Re: [PATCH V2] video: implement a simple framebuffer driver

[Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>]

On Monday 08 April 2013 17:16:37 Andrew Morton wrote:
> On Wed,  3 Apr 2013 20:39:43 -0600 Stephen Warren wrote:
> > A simple frame-buffer describes a raw memory region that may be rendered
> > to, with the assumption that the display hardware has already been set
> > up to scan out from that buffer.
> > 
> > This is useful in cases where a bootloader exists and has set up the
> > display hardware, but a Linux driver doesn't yet exist for the display
> > hardware.
> > 
> > ...
> > 
> > +config FB_SIMPLE
> > +	bool "Simple framebuffer support"
> > +	depends on (FB = y) && OF
> 
> It's sad that this simple little thing requires Open Firmware.  Could
> it be generalised in some way so that the small amount of setup info
> could be provided by other means (eg, module_param) or does the
> dependency go deeper than that?

I second that request. I like the idea of a simple framebuffer driver if it 
helps deprecating fbdev in the long term, but I don't want it to offer an 
excuse not to implement a DRM/KMS driver. In particular adding DT bindings 
would force us to keep supporting the ABI for a (too) long time.

> > +struct simplefb_format simplefb_formats[] = {
> > +	{ "r5g6b5", 16, {11, 5}, {5, 6}, {0, 5}, {0, 0} },
> > +};
> 
> I'll make this static.

-- 
Regards,

Laurent Pinchart