a97a6f1077
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
136 lines
3.5 KiB
C
136 lines
3.5 KiB
C
/*********************************************************************
|
|
*
|
|
* sir_dongle.c: manager for serial dongle protocol drivers
|
|
*
|
|
* Copyright (c) 2002 Martin Diehl
|
|
*
|
|
* 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 <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kmod.h>
|
|
#include <linux/mutex.h>
|
|
|
|
#include <net/irda/irda.h>
|
|
|
|
#include "sir-dev.h"
|
|
|
|
/**************************************************************************
|
|
*
|
|
* dongle registration and attachment
|
|
*
|
|
*/
|
|
|
|
static LIST_HEAD(dongle_list); /* list of registered dongle drivers */
|
|
static DEFINE_MUTEX(dongle_list_lock); /* protects the list */
|
|
|
|
int irda_register_dongle(struct dongle_driver *new)
|
|
{
|
|
struct list_head *entry;
|
|
struct dongle_driver *drv;
|
|
|
|
IRDA_DEBUG(0, "%s : registering dongle \"%s\" (%d).\n",
|
|
__func__, new->driver_name, new->type);
|
|
|
|
mutex_lock(&dongle_list_lock);
|
|
list_for_each(entry, &dongle_list) {
|
|
drv = list_entry(entry, struct dongle_driver, dongle_list);
|
|
if (new->type == drv->type) {
|
|
mutex_unlock(&dongle_list_lock);
|
|
return -EEXIST;
|
|
}
|
|
}
|
|
list_add(&new->dongle_list, &dongle_list);
|
|
mutex_unlock(&dongle_list_lock);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(irda_register_dongle);
|
|
|
|
int irda_unregister_dongle(struct dongle_driver *drv)
|
|
{
|
|
mutex_lock(&dongle_list_lock);
|
|
list_del(&drv->dongle_list);
|
|
mutex_unlock(&dongle_list_lock);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(irda_unregister_dongle);
|
|
|
|
int sirdev_get_dongle(struct sir_dev *dev, IRDA_DONGLE type)
|
|
{
|
|
struct list_head *entry;
|
|
const struct dongle_driver *drv = NULL;
|
|
int err = -EINVAL;
|
|
|
|
#ifdef CONFIG_KMOD
|
|
request_module("irda-dongle-%d", type);
|
|
#endif
|
|
|
|
if (dev->dongle_drv != NULL)
|
|
return -EBUSY;
|
|
|
|
/* serialize access to the list of registered dongles */
|
|
mutex_lock(&dongle_list_lock);
|
|
|
|
list_for_each(entry, &dongle_list) {
|
|
drv = list_entry(entry, struct dongle_driver, dongle_list);
|
|
if (drv->type == type)
|
|
break;
|
|
else
|
|
drv = NULL;
|
|
}
|
|
|
|
if (!drv) {
|
|
err = -ENODEV;
|
|
goto out_unlock; /* no such dongle */
|
|
}
|
|
|
|
/* handling of SMP races with dongle module removal - three cases:
|
|
* 1) dongle driver was already unregistered - then we haven't found the
|
|
* requested dongle above and are already out here
|
|
* 2) the module is already marked deleted but the driver is still
|
|
* registered - then the try_module_get() below will fail
|
|
* 3) the try_module_get() below succeeds before the module is marked
|
|
* deleted - then sys_delete_module() fails and prevents the removal
|
|
* because the module is in use.
|
|
*/
|
|
|
|
if (!try_module_get(drv->owner)) {
|
|
err = -ESTALE;
|
|
goto out_unlock; /* rmmod already pending */
|
|
}
|
|
dev->dongle_drv = drv;
|
|
|
|
if (!drv->open || (err=drv->open(dev))!=0)
|
|
goto out_reject; /* failed to open driver */
|
|
|
|
mutex_unlock(&dongle_list_lock);
|
|
return 0;
|
|
|
|
out_reject:
|
|
dev->dongle_drv = NULL;
|
|
module_put(drv->owner);
|
|
out_unlock:
|
|
mutex_unlock(&dongle_list_lock);
|
|
return err;
|
|
}
|
|
|
|
int sirdev_put_dongle(struct sir_dev *dev)
|
|
{
|
|
const struct dongle_driver *drv = dev->dongle_drv;
|
|
|
|
if (drv) {
|
|
if (drv->close)
|
|
drv->close(dev); /* close this dongle instance */
|
|
|
|
dev->dongle_drv = NULL; /* unlink the dongle driver */
|
|
module_put(drv->owner);/* decrement driver's module refcount */
|
|
}
|
|
|
|
return 0;
|
|
}
|