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authorKarsten Keil <keil@b1-systems.de>2009-07-08 20:31:42 +0200
committerKarsten Keil <keil@b1-systems.de>2009-07-25 20:16:01 +0200
commitc38fc3bc2ecddd4f5278131603e6964cbed071b2 (patch)
tree3821cf2fc6226375bbbf8c338316eef33f5b899d /drivers/isdn/i4l
parent6bd4bcd3cd8affc09eaee7efbc037f65f4a71501 (diff)
downloadblackbird-op-linux-c38fc3bc2ecddd4f5278131603e6964cbed071b2.tar.gz
blackbird-op-linux-c38fc3bc2ecddd4f5278131603e6964cbed071b2.zip
ISDN: Add support for none reverse bitstreams to isdnhdc
The original isdnhdlc code was developed for devices which had reversed bitorder in the byte stream. Adding code to handle normal bitstreams as well. Signed-off-by: Karsten Keil <keil@b1-systems.de>
Diffstat (limited to 'drivers/isdn/i4l')
-rw-r--r--drivers/isdn/i4l/isdnhdlc.c70
1 files changed, 35 insertions, 35 deletions
diff --git a/drivers/isdn/i4l/isdnhdlc.c b/drivers/isdn/i4l/isdnhdlc.c
index b80e55ab8914..df345ce73f48 100644
--- a/drivers/isdn/i4l/isdnhdlc.c
+++ b/drivers/isdn/i4l/isdnhdlc.c
@@ -2,6 +2,7 @@
* isdnhdlc.c -- General purpose ISDN HDLC decoder.
*
* Copyright (C)
+ * 2009 Karsten Keil <keil@b1-systems.de>
* 2002 Wolfgang Mües <wolfgang@iksw-muees.de>
* 2001 Frode Isaksen <fisaksen@bewan.com>
* 2001 Kai Germaschewski <kai.germaschewski@gmx.de>
@@ -25,6 +26,7 @@
#include <linux/init.h>
#include <linux/crc-ccitt.h>
#include <linux/isdn/hdlc.h>
+#include <linux/bitrev.h>
/*-------------------------------------------------------------------*/
@@ -48,35 +50,21 @@ enum {
HDLC_SENDFLAG_B1A6, HDLC_SENDFLAG_B7, STOPPED
};
-void isdnhdlc_rcv_init(struct isdnhdlc_vars *hdlc, int do_adapt56)
+void isdnhdlc_rcv_init(struct isdnhdlc_vars *hdlc, u32 features)
{
- hdlc->bit_shift = 0;
- hdlc->hdlc_bits1 = 0;
- hdlc->data_bits = 0;
- hdlc->ffbit_shift = 0;
- hdlc->data_received = 0;
+ memset(hdlc, 0, sizeof(struct isdnhdlc_vars));
hdlc->state = HDLC_GET_DATA;
- hdlc->do_adapt56 = do_adapt56;
- hdlc->dchannel = 0;
- hdlc->crc = 0;
- hdlc->cbin = 0;
- hdlc->shift_reg = 0;
- hdlc->ffvalue = 0;
- hdlc->dstpos = 0;
+ if (features & HDLC_56KBIT)
+ hdlc->do_adapt56 = 1;
+ if (features & HDLC_BITREVERSE)
+ hdlc->do_bitreverse = 1;
}
EXPORT_SYMBOL(isdnhdlc_out_init);
-void isdnhdlc_out_init(struct isdnhdlc_vars *hdlc, int is_d_channel,
- int do_adapt56)
+void isdnhdlc_out_init(struct isdnhdlc_vars *hdlc, u32 features)
{
- hdlc->bit_shift = 0;
- hdlc->hdlc_bits1 = 0;
- hdlc->data_bits = 0;
- hdlc->ffbit_shift = 0;
- hdlc->data_received = 0;
- hdlc->do_closing = 0;
- hdlc->ffvalue = 0;
- if (is_d_channel) {
+ memset(hdlc, 0, sizeof(struct isdnhdlc_vars));
+ if (features & HDLC_DCHANNEL) {
hdlc->dchannel = 1;
hdlc->state = HDLC_SEND_FIRST_FLAG;
} else {
@@ -85,16 +73,13 @@ void isdnhdlc_out_init(struct isdnhdlc_vars *hdlc, int is_d_channel,
hdlc->ffvalue = 0x7e;
}
hdlc->cbin = 0x7e;
- hdlc->bit_shift = 0;
- if (do_adapt56) {
+ if (features & HDLC_56KBIT) {
hdlc->do_adapt56 = 1;
- hdlc->data_bits = 0;
hdlc->state = HDLC_SENDFLAG_B0;
- } else {
- hdlc->do_adapt56 = 0;
+ } else
hdlc->data_bits = 8;
- }
- hdlc->shift_reg = 0;
+ if (features & HDLC_BITREVERSE)
+ hdlc->do_bitreverse = 1;
}
EXPORT_SYMBOL(isdnhdlc_rcv_init);
@@ -188,7 +173,11 @@ int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src, int slen,
while (slen > 0) {
if (hdlc->bit_shift == 0) {
- hdlc->cbin = *src++;
+ /* the code is for bitreverse streams */
+ if (hdlc->do_bitreverse == 0)
+ hdlc->cbin = bitrev8(*src++);
+ else
+ hdlc->cbin = *src++;
slen--;
hdlc->bit_shift = 8;
if (hdlc->do_adapt56)
@@ -405,12 +394,15 @@ int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src, u16 slen,
case STOPPED:
while (dsize--)
*dst++ = 0xff;
-
return dsize;
case HDLC_SEND_FAST_FLAG:
hdlc->do_closing = 0;
if (slen == 0) {
- *dst++ = hdlc->ffvalue;
+ /* the code is for bitreverse streams */
+ if (hdlc->do_bitreverse == 0)
+ *dst++ = bitrev8(hdlc->ffvalue);
+ else
+ *dst++ = hdlc->ffvalue;
len++;
dsize--;
break;
@@ -594,7 +586,11 @@ int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src, u16 slen,
hdlc->cbin = 0x7e;
hdlc->state = HDLC_SEND_FIRST_FLAG;
} else {
- *dst++ = hdlc->cbin;
+ /* the code is for bitreverse streams */
+ if (hdlc->do_bitreverse == 0)
+ *dst++ = bitrev8(hdlc->cbin);
+ else
+ *dst++ = hdlc->cbin;
hdlc->bit_shift = 0;
hdlc->data_bits = 0;
len++;
@@ -612,7 +608,11 @@ int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src, u16 slen,
}
}
if (hdlc->data_bits == 8) {
- *dst++ = hdlc->cbin;
+ /* the code is for bitreverse streams */
+ if (hdlc->do_bitreverse == 0)
+ *dst++ = bitrev8(hdlc->cbin);
+ else
+ *dst++ = hdlc->cbin;
hdlc->data_bits = 0;
len++;
dsize--;
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