On 2025/2/12 12:25, Bjorn Helgaas wrote:
[......]
pcie_rc1 and pcie_rc2 share registers in cdns_pcie1_ctrl. By using
different "sophgo,core-id" values, they can distinguish and access
the registers they need in cdns_pcie1_ctrl.
Where does cdns_pcie1_ctrl fit in this example? Does that enclose
both pcie_rc1 and pcie_rc2?
cdns_pcie1_ctrl is defined as a syscon node, which contains registers
shared by pcie_rc1 and pcie_rc2. In the binding yaml file, I drew a
diagram to describe the relationship between them, copy here for your
quick reference:
+ +-- Core (Link0) <---> pcie_rc1 +-----------------+
+ | | |
+ Cadence IP 2 --+ | cdns_pcie1_ctrl |
+ | | |
+ +-- Core (Link1) <---> pcie_rc2 +-----------------+
The following is an example with cdns_pcie1_ctrl added. For simplicity,
I deleted pcie_rc0.
pcie_rc1: pcie@7062000000 {
compatible = "sophgo,sg2042-pcie-host";
...... // host bride level properties
linux,pci-domain = <1>;
sophgo,core-id = <0>;
sophgo,syscon-pcie-ctrl = <&cdns_pcie1_ctrl>;
port {
// port level properties
vendor-id = <0x1f1c>;
device-id = <0x2042>;
num-lanes = <2>;
};
};
pcie_rc2: pcie@7062800000 {
compatible = "sophgo,sg2042-pcie-host";
...... // host bride level properties
linux,pci-domain = <2>;
sophgo,core-id = <1>;
sophgo,syscon-pcie-ctrl = <&cdns_pcie1_ctrl>;
port {
// port level properties
vendor-id = <0x1f1c>;
device-id = <0x2042>;
num-lanes = <2>;
}
};
cdns_pcie1_ctrl: syscon@7063800000 {
compatible = "sophgo,sg2042-pcie-ctrl", "syscon";
reg = <0x70 0x63800000 0x0 0x800000>;
};
