On Wed, Oct 27, 2021 at 4:54 PM Rob Herring <robh@xxxxxxxxxx> wrote: > > On Tue, Oct 26, 2021 at 4:27 PM Jim Quinlan <james.quinlan@xxxxxxxxxxxx> wrote: > > > > On Mon, Oct 25, 2021 at 6:24 PM Rob Herring <robh@xxxxxxxxxx> wrote: > > > > > > On Fri, Oct 22, 2021 at 10:06:54AM -0400, Jim Quinlan wrote: > > > > Similar to the regulator bindings found in "rockchip-pcie-host.txt", this > > > > allows optional regulators to be attached and controlled by the PCIe RC > > > > driver. That being said, this driver searches in the DT subnode (the EP > > > > node, eg pci@0,0) for the regulator property. > > > > > > > > The use of a regulator property in the pcie EP subnode such as > > > > "vpcie12v-supply" depends on a pending pullreq to the pci-bus.yaml > > > > file at > > > > > > > > https://github.com/devicetree-org/dt-schema/pull/54 > > > > > > > > Signed-off-by: Jim Quinlan <jim2101024@xxxxxxxxx> > > > > --- > > > > .../bindings/pci/brcm,stb-pcie.yaml | 23 +++++++++++++++++++ > > > > 1 file changed, 23 insertions(+) > > > > > > > > diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml > > > > index b9589a0daa5c..fec13e4f6eda 100644 > > > > --- a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml > > > > +++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml > > > > @@ -154,5 +154,28 @@ examples: > > > > <0x42000000 0x1 0x80000000 0x3 0x00000000 0x0 0x80000000>; > > > > brcm,enable-ssc; > > > > brcm,scb-sizes = <0x0000000080000000 0x0000000080000000>; > > > > + > > > > + /* PCIe bridge */ > > > > > > More specifically, the root port. > > > > > > > + pci@0,0 { > > > > + #address-cells = <3>; > > > > + #size-cells = <2>; > > > > + reg = <0x0 0x0 0x0 0x0 0x0>; > > > > + device_type = "pci"; > > > > + ranges; > > > > + > > > > + /* PCIe endpoint */ > > > > + pci@0,0 { > > > > + device_type = "pci"; > > > > > > This means this device is a PCI bridge which wouldn't typically be the > > > endpoint. Is that intended? > > Hi Rob, > > > > I'm not sure I understand what you are saying -- do you want the > > innermost node to be named something like ep-pci@0,0, and its > > containing node pci-bridge@0,0? Or, more likely, I'm missing the > > point. If my DT subtree is this > > I'm confused as to how a bridge is the endpoint. If it is a bridge > (which 'device_type = "pci"' means it is), then there should be > another PCI device under it. That may or may not have a DT node. I did not know that device_type="pci" implies that it must be a bridge; [1] says "device_type" is deprecated for PCI and [2] defers to Open Firmware EEE 1275, which is not free AFAICT. Do you have better URLs that describe this? At any rate, I will remove the device_type="pci" from the innermost DT node, and resubmit. > > > pcie@8b10000 { > > compatible = "brcm,bcm7278-pcie"; > > .... > > pci-bridge@0,0 { > > reg = <0x0 0x0 0x0 0x0 0x0>; /* bus 0 */ > > ..... > > pci-ep@0,0,0 { > > reg = <0x10000 0x0 0x0 0x0 0x0>; /* bus 1 */ > > vpcie3v3-supply = <&vreg8>; > > ... > > } > > } > > } > > > > then the of_nodes appear to align correctly with the devices: > > > > $ cd /sys/devices/platform/ > > $ cat 8b10000.pcie/of_node/name > > pcie > > $ cat 8b10000.pcie/pci0000:00/0000:00:00.0/of_node > > pci-bridge > > $ cat 8b10000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/of_node/name > > pci-ep > > What does 'lspci -tv' show? $ lspci -tv -+-[0000:01]---00.0 Intel Corporation Wireless 7260 \-[0000:00]---00.0 Broadcom Inc. and subsidiaries Device 7278 > > > > > and the EP device works of course. I've even printed out the > > device_node structure in the EP driver's probe and it is as expected. > > I've noticed that examples such as > > "arch/arm64/boot/dts/nvidia/tegra186.dtsi" have the EP node (eg > > pci@1,0) directly under the > > host bridge DT node (pcie@10003000). I did try doing that, but the EP > > device's probe is given a NUL device_node pointer. > > If you want a complex example I know that's right, then see hikey970. Thanks, will look. Jim [1] https://buildmedia.readthedocs.org/media/pdf/devicetree-specification/latest/devicetree-specification.pdf [2] https://www.openfirmware.info/data/docs/bus.pci.pdf > > Rob
