[alsa-devel] [PATCH] ALSA: ASoC: add codec driver for TI TAS5086

[jonsmirl at gmail.com]

On Wed, May 22, 2013 at 2:25 PM, Daniel Mack <zonque at gmail.com> wrote:
> On 22.05.2013 20:01, jonsmirl at gmail.com wrote:
>> On Wed, May 22, 2013 at 1:55 PM, Daniel Mack <zonque at gmail.com> wrote:
>>> On 22.05.2013 19:50, jonsmirl at gmail.com wrote:
>>>> On Fri, Mar 8, 2013 at 6:07 AM, Daniel Mack <zonque at gmail.com> wrote:
>>>>> This patch adds a driver for TI's TA5086 6-channel PWM processor.
>>>>>
>>>>> This chip has a very unusual register layout, specifically because the
>>>>> registers are of unequal size, and multi-byte registers require bulk
>>>>> writes to take effect. Regmap does not support these kind of mappings.
>>>>>
>>>>> Currently, the driver does not touch any of the registers >= 0x20, so
>>>>> it doesn't matter, because the register map is mapped to an 8-bit array.
>>>>> In case more features will be added in the future that require access
>>>>> to higher registers, the entire regmap H/W I/O routines have to be
>>>>> open-coded.
>>>>
>>>> Check out my tas5504 driver from a long time ago. It dealt with those registers.
>>>>
>>>> https://github.com/jonsmirl/mpc5200/blob/master/sound/soc/codecs/tas5504.c
>>>> https://github.com/jonsmirl/mpc5200/blob/master/sound/soc/codecs/tas5504.h
>>>
>>> Sure, without any regmap abstractions, things are somehow manageable.
>>> Though you lose all the nice things that regmap gives you, such as
>>> hardware independence and caching. I might have a different solution,
>>> but I need to get my hands on one of these devices to test.
>>>
>>> On a slightly different note: why isn't your driver in the mainline kernel?
>>
>> TI doesn't make the chip any more.
>
> That might be, but we have tons of drivers for devices in the mainline
> kernel which aren't in production anymore.

Yes, but they were added before the chips went out of production.

Mark/Liam - you can add my TAS5504 driver if you want it. As far as I
know there is no Linux based hardware using the chip except for a few
prototypes we built about five years ago.

Of course it is easier to find CPU boards with exposed I2S (we had to
build a CPU board too) now than it was five years ago so these chips
may see more activity. Those TI evals board should easily attach to a
Beaglebone.

>
>
> Daniel
>



--
Jon Smirl
jonsmirl at gmail.com