[net-next-2.6.git] / net / wireless / chan.c

/*
 * This file contains helper code to handle channel
 * settings and keeping track of what is possible at
 * any point in time.
 *
 * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
 */

#include <net/cfg80211.h>
#include "core.h"

struct ieee80211_channel *
rdev_fixed_channel(struct cfg80211_registered_device *rdev,
		   struct wireless_dev *for_wdev)
{
	struct wireless_dev *wdev;
	struct ieee80211_channel *result = NULL;

	WARN_ON(!mutex_is_locked(&rdev->devlist_mtx));

	list_for_each_entry(wdev, &rdev->netdev_list, list) {
		if (wdev == for_wdev)
			continue;

		/*
		 * Lock manually to tell lockdep about allowed
		 * nesting here if for_wdev->mtx is held already.
		 * This is ok as it's all under the rdev devlist
		 * mutex and as such can only be done once at any
		 * given time.
		 */
		mutex_lock_nested(&wdev->mtx, SINGLE_DEPTH_NESTING);
		if (wdev->current_bss)
			result = wdev->current_bss->pub.channel;
		wdev_unlock(wdev);

		if (result)
			break;
	}

	return result;
}

struct ieee80211_channel *
rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
		  int freq, enum nl80211_channel_type channel_type)
{
	struct ieee80211_channel *chan;
	struct ieee80211_sta_ht_cap *ht_cap;

	chan = ieee80211_get_channel(&rdev->wiphy, freq);

	/* Primary channel not allowed */
	if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
		return NULL;

	if (channel_type == NL80211_CHAN_HT40MINUS &&
	    chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
		return NULL;
	else if (channel_type == NL80211_CHAN_HT40PLUS &&
		 chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
		return NULL;

	ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;

	if (channel_type != NL80211_CHAN_NO_HT) {
		if (!ht_cap->ht_supported)
			return NULL;

		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
			return NULL;
	}

	return chan;
}

int rdev_set_freq(struct cfg80211_registered_device *rdev,
		  struct wireless_dev *for_wdev,
		  int freq, enum nl80211_channel_type channel_type)
{
	struct ieee80211_channel *chan;
	int result;

	if (rdev_fixed_channel(rdev, for_wdev))
		return -EBUSY;

	if (!rdev->ops->set_channel)
		return -EOPNOTSUPP;

	chan = rdev_freq_to_chan(rdev, freq, channel_type);
	if (!chan)
		return -EINVAL;

	result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
	if (result)
		return result;

	rdev->channel = chan;

	return 0;
}
Commit	Line	Data
59bbb6f7 JB	1	/*
	2	* This file contains helper code to handle channel
	3	* settings and keeping track of what is possible at
	4	* any point in time.
	5	*
	6	* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
	7	*/
	8
	9	#include <net/cfg80211.h>
	10	#include "core.h"
	11
	12	struct ieee80211_channel *
	13	rdev_fixed_channel(struct cfg80211_registered_device *rdev,
	14	struct wireless_dev *for_wdev)
	15	{
	16	struct wireless_dev *wdev;
	17	struct ieee80211_channel *result = NULL;
	18
	19	WARN_ON(!mutex_is_locked(&rdev->devlist_mtx));
	20
	21	list_for_each_entry(wdev, &rdev->netdev_list, list) {
	22	if (wdev == for_wdev)
	23	continue;
	24
	25	/*
	26	* Lock manually to tell lockdep about allowed
	27	* nesting here if for_wdev->mtx is held already.
	28	* This is ok as it's all under the rdev devlist
	29	* mutex and as such can only be done once at any
	30	* given time.
	31	*/
	32	mutex_lock_nested(&wdev->mtx, SINGLE_DEPTH_NESTING);
	33	if (wdev->current_bss)
	34	result = wdev->current_bss->pub.channel;
	35	wdev_unlock(wdev);
	36
	37	if (result)
	38	break;
	39	}
	40
	41	return result;
	42	}
	43
9588bbd5 JM	44	struct ieee80211_channel *
9588bbd5 JM	45	rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
59bbb6f7 JB	46	int freq, enum nl80211_channel_type channel_type)
	47	{
	48	struct ieee80211_channel *chan;
	49	struct ieee80211_sta_ht_cap *ht_cap;
59bbb6f7 JB	50
	51	chan = ieee80211_get_channel(&rdev->wiphy, freq);
	52
	53	/* Primary channel not allowed */
	54	if (!chan \|\| chan->flags & IEEE80211_CHAN_DISABLED)
9588bbd5	55	return NULL;
59bbb6f7 JB	56
	57	if (channel_type == NL80211_CHAN_HT40MINUS &&
	58	chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
9588bbd5	59	return NULL;
59bbb6f7 JB	60	else if (channel_type == NL80211_CHAN_HT40PLUS &&
59bbb6f7 JB	61	chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
9588bbd5	62	return NULL;
59bbb6f7 JB	63
	64	ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
	65
	66	if (channel_type != NL80211_CHAN_NO_HT) {
	67	if (!ht_cap->ht_supported)
9588bbd5	68	return NULL;
59bbb6f7 JB	69
	70	if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) \|\|
	71	ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
9588bbd5	72	return NULL;
59bbb6f7 JB	73	}
59bbb6f7 JB	74
9588bbd5 JM	75	return chan;
	76	}
	77
	78	int rdev_set_freq(struct cfg80211_registered_device *rdev,
	79	struct wireless_dev *for_wdev,
	80	int freq, enum nl80211_channel_type channel_type)
	81	{
	82	struct ieee80211_channel *chan;
	83	int result;
	84
	85	if (rdev_fixed_channel(rdev, for_wdev))
	86	return -EBUSY;
	87
	88	if (!rdev->ops->set_channel)
	89	return -EOPNOTSUPP;
	90
	91	chan = rdev_freq_to_chan(rdev, freq, channel_type);
	92	if (!chan)
	93	return -EINVAL;
	94
59bbb6f7 JB	95	result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
	96	if (result)
	97	return result;
	98
	99	rdev->channel = chan;
	100
	101	return 0;
	102	}