xref: /openbmc/linux/drivers/net/wireless/st/cw1200/scan.c (revision 5d331b7f)
1 /*
2  * Scan implementation for ST-Ericsson CW1200 mac80211 drivers
3  *
4  * Copyright (c) 2010, ST-Ericsson
5  * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/sched.h>
13 #include "cw1200.h"
14 #include "scan.h"
15 #include "sta.h"
16 #include "pm.h"
17 
18 static void cw1200_scan_restart_delayed(struct cw1200_common *priv);
19 
20 static int cw1200_scan_start(struct cw1200_common *priv, struct wsm_scan *scan)
21 {
22 	int ret, i;
23 	int tmo = 2000;
24 
25 	switch (priv->join_status) {
26 	case CW1200_JOIN_STATUS_PRE_STA:
27 	case CW1200_JOIN_STATUS_JOINING:
28 		return -EBUSY;
29 	default:
30 		break;
31 	}
32 
33 	wiphy_dbg(priv->hw->wiphy, "[SCAN] hw req, type %d, %d channels, flags: 0x%x.\n",
34 		  scan->type, scan->num_channels, scan->flags);
35 
36 	for (i = 0; i < scan->num_channels; ++i)
37 		tmo += scan->ch[i].max_chan_time + 10;
38 
39 	cancel_delayed_work_sync(&priv->clear_recent_scan_work);
40 	atomic_set(&priv->scan.in_progress, 1);
41 	atomic_set(&priv->recent_scan, 1);
42 	cw1200_pm_stay_awake(&priv->pm_state, msecs_to_jiffies(tmo));
43 	queue_delayed_work(priv->workqueue, &priv->scan.timeout,
44 			   msecs_to_jiffies(tmo));
45 	ret = wsm_scan(priv, scan);
46 	if (ret) {
47 		atomic_set(&priv->scan.in_progress, 0);
48 		cancel_delayed_work_sync(&priv->scan.timeout);
49 		cw1200_scan_restart_delayed(priv);
50 	}
51 	return ret;
52 }
53 
54 int cw1200_hw_scan(struct ieee80211_hw *hw,
55 		   struct ieee80211_vif *vif,
56 		   struct ieee80211_scan_request *hw_req)
57 {
58 	struct cw1200_common *priv = hw->priv;
59 	struct cfg80211_scan_request *req = &hw_req->req;
60 	struct wsm_template_frame frame = {
61 		.frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
62 	};
63 	int i, ret;
64 
65 	if (!priv->vif)
66 		return -EINVAL;
67 
68 	/* Scan when P2P_GO corrupt firmware MiniAP mode */
69 	if (priv->join_status == CW1200_JOIN_STATUS_AP)
70 		return -EOPNOTSUPP;
71 
72 	if (req->n_ssids == 1 && !req->ssids[0].ssid_len)
73 		req->n_ssids = 0;
74 
75 	wiphy_dbg(hw->wiphy, "[SCAN] Scan request for %d SSIDs.\n",
76 		  req->n_ssids);
77 
78 	if (req->n_ssids > WSM_SCAN_MAX_NUM_OF_SSIDS)
79 		return -EINVAL;
80 
81 	frame.skb = ieee80211_probereq_get(hw, priv->vif->addr, NULL, 0,
82 		req->ie_len);
83 	if (!frame.skb)
84 		return -ENOMEM;
85 
86 	if (req->ie_len)
87 		skb_put_data(frame.skb, req->ie, req->ie_len);
88 
89 	/* will be unlocked in cw1200_scan_work() */
90 	down(&priv->scan.lock);
91 	mutex_lock(&priv->conf_mutex);
92 
93 	ret = wsm_set_template_frame(priv, &frame);
94 	if (!ret) {
95 		/* Host want to be the probe responder. */
96 		ret = wsm_set_probe_responder(priv, true);
97 	}
98 	if (ret) {
99 		mutex_unlock(&priv->conf_mutex);
100 		up(&priv->scan.lock);
101 		dev_kfree_skb(frame.skb);
102 		return ret;
103 	}
104 
105 	wsm_lock_tx(priv);
106 
107 	BUG_ON(priv->scan.req);
108 	priv->scan.req = req;
109 	priv->scan.n_ssids = 0;
110 	priv->scan.status = 0;
111 	priv->scan.begin = &req->channels[0];
112 	priv->scan.curr = priv->scan.begin;
113 	priv->scan.end = &req->channels[req->n_channels];
114 	priv->scan.output_power = priv->output_power;
115 
116 	for (i = 0; i < req->n_ssids; ++i) {
117 		struct wsm_ssid *dst = &priv->scan.ssids[priv->scan.n_ssids];
118 		memcpy(&dst->ssid[0], req->ssids[i].ssid, sizeof(dst->ssid));
119 		dst->length = req->ssids[i].ssid_len;
120 		++priv->scan.n_ssids;
121 	}
122 
123 	mutex_unlock(&priv->conf_mutex);
124 
125 	if (frame.skb)
126 		dev_kfree_skb(frame.skb);
127 	queue_work(priv->workqueue, &priv->scan.work);
128 	return 0;
129 }
130 
131 void cw1200_scan_work(struct work_struct *work)
132 {
133 	struct cw1200_common *priv = container_of(work, struct cw1200_common,
134 							scan.work);
135 	struct ieee80211_channel **it;
136 	struct wsm_scan scan = {
137 		.type = WSM_SCAN_TYPE_FOREGROUND,
138 		.flags = WSM_SCAN_FLAG_SPLIT_METHOD,
139 	};
140 	bool first_run = (priv->scan.begin == priv->scan.curr &&
141 			  priv->scan.begin != priv->scan.end);
142 	int i;
143 
144 	if (first_run) {
145 		/* Firmware gets crazy if scan request is sent
146 		 * when STA is joined but not yet associated.
147 		 * Force unjoin in this case.
148 		 */
149 		if (cancel_delayed_work_sync(&priv->join_timeout) > 0)
150 			cw1200_join_timeout(&priv->join_timeout.work);
151 	}
152 
153 	mutex_lock(&priv->conf_mutex);
154 
155 	if (first_run) {
156 		if (priv->join_status == CW1200_JOIN_STATUS_STA &&
157 		    !(priv->powersave_mode.mode & WSM_PSM_PS)) {
158 			struct wsm_set_pm pm = priv->powersave_mode;
159 			pm.mode = WSM_PSM_PS;
160 			cw1200_set_pm(priv, &pm);
161 		} else if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
162 			/* FW bug: driver has to restart p2p-dev mode
163 			 * after scan
164 			 */
165 			cw1200_disable_listening(priv);
166 		}
167 	}
168 
169 	if (!priv->scan.req || (priv->scan.curr == priv->scan.end)) {
170 		struct cfg80211_scan_info info = {
171 			.aborted = priv->scan.status ? 1 : 0,
172 		};
173 
174 		if (priv->scan.output_power != priv->output_power)
175 			wsm_set_output_power(priv, priv->output_power * 10);
176 		if (priv->join_status == CW1200_JOIN_STATUS_STA &&
177 		    !(priv->powersave_mode.mode & WSM_PSM_PS))
178 			cw1200_set_pm(priv, &priv->powersave_mode);
179 
180 		if (priv->scan.status < 0)
181 			wiphy_warn(priv->hw->wiphy,
182 				   "[SCAN] Scan failed (%d).\n",
183 				   priv->scan.status);
184 		else if (priv->scan.req)
185 			wiphy_dbg(priv->hw->wiphy,
186 				  "[SCAN] Scan completed.\n");
187 		else
188 			wiphy_dbg(priv->hw->wiphy,
189 				  "[SCAN] Scan canceled.\n");
190 
191 		priv->scan.req = NULL;
192 		cw1200_scan_restart_delayed(priv);
193 		wsm_unlock_tx(priv);
194 		mutex_unlock(&priv->conf_mutex);
195 		ieee80211_scan_completed(priv->hw, &info);
196 		up(&priv->scan.lock);
197 		return;
198 	} else {
199 		struct ieee80211_channel *first = *priv->scan.curr;
200 		for (it = priv->scan.curr + 1, i = 1;
201 		     it != priv->scan.end && i < WSM_SCAN_MAX_NUM_OF_CHANNELS;
202 		     ++it, ++i) {
203 			if ((*it)->band != first->band)
204 				break;
205 			if (((*it)->flags ^ first->flags) &
206 					IEEE80211_CHAN_NO_IR)
207 				break;
208 			if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
209 			    (*it)->max_power != first->max_power)
210 				break;
211 		}
212 		scan.band = first->band;
213 
214 		if (priv->scan.req->no_cck)
215 			scan.max_tx_rate = WSM_TRANSMIT_RATE_6;
216 		else
217 			scan.max_tx_rate = WSM_TRANSMIT_RATE_1;
218 		scan.num_probes =
219 			(first->flags & IEEE80211_CHAN_NO_IR) ? 0 : 2;
220 		scan.num_ssids = priv->scan.n_ssids;
221 		scan.ssids = &priv->scan.ssids[0];
222 		scan.num_channels = it - priv->scan.curr;
223 		/* TODO: Is it optimal? */
224 		scan.probe_delay = 100;
225 		/* It is not stated in WSM specification, however
226 		 * FW team says that driver may not use FG scan
227 		 * when joined.
228 		 */
229 		if (priv->join_status == CW1200_JOIN_STATUS_STA) {
230 			scan.type = WSM_SCAN_TYPE_BACKGROUND;
231 			scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
232 		}
233 		scan.ch = kcalloc(it - priv->scan.curr,
234 				  sizeof(struct wsm_scan_ch),
235 				  GFP_KERNEL);
236 		if (!scan.ch) {
237 			priv->scan.status = -ENOMEM;
238 			goto fail;
239 		}
240 		for (i = 0; i < scan.num_channels; ++i) {
241 			scan.ch[i].number = priv->scan.curr[i]->hw_value;
242 			if (priv->scan.curr[i]->flags & IEEE80211_CHAN_NO_IR) {
243 				scan.ch[i].min_chan_time = 50;
244 				scan.ch[i].max_chan_time = 100;
245 			} else {
246 				scan.ch[i].min_chan_time = 10;
247 				scan.ch[i].max_chan_time = 25;
248 			}
249 		}
250 		if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
251 		    priv->scan.output_power != first->max_power) {
252 			priv->scan.output_power = first->max_power;
253 			wsm_set_output_power(priv,
254 					     priv->scan.output_power * 10);
255 		}
256 		priv->scan.status = cw1200_scan_start(priv, &scan);
257 		kfree(scan.ch);
258 		if (priv->scan.status)
259 			goto fail;
260 		priv->scan.curr = it;
261 	}
262 	mutex_unlock(&priv->conf_mutex);
263 	return;
264 
265 fail:
266 	priv->scan.curr = priv->scan.end;
267 	mutex_unlock(&priv->conf_mutex);
268 	queue_work(priv->workqueue, &priv->scan.work);
269 	return;
270 }
271 
272 static void cw1200_scan_restart_delayed(struct cw1200_common *priv)
273 {
274 	/* FW bug: driver has to restart p2p-dev mode after scan. */
275 	if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
276 		cw1200_enable_listening(priv);
277 		cw1200_update_filtering(priv);
278 	}
279 
280 	if (priv->delayed_unjoin) {
281 		priv->delayed_unjoin = false;
282 		if (queue_work(priv->workqueue, &priv->unjoin_work) <= 0)
283 			wsm_unlock_tx(priv);
284 	} else if (priv->delayed_link_loss) {
285 			wiphy_dbg(priv->hw->wiphy, "[CQM] Requeue BSS loss.\n");
286 			priv->delayed_link_loss = 0;
287 			cw1200_cqm_bssloss_sm(priv, 1, 0, 0);
288 	}
289 }
290 
291 static void cw1200_scan_complete(struct cw1200_common *priv)
292 {
293 	queue_delayed_work(priv->workqueue, &priv->clear_recent_scan_work, HZ);
294 	if (priv->scan.direct_probe) {
295 		wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe complete.\n");
296 		cw1200_scan_restart_delayed(priv);
297 		priv->scan.direct_probe = 0;
298 		up(&priv->scan.lock);
299 		wsm_unlock_tx(priv);
300 	} else {
301 		cw1200_scan_work(&priv->scan.work);
302 	}
303 }
304 
305 void cw1200_scan_failed_cb(struct cw1200_common *priv)
306 {
307 	if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
308 		/* STA is stopped. */
309 		return;
310 
311 	if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
312 		priv->scan.status = -EIO;
313 		queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
314 	}
315 }
316 
317 
318 void cw1200_scan_complete_cb(struct cw1200_common *priv,
319 				struct wsm_scan_complete *arg)
320 {
321 	if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
322 		/* STA is stopped. */
323 		return;
324 
325 	if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
326 		priv->scan.status = 1;
327 		queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
328 	}
329 }
330 
331 void cw1200_clear_recent_scan_work(struct work_struct *work)
332 {
333 	struct cw1200_common *priv =
334 		container_of(work, struct cw1200_common,
335 			     clear_recent_scan_work.work);
336 	atomic_xchg(&priv->recent_scan, 0);
337 }
338 
339 void cw1200_scan_timeout(struct work_struct *work)
340 {
341 	struct cw1200_common *priv =
342 		container_of(work, struct cw1200_common, scan.timeout.work);
343 	if (atomic_xchg(&priv->scan.in_progress, 0)) {
344 		if (priv->scan.status > 0) {
345 			priv->scan.status = 0;
346 		} else if (!priv->scan.status) {
347 			wiphy_warn(priv->hw->wiphy,
348 				   "Timeout waiting for scan complete notification.\n");
349 			priv->scan.status = -ETIMEDOUT;
350 			priv->scan.curr = priv->scan.end;
351 			wsm_stop_scan(priv);
352 		}
353 		cw1200_scan_complete(priv);
354 	}
355 }
356 
357 void cw1200_probe_work(struct work_struct *work)
358 {
359 	struct cw1200_common *priv =
360 		container_of(work, struct cw1200_common, scan.probe_work.work);
361 	u8 queue_id = cw1200_queue_get_queue_id(priv->pending_frame_id);
362 	struct cw1200_queue *queue = &priv->tx_queue[queue_id];
363 	const struct cw1200_txpriv *txpriv;
364 	struct wsm_tx *wsm;
365 	struct wsm_template_frame frame = {
366 		.frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
367 	};
368 	struct wsm_ssid ssids[1] = {{
369 		.length = 0,
370 	} };
371 	struct wsm_scan_ch ch[1] = {{
372 		.min_chan_time = 0,
373 		.max_chan_time = 10,
374 	} };
375 	struct wsm_scan scan = {
376 		.type = WSM_SCAN_TYPE_FOREGROUND,
377 		.num_probes = 1,
378 		.probe_delay = 0,
379 		.num_channels = 1,
380 		.ssids = ssids,
381 		.ch = ch,
382 	};
383 	u8 *ies;
384 	size_t ies_len;
385 	int ret;
386 
387 	wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe work.\n");
388 
389 	mutex_lock(&priv->conf_mutex);
390 	if (down_trylock(&priv->scan.lock)) {
391 		/* Scan is already in progress. Requeue self. */
392 		schedule();
393 		queue_delayed_work(priv->workqueue, &priv->scan.probe_work,
394 				   msecs_to_jiffies(100));
395 		mutex_unlock(&priv->conf_mutex);
396 		return;
397 	}
398 
399 	/* Make sure we still have a pending probe req */
400 	if (cw1200_queue_get_skb(queue,	priv->pending_frame_id,
401 				 &frame.skb, &txpriv)) {
402 		up(&priv->scan.lock);
403 		mutex_unlock(&priv->conf_mutex);
404 		wsm_unlock_tx(priv);
405 		return;
406 	}
407 	wsm = (struct wsm_tx *)frame.skb->data;
408 	scan.max_tx_rate = wsm->max_tx_rate;
409 	scan.band = (priv->channel->band == NL80211_BAND_5GHZ) ?
410 		WSM_PHY_BAND_5G : WSM_PHY_BAND_2_4G;
411 	if (priv->join_status == CW1200_JOIN_STATUS_STA ||
412 	    priv->join_status == CW1200_JOIN_STATUS_IBSS) {
413 		scan.type = WSM_SCAN_TYPE_BACKGROUND;
414 		scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
415 	}
416 	ch[0].number = priv->channel->hw_value;
417 
418 	skb_pull(frame.skb, txpriv->offset);
419 
420 	ies = &frame.skb->data[sizeof(struct ieee80211_hdr_3addr)];
421 	ies_len = frame.skb->len - sizeof(struct ieee80211_hdr_3addr);
422 
423 	if (ies_len) {
424 		u8 *ssidie =
425 			(u8 *)cfg80211_find_ie(WLAN_EID_SSID, ies, ies_len);
426 		if (ssidie && ssidie[1] && ssidie[1] <= sizeof(ssids[0].ssid)) {
427 			u8 *nextie = &ssidie[2 + ssidie[1]];
428 			/* Remove SSID from the IE list. It has to be provided
429 			 * as a separate argument in cw1200_scan_start call
430 			 */
431 
432 			/* Store SSID localy */
433 			ssids[0].length = ssidie[1];
434 			memcpy(ssids[0].ssid, &ssidie[2], ssids[0].length);
435 			scan.num_ssids = 1;
436 
437 			/* Remove SSID from IE list */
438 			ssidie[1] = 0;
439 			memmove(&ssidie[2], nextie, &ies[ies_len] - nextie);
440 			skb_trim(frame.skb, frame.skb->len - ssids[0].length);
441 		}
442 	}
443 
444 	/* FW bug: driver has to restart p2p-dev mode after scan */
445 	if (priv->join_status == CW1200_JOIN_STATUS_MONITOR)
446 		cw1200_disable_listening(priv);
447 	ret = wsm_set_template_frame(priv, &frame);
448 	priv->scan.direct_probe = 1;
449 	if (!ret) {
450 		wsm_flush_tx(priv);
451 		ret = cw1200_scan_start(priv, &scan);
452 	}
453 	mutex_unlock(&priv->conf_mutex);
454 
455 	skb_push(frame.skb, txpriv->offset);
456 	if (!ret)
457 		IEEE80211_SKB_CB(frame.skb)->flags |= IEEE80211_TX_STAT_ACK;
458 	BUG_ON(cw1200_queue_remove(queue, priv->pending_frame_id));
459 
460 	if (ret) {
461 		priv->scan.direct_probe = 0;
462 		up(&priv->scan.lock);
463 		wsm_unlock_tx(priv);
464 	}
465 
466 	return;
467 }
468