linux/drivers/uwb/radio.c
Thomas Gleixner caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00

197 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* UWB radio (channel) management.
*
* Copyright (C) 2008 Cambridge Silicon Radio Ltd.
*/
#include <linux/kernel.h>
#include <linux/uwb.h>
#include <linux/export.h>
#include "uwb-internal.h"
static int uwb_radio_select_channel(struct uwb_rc *rc)
{
/*
* Default to channel 9 (BG1, TFC1) unless the user has
* selected a specific channel or there are no active PALs.
*/
if (rc->active_pals == 0)
return -1;
if (rc->beaconing_forced)
return rc->beaconing_forced;
return 9;
}
/*
* Notify all active PALs that the channel has changed.
*/
static void uwb_radio_channel_changed(struct uwb_rc *rc, int channel)
{
struct uwb_pal *pal;
list_for_each_entry(pal, &rc->pals, node) {
if (pal->channel && channel != pal->channel) {
pal->channel = channel;
if (pal->channel_changed)
pal->channel_changed(pal, pal->channel);
}
}
}
/*
* Change to a new channel and notify any active PALs of the new
* channel.
*
* When stopping the radio, PALs need to be notified first so they can
* terminate any active reservations.
*/
static int uwb_radio_change_channel(struct uwb_rc *rc, int channel)
{
int ret = 0;
struct device *dev = &rc->uwb_dev.dev;
dev_dbg(dev, "%s: channel = %d, rc->beaconing = %d\n", __func__,
channel, rc->beaconing);
if (channel == -1)
uwb_radio_channel_changed(rc, channel);
if (channel != rc->beaconing) {
if (rc->beaconing != -1 && channel != -1) {
/*
* FIXME: should signal the channel change
* with a Channel Change IE.
*/
ret = uwb_radio_change_channel(rc, -1);
if (ret < 0)
return ret;
}
ret = uwb_rc_beacon(rc, channel, 0);
}
if (channel != -1)
uwb_radio_channel_changed(rc, rc->beaconing);
return ret;
}
/**
* uwb_radio_start - request that the radio be started
* @pal: the PAL making the request.
*
* If the radio is not already active, a suitable channel is selected
* and beacons are started.
*/
int uwb_radio_start(struct uwb_pal *pal)
{
struct uwb_rc *rc = pal->rc;
int ret = 0;
mutex_lock(&rc->uwb_dev.mutex);
if (!pal->channel) {
pal->channel = -1;
rc->active_pals++;
ret = uwb_radio_change_channel(rc, uwb_radio_select_channel(rc));
}
mutex_unlock(&rc->uwb_dev.mutex);
return ret;
}
EXPORT_SYMBOL_GPL(uwb_radio_start);
/**
* uwb_radio_stop - request that the radio be stopped.
* @pal: the PAL making the request.
*
* Stops the radio if no other PAL is making use of it.
*/
void uwb_radio_stop(struct uwb_pal *pal)
{
struct uwb_rc *rc = pal->rc;
mutex_lock(&rc->uwb_dev.mutex);
if (pal->channel) {
rc->active_pals--;
uwb_radio_change_channel(rc, uwb_radio_select_channel(rc));
pal->channel = 0;
}
mutex_unlock(&rc->uwb_dev.mutex);
}
EXPORT_SYMBOL_GPL(uwb_radio_stop);
/*
* uwb_radio_force_channel - force a specific channel to be used
* @rc: the radio controller.
* @channel: the channel to use; -1 to force the radio to stop; 0 to
* use the default channel selection algorithm.
*/
int uwb_radio_force_channel(struct uwb_rc *rc, int channel)
{
int ret = 0;
mutex_lock(&rc->uwb_dev.mutex);
rc->beaconing_forced = channel;
ret = uwb_radio_change_channel(rc, uwb_radio_select_channel(rc));
mutex_unlock(&rc->uwb_dev.mutex);
return ret;
}
/*
* uwb_radio_setup - setup the radio manager
* @rc: the radio controller.
*
* The radio controller is reset to ensure it's in a known state
* before it's used.
*/
int uwb_radio_setup(struct uwb_rc *rc)
{
return uwb_rc_reset(rc);
}
/*
* uwb_radio_reset_state - reset any radio manager state
* @rc: the radio controller.
*
* All internal radio manager state is reset to values corresponding
* to a reset radio controller.
*/
void uwb_radio_reset_state(struct uwb_rc *rc)
{
struct uwb_pal *pal;
mutex_lock(&rc->uwb_dev.mutex);
list_for_each_entry(pal, &rc->pals, node) {
if (pal->channel) {
pal->channel = -1;
if (pal->channel_changed)
pal->channel_changed(pal, -1);
}
}
rc->beaconing = -1;
rc->scanning = -1;
mutex_unlock(&rc->uwb_dev.mutex);
}
/*
* uwb_radio_shutdown - shutdown the radio manager
* @rc: the radio controller.
*
* The radio controller is reset.
*/
void uwb_radio_shutdown(struct uwb_rc *rc)
{
uwb_radio_reset_state(rc);
uwb_rc_reset(rc);
}