Hello,
I kept it as RFC as i reworked the global design (but also because not full validated...). Regarding Mark and Jonathan's comments, I decided to try an implementation with DMA support in IIO instead of handling it in ASOC. Solution seems more straightforward but as DMA cyclic mode and associated buffer block API is not part of IIO today, I still need some hacks... To be honest, I tried to integrate DMA cyclic management and associated buffer block Consumer API. but no enough expertise on IIO to success... :(
Advantage vs V2: - No more data processing need in ASoC , done in IIO - ASoC uses IIO consumer interface ( except for buffer callback) Drawback : - Need to create a "SPI bus" trigger to allo to use Buffer consumer API => Need to find a solution to set this trigger by default in IIO audio driver - No standard buffer management - Implement DMA cyclic in DFSDM IIO driver. - Define specific API to handle buffer callback per period instead of callback per samples generated by iio_push_to_buffers_with_timestamp.
V2-V3 delta: - New patches to support ASoC DMA codec in DT - ASoC: Add Bindins for DMIC codec driver. - ASoC: codec: add DT support in dmic codec. - New patches to allow in-kernel set of IIO buffer size and watermark - IIO: consumer: allow to set buffer sizes. - IIO DFSDM drivers - Split audio and ADC support in 2 drivers. - Implement DMA cyclic mode. - Add SPI bus Trigger for buffer management.
- IIO sigma delta adc drivers - Suppress "simple and rename driver.
- ASoC driver - Suppress DMA engine. - Suppress copy ops. - Use IIO consmumer interface to enable/Disable DFSDM.
Regards,
Arnaud
Arnaud Pouliquen (11): iio: Add hardware consumer support IIO: Add DT bindings for sigma delta adc modulator IIO: ADC: add sigma delta modulator support IIO: add DT bindings for stm32 DFSDM filter IIO: ADC: add stm32 DFSDM support for Sigma delta ADC IIO: ADC: add stm32 DFSDM support for PDM microphone IIO: consumer: allow to set buffer sizes ASoC: Add Bindins for DMIC codec driver ASoC: codec: add DT support in dmic codec ASoC: add bindings for stm32 DFSDM filter ASoC: stm32: add DFSDM DAI support
.../bindings/iio/adc/sigma-delta-modulator.txt | 13 + .../bindings/iio/adc/st,stm32-dfsdm-adc.txt | 120 ++++ Documentation/devicetree/bindings/sound/dmic.txt | 11 + .../devicetree/bindings/sound/st,stm32-adfsdm.txt | 41 ++ drivers/iio/Kconfig | 6 + drivers/iio/Makefile | 1 + drivers/iio/adc/Kconfig | 50 ++ drivers/iio/adc/Makefile | 4 + drivers/iio/adc/sd_adc_modulator.c | 98 +++ drivers/iio/adc/stm32-dfsdm-adc.c | 419 ++++++++++++ drivers/iio/adc/stm32-dfsdm-audio.c | 720 +++++++++++++++++++++ drivers/iio/adc/stm32-dfsdm-core.c | 658 +++++++++++++++++++ drivers/iio/adc/stm32-dfsdm.h | 372 +++++++++++ drivers/iio/buffer/industrialio-buffer-cb.c | 12 + drivers/iio/hw_consumer.c | 156 +++++ include/linux/iio/adc/stm32-dfsdm-audio.h | 41 ++ include/linux/iio/consumer.h | 13 + include/linux/iio/hw_consumer.h | 12 + sound/soc/Kconfig | 1 + sound/soc/Makefile | 1 + sound/soc/codecs/dmic.c | 8 + sound/soc/stm/Kconfig | 10 + sound/soc/stm/Makefile | 2 + sound/soc/stm/stm32_adfsdm.c | 362 +++++++++++ 24 files changed, 3131 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/sigma-delta-modulator.txt create mode 100644 Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.txt create mode 100644 Documentation/devicetree/bindings/sound/dmic.txt create mode 100644 Documentation/devicetree/bindings/sound/st,stm32-adfsdm.txt create mode 100644 drivers/iio/adc/sd_adc_modulator.c create mode 100644 drivers/iio/adc/stm32-dfsdm-adc.c create mode 100644 drivers/iio/adc/stm32-dfsdm-audio.c create mode 100644 drivers/iio/adc/stm32-dfsdm-core.c create mode 100644 drivers/iio/adc/stm32-dfsdm.h create mode 100644 drivers/iio/hw_consumer.c create mode 100644 include/linux/iio/adc/stm32-dfsdm-audio.h create mode 100644 include/linux/iio/hw_consumer.h create mode 100644 sound/soc/stm/Kconfig create mode 100644 sound/soc/stm/Makefile create mode 100644 sound/soc/stm/stm32_adfsdm.c
V2:
Patch-set associated to this RFC proposes an implementation of the DFSDM features shared between ASoC and IIO frameworks.
Patch-set is only a Skeleton of the drivers, so a base to discuss and validate a design. It contains minimum code to allow probing (with DT) and to expose the ASoC and IIO ABI. Hope that is sufficent in a first step to allow to focus on APIs.
In this patch-set there are two new APIs used: - IIO in-kern API: based on hw_customer API proposed by Lars - ASOC <-> IIO API inspired by API defined for hdmi-codec for ASoC/DRM interconnect. API is dedicated to DFSDM only.
Notice also that this design is based on following assumption: - Audio stream ABI interface is ASoC, no access to data through IIO ABI for PDM. - ASoC DMA should be used for audio transfer as designed for real time stream. - Need some runtime parameters exchange between ASoC and IIO due to the correlation between the sample frequency, the DFSDM decimation factor and the associated scaling.
- "ASoC: dmaengine_pcm: add copy support" patch: I added a patch in ASoC that allows to implement a copy function to process data after DMA transfer. Requested, as DFSDM samples captured contain channel ID on 8-LSB bits and need also a potential rescale to present DAT on 24-bits.
- "IIO: ADC: add sigma delta modulator support" patch: Simple dummy driver created to support external Sigma delta modulator. It is binded to DFSDM driver through hw_customer API.
- 1.9.1