[RFC wpan-next] atusb: add support for trac feature

[Alexander Aring <aahringo@redhat.com>]

This patch adds support for reading the trac register if atusb firmware
reports tx done. There is currently a feature to compare a sequence
number, if the payload is 1 it tells the driver only the sequence number
is available if it's two there is additional the trac status register as
payload.

Currently the atusb_in_good() function determines if it's a tx done or
rx done if according the payload length. This patch is doing the same
and assumes this behaviour.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---

Just an RFC, need another weekend to test it.

 drivers/net/ieee802154/atusb.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ieee802154/atusb.c b/drivers/net/ieee802154/atusb.c
index 2c338783893d..95a4a3cdc8a4 100644
--- a/drivers/net/ieee802154/atusb.c
+++ b/drivers/net/ieee802154/atusb.c
@@ -191,7 +191,7 @@ static void atusb_work_urbs(struct work_struct *work)
 
 /* ----- Asynchronous USB -------------------------------------------------- */
 
-static void atusb_tx_done(struct atusb *atusb, u8 seq)
+static void atusb_tx_done(struct atusb *atusb, u8 seq, int reason)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	u8 expect = atusb->tx_ack_seq;
@@ -199,7 +199,10 @@ static void atusb_tx_done(struct atusb *atusb, u8 seq)
 	dev_dbg(&usb_dev->dev, "%s (0x%02x/0x%02x)\n", __func__, seq, expect);
 	if (seq == expect) {
 		/* TODO check for ifs handling in firmware */
-		ieee802154_xmit_complete(atusb->hw, atusb->tx_skb, false);
+		if (reason == IEEE802154_SUCCESS)
+			ieee802154_xmit_complete(atusb->hw, atusb->tx_skb, false);
+		else
+			ieee802154_xmit_error(atusb->hw, atusb->tx_skb, reason);
 	} else {
 		/* TODO I experience this case when atusb has a tx complete
 		 * irq before probing, we should fix the firmware it's an
@@ -215,7 +218,8 @@ static void atusb_in_good(struct urb *urb)
 	struct usb_device *usb_dev = urb->dev;
 	struct sk_buff *skb = urb->context;
 	struct atusb *atusb = SKB_ATUSB(skb);
-	u8 len, lqi;
+	int result = IEEE802154_SUCCESS;
+	u8 len, lqi, trac;
 
 	if (!urb->actual_length) {
 		dev_dbg(&usb_dev->dev, "atusb_in: zero-sized URB ?\n");
@@ -224,8 +228,27 @@ static void atusb_in_good(struct urb *urb)
 
 	len = *skb->data;
 
-	if (urb->actual_length == 1) {
-		atusb_tx_done(atusb, len);
+	switch (urb->actual_length) {
+	case 2:
+		trac = TRAC_MASK(*(skb->data + 1));
+		switch (trac) {
+		case TRAC_SUCCESS:
+		case TRAC_SUCCESS_DATA_PENDING:
+			/* already IEEE802154_SUCCESS */
+			break;
+		case TRAC_CHANNEL_ACCESS_FAILURE:
+			result = IEEE802154_CHANNEL_ACCESS_FAILURE;
+			break;
+		case TRAC_NO_ACK:
+			result = IEEE802154_NO_ACK;
+			break;
+		default:
+			result = IEEE802154_SYSTEM_ERROR;
+		}
+
+		fallthrough;
+	case 1:
+		atusb_tx_done(atusb, len, result);
 		return;
 	}
 
-- 
2.31.1