On Fri, Nov 9, 2018 at 4:38 PM Alex Elder <elder@xxxxxxxxxx> wrote: > > On 11/7/18 8:59 AM, Rob Herring wrote: > > On Tue, Nov 6, 2018 at 6:33 PM Alex Elder <elder@xxxxxxxxxx> wrote: > >> > >> Add the binding definitions for the "qcom,ipa" and "qcom,rmnet-ipa" > >> device tree nodes. > >> > >> Signed-off-by: Alex Elder <elder@xxxxxxxxxx> > >> --- > >> .../devicetree/bindings/soc/qcom/qcom,ipa.txt | 136 ++++++++++++++++++ > >> .../bindings/soc/qcom/qcom,rmnet-ipa.txt | 15 ++ > >> 2 files changed, 151 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,ipa.txt > >> create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,rmnet-ipa.txt > >> > >> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,ipa.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,ipa.txt > >> new file mode 100644 > >> index 000000000000..d4d3d37df029 > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,ipa.txt > >> @@ -0,0 +1,136 @@ > >> +Qualcomm IPA (IP Accelerator) Driver > > > > Bindings are for h/w not drivers. > > OK. I'll drop " Driver". > > >> + > >> +This binding describes the Qualcomm IPA. The IPA is capable of offloading > >> +certain network processing tasks (e.g. filtering, routing, and NAT) from > >> +the main processor. The IPA currently serves only as a network interface, > >> +providing access to an LTE network available via a modem. > >> + > >> +The IPA sits between multiple independent "execution environments," > >> +including the AP subsystem (APSS) and the modem. The IPA presents > >> +a Generic Software Interface (GSI) to each execution environment. > >> +The GSI is an integral part of the IPA, but it is logically isolated > >> +and has a distinct interrupt and a separately-defined address space. > >> + > >> + ---------- ------------- --------- > >> + | | |G| |G| | | > >> + | APSS |===|S| IPA |S|===| Modem | > >> + | | |I| |I| | | > >> + ---------- ------------- --------- > >> + > >> +See also: > >> + bindings/interrupt-controller/interrupts.txt > >> + bindings/interconnect/interconnect.txt > >> + bindings/soc/qcom/qcom,smp2p.txt > >> + bindings/reserved-memory/reserved-memory.txt > >> + bindings/clock/clock-bindings.txt > >> + > >> +All properties defined below are required. > >> + > >> +- compatible: > >> + Must be one of the following compatible strings: > >> + "qcom,ipa-sdm845-modem_init" > >> + "qcom,ipa-sdm845-tz_init" > > > > Normal order is <vendor>,<soc>-<ipblock>." > > I'll use "qcom,sdm845-ipa-modem-init" and "qcom,sdm845-ipa-tz-init". > (Or just "qcom,sdm845-ipa", depending on the outcome of the discussion > below.) > > > Don't use '_'. > > OK. > > > What's the difference between these 2? It can't be detected somehow? > > There is some early initialization, including loading some firmware, > that must be done by trusted code. That can be done by either Trust > Zone or the modem. If it's done by the modem, there is an additional > step required during initialization so the modem can tell the AP > that it has done its part, and the AP can finish IPA initialization. > > There is no way of detecting (e.g. by probing hardware) which is > in effect so we use DT. I discussed this with Bjorn, who said that > this was a situation seen elsewhere and that using compatible strings > was the way he suggested to address it. Okay. However, if this is common for QCom blocks maybe we should reconsider. I think compatible makes sense if the programming model changes. > > This might be better expressed as a property. Then if Trustzone > > initializes things, it can just add a property. > > A Boolean property to distinguish them would be fine as well, but > I would like to address this "common" problem consistently. > > Bjorn, would you please weigh in? > > >> + > >> +-reg: > >> + Resources specyfing the physical address spaces of the IPA and GSI. > > > > typo > > > >> + > >> +-reg-names: > >> + The names of the address space ranges defined by the "reg" property. > >> + Must be "ipa" and "gsi". > >> + > >> +- interrupts-extended: > > > > Use 'interrupts' here and describe what they are and the order. What > > they are connected to (and the need for interrupts-extended) is > > outside the scope of this binding. > > I used interrupts-extended because there were two interrupt parents > (a "normal" interrupt controller and the interrupt controller implemented > for SMP2P input). A paragraph here: > bindings/interrupt-controller/interrupts.txt > recommends "interrupts-extended" in that case. > > I have no objection to using just "interrupts" but can you tell me what > I misunderstood? It seems like I need to do "interrupts-extended". Yes, in the dts you should use interrupts-extended. However, for documentation purposes that aspect is not important. So we just use interrupts most everywhere. Rob
