On Wed, 30 Nov 2022 15:33:13 +0100, Takashi Sakamoto wrote:
TC Applied Technologies (TCAT) produces TCD3070 as final DICE ASIC for communication in IEEE 1394 bus for IEC 61883-1/6 protocol. As long as I know, latter model of Focusrite Saffire Pro 40 is an application of the ASIC and only in the market for consumers.
This patchset adds support for the device. The device has several remarkable points.
- No support for extended synchronization information section in TCAT
general protocol. The value of GLOBAL_EXTENDED_STATUS register is always zero. Additionally, NOTIFY_EXT_STATUS message is never emitted.
- No support for TCAT protocol extension. Hard coding is required for
format of CIP payload.
- During several seconds after changing sampling rate, the block to
process PCM frames is under disfunction. When starting packet streaming during the state, the block is never function till configuring different sampling rate and several seconds.
This commit adds support for the device. The item 1 and 2 can be adaptable, while item 3 is not. It's not preferable that user process is forced to sleep during the disfunction in the call of ioctl(2) with SNDRV_PCM_IOCTL_HW_PARAMS or SNDRV_PCM_IOCTL_PREPARE request. It's inconvenient but let user configure preferable sampling rate in advance of starting PCM substream.
The content of configuration ROM in the device I used is available at:
I note that any mixer control operation is implemented by unique transaction. The frame of request consists of 16 bytes header followed by payload.
header (4 quadlets): 1st: the type of request, prefixed with 0x8000 2nd: counter at 2 bytes in MSB side, the length of data at 2 bytes in LSB side 3rd: parameter 0 4th: parameter 1
payload (variable length if need): 5th-: data according to parameters
The request frame is sent by block write request to 0x'ffff'e040'01c0.
The frame of response is similar to the frame of request, but it is header only, thus fixed to 16 bytes. The response frame is sent to the address which is registered by lock transaction to 0x'ffff'e040'0008.
If the operation results in batch of data, the 2nd quadlet of header includes the length of data like request. The data is itself readable by read block request to 0x'ffff'e040'0030, which includes both header and payload for data, thus the length to read should be the length of data plus 16 bytes for header
The actual value of request, parameter 0, parameter 1, and data is unclear yet.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp
Thanks, applied.
Takashi