On 7/24/2019 7:18 AM, Stephen Boyd wrote:
Quoting David Dai (2019-07-23 14:48:42)
On 7/23/2019 7:42 AM, Stephen Boyd wrote:
Quoting David Dai (2019-07-19 13:32:23)
+- compatible : shall contain only one of the following:
+ "qcom,sdm845-bcm-voter",
+
+Examples:
+
+apps_rsc: rsc@179c0000 {
But there isn't a reg property.
I'll change this to the generic example with just apps_rsc: rsc {
+ label = "apps_rsc";
Is label required?
Any answer?
Not required.
+ compatible = "qcom,rpmh-rsc";
+
+ apps_bcm_voter: bcm_voter {
+ compatible = "qcom,sdm845-bcm-voter";
+ };
+}
+
+disp_rsc: rsc@179d0000 {
+ label = "disp_rsc";
+ compatible = "qcom,rpmh-rsc";
+
+ disp_bcm_voter: bcm_voter {
+ compatible = "qcom,sdm845-bcm-voter";
+ };
+}
diff --git a/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt b/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt
index 5c4f1d9..27f9ed9 100644
--- a/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt
+++ b/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt
[...]
+
+mem_noc: interconnect@1380000 {
+ compatible = "qcom,sdm845-mem_noc";
+ reg = <0 0x1380000 0 0x27200>;
+ #interconnect-cells = <1>;
+ qcom,bcm-voter = <&apps_bcm_voter>, <&disp_bcm_voter>;
+};
How does a consumer target a particular RSC? For example, how can
display decide to use the disp_bcm_voter node from mem_noc here? Maybe
you can add that consumer to the example?
I was thinking that the association between the bcm voters and the icc
nodes would be handled by the interconnect provider, and that there
would be a set of display specific icc nodes with their own unique IDs
that the consumers could reference. I will mention this as part of the
description and provide an example.
Ex: interconnects = <&mmss_noc MASTER_MDP0_DISP &mem_noc SLAVE_EBI_DISP>;
It looks backwards to me. Don't the consumers want to consume a
particular RSC, i.e. apps or display RSC, so they can choose where to
put the bcm vote and then those RSCs want to find MMIO registers for
mmss_noc or mem_noc that they have to write to tune something else like
QoS? If the MMIO space is the provider then I'm lost how it can
differentiate between the RSCs that may be targetting the particular
NoC.
The way that I view this is that the consumers consume both bandwidth
and QoS from these physical NoC devices by getting some path between two
endpoints on these different NoCs and applying some constraints. The NoC
providers can accomplish that either by writing to MMIO spaces or by
talking to some remote processor/hardware to tune its clock speed. The
consumer doesn't interact with the RSCs directly, but can select a
different bcm voter based on the endpoints that are associated with a
particular bcm(apps or disp rsc). Each node(endpoints) will have its own
BCM designation and an unique bcm voter.
Maybe I've just completely missed something and this is all decided
already. If so, sorry, I'm just trying to understand.
No problem, this just means I need to do a better job of explaining.
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