linux/drivers/uwb/pal.c

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/*
* UWB PAL support.
*
* Copyright (C) 2008 Cambridge Silicon Radio Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/kernel.h>
#include <linux/debugfs.h>
#include <linux/uwb.h>
#include <linux/export.h>
#include "uwb-internal.h"
/**
* uwb_pal_init - initialize a UWB PAL
* @pal: the PAL to initialize
*/
void uwb_pal_init(struct uwb_pal *pal)
{
INIT_LIST_HEAD(&pal->node);
}
EXPORT_SYMBOL_GPL(uwb_pal_init);
/**
* uwb_pal_register - register a UWB PAL
* @pal: the PAL
*
* The PAL must be initialized with uwb_pal_init().
*/
int uwb_pal_register(struct uwb_pal *pal)
{
struct uwb_rc *rc = pal->rc;
int ret;
if (pal->device) {
/* create a link to the uwb_rc in the PAL device's directory. */
ret = sysfs_create_link(&pal->device->kobj,
&rc->uwb_dev.dev.kobj, "uwb_rc");
if (ret < 0)
return ret;
/* create a link to the PAL in the UWB device's directory. */
ret = sysfs_create_link(&rc->uwb_dev.dev.kobj,
&pal->device->kobj, pal->name);
if (ret < 0) {
sysfs_remove_link(&pal->device->kobj, "uwb_rc");
return ret;
}
}
pal->debugfs_dir = uwb_dbg_create_pal_dir(pal);
mutex_lock(&rc->uwb_dev.mutex);
list_add(&pal->node, &rc->pals);
mutex_unlock(&rc->uwb_dev.mutex);
return 0;
}
EXPORT_SYMBOL_GPL(uwb_pal_register);
static int find_rc(struct device *dev, const void *data)
{
const struct uwb_rc *target_rc = data;
struct uwb_rc *rc = dev_get_drvdata(dev);
if (rc == NULL) {
WARN_ON(1);
return 0;
}
if (rc == target_rc) {
if (rc->ready == 0)
return 0;
else
return 1;
}
return 0;
}
/**
* Given a radio controller descriptor see if it is registered.
*
* @returns false if the rc does not exist or is quiescing; true otherwise.
*/
static bool uwb_rc_class_device_exists(struct uwb_rc *target_rc)
{
struct device *dev;
dev = class_find_device(&uwb_rc_class, NULL, target_rc, find_rc);
put_device(dev);
return (dev != NULL);
}
/**
* uwb_pal_unregister - unregister a UWB PAL
* @pal: the PAL
*/
void uwb_pal_unregister(struct uwb_pal *pal)
{
struct uwb_rc *rc = pal->rc;
uwb_radio_stop(pal);
mutex_lock(&rc->uwb_dev.mutex);
list_del(&pal->node);
mutex_unlock(&rc->uwb_dev.mutex);
debugfs_remove(pal->debugfs_dir);
if (pal->device) {
/* remove link to the PAL in the UWB device's directory. */
if (uwb_rc_class_device_exists(rc))
sysfs_remove_link(&rc->uwb_dev.dev.kobj, pal->name);
/* remove link to uwb_rc in the PAL device's directory. */
sysfs_remove_link(&pal->device->kobj, "uwb_rc");
}
}
EXPORT_SYMBOL_GPL(uwb_pal_unregister);
/**
* uwb_rc_pal_init - initialize the PAL related parts of a radio controller
* @rc: the radio controller
*/
void uwb_rc_pal_init(struct uwb_rc *rc)
{
INIT_LIST_HEAD(&rc->pals);
}