firewire: implement broadcast_channel CSR for 1394a compliance

See IEEE 1394a clause 8.3.2.3.11.

Signed-off-by: Stefan Richter <[e-mail]>

drivers/firewire/fw-card.c

···
 	card->current_tlabel = 0;
 	card->tlabel_mask = 0;
 	card->color = 0;
+	card->broadcast_channel = BROADCAST_CHANNEL_INITIAL;
 
 	INIT_LIST_HEAD(&card->transaction_list);
 	spin_lock_init(&card->lock);

drivers/firewire/fw-transaction.c

···
 	int reg = offset & ~CSR_REGISTER_BASE;
 	unsigned long long bus_time;
 	__be32 *data = payload;
+	int rcode = RCODE_COMPLETE;
 
 	switch (reg) {
 	case CSR_CYCLE_TIME:
 	case CSR_BUS_TIME:
 		if (!TCODE_IS_READ_REQUEST(tcode) || length != 4) {
-			fw_send_response(card, request, RCODE_TYPE_ERROR);
+			rcode = RCODE_TYPE_ERROR;
 			break;
 		}
 
···
 			*data = cpu_to_be32(bus_time);
 		else
 			*data = cpu_to_be32(bus_time >> 25);
-		fw_send_response(card, request, RCODE_COMPLETE);
+		break;
+
+	case CSR_BROADCAST_CHANNEL:
+		if (tcode == TCODE_READ_QUADLET_REQUEST)
+			*data = cpu_to_be32(card->broadcast_channel);
+		else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
+			card->broadcast_channel =
+			    (be32_to_cpu(*data) & BROADCAST_CHANNEL_VALID) |
+			    BROADCAST_CHANNEL_INITIAL;
+		else
+			rcode = RCODE_TYPE_ERROR;
 		break;
 
 	case CSR_BUS_MANAGER_ID:
···
 
 	case CSR_BUSY_TIMEOUT:
 		/* FIXME: Implement this. */
+
 	default:
-		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
+		rcode = RCODE_ADDRESS_ERROR;
 		break;
 	}
+
+	fw_send_response(card, request, rcode);
 }
 
 static struct fw_address_handler registers = {

drivers/firewire/fw-transaction.h

···
 #define CSR_SPEED_MAP			0x2000
 #define CSR_SPEED_MAP_END		0x3000
 
+#define BROADCAST_CHANNEL_INITIAL	(1 << 31 | 31)
+#define BROADCAST_CHANNEL_VALID		(1 << 30)
+
 #define fw_notify(s, args...) printk(KERN_NOTICE KBUILD_MODNAME ": " s, ## args)
 #define fw_error(s, args...) printk(KERN_ERR KBUILD_MODNAME ": " s, ## args)
 
···
 	 */
 	int self_id_count;
 	u32 topology_map[252 + 3];
+	u32 broadcast_channel;
 
 	spinlock_t lock; /* Take this lock when handling the lists in
 			  * this struct. */