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  1. 12 Apr, 2023 4 commits
    • Richard Fitzgerald's avatar
      ASoC: cs35l56: Add basic system suspend handling · f9dc6b87
      Richard Fitzgerald authored 
      This adds the main handling for system suspend but does not handle
re-patching the firmware after system resume.

This is a multi-stage suspend and resume because if there is a
RESET line it is almost certain that it will be shared by all the
amps. So every amp must have done its suspend before we can
assert RESET. Likewise we must de-assert RESET before the amps
can resume.

It's preferable to assert RESET before we turning off regulators, and
while they power up.

The actual suspend and resume is done by using the pair
pm_runtime_force_suspend() and pm_runtime_force_resume() to
re-use our runtime suspend/resume sequences.

pm_runtime_force_suspend() will disable our pm_runtime. If we were
runtime-resumed it calls our runtime_suspend().

pm_runtime_force_resume() re-enables pm_runtime and if we were
originally runtime-resumed before the pm_runtime_force_suspend()
it calls our runtime_resume(). Otherwise it leaves us
runtime-suspended.

The general process is therefore:

 suspend() -> finish dsp_work and then run our runtime_suspend
 suspend_late() -> assert RESET and turn off supplies
 resume_early() -> enable supplies and de-assert RESET
 resume() -> pm_runtime_force_resume()

In addition, to prevent the IRQ handler running in the period
between pm_runtime_force_suspend() and pm_runtime_force_resume()
the parent IRQ is temporarily disabled:
 - from suspend until suspend_noirq
 - from resume_noirq until resume
Signed-off-by: default avatarRichard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230411152528.329803-6-rf@opensource.cirrus.comSigned-off-by: default avatarMark Brown <broonie@kernel.org>
      f9dc6b87
    • Richard Fitzgerald's avatar
      ASoC: cs35l56: Always wait for firmware boot in runtime-resume · f00abadd
      Richard Fitzgerald authored 
      When we are resuming from a system suspend the CS35L56 has probably
been hard reset (usually a power-on reset). So we must wait for the
firmware to boot. On SoundWire we also need it to re-initialize before
we can read the registers to check the CS35L56 state.

The simplest way to handle this is for runtime-resume to always wait
for firmware boot. If the firmware is already booted the overhead is
only one register read.

The system-resume will have to runtime-resume the driver anyway before
attempting any register access. So this will automatically include the
wait for initialization on SoundWire.
Signed-off-by: default avatarRichard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230411152528.329803-5-rf@opensource.cirrus.comSigned-off-by: default avatarMark Brown <broonie@kernel.org>
      f00abadd
    • Richard Fitzgerald's avatar
      ASoC: cs35l56: Skip first init_completion wait in dsp_work if init_done · 7816e340
      Richard Fitzgerald authored 
      At the start of dsp_work() only wait for init_completion if !init_done.
This allows system suspend to re-queue dsp_work() without having to
do a dummy complete() of init_completion.

A dummy completion in system suspend would have to be conditional on
init_done. But that would create a possible race condition between our
system resume and cs35l56_init() in the corner case that we suspend right
after the SoundWire core has enumerated and reported ATTACHED.

It is safer and simpler to have cs35l56_init() as the only place that
init_completion is completed, and dsp_work() as the only place that
it is consumed.
Signed-off-by: default avatarRichard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230411152528.329803-4-rf@opensource.cirrus.comSigned-off-by: default avatarMark Brown <broonie@kernel.org>
      7816e340
    • Richard Fitzgerald's avatar
      ASoC: cs35l56: Use DAPM widget for firmware PLAY/PAUSE · 7b98a1ef
      Richard Fitzgerald authored 
      If we use a DAPM widget instead of mute_stream() to send the
PLAY command we can issue the plays to multiple amps in parallel.
With mute_stream each codec driver instance is called one at a
time so we get N * PS0 delay time.

DAPM does each stage on every widget in a card before moving to
the next stage. So all amps will do the PRE_PMU then all will do
the POST_PMU. The PLAY is sent in the PRE_PMU so that they all
power-up in parallel. After the PS0 wait in the first POST_PMU
all the other amps will also be ready so there won't be any extra
delay, or it will be negligible.

There's also no point waiting for the MBOX ack in the PRE_PMU.
We won't see a PS0 state in POST_PMU if it didn't ack the PLAY
command. So we can save a little extra time.
Signed-off-by: default avatarRichard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230411152528.329803-3-rf@opensource.cirrus.comSigned-off-by: default avatarMark Brown <broonie@kernel.org>
      7b98a1ef
  3. 11 Apr, 2023 10 commits
  5. 07 Apr, 2023 2 commits
  7. 06 Apr, 2023 24 commits
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