[RFC PATCH 0/7] AC97 device/driver model revamp

Robert Jarzmik
2016-04-30T21:16:48Z

It all started in the pxa device-tree submission here :
https://lkml.org/lkml/2016/2/25/965
It will be maintained in :
git fetch https://github.com/rjarzmik/linux.git work/ac97

And now it transformed into this RFC, which would bring a ground for AC'97
devices closer to the linux device/driver model.

This is just an RFC to see if we understand each other Mark.

Amongst the driving ideas behind this RFC :
- use device/driver model for AC'97
device/driver binding is based on vendor_id{1,2}
- use auto-probe of the AC'97 bus to enumerate codecs and create devices
- be compatible with previous platform_data model for codecs
=> this enables a smooth transition, where a codec (here wm9713) can
be used either through platform_device or automatic discovery
- struct snd_ac97 is not used
This structure is really heavy, and doesn't represent an AC97 device, but
rather an AC'97 codec internals IIUC.
I think it's right place would be in include/sound/ac97/codec.h.
This is also a problem for regmap adherence, hence the
include/sound/ac97/compat.h.
- a new AC'97 bus Kconfig is created
This was done for a smooth transition ... let's see if it's a good idea.
- split the AC'97 into :
- the codec
- the digital controller
- the bus

Amongst the things that are not all touched yet :
- ac97_codec.c
The generic AC'97 codec in sound/pci/ac97/ac97_codec.c has really a lot
features, which are not at all PCI related. They could be transfered to
sound/ac97, without the pci specific field.
=> this deserves a deep ahead thinking, which I'll do if the current approach
is accepted by the communauty.

The most important patch is 2/7 "ALSA: ac97: add an ac97 bus". This is the main
evaluation point for the serie, the others are here so that I can test it all.

Well, this is a long term effort, which might need a complete rewrite according
to the comments it'll get. Let's expose it for comments and see how I can
progress with it.

Cheers.

--
Robert

Robert Jarzmik (7):
ALSA: ac97: split out the generic ac97 registers
ALSA: ac97: add an ac97 bus
ASoC: wm9713: add ac97 new bus support
ASoC: pxa: switch to new ac97 bus support
ARM: pxa: mioa701 remove wm9713 from platform devices
ASoC: mioa701_wm9713: convert to new ac97 bus
ASoC: add new ac97 bus support

arch/arm/mach-pxa/mioa701.c | 1 -
include/sound/ac97/codec.h | 98 ++++++++++++
include/sound/ac97/compat.h | 21 +++
include/sound/ac97/controller.h | 39 +++++
include/sound/ac97/regs.h | 262 +++++++++++++++++++++++++++++++
include/sound/ac97_codec.h | 239 +----------------------------
include/sound/pxa2xx-lib.h | 14 +-
sound/Kconfig | 7 +
sound/Makefile | 1 +
sound/ac97/Kconfig | 9 ++
sound/ac97/Makefile | 5 +
sound/ac97/ac97_core.h | 10 ++
sound/ac97/bus.c | 330 ++++++++++++++++++++++++++++++++++++++++
sound/ac97/codec.c | 15 ++
sound/ac97/snd_ac97_compat.c | 104 +++++++++++++
sound/arm/Kconfig | 1 -
sound/arm/pxa2xx-ac97-lib.c | 31 ++--
sound/soc/Kconfig | 4 +
sound/soc/codecs/wm9713.c | 62 +++++++-
sound/soc/pxa/Kconfig | 4 +-
sound/soc/pxa/mioa701_wm9713.c | 4 +-
sound/soc/pxa/pxa2xx-ac97.c | 12 +-
22 files changed, 1000 insertions(+), 273 deletions(-)
create mode 100644 include/sound/ac97/codec.h
create mode 100644 include/sound/ac97/compat.h
create mode 100644 include/sound/ac97/controller.h
create mode 100644 include/sound/ac97/regs.h
create mode 100644 sound/ac97/Kconfig
create mode 100644 sound/ac97/Makefile
create mode 100644 sound/ac97/ac97_core.h
create mode 100644 sound/ac97/bus.c
create mode 100644 sound/ac97/codec.c
create mode 100644 sound/ac97/snd_ac97_compat.c

--
2.1.4