[alsa-devel] [PATCH] ALSA: firewire-motu: add support MOTU 8pre FireWire

[Takashi Iwai]

On Sun, 17 Mar 2019 08:50:24 +0100,
Takashi Sakamoto wrote:
> 
> This commit adds support for MOTU 8pre FireWire, which was shipped 2007
> and nowadays already discontinued. Userspace applications can transmit
> and receive PCM frames and MIDI messages for this model via ALSA PCM
> interface and RawMidi/Sequencer interfaces.
> 
> Like the other models of MOTU FireWire series, this model has many
> quirks in its CIP.
> 
> At first, data channels for two pairs of optical interfaces. At lower
> sampling transmission frequency, i.e. 44.1 and 48.0 kHz, one pair is
> available for ADAT data, thus 8 data chunks are transferred by CIP.
> At middle sampling transmission frequency, i.e.  88.2 and 96.0 kHz,
> two pairs are available to keep 8 chunks for ADAT data, thus CIP
> still includes 8 data chunks.
> 
> Apart from data chunks for optical interface, CIP includes fixed number
> of data chunks. In tx stream, two chunks for status message, eight
> chunks for samples from analog 1-8 input, two chunks for mix-return.
> In rx stream, two chunks for control message, two chunks for main 1-2
> output, two chunks for phone 1-2 output, two chunks for dummy 1-2.
> 
> CIP header in tx stream includes quirks for its dbs and dbc fields.
> The value of dbs field is fixed to 0x13, against its actual size.
> The value of dbc field is firstly updated to 0x07 from zero, then
> it's incremented continuously according to actual number of data h
> blocks.
> 
> Finally, the model has own bits to disable frame fetch.
> 
> This commit uses several options to absorb the above quirks.
> 
> $ python2 crpp < /sys/bus/firewire/devices/fw1/config_rom
>                ROM header and bus information block
>                -----------------------------------------------------------------
> 400  0410b57d  bus_info_length 4, crc_length 16, crc 46461
> 404  31333934  bus_name "1394"
> 408  20001000  irmc 0, cmc 0, isc 1, bmc 0, cyc_clk_acc 0, max_rec 1 (4)
> 40c  0001f200  company_id 0001f2     |
> 410  00083dfb  device_id 0000083dfb  | EUI-64 0001f20000083dfb
> 
>                root directory
>                -----------------------------------------------------------------
> 414  0004c65c  directory_length 4, crc 50780
> 418  030001f2  vendor
> 41c  0c0083c0  node capabilities per IEEE 1394
> 420  8d000006  --> eui-64 leaf at 438
> 424  d1000001  --> unit directory at 428
> 
>                unit directory at 428
>                -----------------------------------------------------------------
> 428  0003991c  directory_length 3, crc 39196
> 42c  120001f2  specifier id
> 430  1300000f  version
> 434  17103800  model
> 
>                eui-64 leaf at 438
>                -----------------------------------------------------------------
> 438  00022681  leaf_length 2, crc 9857
> 43c  0001f200  company_id 0001f2     |
> 440  00083dfb  device_id 0000083dfb  | EUI-64 0001f20000083dfb
> 
> Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>

Applied to for-next branch now.  Thanks.


Takashi