Hi, On Fri, Feb 15, 2013 at 08:30:32AM -0800, Tony Lindgren wrote: > * Santosh Shilimkar [130215 05:34]: > > On Friday 15 February 2013 06:57 PM, Russell King - ARM Linux wrote: > > >On Fri, Feb 15, 2013 at 06:56:47PM +0530, Santosh Shilimkar wrote: > > >>Whats your view on use of arch_ioremap_caller() hook ? This can allow > > >>us to avoid the dual ioremap() issue discussed here if the hook > > >>maintains the list of mapped ios. > > >> > > >>I was even thinking of having such intelligence within the core > > >>ioremap code but thought that might be too invasive. > > > > > >Why do you even need it? There's no problem with ioremapping the same > > >space multiple times (you end up with multiple mappings but that > > >shouldn't be a problem, except for the additional space used.) > > > > > It just waste of iospace and Tony insisted to have just single ioremap() > > hence all this discussion > > The main goal is to avoid duplicating data both in hwmod and DT. > That's pretty much solved as we can have the driver probe populate > the common data for hwmod from DT as Santosh has already demonstrated. > > Then we also want the driver specific idle and reset code to be done > in the drivers rather than in hwmod and glue it together with hwmod > using runtime PM. The biggest issue there is how do we reset and idle > some piece of hardware for PM purposes when there's no driver loaded. right, this will be a tough nut to crack. I guess the only way would be reset all IPs early in the boot process, before even creating the platform-devices. Can we do that ? I mean, from omap_device_build_from_dt() we have access to address space of all devices, through ti,hwmods we can figure out which hwmods are linked to that particular device, so whenever you build a device, you could just call _reset(). The only problem is that now omap_device_build_from_dt() is called after we notify that a new device/driver pair has been registered with the platform_bus, right ? So we would still need a way to call _reset() for those which are on DTS but don't have a driver bound to them... -- balbi