[0/2] Apple M1 PCIe DT bindings

Message

Mark Kettenis May 16, 2021, 9:18 p.m. UTC

From: Mark Kettenis <[e-mail]>

This small series adds bindings for the PCIe controller found on the
Apple M1 SoC.

At this point, the primary consumer for these bindings is U-Boot.
With these bindings U-Boot can bring up the links for the root ports
of the PCIe root complex.  A simple OS driver can then provide
standard ECAM access and manage MSI interrupts to provide access
to the built-in Ethernet and XHCI controllers of the Mac mini.

The Apple controller incorporates Synopsys Designware PCIe logic
to implement its root port.  But unlike other hardware currently
supported by U-Boot and the Linux kernel the Apple hardware
integrates multiple root ports.  As such the existing bindings
for the DWC PCIe interface can't be used.  There is a single ECAM
space for all root space, but separate GPIOs to take the PCI devices
on those ports out of reset.  Therefore the standard "reset-gpio" and
"max-link-speed" properties appear on the child nodes representing
the PCI devices that correspond to the individual root ports.

MSIs are handled by the PCIe controller and translated into "regular
interrupts".  A range of 32 MSIs is provided.  These 32 MSIs can be
distributed over the root ports as the OS sees fit by programming the
PCIe controller port registers.

These series depends on the pinctrl series I sent earlier (with a v2
respin today).


Mark Kettenis (2):
  dt-bindings: pci: Add DT bindings for apple,pcie
  arm64: apple: Add PCIe node

 .../devicetree/bindings/pci/apple,pcie.yaml   | 150 ++++++++++++++++++
 MAINTAINERS                                   |   1 +
 arch/arm64/boot/dts/apple/t8103.dtsi          |  64 ++++++++
 3 files changed, 215 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/apple,pcie.yaml