* Tomi Valkeinen <tomi.valkeinen@xxxxxx> [130322 08:34]: > On 2013-03-22 17:18, Tony Lindgren wrote: > > * Tomi Valkeinen <tomi.valkeinen@xxxxxx> [130322 01:30]: > >> Hi Tony, > >> > >> As you probably know, Overo is a very basic omap board to which you can > >> attach different add-on modules, like LCD module. In the current overo > >> board file we always add multiple LCD devices, of which the user should > >> only use one (the one on his module). This model of allowing multiple > >> LCD devices on the same video bus is causing headaches in the dss land, > >> and I'm removing support for it. > > > > OK yes sounds like they should be all selectable, and only the selected > > one gets initialized. > > > >> So what we should do is add only the LCD device that you actually have > >> attached. With DT this will probably be handled with separate dts files, > >> depending on the add-on module. > >> > >> How should this be handled with board files? Is it ok to add a board > >> specific kernel boot argument, parsed in the board file, which tells the > >> add-on board? > > > > At this point I'd stay away adding any kind of custom handling to the > > board-*.c files as that will make the task of removing them harder. And > > a kernel boot argument is something we'd have to support in the future. > > So if something gets added, it should be a Linux generic boot argument. > > > > Some of these add on boards can be detected over i2c, but it seems as > > DT is the way to go in the long run in this case. > > > >> We have similar situation in some other boards also. > > > > Yeah. There's the capebus coming that might even allow hotplugging > > some of these add on boards eventually. > > > > How about just make PANEL_LGPHILIPS_LB035Q02 depends on !PANEL_XYZ_DPI > > in drivers/video/omap2/displays/Kconfig and add some comments for now? > > > > That way people can still select LB035Q02 but not for generic > > configurations. > > Well, I don't want to disable a panel driver totally because of one > board. And it's more complex than that. For overo we have three displays > on the same DPI bus (using the names assigned in the board file): dvi, > lcd43, lcd35. So even if the LB035Q02 would be disabled, we have dvi and > lcd43 which conflict. > > I also would stay away from custom boot args. So I guess that leaves us > only the compile time option. Either so that the overo board-file needs > to be modified by the user to change the add-on board, or a Kconfig > option to select the add-on board under "TI OMAP2/3/4 Specific Features" > menu. > > Would the Kconfig option be acceptable? Yes I think that's better than cmdline option in this case considering that the cmdline option won't be needed at some point in the future. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
