On Wednesday 26 March 2008 15:52, Segher Boessenkool wrote: > > + Dedicated RAM and ROM chips are often used as storage for > > temporary or > > + permanent data in embedded devices. Possible usage include > > non-volatile > > + storage in battery-backed SRAM, semi-permanent storage in > > dedicated SRAM > > + to preserve data accross reboots and firmware storage in > > dedicated ROM. > > + > > + - compatible : should contain the specific model of RAM/ROM > > chip(s) > > + used, if known, followed by either "physmap-ram" or > > "physmap-rom" > > + - reg : Address range of the RAM/ROM chip > > + - bank-width : Width (in bytes) of the RAM/ROM bank. Equal to the > > + device width times the number of interleaved chips. > > + - device-width : (optional) Width of a single RAM/ROM chip. If > > + omitted, assumed to be equal to 'bank-width'. > > Maybe I'm rehashing some old discussion here, if so, sorry; but why > do you have bank-width and device-width here? What useful information > does it provide? If this is about saying what the preferred (or only > possible) access width is, better names are in order.
device-width isn't used so we can get rid of it. bank-width is used by the map_ram driver for erase operations (mapram_erase in drivers/mtd/chips/map_ram.c). To be honest I'm not sure why it uses such an inefficient approach instead of memsetting the whole area. -- Laurent Pinchart CSE Semaphore Belgium Chaussée de Bruxelles, 732A B-1410 Waterloo Belgium T +32 (2) 387 42 59 F +32 (2) 387 42 75 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
