firewire: core: fill model field in modalias of unit device for legacy layout of configuration ROM

As the last part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when
constructing modalias for unit device. The change brings loss of backward
compatibility since it can fill model field ('mo') which is 0 at current
implementation in the case. However, we can be optimistic against
regression for unit drivers in kernel, due to some points:

1. ALSA drivers for audio and music units use the model fields to match
device, however all of supported devices does not have such legacy
layout.
2. the other unit drivers (e.g. sbp2) does not use the model field to
match device.

The rest of concern is user space application. The most of applications
just take care of node device and does not use the modalias of unit
device, thus the change does not affect to them. But systemd project is
known to get affects from the change since it includes hwdb to take udev
to configure fw character device conveniently. I have a plan to work for
systemd so that the access permission of character device could be kept
across the change.

Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-9-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: detect model name for legacy layout of configuration ROM

As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model_name'
attribute appears in node device, however it is probable to see the other
types of descriptor leaf if the vendor directory includes.

Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-8-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: detect numeric model identifier for legacy layout of configuration ROM

As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model' attribute
appears in node device, however it is probable to see the other types of
immediate values if the vendor directory includes.

Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: test: add test of device attributes for legacy AV/C device

Some legacy devices have configuration ROM against standard AV/C device.
They have vendor directory to store model identifier. It is described in
annex of the following document.

- Configuration ROM for AV/C Devices 1.0 (Dec. 12, 2000, 1394 Trading
Association)

In the case, current implementation of core function does not detect the
model identifier, thus device attributes and modalias of unit have lack of
it. Another KUnit test is required for the case, and this commit is for
the purpose.

The following output is the parse result for the hard-coded data, by
config-rom-pretty-printer in linux-firewire-utils
(https://git.kernel.org/pub/scm/utils/ieee1394/linux-firewire-utils.git/).
The data is written by my hand.

$ config-rom-pretty-printer < /tmp/rom.img
ROM header and bus information block
-----------------------------------------------------------------
1024 04199fe7 bus_info_length 4, crc_length 25, crc 40935
1028 31333934 bus_name "1394"
1032 e0644000 irmc 1, cmc 1, isc 1, bmc 0, cyc_clk_acc 100, max_rec 4 (32)
1036 00112233 company_id 001122 |
1040 44556677 device_id 220189779575 | EUI-64 4822678189205111

root directory
-----------------------------------------------------------------
1044 0005dace directory_length 5, crc 56014
1048 03012345 vendor
1052 0c0083c0 node capabilities: per IEEE 1394
1056 8d000009 --> eui-64 leaf at 1092
1060 d1000002 --> unit directory at 1068
1064 c3000004 --> vendor directory at 1080

unit directory at 1068
-----------------------------------------------------------------
1068 0002e107 directory_length 2, crc 57607
1072 12abcdef specifier id
1076 13543210 version

vendor directory at 1080
-----------------------------------------------------------------
1080 0002cb73 directory_length 2, crc 52083
1084 17fedcba model
1088 81000004 --> descriptor leaf at 1104

eui-64 leaf at 1092
-----------------------------------------------------------------
1092 00026dc1 leaf_length 2, crc 28097
1096 00112233 company_id 001122 |
1100 44556677 device_id 220189779575 | EUI-64 4822678189205111

descriptor leaf at 1104
-----------------------------------------------------------------
1104 00050e84 leaf_length 5, crc 3716
1108 00000000 textual descriptor
1112 00000000 minimal ASCII
1116 41424344 "ABCD"
1120 45464748 "EFGH"
1124 494a0000 "IJ"

Link: https://lore.kernel.org/r/20231221134849.603857-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: test: add test of device attributes for simple AV/C device

At present, core function can handle node which has configuration ROM
similar to standard AV/C device somehow. The standard layout of
configuration ROM is described in the following document.

- Configuration ROM for AV/C Devices 1.0 (Dec. 12, 2000, 1394 Trading
Association)

This commit adds a KUnit test for the above case.

The following output is the parse result for the hard-coded data, by
config-rom-pretty-printer in linux-firewire-utils
(https://git.kernel.org/pub/scm/utils/ieee1394/linux-firewire-utils.git/).

$ config-rom-pretty-printer < /tmp/rom.img
ROM header and bus information block
-----------------------------------------------------------------
1024 0404eabf bus_info_length 4, crc_length 4, crc 60095
1028 31333934 bus_name "1394"
1032 e0646102 irmc 1, cmc 1, isc 1, bmc 0, cyc_clk_acc 100, max_rec 6 (128)
1036 ffffffff company_id ffffff |
1040 ffffffff device_id 1099511627775 | EUI-64 18446744073709551615

root directory
-----------------------------------------------------------------
1044 00063287 directory_length 6, crc 12935
1048 03ffffff vendor
1052 8100000a --> descriptor leaf at 1092
1056 17ffffff model
1060 8100000e --> descriptor leaf at 1116
1064 0c0083c0 node capabilities: per IEEE 1394
1068 d1000001 --> unit directory at 1072

unit directory at 1072
-----------------------------------------------------------------
1072 0004442d directory_length 4, crc 17453
1076 1200a02d specifier id
1080 13010001 version
1084 17ffffff model
1088 81000007 --> descriptor leaf at 1116

descriptor leaf at 1092
-----------------------------------------------------------------
1092 0005c915 leaf_length 5, crc 51477
1096 00000000 textual descriptor
1100 00000000 minimal ASCII
1104 56656e64 "Vend"
1108 6f72204e "or N"
1112 616d6500 "ame"

descriptor leaf at 1116
-----------------------------------------------------------------
1116 00057f16 leaf_length 5, crc 32534
1120 00000000 textual descriptor
1124 00000000 minimal ASCII
1128 4d6f6465 "Mode"
1132 6c204e61 "l Na"
1136 6d650000 "me"

Link: https://lore.kernel.org/r/20231221134849.603857-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: test: add KUnit test for device attributes

The traverse over CSR space results in attributes of node and unit
devices. Any test of the traverse is useful.

This commit adds a skeleton of KUnit test for the purpose.

Link: https://lore.kernel.org/r/20231221134849.603857-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>