> 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 -- 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
