[alsa-devel] Reforming s3c2443 ac97 driver

[jassi brar]

On Fri, Jan 22, 2010 at 9:43 AM, SeungHyun Choi <sh428.choi at samsung.com> wrote:
>
> Dear. Jassi
>
> Thank you for all the information of AC97 reforming.
>
> I'm working for Android smart phone now as T/L with Samsung Handset division (S3C6410 --> Galaxy-spica, InstinctQ)
>
> Actually, we are using I2S interface and external codec chip  for audio because of various functions of audio like connecting BT or modem.. etc.
>
> Honestly  out of my mind about AC97 codec. But your works are look fine. I agree too.
thanks for agreeing.

>
> I've reformed i2c & pcm driver in linux 2.6.29 too since android doesn't have audio library and diffrent from other OS like WM or Linux
I keep updated(after backporting latest code from Mark's GIT) Samsung
linux-2.6.29/31 that you might want to try out.

> It was so difficult to handle buffer management between Platform and Kernel. (noise, distortion. ...)
>
> Next time, I'd like to share with you if there is a chance.
>
> Regards.
>
>
>
> ------- Original Message -------
> Sender : jassi brar<jassisinghbrar at gmail.com>
> Date : 2010-01-21 15:58 (GMT+09:00)
> Title : Re: [alsa-devel] Reforming s3c2443 ac97 driver
>
> On Fri, Jan 8, 2010 at 6:48 PM, Mark Brown
> <broonie at opensource.wolfsonmicro.com> wrote:
> > On 8 Jan 2010, at 05:28, JASWINDERSINGH BRAR <jassi.brar at samsung.com>
> > wrote:
> >
> >> Hi,
> >>     Right now the S3C2443's AC97_ver2.0 controller driver isn't
> >> flexible enough
> >> to handle newer SoCs.
> >>   In order to prepare ground for supporting 64xx and S5Pxxxx the
> >> extant driver
> >> needs to be reformed, and that is what i am planning to do next.
> >>
> >> I plan to do the following:-
> >> 1) User platform_driver structure to detect and manage AC97 controller
> >> platform devices.
> >> 2) Remove hardcoded parameters(DMA, IO address, IRQ etc) and pass via
> >> platform resources.
> >> 3) Initialize platform specific stuff by callback pointers to
> >> platform code(cfg_gpio)
> >>
> >> Objections, suggestions welcome.
> >
> > This sounds like a good approach - please go ahead.
> There has been a slight change though.
>
> Both parts(platform_device interface and ALSA AC97 interface)
> of s3c2443-ac97.c needed so much reforming that I found rewriting the
> driver again a better option.
> The new driver is called 's3c-ac97.c' ... hoping the AC97 controller
> doesn't change in SoCs released after you read this mail :)
>
> The s3c2443-ac97.c is used by SMDK2443 and LN2440SBC machines. My new
> driver is at least as good as old one for SMDK2443(both detect
> controller fine but none produce any sound..
> might be some h/w issue on the only board I have got).
> I have no access to LN2440SBC but there is no reason for it to
> complain.
> Besides, the new AC97 controller driver(plus a machine driver for
> SMDKs with WM9713 attached to AC97 port) has been tested on all
> SoCs that I could get my hands on(6410, C100, C110 and V210).
>
> Trying to avoid one outright rejected series of patches, I wanted to
> confirm if my approach is acceptable.
>
>
>
>
>
> ________________________________
>
>
>
> 최 승 현 책임
>
> 삼성전자주식회사
>
> Embedded S/W Center
>
> System LSI사업부
>
> 반도체총괄
>
>
>
> 031-209-8330
>
> sh428.choi at samsung.com
>
>
>
> ________________________________
>
>
>
>