On Fri, Nov 28, 2008 at 07:43:31AM +0800, Jaya Kumar wrote: > On Fri, Nov 28, 2008 at 4:01 AM, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote: > > On Wed, Nov 26, 2008 at 12:51:27AM -0500, Jaya Kumar wrote: > >> On Tue, Nov 25, 2008 at 11:15 PM, David Brownell <david-b@xxxxxxxxxxx> wrote: > >> > On Tuesday 25 November 2008, Eric Miao wrote: > >> >> Using a bit mask will be more generic if the GPIOs are not contiguous. > >> >> Yet I still doubt this will be generic enough to be added to gpiolib. > >> > > >> > My expectation for this kind of mechanism was that systems who need > >> > to craft another parallel bus out of GPIO pins would be doing this > >> > with some system-specific utility functions. > >> > > >> > So my "is it generic enough" question is more at the level of "Are > >> > there enough Linux systems that need this sort of thing to justify > >> > generic support?". I happen not to have come across the need for > >> > such ganged access from Linux (yet). Whereas I've yet to use non-x86 > >> > Linux systems that don't need to manipulate individual GPIO pins... > >> > >> I have come across the following scenarios where a bus set of gpio is useful: > >> - Broadsheet E-Ink controller (uses 16-bit data bus over GPIO) > >> framebuffer device (this patch is for this) > >> - Apollo/Hecuba E-Ink controller (uses 8-bit data bus over GPIO) > >> framebuffer device > >> - 8-bit parallel IO matrix LCD controllers, such as the Samsung KS108, > >> also Hitachi, etc > > > > We have such a system at work. And we need fast acces to the gpio pins > > when updating the LCD. > > I have not written/looked to deep at the code I just recall it was > > a bit messy and not something I would be proud of submitting to any ML. > > > > Sam > > > > Okay. Please help me understand in case I misunderstood. Are you > saying the code that I posted is too messy? To me, actually I am proud > of it. :-) But if some parts look messy, I'm happy to work on > improving it. I will need some advice though and please advise me on > which parts look messy. Nope - the code we use at work is too messy. What you posted looks much better. Sam -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
