Re: [PATCH 2.6.19-rc1 full] drivers: add LCD support

Franck Bui-Huu
2006-10-23T16:51:18Z

On 10/23/06, Miguel Ojeda <maxextreme@gmail.com> wrote:
> On 10/23/06, Franck Bui-Huu <vagabon.xyz@gmail.com> wrote:
> >
> > [ note I'm not familiar with lcds...just try to understand what you've
> > done ]
> >
> > What I was worry about is that you actually wrote a frame buffer
> > driver, which are normally located in drivers/video, and put it in a
> > new directory drivers/auxdisplay. So now we have two places for frame
> > buffer drivers. It looks like, now some frame buffer drivers in
> > drivers/video should be moved in drivers/auxdisplay, shouldn't it ?
> >
> > Maybe just a stupid idea but why not restructuring the thing like:
> >
> > drivers
> > |-- display
> > | |-- video
> > | |-- aux
> > | |-- fbmem.c
> > | |-- ...
> >
> >
>
> Yes, I got your idea in your first message, and well, that was
> discussed (however, not being a fbdev), and the people thought that
> putting them together will, maybe, cause confusion; so having them out
> from drivers/video should be better. Your idea, which merge them into
> a "drivers/display" could be a good one, but I don't think people will
> like to change such critical tree right now. Also, I'm not the one who
> maintain such tree, so my opinion won't make changes about that ;)
>

well, if it is the right thing to do, why not doing it. (note: I don't
claim it's the right thing to do though). Futhermore such change is
going to move a lot of files _but_ if after the move it compiles, then
it works...

> >
> > Another point: does the ks0108 controller is only used with the 'cfag'
> > display ? If not, suppose I'm using the same controller with another
> > lcd different from 'cfga'...Am I supposed to reuse your code in
> > cfag12864b.c ?
> >
>
> No. You are supposed to _use_ the ks0108's exported functions: I split
> the code into the ks0108 and the cfag12864b because I thought it was
> the logical way, as the cfag12864b LCD just send the data through two
> different ks0108 controllers. The same way, you can use the ks0108's
> exported functions to create another whateverlcd.c which has one or
> more ks0108 controllers.
>

So, to sum up, if I have a lcd named 'foo_lcd' which use 4 ks0108
controllers (256x128), and want to make your fb driver work on it, I
need to copy your cfag12864b.c file, rename it to foo_lcd256128.c and
just change the number of controllers, is that correct ?

> >
> > BTW, did you try to mmap your fbdev ? Does it work ?
> >
>
> Why it shouldn't? It doesn't work for you? AFAIK, it is a usual fbdev,
> and you can map any fbdev as they are simple character file devices.
>

well you actually haven't answered to the initial question... I
suspect it won't work since you haven't setup "info->fix.smem_start"
anywhere. But I may be wrong since I don't know fb code.

--
Franck