linux/drivers/isdn/gigaset/interface.c
Alan Cox adc8d746ca tty: move the termios object into the tty
This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16 13:00:41 -07:00

633 lines
15 KiB
C

/*
* 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 ***/
/* stolen from usbserial and some other tty drivers */
static int if_open(struct tty_struct *tty, struct file *filp);
static void if_close(struct tty_struct *tty, struct file *filp);
static int if_ioctl(struct tty_struct *tty,
unsigned int cmd, unsigned long arg);
static int if_write_room(struct tty_struct *tty);
static int if_chars_in_buffer(struct tty_struct *tty);
static void if_throttle(struct tty_struct *tty);
static void if_unthrottle(struct tty_struct *tty);
static void if_set_termios(struct tty_struct *tty, struct ktermios *old);
static int if_tiocmget(struct tty_struct *tty);
static int if_tiocmset(struct tty_struct *tty,
unsigned int set, unsigned int clear);
static int if_write(struct tty_struct *tty,
const unsigned char *buf, int count);
static const struct tty_operations if_ops = {
.open = if_open,
.close = if_close,
.ioctl = if_ioctl,
.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,
};
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);
tty->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, (const unsigned char *) arg);
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;
}
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 = -ENODEV;
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);
}
/* wakeup tasklet for the write operation */
static void if_wake(unsigned long data)
{
struct cardstate *cs = (struct cardstate *)data;
struct tty_struct *tty = tty_port_tty_get(&cs->port);
if (tty) {
tty_wakeup(tty);
tty_kref_put(tty);
}
}
/*** 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_register_device(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)
{
struct tty_struct *tty = tty_port_tty_get(&cs->port);
if (tty == NULL) {
gig_dbg(DEBUG_IF, "receive on closed device");
return;
}
tty_insert_flip_string(tty, buffer, len);
tty_flip_buffer_push(tty);
tty_kref_put(tty);
}
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);
}