iwlagn: implement layout-agnostic EEPROM reading

The current EEPROM reading code has some layout
assumptions that now turned out to be false with
some newer versions of the EEPROM. Luckily, we
can avoid all such assumptions by using data in
the EEPROM itself, so implement using that.

However, for risk mitigation purposes, keep the
old reading code for current hardware for now.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

1 files changed, 84 insertions, 1 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-eeprom.c b/drivers/net/wireless/iwlwifi/iwl-agn-eeprom.c
index 7c1be8c..cf9194b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-eeprom.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-eeprom.c
@@ -433,7 +433,7 @@ static s8 iwl_update_channel_txpower(struct iwl_priv *priv,
 /**
  * iwlcore_eeprom_enhanced_txpower: process enhanced tx power info
  */
-void iwlcore_eeprom_enhanced_txpower(struct iwl_priv *priv)
+static void iwlcore_eeprom_enhanced_txpower_old(struct iwl_priv *priv)
 {
 	int eeprom_section_count = 0;
 	int section, element;
@@ -494,3 +494,86 @@ void iwlcore_eeprom_enhanced_txpower(struct iwl_priv *priv)
 		}
 	}
 }
+
+static void
+iwlcore_eeprom_enh_txp_read_element(struct iwl_priv *priv,
+				    struct iwl_eeprom_enhanced_txpwr *txp,
+				    s8 max_txpower_avg)
+{
+	int ch_idx;
+	bool is_ht40 = txp->flags & IWL_EEPROM_ENH_TXP_FL_40MHZ;
+	enum ieee80211_band band;
+
+	band = txp->flags & IWL_EEPROM_ENH_TXP_FL_BAND_52G ?
+		IEEE80211_BAND_5GHZ : IEEE80211_BAND_2GHZ;
+
+	for (ch_idx = 0; ch_idx < priv->channel_count; ch_idx++) {
+		struct iwl_channel_info *ch_info = &priv->channel_info[ch_idx];
+
+		/* update matching channel or from common data only */
+		if (txp->channel != 0 && ch_info->channel != txp->channel)
+			continue;
+
+		/* update matching band only */
+		if (band != ch_info->band)
+			continue;
+
+		if (ch_info->max_power_avg < max_txpower_avg && !is_ht40) {
+			ch_info->max_power_avg = max_txpower_avg;
+			ch_info->curr_txpow = max_txpower_avg;
+			ch_info->scan_power = max_txpower_avg;
+		}
+
+		if (is_ht40 && ch_info->ht40_max_power_avg < max_txpower_avg)
+			ch_info->ht40_max_power_avg = max_txpower_avg;
+	}
+}
+
+#define EEPROM_TXP_OFFS	(0x00 | INDIRECT_ADDRESS | INDIRECT_TXP_LIMIT)
+#define EEPROM_TXP_ENTRY_LEN sizeof(struct iwl_eeprom_enhanced_txpwr)
+#define EEPROM_TXP_SZ_OFFS (0x00 | INDIRECT_ADDRESS | INDIRECT_TXP_LIMIT_SIZE)
+
+static void iwlcore_eeprom_enhanced_txpower_new(struct iwl_priv *priv)
+{
+	struct iwl_eeprom_enhanced_txpwr *txp_array, *txp;
+	int idx, entries;
+	__le16 *txp_len;
+	s8 max_txp_avg, max_txp_avg_halfdbm;
+
+	BUILD_BUG_ON(sizeof(struct iwl_eeprom_enhanced_txpwr) != 8);
+
+	/* the length is in 16-bit words, but we want entries */
+	txp_len = (__le16 *) iwlagn_eeprom_query_addr(priv, EEPROM_TXP_SZ_OFFS);
+	entries = le16_to_cpup(txp_len) * 2 / EEPROM_TXP_ENTRY_LEN;
+
+	txp_array = (void *) iwlagn_eeprom_query_addr(priv, EEPROM_TXP_OFFS);
+	for (idx = 0; idx < entries; idx++) {
+		txp = &txp_array[idx];
+
+		/* skip invalid entries */
+		if (!(txp->flags & IWL_EEPROM_ENH_TXP_FL_VALID))
+			continue;
+
+		max_txp_avg = iwl_get_max_txpower_avg(priv, txp_array, idx,
+						      &max_txp_avg_halfdbm);
+
+		/*
+		 * Update the user limit values values to the highest
+		 * power supported by any channel
+		 */
+		if (max_txp_avg > priv->tx_power_user_lmt)
+			priv->tx_power_user_lmt = max_txp_avg;
+		if (max_txp_avg_halfdbm > priv->tx_power_lmt_in_half_dbm)
+			priv->tx_power_lmt_in_half_dbm = max_txp_avg_halfdbm;
+
+		iwlcore_eeprom_enh_txp_read_element(priv, txp, max_txp_avg);
+	}
+}
+
+void iwlcore_eeprom_enhanced_txpower(struct iwl_priv *priv)
+{
+	if (priv->cfg->use_new_eeprom_reading)
+		iwlcore_eeprom_enhanced_txpower_new(priv);
+	else
+		iwlcore_eeprom_enhanced_txpower_old(priv);
+}