2 * Common data handling layer for bas_gigaset
4 * Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>,
5 * Hansjoerg Lipp <hjlipp@web.de>.
7 * =====================================================================
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 * =====================================================================
16 #include <linux/crc-ccitt.h>
18 /* access methods for isowbuf_t */
19 /* ============================ */
21 /* initialize buffer structure
23 void gigaset_isowbuf_init(struct isowbuf_t *iwb, unsigned char idle)
25 atomic_set(&iwb->read, 0);
26 atomic_set(&iwb->nextread, 0);
27 atomic_set(&iwb->write, 0);
28 atomic_set(&iwb->writesem, 1);
31 memset(iwb->data + BAS_OUTBUFSIZE, idle, BAS_OUTBUFPAD);
34 /* compute number of bytes which can be appended to buffer
35 * so that there is still room to append a maximum frame of flags
37 static inline int isowbuf_freebytes(struct isowbuf_t *iwb)
39 int read, write, freebytes;
41 read = atomic_read(&iwb->read);
42 write = atomic_read(&iwb->write);
43 if ((freebytes = read - write) > 0) {
44 /* no wraparound: need padding space within regular area */
45 return freebytes - BAS_OUTBUFPAD;
46 } else if (read < BAS_OUTBUFPAD) {
47 /* wraparound: can use space up to end of regular area */
48 return BAS_OUTBUFSIZE - write;
50 /* following the wraparound yields more space */
51 return freebytes + BAS_OUTBUFSIZE - BAS_OUTBUFPAD;
55 /* compare two offsets within the buffer
56 * The buffer is seen as circular, with the read position as start
57 * returns -1/0/1 if position a </=/> position b without crossing 'read'
59 static inline int isowbuf_poscmp(struct isowbuf_t *iwb, int a, int b)
64 read = atomic_read(&iwb->read);
66 if (a < read && read <= b)
71 if (b < read && read <= a)
79 * acquire the write semaphore
80 * return true if acquired, false if busy
82 static inline int isowbuf_startwrite(struct isowbuf_t *iwb)
84 if (!atomic_dec_and_test(&iwb->writesem)) {
85 atomic_inc(&iwb->writesem);
87 "%s: couldn't acquire iso write semaphore", __func__);
90 #ifdef CONFIG_GIGASET_DEBUG
92 "%s: acquired iso write semaphore, data[write]=%02x, nbits=%d",
93 __func__, iwb->data[atomic_read(&iwb->write)], iwb->wbits);
99 * release the write semaphore and update the maximum buffer fill level
100 * returns the current write position
102 static inline int isowbuf_donewrite(struct isowbuf_t *iwb)
104 int write = atomic_read(&iwb->write);
105 atomic_inc(&iwb->writesem);
109 /* append bits to buffer without any checks
110 * - data contains bits to append, starting at LSB
111 * - nbits is number of bits to append (0..24)
112 * must be called with the write semaphore held
113 * If more than nbits bits are set in data, the extraneous bits are set in the
114 * buffer too, but the write position is only advanced by nbits.
116 static inline void isowbuf_putbits(struct isowbuf_t *iwb, u32 data, int nbits)
118 int write = atomic_read(&iwb->write);
120 data |= iwb->data[write];
123 iwb->data[write++] = data & 0xff;
124 write %= BAS_OUTBUFSIZE;
129 iwb->data[write] = data & 0xff;
130 atomic_set(&iwb->write, write);
133 /* put final flag on HDLC bitstream
134 * also sets the idle fill byte to the correspondingly shifted flag pattern
135 * must be called with the write semaphore held
137 static inline void isowbuf_putflag(struct isowbuf_t *iwb)
141 /* add two flags, thus reliably covering one byte */
142 isowbuf_putbits(iwb, 0x7e7e, 8);
143 /* recover the idle flag byte */
144 write = atomic_read(&iwb->write);
145 iwb->idle = iwb->data[write];
146 dbg(DEBUG_ISO, "idle fill byte %02x", iwb->idle);
147 /* mask extraneous bits in buffer */
148 iwb->data[write] &= (1 << iwb->wbits) - 1;
151 /* retrieve a block of bytes for sending
152 * The requested number of bytes is provided as a contiguous block.
153 * If necessary, the frame is filled to the requested number of bytes
154 * with the idle value.
155 * returns offset to frame, < 0 on busy or error
157 int gigaset_isowbuf_getbytes(struct isowbuf_t *iwb, int size)
159 int read, write, limit, src, dst;
162 read = atomic_read(&iwb->nextread);
163 write = atomic_read(&iwb->write);
164 if (likely(read == write)) {
165 //dbg(DEBUG_STREAM, "%s: send buffer empty", __func__);
166 /* return idle frame */
167 return read < BAS_OUTBUFPAD ?
168 BAS_OUTBUFSIZE : read - BAS_OUTBUFPAD;
173 "%s: read=%d write=%d limit=%d", __func__, read, write, limit);
174 #ifdef CONFIG_GIGASET_DEBUG
175 if (unlikely(size < 0 || size > BAS_OUTBUFPAD)) {
176 err("invalid size %d", size);
179 src = atomic_read(&iwb->read);
180 if (unlikely(limit > BAS_OUTBUFSIZE + BAS_OUTBUFPAD ||
181 (read < src && limit >= src))) {
182 err("isoc write buffer frame reservation violated");
188 /* no wraparound in valid data */
189 if (limit >= write) {
190 /* append idle frame */
191 if (!isowbuf_startwrite(iwb))
193 /* write position could have changed */
194 if (limit >= (write = atomic_read(&iwb->write))) {
195 pbyte = iwb->data[write]; /* save
197 limit = write + BAS_OUTBUFPAD;
199 "%s: filling %d->%d with %02x",
200 __func__, write, limit, iwb->idle);
201 if (write + BAS_OUTBUFPAD < BAS_OUTBUFSIZE)
202 memset(iwb->data + write, iwb->idle,
205 /* wraparound, fill entire pad area */
206 memset(iwb->data + write, iwb->idle,
207 BAS_OUTBUFSIZE + BAS_OUTBUFPAD
211 dbg(DEBUG_STREAM, "%s: restoring %02x at %d",
212 __func__, pbyte, limit);
213 iwb->data[limit] = pbyte; /* restore
215 atomic_set(&iwb->write, limit);
217 isowbuf_donewrite(iwb);
220 /* valid data wraparound */
221 if (limit >= BAS_OUTBUFSIZE) {
222 /* copy wrapped part into pad area */
224 dst = BAS_OUTBUFSIZE;
225 while (dst < limit && src < write)
226 iwb->data[dst++] = iwb->data[src++];
228 /* fill pad area with idle byte */
229 memset(iwb->data + dst, iwb->idle,
230 BAS_OUTBUFSIZE + BAS_OUTBUFPAD - dst);
235 atomic_set(&iwb->nextread, limit);
240 * write hex bytes to syslog for debugging
242 static inline void dump_bytes(enum debuglevel level, const char *tag,
243 unsigned char *bytes, int count)
245 #ifdef CONFIG_GIGASET_DEBUG
247 static char dbgline[3 * 32 + 1];
248 static const char hexdigit[] = "0123456789abcdef";
252 while (count-- > 0) {
253 if (i > sizeof(dbgline) - 4) {
255 dbg(level, "%s:%s", tag, dbgline);
259 dbgline[i] = (i && !(i % 12)) ? '-' : ' ';
261 dbgline[i++] = hexdigit[(c >> 4) & 0x0f];
262 dbgline[i++] = hexdigit[c & 0x0f];
265 dbg(level, "%s:%s", tag, dbgline);
269 /*============================================================================*/
271 /* bytewise HDLC bitstuffing via table lookup
272 * lookup table: 5 subtables for 0..4 preceding consecutive '1' bits
273 * index: 256*(number of preceding '1' bits) + (next byte to stuff)
274 * value: bit 9.. 0 = result bits
275 * bit 12..10 = number of trailing '1' bits in result
276 * bit 14..13 = number of bits added by stuffing
278 static u16 stufftab[5 * 256] = {
280 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
281 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x201f,
282 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
283 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x205f,
284 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
285 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x209f,
286 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
287 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20df,
288 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x048f,
289 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x251f,
290 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x04af,
291 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x255f,
292 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x08cf,
293 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x299f,
294 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x0cef,
295 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x2ddf,
298 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x200f,
299 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x202f,
300 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x204f,
301 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x206f,
302 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x208f,
303 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20af,
304 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20cf,
305 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20ef,
306 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x250f,
307 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x252f,
308 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x254f,
309 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x256f,
310 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x298f,
311 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29af,
312 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dcf,
313 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x31ef,
316 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x2007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x2017,
317 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x2027, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x2037,
318 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x2047, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x2057,
319 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x2067, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x2077,
320 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x2087, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x2097,
321 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x20a7, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20b7,
322 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x20c7, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20d7,
323 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x20e7, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20f7,
324 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x2507, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x2517,
325 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x2527, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x2537,
326 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x2547, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x2557,
327 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x2567, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x2577,
328 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x2987, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x2997,
329 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x29a7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29b7,
330 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dc7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dd7,
331 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x31e7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x41f7,
334 0x0000, 0x0001, 0x0002, 0x2003, 0x0004, 0x0005, 0x0006, 0x200b, 0x0008, 0x0009, 0x000a, 0x2013, 0x000c, 0x000d, 0x000e, 0x201b,
335 0x0010, 0x0011, 0x0012, 0x2023, 0x0014, 0x0015, 0x0016, 0x202b, 0x0018, 0x0019, 0x001a, 0x2033, 0x001c, 0x001d, 0x001e, 0x203b,
336 0x0020, 0x0021, 0x0022, 0x2043, 0x0024, 0x0025, 0x0026, 0x204b, 0x0028, 0x0029, 0x002a, 0x2053, 0x002c, 0x002d, 0x002e, 0x205b,
337 0x0030, 0x0031, 0x0032, 0x2063, 0x0034, 0x0035, 0x0036, 0x206b, 0x0038, 0x0039, 0x003a, 0x2073, 0x003c, 0x003d, 0x203e, 0x207b,
338 0x0040, 0x0041, 0x0042, 0x2083, 0x0044, 0x0045, 0x0046, 0x208b, 0x0048, 0x0049, 0x004a, 0x2093, 0x004c, 0x004d, 0x004e, 0x209b,
339 0x0050, 0x0051, 0x0052, 0x20a3, 0x0054, 0x0055, 0x0056, 0x20ab, 0x0058, 0x0059, 0x005a, 0x20b3, 0x005c, 0x005d, 0x005e, 0x20bb,
340 0x0060, 0x0061, 0x0062, 0x20c3, 0x0064, 0x0065, 0x0066, 0x20cb, 0x0068, 0x0069, 0x006a, 0x20d3, 0x006c, 0x006d, 0x006e, 0x20db,
341 0x0070, 0x0071, 0x0072, 0x20e3, 0x0074, 0x0075, 0x0076, 0x20eb, 0x0078, 0x0079, 0x007a, 0x20f3, 0x207c, 0x207d, 0x20be, 0x40fb,
342 0x0480, 0x0481, 0x0482, 0x2503, 0x0484, 0x0485, 0x0486, 0x250b, 0x0488, 0x0489, 0x048a, 0x2513, 0x048c, 0x048d, 0x048e, 0x251b,
343 0x0490, 0x0491, 0x0492, 0x2523, 0x0494, 0x0495, 0x0496, 0x252b, 0x0498, 0x0499, 0x049a, 0x2533, 0x049c, 0x049d, 0x049e, 0x253b,
344 0x04a0, 0x04a1, 0x04a2, 0x2543, 0x04a4, 0x04a5, 0x04a6, 0x254b, 0x04a8, 0x04a9, 0x04aa, 0x2553, 0x04ac, 0x04ad, 0x04ae, 0x255b,
345 0x04b0, 0x04b1, 0x04b2, 0x2563, 0x04b4, 0x04b5, 0x04b6, 0x256b, 0x04b8, 0x04b9, 0x04ba, 0x2573, 0x04bc, 0x04bd, 0x253e, 0x257b,
346 0x08c0, 0x08c1, 0x08c2, 0x2983, 0x08c4, 0x08c5, 0x08c6, 0x298b, 0x08c8, 0x08c9, 0x08ca, 0x2993, 0x08cc, 0x08cd, 0x08ce, 0x299b,
347 0x08d0, 0x08d1, 0x08d2, 0x29a3, 0x08d4, 0x08d5, 0x08d6, 0x29ab, 0x08d8, 0x08d9, 0x08da, 0x29b3, 0x08dc, 0x08dd, 0x08de, 0x29bb,
348 0x0ce0, 0x0ce1, 0x0ce2, 0x2dc3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dcb, 0x0ce8, 0x0ce9, 0x0cea, 0x2dd3, 0x0cec, 0x0ced, 0x0cee, 0x2ddb,
349 0x10f0, 0x10f1, 0x10f2, 0x31e3, 0x10f4, 0x10f5, 0x10f6, 0x31eb, 0x20f8, 0x20f9, 0x20fa, 0x41f3, 0x257c, 0x257d, 0x29be, 0x46fb,
352 0x0000, 0x2001, 0x0002, 0x2005, 0x0004, 0x2009, 0x0006, 0x200d, 0x0008, 0x2011, 0x000a, 0x2015, 0x000c, 0x2019, 0x000e, 0x201d,
353 0x0010, 0x2021, 0x0012, 0x2025, 0x0014, 0x2029, 0x0016, 0x202d, 0x0018, 0x2031, 0x001a, 0x2035, 0x001c, 0x2039, 0x001e, 0x203d,
354 0x0020, 0x2041, 0x0022, 0x2045, 0x0024, 0x2049, 0x0026, 0x204d, 0x0028, 0x2051, 0x002a, 0x2055, 0x002c, 0x2059, 0x002e, 0x205d,
355 0x0030, 0x2061, 0x0032, 0x2065, 0x0034, 0x2069, 0x0036, 0x206d, 0x0038, 0x2071, 0x003a, 0x2075, 0x003c, 0x2079, 0x203e, 0x407d,
356 0x0040, 0x2081, 0x0042, 0x2085, 0x0044, 0x2089, 0x0046, 0x208d, 0x0048, 0x2091, 0x004a, 0x2095, 0x004c, 0x2099, 0x004e, 0x209d,
357 0x0050, 0x20a1, 0x0052, 0x20a5, 0x0054, 0x20a9, 0x0056, 0x20ad, 0x0058, 0x20b1, 0x005a, 0x20b5, 0x005c, 0x20b9, 0x005e, 0x20bd,
358 0x0060, 0x20c1, 0x0062, 0x20c5, 0x0064, 0x20c9, 0x0066, 0x20cd, 0x0068, 0x20d1, 0x006a, 0x20d5, 0x006c, 0x20d9, 0x006e, 0x20dd,
359 0x0070, 0x20e1, 0x0072, 0x20e5, 0x0074, 0x20e9, 0x0076, 0x20ed, 0x0078, 0x20f1, 0x007a, 0x20f5, 0x207c, 0x40f9, 0x20be, 0x417d,
360 0x0480, 0x2501, 0x0482, 0x2505, 0x0484, 0x2509, 0x0486, 0x250d, 0x0488, 0x2511, 0x048a, 0x2515, 0x048c, 0x2519, 0x048e, 0x251d,
361 0x0490, 0x2521, 0x0492, 0x2525, 0x0494, 0x2529, 0x0496, 0x252d, 0x0498, 0x2531, 0x049a, 0x2535, 0x049c, 0x2539, 0x049e, 0x253d,
362 0x04a0, 0x2541, 0x04a2, 0x2545, 0x04a4, 0x2549, 0x04a6, 0x254d, 0x04a8, 0x2551, 0x04aa, 0x2555, 0x04ac, 0x2559, 0x04ae, 0x255d,
363 0x04b0, 0x2561, 0x04b2, 0x2565, 0x04b4, 0x2569, 0x04b6, 0x256d, 0x04b8, 0x2571, 0x04ba, 0x2575, 0x04bc, 0x2579, 0x253e, 0x467d,
364 0x08c0, 0x2981, 0x08c2, 0x2985, 0x08c4, 0x2989, 0x08c6, 0x298d, 0x08c8, 0x2991, 0x08ca, 0x2995, 0x08cc, 0x2999, 0x08ce, 0x299d,
365 0x08d0, 0x29a1, 0x08d2, 0x29a5, 0x08d4, 0x29a9, 0x08d6, 0x29ad, 0x08d8, 0x29b1, 0x08da, 0x29b5, 0x08dc, 0x29b9, 0x08de, 0x29bd,
366 0x0ce0, 0x2dc1, 0x0ce2, 0x2dc5, 0x0ce4, 0x2dc9, 0x0ce6, 0x2dcd, 0x0ce8, 0x2dd1, 0x0cea, 0x2dd5, 0x0cec, 0x2dd9, 0x0cee, 0x2ddd,
367 0x10f0, 0x31e1, 0x10f2, 0x31e5, 0x10f4, 0x31e9, 0x10f6, 0x31ed, 0x20f8, 0x41f1, 0x20fa, 0x41f5, 0x257c, 0x46f9, 0x29be, 0x4b7d
370 /* hdlc_bitstuff_byte
371 * perform HDLC bitstuffing for one input byte (8 bits, LSB first)
374 * ones number of trailing '1' bits in result before this step
375 * iwb pointer to output buffer structure (write semaphore must be held)
377 * number of trailing '1' bits in result after this step
380 static inline int hdlc_bitstuff_byte(struct isowbuf_t *iwb, unsigned char cin,
384 int shiftinc, newones;
386 /* get stuffing information for input byte
387 * value: bit 9.. 0 = result bits
388 * bit 12..10 = number of trailing '1' bits in result
389 * bit 14..13 = number of bits added by stuffing
391 stuff = stufftab[256 * ones + cin];
392 shiftinc = (stuff >> 13) & 3;
393 newones = (stuff >> 10) & 7;
396 /* append stuffed byte to output stream */
397 isowbuf_putbits(iwb, stuff, 8 + shiftinc);
402 * Perform HDLC framing with bitstuffing on a byte buffer
403 * The input buffer is regarded as a sequence of bits, starting with the least
404 * significant bit of the first byte and ending with the most significant bit
405 * of the last byte. A 16 bit FCS is appended as defined by RFC 1662.
406 * Whenever five consecutive '1' bits appear in the resulting bit sequence, a
407 * '0' bit is inserted after them.
408 * The resulting bit string and a closing flag pattern (PPP_FLAG, '01111110')
409 * are appended to the output buffer starting at the given bit position, which
410 * is assumed to already contain a leading flag.
411 * The output buffer must have sufficient length; count + count/5 + 6 bytes
412 * starting at *out are safe and are verified to be present.
415 * count number of bytes in input buffer
416 * iwb pointer to output buffer structure (write semaphore must be held)
418 * position of end of packet in output buffer on success,
419 * -EAGAIN if write semaphore busy or buffer full
422 static inline int hdlc_buildframe(struct isowbuf_t *iwb,
423 unsigned char *in, int count)
430 if (isowbuf_freebytes(iwb) < count + count / 5 + 6 ||
431 !isowbuf_startwrite(iwb)) {
432 dbg(DEBUG_ISO, "%s: %d bytes free -> -EAGAIN",
433 __func__, isowbuf_freebytes(iwb));
437 dump_bytes(DEBUG_STREAM, "snd data", in, count);
439 /* bitstuff and checksum input data */
442 while (count-- > 0) {
444 ones = hdlc_bitstuff_byte(iwb, c, ones);
445 fcs = crc_ccitt_byte(fcs, c);
448 /* bitstuff and append FCS (complemented, least significant byte first) */
450 ones = hdlc_bitstuff_byte(iwb, fcs & 0x00ff, ones);
451 ones = hdlc_bitstuff_byte(iwb, (fcs >> 8) & 0x00ff, ones);
453 /* put closing flag and repeat byte for flag idle */
454 isowbuf_putflag(iwb);
455 end = isowbuf_donewrite(iwb);
456 dump_bytes(DEBUG_STREAM_DUMP, "isowbuf", iwb->data, end + 1);
461 * Append a block of 'transparent' data to the output buffer,
462 * inverting the bytes.
463 * The output buffer must have sufficient length; count bytes
464 * starting at *out are safe and are verified to be present.
467 * count number of bytes in input buffer
468 * iwb pointer to output buffer structure (write semaphore must be held)
470 * position of end of packet in output buffer on success,
471 * -EAGAIN if write semaphore busy or buffer full
474 static inline int trans_buildframe(struct isowbuf_t *iwb,
475 unsigned char *in, int count)
480 if (unlikely(count <= 0))
481 return atomic_read(&iwb->write); /* better ideas? */
483 if (isowbuf_freebytes(iwb) < count ||
484 !isowbuf_startwrite(iwb)) {
485 dbg(DEBUG_ISO, "can't put %d bytes", count);
489 dbg(DEBUG_STREAM, "put %d bytes", count);
490 write = atomic_read(&iwb->write);
492 c = gigaset_invtab[*in++];
493 iwb->data[write++] = c;
494 write %= BAS_OUTBUFSIZE;
495 } while (--count > 0);
496 atomic_set(&iwb->write, write);
499 return isowbuf_donewrite(iwb);
502 int gigaset_isoc_buildframe(struct bc_state *bcs, unsigned char *in, int len)
506 switch (bcs->proto2) {
507 case ISDN_PROTO_L2_HDLC:
508 result = hdlc_buildframe(bcs->hw.bas->isooutbuf, in, len);
509 dbg(DEBUG_ISO, "%s: %d bytes HDLC -> %d",
510 __func__, len, result);
512 default: /* assume transparent */
513 result = trans_buildframe(bcs->hw.bas->isooutbuf, in, len);
514 dbg(DEBUG_ISO, "%s: %d bytes trans -> %d",
515 __func__, len, result);
521 * append byte c to current skb of B channel structure *bcs, updating fcs
523 static inline void hdlc_putbyte(unsigned char c, struct bc_state *bcs)
525 bcs->fcs = crc_ccitt_byte(bcs->fcs, c);
526 if (unlikely(bcs->skb == NULL)) {
530 if (unlikely(bcs->skb->len == SBUFSIZE)) {
531 warn("received oversized packet discarded");
532 bcs->hw.bas->giants++;
533 dev_kfree_skb_any(bcs->skb);
537 *gigaset_skb_put_quick(bcs->skb, 1) = c;
541 * drop partial HDLC data packet
543 static inline void hdlc_flush(struct bc_state *bcs)
545 /* clear skb or allocate new if not skipping */
546 if (likely(bcs->skb != NULL))
547 skb_trim(bcs->skb, 0);
548 else if (!bcs->ignore) {
549 if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)
550 skb_reserve(bcs->skb, HW_HDR_LEN);
552 err("could not allocate skb");
555 /* reset packet state */
556 bcs->fcs = PPP_INITFCS;
560 * process completed HDLC data packet
562 static inline void hdlc_done(struct bc_state *bcs)
564 struct sk_buff *procskb;
566 if (unlikely(bcs->ignore)) {
572 if ((procskb = bcs->skb) == NULL) {
574 dbg(DEBUG_ISO, "%s: skb=NULL", __func__);
575 gigaset_rcv_error(NULL, bcs->cs, bcs);
576 } else if (procskb->len < 2) {
577 notice("received short frame (%d octets)", procskb->len);
578 bcs->hw.bas->runts++;
579 gigaset_rcv_error(procskb, bcs->cs, bcs);
580 } else if (bcs->fcs != PPP_GOODFCS) {
581 notice("frame check error (0x%04x)", bcs->fcs);
582 bcs->hw.bas->fcserrs++;
583 gigaset_rcv_error(procskb, bcs->cs, bcs);
585 procskb->len -= 2; /* subtract FCS */
588 "%s: good frame (%d octets)", __func__, procskb->len);
589 dump_bytes(DEBUG_STREAM,
590 "rcv data", procskb->data, procskb->len);
591 bcs->hw.bas->goodbytes += procskb->len;
592 gigaset_rcv_skb(procskb, bcs->cs, bcs);
595 if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)
596 skb_reserve(bcs->skb, HW_HDR_LEN);
598 err("could not allocate skb");
599 bcs->fcs = PPP_INITFCS;
603 * drop HDLC data packet with non-integral last byte
605 static inline void hdlc_frag(struct bc_state *bcs, unsigned inbits)
607 if (unlikely(bcs->ignore)) {
613 notice("received partial byte (%d bits)", inbits);
614 bcs->hw.bas->alignerrs++;
615 gigaset_rcv_error(bcs->skb, bcs->cs, bcs);
617 if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)
618 skb_reserve(bcs->skb, HW_HDR_LEN);
620 err("could not allocate skb");
621 bcs->fcs = PPP_INITFCS;
624 /* bit counts lookup table for HDLC bit unstuffing
626 * value: bit 0..3 = number of consecutive '1' bits starting from LSB
627 * bit 4..6 = number of consecutive '1' bits starting from MSB
628 * (replacing 8 by 7 to make it fit; the algorithm won't care)
629 * bit 7 set if there are 5 or more "interior" consecutive '1' bits
631 static unsigned char bitcounts[256] = {
632 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
633 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05,
634 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
635 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x80, 0x06,
636 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
637 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05,
638 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
639 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x80, 0x81, 0x80, 0x07,
640 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14,
641 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x15,
642 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14,
643 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x90, 0x16,
644 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x24,
645 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x25,
646 0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x33, 0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x34,
647 0x40, 0x41, 0x40, 0x42, 0x40, 0x41, 0x40, 0x43, 0x50, 0x51, 0x50, 0x52, 0x60, 0x61, 0x70, 0x78
651 * perform HDLC frame processing (bit unstuffing, flag detection, FCS calculation)
652 * on a sequence of received data bytes (8 bits each, LSB first)
653 * pass on successfully received, complete frames as SKBs via gigaset_rcv_skb
654 * notify of errors via gigaset_rcv_error
655 * tally frames, errors etc. in BC structure counters
658 * count number of received bytes
659 * bcs receiving B channel structure
661 static inline void hdlc_unpack(unsigned char *src, unsigned count,
662 struct bc_state *bcs)
664 struct bas_bc_state *ubc;
666 unsigned seqlen, inbyte, inbits;
672 /* load previous state:
673 * inputstate = set of flag bits:
674 * - INS_flag_hunt: no complete opening flag received since connection setup or last abort
675 * - INS_have_data: at least one complete data byte received since last flag
676 * seqlen = number of consecutive '1' bits in last 7 input stream bits (0..7)
677 * inbyte = accumulated partial data byte (if !INS_flag_hunt)
678 * inbits = number of valid bits in inbyte, starting at LSB (0..6)
680 inputstate = bcs->inputstate;
681 seqlen = ubc->seqlen;
682 inbyte = ubc->inbyte;
683 inbits = ubc->inbits;
685 /* bit unstuffing a byte a time
686 * Take your time to understand this; it's straightforward but tedious.
687 * The "bitcounts" lookup table is used to speed up the counting of
688 * leading and trailing '1' bits.
691 unsigned char c = *src++;
692 unsigned char tabentry = bitcounts[c];
693 unsigned lead1 = tabentry & 0x0f;
694 unsigned trail1 = (tabentry >> 4) & 0x0f;
698 if (unlikely(inputstate & INS_flag_hunt)) {
701 inputstate &= ~(INS_flag_hunt | INS_have_data);
704 } else if (seqlen == 6 && trail1 != 7) {
705 /* flag completed & not followed by abort */
706 inputstate &= ~(INS_flag_hunt | INS_have_data);
707 inbyte = c >> (lead1 + 1);
710 /* interior stuffing: omitting the MSB handles most cases */
712 /* correct the incorrectly handled cases individually */
720 /* else: continue flag-hunting */
721 } else if (likely(seqlen < 5 && trail1 < 7)) {
722 /* streamlined case: 8 data bits, no stuffing */
723 inbyte |= c << inbits;
724 hdlc_putbyte(inbyte & 0xff, bcs);
725 inputstate |= INS_have_data;
727 /* inbits unchanged */
728 } else if (likely(seqlen == 6 && inbits == 7 - lead1 &&
729 trail1 + 1 == inbits &&
730 !(inputstate & INS_have_data))) {
731 /* streamlined case: flag idle - state unchanged */
732 } else if (unlikely(seqlen > 6)) {
736 inputstate |= INS_flag_hunt;
737 } else if (seqlen == 6) {
738 /* closing flag, including (6 - lead1) '1's and one '0' from inbits */
739 if (inbits > 7 - lead1) {
740 hdlc_frag(bcs, inbits + lead1 - 7);
741 inputstate &= ~INS_have_data;
743 if (inbits < 7 - lead1)
745 if (inputstate & INS_have_data) {
747 inputstate &= ~INS_have_data;
752 /* complete flag, LSB overlaps preceding flag */
756 } else if (trail1 != 7) {
758 inbyte = c >> (lead1 + 1);
761 /* interior stuffing: omitting the MSB handles most cases */
763 /* correct the incorrectly handled cases individually */
771 /* abort sequence follows, skb already empty anyway */
773 inputstate |= INS_flag_hunt;
775 } else { /* (seqlen < 6) && (seqlen == 5 || trail1 >= 7) */
782 hdlc_frag(bcs, inbits);
785 } else if (inputstate & INS_have_data)
787 inputstate &= ~INS_have_data;
788 } else if (trail1 == 7) {
792 inputstate |= INS_flag_hunt;
795 if (trail1 < 7) { /* => seqlen == 5 */
796 /* stuff bit at position lead1, no interior stuffing */
797 unsigned char mask = (1 << lead1) - 1;
798 c = (c & mask) | ((c & ~mask) >> 1);
799 inbyte |= c << inbits;
801 } else if (seqlen < 5) { /* trail1 >= 8 */
802 /* interior stuffing: omitting the MSB handles most cases */
803 /* correct the incorrectly handled cases individually */
809 inbyte |= c << inbits;
811 } else { /* seqlen == 5 && trail1 >= 8 */
813 /* stuff bit at lead1 *and* interior stuffing */
814 switch (c) { /* unstuff individually */
828 inbyte |= c << inbits;
833 hdlc_putbyte(inbyte & 0xff, bcs);
834 inputstate |= INS_have_data;
843 bcs->inputstate = inputstate;
844 ubc->seqlen = seqlen;
845 ubc->inbyte = inbyte;
846 ubc->inbits = inbits;
850 * pass on received USB frame transparently as SKB via gigaset_rcv_skb
852 * tally frames, errors etc. in BC structure counters
855 * count number of received bytes
856 * bcs receiving B channel structure
858 static inline void trans_receive(unsigned char *src, unsigned count,
859 struct bc_state *bcs)
865 if (unlikely(bcs->ignore)) {
870 if (unlikely((skb = bcs->skb) == NULL)) {
871 bcs->skb = skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN);
873 err("could not allocate skb");
876 skb_reserve(skb, HW_HDR_LEN);
878 bcs->hw.bas->goodbytes += skb->len;
879 dobytes = TRANSBUFSIZE - skb->len;
881 dst = skb_put(skb, count < dobytes ? count : dobytes);
882 while (count > 0 && dobytes > 0) {
883 *dst++ = gigaset_invtab[*src++];
888 gigaset_rcv_skb(skb, bcs->cs, bcs);
889 bcs->skb = skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN);
891 err("could not allocate skb");
894 skb_reserve(bcs->skb, HW_HDR_LEN);
895 dobytes = TRANSBUFSIZE;
900 void gigaset_isoc_receive(unsigned char *src, unsigned count, struct bc_state *bcs)
902 switch (bcs->proto2) {
903 case ISDN_PROTO_L2_HDLC:
904 hdlc_unpack(src, count, bcs);
906 default: /* assume transparent */
907 trans_receive(src, count, bcs);
911 /* == data input =========================================================== */
913 static void cmd_loop(unsigned char *src, int numbytes, struct inbuf_t *inbuf)
915 struct cardstate *cs = inbuf->cs;
916 unsigned cbytes = cs->cbytes;
919 /* copy next character, check for end of line */
920 switch (cs->respdata[cbytes] = *src++) {
924 dbg(DEBUG_TRANSCMD, "%s: End of Command (%d Bytes)",
927 gigaset_handle_modem_response(cs);
931 /* advance in line buffer, checking for overflow */
932 if (cbytes < MAX_RESP_SIZE - 1)
935 warn("response too large");
944 /* process a block of data received through the control channel
946 void gigaset_isoc_input(struct inbuf_t *inbuf)
948 struct cardstate *cs = inbuf->cs;
949 unsigned tail, head, numbytes;
952 head = atomic_read(&inbuf->head);
953 while (head != (tail = atomic_read(&inbuf->tail))) {
954 dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail);
957 src = inbuf->data + head;
958 numbytes = tail - head;
959 dbg(DEBUG_INTR, "processing %u bytes", numbytes);
961 if (atomic_read(&cs->mstate) == MS_LOCKED) {
962 gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response",
964 gigaset_if_receive(inbuf->cs, src, numbytes);
966 gigaset_dbg_buffer(DEBUG_CMD, "received response",
968 cmd_loop(src, numbytes, inbuf);
972 if (head == RBUFSIZE)
974 dbg(DEBUG_INTR, "setting head to %u", head);
975 atomic_set(&inbuf->head, head);
980 /* == data output ========================================================== */
983 * called by common.c to queue an skb for sending
984 * and start transmission if necessary
986 * B Channel control structure
989 * number of bytes accepted for sending
990 * (skb->len if ok, 0 if out of buffer space)
991 * or error code (< 0, eg. -EINVAL)
993 int gigaset_isoc_send_skb(struct bc_state *bcs, struct sk_buff *skb)
997 IFNULLRETVAL(bcs, -EFAULT);
998 IFNULLRETVAL(skb, -EFAULT);
1001 skb_queue_tail(&bcs->squeue, skb);
1003 "%s: skb queued, qlen=%d", __func__, skb_queue_len(&bcs->squeue));
1005 /* tasklet submits URB if necessary */
1006 tasklet_schedule(&bcs->hw.bas->sent_tasklet);
1008 return len; /* ok so far */