mwl8k: Adding support to gather survey per channel

Survey stats such as channel busy time, rx busy time
and noise are collected when sw_scan starts for every
switched new channel. This happens till sw_scan stops.

All the collected stats are shared up when get_survey()
is called.

This implements support for ACS feature from Hostapd.

Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: Nishant Sarmukadam <nishants@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 109 insertions, 6 deletions

diff --git a/drivers/net/wireless/mwl8k.c b/drivers/net/wireless/mwl8k.c
index 61d5bea9a9d7..b6d83f6888fa 100644
--- a/drivers/net/wireless/mwl8k.c
+++ b/drivers/net/wireless/mwl8k.c
@@ -115,6 +115,8 @@ MODULE_PARM_DESC(ap_mode_default,
  */
 #define MWL8K_NUM_AMPDU_STREAMS (TOTAL_HW_TX_QUEUES - 1)
 
+#define MWL8K_NUM_CHANS 18
+
 struct rxd_ops {
         int rxd_size;
         void (*rxd_init)(void *rxd, dma_addr_t next_dma_addr);
@@ -295,6 +297,9 @@ struct mwl8k_priv {
 
         /* ACS related */
         bool sw_scan_start;
+        struct ieee80211_channel *acs_chan;
+        unsigned long channel_time;
+        struct survey_info survey[MWL8K_NUM_CHANS];
 };
 
 #define MAX_WEP_KEY_LEN         13
@@ -3064,6 +3069,64 @@ mwl8k_cmd_set_post_scan(struct ieee80211_hw *hw, const __u8 *mac)
         return rc;
 }
 
+static int freq_to_idx(struct mwl8k_priv *priv, int freq)
+{
+        struct ieee80211_supported_band *sband;
+        int band, ch, idx = 0;
+
+        for (band = IEEE80211_BAND_2GHZ; band < IEEE80211_NUM_BANDS; band++) {
+                sband = priv->hw->wiphy->bands[band];
+                if (!sband)
+                        continue;
+
+                for (ch = 0; ch < sband->n_channels; ch++, idx++)
+                        if (sband->channels[ch].center_freq == freq)
+                                goto exit;
+        }
+
+exit:
+        return idx;
+}
+
+void mwl8k_update_survey(struct mwl8k_priv *priv,
+                         struct ieee80211_channel *channel)
+{
+        u32 cca_cnt, rx_rdy;
+        s8 nf = 0, idx;
+        struct survey_info *survey;
+
+        idx = freq_to_idx(priv, priv->acs_chan->center_freq);
+        if (idx >= MWL8K_NUM_CHANS) {
+                wiphy_err(priv->hw->wiphy, "Failed to update survey\n");
+                return;
+        }
+
+        survey = &priv->survey[idx];
+
+        cca_cnt = le32_to_cpu(ioread32(priv->regs + NOK_CCA_CNT_REG));
+        cca_cnt /= 1000; /* uSecs to mSecs */
+        survey->channel_time_busy = (u64) cca_cnt;
+
+        rx_rdy = le32_to_cpu(ioread32(priv->regs + BBU_RXRDY_CNT_REG));
+        rx_rdy /= 1000; /* uSecs to mSecs */
+        survey->channel_time_rx = (u64) rx_rdy;
+
+        priv->channel_time = jiffies - priv->channel_time;
+        survey->channel_time = jiffies_to_msecs(priv->channel_time);
+
+        survey->channel = channel;
+
+        mwl8k_cmd_bbp_reg_access(priv->hw, 0, BBU_AVG_NOISE_VAL, &nf);
+
+        /* Make sure sign is negative else ACS  at hostapd fails */
+        survey->noise = nf * -1;
+
+        survey->filled = SURVEY_INFO_NOISE_DBM |
+                         SURVEY_INFO_CHANNEL_TIME |
+                         SURVEY_INFO_CHANNEL_TIME_BUSY |
+                         SURVEY_INFO_CHANNEL_TIME_RX;
+}
+
 /*
  * CMD_SET_RF_CHANNEL.
  */
@@ -3081,6 +3144,7 @@ static int mwl8k_cmd_set_rf_channel(struct ieee80211_hw *hw,
         enum nl80211_channel_type channel_type =
                 cfg80211_get_chandef_type(&conf->chandef);
         struct mwl8k_cmd_set_rf_channel *cmd;
+        struct mwl8k_priv *priv = hw->priv;
         int rc;
 
         cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
@@ -3097,13 +3161,29 @@ static int mwl8k_cmd_set_rf_channel(struct ieee80211_hw *hw,
         else if (channel->band == IEEE80211_BAND_5GHZ)
                 cmd->channel_flags |= cpu_to_le32(0x00000004);
 
-        if (channel_type == NL80211_CHAN_NO_HT ||
-            channel_type == NL80211_CHAN_HT20)
+        if (!priv->sw_scan_start) {
+                if (channel_type == NL80211_CHAN_NO_HT ||
+                    channel_type == NL80211_CHAN_HT20)
+                        cmd->channel_flags |= cpu_to_le32(0x00000080);
+                else if (channel_type == NL80211_CHAN_HT40MINUS)
+                        cmd->channel_flags |= cpu_to_le32(0x000001900);
+                else if (channel_type == NL80211_CHAN_HT40PLUS)
+                        cmd->channel_flags |= cpu_to_le32(0x000000900);
+        } else {
                 cmd->channel_flags |= cpu_to_le32(0x00000080);
-        else if (channel_type == NL80211_CHAN_HT40MINUS)
-                cmd->channel_flags |= cpu_to_le32(0x000001900);
-        else if (channel_type == NL80211_CHAN_HT40PLUS)
-                cmd->channel_flags |= cpu_to_le32(0x000000900);
+        }
+
+        if (priv->sw_scan_start) {
+                /* Store current channel stats
+                 * before switching to newer one.
+                 * This will be processed only for AP fw.
+                 */
+                if (priv->channel_time != 0)
+                        mwl8k_update_survey(priv, priv->acs_chan);
+
+                priv->channel_time = jiffies;
+                priv->acs_chan =  channel;
+        }
 
         rc = mwl8k_post_cmd(hw, &cmd->header);
         kfree(cmd);
@@ -5311,6 +5391,27 @@ static int mwl8k_get_survey(struct ieee80211_hw *hw, int idx,
 {
         struct mwl8k_priv *priv = hw->priv;
         struct ieee80211_conf *conf = &hw->conf;
+        struct ieee80211_supported_band *sband;
+
+        if (priv->ap_fw) {
+                sband = hw->wiphy->bands[IEEE80211_BAND_2GHZ];
+
+                if (sband && idx >= sband->n_channels) {
+                        idx -= sband->n_channels;
+                        sband = NULL;
+                }
+
+                if (!sband)
+                        sband = hw->wiphy->bands[IEEE80211_BAND_5GHZ];
+
+                if (!sband || idx >= sband->n_channels)
+                        return -ENOENT;
+
+                memcpy(survey, &priv->survey[idx], sizeof(*survey));
+                survey->channel = &sband->channels[idx];
+
+                return 0;
+        }
 
         if (idx != 0)
                 return -ENOENT;
@@ -5463,6 +5564,7 @@ static void mwl8k_sw_scan_start(struct ieee80211_hw *hw)
                 return;
 
         /* clear all stats */
+        priv->channel_time = 0;
         ioread32(priv->regs + BBU_RXRDY_CNT_REG);
         ioread32(priv->regs + NOK_CCA_CNT_REG);
         mwl8k_cmd_bbp_reg_access(priv->hw, 0, BBU_AVG_NOISE_VAL, &tmp);
@@ -5481,6 +5583,7 @@ static void mwl8k_sw_scan_complete(struct ieee80211_hw *hw)
         priv->sw_scan_start = false;
 
         /* clear all stats */
+        priv->channel_time = 0;
         ioread32(priv->regs + BBU_RXRDY_CNT_REG);
         ioread32(priv->regs + NOK_CCA_CNT_REG);
         mwl8k_cmd_bbp_reg_access(priv->hw, 0, BBU_AVG_NOISE_VAL, &tmp);