X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fisdn%2Fgigaset%2Fi4l.c;fp=kernel%2Fdrivers%2Fisdn%2Fgigaset%2Fi4l.c;h=2d75329007f158e31975a1d745e147a75ef8e7e6;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git

diff --git a/kernel/drivers/isdn/gigaset/i4l.c b/kernel/drivers/isdn/gigaset/i4l.c
new file mode 100644
index 000000000..2d7532900
--- /dev/null
+++ b/kernel/drivers/isdn/gigaset/i4l.c
@@ -0,0 +1,695 @@
+/*
+ * Stuff used by all variants of the driver
+ *
+ * Copyright (c) 2001 by Stefan Eilers,
+ *                       Hansjoerg Lipp <hjlipp@web.de>,
+ *                       Tilman Schmidt <tilman@imap.cc>.
+ *
+ * =====================================================================
+ *	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/isdnif.h>
+#include <linux/export.h>
+
+#define SBUFSIZE	4096	/* sk_buff payload size */
+#define TRANSBUFSIZE	768	/* bytes per skb for transparent receive */
+#define HW_HDR_LEN	2	/* Header size used to store ack info */
+#define MAX_BUF_SIZE	(SBUFSIZE - HW_HDR_LEN)	/* max data packet from LL */
+
+/* == Handling of I4L IO =====================================================*/
+
+/* writebuf_from_LL
+ * called by LL to transmit data on an open channel
+ * inserts the buffer data into the send queue and starts the transmission
+ * Note that this operation must not sleep!
+ * When the buffer is processed completely, gigaset_skb_sent() should be called.
+ * parameters:
+ *	driverID	driver ID as assigned by LL
+ *	channel		channel number
+ *	ack		if != 0 LL wants to be notified on completion via
+ *			statcallb(ISDN_STAT_BSENT)
+ *	skb		skb containing data to send
+ * return value:
+ *	number of accepted bytes
+ *	0 if temporarily unable to accept data (out of buffer space)
+ *	<0 on error (eg. -EINVAL)
+ */
+static int writebuf_from_LL(int driverID, int channel, int ack,
+			    struct sk_buff *skb)
+{
+	struct cardstate *cs = gigaset_get_cs_by_id(driverID);
+	struct bc_state *bcs;
+	unsigned char *ack_header;
+	unsigned len;
+
+	if (!cs) {
+		pr_err("%s: invalid driver ID (%d)\n", __func__, driverID);
+		return -ENODEV;
+	}
+	if (channel < 0 || channel >= cs->channels) {
+		dev_err(cs->dev, "%s: invalid channel ID (%d)\n",
+			__func__, channel);
+		return -ENODEV;
+	}
+	bcs = &cs->bcs[channel];
+
+	/* can only handle linear sk_buffs */
+	if (skb_linearize(skb) < 0) {
+		dev_err(cs->dev, "%s: skb_linearize failed\n", __func__);
+		return -ENOMEM;
+	}
+	len = skb->len;
+
+	gig_dbg(DEBUG_LLDATA,
+		"Receiving data from LL (id: %d, ch: %d, ack: %d, sz: %d)",
+		driverID, channel, ack, len);
+
+	if (!len) {
+		if (ack)
+			dev_notice(cs->dev, "%s: not ACKing empty packet\n",
+				   __func__);
+		return 0;
+	}
+	if (len > MAX_BUF_SIZE) {
+		dev_err(cs->dev, "%s: packet too large (%d bytes)\n",
+			__func__, len);
+		return -EINVAL;
+	}
+
+	/* set up acknowledgement header */
+	if (skb_headroom(skb) < HW_HDR_LEN) {
+		/* should never happen */
+		dev_err(cs->dev, "%s: insufficient skb headroom\n", __func__);
+		return -ENOMEM;
+	}
+	skb_set_mac_header(skb, -HW_HDR_LEN);
+	skb->mac_len = HW_HDR_LEN;
+	ack_header = skb_mac_header(skb);
+	if (ack) {
+		ack_header[0] = len & 0xff;
+		ack_header[1] = len >> 8;
+	} else {
+		ack_header[0] = ack_header[1] = 0;
+	}
+	gig_dbg(DEBUG_MCMD, "skb: len=%u, ack=%d: %02x %02x",
+		len, ack, ack_header[0], ack_header[1]);
+
+	/* pass to device-specific module */
+	return cs->ops->send_skb(bcs, skb);
+}
+
+/**
+ * gigaset_skb_sent() - acknowledge sending an skb
+ * @bcs:	B channel descriptor structure.
+ * @skb:	sent data.
+ *
+ * Called by hardware module {bas,ser,usb}_gigaset when the data in a
+ * skb has been successfully sent, for signalling completion to the LL.
+ */
+void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *skb)
+{
+	isdn_if *iif = bcs->cs->iif;
+	unsigned char *ack_header = skb_mac_header(skb);
+	unsigned len;
+	isdn_ctrl response;
+
+	++bcs->trans_up;
+
+	if (skb->len)
+		dev_warn(bcs->cs->dev, "%s: skb->len==%d\n",
+			 __func__, skb->len);
+
+	len = ack_header[0] + ((unsigned) ack_header[1] << 8);
+	if (len) {
+		gig_dbg(DEBUG_MCMD, "ACKing to LL (id: %d, ch: %d, sz: %u)",
+			bcs->cs->myid, bcs->channel, len);
+
+		response.driver = bcs->cs->myid;
+		response.command = ISDN_STAT_BSENT;
+		response.arg = bcs->channel;
+		response.parm.length = len;
+		iif->statcallb(&response);
+	}
+}
+EXPORT_SYMBOL_GPL(gigaset_skb_sent);
+
+/**
+ * gigaset_skb_rcvd() - pass received skb to LL
+ * @bcs:	B channel descriptor structure.
+ * @skb:	received data.
+ *
+ * Called by hardware module {bas,ser,usb}_gigaset when user data has
+ * been successfully received, for passing to the LL.
+ * Warning: skb must not be accessed anymore!
+ */
+void gigaset_skb_rcvd(struct bc_state *bcs, struct sk_buff *skb)
+{
+	isdn_if *iif = bcs->cs->iif;
+
+	iif->rcvcallb_skb(bcs->cs->myid, bcs->channel, skb);
+	bcs->trans_down++;
+}
+EXPORT_SYMBOL_GPL(gigaset_skb_rcvd);
+
+/**
+ * gigaset_isdn_rcv_err() - signal receive error
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by hardware module {bas,ser,usb}_gigaset when a receive error
+ * has occurred, for signalling to the LL.
+ */
+void gigaset_isdn_rcv_err(struct bc_state *bcs)
+{
+	isdn_if *iif = bcs->cs->iif;
+	isdn_ctrl response;
+
+	/* if currently ignoring packets, just count down */
+	if (bcs->ignore) {
+		bcs->ignore--;
+		return;
+	}
+
+	/* update statistics */
+	bcs->corrupted++;
+
+	/* error -> LL */
+	gig_dbg(DEBUG_CMD, "sending L1ERR");
+	response.driver = bcs->cs->myid;
+	response.command = ISDN_STAT_L1ERR;
+	response.arg = bcs->channel;
+	response.parm.errcode = ISDN_STAT_L1ERR_RECV;
+	iif->statcallb(&response);
+}
+EXPORT_SYMBOL_GPL(gigaset_isdn_rcv_err);
+
+/* This function will be called by LL to send commands
+ * NOTE: LL ignores the returned value, for commands other than ISDN_CMD_IOCTL,
+ * so don't put too much effort into it.
+ */
+static int command_from_LL(isdn_ctrl *cntrl)
+{
+	struct cardstate *cs;
+	struct bc_state *bcs;
+	int retval = 0;
+	char **commands;
+	int ch;
+	int i;
+	size_t l;
+
+	gig_dbg(DEBUG_CMD, "driver: %d, command: %d, arg: 0x%lx",
+		cntrl->driver, cntrl->command, cntrl->arg);
+
+	cs = gigaset_get_cs_by_id(cntrl->driver);
+	if (cs == NULL) {
+		pr_err("%s: invalid driver ID (%d)\n", __func__, cntrl->driver);
+		return -ENODEV;
+	}
+	ch = cntrl->arg & 0xff;
+
+	switch (cntrl->command) {
+	case ISDN_CMD_IOCTL:
+		dev_warn(cs->dev, "ISDN_CMD_IOCTL not supported\n");
+		return -EINVAL;
+
+	case ISDN_CMD_DIAL:
+		gig_dbg(DEBUG_CMD,
+			"ISDN_CMD_DIAL (phone: %s, msn: %s, si1: %d, si2: %d)",
+			cntrl->parm.setup.phone, cntrl->parm.setup.eazmsn,
+			cntrl->parm.setup.si1, cntrl->parm.setup.si2);
+
+		if (ch >= cs->channels) {
+			dev_err(cs->dev,
+				"ISDN_CMD_DIAL: invalid channel (%d)\n", ch);
+			return -EINVAL;
+		}
+		bcs = cs->bcs + ch;
+		if (gigaset_get_channel(bcs) < 0) {
+			dev_err(cs->dev, "ISDN_CMD_DIAL: channel not free\n");
+			return -EBUSY;
+		}
+		switch (bcs->proto2) {
+		case L2_HDLC:
+			bcs->rx_bufsize = SBUFSIZE;
+			break;
+		default:			/* assume transparent */
+			bcs->rx_bufsize = TRANSBUFSIZE;
+		}
+		dev_kfree_skb(bcs->rx_skb);
+		gigaset_new_rx_skb(bcs);
+
+		commands = kzalloc(AT_NUM * (sizeof *commands), GFP_ATOMIC);
+		if (!commands) {
+			gigaset_free_channel(bcs);
+			dev_err(cs->dev, "ISDN_CMD_DIAL: out of memory\n");
+			return -ENOMEM;
+		}
+
+		l = 3 + strlen(cntrl->parm.setup.phone);
+		commands[AT_DIAL] = kmalloc(l, GFP_ATOMIC);
+		if (!commands[AT_DIAL])
+			goto oom;
+		if (cntrl->parm.setup.phone[0] == '*' &&
+		    cntrl->parm.setup.phone[1] == '*') {
+			/* internal call: translate ** prefix to CTP value */
+			commands[AT_TYPE] = kstrdup("^SCTP=0\r", GFP_ATOMIC);
+			if (!commands[AT_TYPE])
+				goto oom;
+			snprintf(commands[AT_DIAL], l,
+				 "D%s\r", cntrl->parm.setup.phone + 2);
+		} else {
+			commands[AT_TYPE] = kstrdup("^SCTP=1\r", GFP_ATOMIC);
+			if (!commands[AT_TYPE])
+				goto oom;
+			snprintf(commands[AT_DIAL], l,
+				 "D%s\r", cntrl->parm.setup.phone);
+		}
+
+		l = strlen(cntrl->parm.setup.eazmsn);
+		if (l) {
+			l += 8;
+			commands[AT_MSN] = kmalloc(l, GFP_ATOMIC);
+			if (!commands[AT_MSN])
+				goto oom;
+			snprintf(commands[AT_MSN], l, "^SMSN=%s\r",
+				 cntrl->parm.setup.eazmsn);
+		}
+
+		switch (cntrl->parm.setup.si1) {
+		case 1:		/* audio */
+			/* BC = 9090A3: 3.1 kHz audio, A-law */
+			commands[AT_BC] = kstrdup("^SBC=9090A3\r", GFP_ATOMIC);
+			if (!commands[AT_BC])
+				goto oom;
+			break;
+		case 7:		/* data */
+		default:	/* hope the app knows what it is doing */
+			/* BC = 8890: unrestricted digital information */
+			commands[AT_BC] = kstrdup("^SBC=8890\r", GFP_ATOMIC);
+			if (!commands[AT_BC])
+				goto oom;
+		}
+		/* ToDo: other si1 values, inspect si2, set HLC/LLC */
+
+		commands[AT_PROTO] = kmalloc(9, GFP_ATOMIC);
+		if (!commands[AT_PROTO])
+			goto oom;
+		snprintf(commands[AT_PROTO], 9, "^SBPR=%u\r", bcs->proto2);
+
+		commands[AT_ISO] = kmalloc(9, GFP_ATOMIC);
+		if (!commands[AT_ISO])
+			goto oom;
+		snprintf(commands[AT_ISO], 9, "^SISO=%u\r",
+			 (unsigned) bcs->channel + 1);
+
+		if (!gigaset_add_event(cs, &bcs->at_state, EV_DIAL, commands,
+				       bcs->at_state.seq_index, NULL)) {
+			for (i = 0; i < AT_NUM; ++i)
+				kfree(commands[i]);
+			kfree(commands);
+			gigaset_free_channel(bcs);
+			return -ENOMEM;
+		}
+		gigaset_schedule_event(cs);
+		break;
+	case ISDN_CMD_ACCEPTD:
+		gig_dbg(DEBUG_CMD, "ISDN_CMD_ACCEPTD");
+		if (ch >= cs->channels) {
+			dev_err(cs->dev,
+				"ISDN_CMD_ACCEPTD: invalid channel (%d)\n", ch);
+			return -EINVAL;
+		}
+		bcs = cs->bcs + ch;
+		switch (bcs->proto2) {
+		case L2_HDLC:
+			bcs->rx_bufsize = SBUFSIZE;
+			break;
+		default:			/* assume transparent */
+			bcs->rx_bufsize = TRANSBUFSIZE;
+		}
+		dev_kfree_skb(bcs->rx_skb);
+		gigaset_new_rx_skb(bcs);
+		if (!gigaset_add_event(cs, &bcs->at_state,
+				       EV_ACCEPT, NULL, 0, NULL))
+			return -ENOMEM;
+		gigaset_schedule_event(cs);
+
+		break;
+	case ISDN_CMD_HANGUP:
+		gig_dbg(DEBUG_CMD, "ISDN_CMD_HANGUP");
+		if (ch >= cs->channels) {
+			dev_err(cs->dev,
+				"ISDN_CMD_HANGUP: invalid channel (%d)\n", ch);
+			return -EINVAL;
+		}
+		bcs = cs->bcs + ch;
+		if (!gigaset_add_event(cs, &bcs->at_state,
+				       EV_HUP, NULL, 0, NULL))
+			return -ENOMEM;
+		gigaset_schedule_event(cs);
+
+		break;
+	case ISDN_CMD_CLREAZ: /* Do not signal incoming signals */
+		dev_info(cs->dev, "ignoring ISDN_CMD_CLREAZ\n");
+		break;
+	case ISDN_CMD_SETEAZ: /* Signal incoming calls for given MSN */
+		dev_info(cs->dev, "ignoring ISDN_CMD_SETEAZ (%s)\n",
+			 cntrl->parm.num);
+		break;
+	case ISDN_CMD_SETL2: /* Set L2 to given protocol */
+		if (ch >= cs->channels) {
+			dev_err(cs->dev,
+				"ISDN_CMD_SETL2: invalid channel (%d)\n", ch);
+			return -EINVAL;
+		}
+		bcs = cs->bcs + ch;
+		if (bcs->chstate & CHS_D_UP) {
+			dev_err(cs->dev,
+				"ISDN_CMD_SETL2: channel active (%d)\n", ch);
+			return -EINVAL;
+		}
+		switch (cntrl->arg >> 8) {
+		case ISDN_PROTO_L2_HDLC:
+			gig_dbg(DEBUG_CMD, "ISDN_CMD_SETL2: setting L2_HDLC");
+			bcs->proto2 = L2_HDLC;
+			break;
+		case ISDN_PROTO_L2_TRANS:
+			gig_dbg(DEBUG_CMD, "ISDN_CMD_SETL2: setting L2_VOICE");
+			bcs->proto2 = L2_VOICE;
+			break;
+		default:
+			dev_err(cs->dev,
+				"ISDN_CMD_SETL2: unsupported protocol (%lu)\n",
+				cntrl->arg >> 8);
+			return -EINVAL;
+		}
+		break;
+	case ISDN_CMD_SETL3: /* Set L3 to given protocol */
+		gig_dbg(DEBUG_CMD, "ISDN_CMD_SETL3");
+		if (ch >= cs->channels) {
+			dev_err(cs->dev,
+				"ISDN_CMD_SETL3: invalid channel (%d)\n", ch);
+			return -EINVAL;
+		}
+
+		if (cntrl->arg >> 8 != ISDN_PROTO_L3_TRANS) {
+			dev_err(cs->dev,
+				"ISDN_CMD_SETL3: unsupported protocol (%lu)\n",
+				cntrl->arg >> 8);
+			return -EINVAL;
+		}
+
+		break;
+
+	default:
+		gig_dbg(DEBUG_CMD, "unknown command %d from LL",
+			cntrl->command);
+		return -EINVAL;
+	}
+
+	return retval;
+
+oom:
+	dev_err(bcs->cs->dev, "out of memory\n");
+	for (i = 0; i < AT_NUM; ++i)
+		kfree(commands[i]);
+	kfree(commands);
+	gigaset_free_channel(bcs);
+	return -ENOMEM;
+}
+
+static void gigaset_i4l_cmd(struct cardstate *cs, int cmd)
+{
+	isdn_if *iif = cs->iif;
+	isdn_ctrl command;
+
+	command.driver = cs->myid;
+	command.command = cmd;
+	command.arg = 0;
+	iif->statcallb(&command);
+}
+
+static void gigaset_i4l_channel_cmd(struct bc_state *bcs, int cmd)
+{
+	isdn_if *iif = bcs->cs->iif;
+	isdn_ctrl command;
+
+	command.driver = bcs->cs->myid;
+	command.command = cmd;
+	command.arg = bcs->channel;
+	iif->statcallb(&command);
+}
+
+/**
+ * gigaset_isdn_icall() - signal incoming call
+ * @at_state:	connection state structure.
+ *
+ * Called by main module to notify the LL that an incoming call has been
+ * received. @at_state contains the parameters of the call.
+ *
+ * Return value: call disposition (ICALL_*)
+ */
+int gigaset_isdn_icall(struct at_state_t *at_state)
+{
+	struct cardstate *cs = at_state->cs;
+	struct bc_state *bcs = at_state->bcs;
+	isdn_if *iif = cs->iif;
+	isdn_ctrl response;
+	int retval;
+
+	/* fill ICALL structure */
+	response.parm.setup.si1 = 0;	/* default: unknown */
+	response.parm.setup.si2 = 0;
+	response.parm.setup.screen = 0;
+	response.parm.setup.plan = 0;
+	if (!at_state->str_var[STR_ZBC]) {
+		/* no BC (internal call): assume speech, A-law */
+		response.parm.setup.si1 = 1;
+	} else if (!strcmp(at_state->str_var[STR_ZBC], "8890")) {
+		/* unrestricted digital information */
+		response.parm.setup.si1 = 7;
+	} else if (!strcmp(at_state->str_var[STR_ZBC], "8090A3")) {
+		/* speech, A-law */
+		response.parm.setup.si1 = 1;
+	} else if (!strcmp(at_state->str_var[STR_ZBC], "9090A3")) {
+		/* 3,1 kHz audio, A-law */
+		response.parm.setup.si1 = 1;
+		response.parm.setup.si2 = 2;
+	} else {
+		dev_warn(cs->dev, "RING ignored - unsupported BC %s\n",
+			 at_state->str_var[STR_ZBC]);
+		return ICALL_IGNORE;
+	}
+	if (at_state->str_var[STR_NMBR]) {
+		strlcpy(response.parm.setup.phone, at_state->str_var[STR_NMBR],
+			sizeof response.parm.setup.phone);
+	} else
+		response.parm.setup.phone[0] = 0;
+	if (at_state->str_var[STR_ZCPN]) {
+		strlcpy(response.parm.setup.eazmsn, at_state->str_var[STR_ZCPN],
+			sizeof response.parm.setup.eazmsn);
+	} else
+		response.parm.setup.eazmsn[0] = 0;
+
+	if (!bcs) {
+		dev_notice(cs->dev, "no channel for incoming call\n");
+		response.command = ISDN_STAT_ICALLW;
+		response.arg = 0;
+	} else {
+		gig_dbg(DEBUG_CMD, "Sending ICALL");
+		response.command = ISDN_STAT_ICALL;
+		response.arg = bcs->channel;
+	}
+	response.driver = cs->myid;
+	retval = iif->statcallb(&response);
+	gig_dbg(DEBUG_CMD, "Response: %d", retval);
+	switch (retval) {
+	case 0:	/* no takers */
+		return ICALL_IGNORE;
+	case 1:	/* alerting */
+		bcs->chstate |= CHS_NOTIFY_LL;
+		return ICALL_ACCEPT;
+	case 2:	/* reject */
+		return ICALL_REJECT;
+	case 3:	/* incomplete */
+		dev_warn(cs->dev,
+			 "LL requested unsupported feature: Incomplete Number\n");
+		return ICALL_IGNORE;
+	case 4:	/* proceeding */
+		/* Gigaset will send ALERTING anyway.
+		 * There doesn't seem to be a way to avoid this.
+		 */
+		return ICALL_ACCEPT;
+	case 5:	/* deflect */
+		dev_warn(cs->dev,
+			 "LL requested unsupported feature: Call Deflection\n");
+		return ICALL_IGNORE;
+	default:
+		dev_err(cs->dev, "LL error %d on ICALL\n", retval);
+		return ICALL_IGNORE;
+	}
+}
+
+/**
+ * gigaset_isdn_connD() - signal D channel connect
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by main module to notify the LL that the D channel connection has
+ * been established.
+ */
+void gigaset_isdn_connD(struct bc_state *bcs)
+{
+	gig_dbg(DEBUG_CMD, "sending DCONN");
+	gigaset_i4l_channel_cmd(bcs, ISDN_STAT_DCONN);
+}
+
+/**
+ * gigaset_isdn_hupD() - signal D channel hangup
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by main module to notify the LL that the D channel connection has
+ * been shut down.
+ */
+void gigaset_isdn_hupD(struct bc_state *bcs)
+{
+	gig_dbg(DEBUG_CMD, "sending DHUP");
+	gigaset_i4l_channel_cmd(bcs, ISDN_STAT_DHUP);
+}
+
+/**
+ * gigaset_isdn_connB() - signal B channel connect
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by main module to notify the LL that the B channel connection has
+ * been established.
+ */
+void gigaset_isdn_connB(struct bc_state *bcs)
+{
+	gig_dbg(DEBUG_CMD, "sending BCONN");
+	gigaset_i4l_channel_cmd(bcs, ISDN_STAT_BCONN);
+}
+
+/**
+ * gigaset_isdn_hupB() - signal B channel hangup
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by main module to notify the LL that the B channel connection has
+ * been shut down.
+ */
+void gigaset_isdn_hupB(struct bc_state *bcs)
+{
+	gig_dbg(DEBUG_CMD, "sending BHUP");
+	gigaset_i4l_channel_cmd(bcs, ISDN_STAT_BHUP);
+}
+
+/**
+ * gigaset_isdn_start() - signal device availability
+ * @cs:		device descriptor structure.
+ *
+ * Called by main module to notify the LL that the device is available for
+ * use.
+ */
+void gigaset_isdn_start(struct cardstate *cs)
+{
+	gig_dbg(DEBUG_CMD, "sending RUN");
+	gigaset_i4l_cmd(cs, ISDN_STAT_RUN);
+}
+
+/**
+ * gigaset_isdn_stop() - signal device unavailability
+ * @cs:		device descriptor structure.
+ *
+ * Called by main module to notify the LL that the device is no longer
+ * available for use.
+ */
+void gigaset_isdn_stop(struct cardstate *cs)
+{
+	gig_dbg(DEBUG_CMD, "sending STOP");
+	gigaset_i4l_cmd(cs, ISDN_STAT_STOP);
+}
+
+/**
+ * gigaset_isdn_regdev() - register to LL
+ * @cs:		device descriptor structure.
+ * @isdnid:	device name.
+ *
+ * Return value: 0 on success, error code < 0 on failure
+ */
+int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
+{
+	isdn_if *iif;
+
+	iif = kmalloc(sizeof *iif, GFP_KERNEL);
+	if (!iif) {
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+
+	if (snprintf(iif->id, sizeof iif->id, "%s_%u", isdnid, cs->minor_index)
+	    >= sizeof iif->id) {
+		pr_err("ID too long: %s\n", isdnid);
+		kfree(iif);
+		return -EINVAL;
+	}
+
+	iif->owner = THIS_MODULE;
+	iif->channels = cs->channels;
+	iif->maxbufsize = MAX_BUF_SIZE;
+	iif->features = ISDN_FEATURE_L2_TRANS |
+		ISDN_FEATURE_L2_HDLC |
+		ISDN_FEATURE_L2_X75I |
+		ISDN_FEATURE_L3_TRANS |
+		ISDN_FEATURE_P_EURO;
+	iif->hl_hdrlen = HW_HDR_LEN;		/* Area for storing ack */
+	iif->command = command_from_LL;
+	iif->writebuf_skb = writebuf_from_LL;
+	iif->writecmd = NULL;			/* Don't support isdnctrl */
+	iif->readstat = NULL;			/* Don't support isdnctrl */
+	iif->rcvcallb_skb = NULL;		/* Will be set by LL */
+	iif->statcallb = NULL;			/* Will be set by LL */
+
+	if (!register_isdn(iif)) {
+		pr_err("register_isdn failed\n");
+		kfree(iif);
+		return -EINVAL;
+	}
+
+	cs->iif = iif;
+	cs->myid = iif->channels;		/* Set my device id */
+	cs->hw_hdr_len = HW_HDR_LEN;
+	return 0;
+}
+
+/**
+ * gigaset_isdn_unregdev() - unregister device from LL
+ * @cs:		device descriptor structure.
+ */
+void gigaset_isdn_unregdev(struct cardstate *cs)
+{
+	gig_dbg(DEBUG_CMD, "sending UNLOAD");
+	gigaset_i4l_cmd(cs, ISDN_STAT_UNLOAD);
+	kfree(cs->iif);
+	cs->iif = NULL;
+}
+
+/**
+ * gigaset_isdn_regdrv() - register driver to LL
+ */
+void gigaset_isdn_regdrv(void)
+{
+	pr_info("ISDN4Linux interface\n");
+	/* nothing to do */
+}
+
+/**
+ * gigaset_isdn_unregdrv() - unregister driver from LL
+ */
+void gigaset_isdn_unregdrv(void)
+{
+	/* nothing to do */
+}