wl1271: Update TX packet life time handling with higher resolution time

This patch uses a higher precision timer to synchronize with the firmware
clock. Improved precision is needed as on some platforms a jiffy may be up to
tens of milliseconds, and the required precision is closer to TU's.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/wl12xx/wl1271.h

@@ -404,7 +404,7 @@ struct wl1271 {
 	u32 tx_packets_count;
 
 	/* Time-offset between host and chipset clocks */
-	int time_offset;
+	s64 time_offset;
 
 	/* Session counter for the chipset */
 	int session_counter;

drivers/net/wireless/wl12xx/wl1271_main.c

@@ -374,6 +374,7 @@ static void wl1271_power_on(struct wl1271 *wl)
 static void wl1271_fw_status(struct wl1271 *wl,
 			     struct wl1271_fw_status *status)
 {
+	struct timespec ts;
 	u32 total = 0;
 	int i;
 
@@ -402,8 +403,9 @@ static void wl1271_fw_status(struct wl1271 *wl,
 		ieee80211_queue_work(wl->hw, &wl->tx_work);
 
 	/* update the host-chipset time offset */
-	wl->time_offset = jiffies_to_usecs(jiffies) -
-		le32_to_cpu(status->fw_localtime);
+	getnstimeofday(&ts);
+	wl->time_offset = (timespec_to_ns(&ts) >> 10) -
+		(s64)le32_to_cpu(status->fw_localtime);
 }
 
 #define WL1271_IRQ_MAX_LOOPS 10

drivers/net/wireless/wl12xx/wl1271_tx.c

@@ -86,8 +86,10 @@ static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
 static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
 			      u32 extra, struct ieee80211_tx_info *control)
 {
+	struct timespec ts;
 	struct wl1271_tx_hw_descr *desc;
 	int pad, ac;
+	s64 hosttime;
 	u16 tx_attr;
 
 	desc = (struct wl1271_tx_hw_descr *) skb->data;
@@ -101,8 +103,9 @@ static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
 	}
 
 	/* configure packet life time */
-	desc->start_time = cpu_to_le32(jiffies_to_usecs(jiffies) -
-				       wl->time_offset);
+	getnstimeofday(&ts);
+	hosttime = (timespec_to_ns(&ts) >> 10);
+	desc->start_time = cpu_to_le32(hosttime - wl->time_offset);
 	desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU);
 
 	/* configure the tx attributes */