p54: improve site survey

The firmware keeps track of channel usage. This data can
be used by the automatic channel selection to find the best
channel.

Survey data from wlan4
	frequency:				5200 MHz [in use]
	noise:					-91 dBm
	channel active time:			811909 ms
	channel busy time:			63395 ms
	channel transmit time:			59636 ms
Survey data from wlan4
	frequency:				5210 MHz
	noise:					-91 dBm
	channel active time:			121 ms
	channel busy time:			119 ms
	channel transmit time:			0 ms

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 211 insertions, 14 deletions

diff --git a/drivers/net/wireless/p54/eeprom.c b/drivers/net/wireless/p54/eeprom.c
index 54cc0bba66b9..8b6f363b3f7d 100644
--- a/drivers/net/wireless/p54/eeprom.c
+++ b/drivers/net/wireless/p54/eeprom.c
@@ -145,6 +145,7 @@ static int p54_fill_band_bitrates(struct ieee80211_hw *dev,
 
 static int p54_generate_band(struct ieee80211_hw *dev,
                              struct p54_channel_list *list,
+                             unsigned int *chan_num,
                              enum ieee80211_band band)
 {
         struct p54_common *priv = dev->priv;
@@ -190,7 +191,14 @@ static int p54_generate_band(struct ieee80211_hw *dev,
 
                 tmp->channels[j].band = chan->band;
                 tmp->channels[j].center_freq = chan->freq;
+                priv->survey[*chan_num].channel = &tmp->channels[j];
+                priv->survey[*chan_num].filled = SURVEY_INFO_NOISE_DBM |
+                        SURVEY_INFO_CHANNEL_TIME |
+                        SURVEY_INFO_CHANNEL_TIME_BUSY |
+                        SURVEY_INFO_CHANNEL_TIME_TX;
+                tmp->channels[j].hw_value = (*chan_num);
                 j++;
+                (*chan_num)++;
         }
 
         if (j == 0) {
@@ -263,7 +271,7 @@ static int p54_generate_channel_lists(struct ieee80211_hw *dev)
 {
         struct p54_common *priv = dev->priv;
         struct p54_channel_list *list;
-        unsigned int i, j, max_channel_num;
+        unsigned int i, j, k, max_channel_num;
         int ret = 0;
         u16 freq;
 
@@ -283,6 +291,13 @@ static int p54_generate_channel_lists(struct ieee80211_hw *dev)
                 ret = -ENOMEM;
                 goto free;
         }
+        priv->chan_num = max_channel_num;
+        priv->survey = kzalloc(sizeof(struct survey_info) * max_channel_num,
+                               GFP_KERNEL);
+        if (!priv->survey) {
+                ret = -ENOMEM;
+                goto free;
+        }
 
         list->max_entries = max_channel_num;
         list->channels = kzalloc(sizeof(struct p54_channel_entry) *
@@ -321,8 +336,9 @@ static int p54_generate_channel_lists(struct ieee80211_hw *dev)
         sort(list->channels, list->entries, sizeof(struct p54_channel_entry),
              p54_compare_channels, NULL);
 
+        k = 0;
         for (i = 0, j = 0; i < IEEE80211_NUM_BANDS; i++) {
-                if (p54_generate_band(dev, list, i) == 0)
+                if (p54_generate_band(dev, list, &k, i) == 0)
                         j++;
         }
         if (j == 0) {
@@ -335,6 +351,10 @@ free:
                 kfree(list->channels);
                 kfree(list);
         }
+        if (ret) {
+                kfree(priv->survey);
+                priv->survey = NULL;
+        }
 
         return ret;
 }
@@ -853,10 +873,12 @@ err:
         kfree(priv->output_limit);
         kfree(priv->curve_data);
         kfree(priv->rssi_db);
+        kfree(priv->survey);
         priv->iq_autocal = NULL;
         priv->output_limit = NULL;
         priv->curve_data = NULL;
         priv->rssi_db = NULL;
+        priv->survey = NULL;
 
         wiphy_err(dev->wiphy, "eeprom parse failed!\n");
         return err;
diff --git a/drivers/net/wireless/p54/fwio.c b/drivers/net/wireless/p54/fwio.c
index b6a061cbbdec..53a3408931be 100644
--- a/drivers/net/wireless/p54/fwio.c
+++ b/drivers/net/wireless/p54/fwio.c
@@ -385,6 +385,7 @@ int p54_setup_mac(struct p54_common *priv)
                 setup->v2.osc_start_delay = cpu_to_le16(65535);
         }
         p54_tx(priv, skb);
+        priv->phy_idle = mode == P54_FILTER_TYPE_HIBERNATE;
         return 0;
 }
 
@@ -626,6 +627,7 @@ int p54_set_ps(struct p54_common *priv)
         psm->exclude[0] = WLAN_EID_TIM;
 
         p54_tx(priv, skb);
+        priv->phy_ps = mode != P54_PSM_CAM;
         return 0;
 }
 
diff --git a/drivers/net/wireless/p54/main.c b/drivers/net/wireless/p54/main.c
index a5a6d9e647bb..726a9343f514 100644
--- a/drivers/net/wireless/p54/main.c
+++ b/drivers/net/wireless/p54/main.c
@@ -204,13 +204,11 @@ static void p54_stop(struct ieee80211_hw *dev)
         struct p54_common *priv = dev->priv;
         int i;
 
-        mutex_lock(&priv->conf_mutex);
         priv->mode = NL80211_IFTYPE_UNSPECIFIED;
         priv->softled_state = 0;
-        p54_set_leds(priv);
-
         cancel_delayed_work_sync(&priv->work);
-
+        mutex_lock(&priv->conf_mutex);
+        p54_set_leds(priv);
         priv->stop(dev);
         skb_queue_purge(&priv->tx_pending);
         skb_queue_purge(&priv->tx_queue);
@@ -278,6 +276,42 @@ static void p54_remove_interface(struct ieee80211_hw *dev,
         mutex_unlock(&priv->conf_mutex);
 }
 
+static int p54_wait_for_stats(struct ieee80211_hw *dev)
+{
+        struct p54_common *priv = dev->priv;
+        int ret;
+
+        priv->update_stats = true;
+        ret = p54_fetch_statistics(priv);
+        if (ret)
+                return ret;
+
+        ret = wait_for_completion_interruptible_timeout(&priv->stat_comp, HZ);
+        if (ret == 0)
+                return -ETIMEDOUT;
+
+        return 0;
+}
+
+static void p54_reset_stats(struct p54_common *priv)
+{
+        struct ieee80211_channel *chan = priv->curchan;
+
+        if (chan) {
+                struct survey_info *info = &priv->survey[chan->hw_value];
+
+                /* only reset channel statistics, don't touch .filled, etc. */
+                info->channel_time = 0;
+                info->channel_time_busy = 0;
+                info->channel_time_tx = 0;
+        }
+
+        priv->update_stats = true;
+        priv->survey_raw.active = 0;
+        priv->survey_raw.cca = 0;
+        priv->survey_raw.tx = 0;
+}
+
 static int p54_config(struct ieee80211_hw *dev, u32 changed)
 {
         int ret = 0;
@@ -288,19 +322,36 @@ static int p54_config(struct ieee80211_hw *dev, u32 changed)
         if (changed & IEEE80211_CONF_CHANGE_POWER)
                 priv->output_power = conf->power_level << 2;
         if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
+                struct ieee80211_channel *oldchan;
+                WARN_ON(p54_wait_for_stats(dev));
+                oldchan = priv->curchan;
+                priv->curchan = NULL;
                 ret = p54_scan(priv, P54_SCAN_EXIT, 0);
-                if (ret)
+                if (ret) {
+                        priv->curchan = oldchan;
                         goto out;
+                }
+                /*
+                 * TODO: Use the LM_SCAN_TRAP to determine the current
+                 * operating channel.
+                 */
+                priv->curchan = priv->hw->conf.channel;
+                p54_reset_stats(priv);
+                WARN_ON(p54_fetch_statistics(priv));
         }
         if (changed & IEEE80211_CONF_CHANGE_PS) {
+                WARN_ON(p54_wait_for_stats(dev));
                 ret = p54_set_ps(priv);
                 if (ret)
                         goto out;
+                WARN_ON(p54_wait_for_stats(dev));
         }
         if (changed & IEEE80211_CONF_CHANGE_IDLE) {
+                WARN_ON(p54_wait_for_stats(dev));
                 ret = p54_setup_mac(priv);
                 if (ret)
                         goto out;
+                WARN_ON(p54_wait_for_stats(dev));
         }
 
 out:
@@ -384,7 +435,9 @@ static void p54_work(struct work_struct *work)
          *      2. cancel stuck frames / reset the device if necessary.
          */
 
-        p54_fetch_statistics(priv);
+        mutex_lock(&priv->conf_mutex);
+        WARN_ON_ONCE(p54_fetch_statistics(priv));
+        mutex_unlock(&priv->conf_mutex);
 }
 
 static int p54_get_stats(struct ieee80211_hw *dev,
@@ -541,16 +594,47 @@ static int p54_get_survey(struct ieee80211_hw *dev, int idx,
                                 struct survey_info *survey)
 {
         struct p54_common *priv = dev->priv;
-        struct ieee80211_conf *conf = &dev->conf;
+        struct ieee80211_channel *chan;
+        int err, tries;
+        bool in_use = false;
 
-        if (idx != 0)
+        if (idx >= priv->chan_num)
                 return -ENOENT;
 
-        survey->channel = conf->channel;
-        survey->filled = SURVEY_INFO_NOISE_DBM;
-        survey->noise = clamp_t(s8, priv->noise, -128, 127);
+#define MAX_TRIES 1
+        for (tries = 0; tries < MAX_TRIES; tries++) {
+                chan = priv->curchan;
+                if (chan && chan->hw_value == idx) {
+                        mutex_lock(&priv->conf_mutex);
+                        err = p54_wait_for_stats(dev);
+                        mutex_unlock(&priv->conf_mutex);
+                        if (err)
+                                return err;
+
+                        in_use = true;
+                }
 
-        return 0;
+                memcpy(survey, &priv->survey[idx], sizeof(*survey));
+
+                if (in_use) {
+                        /* test if the reported statistics are valid. */
+                        if  (survey->channel_time != 0) {
+                                survey->filled |= SURVEY_INFO_IN_USE;
+                        } else {
+                                /*
+                                 * hw/fw has not accumulated enough sample sets.
+                                 * Wait for 100ms, this ought to be enough to
+                                 * to get at least one non-null set of channel
+                                 * usage statistics.
+                                 */
+                                msleep(100);
+                                continue;
+                        }
+                }
+                return 0;
+        }
+        return -ETIMEDOUT;
+#undef MAX_TRIES
 }
 
 static unsigned int p54_flush_count(struct p54_common *priv)
@@ -686,11 +770,14 @@ struct ieee80211_hw *p54_init_common(size_t priv_data_len)
 
         mutex_init(&priv->conf_mutex);
         mutex_init(&priv->eeprom_mutex);
+        init_completion(&priv->stat_comp);
         init_completion(&priv->eeprom_comp);
         init_completion(&priv->beacon_comp);
         INIT_DELAYED_WORK(&priv->work, p54_work);
 
         memset(&priv->mc_maclist[0], ~0, ETH_ALEN);
+        priv->curchan = NULL;
+        p54_reset_stats(priv);
         return dev;
 }
 EXPORT_SYMBOL_GPL(p54_init_common);
@@ -730,11 +817,13 @@ void p54_free_common(struct ieee80211_hw *dev)
         kfree(priv->curve_data);
         kfree(priv->rssi_db);
         kfree(priv->used_rxkeys);
+        kfree(priv->survey);
         priv->iq_autocal = NULL;
         priv->output_limit = NULL;
         priv->curve_data = NULL;
         priv->rssi_db = NULL;
         priv->used_rxkeys = NULL;
+        priv->survey = NULL;
         ieee80211_free_hw(dev);
 }
 EXPORT_SYMBOL_GPL(p54_free_common);
diff --git a/drivers/net/wireless/p54/p54.h b/drivers/net/wireless/p54/p54.h
index 799d05e12595..452fa3a64aa1 100644
--- a/drivers/net/wireless/p54/p54.h
+++ b/drivers/net/wireless/p54/p54.h
@@ -199,6 +199,22 @@ struct p54_common {
         u8 tx_diversity_mask;
         unsigned int output_power;
         struct p54_rssi_db_entry *cur_rssi;
+        struct ieee80211_channel *curchan;
+        struct survey_info *survey;
+        unsigned int chan_num;
+        struct completion stat_comp;
+        bool update_stats;
+        struct {
+                unsigned int timestamp;
+                unsigned int cached_cca;
+                unsigned int cached_tx;
+                unsigned int cached_rssi;
+                u64 active;
+                u64 cca;
+                u64 tx;
+                u64 rssi;
+        } survey_raw;
+
         int noise;
         /* calibration, output power limit and rssi<->dBm conversation data */
         struct pda_iq_autocal_entry *iq_autocal;
@@ -220,6 +236,8 @@ struct p54_common {
         u32 basic_rate_mask;
         u16 aid;
         u8 coverage_class;
+        bool phy_idle;
+        bool phy_ps;
         bool powersave_override;
         __le32 beacon_req_id;
         struct completion beacon_comp;
diff --git a/drivers/net/wireless/p54/txrx.c b/drivers/net/wireless/p54/txrx.c
index 042842e704de..44a3bd4b0f43 100644
--- a/drivers/net/wireless/p54/txrx.c
+++ b/drivers/net/wireless/p54/txrx.c
@@ -507,6 +507,8 @@ static void p54_rx_stats(struct p54_common *priv, struct sk_buff *skb)
         struct p54_hdr *hdr = (struct p54_hdr *) skb->data;
         struct p54_statistics *stats = (struct p54_statistics *) hdr->data;
         struct sk_buff *tmp;
+        struct ieee80211_channel *chan;
+        unsigned int i, rssi, tx, cca, dtime, dtotal, dcca, dtx, drssi, unit;
         u32 tsf32;
 
         if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED))
@@ -523,8 +525,72 @@ static void p54_rx_stats(struct p54_common *priv, struct sk_buff *skb)
 
         priv->noise = p54_rssi_to_dbm(priv, le32_to_cpu(stats->noise));
 
+        /*
+         * STSW450X LMAC API page 26 - 3.8 Statistics
+         * "The exact measurement period can be derived from the
+         * timestamp member".
+         */
+        dtime = tsf32 - priv->survey_raw.timestamp;
+
+        /*
+         * STSW450X LMAC API page 26 - 3.8.1 Noise histogram
+         * The LMAC samples RSSI, CCA and transmit state at regular
+         * periods (typically 8 times per 1k [as in 1024] usec).
+         */
+        cca = le32_to_cpu(stats->sample_cca);
+        tx = le32_to_cpu(stats->sample_tx);
+        rssi = 0;
+        for (i = 0; i < ARRAY_SIZE(stats->sample_noise); i++)
+                rssi += le32_to_cpu(stats->sample_noise[i]);
+
+        dcca = cca - priv->survey_raw.cached_cca;
+        drssi = rssi - priv->survey_raw.cached_rssi;
+        dtx = tx - priv->survey_raw.cached_tx;
+        dtotal = dcca + drssi + dtx;
+
+        /*
+         * update statistics when more than a second is over since the
+         * last call, or when a update is badly needed.
+         */
+        if (dtotal && (priv->update_stats || dtime >= USEC_PER_SEC) &&
+            dtime >= dtotal) {
+                priv->survey_raw.timestamp = tsf32;
+                priv->update_stats = false;
+                unit = dtime / dtotal;
+
+                if (dcca) {
+                        priv->survey_raw.cca += dcca * unit;
+                        priv->survey_raw.cached_cca = cca;
+                }
+                if (dtx) {
+                        priv->survey_raw.tx += dtx * unit;
+                        priv->survey_raw.cached_tx = tx;
+                }
+                if (drssi) {
+                        priv->survey_raw.rssi += drssi * unit;
+                        priv->survey_raw.cached_rssi = rssi;
+                }
+
+                /* 1024 usec / 8 times = 128 usec / time */
+                if (!(priv->phy_ps || priv->phy_idle))
+                        priv->survey_raw.active += dtotal * unit;
+                else
+                        priv->survey_raw.active += (dcca + dtx) * unit;
+        }
+
+        chan = priv->curchan;
+        if (chan) {
+                struct survey_info *survey = &priv->survey[chan->hw_value];
+                survey->noise = clamp_t(s8, priv->noise, -128, 127);
+                survey->channel_time = priv->survey_raw.active / 1024;
+                survey->channel_time_tx = priv->survey_raw.tx / 1024;
+                survey->channel_time_busy = priv->survey_raw.cca / 1024 +
+                        survey->channel_time_tx;
+        }
+
         tmp = p54_find_and_unlink_skb(priv, hdr->req_id);
         dev_kfree_skb_any(tmp);
+        complete(&priv->stat_comp);
 }
 
 static void p54_rx_trap(struct p54_common *priv, struct sk_buff *skb)