1 files changed, 613 insertions, 0 deletions

diff --git a/drivers/staging/isdn/gigaset/interface.c b/drivers/staging/isdn/gigaset/interface.c
new file mode 100644
index 000000000000..17fa615a8c68
--- /dev/null
+++ b/drivers/staging/isdn/gigaset/interface.c
@@ -0,0 +1,613 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * interface to user space for the gigaset driver
+ *
+ * Copyright (c) 2004 by Hansjoerg Lipp <hjlipp@web.de>
+ *
+ * =====================================================================
+ * =====================================================================
+ */
+
+#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);
+}