Re: [PATCH 0/5] ASoC: ti: davinci-mcasp: Fix the DIT mode and OMAP4 support

["Péter Ujfalusi" <peter.ujfalusi@gmail.com>]

Hi Nikolaus,

On 05/07/2021 16:32, H. Nikolaus Schaller wrote:
> Hi Péter,
> 
>> Am 04.07.2021 um 17:04 schrieb Peter Ujfalusi <peter.ujfalusi@gmail.com>:
>>
>> Hi,
>>
>> it has been on my todo list for several years to support McASP on OMAP4 devices.
>> For Galaxy Nexus we had an omap-mcasp driver (which was mostly a stripped down
>> davinci-mcasp driver) to support what was needed on that specific phone + it's
>> dock for S/PDIF (48KHz, 16bit, stereo).
>>
>> Not many (if any) device available to test the DIT mode of McASP.
>> I have used BeagleBone White (McASP1 AXR3 can be routed to a pin) to get the
>> S/PDIF mode working then PandaES for OMAP4 support (on PandaES the gpio_121 is
>> not used and the signal is routed to expansion J6 pin14)
>>
>> In theory the McASP in OMAP5 should be working after this series, but the OMAP5
>> TRM is not public and I do not have one to check the addresses and see if there
>> is a way to test it on omap5-uevm.
>>
>> Mark, Tony:
>> The ASoC and dts patches can go via separate tree I felt that it is better if
>> they are together, at least initially.
>>
>> Nikolaus: fyi, this might be useful for Pyra?
> 
> Yes, definitively.
> 
> I just wonder how compatible it is with the "old" omap-mcasp driver we carry
> along for the Pyra:
> 
> https://git.goldelico.com/?p=letux-kernel.git;a=blob;f=sound/soc/ti/omap-mcasp.c;h=24d839a24f34ec02456176744d3690016592b5a3;hb=7789ab635e56a2fd9fe04ca2e9ccfeaccb8e0f52
> 
> Does it now have additional functionality or robustness?

The davinci-mcasp with series does work on OMAP4. I could not made the
omap-mcasp working. I have picked the driver from pyra in hopes that it
is working so I will ahve a stable base.
Have you tested it?

the omap-mcasp supports only 48KHz and 16bit, no passthrough, no 24bit,
all is hardwired for the Galaxy Nexus setup, afaik.

The davinci-mcasp should be better all around, I think the PM side is
also more robust.

The other point is that I would not accept the omap-mcasp driver
upstream. The IP is the same so the driver should be also...

> And does it need changes of the OMAP5 device tree?

In a similar way as the dts patches in this series.
fwiw:
https://github.com/omap-audio/linux-audio/commit/2f0a632db0b52321f1fc3623d088a741aeb72ef7
is the patch I have for PandaES to get S/PDIF working.

> And also important seems to be the ABE/AESS integration where we so far failed
> to make it work again on more recent kernels.

The McASP is not routed via ABE/AESS, it has been always handled outside
of the firmware, so it is just a simple link outside.

> Our most recent patch set is here:
> 
> https://git.goldelico.com/?p=letux-kernel.git;a=shortlog;h=refs/heads/letux/aess-v5

Yes, I'm following it ;)

> Anyways I am happy to see a little progress on the omap4/5 audio subsystem.

It is in maintenance mode as there is not much of an interest outside of
a small group of people, but I try to help to get it better for Pyra.

> BR and thanks,
> Nikolaus
> 
> 
> 
>>
>> Regards,
>> Péter
>> ---
>> Peter Ujfalusi (5):
>>  ASoC: ti: davinci-mcasp: Fix DIT mode support
>>  ASoC: dt-bindings: davinci-mcasp: Add compatible string for OMAP4
>>  ASoC: ti: davinci-mcasp: Add support for the OMAP4 version of McASP
>>  ARM: dts: omap4-l4-abe: Correct sidle modes for McASP
>>  ARM: dts: omap4-l4-abe: Add McASP configuration
>>
>> .../bindings/sound/davinci-mcasp-audio.txt    |   1 +
>> arch/arm/boot/dts/omap4-l4-abe.dtsi           |  39 ++--
>> include/linux/platform_data/davinci_asp.h     |   1 +
>> sound/soc/ti/Kconfig                          |   1 +
>> sound/soc/ti/davinci-mcasp.c                  | 168 +++++++++++++++---
>> 5 files changed, 168 insertions(+), 42 deletions(-)
>>
>> -- 
>> 2.32.0
>>
> 

-- 
Péter