diff options
Diffstat (limited to 'drivers/isdn/i4l/isdn_v110.c')
| -rw-r--r-- | drivers/isdn/i4l/isdn_v110.c | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/drivers/isdn/i4l/isdn_v110.c b/drivers/isdn/i4l/isdn_v110.c new file mode 100644 index 0000000..c5d02b6 --- /dev/null +++ b/drivers/isdn/i4l/isdn_v110.c @@ -0,0 +1,616 @@ +/* $Id: isdn_v110.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $ + * + * Linux ISDN subsystem, V.110 related functions (linklevel). + * + * Copyright by Thomas Pfeiffer (pfeiffer@pds.de) + * + * This software may be used and distributed according to the terms + * of the GNU General Public License, incorporated herein by reference. + * + */ + +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/delay.h> + +#include <linux/isdn.h> +#include "isdn_v110.h" + +#undef ISDN_V110_DEBUG + +char *isdn_v110_revision = "$Revision: 1.1.2.2 $"; + +#define V110_38400 255 +#define V110_19200 15 +#define V110_9600 3 + +/* + * The following data are precoded matrices, online and offline matrix + * for 9600, 19200 und 38400, respectively + */ +static unsigned char V110_OnMatrix_9600[] = +{0xfc, 0xfc, 0xfc, 0xfc, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, + 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, + 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, + 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd}; + +static unsigned char V110_OffMatrix_9600[] = +{0xfc, 0xfc, 0xfc, 0xfc, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; + +static unsigned char V110_OnMatrix_19200[] = +{0xf0, 0xf0, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, + 0xfd, 0xff, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7}; + +static unsigned char V110_OffMatrix_19200[] = +{0xf0, 0xf0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; + +static unsigned char V110_OnMatrix_38400[] = +{0x00, 0x7f, 0x7f, 0x7f, 0x7f, 0xfd, 0x7f, 0x7f, 0x7f, 0x7f}; + +static unsigned char V110_OffMatrix_38400[] = +{0x00, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xff}; + +/* + * FlipBits reorders sequences of keylen bits in one byte. + * E.g. source order 7654321 will be converted to 45670123 when keylen = 4, + * and to 67452301 when keylen = 2. This is necessary because ordering on + * the isdn line is the other way. + */ +static inline unsigned char +FlipBits(unsigned char c, int keylen) +{ + unsigned char b = c; + unsigned char bit = 128; + int i; + int j; + int hunks = (8 / keylen); + + c = 0; + for (i = 0; i < hunks; i++) { + for (j = 0; j < keylen; j++) { + if (b & (bit >> j)) + c |= bit >> (keylen - j - 1); + } + bit >>= keylen; + } + return c; +} + + +/* isdn_v110_open allocates and initializes private V.110 data + * structures and returns a pointer to these. + */ +static isdn_v110_stream * +isdn_v110_open(unsigned char key, int hdrlen, int maxsize) +{ + int i; + isdn_v110_stream *v; + + if ((v = kzalloc(sizeof(isdn_v110_stream), GFP_ATOMIC)) == NULL) + return NULL; + v->key = key; + v->nbits = 0; + for (i = 0; key & (1 << i); i++) + v->nbits++; + + v->nbytes = 8 / v->nbits; + v->decodelen = 0; + + switch (key) { + case V110_38400: + v->OnlineFrame = V110_OnMatrix_38400; + v->OfflineFrame = V110_OffMatrix_38400; + break; + case V110_19200: + v->OnlineFrame = V110_OnMatrix_19200; + v->OfflineFrame = V110_OffMatrix_19200; + break; + default: + v->OnlineFrame = V110_OnMatrix_9600; + v->OfflineFrame = V110_OffMatrix_9600; + break; + } + v->framelen = v->nbytes * 10; + v->SyncInit = 5; + v->introducer = 0; + v->dbit = 1; + v->b = 0; + v->skbres = hdrlen; + v->maxsize = maxsize - hdrlen; + if ((v->encodebuf = kmalloc(maxsize, GFP_ATOMIC)) == NULL) { + kfree(v); + return NULL; + } + return v; +} + +/* isdn_v110_close frees private V.110 data structures */ +void +isdn_v110_close(isdn_v110_stream * v) +{ + if (v == NULL) + return; +#ifdef ISDN_V110_DEBUG + printk(KERN_DEBUG "v110 close\n"); +#endif + kfree(v->encodebuf); + kfree(v); +} + + +/* + * ValidHeaderBytes return the number of valid bytes in v->decodebuf + */ +static int +ValidHeaderBytes(isdn_v110_stream * v) +{ + int i; + for (i = 0; (i < v->decodelen) && (i < v->nbytes); i++) + if ((v->decodebuf[i] & v->key) != 0) + break; + return i; +} + +/* + * SyncHeader moves the decodebuf ptr to the next valid header + */ +static void +SyncHeader(isdn_v110_stream * v) +{ + unsigned char *rbuf = v->decodebuf; + int len = v->decodelen; + + if (len == 0) + return; + for (rbuf++, len--; len > 0; len--, rbuf++) /* such den SyncHeader in buf ! */ + if ((*rbuf & v->key) == 0) /* erstes byte gefunden ? */ + break; /* jupp! */ + if (len) + memcpy(v->decodebuf, rbuf, len); + + v->decodelen = len; +#ifdef ISDN_V110_DEBUG + printk(KERN_DEBUG "isdn_v110: Header resync\n"); +#endif +} + +/* DecodeMatrix takes n (n>=1) matrices (v110 frames, 10 bytes) where + len is the number of matrix-lines. len must be a multiple of 10, i.e. + only complete matices must be given. + From these, netto data is extracted and returned in buf. The return-value + is the bytecount of the decoded data. + */ +static int +DecodeMatrix(isdn_v110_stream * v, unsigned char *m, int len, unsigned char *buf) +{ + int line = 0; + int buflen = 0; + int mbit = 64; + int introducer = v->introducer; + int dbit = v->dbit; + unsigned char b = v->b; + + while (line < len) { /* Are we done with all lines of the matrix? */ + if ((line % 10) == 0) { /* the 0. line of the matrix is always 0 ! */ + if (m[line] != 0x00) { /* not 0 ? -> error! */ +#ifdef ISDN_V110_DEBUG + printk(KERN_DEBUG "isdn_v110: DecodeMatrix, V110 Bad Header\n"); + /* returning now is not the right thing, though :-( */ +#endif + } + line++; /* next line of matrix */ + continue; + } else if ((line % 10) == 5) { /* in line 5 there's only e-bits ! */ + if ((m[line] & 0x70) != 0x30) { /* 011 has to be at the beginning! */ +#ifdef ISDN_V110_DEBUG + printk(KERN_DEBUG "isdn_v110: DecodeMatrix, V110 Bad 5th line\n"); + /* returning now is not the right thing, though :-( */ +#endif + } + line++; /* next line */ + continue; + } else if (!introducer) { /* every byte starts with 10 (stopbit, startbit) */ + introducer = (m[line] & mbit) ? 0 : 1; /* current bit of the matrix */ + next_byte: + if (mbit > 2) { /* was it the last bit in this line ? */ + mbit >>= 1; /* no -> take next */ + continue; + } /* otherwise start with leftmost bit in the next line */ + mbit = 64; + line++; + continue; + } else { /* otherwise we need to set a data bit */ + if (m[line] & mbit) /* was that bit set in the matrix ? */ + b |= dbit; /* yes -> set it in the data byte */ + else + b &= dbit - 1; /* no -> clear it in the data byte */ + if (dbit < 128) /* is that data byte done ? */ + dbit <<= 1; /* no, got the next bit */ + else { /* data byte is done */ + buf[buflen++] = b; /* copy byte into the output buffer */ + introducer = b = 0; /* init of the intro sequence and of the data byte */ + dbit = 1; /* next we look for the 0th bit */ + } + goto next_byte; /* look for next bit in the matrix */ + } + } + v->introducer = introducer; + v->dbit = dbit; + v->b = b; + return buflen; /* return number of bytes in the output buffer */ +} + +/* + * DecodeStream receives V.110 coded data from the input stream. It recovers the + * original frames. + * The input stream doesn't need to be framed + */ +struct sk_buff * +isdn_v110_decode(isdn_v110_stream * v, struct sk_buff *skb) +{ + int i; + int j; + int len; + unsigned char *v110_buf; + unsigned char *rbuf; + + if (!skb) { + printk(KERN_WARNING "isdn_v110_decode called with NULL skb!\n"); + return NULL; + } + rbuf = skb->data; + len = skb->len; + if (v == NULL) { + /* invalid handle, no chance to proceed */ + printk(KERN_WARNING "isdn_v110_decode called with NULL stream!\n"); + dev_kfree_skb(skb); + return NULL; + } + if (v->decodelen == 0) /* cache empty? */ + for (; len > 0; len--, rbuf++) /* scan for SyncHeader in buf */ + if ((*rbuf & v->key) == 0) + break; /* found first byte */ + if (len == 0) { + dev_kfree_skb(skb); + return NULL; + } + /* copy new data to decode-buffer */ + memcpy(&(v->decodebuf[v->decodelen]), rbuf, len); + v->decodelen += len; + ReSync: + if (v->decodelen < v->nbytes) { /* got a new header ? */ + dev_kfree_skb(skb); + return NULL; /* no, try later */ + } + if (ValidHeaderBytes(v) != v->nbytes) { /* is that a valid header? */ + SyncHeader(v); /* no -> look for header */ + goto ReSync; + } + len = (v->decodelen - (v->decodelen % (10 * v->nbytes))) / v->nbytes; + if ((v110_buf = kmalloc(len, GFP_ATOMIC)) == NULL) { + printk(KERN_WARNING "isdn_v110_decode: Couldn't allocate v110_buf\n"); + dev_kfree_skb(skb); + return NULL; + } + for (i = 0; i < len; i++) { + v110_buf[i] = 0; + for (j = 0; j < v->nbytes; j++) + v110_buf[i] |= (v->decodebuf[(i * v->nbytes) + j] & v->key) << (8 - ((j + 1) * v->nbits)); + v110_buf[i] = FlipBits(v110_buf[i], v->nbits); + } + v->decodelen = (v->decodelen % (10 * v->nbytes)); + memcpy(v->decodebuf, &(v->decodebuf[len * v->nbytes]), v->decodelen); + + skb_trim(skb, DecodeMatrix(v, v110_buf, len, skb->data)); + kfree(v110_buf); + if (skb->len) + return skb; + else { + kfree_skb(skb); + return NULL; + } +} + +/* EncodeMatrix takes input data in buf, len is the bytecount. + Data is encoded into v110 frames in m. Return value is the number of + matrix-lines generated. + */ +static int +EncodeMatrix(unsigned char *buf, int len, unsigned char *m, int mlen) +{ + int line = 0; + int i = 0; + int mbit = 128; + int dbit = 1; + int introducer = 3; + int ibit[] = {0, 1, 1}; + + while ((i < len) && (line < mlen)) { /* while we still have input data */ + switch (line % 10) { /* in which line of the matrix are we? */ + case 0: + m[line++] = 0x00; /* line 0 is always 0 */ + mbit = 128; /* go on with the 7th bit */ + break; + case 5: + m[line++] = 0xbf; /* line 5 is always 10111111 */ + mbit = 128; /* go on with the 7th bit */ + break; + } + if (line >= mlen) { + printk(KERN_WARNING "isdn_v110 (EncodeMatrix): buffer full!\n"); + return line; + } + next_bit: + switch (mbit) { /* leftmost or rightmost bit ? */ + case 1: + line++; /* rightmost -> go to next line */ + if (line >= mlen) { + printk(KERN_WARNING "isdn_v110 (EncodeMatrix): buffer full!\n"); + return line; + } + case 128: + m[line] = 128; /* leftmost -> set byte to 1000000 */ + mbit = 64; /* current bit in the matrix line */ + continue; + } + if (introducer) { /* set 110 sequence ? */ + introducer--; /* set on digit less */ + m[line] |= ibit[introducer] ? mbit : 0; /* set corresponding bit */ + mbit >>= 1; /* bit of matrix line >> 1 */ + goto next_bit; /* and go on there */ + } /* else push data bits into the matrix! */ + m[line] |= (buf[i] & dbit) ? mbit : 0; /* set data bit in matrix */ + if (dbit == 128) { /* was it the last one? */ + dbit = 1; /* then go on with first bit of */ + i++; /* next byte in input buffer */ + if (i < len) /* input buffer done ? */ + introducer = 3; /* no, write introducer 110 */ + else { /* input buffer done ! */ + m[line] |= (mbit - 1) & 0xfe; /* set remaining bits in line to 1 */ + break; + } + } else /* not the last data bit */ + dbit <<= 1; /* then go to next data bit */ + mbit >>= 1; /* go to next bit of matrix */ + goto next_bit; + + } + /* if necessary, generate remaining lines of the matrix... */ + if ((line) && ((line + 10) < mlen)) + switch (++line % 10) { + case 1: + m[line++] = 0xfe; + case 2: + m[line++] = 0xfe; + case 3: + m[line++] = 0xfe; + case 4: + m[line++] = 0xfe; + case 5: + m[line++] = 0xbf; + case 6: + m[line++] = 0xfe; + case 7: + m[line++] = 0xfe; + case 8: + m[line++] = 0xfe; + case 9: + m[line++] = 0xfe; + } + return line; /* that's how many lines we have */ +} + +/* + * Build a sync frame. + */ +static struct sk_buff * +isdn_v110_sync(isdn_v110_stream *v) +{ + struct sk_buff *skb; + + if (v == NULL) { + /* invalid handle, no chance to proceed */ + printk(KERN_WARNING "isdn_v110_sync called with NULL stream!\n"); + return NULL; + } + if ((skb = dev_alloc_skb(v->framelen + v->skbres))) { + skb_reserve(skb, v->skbres); + memcpy(skb_put(skb, v->framelen), v->OfflineFrame, v->framelen); + } + return skb; +} + +/* + * Build an idle frame. + */ +static struct sk_buff * +isdn_v110_idle(isdn_v110_stream *v) +{ + struct sk_buff *skb; + + if (v == NULL) { + /* invalid handle, no chance to proceed */ + printk(KERN_WARNING "isdn_v110_sync called with NULL stream!\n"); + return NULL; + } + if ((skb = dev_alloc_skb(v->framelen + v->skbres))) { + skb_reserve(skb, v->skbres); + memcpy(skb_put(skb, v->framelen), v->OnlineFrame, v->framelen); + } + return skb; +} + +struct sk_buff * +isdn_v110_encode(isdn_v110_stream * v, struct sk_buff *skb) +{ + int i; + int j; + int rlen; + int mlen; + int olen; + int size; + int sval1; + int sval2; + int nframes; + unsigned char *v110buf; + unsigned char *rbuf; + struct sk_buff *nskb; + + if (v == NULL) { + /* invalid handle, no chance to proceed */ + printk(KERN_WARNING "isdn_v110_encode called with NULL stream!\n"); + return NULL; + } + if (!skb) { + /* invalid skb, no chance to proceed */ + printk(KERN_WARNING "isdn_v110_encode called with NULL skb!\n"); + return NULL; + } + rlen = skb->len; + nframes = (rlen + 3) / 4; + v110buf = v->encodebuf; + if ((nframes * 40) > v->maxsize) { + size = v->maxsize; + rlen = v->maxsize / 40; + } else + size = nframes * 40; + if (!(nskb = dev_alloc_skb(size + v->skbres + sizeof(int)))) { + printk(KERN_WARNING "isdn_v110_encode: Couldn't alloc skb\n"); + return NULL; + } + skb_reserve(nskb, v->skbres + sizeof(int)); + if (skb->len == 0) { + memcpy(skb_put(nskb, v->framelen), v->OnlineFrame, v->framelen); + *((int *)skb_push(nskb, sizeof(int))) = 0; + return nskb; + } + mlen = EncodeMatrix(skb->data, rlen, v110buf, size); + /* now distribute 2 or 4 bits each to the output stream! */ + rbuf = skb_put(nskb, size); + olen = 0; + sval1 = 8 - v->nbits; + sval2 = v->key << sval1; + for (i = 0; i < mlen; i++) { + v110buf[i] = FlipBits(v110buf[i], v->nbits); + for (j = 0; j < v->nbytes; j++) { + if (size--) + *rbuf++ = ~v->key | (((v110buf[i] << (j * v->nbits)) & sval2) >> sval1); + else { + printk(KERN_WARNING "isdn_v110_encode: buffers full!\n"); + goto buffer_full; + } + olen++; + } + } +buffer_full: + skb_trim(nskb, olen); + *((int *)skb_push(nskb, sizeof(int))) = rlen; + return nskb; +} + +int +isdn_v110_stat_callback(int idx, isdn_ctrl *c) +{ + isdn_v110_stream *v = NULL; + int i; + int ret = 0; + + if (idx < 0) + return 0; + switch (c->command) { + case ISDN_STAT_BSENT: + /* Keep the send-queue of the driver filled + * with frames: + * If number of outstanding frames < 3, + * send down an Idle-Frame (or an Sync-Frame, if + * v->SyncInit != 0). + */ + if (!(v = dev->v110[idx])) + return 0; + atomic_inc(&dev->v110use[idx]); + for (i=0; i * v->framelen < c->parm.length; i++) { + if (v->skbidle > 0) { + v->skbidle--; + ret = 1; + } else { + if (v->skbuser > 0) + v->skbuser--; + ret = 0; + } + } + for (i = v->skbuser + v->skbidle; i < 2; i++) { + struct sk_buff *skb; + if (v->SyncInit > 0) + skb = isdn_v110_sync(v); + else + skb = isdn_v110_idle(v); + if (skb) { + if (dev->drv[c->driver]->interface->writebuf_skb(c->driver, c->arg, 1, skb) <= 0) { + dev_kfree_skb(skb); + break; + } else { + if (v->SyncInit) + v->SyncInit--; + v->skbidle++; + } + } else + break; + } + atomic_dec(&dev->v110use[idx]); + return ret; + case ISDN_STAT_DHUP: + case ISDN_STAT_BHUP: + while (1) { + atomic_inc(&dev->v110use[idx]); + if (atomic_dec_and_test(&dev->v110use[idx])) { + isdn_v110_close(dev->v110[idx]); + dev->v110[idx] = NULL; + break; + } + mdelay(1); + } + break; + case ISDN_STAT_BCONN: + if (dev->v110emu[idx] && (dev->v110[idx] == NULL)) { + int hdrlen = dev->drv[c->driver]->interface->hl_hdrlen; + int maxsize = dev->drv[c->driver]->interface->maxbufsize; + atomic_inc(&dev->v110use[idx]); + switch (dev->v110emu[idx]) { + case ISDN_PROTO_L2_V11096: + dev->v110[idx] = isdn_v110_open(V110_9600, hdrlen, maxsize); + break; + case ISDN_PROTO_L2_V11019: + dev->v110[idx] = isdn_v110_open(V110_19200, hdrlen, maxsize); + break; + case ISDN_PROTO_L2_V11038: + dev->v110[idx] = isdn_v110_open(V110_38400, hdrlen, maxsize); + break; + default:; + } + if ((v = dev->v110[idx])) { + while (v->SyncInit) { + struct sk_buff *skb = isdn_v110_sync(v); + if (dev->drv[c->driver]->interface->writebuf_skb(c->driver, c->arg, 1, skb) <= 0) { + dev_kfree_skb(skb); + /* Unable to send, try later */ + break; + } + v->SyncInit--; + v->skbidle++; + } + } else + printk(KERN_WARNING "isdn_v110: Couldn't open stream for chan %d\n", idx); + atomic_dec(&dev->v110use[idx]); + } + break; + default: + return 0; + } + return 0; +} |
