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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-23 15:19:00 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-23 15:19:00 +0300 |
commit | 33e12f6e4552b3377ef9076029442282d782eb9e (patch) | |
tree | c635c40760ac0ffbe92e2fc16a7ce1dde37a0229 /Documentation/driver-api | |
parent | baca54d956f77be9abc487bcdddf7a2a1fbbda1b (diff) | |
parent | 39ec6f992131f0e88910700286d83f5f48f4ee8f (diff) | |
download | linux-33e12f6e4552b3377ef9076029442282d782eb9e.tar.xz |
Merge tag 'soundwire-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire into char-misc-next
Vinod writes:
soundwire updates for v5.7-rc1
This contains updates to stream and pm handling in the core as well as
updates to Intel drivers for hw sequencing and multi-link.
Details:
Core:
- Updates to stream handling for state machine checks
- Changes to handle potential races for probe/enumeration and init of the bus
- Add no pm version of read and writes
- Support for multiple Slave on same link
- Add read_only_wordlength for simple/reduced ports
Intel:
- Updates to cadence lib to handle hw sequencing
- Support for audio dai calls in intel driver
- Multi link support for cadence lib
Qualcomm:
- Support for get_sdw_stream()
* tag 'soundwire-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire: (43 commits)
soundwire: qcom: add support for get_sdw_stream()
soundwire: stream: Add read_only_wordlength flag to port properties
soundwire: cadence: clear FIFO to avoid pop noise issue on playback start
soundwire: cadence: multi-link support
soundwire: cadence: commit changes in the exit_reset() sequence
soundwire: cadence: remove automatic command retries
soundwire: cadence: remove PREQ_DELAY assignment
soundwire: cadence: enable NORMAL operation in cdns_init()
soundwire: cadence: reorder MCP_CONFIG settings
soundwire: cadence: make SSP interval programmable
soundwire: cadence: move clock/SSP related inits to dedicated function
soundwire: cadence: merge routines to clear/set bits
soundwire: cadence: mask Slave interrupt before stopping clock
soundwire: cadence: fix a io timeout issue in S3 test
soundwire: cadence: add clock_stop/restart routines
soundwire: cadence: handle error cases with CONFIG_UPDATE
soundwire: cadence: add interface to check clock status
soundwire: cadence: simplifiy cdns_init()
soundwire: cadence: s/update_config/config_update
soundwire: stream: use sdw_write instead of update
...
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r-- | Documentation/driver-api/soundwire/stream.rst | 61 |
1 files changed, 44 insertions, 17 deletions
diff --git a/Documentation/driver-api/soundwire/stream.rst b/Documentation/driver-api/soundwire/stream.rst index 5351bd2f34a8..8bceece51554 100644 --- a/Documentation/driver-api/soundwire/stream.rst +++ b/Documentation/driver-api/soundwire/stream.rst @@ -156,22 +156,27 @@ Below shows the SoundWire stream states and state transition diagram. :: +-----------+ +------------+ +----------+ +----------+ | ALLOCATED +---->| CONFIGURED +---->| PREPARED +---->| ENABLED | | STATE | | STATE | | STATE | | STATE | - +-----------+ +------------+ +----------+ +----+-----+ - ^ - | - | - v - +----------+ +------------+ +----+-----+ + +-----------+ +------------+ +---+--+---+ +----+-----+ + ^ ^ ^ + | | | + __| |___________ | + | | | + v | v + +----------+ +-----+------+ +-+--+-----+ | RELEASED |<----------+ DEPREPARED |<-------+ DISABLED | | STATE | | STATE | | STATE | +----------+ +------------+ +----------+ -NOTE: State transition between prepare and deprepare is supported in Spec -but not in the software (subsystem) +NOTE: State transitions between ``SDW_STREAM_ENABLED`` and +``SDW_STREAM_DISABLED`` are only relevant when then INFO_PAUSE flag is +supported at the ALSA/ASoC level. Likewise the transition between +``SDW_DISABLED_STATE`` and ``SDW_PREPARED_STATE`` depends on the +INFO_RESUME flag. -NOTE2: Stream state transition checks need to be handled by caller -framework, for example ALSA/ASoC. No checks for stream transition exist in -SoundWire subsystem. +NOTE2: The framework implements basic state transition checks, but +does not e.g. check if a transition from DISABLED to ENABLED is valid +on a specific platform. Such tests need to be added at the ALSA/ASoC +level. Stream State Operations ----------------------- @@ -246,6 +251,9 @@ SDW_STREAM_PREPARED Prepare state of stream. Operations performed before entering in this state: + (0) Steps 1 and 2 are omitted in the case of a resume operation, + where the bus bandwidth is known. + (1) Bus parameters such as bandwidth, frame shape, clock frequency, are computed based on current stream as well as already active stream(s) on Bus. Re-computation is required to accommodate current @@ -270,9 +278,11 @@ Prepare state of stream. Operations performed before entering in this state: After all above operations are successful, stream state is set to ``SDW_STREAM_PREPARED``. -Bus implements below API for PREPARE state which needs to be called once per -stream. From ASoC DPCM framework, this stream state is linked to -.prepare() operation. +Bus implements below API for PREPARE state which needs to be called +once per stream. From ASoC DPCM framework, this stream state is linked +to .prepare() operation. Since the .trigger() operations may not +follow the .prepare(), a direct transition from +``SDW_STREAM_PREPARED`` to ``SDW_STREAM_DEPREPARED`` is allowed. .. code-block:: c @@ -332,6 +342,14 @@ Bus implements below API for DISABLED state which needs to be called once per stream. From ASoC DPCM framework, this stream state is linked to .trigger() stop operation. +When the INFO_PAUSE flag is supported, a direct transition to +``SDW_STREAM_ENABLED`` is allowed. + +For resume operations where ASoC will use the .prepare() callback, the +stream can transition from ``SDW_STREAM_DISABLED`` to +``SDW_STREAM_PREPARED``, with all required settings restored but +without updating the bandwidth and bit allocation. + .. code-block:: c int sdw_disable_stream(struct sdw_stream_runtime * stream); @@ -353,9 +371,18 @@ state: After all above operations are successful, stream state is set to ``SDW_STREAM_DEPREPARED``. -Bus implements below API for DEPREPARED state which needs to be called once -per stream. From ASoC DPCM framework, this stream state is linked to -.trigger() stop operation. +Bus implements below API for DEPREPARED state which needs to be called +once per stream. ALSA/ASoC do not have a concept of 'deprepare', and +the mapping from this stream state to ALSA/ASoC operation may be +implementation specific. + +When the INFO_PAUSE flag is supported, the stream state is linked to +the .hw_free() operation - the stream is not deprepared on a +TRIGGER_STOP. + +Other implementations may transition to the ``SDW_STREAM_DEPREPARED`` +state on TRIGGER_STOP, should they require a transition through the +``SDW_STREAM_PREPARED`` state. .. code-block:: c |