From 0c4a1049cf298721eaec4553d3d5039798086e12 Mon Sep 17 00:00:00 2001 From: Sanyog Kale Date: Fri, 27 Jul 2018 14:44:13 +0530 Subject: soundwire: Add support to lock across bus instances Currently, the stream concept is limited to single Master and one or more Codecs. This patch extends the concept to support multiple Master(s) sharing the same reference clock and synchronized in the hardware. Modify sdw_stream_runtime to support a list of sdw_master_runtime for the same. The existing reference to a single m_rt is removed in the next patch. Typically to lock, one would acquire a global lock and then lock bus instances. 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. Bus lock(s) are acquired to reconfigure the bus while the stream is set-up. So, we add sdw_acquire_bus_lock()/sdw_release_bus_lock() APIs which are used only to reconfigure the bus. Signed-off-by: Sanyog Kale Signed-off-by: Shreyas NC Acked-by: Pierre-Louis Bossart Signed-off-by: Vinod Koul --- include/linux/soundwire/sdw.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/soundwire') diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index 962971e6a9c7..ccd8dcdf06ab 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -769,6 +769,9 @@ struct sdw_stream_params { * @state: Current state of the stream * @type: Stream type PCM or PDM * @m_rt: Master runtime + * @master_list: List of Master runtime(s) in this stream. + * master_list can contain only one m_rt per Master instance + * for a stream */ struct sdw_stream_runtime { char *name; @@ -776,6 +779,7 @@ struct sdw_stream_runtime { enum sdw_stream_state state; enum sdw_stream_type type; struct sdw_master_runtime *m_rt; + struct list_head master_list; }; struct sdw_stream_runtime *sdw_alloc_stream(char *stream_name); -- cgit v1.2.3-59-g8ed1b