dt-bindings: PCI: Convert generic host binding to DT schema

Convert the generic PCI host binding to DT schema. The derivative Juno,
PLDA XpressRICH3-AXI, and Designware ECAM bindings all just vary in
their compatible strings. The simplest way to convert those to
schema is just add them into the common generic PCI host schema.

The HiSilicon ECAM and Cavium ThunderX PEM bindings have an additional
'reg' entry, but are otherwise the same binding as well.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andrew Murray <andrew.murray@arm.com>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Will Deacon <will@kernel.org>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Rob Herring <robh@kernel.org>

1 files changed, 172 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.yaml b/Documentation/devicetree/bindings/pci/host-generic-pci.yaml
new file mode 100644
index 000000000000..47353d0cd394
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/host-generic-pci.yaml
@@ -0,0 +1,172 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/host-generic-pci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic PCI host controller
+
+maintainers:
+  - Will Deacon <will@kernel.org>
+
+description: |
+  Firmware-initialised PCI host controllers and PCI emulations, such as the
+  virtio-pci implementations found in kvmtool and other para-virtualised
+  systems, do not require driver support for complexities such as regulator
+  and clock management. In fact, the controller may not even require the
+  configuration of a control interface by the operating system, instead
+  presenting a set of fixed windows describing a subset of IO, Memory and
+  Configuration Spaces.
+
+  Configuration Space is assumed to be memory-mapped (as opposed to being
+  accessed via an ioport) and laid out with a direct correspondence to the
+  geography of a PCI bus address by concatenating the various components to
+  form an offset.
+
+  For CAM, this 24-bit offset is:
+
+          cfg_offset(bus, device, function, register) =
+                     bus << 16 | device << 11 | function << 8 | register
+
+  While ECAM extends this by 4 bits to accommodate 4k of function space:
+
+          cfg_offset(bus, device, function, register) =
+                     bus << 20 | device << 15 | function << 12 | register
+
+properties:
+  compatible:
+    description: Depends on the layout of configuration space (CAM vs ECAM
+      respectively). May also have more specific compatibles.
+    oneOf:
+      - description:
+          PCIe host controller in Arm Juno based on PLDA XpressRICH3-AXI IP
+        items:
+          - const: arm,juno-r1-pcie
+          - const: plda,xpressrich3-axi
+          - const: pci-host-ecam-generic
+      - description: |
+          ThunderX PCI host controller for pass-1.x silicon
+
+          Firmware-initialized PCI host controller to on-chip devices found on
+          some Cavium ThunderX processors.  These devices have ECAM-based config
+          access, but the BARs are all at fixed addresses.  We handle the fixed
+          addresses by synthesizing Enhanced Allocation (EA) capabilities for
+          these devices.
+        const: cavium,pci-host-thunder-ecam
+      - description:
+          Cavium ThunderX PEM firmware-initialized PCIe host controller
+        const: cavium,pci-host-thunder-pem
+      - description:
+          HiSilicon Hip06/Hip07 PCIe host bridge in almost-ECAM mode. Some
+          firmware places the host controller in a mode where it is ECAM
+          compliant for all devices other than the root complex.
+        enum:
+          - hisilicon,hip06-pcie-ecam
+          - hisilicon,hip07-pcie-ecam
+      - description: |
+          In some cases, firmware may already have configured the Synopsys
+          DesignWare PCIe controller in RC mode with static ATU window mappings
+          that cover all config, MMIO and I/O spaces in a [mostly] ECAM
+          compatible fashion. In this case, there is no need for the OS to
+          perform any low level setup of clocks, PHYs or device registers, nor
+          is there any reason for the driver to reconfigure ATU windows for
+          config and/or IO space accesses at runtime.
+
+          In cases where the IP was synthesized with a minimum ATU window size
+          of 64 KB, it cannot be supported by the generic ECAM driver, because
+          it requires special config space accessors that filter accesses to
+          device #1 and beyond on the first bus.
+        items:
+          - enum:
+              - marvell,armada8k-pcie-ecam
+              - socionext,synquacer-pcie-ecam
+          - const: snps,dw-pcie-ecam
+      - description:
+          CAM or ECAM compliant PCI host controllers without any quirks
+        enum:
+          - pci-host-cam-generic
+          - pci-host-ecam-generic
+
+  reg:
+    description:
+      The Configuration Space base address and size, as accessed from the parent
+      bus. The base address corresponds to the first bus in the "bus-range"
+      property. If no "bus-range" is specified, this will be bus 0 (the
+      default). Some host controllers have a 2nd non-compliant address range,
+      so 2 entries are allowed.
+    minItems: 1
+    maxItems: 2
+
+  ranges:
+    description:
+      As described in IEEE Std 1275-1994, but must provide at least a
+      definition of non-prefetchable memory. One or both of prefetchable Memory
+      and IO Space may also be provided.
+    minItems: 1
+    maxItems: 3
+
+  dma-coherent: true
+
+required:
+  - compatible
+  - reg
+  - ranges
+
+allOf:
+  - $ref: /schemas/pci/pci-bus.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: arm,juno-r1-pcie
+    then:
+      required:
+        - dma-coherent
+
+  - if:
+      properties:
+        compatible:
+          not:
+            contains:
+              enum:
+                - cavium,pci-host-thunder-pem
+                - hisilicon,hip06-pcie-ecam
+                - hisilicon,hip07-pcie-ecam
+    then:
+      properties:
+        reg:
+          maxItems: 1
+
+examples:
+  - |
+
+    bus {
+        #address-cells = <2>;
+        #size-cells = <2>;
+        pcie@40000000 {
+            compatible = "pci-host-cam-generic";
+            device_type = "pci";
+            #address-cells = <3>;
+            #size-cells = <2>;
+            bus-range = <0x0 0x1>;
+
+            // CPU_PHYSICAL(2)  SIZE(2)
+            reg = <0x0 0x40000000  0x0 0x1000000>;
+
+            // BUS_ADDRESS(3)  CPU_PHYSICAL(2)  SIZE(2)
+            ranges = <0x01000000 0x0 0x01000000  0x0 0x01000000  0x0 0x00010000>,
+                     <0x02000000 0x0 0x41000000  0x0 0x41000000  0x0 0x3f000000>;
+
+            #interrupt-cells = <0x1>;
+
+            // PCI_DEVICE(3)  INT#(1)  CONTROLLER(PHANDLE)  CONTROLLER_DATA(3)
+            interrupt-map = <   0x0 0x0 0x0  0x1  &gic  0x0 0x4 0x1>,
+                            < 0x800 0x0 0x0  0x1  &gic  0x0 0x5 0x1>,
+                            <0x1000 0x0 0x0  0x1  &gic  0x0 0x6 0x1>,
+                            <0x1800 0x0 0x0  0x1  &gic  0x0 0x7 0x1>;
+
+            // PCI_DEVICE(3)  INT#(1)
+            interrupt-map-mask = <0xf800 0x0 0x0  0x7>;
+        };
+    };
+...