On Tue, 24 Jan 2017, Arnaud Pouliquen wrote: > > > On 01/24/2017 12:36 PM, Lee Jones wrote: > > On Tue, 24 Jan 2017, Arnaud Pouliquen wrote: > >> On 01/24/2017 09:22 AM, Lee Jones wrote: > >>> On Mon, 23 Jan 2017, Arnaud Pouliquen wrote: > >>> > >>>> DFSDM hardware IP can be used at the same time for ADC sigma delta > >>> > >>> Same time as what? > >> DFSDM is used for ADC acquisition (through IIO) but also PDM microphone > >> capture (through ASOC). > >>> > >>>> conversion and audio PDM microphone. > >>>> MFD driver is in charge of configuring IP registers and managing IP clocks. > >>>> For this it exports an API to handles filters and channels resources. > >>> > >>> This looks like an ADC driver? What is it that makes it an MFD? > >> Yes it a kind of ADC but that supports 2 features audio and iio. > >> So it has to support 2 features based on 2 separate Frameworks. > > > > I'm still unsure why it needs to live in MFD. > > > > By the looks of it, this driver needs to move into IIO and you need to > > call into it from ASoC. > > > > I think i introduce confusion by speaking about ADC for audio... > > 1) IIO handles sigma delta ADCs that can be used as example for motor > controls. the aim is to get value based on an application request or > using some triggers. > example: http://www.ti.com/lit/ds/symlink/ads1202.pdf > > 2) For audio part, we speak about Digital mems microphones that generate > PDM format stream. PDM is a continuous real time stream dedicated to > audio record and must be handled in ASOC ( codec Dmic part driver is > /sound/soc/codec/dmic.c). > DMIC example: > http://www.st.com/content/ccc/resource/technical/document/datasheet/47/bd/d2/13/8d/fd/48/26/DM00121815.pdf/files/DM00121815.pdf/jcr:content/translations/en.DM00121815.pdf > > Form my point of view it very strange to handle DMICs in IIO, as it is > not designed to support audio streams.it is two separate features that > are not compatible. > > Now, from software point of view > That would means that IIO declares ADCs that it can not expose, because > DMIC is not IIO standard. But IIO inkern API needs that device is > declared > So i should define a specific API in IIO for ASOC driver. Yes, this is what I think you should do. MFD is not a dumping ground for devices that do not fit anywhere else. > >>>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> > >>>> --- > >>>> drivers/mfd/Kconfig | 11 + > >>>> drivers/mfd/Makefile | 2 + > >>>> drivers/mfd/stm32-dfsdm-reg.h | 220 +++++++++ > >>>> drivers/mfd/stm32-dfsdm.c | 1044 +++++++++++++++++++++++++++++++++++++++ > >>>> include/linux/mfd/stm32-dfsdm.h | 324 ++++++++++++ > >>>> 5 files changed, 1601 insertions(+) > >>>> create mode 100644 drivers/mfd/stm32-dfsdm-reg.h > >>>> create mode 100644 drivers/mfd/stm32-dfsdm.c > >>>> create mode 100644 include/linux/mfd/stm32-dfsdm.h > >>>> > >>>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > >>>> index c6df644..4bb660b 100644 > >>>> --- a/drivers/mfd/Kconfig > >>>> +++ b/drivers/mfd/Kconfig > >>>> @@ -1607,6 +1607,17 @@ config MFD_STW481X > >>>> in various ST Microelectronics and ST-Ericsson embedded > >>>> Nomadik series. > >>>> > >>>> +config MFD_STM32_DFSDM > >>>> + tristate "ST Microelectronics STM32 DFSDM" > >>>> + depends on (ARCH_STM32 && OF) || COMPILE_TEST > >>>> + select MFD_CORE > >>>> + select REGMAP > >>>> + select REGMAP_MMIO > >>>> + help > >>>> + Select this option to enable the STM32 Digital Filter > >>>> + for Sigma Delta Modulators (DFSDM) driver used > >>>> + in various STM32 series. > >>>> + > >>>> menu "Multimedia Capabilities Port drivers" > >>>> depends on ARCH_SA1100 > >>> > >>> [...] > >>> > >> > >> Regards > >> Arnaud > > -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
