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>

1 files changed, 0 insertions, 609 deletions

diff --git a/drivers/isdn/gigaset/asyncdata.c b/drivers/isdn/gigaset/asyncdata.c
deleted file mode 100644
index c0cbee06bc21..000000000000
--- a/drivers/isdn/gigaset/asyncdata.c
+++ /dev/null
@@ -1,609 +0,0 @@
-/*
- * 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);