From: Sanyog Kale sanyog.r.kale@intel.com
Add example and documentation to describe multi link streams
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Signed-off-by: Sanyog Kale sanyog.r.kale@intel.com Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Shreyas NC shreyas.nc@intel.com --- Documentation/driver-api/soundwire/stream.rst | 29 ++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/Documentation/driver-api/soundwire/stream.rst b/Documentation/driver-api/soundwire/stream.rst index 29121aa..11623aab 100644 --- a/Documentation/driver-api/soundwire/stream.rst +++ b/Documentation/driver-api/soundwire/stream.rst @@ -75,7 +75,6 @@ Slaves are using single port. :: | (Data) | +---------------+
- Example 4: Stereo Stream with L and R channel is rendered by two different Ports of the Master and is received by only single Port of the Slave interface. :: @@ -101,6 +100,34 @@ 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 ================================