On Fri, Jun 18, 2010 at 01:47:28PM +0100, Lorenzo Pieralisi wrote: > I think chip-select addressing should be used if that is the way HW handles > it. If the device is described through a memory-mapping, > ex. snippet follows: > > ser...@101f2000 { > compatible = "arm,pl011"; > reg = <0x101f2000 0x1000 >; > };
Primecell devices aren't platform devices. They have no 'id' field as such. Instead, modern implementations have PCI-like IDs. > struct map_desc { > unsigned long virtual; > unsigned long pfn; > unsigned long length; > unsigned int type; > }; > > static struct map_desc realview_eb_io_desc[] __initdata = { > { > .virtual = IO_ADDRESS(REALVIEW_SYS_BASE), > .pfn = __phys_to_pfn(REALVIEW_SYS_BASE), > .length = SZ_4K, > .type = MT_DEVICE, > }, ... These mappings are entirely arbitary, and change according to the implementation of the platform. Some platforms want to avoid using ioremap() to create 4K page mappings for their devices, so instead they statically map them and arrange for ioremap() to know about that static mapping. Given that PAGE_OFFSET can be changed, it would be absolutely silly to put this into the device tree. _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss