diff options
Diffstat (limited to 'drivers/isdn')
| -rw-r--r-- | drivers/isdn/gigaset/isocdata.c | 1009 |
1 files changed, 1009 insertions, 0 deletions
diff --git a/drivers/isdn/gigaset/isocdata.c b/drivers/isdn/gigaset/isocdata.c new file mode 100644 index 00000000000..5744eb91b31 --- /dev/null +++ b/drivers/isdn/gigaset/isocdata.c @@ -0,0 +1,1009 @@ +/* + * 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. + * ===================================================================== + * ToDo: ... + * ===================================================================== + * Version: $Id: isocdata.c,v 1.2.2.5 2005/11/13 23:05:19 hjlipp Exp $ + * ===================================================================== + */ + +#include "gigaset.h" +#include <linux/crc-ccitt.h> + +/* access methods for isowbuf_t */ +/* ============================ */ + +/* initialize buffer structure + */ +void gigaset_isowbuf_init(struct isowbuf_t *iwb, unsigned char idle) +{ + atomic_set(&iwb->read, 0); + atomic_set(&iwb->nextread, 0); + atomic_set(&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 = atomic_read(&iwb->read); + write = atomic_read(&iwb->write); + if ((freebytes = read - write) > 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; + } +} + +/* compare two offsets within the buffer + * The buffer is seen as circular, with the read position as start + * returns -1/0/1 if position a </=/> position b without crossing 'read' + */ +static inline int isowbuf_poscmp(struct isowbuf_t *iwb, int a, int b) +{ + int read; + if (a == b) + return 0; + read = atomic_read(&iwb->read); + if (a < b) { + if (a < read && read <= b) + return +1; + else + return -1; + } else { + if (b < read && read <= a) + return -1; + else + return +1; + } +} + +/* start writing + * acquire the write semaphore + * return true if acquired, false if busy + */ +static inline int isowbuf_startwrite(struct isowbuf_t *iwb) +{ + if (!atomic_dec_and_test(&iwb->writesem)) { + atomic_inc(&iwb->writesem); + dbg(DEBUG_ISO, + "%s: couldn't acquire iso write semaphore", __func__); + return 0; + } +#ifdef CONFIG_GIGASET_DEBUG + dbg(DEBUG_ISO, + "%s: acquired iso write semaphore, data[write]=%02x, nbits=%d", + __func__, iwb->data[atomic_read(&iwb->write)], iwb->wbits); +#endif + return 1; +} + +/* finish writing + * release the write semaphore and update the maximum buffer fill level + * returns the current write position + */ +static inline int isowbuf_donewrite(struct isowbuf_t *iwb) +{ + int write = atomic_read(&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 = atomic_read(&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; + atomic_set(&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 = atomic_read(&iwb->write); + iwb->idle = iwb->data[write]; + 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 = atomic_read(&iwb->nextread); + write = atomic_read(&iwb->write); + if (likely(read == write)) { + //dbg(DEBUG_STREAM, "%s: send buffer empty", __func__); + /* return idle frame */ + return read < BAS_OUTBUFPAD ? + BAS_OUTBUFSIZE : read - BAS_OUTBUFPAD; + } + + limit = read + size; + 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)) { + err("invalid size %d", size); + return -EINVAL; + } + src = atomic_read(&iwb->read); + if (unlikely(limit > BAS_OUTBUFSIZE + BAS_OUTBUFPAD || + (read < src && limit >= src))) { + err("isoc write buffer frame reservation violated"); + return -EFAULT; + } +#endif + + if (read < write) { + /* no wraparound in valid data */ + if (limit >= write) { + /* append idle frame */ + if (!isowbuf_startwrite(iwb)) + return -EBUSY; + /* write position could have changed */ + if (limit >= (write = atomic_read(&iwb->write))) { + pbyte = iwb->data[write]; /* save partial byte */ + limit = write + BAS_OUTBUFPAD; + 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; + } + dbg(DEBUG_STREAM, "%s: restoring %02x at %d", + __func__, pbyte, limit); + iwb->data[limit] = pbyte; /* restore partial byte */ + atomic_set(&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; + } + } + atomic_set(&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]; + static const char hexdigit[] = "0123456789abcdef"; + int i = 0; + IFNULLRET(tag); + IFNULLRET(bytes); + while (count-- > 0) { + if (i > sizeof(dbgline) - 4) { + dbgline[i] = '\0'; + dbg(level, "%s:%s", tag, dbgline); + i = 0; + } + c = *bytes++; + dbgline[i] = (i && !(i % 12)) ? '-' : ' '; + i++; + dbgline[i++] = hexdigit[(c >> 4) & 0x0f]; + dbgline[i++] = hexdigit[c & 0x0f]; + } + dbgline[i] = '\0'; + 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 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)) { + dbg(DEBUG_ISO, "%s: %d bytes free -> -EAGAIN", + __func__, isowbuf_freebytes(iwb)); + return -EAGAIN; + } + + dump_bytes(DEBUG_STREAM, "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); + dump_bytes(DEBUG_STREAM_DUMP, "isowbuf", iwb->data, end + 1); + 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 atomic_read(&iwb->write); /* better ideas? */ + + if (isowbuf_freebytes(iwb) < count || + !isowbuf_startwrite(iwb)) { + dbg(DEBUG_ISO, "can't put %d bytes", count); + return -EAGAIN; + } + + dbg(DEBUG_STREAM, "put %d bytes", count); + write = atomic_read(&iwb->write); + do { + c = gigaset_invtab[*in++]; + iwb->data[write++] = c; + write %= BAS_OUTBUFSIZE; + } while (--count > 0); + atomic_set(&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 ISDN_PROTO_L2_HDLC: + result = hdlc_buildframe(bcs->hw.bas->isooutbuf, in, len); + dbg(DEBUG_ISO, "%s: %d bytes HDLC -> %d", __func__, len, result); + break; + default: /* assume transparent */ + result = trans_buildframe(bcs->hw.bas->isooutbuf, in, len); + 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->fcs = crc_ccitt_byte(bcs->fcs, c); + if (unlikely(bcs->skb == NULL)) { + /* skipping */ + return; + } + if (unlikely(bcs->skb->len == SBUFSIZE)) { + warn("received oversized packet discarded"); + bcs->hw.bas->giants++; + dev_kfree_skb_any(bcs->skb); + bcs->skb = NULL; + return; + } + *gigaset_skb_put_quick(bcs->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 (likely(bcs->skb != NULL)) + skb_trim(bcs->skb, 0); + else if (!bcs->ignore) { + if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL) + skb_reserve(bcs->skb, HW_HDR_LEN); + else + err("could not allocate skb"); + } + + /* reset packet state */ + bcs->fcs = PPP_INITFCS; +} + +/* hdlc_done + * process completed HDLC data packet + */ +static inline void hdlc_done(struct bc_state *bcs) +{ + struct sk_buff *procskb; + + if (unlikely(bcs->ignore)) { + bcs->ignore--; + hdlc_flush(bcs); + return; + } + + if ((procskb = bcs->skb) == NULL) { + /* previous error */ + dbg(DEBUG_ISO, "%s: skb=NULL", __func__); + gigaset_rcv_error(NULL, bcs->cs, bcs); + } else if (procskb->len < 2) { + notice("received short frame (%d octets)", procskb->len); + bcs->hw.bas->runts++; + gigaset_rcv_error(procskb, bcs->cs, bcs); + } else if (bcs->fcs != PPP_GOODFCS) { + notice("frame check error (0x%04x)", bcs->fcs); + bcs->hw.bas->fcserrs++; + gigaset_rcv_error(procskb, bcs->cs, bcs); + } else { + procskb->len -= 2; /* subtract FCS */ + procskb->tail -= 2; + dbg(DEBUG_ISO, + "%s: good frame (%d octets)", __func__, procskb->len); + dump_bytes(DEBUG_STREAM, + "rcv data", procskb->data, procskb->len); + bcs->hw.bas->goodbytes += procskb->len; + gigaset_rcv_skb(procskb, bcs->cs, bcs); + } + + if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL) + skb_reserve(bcs->skb, HW_HDR_LEN); + else + err("could not allocate skb"); + bcs->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; + } + + notice("received partial byte (%d bits)", inbits); + bcs->hw.bas->alignerrs++; + gigaset_rcv_error(bcs->skb, bcs->cs, bcs); + + if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL) + skb_reserve(bcs->skb, HW_HDR_LEN); + else + err("could not allocate skb"); + bcs->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 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_rcv_skb + * notify of errors via gigaset_rcv_error + * 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; + int inputstate; + unsigned seqlen, inbyte, inbits; + + IFNULLRET(bcs); + ubc = bcs->hw.bas; + IFNULLRET(ubc); + + /* 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 */ + inbits--; + /* correct the incorrectly handled cases individually */ + 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 */ + inbits--; + /* correct the incorrectly handled cases individually */ + 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 */ + switch (c) { /* unstuff individually */ + 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_rcv_skb + * 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--; + hdlc_flush(bcs); + return; + } + if (unlikely((skb = bcs->skb) == NULL)) { + bcs->skb = skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN); + if (!skb) { + err("could not allocate skb"); + return; + } + skb_reserve(skb, HW_HDR_LEN); + } + bcs->hw.bas->goodbytes += skb->len; + dobytes = TRANSBUFSIZE - skb->len; + while (count > 0) { + dst = skb_put(skb, count < dobytes ? count : dobytes); + while (count > 0 && dobytes > 0) { + *dst++ = gigaset_invtab[*src++]; + count--; + dobytes--; + } + if (dobytes == 0) { + gigaset_rcv_skb(skb, bcs->cs, bcs); + bcs->skb = skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN); + if (!skb) { + err("could not allocate skb"); + return; + } + skb_reserve(bcs->skb, HW_HDR_LEN); + dobytes = TRANSBUFSIZE; + } + } +} + +void gigaset_isoc_receive(unsigned char *src, unsigned count, struct bc_state *bcs) +{ + switch (bcs->proto2) { + case ISDN_PROTO_L2_HDLC: + hdlc_unpack(src, count, bcs); + break; + default: /* assume transparent */ + trans_receive(src, count, bcs); + } +} + +/* == data input =========================================================== */ + +static void cmd_loop(unsigned char *src, int numbytes, struct inbuf_t *inbuf) +{ + struct cardstate *cs = inbuf->cs; + unsigned cbytes = cs->cbytes; + + while (numbytes--) { + /* copy next character, check for end of line */ + switch (cs->respdata[cbytes] = *src++) { + case '\r': + case '\n': + /* end of line */ + dbg(DEBUG_TRANSCMD, "%s: End of Command (%d Bytes)", + __func__, cbytes); + cs->cbytes = cbytes; + gigaset_handle_modem_response(cs); + cbytes = 0; + break; + default: + /* advance in line buffer, checking for overflow */ + if (cbytes < MAX_RESP_SIZE - 1) + cbytes++; + else + warn("response too large"); + } + } + + /* 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 = atomic_read(&inbuf->head); + while (head != (tail = atomic_read(&inbuf->tail))) { + dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail); + if (head > tail) + tail = RBUFSIZE; + src = inbuf->data + head; + numbytes = tail - head; + dbg(DEBUG_INTR, "processing %u bytes", numbytes); + + if (atomic_read(&cs->mstate) == MS_LOCKED) { + gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response", + numbytes, src, 0); + gigaset_if_receive(inbuf->cs, src, numbytes); + } else { + gigaset_dbg_buffer(DEBUG_CMD, "received response", + numbytes, src, 0); + cmd_loop(src, numbytes, inbuf); + } + + head += numbytes; + if (head == RBUFSIZE) + head = 0; + dbg(DEBUG_INTR, "setting head to %u", head); + atomic_set(&inbuf->head, head); + } +} + + +/* == data output ========================================================== */ + +/* gigaset_send_skb + * called by common.c to queue an skb for sending + * and start transmission if necessary + * parameters: + * B Channel control structure + * skb + * return value: + * number of bytes accepted for sending + * (skb->len if ok, 0 if out of buffer space) + * or error code (< 0, eg. -EINVAL) + */ +int gigaset_isoc_send_skb(struct bc_state *bcs, struct sk_buff *skb) +{ + int len; + + IFNULLRETVAL(bcs, -EFAULT); + IFNULLRETVAL(skb, -EFAULT); + len = skb->len; + + skb_queue_tail(&bcs->squeue, skb); + 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); + + return len; /* ok so far */ +} |