firewire: core: clean up config ROM related defined constants

Clemens Ladisch pointed out that
  - BIB_IMC is not named like the field is called in the standard,
  - readers of the code may get worried about the magic 0x0c0083c0,
  - a CSR_NODE_CAPABILITIES key is there in the header but not put to
    good use.

So let's rename BIB_IMC, add a defined constant for Node_Capabilities
and a comment which reassures people that somebody thought about it and
they don't have to (or if they still do, tell them where they have to
look for confirmation), and prune our incomplete and arbitrary set of
defined constants of CSR key IDs.  And there is a nother magic number,
that of Bus_Information_Block.Bus_Name, to be defined and commented.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/core-card.c

@@ -63,7 +63,7 @@ static size_t config_rom_length = 1 + 4 + 1 + 1;
 #define BIB_CRC(v)		((v) <<  0)
 #define BIB_CRC_LENGTH(v)	((v) << 16)
 #define BIB_INFO_LENGTH(v)	((v) << 24)
-
+#define BIB_BUS_NAME		0x31333934 /* "1394" */
 #define BIB_LINK_SPEED(v)	((v) <<  0)
 #define BIB_GENERATION(v)	((v) <<  4)
 #define BIB_MAX_ROM(v)		((v) <<  8)
@@ -73,7 +73,8 @@ static size_t config_rom_length = 1 + 4 + 1 + 1;
 #define BIB_BMC			((1) << 28)
 #define BIB_ISC			((1) << 29)
 #define BIB_CMC			((1) << 30)
-#define BIB_IMC			((1) << 31)
+#define BIB_IRMC		((1) << 31)
+#define NODE_CAPABILITIES	0x0c0083c0 /* per IEEE 1394 clause 8.3.2.6.5.2 */
 
 static void generate_config_rom(struct fw_card *card, __be32 *config_rom)
 {
@@ -91,18 +92,18 @@ static void generate_config_rom(struct fw_card *card, __be32 *config_rom)
 
 	config_rom[0] = cpu_to_be32(
 		BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0));
-	config_rom[1] = cpu_to_be32(0x31333934);
+	config_rom[1] = cpu_to_be32(BIB_BUS_NAME);
 	config_rom[2] = cpu_to_be32(
 		BIB_LINK_SPEED(card->link_speed) |
 		BIB_GENERATION(card->config_rom_generation++ % 14 + 2) |
 		BIB_MAX_ROM(2) |
 		BIB_MAX_RECEIVE(card->max_receive) |
-		BIB_BMC | BIB_ISC | BIB_CMC | BIB_IMC);
+		BIB_BMC | BIB_ISC | BIB_CMC | BIB_IRMC);
 	config_rom[3] = cpu_to_be32(card->guid >> 32);
 	config_rom[4] = cpu_to_be32(card->guid);
 
 	/* Generate root directory. */
-	config_rom[6] = cpu_to_be32(0x0c0083c0); /* node capabilities */
+	config_rom[6] = cpu_to_be32(NODE_CAPABILITIES);
 	i = 7;
 	j = 7 + descriptor_count;
 

include/linux/firewire.h

@@ -55,13 +55,11 @@
 #define CSR_DESCRIPTOR		0x01
 #define CSR_VENDOR		0x03
 #define CSR_HARDWARE_VERSION	0x04
-#define CSR_NODE_CAPABILITIES	0x0c
 #define CSR_UNIT		0x11
 #define CSR_SPECIFIER_ID	0x12
 #define CSR_VERSION		0x13
 #define CSR_DEPENDENT_INFO	0x14
 #define CSR_MODEL		0x17
-#define CSR_INSTANCE		0x18
 #define CSR_DIRECTORY_ID	0x20
 
 struct fw_csr_iterator {