On Tue, Feb 06, 2018 at 11:56:50AM -0800, Channa wrote: > On 2018-02-02 03:05, Mark Rutland wrote: > > On Thu, Feb 01, 2018 at 12:39:09PM -0800, Channa wrote: > > > On 2018-02-01 02:44, Mark Rutland wrote: > > > > On Thu, Jan 25, 2018 at 03:55:12PM -0800, Channagoud Kadabi wrote: > > > > > +- llcc-bank-off: > > > > > + Usage: required > > > > > + Value Type: <u32 array> > > > > > + Definition: Offsets of llcc banks from llcc base address starting > > > > > from > > > > > + LLCC bank0. > > > > > + > > > > > +- llcc-broadcast-off: > > > > > + Usage: required > > > > > + Value Type: <u32> > > > > > + Definition: Offset of broadcast register from LLCC bank0 address. > > > > > > > > Please could we use "offset" rather than "off" for both of these? That > > > > way it's obvious these aren't properties for disabling some feature. > > > > > > > > How variable are these offsets in practice? Is the memory map not fixed? > > > > > > The offsets depends on the number of LLCC HW blocks. These number of > > > HW > > > blocks vary from > > > chipset to chipset and new registers could be added that changes the > > > offset. > > > > Surely if new registers are added, we need a new compatible string? > > > > Can't we encode the number of LLCC HW blocks, instead? Presumably that > > would give enough information to cover both llcc-bank-off and > > llcc-broadcast-off. > > > > [...] > > Are you suggesting to move these offset handing out of DTS files and manage > in the driver? Something like that, though it depends on how exactly the offsets can be derived. Using reg entries, as Matt suggested, sounds better though. > > > > > +compatible devices: > > > > > + qcom,sdm845-llcc > > > > > > > > Huh? The "qcom,sdm845-llcc" bindings wasn't described above, and it's > > > > not clear what this means. > > > > > > > > > + > > > > > +Example: > > > > > + > > > > > + qcom,system-cache@1300000 { > > > > > + compatible = "qcom,llcc-core", "syscon", "simple-mfd"; > > > > > > > > This looks very wrong. Why do you need syscon and simple-mfd? > > > > > > LLCC HW block has 3 functionalities: > > > System cache core, ECC & AMON drivers for debugging. > > > All three drivers use the same register space for configuration, > > > status etc. > > > In order to avoid remapping the same address region across multiple > > > drivers, > > > I have implemented this driver as a syncon and simple-mfd. > > > > Please don't do that; that's completely dependent on Linux > > implementation details. > > Why do you think simple-mfd is not good here? The LLCC HW clock is outside > of CPUSS and has > multiple functional blocks. For one thing, there's no need for this to be a syscon *and* a simple-mfd. W.R.T. simple-mfd, I think it would bet better to decompose the device in a top-level driver, as I described in my prior reply, rather than describing a set of drivers (which are not themselves HW). > > > > > +- cache-slices: > > > > > + Usage: required > > > > > + Value type: <prop-encoded-array> > > > > > + Definition: The tuple has phandle to llcc device as the first > > > > > argument and the > > > > > + second argument is the usecase id of the client. > > > > > > > > What is a "usecase id" ? > > > > > > Usecase id for use case that wants to use system cache for eg: > > > video-encode > > > and video-decode > > > > Sure, but how is the value used? Is it the index of a slice? Or > > something more abstract? > > This is used as an index to the SCT (System cache Table) configuration > data that controls the behavior of each cache slice. Ok. Where does that SCT live? Is that in HW? Is it programmed by SW, or statically configured for a given platform? Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html