Merge tag 'isdn-removal' of https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground

Arnd Bergmann says:

====================
isdn: deprecate non-mISDN drivers

When isdn4linux came up in the context of another patch series, I
remembered that we had discussed removing it a while ago.

It turns out that the suggestion from Karsten Keil wa to remove I4L
in 2018 after the last public ISDN networks are shut down. This has
happened now (with a very small number of exceptions), so I guess it's
time to try again.

We currently have three ISDN stacks in the kernel: the original
isdn4linux (with the hisax driver), the newer CAPI (with four drivers),
and finally the mISDN stack (supporting roughly the same hardware as
hisax).

As far as I can tell, anyone using ISDN with mainline kernel drivers in
the past few years uses mISDN, and this is typically used for voice-only
PBX installations that don't require a public network.

The older stacks support additional features for data networks, but those
typically make no sense any more if there is no network to connect to.

My proposal for this time is to kill off isdn4linux entirely, as it seems
to have been unusable for quite a while. This code has been abandoned
for many years and it does cause problems for treewide maintenance as
it tends to do everything that we try to stop doing.
Birger Harzenetter mentioned that is is still using i4l in order to
make use of the 'divert' feature that is not part of mISDN, but has
otherwise moved on to mISDN for normal operation, like apparently
everyone else.

CAPI in turn is not quite as obsolete, but two of the drivers (avm
and hysdn) don't seem to be used at all, while another one (gigaset)
will stop being maintained as Paul Bolle is no longer able to
test it after the network gets shut down in September.
All three are now moved into drivers/staging to let others speak
up in case there are remaining users.
This leaves Bluetooth CMTP as the only remaining user of CAPI, but
Marcel Holtmann wishes to keep maintaining it.

For the discussion on version 1, see [2]
Unfortunately, Karsten Keil as the maintainer has not participated in
the discussion.

      Arnd

[1] https://patchwork.kernel.org/patch/8484861/#17900371
[2] https://listserv.isdn4linux.de/pipermail/isdn4linux/2019-April/thread.html
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 616 deletions

diff --git a/drivers/isdn/gigaset/interface.c b/drivers/isdn/gigaset/interface.c
deleted file mode 100644
index d9a578ac32cd..000000000000
--- a/drivers/isdn/gigaset/interface.c
+++ /dev/null
@@ -1,616 +0,0 @@
-/*
- * interface to user space for the gigaset driver
- *
- * Copyright (c) 2004 by Hansjoerg Lipp <hjlipp@web.de>
- *
- * =====================================================================
- *    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/gigaset_dev.h>
-#include <linux/tty_flip.h>
-#include <linux/module.h>
-
-/*** our ioctls ***/
-
-static int if_lock(struct cardstate *cs, int *arg)
-{
-	int cmd = *arg;
-
-	gig_dbg(DEBUG_IF, "%u: if_lock (%d)", cs->minor_index, cmd);
-
-	if (cmd > 1)
-		return -EINVAL;
-
-	if (cmd < 0) {
-		*arg = cs->mstate == MS_LOCKED;
-		return 0;
-	}
-
-	if (!cmd && cs->mstate == MS_LOCKED && cs->connected) {
-		cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR | TIOCM_RTS);
-		cs->ops->baud_rate(cs, B115200);
-		cs->ops->set_line_ctrl(cs, CS8);
-		cs->control_state = TIOCM_DTR | TIOCM_RTS;
-	}
-
-	cs->waiting = 1;
-	if (!gigaset_add_event(cs, &cs->at_state, EV_IF_LOCK,
-			       NULL, cmd, NULL)) {
-		cs->waiting = 0;
-		return -ENOMEM;
-	}
-	gigaset_schedule_event(cs);
-
-	wait_event(cs->waitqueue, !cs->waiting);
-
-	if (cs->cmd_result >= 0) {
-		*arg = cs->cmd_result;
-		return 0;
-	}
-
-	return cs->cmd_result;
-}
-
-static int if_version(struct cardstate *cs, unsigned arg[4])
-{
-	static const unsigned version[4] = GIG_VERSION;
-	static const unsigned compat[4] = GIG_COMPAT;
-	unsigned cmd = arg[0];
-
-	gig_dbg(DEBUG_IF, "%u: if_version (%d)", cs->minor_index, cmd);
-
-	switch (cmd) {
-	case GIGVER_DRIVER:
-		memcpy(arg, version, sizeof version);
-		return 0;
-	case GIGVER_COMPAT:
-		memcpy(arg, compat, sizeof compat);
-		return 0;
-	case GIGVER_FWBASE:
-		cs->waiting = 1;
-		if (!gigaset_add_event(cs, &cs->at_state, EV_IF_VER,
-				       NULL, 0, arg)) {
-			cs->waiting = 0;
-			return -ENOMEM;
-		}
-		gigaset_schedule_event(cs);
-
-		wait_event(cs->waitqueue, !cs->waiting);
-
-		if (cs->cmd_result >= 0)
-			return 0;
-
-		return cs->cmd_result;
-	default:
-		return -EINVAL;
-	}
-}
-
-static int if_config(struct cardstate *cs, int *arg)
-{
-	gig_dbg(DEBUG_IF, "%u: if_config (%d)", cs->minor_index, *arg);
-
-	if (*arg != 1)
-		return -EINVAL;
-
-	if (cs->mstate != MS_LOCKED)
-		return -EBUSY;
-
-	if (!cs->connected) {
-		pr_err("%s: not connected\n", __func__);
-		return -ENODEV;
-	}
-
-	*arg = 0;
-	return gigaset_enterconfigmode(cs);
-}
-
-/*** the terminal driver ***/
-
-static int if_open(struct tty_struct *tty, struct file *filp)
-{
-	struct cardstate *cs;
-
-	gig_dbg(DEBUG_IF, "%d+%d: %s()",
-		tty->driver->minor_start, tty->index, __func__);
-
-	cs = gigaset_get_cs_by_tty(tty);
-	if (!cs || !try_module_get(cs->driver->owner))
-		return -ENODEV;
-
-	if (mutex_lock_interruptible(&cs->mutex)) {
-		module_put(cs->driver->owner);
-		return -ERESTARTSYS;
-	}
-	tty->driver_data = cs;
-
-	++cs->port.count;
-
-	if (cs->port.count == 1) {
-		tty_port_tty_set(&cs->port, tty);
-		cs->port.low_latency = 1;
-	}
-
-	mutex_unlock(&cs->mutex);
-	return 0;
-}
-
-static void if_close(struct tty_struct *tty, struct file *filp)
-{
-	struct cardstate *cs = tty->driver_data;
-
-	if (!cs) { /* happens if we didn't find cs in open */
-		gig_dbg(DEBUG_IF, "%s: no cardstate", __func__);
-		return;
-	}
-
-	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
-
-	mutex_lock(&cs->mutex);
-
-	if (!cs->connected)
-		gig_dbg(DEBUG_IF, "not connected");	/* nothing to do */
-	else if (!cs->port.count)
-		dev_warn(cs->dev, "%s: device not opened\n", __func__);
-	else if (!--cs->port.count)
-		tty_port_tty_set(&cs->port, NULL);
-
-	mutex_unlock(&cs->mutex);
-
-	module_put(cs->driver->owner);
-}
-
-static int if_ioctl(struct tty_struct *tty,
-		    unsigned int cmd, unsigned long arg)
-{
-	struct cardstate *cs = tty->driver_data;
-	int retval = -ENODEV;
-	int int_arg;
-	unsigned char buf[6];
-	unsigned version[4];
-
-	gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
-
-	if (mutex_lock_interruptible(&cs->mutex))
-		return -ERESTARTSYS;
-
-	if (!cs->connected) {
-		gig_dbg(DEBUG_IF, "not connected");
-		retval = -ENODEV;
-	} else {
-		retval = 0;
-		switch (cmd) {
-		case GIGASET_REDIR:
-			retval = get_user(int_arg, (int __user *) arg);
-			if (retval >= 0)
-				retval = if_lock(cs, &int_arg);
-			if (retval >= 0)
-				retval = put_user(int_arg, (int __user *) arg);
-			break;
-		case GIGASET_CONFIG:
-			retval = get_user(int_arg, (int __user *) arg);
-			if (retval >= 0)
-				retval = if_config(cs, &int_arg);
-			if (retval >= 0)
-				retval = put_user(int_arg, (int __user *) arg);
-			break;
-		case GIGASET_BRKCHARS:
-			retval = copy_from_user(&buf,
-						(const unsigned char __user *) arg, 6)
-				? -EFAULT : 0;
-			if (retval >= 0) {
-				gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
-						   6, buf);
-				retval = cs->ops->brkchars(cs, buf);
-			}
-			break;
-		case GIGASET_VERSION:
-			retval = copy_from_user(version,
-						(unsigned __user *) arg, sizeof version)
-				? -EFAULT : 0;
-			if (retval >= 0)
-				retval = if_version(cs, version);
-			if (retval >= 0)
-				retval = copy_to_user((unsigned __user *) arg,
-						      version, sizeof version)
-					? -EFAULT : 0;
-			break;
-		default:
-			gig_dbg(DEBUG_IF, "%s: arg not supported - 0x%04x",
-				__func__, cmd);
-			retval = -ENOIOCTLCMD;
-		}
-	}
-
-	mutex_unlock(&cs->mutex);
-
-	return retval;
-}
-
-#ifdef CONFIG_COMPAT
-static long if_compat_ioctl(struct tty_struct *tty,
-		    unsigned int cmd, unsigned long arg)
-{
-	return if_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
-}
-#endif
-
-static int if_tiocmget(struct tty_struct *tty)
-{
-	struct cardstate *cs = tty->driver_data;
-	int retval;
-
-	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
-
-	if (mutex_lock_interruptible(&cs->mutex))
-		return -ERESTARTSYS;
-
-	retval = cs->control_state & (TIOCM_RTS | TIOCM_DTR);
-
-	mutex_unlock(&cs->mutex);
-
-	return retval;
-}
-
-static int if_tiocmset(struct tty_struct *tty,
-		       unsigned int set, unsigned int clear)
-{
-	struct cardstate *cs = tty->driver_data;
-	int retval;
-	unsigned mc;
-
-	gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
-		cs->minor_index, __func__, set, clear);
-
-	if (mutex_lock_interruptible(&cs->mutex))
-		return -ERESTARTSYS;
-
-	if (!cs->connected) {
-		gig_dbg(DEBUG_IF, "not connected");
-		retval = -ENODEV;
-	} else {
-		mc = (cs->control_state | set) & ~clear & (TIOCM_RTS | TIOCM_DTR);
-		retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
-		cs->control_state = mc;
-	}
-
-	mutex_unlock(&cs->mutex);
-
-	return retval;
-}
-
-static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
-{
-	struct cardstate *cs = tty->driver_data;
-	struct cmdbuf_t *cb;
-	int retval;
-
-	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
-
-	if (mutex_lock_interruptible(&cs->mutex))
-		return -ERESTARTSYS;
-
-	if (!cs->connected) {
-		gig_dbg(DEBUG_IF, "not connected");
-		retval = -ENODEV;
-		goto done;
-	}
-	if (cs->mstate != MS_LOCKED) {
-		dev_warn(cs->dev, "can't write to unlocked device\n");
-		retval = -EBUSY;
-		goto done;
-	}
-	if (count <= 0) {
-		/* nothing to do */
-		retval = 0;
-		goto done;
-	}
-
-	cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
-	if (!cb) {
-		dev_err(cs->dev, "%s: out of memory\n", __func__);
-		retval = -ENOMEM;
-		goto done;
-	}
-
-	memcpy(cb->buf, buf, count);
-	cb->len = count;
-	cb->offset = 0;
-	cb->next = NULL;
-	cb->wake_tasklet = &cs->if_wake_tasklet;
-	retval = cs->ops->write_cmd(cs, cb);
-done:
-	mutex_unlock(&cs->mutex);
-	return retval;
-}
-
-static int if_write_room(struct tty_struct *tty)
-{
-	struct cardstate *cs = tty->driver_data;
-	int retval;
-
-	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
-
-	if (mutex_lock_interruptible(&cs->mutex))
-		return -ERESTARTSYS;
-
-	if (!cs->connected) {
-		gig_dbg(DEBUG_IF, "not connected");
-		retval = -ENODEV;
-	} else if (cs->mstate != MS_LOCKED) {
-		dev_warn(cs->dev, "can't write to unlocked device\n");
-		retval = -EBUSY;
-	} else
-		retval = cs->ops->write_room(cs);
-
-	mutex_unlock(&cs->mutex);
-
-	return retval;
-}
-
-static int if_chars_in_buffer(struct tty_struct *tty)
-{
-	struct cardstate *cs = tty->driver_data;
-	int retval = 0;
-
-	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
-
-	mutex_lock(&cs->mutex);
-
-	if (!cs->connected)
-		gig_dbg(DEBUG_IF, "not connected");
-	else if (cs->mstate != MS_LOCKED)
-		dev_warn(cs->dev, "can't write to unlocked device\n");
-	else
-		retval = cs->ops->chars_in_buffer(cs);
-
-	mutex_unlock(&cs->mutex);
-
-	return retval;
-}
-
-static void if_throttle(struct tty_struct *tty)
-{
-	struct cardstate *cs = tty->driver_data;
-
-	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
-
-	mutex_lock(&cs->mutex);
-
-	if (!cs->connected)
-		gig_dbg(DEBUG_IF, "not connected");	/* nothing to do */
-	else
-		gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
-
-	mutex_unlock(&cs->mutex);
-}
-
-static void if_unthrottle(struct tty_struct *tty)
-{
-	struct cardstate *cs = tty->driver_data;
-
-	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
-
-	mutex_lock(&cs->mutex);
-
-	if (!cs->connected)
-		gig_dbg(DEBUG_IF, "not connected");	/* nothing to do */
-	else
-		gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
-
-	mutex_unlock(&cs->mutex);
-}
-
-static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
-{
-	struct cardstate *cs = tty->driver_data;
-	unsigned int iflag;
-	unsigned int cflag;
-	unsigned int old_cflag;
-	unsigned int control_state, new_state;
-
-	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
-
-	mutex_lock(&cs->mutex);
-
-	if (!cs->connected) {
-		gig_dbg(DEBUG_IF, "not connected");
-		goto out;
-	}
-
-	iflag = tty->termios.c_iflag;
-	cflag = tty->termios.c_cflag;
-	old_cflag = old ? old->c_cflag : cflag;
-	gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
-		cs->minor_index, iflag, cflag, old_cflag);
-
-	/* get a local copy of the current port settings */
-	control_state = cs->control_state;
-
-	/*
-	 * Update baud rate.
-	 * Do not attempt to cache old rates and skip settings,
-	 * disconnects screw such tricks up completely.
-	 * Premature optimization is the root of all evil.
-	 */
-
-	/* reassert DTR and (maybe) RTS on transition from B0 */
-	if ((old_cflag & CBAUD) == B0) {
-		new_state = control_state | TIOCM_DTR;
-		/* don't set RTS if using hardware flow control */
-		if (!(old_cflag & CRTSCTS))
-			new_state |= TIOCM_RTS;
-		gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
-			cs->minor_index,
-			(new_state & TIOCM_RTS) ? " only" : "/RTS");
-		cs->ops->set_modem_ctrl(cs, control_state, new_state);
-		control_state = new_state;
-	}
-
-	cs->ops->baud_rate(cs, cflag & CBAUD);
-
-	if ((cflag & CBAUD) == B0) {
-		/* Drop RTS and DTR */
-		gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
-		new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
-		cs->ops->set_modem_ctrl(cs, control_state, new_state);
-		control_state = new_state;
-	}
-
-	/*
-	 * Update line control register (LCR)
-	 */
-
-	cs->ops->set_line_ctrl(cs, cflag);
-
-	/* save off the modified port settings */
-	cs->control_state = control_state;
-
-out:
-	mutex_unlock(&cs->mutex);
-}
-
-static const struct tty_operations if_ops = {
-	.open =			if_open,
-	.close =		if_close,
-	.ioctl =		if_ioctl,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl =		if_compat_ioctl,
-#endif
-	.write =		if_write,
-	.write_room =		if_write_room,
-	.chars_in_buffer =	if_chars_in_buffer,
-	.set_termios =		if_set_termios,
-	.throttle =		if_throttle,
-	.unthrottle =		if_unthrottle,
-	.tiocmget =		if_tiocmget,
-	.tiocmset =		if_tiocmset,
-};
-
-
-/* wakeup tasklet for the write operation */
-static void if_wake(unsigned long data)
-{
-	struct cardstate *cs = (struct cardstate *)data;
-
-	tty_port_tty_wakeup(&cs->port);
-}
-
-/*** interface to common ***/
-
-void gigaset_if_init(struct cardstate *cs)
-{
-	struct gigaset_driver *drv;
-
-	drv = cs->driver;
-	if (!drv->have_tty)
-		return;
-
-	tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
-
-	mutex_lock(&cs->mutex);
-	cs->tty_dev = tty_port_register_device(&cs->port, drv->tty,
-			cs->minor_index, NULL);
-
-	if (!IS_ERR(cs->tty_dev))
-		dev_set_drvdata(cs->tty_dev, cs);
-	else {
-		pr_warning("could not register device to the tty subsystem\n");
-		cs->tty_dev = NULL;
-	}
-	mutex_unlock(&cs->mutex);
-}
-
-void gigaset_if_free(struct cardstate *cs)
-{
-	struct gigaset_driver *drv;
-
-	drv = cs->driver;
-	if (!drv->have_tty)
-		return;
-
-	tasklet_disable(&cs->if_wake_tasklet);
-	tasklet_kill(&cs->if_wake_tasklet);
-	cs->tty_dev = NULL;
-	tty_unregister_device(drv->tty, cs->minor_index);
-}
-
-/**
- * gigaset_if_receive() - pass a received block of data to the tty device
- * @cs:		device descriptor structure.
- * @buffer:	received data.
- * @len:	number of bytes received.
- *
- * Called by asyncdata/isocdata if a block of data received from the
- * device must be sent to userspace through the ttyG* device.
- */
-void gigaset_if_receive(struct cardstate *cs,
-			unsigned char *buffer, size_t len)
-{
-	tty_insert_flip_string(&cs->port, buffer, len);
-	tty_flip_buffer_push(&cs->port);
-}
-EXPORT_SYMBOL_GPL(gigaset_if_receive);
-
-/* gigaset_if_initdriver
- * Initialize tty interface.
- * parameters:
- *	drv		Driver
- *	procname	Name of the driver (e.g. for /proc/tty/drivers)
- *	devname		Name of the device files (prefix without minor number)
- */
-void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
-			   const char *devname)
-{
-	int ret;
-	struct tty_driver *tty;
-
-	drv->have_tty = 0;
-
-	drv->tty = tty = alloc_tty_driver(drv->minors);
-	if (tty == NULL)
-		goto enomem;
-
-	tty->type =		TTY_DRIVER_TYPE_SERIAL;
-	tty->subtype =		SERIAL_TYPE_NORMAL;
-	tty->flags =		TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
-
-	tty->driver_name =	procname;
-	tty->name =		devname;
-	tty->minor_start =	drv->minor;
-
-	tty->init_termios          = tty_std_termios;
-	tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
-	tty_set_operations(tty, &if_ops);
-
-	ret = tty_register_driver(tty);
-	if (ret < 0) {
-		pr_err("error %d registering tty driver\n", ret);
-		goto error;
-	}
-	gig_dbg(DEBUG_IF, "tty driver initialized");
-	drv->have_tty = 1;
-	return;
-
-enomem:
-	pr_err("out of memory\n");
-error:
-	if (drv->tty)
-		put_tty_driver(drv->tty);
-}
-
-void gigaset_if_freedriver(struct gigaset_driver *drv)
-{
-	if (!drv->have_tty)
-		return;
-
-	drv->have_tty = 0;
-	tty_unregister_driver(drv->tty);
-	put_tty_driver(drv->tty);
-}