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Diffstat (limited to 'drivers/isdn/hardware/mISDN/isdnhdlc.h')
-rw-r--r--drivers/isdn/hardware/mISDN/isdnhdlc.h69
1 files changed, 69 insertions, 0 deletions
diff --git a/drivers/isdn/hardware/mISDN/isdnhdlc.h b/drivers/isdn/hardware/mISDN/isdnhdlc.h
new file mode 100644
index 000000000000..fe2c1279c139
--- /dev/null
+++ b/drivers/isdn/hardware/mISDN/isdnhdlc.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * hdlc.h -- General purpose ISDN HDLC decoder.
+ *
+ * Implementation of a HDLC decoder/encoder in software.
+ * Necessary because some ISDN devices don't have HDLC
+ * controllers.
+ *
+ * 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>
+ */
+
+#ifndef __ISDNHDLC_H__
+#define __ISDNHDLC_H__
+
+struct isdnhdlc_vars {
+ int bit_shift;
+ int hdlc_bits1;
+ int data_bits;
+ int ffbit_shift; /* encoding only */
+ int state;
+ int dstpos;
+
+ u16 crc;
+
+ u8 cbin;
+ u8 shift_reg;
+ u8 ffvalue;
+
+ /* set if transferring data */
+ u32 data_received:1;
+ /* set if D channel (send idle instead of flags) */
+ u32 dchannel:1;
+ /* set if 56K adaptation */
+ u32 do_adapt56:1;
+ /* set if in closing phase (need to send CRC + flag) */
+ u32 do_closing:1;
+ /* set if data is bitreverse */
+ u32 do_bitreverse:1;
+};
+
+/* Feature Flags */
+#define HDLC_56KBIT 0x01
+#define HDLC_DCHANNEL 0x02
+#define HDLC_BITREVERSE 0x04
+
+/*
+ The return value from isdnhdlc_decode is
+ the frame length, 0 if no complete frame was decoded,
+ or a negative error number
+*/
+#define HDLC_FRAMING_ERROR 1
+#define HDLC_CRC_ERROR 2
+#define HDLC_LENGTH_ERROR 3
+
+extern void isdnhdlc_rcv_init(struct isdnhdlc_vars *hdlc, u32 features);
+
+extern int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src,
+ int slen, int *count, u8 *dst, int dsize);
+
+extern void isdnhdlc_out_init(struct isdnhdlc_vars *hdlc, u32 features);
+
+extern int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src,
+ u16 slen, int *count, u8 *dst, int dsize);
+
+#endif /* __ISDNHDLC_H__ */