carl9170: 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 wlan22
	frequency:                      2412 MHz [in use]
	noise:                          -86 dBm
	channel active time:            3339608 ms
	channel busy time:              270982 ms
	channel transmit time:          121515 ms
Survey data from wlan22
	frequency:                      2417 MHz
	noise:                          -86 dBm
	channel active time:            70 ms
	channel busy time:              2 ms
	channel transmit time:          1 ms

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

5 files changed, 153 insertions, 15 deletions

diff --git a/drivers/net/wireless/ath/carl9170/carl9170.h b/drivers/net/wireless/ath/carl9170/carl9170.h
index f7dbdaa74c63..74350d63f686 100644
--- a/drivers/net/wireless/ath/carl9170/carl9170.h
+++ b/drivers/net/wireless/ath/carl9170/carl9170.h
@@ -151,6 +151,7 @@ struct carl9170_sta_tid {
 #define CARL9170_TX_TIMEOUT             2500
 #define CARL9170_JANITOR_DELAY          128
 #define CARL9170_QUEUE_STUCK_TIMEOUT    5500
+#define CARL9170_STAT_WORK              30000
 
 #define CARL9170_NUM_TX_AGG_MAX         30
 
@@ -332,11 +333,21 @@ struct ar9170 {
 
         /* PHY */
         struct ieee80211_channel *channel;
+        unsigned int num_channels;
         int noise[4];
         unsigned int chan_fail;
         unsigned int total_chan_fail;
         u8 heavy_clip;
         u8 ht_settings;
+        struct {
+                u64 active;     /* usec */
+                u64 cca;        /* usec */
+                u64 tx_time;    /* usec */
+                u64 rx_total;
+                u64 rx_overrun;
+        } tally;
+        struct delayed_work stat_work;
+        struct survey_info *survey;
 
         /* power calibration data */
         u8 power_5G_leg[4];
diff --git a/drivers/net/wireless/ath/carl9170/cmd.c b/drivers/net/wireless/ath/carl9170/cmd.c
index cdfc94c371b4..9970bf8edc40 100644
--- a/drivers/net/wireless/ath/carl9170/cmd.c
+++ b/drivers/net/wireless/ath/carl9170/cmd.c
@@ -165,6 +165,37 @@ int carl9170_bcn_ctrl(struct ar9170 *ar, const unsigned int vif_id,
         return __carl9170_exec_cmd(ar, cmd, true);
 }
 
+int carl9170_collect_tally(struct ar9170 *ar)
+{
+        struct carl9170_tally_rsp tally;
+        struct survey_info *info;
+        unsigned int tick;
+        int err;
+
+        err = carl9170_exec_cmd(ar, CARL9170_CMD_TALLY, 0, NULL,
+                                sizeof(tally), (u8 *)&tally);
+        if (err)
+                return err;
+
+        tick = le32_to_cpu(tally.tick);
+        if (tick) {
+                ar->tally.active += le32_to_cpu(tally.active) / tick;
+                ar->tally.cca += le32_to_cpu(tally.cca) / tick;
+                ar->tally.tx_time += le32_to_cpu(tally.tx_time) / tick;
+                ar->tally.rx_total += le32_to_cpu(tally.rx_total);
+                ar->tally.rx_overrun += le32_to_cpu(tally.rx_overrun);
+
+                if (ar->channel) {
+                        info = &ar->survey[ar->channel->hw_value];
+
+                        info->channel_time = ar->tally.active / 1000;
+                        info->channel_time_busy = ar->tally.cca / 1000;
+                        info->channel_time_tx = ar->tally.tx_time / 1000;
+                }
+        }
+        return 0;
+}
+
 int carl9170_powersave(struct ar9170 *ar, const bool ps)
 {
         struct carl9170_cmd *cmd;
diff --git a/drivers/net/wireless/ath/carl9170/cmd.h b/drivers/net/wireless/ath/carl9170/cmd.h
index d5f95bdc75c1..885c42778b8b 100644
--- a/drivers/net/wireless/ath/carl9170/cmd.h
+++ b/drivers/net/wireless/ath/carl9170/cmd.h
@@ -50,6 +50,7 @@ int carl9170_echo_test(struct ar9170 *ar, u32 v);
 int carl9170_reboot(struct ar9170 *ar);
 int carl9170_mac_reset(struct ar9170 *ar);
 int carl9170_powersave(struct ar9170 *ar, const bool power_on);
+int carl9170_collect_tally(struct ar9170 *ar);
 int carl9170_bcn_ctrl(struct ar9170 *ar, const unsigned int vif_id,
                        const u32 mode, const u32 addr, const u32 len);
 
diff --git a/drivers/net/wireless/ath/carl9170/main.c b/drivers/net/wireless/ath/carl9170/main.c
index 0122930b14c7..85cb1bdebaaa 100644
--- a/drivers/net/wireless/ath/carl9170/main.c
+++ b/drivers/net/wireless/ath/carl9170/main.c
@@ -413,6 +413,9 @@ static int carl9170_op_start(struct ieee80211_hw *hw)
 
         carl9170_set_state_when(ar, CARL9170_IDLE, CARL9170_STARTED);
 
+        ieee80211_queue_delayed_work(ar->hw, &ar->stat_work,
+                round_jiffies(msecs_to_jiffies(CARL9170_STAT_WORK)));
+
         ieee80211_wake_queues(ar->hw);
         err = 0;
 
@@ -423,6 +426,7 @@ out:
 
 static void carl9170_cancel_worker(struct ar9170 *ar)
 {
+        cancel_delayed_work_sync(&ar->stat_work);
         cancel_delayed_work_sync(&ar->tx_janitor);
 #ifdef CONFIG_CARL9170_LEDS
         cancel_delayed_work_sync(&ar->led_work);
@@ -794,6 +798,43 @@ static void carl9170_ps_work(struct work_struct *work)
         mutex_unlock(&ar->mutex);
 }
 
+static int carl9170_update_survey(struct ar9170 *ar, bool flush, bool noise)
+{
+        int err;
+
+        if (noise) {
+                err = carl9170_get_noisefloor(ar);
+                if (err)
+                        return err;
+        }
+
+        if (ar->fw.hw_counters) {
+                err = carl9170_collect_tally(ar);
+                if (err)
+                        return err;
+        }
+
+        if (flush)
+                memset(&ar->tally, 0, sizeof(ar->tally));
+
+        return 0;
+}
+
+static void carl9170_stat_work(struct work_struct *work)
+{
+        struct ar9170 *ar = container_of(work, struct ar9170, stat_work.work);
+        int err;
+
+        mutex_lock(&ar->mutex);
+        err = carl9170_update_survey(ar, false, true);
+        mutex_unlock(&ar->mutex);
+
+        if (err)
+                return;
+
+        ieee80211_queue_delayed_work(ar->hw, &ar->stat_work,
+                round_jiffies(msecs_to_jiffies(CARL9170_STAT_WORK)));
+}
 
 static int carl9170_op_config(struct ieee80211_hw *hw, u32 changed)
 {
@@ -828,11 +869,19 @@ static int carl9170_op_config(struct ieee80211_hw *hw, u32 changed)
                 if (err)
                         goto out;
 
+                err = carl9170_update_survey(ar, true, false);
+                if (err)
+                        goto out;
+
                 err = carl9170_set_channel(ar, hw->conf.channel,
                         hw->conf.channel_type, CARL9170_RFI_NONE);
                 if (err)
                         goto out;
 
+                err = carl9170_update_survey(ar, false, true);
+                if (err)
+                        goto out;
+
                 err = carl9170_set_dyn_sifs_ack(ar);
                 if (err)
                         goto out;
@@ -1423,20 +1472,52 @@ static int carl9170_op_get_survey(struct ieee80211_hw *hw, int idx,
                                 struct survey_info *survey)
 {
         struct ar9170 *ar = hw->priv;
-        int err;
+        struct ieee80211_channel *chan;
+        struct ieee80211_supported_band *band;
+        int err, b, i;
 
-        if (idx != 0)
-                return -ENOENT;
+        chan = ar->channel;
+        if (!chan)
+                return -ENODEV;
 
-        mutex_lock(&ar->mutex);
-        err = carl9170_get_noisefloor(ar);
-        mutex_unlock(&ar->mutex);
-        if (err)
-                return err;
+        if (idx == chan->hw_value) {
+                mutex_lock(&ar->mutex);
+                err = carl9170_update_survey(ar, false, true);
+                mutex_unlock(&ar->mutex);
+                if (err)
+                        return err;
+        }
 
-        survey->channel = ar->channel;
+        for (b = 0; b < IEEE80211_NUM_BANDS; b++) {
+                band = ar->hw->wiphy->bands[b];
+
+                if (!band)
+                        continue;
+
+                for (i = 0; i < band->n_channels; i++) {
+                        if (band->channels[i].hw_value == idx) {
+                                chan = &band->channels[i];
+                                goto found;
+                        }
+                }
+        }
+        return -ENOENT;
+
+found:
+        memcpy(survey, &ar->survey[idx], sizeof(*survey));
+
+        survey->channel = chan;
         survey->filled = SURVEY_INFO_NOISE_DBM;
-        survey->noise = ar->noise[0];
+
+        if (ar->channel == chan)
+                survey->filled |= SURVEY_INFO_IN_USE;
+
+        if (ar->fw.hw_counters) {
+                survey->filled |= SURVEY_INFO_CHANNEL_TIME |
+                                  SURVEY_INFO_CHANNEL_TIME_BUSY |
+                                  SURVEY_INFO_CHANNEL_TIME_TX;
+        }
+
         return 0;
 }
 
@@ -1569,6 +1650,7 @@ void *carl9170_alloc(size_t priv_size)
         INIT_WORK(&ar->ping_work, carl9170_ping_work);
         INIT_WORK(&ar->restart_work, carl9170_restart_work);
         INIT_WORK(&ar->ampdu_work, carl9170_ampdu_work);
+        INIT_DELAYED_WORK(&ar->stat_work, carl9170_stat_work);
         INIT_DELAYED_WORK(&ar->tx_janitor, carl9170_tx_janitor);
         INIT_LIST_HEAD(&ar->tx_ampdu_list);
         rcu_assign_pointer(ar->tx_ampdu_iter,
@@ -1652,6 +1734,7 @@ static int carl9170_parse_eeprom(struct ar9170 *ar)
         struct ath_regulatory *regulatory = &ar->common.regulatory;
         unsigned int rx_streams, tx_streams, tx_params = 0;
         int bands = 0;
+        int chans = 0;
 
         if (ar->eeprom.length == cpu_to_le16(0xffff))
                 return -ENODATA;
@@ -1675,14 +1758,24 @@ static int carl9170_parse_eeprom(struct ar9170 *ar)
         if (ar->eeprom.operating_flags & AR9170_OPFLAG_2GHZ) {
                 ar->hw->wiphy->bands[IEEE80211_BAND_2GHZ] =
                         &carl9170_band_2GHz;
+                chans += carl9170_band_2GHz.n_channels;
                 bands++;
         }
         if (ar->eeprom.operating_flags & AR9170_OPFLAG_5GHZ) {
                 ar->hw->wiphy->bands[IEEE80211_BAND_5GHZ] =
                         &carl9170_band_5GHz;
+                chans += carl9170_band_5GHz.n_channels;
                 bands++;
         }
 
+        if (!bands)
+                return -EINVAL;
+
+        ar->survey = kzalloc(sizeof(struct survey_info) * chans, GFP_KERNEL);
+        if (!ar->survey)
+                return -ENOMEM;
+        ar->num_channels = chans;
+
         /*
          * I measured this, a bandswitch takes roughly
          * 135 ms and a frequency switch about 80.
@@ -1701,7 +1794,7 @@ static int carl9170_parse_eeprom(struct ar9170 *ar)
         /* second part of wiphy init */
         SET_IEEE80211_PERM_ADDR(ar->hw, ar->eeprom.mac_address);
 
-        return bands ? 0 : -EINVAL;
+        return 0;
 }
 
 static int carl9170_reg_notifier(struct wiphy *wiphy,
@@ -1834,6 +1927,9 @@ void carl9170_free(struct ar9170 *ar)
         kfree(ar->mem_bitmap);
         ar->mem_bitmap = NULL;
 
+        kfree(ar->survey);
+        ar->survey = NULL;
+
         mutex_destroy(&ar->mutex);
 
         ieee80211_free_hw(ar->hw);
diff --git a/drivers/net/wireless/ath/carl9170/phy.c b/drivers/net/wireless/ath/carl9170/phy.c
index 8635c5c8463c..472efc7e3402 100644
--- a/drivers/net/wireless/ath/carl9170/phy.c
+++ b/drivers/net/wireless/ath/carl9170/phy.c
@@ -1573,6 +1573,9 @@ int carl9170_get_noisefloor(struct ar9170 *ar)
                         AR9170_PHY_EXT_CCA_MIN_PWR, phy_res[i + 2]), 8);
         }
 
+        if (ar->channel)
+                ar->survey[ar->channel->hw_value].noise = ar->noise[0];
+
         return 0;
 }
 
@@ -1765,10 +1768,6 @@ int carl9170_set_channel(struct ar9170 *ar, struct ieee80211_channel *channel,
                 ar->chan_fail = 0;
         }
 
-        err = carl9170_get_noisefloor(ar);
-        if (err)
-                return err;
-
         if (ar->heavy_clip) {
                 err = carl9170_write_reg(ar, AR9170_PHY_REG_HEAVY_CLIP_ENABLE,
                                          0x200 | ar->heavy_clip);