linux-fbdev-devel

[Linux-fbdev-devel] 2.4 official API ?

[Ghozlane T. <gt...@pr...>]

Hi *

I just wanted to know if ther is an official doc/howto about the frame
buffer API for 2.4 kernel .

is "vfb" up to date, and a good sampleof what should be done ? or is it
skelettonfb ?

thanks in advance .

ghoz

Re: [Linux-fbdev-devel] 2.4 official API ?

[James S. <jsi...@tr...>]

> I just wanted to know if ther is an official doc/howto about the frame
> buffer API for 2.4 kernel .

It looks like to have to update FB-Driver-HOWTO. 

> is "vfb" up to date, and a good sampleof what should be done ? or is it
> skelettonfb ?

Both should be updated. I can send a patch which also I hope encourages
people to migrate to the new api. I like to thank Russell King for moving
over the arm fbdev drivers to the new api. It makes my life easier :->

Re: [Linux-fbdev-devel] 2.4 official API ?

[Ghozlane T. <gt...@pr...>]

----- Original Message -----
From: "James Simmons" <jsi...@tr...>
Subject: Re: [Linux-fbdev-devel] 2.4 official API ?


> It looks like to have to update FB-Driver-HOWTO.

yep .. may i suggest a chapter on the changes between 2.2. and 2.4 ,
and between 2.4 and the upcomming 2.5 API ?

> > is "vfb" up to date, and a good sample of what should be done ? or is it
> > skelettonfb ?
> Both should be updated. I can send a patch which also I hope encourages
> people to migrate to the new api. I like to thank Russell King for moving
> over the arm fbdev drivers to the new api. It makes my life easier :->

I'm for sure interested .

I'm trying to bet back to work on my fb driver (voodoo1 and now voodoo2
officialy almost supported) after letting it sleep for way too long .

I'm having a hard time trying to merge the cleanups/fixes added in
the ruby tree and keeping 2.2/2.4 compatibility ...

So the question is how do i support 2.2/2.4 *and* the upcomming 2.5 API
without maintainig 3 separate sources : i have to work on the internals of
the driver,
and i don't feel like updating 3 files every time ...

any suggestions ?
how do you guys cope with that ?

thanks,
ghoz

Re: [Linux-fbdev-devel] 2.4 official API ?

[Geert U. <ge...@li...>]

On Fri, 15 Jun 2001, Ghozlane Toumi wrote:
> So the question is how do i support 2.2/2.4 *and* the upcomming 2.5 API
> without maintainig 3 separate sources : i have to work on the internals of
> the driver,
> and i don't feel like updating 3 files every time ...
> 
> any suggestions ?
> how do you guys cope with that ?

Disclaimer: I didn't do any Ruby driver yet. Atyfb is in my (long) todo bucket.

I _think_ you can nicely encapsulate a 2.5 style driver using a 2.4
compatibility layer. Just add some stubs that take care of get_{var,fix}() and
of the extra con argument.

Since these stubs have to be the same for each driver, what we need is some
include file that provides the compatibility layer, and some additional #ifdefs
I guess, or clever macros.

Is this correct, James?

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@li...

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

Re: [Linux-fbdev-devel] 2.4 official API ?

[James S. <jsi...@tr...>]

> Disclaimer: I didn't do any Ruby driver yet. Atyfb is in my (long) todo bucket.
> 
> I _think_ you can nicely encapsulate a 2.5 style driver using a 2.4
> compatibility layer. Just add some stubs that take care of get_{var,fix}() and
> of the extra con argument.

Pretty much. The approach I toke was to write a fbcon-accel.c file much
like fbcon-cfbX and friends. I have it at home. It had one bug in it
which I need to fix. Since people are really interested in this wrapper I
will work on it this weekend along with docs. 

P.S
   One note to make. The only big difference between 2.4.X with the wrapper 
and ruby will be the ablilty to use DMA. The ruby tree can support cards
in DMA/irq mode whereas in 2.4.X you can't. This is due to the console_lock 
which Andrew Morton and I have rewritten to make possible DMA. Using DMA
will mean certain drivers (matrox and aty128) could be really difference
between ruby and 2.4.X even with the wrapper. 

Re: [Linux-fbdev-devel] 2.4 official API ?

[Romain D. <do...@ir...>]

Ghozlane Toumi wrote:
> So the question is how do i support 2.2/2.4 *and* the upcomming 2.5 API
> without maintainig 3 separate sources : i have to work on the internals of
> the driver,
> and i don't feel like updating 3 files every time ...

Didn't yet try ruby, but 2.2/2.4 are extremely similar and
I have just one source file for pm3fb that cover both.
Changes are cosmetic, not functionnal (XXXfb_setup
return an int instead of void, THIS_MODULE as
the first element of XXXfb_ops...)

-- 
DOLBEAU Romain               | l'histoire est entierement vraie, puisque
ENS Cachan / Ker Lann        |     je l'ai imaginee d'un bout a l'autre
do...@ir...             |           -- Boris Vian