Hi,
On Sat, Oct 15, 2022 at 06:33:28PM -0500, George Hilliard wrote:
This short series adds a configuration block for the Firestudio Mobile I just acquired. Very similar to the Firestudio, but a lower port count.
My understanding is that the Low, Medium, and High speeds refer to 48kHz, 96kHz, and 192kHz sample rates, of which only the first two are supported by this hardware line. Please correct me if this is not correct.
Thanks!
Thanks for the patches, while the device, FireStudio Mobile, is already supported by ALSA dice driver since it has an entry of moddevice table which matches your device:
``` { .match_flags = IEEE1394_MATCH_VERSION, .version = DICE_INTERFACE, }, ```
I think you have the other troubles except for device detection.
In general protocol defined by TC Applied Technologies (the company which designed DICE ASICs and firmwares), two fields of content of configuration ROM have pre-defined values.
One of the fields is version field of unit directory. The value is 0x000001 (=DICE_INTERFACE). In your case, the content of unit directory is below. We can see the value of version field is 0x000001.
``` unit directory at 430 --------------------------------------------------- 430 00048030 directory_length 4, crc 32816 434 12000a92 specifier id: Presonus Corporation 438 13000001 version 43c 17000011 model 440 8100000f --> descriptor leaf at 47c ```
Another is EUI-64 field in bus information block. the part of field is used for 8 bit `category ID` and the value is 0. In your case, the value is below. The way to parese the field, please refer to `check_dice_category` function in `sound/firewire/dice/dice.c`[1].
``` ROM header and bus information block --------------------------------------------------- 400 0404bc6a bus_info_length 4, crc_length 4, crc 48234 404 31333934 bus_name "1394" 408 e0008102 irmc 1, cmc 1, isc 1, bmc 0, cyc_clk_acc 0, max_rec 8 (512) 40c 000a9204 company_id 000a92 | Presonus Corporation 410 047da647 device_id 04047da647 | EUI-64 000a9204047da647 ```
For the content of configuration ROM itself, documentation by 1394 Trading Association (vendor association back in several years ago) will be a great help[2].
As a supplement, TCAT general protocol has no way to share available stream formats at all of supported sampling transfer frequencies. It allows software just to read available stream formats at current sampling transfer frequency, while TCAT protocol extension has the function. ALSA dice driver is programmed to try the extension to detect, then works at limitation mode at failure. The pre-defined table you coded is for the case that the extension is not supported by device, but your device supports the extension.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git/tree/sound/f... [2] https://web.archive.org/web/20210216003042/http://1394ta.org/wp-content/uplo...
Thanks
Takashi Sakamoto