From: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
To: linux-wireless@vger.kernel.org
Subject: [PATCHv2 14/21] cw1200: scan.*, mac80211 hw_scan callback.
Date: Fri, 2 Mar 2012 21:26:36 +0100
Message-ID: <1330720003-15866-15-git-send-email-dmitry.tarnyagin@stericsson.com> (sfid-20120302_212738_749287_BE794DF7)
In-Reply-To: <1330720003-15866-1-git-send-email-dmitry.tarnyagin@stericsson.com>
References: <983b0e2d75af161b8e4dec02fc3497926a0080df-submit>
 <1330720003-15866-1-git-send-email-dmitry.tarnyagin@stericsson.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-wireless-owner@vger.kernel.org

The code implements mac80211 hw_scan callback.

Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
---
 drivers/net/wireless/cw1200/scan.c |  446 ++++++++++++++++++++++++++++++++++++
 drivers/net/wireless/cw1200/scan.h |   54 +++++
 2 files changed, 500 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/wireless/cw1200/scan.c
 create mode 100644 drivers/net/wireless/cw1200/scan.h

diff --git a/drivers/net/wireless/cw1200/scan.c b/drivers/net/wireless/cw1200/scan.c
new file mode 100644
index 0000000..b12af9d
--- /dev/null
+++ b/drivers/net/wireless/cw1200/scan.c
@@ -0,0 +1,446 @@
+/*
+ * Scan implementation for ST-Ericsson CW1200 mac80211 drivers
+ *
+ * Copyright (c) 2010-2012, ST-Ericsson AB
+ * Author: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
+ *
+ * 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.
+ */
+
+#include <linux/sched.h>
+#include "cw1200.h"
+#include "scan.h"
+#include "sta.h"
+#include "pm.h"
+
+static void cw1200_scan_restart_delayed(struct cw1200_common *priv);
+
+static int cw1200_scan_start(struct cw1200_common *priv, struct wsm_scan *scan)
+{
+	int ret, i;
+	int tmo = 2000;
+
+	for (i = 0; i < scan->numOfChannels; ++i)
+		tmo += scan->ch[i].maxChannelTime + 10;
+
+	atomic_set(&priv->scan.in_progress, 1);
+	cw1200_pm_stay_awake(&priv->pm_state, tmo * HZ / 1000);
+	queue_delayed_work(priv->workqueue, &priv->scan.timeout,
+		tmo * HZ / 1000);
+	ret = wsm_scan(priv, scan);
+	if (unlikely(ret)) {
+		atomic_set(&priv->scan.in_progress, 0);
+		cancel_delayed_work_sync(&priv->scan.timeout);
+		cw1200_scan_restart_delayed(priv);
+	}
+	return ret;
+}
+
+int cw1200_hw_scan(struct ieee80211_hw *hw,
+		   struct ieee80211_vif *vif,
+		   struct cfg80211_scan_request *req)
+{
+	struct cw1200_common *priv = hw->priv;
+	struct wsm_template_frame frame = {
+		.frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
+	};
+	int i;
+
+	if (!priv->vif)
+		return -EINVAL;
+
+	/* Scan when P2P_GO corrupt firmware MiniAP mode */
+	if (priv->join_status == CW1200_JOIN_STATUS_AP)
+		return -EOPNOTSUPP;
+
+	if (req->n_ssids == 1 && !req->ssids[0].ssid_len)
+		req->n_ssids = 0;
+
+	wiphy_dbg(hw->wiphy, "[SCAN] Scan request for %d SSIDs.\n",
+		req->n_ssids);
+
+	if (req->n_ssids > WSM_SCAN_MAX_NUM_OF_SSIDS)
+		return -EINVAL;
+
+	frame.skb = ieee80211_probereq_get(hw, priv->vif, NULL, 0,
+		req->ie, req->ie_len);
+	if (!frame.skb)
+		return -ENOMEM;
+
+	/* will be unlocked in cw1200_scan_work() */
+	down(&priv->scan.lock);
+	mutex_lock(&priv->conf_mutex);
+	if (frame.skb) {
+		int ret = wsm_set_template_frame(priv, &frame);
+		if (0 == ret) {
+			/*
+			* set empty probe response template in order
+			* to receive probe requests from firmware
+			*/
+			frame.frame_type = WSM_FRAME_TYPE_PROBE_RESPONSE;
+			frame.disable = true;
+			ret = wsm_set_template_frame(priv, &frame);
+		}
+		if (ret) {
+			mutex_unlock(&priv->conf_mutex);
+			up(&priv->scan.lock);
+			dev_kfree_skb(frame.skb);
+			return ret;
+		}
+	}
+
+	wsm_lock_tx(priv);
+
+	BUG_ON(priv->scan.req);
+	priv->scan.req = req;
+	priv->scan.n_ssids = 0;
+	priv->scan.status = 0;
+	priv->scan.begin = &req->channels[0];
+	priv->scan.curr = priv->scan.begin;
+	priv->scan.end = &req->channels[req->n_channels];
+	priv->scan.output_power = priv->output_power;
+
+	for (i = 0; i < req->n_ssids; ++i) {
+		struct wsm_ssid *dst =
+			&priv->scan.ssids[priv->scan.n_ssids];
+		BUG_ON(req->ssids[i].ssid_len > sizeof(dst->ssid));
+		memcpy(&dst->ssid[0], req->ssids[i].ssid,
+			sizeof(dst->ssid));
+		dst->length = req->ssids[i].ssid_len;
+		++priv->scan.n_ssids;
+	}
+
+	mutex_unlock(&priv->conf_mutex);
+
+	if (frame.skb)
+		dev_kfree_skb(frame.skb);
+	queue_work(priv->workqueue, &priv->scan.work);
+	return 0;
+}
+
+void cw1200_scan_work(struct work_struct *work)
+{
+	struct cw1200_common *priv = container_of(work, struct cw1200_common,
+							scan.work);
+	struct ieee80211_channel **it;
+	struct wsm_scan scan = {
+		.scanType = WSM_SCAN_TYPE_FOREGROUND,
+		.scanFlags = WSM_SCAN_FLAG_SPLIT_METHOD,
+	};
+	bool first_run = priv->scan.begin == priv->scan.curr &&
+			priv->scan.begin != priv->scan.end;
+	int i;
+
+	if (first_run) {
+		/* Firmware gets crazy if scan request is sent
+		 * when STA is joined but not yet associated.
+		 * Force unjoin in this case. */
+		if (cancel_delayed_work_sync(&priv->join_timeout) > 0)
+			cw1200_join_timeout(&priv->join_timeout.work);
+	}
+
+	mutex_lock(&priv->conf_mutex);
+
+	if (first_run) {
+		if (priv->join_status == CW1200_JOIN_STATUS_STA &&
+				!(priv->powersave_mode.pmMode & WSM_PSM_PS)) {
+			struct wsm_set_pm pm = priv->powersave_mode;
+			pm.pmMode = WSM_PSM_PS;
+			cw1200_set_pm(priv, &pm);
+		} else if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
+			/* FW bug: driver has to restart p2p-dev mode
+			 * after scan */
+			cw1200_disable_listening(priv);
+		}
+	}
+
+	if (!priv->scan.req || (priv->scan.curr == priv->scan.end)) {
+		if (priv->scan.output_power != priv->output_power)
+			WARN_ON(wsm_set_output_power(priv,
+						priv->output_power * 10));
+		if (priv->join_status == CW1200_JOIN_STATUS_STA &&
+				!(priv->powersave_mode.pmMode & WSM_PSM_PS))
+			cw1200_set_pm(priv, &priv->powersave_mode);
+
+		if (priv->scan.status < 0)
+			wiphy_dbg(priv->hw->wiphy,
+					"[SCAN] Scan failed (%d).\n",
+					priv->scan.status);
+		else if (priv->scan.req)
+			wiphy_dbg(priv->hw->wiphy,
+					"[SCAN] Scan completed.\n");
+		else
+			wiphy_dbg(priv->hw->wiphy,
+					"[SCAN] Scan canceled.\n");
+
+		priv->scan.req = NULL;
+		cw1200_scan_restart_delayed(priv);
+		wsm_unlock_tx(priv);
+		mutex_unlock(&priv->conf_mutex);
+		ieee80211_scan_completed(priv->hw, priv->scan.status ? 1 : 0);
+		up(&priv->scan.lock);
+		return;
+	} else {
+		struct ieee80211_channel *first = *priv->scan.curr;
+		for (it = priv->scan.curr + 1, i = 1;
+		     it != priv->scan.end && i < WSM_SCAN_MAX_NUM_OF_CHANNELS;
+		     ++it, ++i) {
+			if ((*it)->band != first->band)
+				break;
+			if (((*it)->flags ^ first->flags) &
+					IEEE80211_CHAN_PASSIVE_SCAN)
+				break;
+			if (!(first->flags & IEEE80211_CHAN_PASSIVE_SCAN) &&
+			    (*it)->max_power != first->max_power)
+				break;
+		}
+		scan.band = first->band;
+
+		if (priv->scan.req->no_cck)
+			scan.maxTransmitRate = WSM_TRANSMIT_RATE_6;
+		else
+			scan.maxTransmitRate = WSM_TRANSMIT_RATE_1;
+		/* TODO: Is it optimal? */
+		scan.numOfProbeRequests =
+			(first->flags & IEEE80211_CHAN_PASSIVE_SCAN) ? 0 : 2;
+		scan.numOfSSIDs = priv->scan.n_ssids;
+		scan.ssids = &priv->scan.ssids[0];
+		scan.numOfChannels = it - priv->scan.curr;
+		/* TODO: Is it optimal? */
+		scan.probeDelay = 100;
+		/* It is not stated in WSM specification, however
+		 * FW team says that driver may not use FG scan
+		 * when joined. */
+		if (priv->join_status == CW1200_JOIN_STATUS_STA) {
+			scan.scanType = WSM_SCAN_TYPE_BACKGROUND;
+			scan.scanFlags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
+		}
+		scan.ch = kzalloc(
+			sizeof(struct wsm_scan_ch[it - priv->scan.curr]),
+			GFP_KERNEL);
+		if (!scan.ch) {
+			priv->scan.status = -ENOMEM;
+			goto fail;
+		}
+		for (i = 0; i < scan.numOfChannels; ++i) {
+			scan.ch[i].number = priv->scan.curr[i]->hw_value;
+			scan.ch[i].minChannelTime = 50;
+			scan.ch[i].maxChannelTime = 110;
+		}
+		if (!(first->flags & IEEE80211_CHAN_PASSIVE_SCAN) &&
+		    priv->scan.output_power != first->max_power) {
+			priv->scan.output_power = first->max_power;
+			WARN_ON(wsm_set_output_power(priv,
+						priv->scan.output_power * 10));
+		}
+		priv->scan.status = cw1200_scan_start(priv, &scan);
+		kfree(scan.ch);
+		if (priv->scan.status)
+			goto fail;
+		priv->scan.curr = it;
+	}
+	mutex_unlock(&priv->conf_mutex);
+	return;
+
+fail:
+	priv->scan.curr = priv->scan.end;
+	mutex_unlock(&priv->conf_mutex);
+	queue_work(priv->workqueue, &priv->scan.work);
+	return;
+}
+
+static void cw1200_scan_restart_delayed(struct cw1200_common *priv)
+{
+	if (priv->delayed_link_loss) {
+		int tmo = priv->cqm_beacon_loss_count;
+
+		if (priv->scan.direct_probe)
+			tmo = 0;
+
+		priv->delayed_link_loss = 0;
+		/* Restart beacon loss timer and requeue
+		   BSS loss work. */
+		wiphy_dbg(priv->hw->wiphy,
+				"[CQM] Requeue BSS loss in %d "
+				"beacons.\n", tmo);
+		spin_lock(&priv->bss_loss_lock);
+		priv->bss_loss_status = CW1200_BSS_LOSS_NONE;
+		spin_unlock(&priv->bss_loss_lock);
+		cancel_delayed_work_sync(&priv->bss_loss_work);
+		queue_delayed_work(priv->workqueue,
+				&priv->bss_loss_work,
+				tmo * HZ / 10);
+	}
+
+	/* FW bug: driver has to restart p2p-dev mode after scan. */
+	if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
+		cw1200_enable_listening(priv);
+		cw1200_update_filtering(priv);
+	}
+
+	if (priv->delayed_unjoin) {
+		priv->delayed_unjoin = false;
+		if (queue_work(priv->workqueue, &priv->unjoin_work) <= 0)
+			wsm_unlock_tx(priv);
+	}
+}
+
+static void cw1200_scan_complete(struct cw1200_common *priv)
+{
+	if (priv->scan.direct_probe) {
+		wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe complete.\n");
+		cw1200_scan_restart_delayed(priv);
+		priv->scan.direct_probe = 0;
+		up(&priv->scan.lock);
+		wsm_unlock_tx(priv);
+	} else {
+		cw1200_scan_work(&priv->scan.work);
+	}
+}
+
+void cw1200_scan_complete_cb(struct cw1200_common *priv,
+				struct wsm_scan_complete *arg)
+{
+	if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED))
+		/* STA is stopped. */
+		return;
+
+	if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
+		priv->scan.status = 1;
+		queue_delayed_work(priv->workqueue,
+				&priv->scan.timeout, 0);
+	}
+}
+
+void cw1200_scan_timeout(struct work_struct *work)
+{
+	struct cw1200_common *priv =
+		container_of(work, struct cw1200_common, scan.timeout.work);
+	if (likely(atomic_xchg(&priv->scan.in_progress, 0))) {
+		if (priv->scan.status > 0)
+			priv->scan.status = 0;
+		else if (!priv->scan.status) {
+			wiphy_warn(priv->hw->wiphy,
+				"Timeout waiting for scan "
+				"complete notification.\n");
+			priv->scan.status = -ETIMEDOUT;
+			priv->scan.curr = priv->scan.end;
+			WARN_ON(wsm_stop_scan(priv));
+		}
+		cw1200_scan_complete(priv);
+	}
+}
+
+void cw1200_probe_work(struct work_struct *work)
+{
+	struct cw1200_common *priv =
+		container_of(work, struct cw1200_common, scan.probe_work.work);
+	u8 queueId = cw1200_queue_get_queue_id(priv->pending_frame_id);
+	struct cw1200_queue *queue = &priv->tx_queue[queueId];
+	const struct cw1200_txpriv *txpriv;
+	struct wsm_tx *wsm;
+	struct wsm_template_frame frame = {
+		.frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
+	};
+	struct wsm_ssid ssids[1] = {{
+		.length = 0,
+	} };
+	struct wsm_scan_ch ch[1] = {{
+		.minChannelTime = 0,
+		.maxChannelTime = 10,
+	} };
+	struct wsm_scan scan = {
+		.scanType = WSM_SCAN_TYPE_FOREGROUND,
+		.numOfProbeRequests = 1,
+		.probeDelay = 0,
+		.numOfChannels = 1,
+		.ssids = ssids,
+		.ch = ch,
+	};
+	u8 *ies;
+	size_t ies_len;
+	int ret;
+
+	wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe work.\n");
+
+	BUG_ON(queueId >= 4);
+	BUG_ON(!priv->channel);
+
+	mutex_lock(&priv->conf_mutex);
+	if (unlikely(down_trylock(&priv->scan.lock))) {
+		/* Scan is already in progress. Requeue self. */
+		schedule();
+		queue_delayed_work(priv->workqueue,
+					&priv->scan.probe_work, HZ / 10);
+		mutex_unlock(&priv->conf_mutex);
+		return;
+	}
+
+	if (cw1200_queue_get_skb(queue,	priv->pending_frame_id,
+			&frame.skb, &txpriv)) {
+		up(&priv->scan.lock);
+		mutex_unlock(&priv->conf_mutex);
+		wsm_unlock_tx(priv);
+		return;
+	}
+	wsm = (struct wsm_tx *)frame.skb->data;
+	scan.maxTransmitRate = wsm->maxTxRate;
+	scan.band = (priv->channel->band == IEEE80211_BAND_5GHZ) ?
+		WSM_PHY_BAND_5G : WSM_PHY_BAND_2_4G;
+	if (priv->join_status == CW1200_JOIN_STATUS_STA) {
+		scan.scanType = WSM_SCAN_TYPE_BACKGROUND;
+		scan.scanFlags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
+	}
+	ch[0].number = priv->channel->hw_value;
+
+	skb_pull(frame.skb, txpriv->offset);
+
+	ies = &frame.skb->data[sizeof(struct ieee80211_hdr_3addr)];
+	ies_len = frame.skb->len - sizeof(struct ieee80211_hdr_3addr);
+
+	if (ies_len) {
+		u8 *ssidie =
+			(u8 *)cfg80211_find_ie(WLAN_EID_SSID, ies, ies_len);
+		if (ssidie && ssidie[1] && ssidie[1] <= sizeof(ssids[0].ssid)) {
+			u8 *nextie = &ssidie[2 + ssidie[1]];
+			/* Remove SSID from the IE list. It has to be provided
+			 * as a separate argument in cw1200_scan_start call */
+
+			/* Store SSID localy */
+			ssids[0].length = ssidie[1];
+			memcpy(ssids[0].ssid, &ssidie[2], ssids[0].length);
+			scan.numOfSSIDs = 1;
+
+			/* Remove SSID from IE list */
+			ssidie[1] = 0;
+			memmove(&ssidie[2], nextie, &ies[ies_len] - nextie);
+			skb_trim(frame.skb, frame.skb->len - ssids[0].length);
+		}
+	}
+
+	/* FW bug: driver has to restart p2p-dev mode after scan */
+	if (priv->join_status == CW1200_JOIN_STATUS_MONITOR)
+		cw1200_disable_listening(priv);
+	ret = WARN_ON(wsm_set_template_frame(priv, &frame));
+	priv->scan.direct_probe = 1;
+	if (!ret) {
+		wsm_flush_tx(priv);
+		ret = WARN_ON(cw1200_scan_start(priv, &scan));
+	}
+	mutex_unlock(&priv->conf_mutex);
+
+	skb_push(frame.skb, txpriv->offset);
+	if (!ret)
+		IEEE80211_SKB_CB(frame.skb)->flags |= IEEE80211_TX_STAT_ACK;
+	BUG_ON(cw1200_queue_remove(queue, priv->pending_frame_id));
+
+	if (ret) {
+		priv->scan.direct_probe = 0;
+		up(&priv->scan.lock);
+		wsm_unlock_tx(priv);
+	}
+
+	return;
+}
diff --git a/drivers/net/wireless/cw1200/scan.h b/drivers/net/wireless/cw1200/scan.h
new file mode 100644
index 0000000..abffd1d
--- /dev/null
+++ b/drivers/net/wireless/cw1200/scan.h
@@ -0,0 +1,54 @@
+/*
+ * Scan interface for ST-Ericsson CW1200 mac80211 drivers
+ *
+ * Copyright (c) 2010-2012, ST-Ericsson AB
+ * Author: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
+ *
+ * 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.
+ */
+
+#ifndef SCAN_H_INCLUDED
+#define SCAN_H_INCLUDED
+
+#include <linux/semaphore.h>
+#include "wsm.h"
+
+/* external */ struct sk_buff;
+/* external */ struct cfg80211_scan_request;
+/* external */ struct ieee80211_channel;
+/* external */ struct ieee80211_hw;
+/* external */ struct work_struct;
+
+struct cw1200_scan {
+	struct semaphore lock;
+	struct work_struct work;
+	struct delayed_work timeout;
+	struct cfg80211_scan_request *req;
+	struct ieee80211_channel **begin;
+	struct ieee80211_channel **curr;
+	struct ieee80211_channel **end;
+	struct wsm_ssid ssids[WSM_SCAN_MAX_NUM_OF_SSIDS];
+	int output_power;
+	int n_ssids;
+	int status;
+	atomic_t in_progress;
+	/* Direct probe requests workaround */
+	struct delayed_work probe_work;
+	int direct_probe;
+};
+
+int cw1200_hw_scan(struct ieee80211_hw *hw,
+			struct ieee80211_vif *vif,
+			struct cfg80211_scan_request *req);
+void cw1200_scan_work(struct work_struct *work);
+void cw1200_scan_timeout(struct work_struct *work);
+void cw1200_scan_complete_cb(struct cw1200_common *priv,
+				struct wsm_scan_complete *arg);
+
+/* ******************************************************************** */
+/* Raw probe requests TX workaround					*/
+void cw1200_probe_work(struct work_struct *work);
+
+#endif
-- 
1.7.9