[alsa-devel] [PATCH 2/7] MFD: add STM32 DFSDM support

[Arnaud Pouliquen]

Hello Lee,

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.

> 
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
>> ---
>>  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