdlc_bitstuff_byte
* perform HDLC bitstuffing for one input byte (8 bits, LSB first)
* parameters:
* cin input byte
* ones number of trailing '1' bits in result before this step
* iwb pointer to output buffer structure
* (write semaphore must be held)
* return value:
* number of trailing '1' bits in result after this step
*/
static inline int hdlc_bitstuff_byte(struct isowbuf_t *iwb, unsigned char cin,
int ones)
{
u16 stuff;
int shiftinc, newones;
/* get stuffing information for input byte
* value: bit 9.. 0 = result bits
* bit 12..10 = number of trailing '1' bits in result
* bit 14..13 = number of bits added by stuffing
*/
stuff = stufftab[256 * ones + cin];
shiftinc = (stuff >> 13) & 3;
newones = (stuff >> 10) & 7;
stuff &= 0x3ff;
/* append stuffed byte to output stream */
isowbuf_putbits(iwb, stuff, 8 + shiftinc);
return newones;
}
/* hdlc_buildframe
* Perform HDLC framing with bitstuffing on a byte buffer
* The input buffer is regarded as a sequence of bits, starting with the least
* significant bit of the first byte and ending with the most significant bit
* of the last byte. A 16 bit FCS is appended as defined by RFC 1662.
* Whenever five consecutive '1' bits appear in the resulting bit sequence, a
* '0' bit is inserted after them.
* The resulting bit string and a closing flag pattern (PPP_FLAG, '01111110')
* are appended to the output buffer starting at the given bit position, which
* is assumed to already contain a leading flag.
* The output buffer must have sufficient length; count + count/5 + 6 bytes
* starting at *out are safe and are verified to be present.
* parameters:
* in input buffer
* count number of bytes in input buffer
* iwb pointer to output buffer structure
* (write semaphore must be held)
* return value:
* position of end of packet in output buffer on success,
* -EAGAIN if write semaphore busy or buffer full
*/
static inline int hdlc_buildframe(struct isowbuf_t *iwb,
unsigned char *in, int count)
{
int ones;
u16 fcs;
int end;
unsigned char c;
if (isowbuf_freebytes(iwb) < count + count / 5 + 6 ||
isowbuf_startwrite(iwb) < 0) {
gig_dbg(DEBUG_ISO, "%s: %d bytes free -> -EAGAIN",
__func__, isowbuf_freebytes(iwb));
return -EAGAIN;
}
dump_bytes(DEBUG_STREAM_DUMP, "snd data", in, count);
/* bitstuff and checksum input data */
fcs = PPP_INITFCS;
ones = 0;
while (count-- > 0) {
c = *in++;
ones = hdlc_bitstuff_byte(iwb, c, ones);
fcs = crc_ccitt_byte(fcs, c);
}
/* bitstuff and append FCS
* (complemented, least significant byte first) */
fcs ^= 0xffff;
ones = hdlc_bitstuff_byte(iwb, fcs & 0x00ff, ones);
ones = hdlc_bitstuff_byte(iwb, (fcs >> 8) & 0x00ff, ones);
/* put closing flag and repeat byte for flag idle */
isowbuf_putflag(iwb);
end = isowbuf_donewrite(iwb);
return end;
}
/* trans_buildframe
* Append a block of 'transparent' data to the output buffer,
* inverting the bytes.
* The output buffer must have sufficient length; count bytes
* starting at *out are safe and are verified to be present.
* parameters:
* in input buffer
* count number of bytes in input buffer
* iwb pointer to output buffer structure
* (write semaphore must be held)
* return value:
* position of end of packet in output buffer on success,
* -EAGAIN if write semaphore busy or buffer full
*/
static inline int trans_buildframe(struct isowbuf_t *iwb,
unsigned char *in, int count)
{
int write;
unsigned char c;
if (unlikely(count <= 0))
return iwb->write;
if (isowbuf_freebytes(iwb) < count ||
isowbuf_startwrite(iwb) < 0) {
gig_dbg(DEBUG_ISO, "can't put %d bytes", count);
return -EAGAIN;
}
gig_dbg(DEBUG_STREAM, "put %d bytes", count);
dump_bytes(DEBUG_STREAM_DUMP, "snd data", in, count);
write = iwb->write;
do {
c = bitrev8(*in++);
iwb->data[write++] = c;
write %= BAS_OUTBUFSIZE;
} while (--count > 0);
iwb->write = write;
iwb->idle = c;
return isowbuf_donewrite(iwb);
}
int gigaset_isoc_buildframe(struct bc_state *bcs, unsigned char *in, int len)
{
int result;
switch (bcs->proto2) {
case L2_HDLC:
result = hdlc_buildframe(bcs->hw.bas->isooutbuf, in, len);
gig_dbg(DEBUG_ISO, "%s: %d bytes HDLC -> %d",
__func__, len, result);
break;
default: /* assume transparent */
result = trans_buildframe(bcs->hw.bas->isooutbuf, in, len);
gig_dbg(DEBUG_ISO, "%s: %d bytes trans -> %d",
__func__, len, result);
}
return result;
}
/* hdlc_putbyte
* append byte c to current skb of B channel structure *bcs, updating fcs
*/
static inline void hdlc_putbyte(unsigned char c, struct bc_state *bcs)
{
bcs->rx_fcs = crc_ccitt_byte(bcs->rx_fcs, c);
if (bcs->rx_skb == NULL)
/* skipping */
return;
if (bcs->rx_skb->len >= bcs->rx_bufsize) {
dev_warn(bcs->cs->dev, "received oversized packet discarded\n");
bcs->hw.bas->giants++;
dev_kfree_skb_any(bcs->rx_skb);
bcs->rx_skb = NULL;
return;
}
*__skb_put(bcs->rx_skb, 1) = c;
}
/* hdlc_flush
* drop partial HDLC data packet
*/
static inline void hdlc_flush(struct bc_state *bcs)
{
/* clear skb or allocate new if not skipping */
if (bcs->rx_skb != NULL)
skb_trim(bcs->rx_skb, 0);
else
gigaset_new_rx_skb(bcs);
/* reset packet state */
bcs->rx_fcs = PPP_INITFCS;
}
/* hdlc_done
* process completed HDLC data packet
*/
static inline void hdlc_done(struct bc_state *bcs)
{
struct cardstate *cs = bcs->cs;
struct sk_buff *procskb;
unsigned int len;
if (unlikely(bcs->ignore)) {
bcs->ignore--;
hdlc_flush(bcs);
return;
}
procskb = bcs->rx_skb;
if (procskb == NULL) {
/* previous error */
gig_dbg(DEBUG_ISO, "%s: skb=NULL", __func__);
gigaset_isdn_rcv_err(bcs);
} else if (procskb->len < 2) {
dev_notice(cs->dev, "received short frame (%d octets)\n",
procskb->len);
bcs->hw.bas->runts++;
dev_kfree_skb_any(procskb);
gigaset_isdn_rcv_err(bcs);
} else if (bcs->rx_fcs != PPP_GOODFCS) {
dev_notice(cs->dev, "frame check error\n");
bcs->hw.bas->fcserrs++;
dev_kfree_skb_any(procskb);
gigaset_isdn_rcv_err(bcs);
} else {
len = procskb->len;
__skb_trim(procskb, len -= 2); /* subtract FCS */
gig_dbg(DEBUG_ISO, "%s: good frame (%d octets)", __func__, len);
dump_bytes(DEBUG_STREAM_DUMP,
"rcv data", procskb->data, len);
bcs->hw.bas->goodbytes += len;
gigaset_skb_rcvd(bcs, procskb);
}
gigaset_new_rx_skb(bcs);
bcs->rx_fcs = PPP_INITFCS;
}
/* hdlc_frag
* drop HDLC data packet with non-integral last byte
*/
static inline void hdlc_frag(struct bc_state *bcs, unsigned inbits)
{
if (unlikely(bcs->ignore)) {
bcs->ignore--;
hdlc_flush(bcs);
return;
}
dev_notice(bcs->cs->dev, "received partial byte (%d bits)\n", inbits);
bcs->hw.bas->alignerrs++;
gigaset_isdn_rcv_err(bcs);
__skb_trim(bcs->rx_skb, 0);
bcs->rx_fcs = PPP_INITFCS;
}
/* bit counts lookup table for HDLC bit unstuffing
* index: input byte
* value: bit 0..3 = number of consecutive '1' bits starting from LSB
* bit 4..6 = number of consecutive '1' bits starting from MSB
* (replacing 8 by 7 to make it fit; the algorithm won't care)
* bit 7 set if there are 5 or more "interior" consecutive '1' bits
*/
static const unsigned char bitcounts[256] = {
0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05,
0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x80, 0x06,
0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05,
0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x80, 0x81, 0x80, 0x07,
0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14,
0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x15,
0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14,
0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x90, 0x16,
0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x24,
0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x25,
0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x33, 0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x34,
0x40, 0x41, 0x40, 0x42, 0x40, 0x41, 0x40, 0x43, 0x50, 0x51, 0x50, 0x52, 0x60, 0x61, 0x70, 0x78
};
/* hdlc_unpack
* perform HDLC frame processing (bit unstuffing, flag detection, FCS
* calculation) on a sequence of received data bytes (8 bits each, LSB first)
* pass on successfully received, complete frames as SKBs via gigaset_skb_rcvd
* notify of errors via gigaset_isdn_rcv_err
* tally frames, errors etc. in BC structure counters
* parameters:
* src received data
* count number of received bytes
* bcs receiving B channel structure
*/
static inline void hdlc_unpack(unsigned char *src, unsigned count,
struct bc_state *bcs)
{
struct bas_bc_state *ubc = bcs->hw.bas;
int inputstate;
unsigned seqlen, inbyte, inbits;
/* load previous state:
* inputstate = set of flag bits:
* - INS_flag_hunt: no complete opening flag received since connection
* setup or last abort
* - INS_have_data: at least one complete data byte received since last
* flag
* seqlen = number of consecutive '1' bits in last 7 input stream bits
* (0..7)
* inbyte = accumulated partial data byte (if !INS_flag_hunt)
* inbits = number of valid bits in inbyte, starting at LSB (0..6)
*/
inputstate = bcs->inputstate;
seqlen = ubc->seqlen;
inbyte = ubc->inbyte;
inbits = ubc->inbits;
/* bit unstuffing a byte a time
* Take your time to understand this; it's straightforward but tedious.
* The "bitcounts" lookup table is used to speed up the counting of
* leading and trailing '1' bits.
*/
while (count--) {
unsigned char c = *src++;
unsigned char tabentry = bitcounts[c];
unsigned lead1 = tabentry & 0x0f;
unsigned trail1 = (tabentry >> 4) & 0x0f;
seqlen += lead1;
if (unlikely(inputstate & INS_flag_hunt)) {
if (c == PPP_FLAG) {
/* flag-in-one */
inputstate &= ~(INS_flag_hunt | INS_have_data);
inbyte = 0;
inbits = 0;
} else if (seqlen == 6 && trail1 != 7) {
/* flag completed & not followed by abort */
inputstate &= ~(INS_flag_hunt | INS_have_data);
inbyte = c >> (lead1 + 1);
inbits = 7 - lead1;
if (trail1 >= 8) {
/* interior stuffing:
* omitting the MSB handles most cases,
* correct the incorrectly handled
* cases individually */
inbits--;
switch (c) {
case 0xbe:
inbyte = 0x3f;
break;
}
}
}
/* else: continue flag-hunting */
} else if (likely(seqlen < 5 && trail1 < 7)) {
/* streamlined case: 8 data bits, no stuffing */
inbyte |= c << inbits;
hdlc_putbyte(inbyte & 0xff, bcs);
inputstate |= INS_have_data;
inbyte >>= 8;
/* inbits unchanged */
} else if (likely(seqlen == 6 && inbits == 7 - lead1 &&
trail1 + 1 == inbits &&
!(inputstate & INS_have_data))) {
/* streamlined case: flag idle - state unchanged */
} else if (unlikely(seqlen > 6)) {
/* abort sequence */
ubc->aborts++;
hdlc_flush(bcs);
inputstate |= INS_flag_hunt;
} else if (seqlen == 6) {
/* closing flag, including (6 - lead1) '1's
* and one '0' from inbits */
if (inbits > 7 - lead1) {
hdlc_frag(bcs, inbits + lead1 - 7);
inputstate &= ~INS_have_data;
} else {
if (inbits < 7 - lead1)
ubc->stolen0s++;
if (inputstate & INS_have_data) {
hdlc_done(bcs);
inputstate &= ~INS_have_data;
}
}
if (c == PPP_FLAG) {
/* complete flag, LSB overlaps preceding flag */
ubc->shared0s++;
inbits = 0;
inbyte = 0;
} else if (trail1 != 7) {
/* remaining bits */
inbyte = c >> (lead1 + 1);
inbits = 7 - lead1;
if (trail1 >= 8) {
/* interior stuffing:
* omitting the MSB handles most cases,
* correct the incorrectly handled
* cases individually */
inbits--;
switch (c) {
case 0xbe:
inbyte = 0x3f;
break;
}
}
} else {
/* abort sequence follows,
* skb already empty anyway */
ubc->aborts++;
inputstate |= INS_flag_hunt;
}
} else { /* (seqlen < 6) && (seqlen == 5 || trail1 >= 7) */
if (c == PPP_FLAG) {
/* complete flag */
if (seqlen == 5)
ubc->stolen0s++;
if (inbits) {
hdlc_frag(bcs, inbits);
inbits = 0;
inbyte = 0;
} else if (inputstate & INS_have_data)
hdlc_done(bcs);
inputstate &= ~INS_have_data;
} else if (trail1 == 7) {
/* abort sequence */
ubc->aborts++;
hdlc_flush(bcs);
inputstate |= INS_flag_hunt;
} else {
/* stuffed data */
if (trail1 < 7) { /* => seqlen == 5 */
/* stuff bit at position lead1,
* no interior stuffing */
unsigned char mask = (1 << lead1) - 1;
c = (c & mask) | ((c & ~mask) >> 1);
inbyte |= c << inbits;
inbits += 7;
} else if (seqlen < 5) { /* trail1 >= 8 */
/* interior stuffing:
* omitting the MSB handles most cases,
* correct the incorrectly handled
* cases individually */
switch (c) {
case 0xbe:
c = 0x7e;
break;
}
inbyte |= c << inbits;
inbits += 7;
} else { /* seqlen == 5 && trail1 >= 8 */
/* stuff bit at lead1 *and* interior
* stuffing -- unstuff individually */
switch (c) {
case 0x7d:
c = 0x3f;
break;
case 0xbe:
c = 0x3f;
break;
case 0x3e:
c = 0x1f;
break;
case 0x7c:
c = 0x3e;
break;
}
inbyte |= c << inbits;
inbits += 6;
}
if (inbits >= 8) {
inbits -= 8;
hdlc_putbyte(inbyte & 0xff, bcs);
inputstate |= INS_have_data;
inbyte >>= 8;
}
}
}
seqlen = trail1 & 7;
}
/* save new state */
bcs->inputstate = inputstate;
ubc->seqlen = seqlen;
ubc->inbyte = inbyte;
ubc->inbits = inbits;
}
/* trans_receive
* pass on received USB frame transparently as SKB via gigaset_skb_rcvd
* invert bytes
* tally frames, errors etc. in BC structure counters
* parameters:
* src received data
* count number of received bytes
* bcs receiving B channel structure
*/
static inline void trans_receive(unsigned char *src, unsigned count,
struct bc_state *bcs)
{
struct sk_buff *skb;
int dobytes;
unsigned char *dst;
if (unlikely(bcs->ignore)) {
bcs->ignore--;
return;
}
skb = bcs->rx_skb;
if (skb == NULL) {
skb = gigaset_new_rx_skb(bcs);
if (skb == NULL)
return;
}
dobytes = bcs->rx_bufsize - skb->len;
while (count > 0) {
dst = skb_put(skb, count < dobytes ? count : dobytes);
while (count > 0 && dobytes > 0) {
*dst++ = bitrev8(*src++);
count--;
dobytes--;
}
if (dobytes == 0) {
dump_bytes(DEBUG_STREAM_DUMP,
"rcv data", skb->data, skb->len);
bcs->hw.bas->goodbytes += skb->len;
gigaset_skb_rcvd(bcs, skb);
skb = gigaset_new_rx_skb(bcs);
if (skb == NULL)
return;
dobytes = bcs->rx_bufsize;
}
}
}
void gigaset_isoc_receive(unsigned char *src, unsigned count,
struct bc_state *bcs)
{
switch (bcs->proto2) {
case L2_HDLC:
hdlc_unpack(src, count, bcs);
break;
default: /* assume transparent */
trans_receive(src, count, bcs);
}
}
/* == data input =========================================================== */
/* process a block of received bytes in command mode (mstate != MS_LOCKED)
* Append received bytes to the command response buffer and forward them
* line by line to the response handler.
* Note: Received lines may be terminated by CR, LF, or CR LF, which will be
* removed before passing the line to the response handler.
*/
static void cmd_loop(unsigned char *src, int numbytes, struct inbuf_t *inbuf)
{
struct cardstate *cs = inbuf->cs;
unsigned cbytes = cs->cbytes;
unsigned char c;
while (numbytes--) {
c = *src++;
switch (c) {
case '\n':
if (cbytes == 0 && cs->respdata[0] == '\r') {
/* collapse LF with preceding CR */
cs->respdata[0] = 0;
break;
}
/* --v-- fall through --v-- */
case '\r':
/* end of message line, pass to response handler */
if (cbytes >= MAX_RESP_SIZE) {
dev_warn(cs->dev, "response too large (%d)\n",
cbytes);
cbytes = MAX_RESP_SIZE;
}
cs->cbytes = cbytes;
gigaset_dbg_buffer(DEBUG_TRANSCMD, "received response",
cbytes, cs->respdata);
gigaset_handle_modem_response(cs);
cbytes = 0;
/* store EOL byte for CRLF collapsing */
cs->respdata[0] = c;
break;
default:
/* append to line buffer if possible */
if (cbytes < MAX_RESP_SIZE)
cs->respdata[cbytes] = c;
cbytes++;
}
}
/* save state */
cs->cbytes = cbytes;
}
/* process a block of data received through the control channel
*/
void gigaset_isoc_input(struct inbuf_t *inbuf)
{
struct cardstate *cs = inbuf->cs;
unsigned tail, head, numbytes;
unsigned char *src;
head = inbuf->head;
while (head != (tail = inbuf->tail)) {
gig_dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail);
if (head > tail)
tail = RBUFSIZE;
src = inbuf->data + head;
numbytes = tail - head;
gig_dbg(DEBUG_INTR, "processing %u bytes", numbytes);
if (cs->mstate == MS_LOCKED) {
gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response",
numbytes, src);
gigaset_if_receive(inbuf->cs, src, numbytes);
} else {
cmd_loop(src, numbytes, inbuf);
}
head += numbytes;
if (head == RBUFSIZE)
head = 0;
gig_dbg(DEBUG_INTR, "setting head to %u", head);
inbuf->head = head;
}
}
/* == data output ========================================================== */
/**
* gigaset_isoc_send_skb() - queue an skb for sending
* @bcs: B channel descriptor structure.
* @skb: data to send.
*
* Called by LL to queue an skb for sending, and start transmission if
* necessary.
* Once the payload data has been transmitted completely, gigaset_skb_sent()
* will be called with the skb's link layer header preserved.
*
* Return value:
* number of bytes accepted for sending (skb->len) if ok,
* error code < 0 (eg. -ENODEV) on error
*/
int gigaset_isoc_send_skb(struct bc_state *bcs, struct sk_buff *skb)
{
int len = skb->len;
unsigned long flags;
spin_lock_irqsave(&bcs->cs->lock, flags);
if (!bcs->cs->connected) {
spin_unlock_irqrestore(&bcs->cs->lock, flags);
return -ENODEV;
}
skb_queue_tail(&bcs->squeue, skb);
gig_dbg(DEBUG_ISO, "%s: skb queued, qlen=%d",
__func__, skb_queue_len(&bcs->squeue));
/* tasklet submits URB if necessary */
tasklet_schedule(&bcs->hw.bas->sent_tasklet);
spin_unlock_irqrestore(&bcs->cs->lock, flags);
return len; /* ok so far */
}
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