Messages in this thread | | | Date | Wed, 11 Apr 2018 15:26:18 -0600 | From | Lina Iyer <> | Subject | Re: [PATCH v5 02/10] dt-bindings: introduce RPMH RSC bindings for Qualcomm SoCs |
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On Tue, Apr 10 2018 at 13:36 -0600, Bjorn Andersson wrote: >On Mon 09 Apr 09:08 PDT 2018, Lina Iyer wrote: > >> On Fri, Apr 06 2018 at 19:14 -0600, Stephen Boyd wrote: >> > Quoting Lina Iyer (2018-04-05 09:18:26) >> > > diff --git a/Documentation/devicetree/bindings/soc/qcom/rpmh-rsc.txt b/Documentation/devicetree/bindings/soc/qcom/rpmh-rsc.txt >[..] >> > > +Example 1: >> > > + >> > > +For a TCS whose RSC base address is is 0x179C0000 and is at a DRV id of 2, the >> > > +register offsets for DRV2 start at 0D00, the register calculations are like >> > > +this - >> > > +First tuple: 0x179C0000 + 0x10000 * 2 = 0x179E0000 >> > > +Second tuple: 0x179E0000 + 0xD00 = 0x179E0D00 >> > > + >> > > + apps_rsc: rsc@179e000 { >> > > + label = "apps_rsc"; >> > > + compatible = "qcom,rpmh-rsc"; >> > > + reg = <0x179e0000 0x10000>, <0x179e0d00 0x3000>; >> > >> > The first reg property overlaps the second one. Does this second one >> > ever move around? I would hardcode it in the driver to be 0xd00 away >> > from the drv base instead of specifying it in DT if it's the same all >> > the time. >[..] >> > >> The DRV is the voter for an execution environment (Linux, Hypervisor, >> ATF) in the RSC. The RSC has a lot of other registers that Linux is not >> privy to. They are access restricted. The memory organization of the RSC >> mandates that we know the DRV id to access registers specific to the >> DRV. Unfortunately, not all RSC have identical DRV configuration and the >> register space is also variable depending on the capability of the RSC. >> There are functionalities supported by other RSCs in the SoC that are >> not supported by the RSC associated with the application processor, >> while not many RSCs' support multiple DRVs. Therefore it doesn't benefit >> describing the whole RSC as it is not usable from Linux (because of >> access restrictions). >> > >I generally prefer that we describe the hardware blocks as accurate as >possible, instead of applying current restrictions on Linux onto the >description. This ensures that we can reuse the binding and drivers in >configurations not considered today. However, afaict we still have the >problem that we need a way to express where in the RSC our TCS sits. > >Regardless of what's right or not, the given example causes the driver >to fail probing, so something needs to be changed. I have been using this in DT and I haven't seen failures. Could you send me the logs?
Thanks, Lina
>(Making the drv size >0xd00 is functional but doesn't really relate to any bondary in the >register space). > >Regards, >Bjorn
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