[PATCH v5 0/4] ASoC: cdns: Add Cadence I2S-SC and I2S-MC controller support

[joakim.zhang@cixtech.com]

From: Joakim Zhang <joakim.zhang@cixtech.com>

This series adds support for the Cadence I2S-SC and I2S-MC controllers
integrated in the CIX SKY1 audio subsystem, together with their DT
bindings.

I2S-SC provides full-duplex stereo playback and capture in standard
I2S, left/right-justified and DSP modes, along with TDM operation
supporting up to 16 slots. I2S-MC provides multi-channel playback and
capture through a configurable set of its 8 data pins, described by
cix,pin-out-num, cix,pin-rx-mask and cix,pin-tx-mask, and exposes a
transmit DAI and a receive DAI.

Both drivers register the dmaengine PCM helper, select the audio
reference clock parent for the 8 kHz or 11.025 kHz sample rate family
and keep the minimum functional-clock to bit-clock ratio required for
safe clock domain crossing.

The two binding patches are unchanged since v4 and keep Rob's
Reviewed-by tags.

Changes in v5:
- I2S-MC: fix the DSP_A/DSP_B mapping in set_fmt(). The DATA_WS_DEL bit
  was assigned to the wrong format: per the controller implementation
  specification, data aligned with the word-select strobe (DSP_B) is
  DATA_WS_DEL set, and data delayed by one bit clock after the strobe
  (DSP_A) is DATA_WS_DEL clear. Swap the assignment for both the
  transmitter and the receiver.
- I2S-MC: return -EBUSY from hw_params() when the sample-rate family of
  the new stream needs a different i2s clock parent than the one already
  in use, since the transmit and receive DAIs share the clk_i2s parent
  mux; the parent is compared with clk_is_match().
- I2S-SC: let set_tdm_slot() switch TDM mode off when called with zero
  slots, which is how machine drivers return a DAI to standard I2S
  operation, while still rejecting negative slot counts.
- Both: rework the probe and teardown runtime PM handling. Enable
  runtime PM only after the IRQ is requested, unwind the clocks and the
  runtime PM state through a single error path, and gate the clocks in
  the new remove() callback when the device is still runtime-active;
  this also covers module removal with CONFIG_PM=n, where nothing else
  would disable the clocks.

Changes in v4:
- Enforce the dma-names order in the bindings: a single "tx" or "rx"
  name is still allowed for single-direction instances, but a pair must
  be "tx", "rx".
- Drop the DMA controller stub node from the binding examples.
- Select REGMAP_MMIO; a COMPILE_TEST build without it would fail to
  link the regmap MMIO users.
- Include the transmitter and receiver synchronizing-unit reset bits in
  the masked register write of the I2S-MC DAI probe, so that the write
  actually programs the state its comment describes.

Changes in v3:
- Add the explicit <linux/bitfield.h> include, which a W=1 build of the
  FIELD_PREP() sites needs (both drivers).
- Fix the probe error paths: disable the manually enabled clocks and
  drop the runtime PM usage count on every failure path, unwinding
  through a single goto label (both drivers).
- Return dev_err_probe() directly instead of logging with it and then
  returning the error separately (both drivers).

Changes in v2:
- Move the IRQ request after the clocks are enabled and the reset is
  released, so the handler never runs against unclocked hardware.
- Disable the IRQ before switching the regcache to cache-only mode on
  suspend, and re-enable it only after the cache is synced on resume;
  check the status read in the ISR (both drivers).
- Replace the manual runtime PM bookkeeping with devm_pm_runtime_enable()
  and drop the remove() callbacks (both drivers).
- Switch to RUNTIME_PM_OPS()/SYSTEM_SLEEP_PM_OPS() wrapped in pm_ptr()
  and drop the __maybe_unused annotations (both drivers).
- Serialize the shared transceiver clock state in prepare() against the
  trigger() state machine with the existing spinlock (I2S-SC).
- Disable clocks in the reverse order of enablement (both drivers).
- Sort the cdns/ entry into the vendor list in sound/soc/Makefile and
  switch sound/soc/cdns/Makefile to the '-y' object syntax.
- Clean up the includes and initializer style (both drivers).
- Add a NULL check for the match data in probe (both drivers).
- Factor the MC transmitter and receiver configuration into a shared
  helper.
- Drop the compatible string from the DMAC stub node in the binding
  examples.

Signed-off-by: Joakim Zhang <joakim.zhang@cixtech.com>

Joakim Zhang (4):
  ASoC: dt-bindings: Add Cadence I2S-SC controller
  ASoC: cdns: Add Cadence I2S-SC controller driver
  ASoC: dt-bindings: Add Cadence I2S-MC controller
  ASoC: cdns: Add Cadence I2S-MC controller driver

 .../bindings/sound/cix,sky1-i2s-mc.yaml       |  119 ++
 .../bindings/sound/cix,sky1-i2s-sc.yaml       |   89 ++
 sound/soc/Kconfig                             |    1 +
 sound/soc/Makefile                            |    1 +
 sound/soc/cdns/Kconfig                        |   23 +
 sound/soc/cdns/Makefile                       |    7 +
 sound/soc/cdns/cdns-i2s-mc.c                  | 1152 ++++++++++++++++
 sound/soc/cdns/cdns-i2s-sc.c                  | 1171 +++++++++++++++++
 8 files changed, 2563 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/cix,sky1-i2s-mc.yaml
 create mode 100644 Documentation/devicetree/bindings/sound/cix,sky1-i2s-sc.yaml
 create mode 100644 sound/soc/cdns/Kconfig
 create mode 100644 sound/soc/cdns/Makefile
 create mode 100644 sound/soc/cdns/cdns-i2s-mc.c
 create mode 100644 sound/soc/cdns/cdns-i2s-sc.c

-- 
2.50.1