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path: root/sound/firewire/fireface/ff-stream.c
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2017-04-05ALSA: fireface: add hwdep interfaceTakashi Sakamoto
This commit adds hwdep interface so as the other drivers for audio and music units on IEEE 1394 have. This interface is designed for mixer/control applications. By using this interface, an application can get information about firewire node, can lock/unlock kernel streaming and can get notification at starting/stopping kernel streaming. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-04-05ALSA: fireface: add stream management functionalityTakashi Sakamoto
This commit adds management functionality for packet streaming. As long as investigating Fireface 400, there're three modes depending on sampling transmission frequency. The number of data channels in each data block is different depending on the mode. The set of available data channels for each mode might be different for each protocol and model. The length of registers for the number of isochronous channel is just three bits, therefore 0-7ch are available. When bus reset occurs on IEEE 1394 bus, the device discontinues to transmit packets. This commit aborts PCM substreams at bus reset handler. As I described in followed commits, The device manages its sampling clock independently of sampling transmission frequency against IEC 61883-6. Thus, it's a lower cost to change the sampling transmission frequency, while data fetch between streaming layer and DSP require larger buffer for resampling. As a result, device latency might tend to be larger than ASICs for IEC 61883-1/6 such as DM1000/DM1100/DM1500 (BeBoB), DiceII/TCD2210/TCD2220/TCD3070 and OXFW970/971. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>