From 8cf3f9cfd9dc9e448012576b9a06cce2d294e400 Mon Sep 17 00:00:00 2001 From: Sanyog Kale Date: Fri, 27 Jul 2018 14:44:11 +0530 Subject: Documentation: soundwire: Add documentation for multi link Add example and documentation to describe multi link streams Signed-off-by: Pierre-Louis Bossart Signed-off-by: Sanyog Kale Signed-off-by: Shreyas NC Acked-by: Pierre-Louis Bossart Signed-off-by: Vinod Koul --- Documentation/driver-api/soundwire/stream.rst | 28 +++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'Documentation/driver-api/soundwire') diff --git a/Documentation/driver-api/soundwire/stream.rst b/Documentation/driver-api/soundwire/stream.rst index 29121aa55fb9..19482eedc3bf 100644 --- a/Documentation/driver-api/soundwire/stream.rst +++ b/Documentation/driver-api/soundwire/stream.rst @@ -101,6 +101,34 @@ interface. :: +--------------------+ | | +----------------+ +Example 5: Stereo Stream with L and R channel is rendered by 2 Masters, each +rendering one channel, and is received by two different Slaves, each +receiving one channel. Both Masters and both Slaves are using single port. :: + + +---------------+ Clock Signal +---------------+ + | Master +----------------------------------+ Slave | + | Interface | | Interface | + | 1 | | 1 | + | | Data Signal | | + | L +----------------------------------+ L | + | (Data) | Data Direction | (Data) | + +---------------+ +-----------------------> +---------------+ + + +---------------+ Clock Signal +---------------+ + | Master +----------------------------------+ Slave | + | Interface | | Interface | + | 2 | | 2 | + | | Data Signal | | + | R +----------------------------------+ R | + | (Data) | Data Direction | (Data) | + +---------------+ +-----------------------> +---------------+ + +Note: In multi-link cases like above, to lock, one would acquire a global +lock and then go on locking bus instances. But, in this case the caller +framework(ASoC DPCM) guarantees that stream operations on a card are +always serialized. So, there is no race condition and hence no need for +global lock. + SoundWire Stream Management flow ================================ -- cgit v1.2.1