isdn: move capi drivers to staging

I tried to find any indication of whether the capi drivers are still in
use, and have not found anything from a long time ago.

With public ISDN networks almost completely shut down over the past 12
months, there is very little you can actually do with this hardware. The
main remaining use case would be to connect ISDN voice phones to an
in-house installation with Asterisk or LCR, but anyone trying this in
turn seems to be using either the mISDN driver stack, or out-of-tree
drivers from the hardware vendors.

I may of course have missed something, so I would suggest moving these
three drivers (avm, hysdn, gigaset) into drivers/staging/ just in case
someone still uses them.

If nobody complains, we can remove them entirely in six months, or
otherwise move the core code and any drivers that are still needed back
into drivers/isdn.

As Paul Bolle notes, he is still testing the gigaset driver as long as
he can, but the Dutch ISDN network will be shut down in September 2019,
which puts an end to that.

Marcel Holtmann still maintains the Bluetooth CMTP profile and wants to
keep that alive, so the actual CAPI subsystem code remains in place for
now, after all other drivers are gone, CMTP and CAPI can be merged into
a single driver directory.

Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

14 files changed, 13312 insertions, 0 deletions

diff --git a/drivers/staging/isdn/gigaset/Kconfig b/drivers/staging/isdn/gigaset/Kconfig
new file mode 100644
index 000000000000..c593105b3600
--- /dev/null
+++ b/drivers/staging/isdn/gigaset/Kconfig
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig ISDN_DRV_GIGASET
+	tristate "Siemens Gigaset support"
+	depends on TTY
+	select CRC_CCITT
+	select BITREVERSE
+	help
+	  This driver supports the Siemens Gigaset SX205/255 family of
+	  ISDN DECT bases, including the predecessors Gigaset 3070/3075
+	  and 4170/4175 and their T-Com versions Sinus 45isdn and Sinus
+	  721X.
+	  If you have one of these devices, say M here and for at least
+	  one of the connection specific parts that follow.
+	  This will build a module called "gigaset".
+	  Note: If you build your ISDN subsystem (ISDN_CAPI or ISDN_I4L)
+	  as a module, you have to build this driver as a module too,
+	  otherwise the Gigaset device won't show up as an ISDN device.
+
+if ISDN_DRV_GIGASET
+
+config GIGASET_CAPI
+	bool "Gigaset CAPI support"
+	depends on ISDN_CAPI='y'||(ISDN_CAPI='m'&&ISDN_DRV_GIGASET='m')
+	default 'y'
+	help
+	  Build the Gigaset driver as a CAPI 2.0 driver interfacing with
+	  the Kernel CAPI subsystem. To use it with the old ISDN4Linux
+	  subsystem you'll have to enable the capidrv glue driver.
+	  (select ISDN_CAPI_CAPIDRV.)
+	  Say N to build the old native ISDN4Linux variant.
+	  If unsure, say Y.
+
+config GIGASET_BASE
+	tristate "Gigaset base station support"
+	depends on USB
+	help
+	  Say M here if you want to use the USB interface of the Gigaset
+	  base for connection to your system.
+	  This will build a module called "bas_gigaset".
+
+config GIGASET_M105
+	tristate "Gigaset M105 support"
+	depends on USB
+	help
+	  Say M here if you want to connect to the Gigaset base via DECT
+	  using a Gigaset M105 (Sinus 45 Data 2) USB DECT device.
+	  This will build a module called "usb_gigaset".
+
+config GIGASET_M101
+	tristate "Gigaset M101 support"
+	help
+	  Say M here if you want to connect to the Gigaset base via DECT
+	  using a Gigaset M101 (Sinus 45 Data 1) RS232 DECT device.
+	  This will build a module called "ser_gigaset".
+
+config GIGASET_DEBUG
+	bool "Gigaset debugging"
+	help
+	  This enables debugging code in the Gigaset drivers.
+	  If in doubt, say yes.
+
+endif # ISDN_DRV_GIGASET
diff --git a/drivers/staging/isdn/gigaset/Makefile b/drivers/staging/isdn/gigaset/Makefile
new file mode 100644
index 000000000000..9c010891dcd7
--- /dev/null
+++ b/drivers/staging/isdn/gigaset/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+gigaset-y := common.o interface.o proc.o ev-layer.o asyncdata.o
+
+ifdef CONFIG_GIGASET_CAPI
+gigaset-y += capi.o
+else
+gigaset-y += dummyll.o
+endif
+
+usb_gigaset-y := usb-gigaset.o
+ser_gigaset-y := ser-gigaset.o
+bas_gigaset-y := bas-gigaset.o isocdata.o
+
+obj-$(CONFIG_ISDN_DRV_GIGASET) += gigaset.o
+obj-$(CONFIG_GIGASET_M105) += usb_gigaset.o
+obj-$(CONFIG_GIGASET_BASE) += bas_gigaset.o
+obj-$(CONFIG_GIGASET_M101) += ser_gigaset.o
diff --git a/drivers/staging/isdn/gigaset/asyncdata.c b/drivers/staging/isdn/gigaset/asyncdata.c
new file mode 100644
index 000000000000..c0cbee06bc21
--- /dev/null
+++ b/drivers/staging/isdn/gigaset/asyncdata.c
@@ -0,0 +1,609 @@
+/*
+ * Common data handling layer for ser_gigaset and usb_gigaset
+ *
+ * Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>,
+ *                       Hansjoerg Lipp <hjlipp@web.de>,
+ *                       Stefan Eilers.
+ *
+ * =====================================================================
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License as
+ *	published by the Free Software Foundation; either version 2 of
+ *	the License, or (at your option) any later version.
+ * =====================================================================
+ */
+
+#include "gigaset.h"
+#include <linux/crc-ccitt.h>
+#include <linux/bitrev.h>
+#include <linux/export.h>
+
+/* check if byte must be stuffed/escaped
+ * I'm not sure which data should be encoded.
+ * Therefore I will go the hard way and encode every value
+ * less than 0x20, the flag sequence and the control escape char.
+ */
+static inline int muststuff(unsigned char c)
+{
+	if (c < PPP_TRANS) return 1;
+	if (c == PPP_FLAG) return 1;
+	if (c == PPP_ESCAPE) return 1;
+	/* other possible candidates: */
+	/* 0x91: XON with parity set */
+	/* 0x93: XOFF with parity set */
+	return 0;
+}
+
+/* == data input =========================================================== */
+
+/* process a block of received bytes in command mode
+ * (mstate != MS_LOCKED && (inputstate & INS_command))
+ * Append received bytes to the command response buffer and forward them
+ * line by line to the response handler. Exit whenever a mode/state change
+ * might have occurred.
+ * Note: Received lines may be terminated by CR, LF, or CR LF, which will be
+ * removed before passing the line to the response handler.
+ * Return value:
+ *	number of processed bytes
+ */
+static unsigned cmd_loop(unsigned numbytes, struct inbuf_t *inbuf)
+{
+	unsigned char *src = inbuf->data + inbuf->head;
+	struct cardstate *cs = inbuf->cs;
+	unsigned cbytes = cs->cbytes;
+	unsigned procbytes = 0;
+	unsigned char c;
+
+	while (procbytes < numbytes) {
+		c = *src++;
+		procbytes++;
+
+		switch (c) {
+		case '\n':
+			if (cbytes == 0 && cs->respdata[0] == '\r') {
+				/* collapse LF with preceding CR */
+				cs->respdata[0] = 0;
+				break;
+			}
+			/* fall through */
+		case '\r':
+			/* end of message line, pass to response handler */
+			if (cbytes >= MAX_RESP_SIZE) {
+				dev_warn(cs->dev, "response too large (%d)\n",
+					 cbytes);
+				cbytes = MAX_RESP_SIZE;
+			}
+			cs->cbytes = cbytes;
+			gigaset_dbg_buffer(DEBUG_TRANSCMD, "received response",
+					   cbytes, cs->respdata);
+			gigaset_handle_modem_response(cs);
+			cbytes = 0;
+
+			/* store EOL byte for CRLF collapsing */
+			cs->respdata[0] = c;
+
+			/* cs->dle may have changed */
+			if (cs->dle && !(inbuf->inputstate & INS_DLE_command))
+				inbuf->inputstate &= ~INS_command;
+
+			/* return for reevaluating state */
+			goto exit;
+
+		case DLE_FLAG:
+			if (inbuf->inputstate & INS_DLE_char) {
+				/* quoted DLE: clear quote flag */
+				inbuf->inputstate &= ~INS_DLE_char;
+			} else if (cs->dle ||
+				   (inbuf->inputstate & INS_DLE_command)) {
+				/* DLE escape, pass up for handling */
+				inbuf->inputstate |= INS_DLE_char;
+				goto exit;
+			}
+			/* quoted or not in DLE mode: treat as regular data */
+			/* fall through */
+		default:
+			/* append to line buffer if possible */
+			if (cbytes < MAX_RESP_SIZE)
+				cs->respdata[cbytes] = c;
+			cbytes++;
+		}
+	}
+exit:
+	cs->cbytes = cbytes;
+	return procbytes;
+}
+
+/* process a block of received bytes in lock mode
+ * All received bytes are passed unmodified to the tty i/f.
+ * Return value:
+ *	number of processed bytes
+ */
+static unsigned lock_loop(unsigned numbytes, struct inbuf_t *inbuf)
+{
+	unsigned char *src = inbuf->data + inbuf->head;
+
+	gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response", numbytes, src);
+	gigaset_if_receive(inbuf->cs, src, numbytes);
+	return numbytes;
+}
+
+/* process a block of received bytes in HDLC data mode
+ * (mstate != MS_LOCKED && !(inputstate & INS_command) && proto2 == L2_HDLC)
+ * Collect HDLC frames, undoing byte stuffing and watching for DLE escapes.
+ * When a frame is complete, check the FCS and pass valid frames to the LL.
+ * If DLE is encountered, return immediately to let the caller handle it.
+ * Return value:
+ *	number of processed bytes
+ */
+static unsigned hdlc_loop(unsigned numbytes, struct inbuf_t *inbuf)
+{
+	struct cardstate *cs = inbuf->cs;
+	struct bc_state *bcs = cs->bcs;
+	int inputstate = bcs->inputstate;
+	__u16 fcs = bcs->rx_fcs;
+	struct sk_buff *skb = bcs->rx_skb;
+	unsigned char *src = inbuf->data + inbuf->head;
+	unsigned procbytes = 0;
+	unsigned char c;
+
+	if (inputstate & INS_byte_stuff) {
+		if (!numbytes)
+			return 0;
+		inputstate &= ~INS_byte_stuff;
+		goto byte_stuff;
+	}
+
+	while (procbytes < numbytes) {
+		c = *src++;
+		procbytes++;
+		if (c == DLE_FLAG) {
+			if (inputstate & INS_DLE_char) {
+				/* quoted DLE: clear quote flag */
+				inputstate &= ~INS_DLE_char;
+			} else if (cs->dle || (inputstate & INS_DLE_command)) {
+				/* DLE escape, pass up for handling */
+				inputstate |= INS_DLE_char;
+				break;
+			}
+		}
+
+		if (c == PPP_ESCAPE) {
+			/* byte stuffing indicator: pull in next byte */
+			if (procbytes >= numbytes) {
+				/* end of buffer, save for later processing */
+				inputstate |= INS_byte_stuff;
+				break;
+			}
+byte_stuff:
+			c = *src++;
+			procbytes++;
+			if (c == DLE_FLAG) {
+				if (inputstate & INS_DLE_char) {
+					/* quoted DLE: clear quote flag */
+					inputstate &= ~INS_DLE_char;
+				} else if (cs->dle ||
+					   (inputstate & INS_DLE_command)) {
+					/* DLE escape, pass up for handling */
+					inputstate |=
+						INS_DLE_char | INS_byte_stuff;
+					break;
+				}
+			}
+			c ^= PPP_TRANS;
+#ifdef CONFIG_GIGASET_DEBUG
+			if (!muststuff(c))
+				gig_dbg(DEBUG_HDLC, "byte stuffed: 0x%02x", c);
+#endif
+		} else if (c == PPP_FLAG) {
+			/* end of frame: process content if any */
+			if (inputstate & INS_have_data) {
+				gig_dbg(DEBUG_HDLC,
+					"7e----------------------------");
+
+				/* check and pass received frame */
+				if (!skb) {
+					/* skipped frame */
+					gigaset_isdn_rcv_err(bcs);
+				} else if (skb->len < 2) {
+					/* frame too short for FCS */
+					dev_warn(cs->dev,
+						 "short frame (%d)\n",
+						 skb->len);
+					gigaset_isdn_rcv_err(bcs);
+					dev_kfree_skb_any(skb);
+				} else if (fcs != PPP_GOODFCS) {
+					/* frame check error */
+					dev_err(cs->dev,
+						"Checksum failed, %u bytes corrupted!\n",
+						skb->len);
+					gigaset_isdn_rcv_err(bcs);
+					dev_kfree_skb_any(skb);
+				} else {
+					/* good frame */
+					__skb_trim(skb, skb->len - 2);
+					gigaset_skb_rcvd(bcs, skb);
+				}
+
+				/* prepare reception of next frame */
+				inputstate &= ~INS_have_data;
+				skb = gigaset_new_rx_skb(bcs);
+			} else {
+				/* empty frame (7E 7E) */
+#ifdef CONFIG_GIGASET_DEBUG
+				++bcs->emptycount;
+#endif
+				if (!skb) {
+					/* skipped (?) */
+					gigaset_isdn_rcv_err(bcs);
+					skb = gigaset_new_rx_skb(bcs);
+				}
+			}
+
+			fcs = PPP_INITFCS;
+			continue;
+#ifdef CONFIG_GIGASET_DEBUG
+		} else if (muststuff(c)) {
+			/* Should not happen. Possible after ZDLE=1<CR><LF>. */
+			gig_dbg(DEBUG_HDLC, "not byte stuffed: 0x%02x", c);
+#endif
+		}
+
+		/* regular data byte, append to skb */
+#ifdef CONFIG_GIGASET_DEBUG
+		if (!(inputstate & INS_have_data)) {
+			gig_dbg(DEBUG_HDLC, "7e (%d x) ================",
+				bcs->emptycount);
+			bcs->emptycount = 0;
+		}
+#endif
+		inputstate |= INS_have_data;
+		if (skb) {
+			if (skb->len >= bcs->rx_bufsize) {
+				dev_warn(cs->dev, "received packet too long\n");
+				dev_kfree_skb_any(skb);
+				/* skip remainder of packet */
+				bcs->rx_skb = skb = NULL;
+			} else {
+				__skb_put_u8(skb, c);
+				fcs = crc_ccitt_byte(fcs, c);
+			}
+		}
+	}
+
+	bcs->inputstate = inputstate;
+	bcs->rx_fcs = fcs;
+	return procbytes;
+}
+
+/* process a block of received bytes in transparent data mode
+ * (mstate != MS_LOCKED && !(inputstate & INS_command) && proto2 != L2_HDLC)
+ * Invert bytes, undoing byte stuffing and watching for DLE escapes.
+ * If DLE is encountered, return immediately to let the caller handle it.
+ * Return value:
+ *	number of processed bytes
+ */
+static unsigned iraw_loop(unsigned numbytes, struct inbuf_t *inbuf)
+{
+	struct cardstate *cs = inbuf->cs;
+	struct bc_state *bcs = cs->bcs;
+	int inputstate = bcs->inputstate;
+	struct sk_buff *skb = bcs->rx_skb;
+	unsigned char *src = inbuf->data + inbuf->head;
+	unsigned procbytes = 0;
+	unsigned char c;
+
+	if (!skb) {
+		/* skip this block */
+		gigaset_new_rx_skb(bcs);
+		return numbytes;
+	}
+
+	while (procbytes < numbytes && skb->len < bcs->rx_bufsize) {
+		c = *src++;
+		procbytes++;
+
+		if (c == DLE_FLAG) {
+			if (inputstate & INS_DLE_char) {
+				/* quoted DLE: clear quote flag */
+				inputstate &= ~INS_DLE_char;
+			} else if (cs->dle || (inputstate & INS_DLE_command)) {
+				/* DLE escape, pass up for handling */
+				inputstate |= INS_DLE_char;
+				break;
+			}
+		}
+
+		/* regular data byte: append to current skb */
+		inputstate |= INS_have_data;
+		__skb_put_u8(skb, bitrev8(c));
+	}
+
+	/* pass data up */
+	if (inputstate & INS_have_data) {
+		gigaset_skb_rcvd(bcs, skb);
+		inputstate &= ~INS_have_data;
+		gigaset_new_rx_skb(bcs);
+	}
+
+	bcs->inputstate = inputstate;
+	return procbytes;
+}
+
+/* process DLE escapes
+ * Called whenever a DLE sequence might be encountered in the input stream.
+ * Either processes the entire DLE sequence or, if that isn't possible,
+ * notes the fact that an initial DLE has been received in the INS_DLE_char
+ * inputstate flag and resumes processing of the sequence on the next call.
+ */
+static void handle_dle(struct inbuf_t *inbuf)
+{
+	struct cardstate *cs = inbuf->cs;
+
+	if (cs->mstate == MS_LOCKED)
+		return;		/* no DLE processing in lock mode */
+
+	if (!(inbuf->inputstate & INS_DLE_char)) {
+		/* no DLE pending */
+		if (inbuf->data[inbuf->head] == DLE_FLAG &&
+		    (cs->dle || inbuf->inputstate & INS_DLE_command)) {
+			/* start of DLE sequence */
+			inbuf->head++;
+			if (inbuf->head == inbuf->tail ||
+			    inbuf->head == RBUFSIZE) {
+				/* end of buffer, save for later processing */
+				inbuf->inputstate |= INS_DLE_char;
+				return;
+			}
+		} else {
+			/* regular data byte */
+			return;
+		}
+	}
+
+	/* consume pending DLE */
+	inbuf->inputstate &= ~INS_DLE_char;
+
+	switch (inbuf->data[inbuf->head]) {
+	case 'X':	/* begin of event message */
+		if (inbuf->inputstate & INS_command)
+			dev_notice(cs->dev,
+				   "received <DLE>X in command mode\n");
+		inbuf->inputstate |= INS_command | INS_DLE_command;
+		inbuf->head++;	/* byte consumed */
+		break;
+	case '.':	/* end of event message */
+		if (!(inbuf->inputstate & INS_DLE_command))
+			dev_notice(cs->dev,
+				   "received <DLE>. without <DLE>X\n");
+		inbuf->inputstate &= ~INS_DLE_command;
+		/* return to data mode if in DLE mode */
+		if (cs->dle)
+			inbuf->inputstate &= ~INS_command;
+		inbuf->head++;	/* byte consumed */
+		break;
+	case DLE_FLAG:	/* DLE in data stream */
+		/* mark as quoted */
+		inbuf->inputstate |= INS_DLE_char;
+		if (!(cs->dle || inbuf->inputstate & INS_DLE_command))
+			dev_notice(cs->dev,
+				   "received <DLE><DLE> not in DLE mode\n");
+		break;	/* quoted byte left in buffer */
+	default:
+		dev_notice(cs->dev, "received <DLE><%02x>\n",
+			   inbuf->data[inbuf->head]);
+		/* quoted byte left in buffer */
+	}
+}
+
+/**
+ * gigaset_m10x_input() - process a block of data received from the device
+ * @inbuf:	received data and device descriptor structure.
+ *
+ * Called by hardware module {ser,usb}_gigaset with a block of received
+ * bytes. Separates the bytes received over the serial data channel into
+ * user data and command replies (locked/unlocked) according to the
+ * current state of the interface.
+ */
+void gigaset_m10x_input(struct inbuf_t *inbuf)
+{
+	struct cardstate *cs = inbuf->cs;
+	unsigned numbytes, procbytes;
+
+	gig_dbg(DEBUG_INTR, "buffer state: %u -> %u", inbuf->head, inbuf->tail);
+
+	while (inbuf->head != inbuf->tail) {
+		/* check for DLE escape */
+		handle_dle(inbuf);
+
+		/* process a contiguous block of bytes */
+		numbytes = (inbuf->head > inbuf->tail ?
+			    RBUFSIZE : inbuf->tail) - inbuf->head;
+		gig_dbg(DEBUG_INTR, "processing %u bytes", numbytes);
+		/*
+		 * numbytes may be 0 if handle_dle() ate the last byte.
+		 * This does no harm, *_loop() will just return 0 immediately.
+		 */
+
+		if (cs->mstate == MS_LOCKED)
+			procbytes = lock_loop(numbytes, inbuf);
+		else if (inbuf->inputstate & INS_command)
+			procbytes = cmd_loop(numbytes, inbuf);
+		else if (cs->bcs->proto2 == L2_HDLC)
+			procbytes = hdlc_loop(numbytes, inbuf);
+		else
+			procbytes = iraw_loop(numbytes, inbuf);
+		inbuf->head += procbytes;
+
+		/* check for buffer wraparound */
+		if (inbuf->head >= RBUFSIZE)
+			inbuf->head = 0;
+
+		gig_dbg(DEBUG_INTR, "head set to %u", inbuf->head);
+	}
+}
+EXPORT_SYMBOL_GPL(gigaset_m10x_input);
+
+
+/* == data output ========================================================== */
+
+/*
+ * Encode a data packet into an octet stuffed HDLC frame with FCS,
+ * opening and closing flags, preserving headroom data.
+ * parameters:
+ *	skb		skb containing original packet (freed upon return)
+ * Return value:
+ *	pointer to newly allocated skb containing the result frame
+ *	and the original link layer header, NULL on error
+ */
+static struct sk_buff *HDLC_Encode(struct sk_buff *skb)
+{
+	struct sk_buff *hdlc_skb;
+	__u16 fcs;
+	unsigned char c;
+	unsigned char *cp;
+	int len;
+	unsigned int stuf_cnt;
+
+	stuf_cnt = 0;
+	fcs = PPP_INITFCS;
+	cp = skb->data;
+	len = skb->len;
+	while (len--) {
+		if (muststuff(*cp))
+			stuf_cnt++;
+		fcs = crc_ccitt_byte(fcs, *cp++);
+	}
+	fcs ^= 0xffff;			/* complement */
+
+	/* size of new buffer: original size + number of stuffing bytes
+	 * + 2 bytes FCS + 2 stuffing bytes for FCS (if needed) + 2 flag bytes
+	 * + room for link layer header
+	 */
+	hdlc_skb = dev_alloc_skb(skb->len + stuf_cnt + 6 + skb->mac_len);
+	if (!hdlc_skb) {
+		dev_kfree_skb_any(skb);
+		return NULL;
+	}
+
+	/* Copy link layer header into new skb */
+	skb_reset_mac_header(hdlc_skb);
+	skb_reserve(hdlc_skb, skb->mac_len);
+	memcpy(skb_mac_header(hdlc_skb), skb_mac_header(skb), skb->mac_len);
+	hdlc_skb->mac_len = skb->mac_len;
+
+	/* Add flag sequence in front of everything.. */
+	skb_put_u8(hdlc_skb, PPP_FLAG);
+
+	/* Perform byte stuffing while copying data. */
+	while (skb->len--) {
+		if (muststuff(*skb->data)) {
+			skb_put_u8(hdlc_skb, PPP_ESCAPE);
+			skb_put_u8(hdlc_skb, (*skb->data++) ^ PPP_TRANS);
+		} else
+			skb_put_u8(hdlc_skb, *skb->data++);
+	}
+
+	/* Finally add FCS (byte stuffed) and flag sequence */
+	c = (fcs & 0x00ff);	/* least significant byte first */
+	if (muststuff(c)) {
+		skb_put_u8(hdlc_skb, PPP_ESCAPE);
+		c ^= PPP_TRANS;
+	}
+	skb_put_u8(hdlc_skb, c);
+
+	c = ((fcs >> 8) & 0x00ff);
+	if (muststuff(c)) {
+		skb_put_u8(hdlc_skb, PPP_ESCAPE);
+		c ^= PPP_TRANS;
+	}
+	skb_put_u8(hdlc_skb, c);
+
+	skb_put_u8(hdlc_skb, PPP_FLAG);
+
+	dev_kfree_skb_any(skb);
+	return hdlc_skb;
+}
+
+/*
+ * Encode a data packet into an octet stuffed raw bit inverted frame,
+ * preserving headroom data.
+ * parameters:
+ *	skb		skb containing original packet (freed upon return)
+ * Return value:
+ *	pointer to newly allocated skb containing the result frame
+ *	and the original link layer header, NULL on error
+ */
+static struct sk_buff *iraw_encode(struct sk_buff *skb)
+{
+	struct sk_buff *iraw_skb;
+	unsigned char c;
+	unsigned char *cp;
+	int len;
+
+	/* size of new buffer (worst case = every byte must be stuffed):
+	 * 2 * original size + room for link layer header
+	 */
+	iraw_skb = dev_alloc_skb(2 * skb->len + skb->mac_len);
+	if (!iraw_skb) {
+		dev_kfree_skb_any(skb);
+		return NULL;
+	}
+
+	/* copy link layer header into new skb */
+	skb_reset_mac_header(iraw_skb);
+	skb_reserve(iraw_skb, skb->mac_len);
+	memcpy(skb_mac_header(iraw_skb), skb_mac_header(skb), skb->mac_len);
+	iraw_skb->mac_len = skb->mac_len;
+
+	/* copy and stuff data */
+	cp = skb->data;
+	len = skb->len;
+	while (len--) {
+		c = bitrev8(*cp++);
+		if (c == DLE_FLAG)
+			skb_put_u8(iraw_skb, c);
+		skb_put_u8(iraw_skb, c);
+	}
+	dev_kfree_skb_any(skb);
+	return iraw_skb;
+}
+
+/**
+ * gigaset_m10x_send_skb() - queue an skb for sending
+ * @bcs:	B channel descriptor structure.
+ * @skb:	data to send.
+ *
+ * Called by LL to encode and queue an skb for sending, and start
+ * transmission if necessary.
+ * Once the payload data has been transmitted completely, gigaset_skb_sent()
+ * will be called with the skb's link layer header preserved.
+ *
+ * Return value:
+ *	number of bytes accepted for sending (skb->len) if ok,
+ *	error code < 0 (eg. -ENOMEM) on error
+ */
+int gigaset_m10x_send_skb(struct bc_state *bcs, struct sk_buff *skb)
+{
+	struct cardstate *cs = bcs->cs;
+	unsigned len = skb->len;
+	unsigned long flags;
+
+	if (bcs->proto2 == L2_HDLC)
+		skb = HDLC_Encode(skb);
+	else
+		skb = iraw_encode(skb);
+	if (!skb) {
+		dev_err(cs->dev,
+			"unable to allocate memory for encoding!\n");
+		return -ENOMEM;
+	}
+
+	skb_queue_tail(&bcs->squeue, skb);
+	spin_lock_irqsave(&cs->lock, flags);
+	if (cs->connected)
+		tasklet_schedule(&cs->write_tasklet);
+	spin_unlock_irqrestore(&cs->lock, flags);
+
+	return len;	/* ok so far */
+}
+EXPORT_SYMBOL_GPL(gigaset_m10x_send_skb);
diff --git a/drivers/staging/isdn/gigaset/bas-gigaset.c b/drivers/staging/isdn/gigaset/bas-gigaset.c
new file mode 100644
index 000000000000..149b1aca52a2
--- /dev/null
+++ b/drivers/staging/isdn/gigaset/bas-gigaset.c
@@ -0,0 +1,2675 @@
+/*
+ * USB driver for Gigaset 307x base via direct USB connection.
+ *
+ * Copyright (c) 2001 by Hansjoerg Lipp <hjlipp@web.de>,
+ *                       Tilman Schmidt <tilman@imap.cc>,
+ *                       Stefan Eilers.
+ *
+ * =====================================================================
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License as
+ *	published by the Free Software Foundation; either version 2 of
+ *	the License, or (at your option) any later version.
+ * =====================================================================
+ */
+
+#include "gigaset.h"
+#include <linux/usb.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+/* Version Information */
+#define DRIVER_AUTHOR "Tilman Schmidt <tilman@imap.cc>, Hansjoerg Lipp <hjlipp@web.de>, Stefan Eilers"
+#define DRIVER_DESC "USB Driver for Gigaset 307x"
+
+
+/* Module parameters */
+
+static int startmode = SM_ISDN;
+static int cidmode = 1;
+
+module_param(startmode, int, S_IRUGO);
+module_param(cidmode, int, S_IRUGO);
+MODULE_PARM_DESC(startmode, "start in isdn4linux mode");
+MODULE_PARM_DESC(cidmode, "Call-ID mode");
+
+#define GIGASET_MINORS     1
+#define GIGASET_MINOR      16
+#define GIGASET_MODULENAME "bas_gigaset"
+#define GIGASET_DEVNAME    "ttyGB"
+
+/* length limit according to Siemens 3070usb-protokoll.doc ch. 2.1 */
+#define IF_WRITEBUF 264
+
+/* interrupt pipe message size according to ibid. ch. 2.2 */
+#define IP_MSGSIZE 3
+
+/* Values for the Gigaset 307x */
+#define USB_GIGA_VENDOR_ID      0x0681
+#define USB_3070_PRODUCT_ID     0x0001
+#define USB_3075_PRODUCT_ID     0x0002
+#define USB_SX303_PRODUCT_ID    0x0021
+#define USB_SX353_PRODUCT_ID    0x0022
+
+/* table of devices that work with this driver */
+static const struct usb_device_id gigaset_table[] = {
+	{ USB_DEVICE(USB_GIGA_VENDOR_ID, USB_3070_PRODUCT_ID) },
+	{ USB_DEVICE(USB_GIGA_VENDOR_ID, USB_3075_PRODUCT_ID) },
+	{ USB_DEVICE(USB_GIGA_VENDOR_ID, USB_SX303_PRODUCT_ID) },
+	{ USB_DEVICE(USB_GIGA_VENDOR_ID, USB_SX353_PRODUCT_ID) },
+	{ } /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, gigaset_table);
+
+/*======================= local function prototypes ==========================*/
+
+/* function called if a new device belonging to this driver is connected */
+static int gigaset_probe(struct usb_interface *interface,
+			 const struct usb_device_id *id);
+
+/* Function will be called if the device is unplugged */
+static void gigaset_disconnect(struct usb_interface *interface);
+
+/* functions called before/after suspend */
+static int gigaset_suspend(struct usb_interface *intf, pm_message_t message);
+static int gigaset_resume(struct usb_interface *intf);
+
+/* functions called before/after device reset */
+static int gigaset_pre_reset(struct usb_interface *intf);
+static int gigaset_post_reset(struct usb_interface *intf);
+
+static int atread_submit(struct cardstate *, int);
+static void stopurbs(struct bas_bc_state *);
+static int req_submit(struct bc_state *, int, int, int);
+static int atwrite_submit(struct cardstate *, unsigned char *, int);
+static int start_cbsend(struct cardstate *);
+
+/*============================================================================*/
+
+struct bas_cardstate {
+	struct usb_device	*udev;		/* USB device pointer */
+	struct cardstate	*cs;
+	struct usb_interface	*interface;	/* interface for this device */
+	unsigned char		minor;		/* starting minor number */
+
+	struct urb		*urb_ctrl;	/* control pipe default URB */
+	struct usb_ctrlrequest	dr_ctrl;
+	struct timer_list	timer_ctrl;	/* control request timeout */
+	int			retry_ctrl;
+
+	struct timer_list	timer_atrdy;	/* AT command ready timeout */
+	struct urb		*urb_cmd_out;	/* for sending AT commands */
+	struct usb_ctrlrequest	dr_cmd_out;
+	int			retry_cmd_out;
+
+	struct urb		*urb_cmd_in;	/* for receiving AT replies */
+	struct usb_ctrlrequest	dr_cmd_in;
+	struct timer_list	timer_cmd_in;	/* receive request timeout */
+	unsigned char		*rcvbuf;	/* AT reply receive buffer */
+
+	struct urb		*urb_int_in;	/* URB for interrupt pipe */
+	unsigned char		*int_in_buf;
+	struct work_struct	int_in_wq;	/* for usb_clear_halt() */
+	struct timer_list	timer_int_in;	/* int read retry delay */
+	int			retry_int_in;
+
+	spinlock_t		lock;		/* locks all following */
+	int			basstate;	/* bitmap (BS_*) */
+	int			pending;	/* uncompleted base request */
+	wait_queue_head_t	waitqueue;
+	int			rcvbuf_size;	/* size of AT receive buffer */
+						/* 0: no receive in progress */
+	int			retry_cmd_in;	/* receive req retry count */
+};
+
+/* status of direct USB connection to 307x base (bits in basstate) */
+#define BS_ATOPEN	0x001	/* AT channel open */
+#define BS_B1OPEN	0x002	/* B channel 1 open */
+#define BS_B2OPEN	0x004	/* B channel 2 open */
+#define BS_ATREADY	0x008	/* base ready for AT command */
+#define BS_INIT		0x010	/* base has signalled INIT_OK */
+#define BS_ATTIMER	0x020	/* waiting for HD_READY_SEND_ATDATA */
+#define BS_ATRDPEND	0x040	/* urb_cmd_in in use */
+#define BS_ATWRPEND	0x080	/* urb_cmd_out in use */
+#define BS_SUSPEND	0x100	/* USB port suspended */
+#define BS_RESETTING	0x200	/* waiting for HD_RESET_INTERRUPT_PIPE_ACK */
+
+
+static struct gigaset_driver *driver;
+
+/* usb specific object needed to register this driver with the usb subsystem */
+static struct usb_driver gigaset_usb_driver = {
+	.name =         GIGASET_MODULENAME,
+	.probe =        gigaset_probe,
+	.disconnect =   gigaset_disconnect,
+	.id_table =     gigaset_table,
+	.suspend =	gigaset_suspend,
+	.resume =	gigaset_resume,
+	.reset_resume =	gigaset_post_reset,
+	.pre_reset =	gigaset_pre_reset,
+	.post_reset =	gigaset_post_reset,
+	.disable_hub_initiated_lpm = 1,
+};
+
+/* get message text for usb_submit_urb return code
+ */
+static char *get_usb_rcmsg(int rc)
+{
+	static char unkmsg[28];
+
+	switch (rc) {
+	case 0:
+		return "success";
+	case -ENOMEM:
+		return "out of memory";
+	case -ENODEV:
+		return "device not present";
+	case -ENOENT:
+		return "endpoint not present";
+	case -ENXIO:
+		return "URB type not supported";
+	case -EINVAL:
+		return "invalid argument";
+	case -EAGAIN:
+		return "start frame too early or too much scheduled";
+	case -EFBIG:
+		return "too many isoc frames requested";
+	case -EPIPE:
+		return "endpoint stalled";
+	case -EMSGSIZE:
+		return "invalid packet size";
+	case -ENOSPC:
+		return "would overcommit USB bandwidth";
+	case -ESHUTDOWN:
+		return "device shut down";
+	case -EPERM:
+		return "reject flag set";
+	case -EHOSTUNREACH:
+		return "device suspended";
+	default:
+		snprintf(unkmsg, sizeof(unkmsg), "unknown error %d", rc);
+		return unkmsg;
+	}
+}
+
+/* get message text for USB status code
+ */
+static char *get_usb_statmsg(int status)
+{
+	static char unkmsg[28];
+
+	switch (status) {
+	case 0:
+		return "success";
+	case -ENOENT:
+		return "unlinked (sync)";
+	case -EINPROGRESS:
+		return "URB still pending";
+	case -EPROTO:
+		return "bitstuff error, timeout, or unknown USB error";
+	case -EILSEQ:
+		return "CRC mismatch, timeout, or unknown USB error";
+	case -ETIME:
+		return "USB response timeout";
+	case -EPIPE:
+		return "endpoint stalled";
+	case -ECOMM:
+		return "IN buffer overrun";
+	case -ENOSR:
+		return "OUT buffer underrun";
+	case -EOVERFLOW:
+		return "endpoint babble";
+	case -EREMOTEIO:
+		return "short packet";
+	case -ENODEV:
+		return "device removed";
+	case -EXDEV:
+		return "partial isoc transfer";
+	case -EINVAL:
+		return "ISO madness";
+	case -ECONNRESET:
+		return "unlinked (async)";
+	case -ESHUTDOWN:
+		return "device shut down";
+	default:
+		snprintf(unkmsg, sizeof(unkmsg), "unknown status %d", status);
+		return unkmsg;
+	}
+}
+
+/* usb_pipetype_str
+ * retrieve string representation of USB pipe type
+ */
+static inline char *usb_pipetype_str(int pipe)
+{
+	if (usb_pipeisoc(pipe))
+		return "Isoc";
+	if (usb_pipeint(pipe))
+		return "Int";
+	if (usb_pipecontrol(pipe))
+		return "Ctrl";
+	if (usb_pipebulk(pipe))
+		return "Bulk";
+	return "?";
+}
+
+/* dump_urb
+ * write content of URB to syslog for debugging
+ */
+static inline void dump_urb(enum debuglevel level, const char *tag,
+			    struct urb *urb)