p54: control output power levels

I hope this patch is enough to cover at least the basic requirements of IEEE 802.11h's TPC.
Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/p54/p54.h

@@ -88,6 +88,7 @@ struct p54_common {
 	void *cached_vdcf;
 	unsigned int fw_var;
 	unsigned int fw_interface;
+	unsigned int output_power;
 	u32 tsf_low32;
 	u32 tsf_high32;
 	struct ieee80211_tx_queue_stats tx_stats[8];

drivers/net/wireless/p54/p54common.c

@@ -800,7 +800,7 @@ static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 	txhdr->hw_queue = skb_get_queue_mapping(skb) + 4;
 	txhdr->tx_antenna = (info->antenna_sel_tx == 0) ?
 		2 : info->antenna_sel_tx - 1;
-	txhdr->output_power = 0x7f; // HW Maximum
+	txhdr->output_power = priv->output_power;
 	txhdr->cts_rate = (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 			  0 : cts_rate;
 	if (padding)
@@ -1154,6 +1154,7 @@ static int p54_config(struct ieee80211_hw *dev, struct ieee80211_conf *conf)
 	mutex_lock(&priv->conf_mutex);
 	priv->rx_antenna = (conf->antenna_sel_rx == 0) ?
 		2 : conf->antenna_sel_tx - 1;
+	priv->output_power = conf->power_level << 2;
 	ret = p54_set_freq(dev, cpu_to_le16(conf->channel->center_freq));
 	p54_set_vdcf(dev);
 	mutex_unlock(&priv->conf_mutex);