2010-07-28 05:13:01

by rd bairva

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Subject: JPEG hw decoder

Hi ,
My board has a hardware JPEG decoder. I want to write a driver
for this in Linux kernel, But it seems there that no Framework exists
in kernel. Can somebody provide me some pointers?

Thanks in advance.


Regards,
Rbairva


2010-07-28 08:13:13

by Baurzhan Ismagulov

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Subject: Re: JPEG hw decoder

On Wed, Jul 28, 2010 at 10:42:53AM +0530, rd bairva wrote:
> My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

http://lwn.net/Kernel/LDD3/

You'd probably want to define the application interface using open /
read / write / ioctl / poll / close and implement them in a character
device.

With kind regards,
Baurzhan.

2010-07-28 08:15:24

by Viresh Kumar

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Subject: Re: JPEG hw decoder

On 7/28/2010 10:42 AM, rd bairva wrote:
> Hi ,
> My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

Hello Rbairva,

Which JPEG decoder are you working on??

I have Synopsys JPEG Decoder/Encoder on ST SPEAr platform
and i am currently working on its driver for LKML.

I already have a driver for it which is not aligned to LKML guidelines,
and so doing modifications there.
In my driver i have used char device framework and none other suits it well.

viresh.

2010-07-28 09:04:43

by Eric Miao

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Subject: Re: JPEG hw decoder

On Wed, Jul 28, 2010 at 4:15 PM, viresh kumar <[email protected]> wrote:
> On 7/28/2010 10:42 AM, rd bairva wrote:
>> Hi ,
>>       My board has a hardware JPEG decoder. I want to write a driver
>> for this in Linux kernel, But it seems there that no Framework exists
>> in kernel. Can somebody provide me some pointers?
>
> Hello Rbairva,
>
> Which JPEG decoder are you working on??
>
> I have Synopsys JPEG Decoder/Encoder on ST SPEAr platform
> and i am currently working on its driver for LKML.
>
> I already have a driver for it which is not aligned to LKML guidelines,
> and so doing modifications there.
> In my driver i have used char device framework and none other suits it well.
>

Normally the JPEG decoder/encoder comes with the video camera
module, which falls in v4l2 framework. Though not sure how well
the v4l2 API is gonna support this.

> viresh.
>
> _______________________________________________
> linux-arm-kernel mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

2010-07-28 09:38:03

by Pawel Moll

[permalink] [raw]
Subject: Re: JPEG hw decoder

Hi,

> My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

If I was to do the same, I'd look around V4L2 API. If covers things like
video encoders/decoders etc. The only problem is that the particular
area you are interested in is not well defined yet:

http://linuxtv.org/downloads/v4l-dvb-apis/ch04s05.html

This means that people usually extend the API in their own way, staying
within the framework itself, obviously.

Maybe you could ask about this on the linux-media mailing list?

http://vger.kernel.org/vger-lists.html#linux-media

Good luck!

Paweł

2010-07-28 19:12:39

by Guennadi Liakhovetski

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Subject: Re: JPEG hw decoder

On Wed, 28 Jul 2010, rd bairva wrote:

> Hi ,
> My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

drivers/media/video, maybe v4l2-mem2mem kind of thing.

Regards
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/