On Wed, 2016-02-03 at 14:40 +0800, Daniel Kurtz wrote: > > Hi Dan, > > > > Thanks for your comment. > > This solution looks good to me. > > I will change it as your suggestion. > > > > But, I have a question about 'mask out the provided *device virtual* > > address'. > > Are lower 16-bits (or 24-bits for JUMP op) of device virtual address the > > same as device physical address? > > I'm not sure. But I doubt it we can rely on this. > My guess would be that the ioremap only preserves the lower 12 bits > (4k page size). > > > If not, we still need to pass in physical address into CMDQ driver. > > Or, instead of the iommu/slot approach, we can just provide a > registration function for the gce driver. > Each gce consumer could then have a simple gce node, with no slot/address: > > mediatek,gce = <&gce>; > > Then on probe, the gce consumer could pass in its (struct device *) to > gce_register_device(). gce_register_device() could then access the > device's of_node to extract its physical address range, and look up > its physical address in its table of per-soc of > "device_address:gce_subsys_address" entries. If the physical address > is in a valid subsys ranges, the gce_register_device would cache the > subsys address, and an offset in a (struct gce_consumer). > gce_register_device() could then add this struct to a struct list_head > of gce_consumers, and finally return a pointer to it back to the > caller. > > Later, the gce consumer could pass in ths (struct gce_consumer *) when > make gce calls, along with the *offset* (not the physical address or > virtual address) for the register that it wishes to access. Then the > gce driver can simply use the gce_consumer->subsys entry to create a > gce address from the passed in offset. > > This will keep the binding very simple, and would remove the need to > convert from device virtual to physical addresses by the gce consumer, > but require a little more per-gce-consumer setup. > > -Dan Hi Dan, This solution is better. I will use it. Thanks for your suggestion. Thanks, HS Liao -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
