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Linux 2.6.34-rc3
[pohmelfs.git] / drivers / isdn / gigaset / isocdata.c
blob16fd3bd488834101b74a7dd316f82b6badbe8b5d
1 /*
2 * Common data handling layer for bas_gigaset
3 *
4 * Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>,
5 * Hansjoerg Lipp <hjlipp@web.de>.
6 *
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 * =====================================================================
13 */
14
15 #include "gigaset.h"
16 #include <linux/crc-ccitt.h>
17 #include <linux/bitrev.h>
18
19 /* access methods for isowbuf_t */
20 /* ============================ */
21
22 /* initialize buffer structure
23 */
24 void gigaset_isowbuf_init(struct isowbuf_t *iwb, unsigned char idle)
25 {
26 iwb->read = 0;
27 iwb->nextread = 0;
28 iwb->write = 0;
29 atomic_set(&iwb->writesem, 1);
30 iwb->wbits = 0;
31 iwb->idle = idle;
32 memset(iwb->data + BAS_OUTBUFSIZE, idle, BAS_OUTBUFPAD);
33 }
34
35 /* compute number of bytes which can be appended to buffer
36 * so that there is still room to append a maximum frame of flags
37 */
38 static inline int isowbuf_freebytes(struct isowbuf_t *iwb)
39 {
40 int read, write, freebytes;
41
42 read = iwb->read;
43 write = iwb->write;
44 freebytes = read - write;
45 if (freebytes > 0) {
46 /* no wraparound: need padding space within regular area */
47 return freebytes - BAS_OUTBUFPAD;
48 } else if (read < BAS_OUTBUFPAD) {
49 /* wraparound: can use space up to end of regular area */
50 return BAS_OUTBUFSIZE - write;
51 } else {
52 /* following the wraparound yields more space */
53 return freebytes + BAS_OUTBUFSIZE - BAS_OUTBUFPAD;
54 }
55 }
56
57 /* start writing
58 * acquire the write semaphore
59 * return true if acquired, false if busy
60 */
61 static inline int isowbuf_startwrite(struct isowbuf_t *iwb)
62 {
63 if (!atomic_dec_and_test(&iwb->writesem)) {
64 atomic_inc(&iwb->writesem);
65 gig_dbg(DEBUG_ISO, "%s: couldn't acquire iso write semaphore",
66 __func__);
67 return 0;
68 }
69 gig_dbg(DEBUG_ISO,
70 "%s: acquired iso write semaphore, data[write]=%02x, nbits=%d",
71 __func__, iwb->data[iwb->write], iwb->wbits);
72 return 1;
73 }
74
75 /* finish writing
76 * release the write semaphore
77 * returns the current write position
78 */
79 static inline int isowbuf_donewrite(struct isowbuf_t *iwb)
80 {
81 int write = iwb->write;
82 atomic_inc(&iwb->writesem);
83 return write;
84 }
85
86 /* append bits to buffer without any checks
87 * - data contains bits to append, starting at LSB
88 * - nbits is number of bits to append (0..24)
89 * must be called with the write semaphore held
90 * If more than nbits bits are set in data, the extraneous bits are set in the
91 * buffer too, but the write position is only advanced by nbits.
92 */
93 static inline void isowbuf_putbits(struct isowbuf_t *iwb, u32 data, int nbits)
94 {
95 int write = iwb->write;
96 data <<= iwb->wbits;
97 data |= iwb->data[write];
98 nbits += iwb->wbits;
99 while (nbits >= 8) {
100 iwb->data[write++] = data & 0xff;
101 write %= BAS_OUTBUFSIZE;
102 data >>= 8;
103 nbits -= 8;
104 }
105 iwb->wbits = nbits;
106 iwb->data[write] = data & 0xff;
107 iwb->write = write;
108 }
109
110 /* put final flag on HDLC bitstream
111 * also sets the idle fill byte to the correspondingly shifted flag pattern
112 * must be called with the write semaphore held
113 */
114 static inline void isowbuf_putflag(struct isowbuf_t *iwb)
115 {
116 int write;
117
118 /* add two flags, thus reliably covering one byte */
119 isowbuf_putbits(iwb, 0x7e7e, 8);
120 /* recover the idle flag byte */
121 write = iwb->write;
122 iwb->idle = iwb->data[write];
123 gig_dbg(DEBUG_ISO, "idle fill byte %02x", iwb->idle);
124 /* mask extraneous bits in buffer */
125 iwb->data[write] &= (1 << iwb->wbits) - 1;
126 }
127
128 /* retrieve a block of bytes for sending
129 * The requested number of bytes is provided as a contiguous block.
130 * If necessary, the frame is filled to the requested number of bytes
131 * with the idle value.
132 * returns offset to frame, < 0 on busy or error
133 */
134 int gigaset_isowbuf_getbytes(struct isowbuf_t *iwb, int size)
135 {
136 int read, write, limit, src, dst;
137 unsigned char pbyte;
138
139 read = iwb->nextread;
140 write = iwb->write;
141 if (likely(read == write)) {
142 /* return idle frame */
143 return read < BAS_OUTBUFPAD ?
144 BAS_OUTBUFSIZE : read - BAS_OUTBUFPAD;
145 }
146
147 limit = read + size;
148 gig_dbg(DEBUG_STREAM, "%s: read=%d write=%d limit=%d",
149 __func__, read, write, limit);
150 #ifdef CONFIG_GIGASET_DEBUG
151 if (unlikely(size < 0 || size > BAS_OUTBUFPAD)) {
152 pr_err("invalid size %d\n", size);
153 return -EINVAL;
154 }
155 #endif
156
157 if (read < write) {
158 /* no wraparound in valid data */
159 if (limit >= write) {
160 /* append idle frame */
161 if (!isowbuf_startwrite(iwb))
162 return -EBUSY;
163 /* write position could have changed */
164 write = iwb->write;
165 if (limit >= write) {
166 pbyte = iwb->data[write]; /* save
167 partial byte */
168 limit = write + BAS_OUTBUFPAD;
169 gig_dbg(DEBUG_STREAM,
170 "%s: filling %d->%d with %02x",
171 __func__, write, limit, iwb->idle);
172 if (write + BAS_OUTBUFPAD < BAS_OUTBUFSIZE)
173 memset(iwb->data + write, iwb->idle,
174 BAS_OUTBUFPAD);
175 else {
176 /* wraparound, fill entire pad area */
177 memset(iwb->data + write, iwb->idle,
178 BAS_OUTBUFSIZE + BAS_OUTBUFPAD
179 - write);
180 limit = 0;
181 }
182 gig_dbg(DEBUG_STREAM,
183 "%s: restoring %02x at %d",
184 __func__, pbyte, limit);
185 iwb->data[limit] = pbyte; /* restore
186 partial byte */
187 iwb->write = limit;
188 }
189 isowbuf_donewrite(iwb);
190 }
191 } else {
192 /* valid data wraparound */
193 if (limit >= BAS_OUTBUFSIZE) {
194 /* copy wrapped part into pad area */
195 src = 0;
196 dst = BAS_OUTBUFSIZE;
197 while (dst < limit && src < write)
198 iwb->data[dst++] = iwb->data[src++];
199 if (dst <= limit) {
200 /* fill pad area with idle byte */
201 memset(iwb->data + dst, iwb->idle,
202 BAS_OUTBUFSIZE + BAS_OUTBUFPAD - dst);
203 }
204 limit = src;
205 }
206 }
207 iwb->nextread = limit;
208 return read;
209 }
210
211 /* dump_bytes
212 * write hex bytes to syslog for debugging
213 */
214 static inline void dump_bytes(enum debuglevel level, const char *tag,
215 unsigned char *bytes, int count)
216 {
217 #ifdef CONFIG_GIGASET_DEBUG
218 unsigned char c;
219 static char dbgline[3 * 32 + 1];
220 int i = 0;
221
222 if (!(gigaset_debuglevel & level))
223 return;
224
225 while (count-- > 0) {
226 if (i > sizeof(dbgline) - 4) {
227 dbgline[i] = '\0';
228 gig_dbg(level, "%s:%s", tag, dbgline);
229 i = 0;
230 }
231 c = *bytes++;
232 dbgline[i] = (i && !(i % 12)) ? '-' : ' ';
233 i++;
234 dbgline[i++] = hex_asc_hi(c);
235 dbgline[i++] = hex_asc_lo(c);
236 }
237 dbgline[i] = '\0';
238 gig_dbg(level, "%s:%s", tag, dbgline);
239 #endif
240 }
241
242 /*============================================================================*/
243
244 /* bytewise HDLC bitstuffing via table lookup
245 * lookup table: 5 subtables for 0..4 preceding consecutive '1' bits
246 * index: 256*(number of preceding '1' bits) + (next byte to stuff)
247 * value: bit 9.. 0 = result bits
248 * bit 12..10 = number of trailing '1' bits in result
249 * bit 14..13 = number of bits added by stuffing
250 */
251 static const u16 stufftab[5 * 256] = {
252 /* previous 1s = 0: */
253 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
254 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x201f,
255 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
256 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x205f,
257 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
258 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x209f,
259 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
260 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20df,
261 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x048f,
262 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x251f,
263 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x04af,
264 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x255f,
265 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x08cf,
266 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x299f,
267 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x0cef,
268 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x2ddf,
269
270 /* previous 1s = 1: */
271 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x200f,
272 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x202f,
273 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x204f,
274 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x206f,
275 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x208f,
276 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20af,
277 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20cf,
278 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20ef,
279 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x250f,
280 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x252f,
281 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x254f,
282 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x256f,
283 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x298f,
284 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29af,
285 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dcf,
286 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x31ef,
287
288 /* previous 1s = 2: */
289 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x2007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x2017,
290 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x2027, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x2037,
291 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x2047, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x2057,
292 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x2067, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x2077,
293 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x2087, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x2097,
294 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x20a7, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20b7,
295 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x20c7, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20d7,
296 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x20e7, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20f7,
297 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x2507, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x2517,
298 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x2527, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x2537,
299 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x2547, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x2557,
300 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x2567, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x2577,
301 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x2987, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x2997,
302 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x29a7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29b7,
303 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dc7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dd7,
304 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x31e7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x41f7,
305
306 /* previous 1s = 3: */
307 0x0000, 0x0001, 0x0002, 0x2003, 0x0004, 0x0005, 0x0006, 0x200b, 0x0008, 0x0009, 0x000a, 0x2013, 0x000c, 0x000d, 0x000e, 0x201b,
308 0x0010, 0x0011, 0x0012, 0x2023, 0x0014, 0x0015, 0x0016, 0x202b, 0x0018, 0x0019, 0x001a, 0x2033, 0x001c, 0x001d, 0x001e, 0x203b,
309 0x0020, 0x0021, 0x0022, 0x2043, 0x0024, 0x0025, 0x0026, 0x204b, 0x0028, 0x0029, 0x002a, 0x2053, 0x002c, 0x002d, 0x002e, 0x205b,
310 0x0030, 0x0031, 0x0032, 0x2063, 0x0034, 0x0035, 0x0036, 0x206b, 0x0038, 0x0039, 0x003a, 0x2073, 0x003c, 0x003d, 0x203e, 0x207b,
311 0x0040, 0x0041, 0x0042, 0x2083, 0x0044, 0x0045, 0x0046, 0x208b, 0x0048, 0x0049, 0x004a, 0x2093, 0x004c, 0x004d, 0x004e, 0x209b,
312 0x0050, 0x0051, 0x0052, 0x20a3, 0x0054, 0x0055, 0x0056, 0x20ab, 0x0058, 0x0059, 0x005a, 0x20b3, 0x005c, 0x005d, 0x005e, 0x20bb,
313 0x0060, 0x0061, 0x0062, 0x20c3, 0x0064, 0x0065, 0x0066, 0x20cb, 0x0068, 0x0069, 0x006a, 0x20d3, 0x006c, 0x006d, 0x006e, 0x20db,
314 0x0070, 0x0071, 0x0072, 0x20e3, 0x0074, 0x0075, 0x0076, 0x20eb, 0x0078, 0x0079, 0x007a, 0x20f3, 0x207c, 0x207d, 0x20be, 0x40fb,
315 0x0480, 0x0481, 0x0482, 0x2503, 0x0484, 0x0485, 0x0486, 0x250b, 0x0488, 0x0489, 0x048a, 0x2513, 0x048c, 0x048d, 0x048e, 0x251b,
316 0x0490, 0x0491, 0x0492, 0x2523, 0x0494, 0x0495, 0x0496, 0x252b, 0x0498, 0x0499, 0x049a, 0x2533, 0x049c, 0x049d, 0x049e, 0x253b,
317 0x04a0, 0x04a1, 0x04a2, 0x2543, 0x04a4, 0x04a5, 0x04a6, 0x254b, 0x04a8, 0x04a9, 0x04aa, 0x2553, 0x04ac, 0x04ad, 0x04ae, 0x255b,
318 0x04b0, 0x04b1, 0x04b2, 0x2563, 0x04b4, 0x04b5, 0x04b6, 0x256b, 0x04b8, 0x04b9, 0x04ba, 0x2573, 0x04bc, 0x04bd, 0x253e, 0x257b,
319 0x08c0, 0x08c1, 0x08c2, 0x2983, 0x08c4, 0x08c5, 0x08c6, 0x298b, 0x08c8, 0x08c9, 0x08ca, 0x2993, 0x08cc, 0x08cd, 0x08ce, 0x299b,
320 0x08d0, 0x08d1, 0x08d2, 0x29a3, 0x08d4, 0x08d5, 0x08d6, 0x29ab, 0x08d8, 0x08d9, 0x08da, 0x29b3, 0x08dc, 0x08dd, 0x08de, 0x29bb,
321 0x0ce0, 0x0ce1, 0x0ce2, 0x2dc3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dcb, 0x0ce8, 0x0ce9, 0x0cea, 0x2dd3, 0x0cec, 0x0ced, 0x0cee, 0x2ddb,
322 0x10f0, 0x10f1, 0x10f2, 0x31e3, 0x10f4, 0x10f5, 0x10f6, 0x31eb, 0x20f8, 0x20f9, 0x20fa, 0x41f3, 0x257c, 0x257d, 0x29be, 0x46fb,
323
324 /* previous 1s = 4: */
325 0x0000, 0x2001, 0x0002, 0x2005, 0x0004, 0x2009, 0x0006, 0x200d, 0x0008, 0x2011, 0x000a, 0x2015, 0x000c, 0x2019, 0x000e, 0x201d,
326 0x0010, 0x2021, 0x0012, 0x2025, 0x0014, 0x2029, 0x0016, 0x202d, 0x0018, 0x2031, 0x001a, 0x2035, 0x001c, 0x2039, 0x001e, 0x203d,
327 0x0020, 0x2041, 0x0022, 0x2045, 0x0024, 0x2049, 0x0026, 0x204d, 0x0028, 0x2051, 0x002a, 0x2055, 0x002c, 0x2059, 0x002e, 0x205d,
328 0x0030, 0x2061, 0x0032, 0x2065, 0x0034, 0x2069, 0x0036, 0x206d, 0x0038, 0x2071, 0x003a, 0x2075, 0x003c, 0x2079, 0x203e, 0x407d,
329 0x0040, 0x2081, 0x0042, 0x2085, 0x0044, 0x2089, 0x0046, 0x208d, 0x0048, 0x2091, 0x004a, 0x2095, 0x004c, 0x2099, 0x004e, 0x209d,
330 0x0050, 0x20a1, 0x0052, 0x20a5, 0x0054, 0x20a9, 0x0056, 0x20ad, 0x0058, 0x20b1, 0x005a, 0x20b5, 0x005c, 0x20b9, 0x005e, 0x20bd,
331 0x0060, 0x20c1, 0x0062, 0x20c5, 0x0064, 0x20c9, 0x0066, 0x20cd, 0x0068, 0x20d1, 0x006a, 0x20d5, 0x006c, 0x20d9, 0x006e, 0x20dd,
332 0x0070, 0x20e1, 0x0072, 0x20e5, 0x0074, 0x20e9, 0x0076, 0x20ed, 0x0078, 0x20f1, 0x007a, 0x20f5, 0x207c, 0x40f9, 0x20be, 0x417d,
333 0x0480, 0x2501, 0x0482, 0x2505, 0x0484, 0x2509, 0x0486, 0x250d, 0x0488, 0x2511, 0x048a, 0x2515, 0x048c, 0x2519, 0x048e, 0x251d,
334 0x0490, 0x2521, 0x0492, 0x2525, 0x0494, 0x2529, 0x0496, 0x252d, 0x0498, 0x2531, 0x049a, 0x2535, 0x049c, 0x2539, 0x049e, 0x253d,
335 0x04a0, 0x2541, 0x04a2, 0x2545, 0x04a4, 0x2549, 0x04a6, 0x254d, 0x04a8, 0x2551, 0x04aa, 0x2555, 0x04ac, 0x2559, 0x04ae, 0x255d,
336 0x04b0, 0x2561, 0x04b2, 0x2565, 0x04b4, 0x2569, 0x04b6, 0x256d, 0x04b8, 0x2571, 0x04ba, 0x2575, 0x04bc, 0x2579, 0x253e, 0x467d,
337 0x08c0, 0x2981, 0x08c2, 0x2985, 0x08c4, 0x2989, 0x08c6, 0x298d, 0x08c8, 0x2991, 0x08ca, 0x2995, 0x08cc, 0x2999, 0x08ce, 0x299d,
338 0x08d0, 0x29a1, 0x08d2, 0x29a5, 0x08d4, 0x29a9, 0x08d6, 0x29ad, 0x08d8, 0x29b1, 0x08da, 0x29b5, 0x08dc, 0x29b9, 0x08de, 0x29bd,
339 0x0ce0, 0x2dc1, 0x0ce2, 0x2dc5, 0x0ce4, 0x2dc9, 0x0ce6, 0x2dcd, 0x0ce8, 0x2dd1, 0x0cea, 0x2dd5, 0x0cec, 0x2dd9, 0x0cee, 0x2ddd,
340 0x10f0, 0x31e1, 0x10f2, 0x31e5, 0x10f4, 0x31e9, 0x10f6, 0x31ed, 0x20f8, 0x41f1, 0x20fa, 0x41f5, 0x257c, 0x46f9, 0x29be, 0x4b7d
341 };
342
343 /* hdlc_bitstuff_byte
344 * perform HDLC bitstuffing for one input byte (8 bits, LSB first)
345 * parameters:
346 * cin input byte
347 * ones number of trailing '1' bits in result before this step
348 * iwb pointer to output buffer structure
349 * (write semaphore must be held)
350 * return value:
351 * number of trailing '1' bits in result after this step
352 */
353
354 static inline int hdlc_bitstuff_byte(struct isowbuf_t *iwb, unsigned char cin,
355 int ones)
356 {
357 u16 stuff;
358 int shiftinc, newones;
359
360 /* get stuffing information for input byte
361 * value: bit 9.. 0 = result bits
362 * bit 12..10 = number of trailing '1' bits in result
363 * bit 14..13 = number of bits added by stuffing
364 */
365 stuff = stufftab[256 * ones + cin];
366 shiftinc = (stuff >> 13) & 3;
367 newones = (stuff >> 10) & 7;
368 stuff &= 0x3ff;
369
370 /* append stuffed byte to output stream */
371 isowbuf_putbits(iwb, stuff, 8 + shiftinc);
372 return newones;
373 }
374
375 /* hdlc_buildframe
376 * Perform HDLC framing with bitstuffing on a byte buffer
377 * The input buffer is regarded as a sequence of bits, starting with the least
378 * significant bit of the first byte and ending with the most significant bit
379 * of the last byte. A 16 bit FCS is appended as defined by RFC 1662.
380 * Whenever five consecutive '1' bits appear in the resulting bit sequence, a
381 * '0' bit is inserted after them.
382 * The resulting bit string and a closing flag pattern (PPP_FLAG, '01111110')
383 * are appended to the output buffer starting at the given bit position, which
384 * is assumed to already contain a leading flag.
385 * The output buffer must have sufficient length; count + count/5 + 6 bytes
386 * starting at *out are safe and are verified to be present.
387 * parameters:
388 * in input buffer
389 * count number of bytes in input buffer
390 * iwb pointer to output buffer structure
391 * (write semaphore must be held)
392 * return value:
393 * position of end of packet in output buffer on success,
394 * -EAGAIN if write semaphore busy or buffer full
395 */
396
397 static inline int hdlc_buildframe(struct isowbuf_t *iwb,
398 unsigned char *in, int count)
399 {
400 int ones;
401 u16 fcs;
402 int end;
403 unsigned char c;
404
405 if (isowbuf_freebytes(iwb) < count + count / 5 + 6 ||
406 !isowbuf_startwrite(iwb)) {
407 gig_dbg(DEBUG_ISO, "%s: %d bytes free -> -EAGAIN",
408 __func__, isowbuf_freebytes(iwb));
409 return -EAGAIN;
410 }
411
412 dump_bytes(DEBUG_STREAM_DUMP, "snd data", in, count);
413
414 /* bitstuff and checksum input data */
415 fcs = PPP_INITFCS;
416 ones = 0;
417 while (count-- > 0) {
418 c = *in++;
419 ones = hdlc_bitstuff_byte(iwb, c, ones);
420 fcs = crc_ccitt_byte(fcs, c);
421 }
422
423 /* bitstuff and append FCS
424 * (complemented, least significant byte first) */
425 fcs ^= 0xffff;
426 ones = hdlc_bitstuff_byte(iwb, fcs & 0x00ff, ones);
427 ones = hdlc_bitstuff_byte(iwb, (fcs >> 8) & 0x00ff, ones);
428
429 /* put closing flag and repeat byte for flag idle */
430 isowbuf_putflag(iwb);
431 end = isowbuf_donewrite(iwb);
432 return end;
433 }
434
435 /* trans_buildframe
436 * Append a block of 'transparent' data to the output buffer,
437 * inverting the bytes.
438 * The output buffer must have sufficient length; count bytes
439 * starting at *out are safe and are verified to be present.
440 * parameters:
441 * in input buffer
442 * count number of bytes in input buffer
443 * iwb pointer to output buffer structure
444 * (write semaphore must be held)
445 * return value:
446 * position of end of packet in output buffer on success,
447 * -EAGAIN if write semaphore busy or buffer full
448 */
449
450 static inline int trans_buildframe(struct isowbuf_t *iwb,
451 unsigned char *in, int count)
452 {
453 int write;
454 unsigned char c;
455
456 if (unlikely(count <= 0))
457 return iwb->write;
458
459 if (isowbuf_freebytes(iwb) < count ||
460 !isowbuf_startwrite(iwb)) {
461 gig_dbg(DEBUG_ISO, "can't put %d bytes", count);
462 return -EAGAIN;
463 }
464
465 gig_dbg(DEBUG_STREAM, "put %d bytes", count);
466 dump_bytes(DEBUG_STREAM_DUMP, "snd data", in, count);
467
468 write = iwb->write;
469 do {
470 c = bitrev8(*in++);
471 iwb->data[write++] = c;
472 write %= BAS_OUTBUFSIZE;
473 } while (--count > 0);
474 iwb->write = write;
475 iwb->idle = c;
476
477 return isowbuf_donewrite(iwb);
478 }
479
480 int gigaset_isoc_buildframe(struct bc_state *bcs, unsigned char *in, int len)
481 {
482 int result;
483
484 switch (bcs->proto2) {
485 case L2_HDLC:
486 result = hdlc_buildframe(bcs->hw.bas->isooutbuf, in, len);
487 gig_dbg(DEBUG_ISO, "%s: %d bytes HDLC -> %d",
488 __func__, len, result);
489 break;
490 default: /* assume transparent */
491 result = trans_buildframe(bcs->hw.bas->isooutbuf, in, len);
492 gig_dbg(DEBUG_ISO, "%s: %d bytes trans -> %d",
493 __func__, len, result);
494 }
495 return result;
496 }
497
498 /* hdlc_putbyte
499 * append byte c to current skb of B channel structure *bcs, updating fcs
500 */
501 static inline void hdlc_putbyte(unsigned char c, struct bc_state *bcs)
502 {
503 bcs->fcs = crc_ccitt_byte(bcs->fcs, c);
504 if (unlikely(bcs->skb == NULL)) {
505 /* skipping */
506 return;
507 }
508 if (unlikely(bcs->skb->len == SBUFSIZE)) {
509 dev_warn(bcs->cs->dev, "received oversized packet discarded\n");
510 bcs->hw.bas->giants++;
511 dev_kfree_skb_any(bcs->skb);
512 bcs->skb = NULL;
513 return;
514 }
515 *__skb_put(bcs->skb, 1) = c;
516 }
517
518 /* hdlc_flush
519 * drop partial HDLC data packet
520 */
521 static inline void hdlc_flush(struct bc_state *bcs)
522 {
523 /* clear skb or allocate new if not skipping */
524 if (likely(bcs->skb != NULL))
525 skb_trim(bcs->skb, 0);
526 else if (!bcs->ignore) {
527 bcs->skb = dev_alloc_skb(SBUFSIZE + bcs->cs->hw_hdr_len);
528 if (bcs->skb)
529 skb_reserve(bcs->skb, bcs->cs->hw_hdr_len);
530 else
531 dev_err(bcs->cs->dev, "could not allocate skb\n");
532 }
533
534 /* reset packet state */
535 bcs->fcs = PPP_INITFCS;
536 }
537
538 /* hdlc_done
539 * process completed HDLC data packet
540 */
541 static inline void hdlc_done(struct bc_state *bcs)
542 {
543 struct cardstate *cs = bcs->cs;
544 struct sk_buff *procskb;
545 unsigned int len;
546
547 if (unlikely(bcs->ignore)) {
548 bcs->ignore--;
549 hdlc_flush(bcs);
550 return;
551 }
552 procskb = bcs->skb;
553 if (procskb == NULL) {
554 /* previous error */
555 gig_dbg(DEBUG_ISO, "%s: skb=NULL", __func__);
556 gigaset_isdn_rcv_err(bcs);
557 } else if (procskb->len < 2) {
558 dev_notice(cs->dev, "received short frame (%d octets)\n",
559 procskb->len);
560 bcs->hw.bas->runts++;
561 dev_kfree_skb_any(procskb);
562 gigaset_isdn_rcv_err(bcs);
563 } else if (bcs->fcs != PPP_GOODFCS) {
564 dev_notice(cs->dev, "frame check error (0x%04x)\n", bcs->fcs);
565 bcs->hw.bas->fcserrs++;
566 dev_kfree_skb_any(procskb);
567 gigaset_isdn_rcv_err(bcs);
568 } else {
569 len = procskb->len;
570 __skb_trim(procskb, len -= 2); /* subtract FCS */
571 gig_dbg(DEBUG_ISO, "%s: good frame (%d octets)", __func__, len);
572 dump_bytes(DEBUG_STREAM_DUMP,
573 "rcv data", procskb->data, len);
574 bcs->hw.bas->goodbytes += len;
575 gigaset_skb_rcvd(bcs, procskb);
576 }
577
578 bcs->skb = dev_alloc_skb(SBUFSIZE + cs->hw_hdr_len);
579 if (bcs->skb)
580 skb_reserve(bcs->skb, cs->hw_hdr_len);
581 else
582 dev_err(cs->dev, "could not allocate skb\n");
583 bcs->fcs = PPP_INITFCS;
584 }
585
586 /* hdlc_frag
587 * drop HDLC data packet with non-integral last byte
588 */
589 static inline void hdlc_frag(struct bc_state *bcs, unsigned inbits)
590 {
591 if (unlikely(bcs->ignore)) {
592 bcs->ignore--;
593 hdlc_flush(bcs);
594 return;
595 }
596
597 dev_notice(bcs->cs->dev, "received partial byte (%d bits)\n", inbits);
598 bcs->hw.bas->alignerrs++;
599 gigaset_isdn_rcv_err(bcs);
600 __skb_trim(bcs->skb, 0);
601 bcs->fcs = PPP_INITFCS;
602 }
603
604 /* bit counts lookup table for HDLC bit unstuffing
605 * index: input byte
606 * value: bit 0..3 = number of consecutive '1' bits starting from LSB
607 * bit 4..6 = number of consecutive '1' bits starting from MSB
608 * (replacing 8 by 7 to make it fit; the algorithm won't care)
609 * bit 7 set if there are 5 or more "interior" consecutive '1' bits
610 */
611 static const unsigned char bitcounts[256] = {
612 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
613 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05,
614 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
615 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x80, 0x06,
616 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
617 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05,
618 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04,
619 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x80, 0x81, 0x80, 0x07,
620 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14,
621 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x15,
622 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14,
623 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x90, 0x16,
624 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x24,
625 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x25,
626 0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x33, 0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x34,
627 0x40, 0x41, 0x40, 0x42, 0x40, 0x41, 0x40, 0x43, 0x50, 0x51, 0x50, 0x52, 0x60, 0x61, 0x70, 0x78
628 };
629
630 /* hdlc_unpack
631 * perform HDLC frame processing (bit unstuffing, flag detection, FCS
632 * calculation) on a sequence of received data bytes (8 bits each, LSB first)
633 * pass on successfully received, complete frames as SKBs via gigaset_skb_rcvd
634 * notify of errors via gigaset_isdn_rcv_err
635 * tally frames, errors etc. in BC structure counters
636 * parameters:
637 * src received data
638 * count number of received bytes
639 * bcs receiving B channel structure
640 */
641 static inline void hdlc_unpack(unsigned char *src, unsigned count,
642 struct bc_state *bcs)
643 {
644 struct bas_bc_state *ubc = bcs->hw.bas;
645 int inputstate;
646 unsigned seqlen, inbyte, inbits;
647
648 /* load previous state:
649 * inputstate = set of flag bits:
650 * - INS_flag_hunt: no complete opening flag received since connection
651 * setup or last abort
652 * - INS_have_data: at least one complete data byte received since last
653 * flag
654 * seqlen = number of consecutive '1' bits in last 7 input stream bits
655 * (0..7)
656 * inbyte = accumulated partial data byte (if !INS_flag_hunt)
657 * inbits = number of valid bits in inbyte, starting at LSB (0..6)
658 */
659 inputstate = bcs->inputstate;
660 seqlen = ubc->seqlen;
661 inbyte = ubc->inbyte;
662 inbits = ubc->inbits;
663
664 /* bit unstuffing a byte a time
665 * Take your time to understand this; it's straightforward but tedious.
666 * The "bitcounts" lookup table is used to speed up the counting of
667 * leading and trailing '1' bits.
668 */
669 while (count--) {
670 unsigned char c = *src++;
671 unsigned char tabentry = bitcounts[c];
672 unsigned lead1 = tabentry & 0x0f;
673 unsigned trail1 = (tabentry >> 4) & 0x0f;
674
675 seqlen += lead1;
676
677 if (unlikely(inputstate & INS_flag_hunt)) {
678 if (c == PPP_FLAG) {
679 /* flag-in-one */
680 inputstate &= ~(INS_flag_hunt | INS_have_data);
681 inbyte = 0;
682 inbits = 0;
683 } else if (seqlen == 6 && trail1 != 7) {
684 /* flag completed & not followed by abort */
685 inputstate &= ~(INS_flag_hunt | INS_have_data);
686 inbyte = c >> (lead1 + 1);
687 inbits = 7 - lead1;
688 if (trail1 >= 8) {
689 /* interior stuffing:
690 * omitting the MSB handles most cases,
691 * correct the incorrectly handled
692 * cases individually */
693 inbits--;
694 switch (c) {
695 case 0xbe:
696 inbyte = 0x3f;
697 break;
698 }
699 }
700 }
701 /* else: continue flag-hunting */
702 } else if (likely(seqlen < 5 && trail1 < 7)) {
703 /* streamlined case: 8 data bits, no stuffing */
704 inbyte |= c << inbits;
705 hdlc_putbyte(inbyte & 0xff, bcs);
706 inputstate |= INS_have_data;
707 inbyte >>= 8;
708 /* inbits unchanged */
709 } else if (likely(seqlen == 6 && inbits == 7 - lead1 &&
710 trail1 + 1 == inbits &&
711 !(inputstate & INS_have_data))) {
712 /* streamlined case: flag idle - state unchanged */
713 } else if (unlikely(seqlen > 6)) {
714 /* abort sequence */
715 ubc->aborts++;
716 hdlc_flush(bcs);
717 inputstate |= INS_flag_hunt;
718 } else if (seqlen == 6) {
719 /* closing flag, including (6 - lead1) '1's
720 * and one '0' from inbits */
721 if (inbits > 7 - lead1) {
722 hdlc_frag(bcs, inbits + lead1 - 7);
723 inputstate &= ~INS_have_data;
724 } else {
725 if (inbits < 7 - lead1)
726 ubc->stolen0s++;
727 if (inputstate & INS_have_data) {
728 hdlc_done(bcs);
729 inputstate &= ~INS_have_data;
730 }
731 }
732
733 if (c == PPP_FLAG) {
734 /* complete flag, LSB overlaps preceding flag */
735 ubc->shared0s++;
736 inbits = 0;
737 inbyte = 0;
738 } else if (trail1 != 7) {
739 /* remaining bits */
740 inbyte = c >> (lead1 + 1);
741 inbits = 7 - lead1;
742 if (trail1 >= 8) {
743 /* interior stuffing:
744 * omitting the MSB handles most cases,
745 * correct the incorrectly handled
746 * cases individually */
747 inbits--;
748 switch (c) {
749 case 0xbe:
750 inbyte = 0x3f;
751 break;
752 }
753 }
754 } else {
755 /* abort sequence follows,
756 * skb already empty anyway */
757 ubc->aborts++;
758 inputstate |= INS_flag_hunt;
759 }
760 } else { /* (seqlen < 6) && (seqlen == 5 || trail1 >= 7) */
761
762 if (c == PPP_FLAG) {
763 /* complete flag */
764 if (seqlen == 5)
765 ubc->stolen0s++;
766 if (inbits) {
767 hdlc_frag(bcs, inbits);
768 inbits = 0;
769 inbyte = 0;
770 } else if (inputstate & INS_have_data)
771 hdlc_done(bcs);
772 inputstate &= ~INS_have_data;
773 } else if (trail1 == 7) {
774 /* abort sequence */
775 ubc->aborts++;
776 hdlc_flush(bcs);
777 inputstate |= INS_flag_hunt;
778 } else {
779 /* stuffed data */
780 if (trail1 < 7) { /* => seqlen == 5 */
781 /* stuff bit at position lead1,
782 * no interior stuffing */
783 unsigned char mask = (1 << lead1) - 1;
784 c = (c & mask) | ((c & ~mask) >> 1);
785 inbyte |= c << inbits;
786 inbits += 7;
787 } else if (seqlen < 5) { /* trail1 >= 8 */
788 /* interior stuffing:
789 * omitting the MSB handles most cases,
790 * correct the incorrectly handled
791 * cases individually */
792 switch (c) {
793 case 0xbe:
794 c = 0x7e;
795 break;
796 }
797 inbyte |= c << inbits;
798 inbits += 7;
799 } else { /* seqlen == 5 && trail1 >= 8 */
800
801 /* stuff bit at lead1 *and* interior
802 * stuffing -- unstuff individually */
803 switch (c) {
804 case 0x7d:
805 c = 0x3f;
806 break;
807 case 0xbe:
808 c = 0x3f;
809 break;
810 case 0x3e:
811 c = 0x1f;
812 break;
813 case 0x7c:
814 c = 0x3e;
815 break;
816 }
817 inbyte |= c << inbits;
818 inbits += 6;
819 }
820 if (inbits >= 8) {
821 inbits -= 8;
822 hdlc_putbyte(inbyte & 0xff, bcs);
823 inputstate |= INS_have_data;
824 inbyte >>= 8;
825 }
826 }
827 }
828 seqlen = trail1 & 7;
829 }
830
831 /* save new state */
832 bcs->inputstate = inputstate;
833 ubc->seqlen = seqlen;
834 ubc->inbyte = inbyte;
835 ubc->inbits = inbits;
836 }
837
838 /* trans_receive
839 * pass on received USB frame transparently as SKB via gigaset_skb_rcvd
840 * invert bytes
841 * tally frames, errors etc. in BC structure counters
842 * parameters:
843 * src received data
844 * count number of received bytes
845 * bcs receiving B channel structure
846 */
847 static inline void trans_receive(unsigned char *src, unsigned count,
848 struct bc_state *bcs)
849 {
850 struct cardstate *cs = bcs->cs;
851 struct sk_buff *skb;
852 int dobytes;
853 unsigned char *dst;
854
855 if (unlikely(bcs->ignore)) {
856 bcs->ignore--;
857 hdlc_flush(bcs);
858 return;
859 }
860 skb = bcs->skb;
861 if (unlikely(skb == NULL)) {
862 bcs->skb = skb = dev_alloc_skb(SBUFSIZE + cs->hw_hdr_len);
863 if (!skb) {
864 dev_err(cs->dev, "could not allocate skb\n");
865 return;
866 }
867 skb_reserve(skb, cs->hw_hdr_len);
868 }
869 bcs->hw.bas->goodbytes += skb->len;
870 dobytes = TRANSBUFSIZE - skb->len;
871 while (count > 0) {
872 dst = skb_put(skb, count < dobytes ? count : dobytes);
873 while (count > 0 && dobytes > 0) {
874 *dst++ = bitrev8(*src++);
875 count--;
876 dobytes--;
877 }
878 if (dobytes == 0) {
879 dump_bytes(DEBUG_STREAM_DUMP,
880 "rcv data", skb->data, skb->len);
881 gigaset_skb_rcvd(bcs, skb);
882 bcs->skb = skb =
883 dev_alloc_skb(SBUFSIZE + cs->hw_hdr_len);
884 if (!skb) {
885 dev_err(cs->dev, "could not allocate skb\n");
886 return;
887 }
888 skb_reserve(skb, cs->hw_hdr_len);
889 dobytes = TRANSBUFSIZE;
890 }
891 }
892 }
893
894 void gigaset_isoc_receive(unsigned char *src, unsigned count,
895 struct bc_state *bcs)
896 {
897 switch (bcs->proto2) {
898 case L2_HDLC:
899 hdlc_unpack(src, count, bcs);
900 break;
901 default: /* assume transparent */
902 trans_receive(src, count, bcs);
903 }
904 }
905
906 /* == data input =========================================================== */
907
908 /* process a block of received bytes in command mode (mstate != MS_LOCKED)
909 * Append received bytes to the command response buffer and forward them
910 * line by line to the response handler.
911 * Note: Received lines may be terminated by CR, LF, or CR LF, which will be
912 * removed before passing the line to the response handler.
913 */
914 static void cmd_loop(unsigned char *src, int numbytes, struct inbuf_t *inbuf)
915 {
916 struct cardstate *cs = inbuf->cs;
917 unsigned cbytes = cs->cbytes;
918 unsigned char c;
919
920 while (numbytes--) {
921 c = *src++;
922 switch (c) {
923 case '\n':
924 if (cbytes == 0 && cs->respdata[0] == '\r') {
925 /* collapse LF with preceding CR */
926 cs->respdata[0] = 0;
927 break;
928 }
929 /* --v-- fall through --v-- */
930 case '\r':
931 /* end of message line, pass to response handler */
932 if (cbytes >= MAX_RESP_SIZE) {
933 dev_warn(cs->dev, "response too large (%d)\n",
934 cbytes);
935 cbytes = MAX_RESP_SIZE;
936 }
937 cs->cbytes = cbytes;
938 gigaset_dbg_buffer(DEBUG_TRANSCMD, "received response",
939 cbytes, cs->respdata);
940 gigaset_handle_modem_response(cs);
941 cbytes = 0;
942
943 /* store EOL byte for CRLF collapsing */
944 cs->respdata[0] = c;
945 break;
946 default:
947 /* append to line buffer if possible */
948 if (cbytes < MAX_RESP_SIZE)
949 cs->respdata[cbytes] = c;
950 cbytes++;
951 }
952 }
953
954 /* save state */
955 cs->cbytes = cbytes;
956 }
957
958
959 /* process a block of data received through the control channel
960 */
961 void gigaset_isoc_input(struct inbuf_t *inbuf)
962 {
963 struct cardstate *cs = inbuf->cs;
964 unsigned tail, head, numbytes;
965 unsigned char *src;
966
967 head = inbuf->head;
968 while (head != (tail = inbuf->tail)) {
969 gig_dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail);
970 if (head > tail)
971 tail = RBUFSIZE;
972 src = inbuf->data + head;
973 numbytes = tail - head;
974 gig_dbg(DEBUG_INTR, "processing %u bytes", numbytes);
975
976 if (cs->mstate == MS_LOCKED) {
977 gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response",
978 numbytes, src);
979 gigaset_if_receive(inbuf->cs, src, numbytes);
980 } else {
981 cmd_loop(src, numbytes, inbuf);
982 }
983
984 head += numbytes;
985 if (head == RBUFSIZE)
986 head = 0;
987 gig_dbg(DEBUG_INTR, "setting head to %u", head);
988 inbuf->head = head;
989 }
990 }
991
992
993 /* == data output ========================================================== */
994
995 /**
996 * gigaset_isoc_send_skb() - queue an skb for sending
997 * @bcs: B channel descriptor structure.
998 * @skb: data to send.
999 *
1000 * Called by LL to queue an skb for sending, and start transmission if
1001 * necessary.
1002 * Once the payload data has been transmitted completely, gigaset_skb_sent()
1003 * will be called with the skb's link layer header preserved.
1004 *
1005 * Return value:
1006 * number of bytes accepted for sending (skb->len) if ok,
1007 * error code < 0 (eg. -ENODEV) on error
1008 */
1009 int gigaset_isoc_send_skb(struct bc_state *bcs, struct sk_buff *skb)
1010 {
1011 int len = skb->len;
1012 unsigned long flags;
1013
1014 spin_lock_irqsave(&bcs->cs->lock, flags);
1015 if (!bcs->cs->connected) {
1016 spin_unlock_irqrestore(&bcs->cs->lock, flags);
1017 return -ENODEV;
1018 }
1019
1020 skb_queue_tail(&bcs->squeue, skb);
1021 gig_dbg(DEBUG_ISO, "%s: skb queued, qlen=%d",
1022 __func__, skb_queue_len(&bcs->squeue));
1023
1024 /* tasklet submits URB if necessary */
1025 tasklet_schedule(&bcs->hw.bas->sent_tasklet);
1026 spin_unlock_irqrestore(&bcs->cs->lock, flags);
1027
1028 return len; /* ok so far */
1029 }