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Diffstat (limited to 'Documentation/devicetree/bindings/pci/nvidia,tegra20-pcie.txt')
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1 files changed, 161 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pci/nvidia,tegra20-pcie.txt b/Documentation/devicetree/bindings/pci/nvidia,tegra20-pcie.txt new file mode 100644 index 00000000000..90c112f671d --- /dev/null +++ b/Documentation/devicetree/bindings/pci/nvidia,tegra20-pcie.txt @@ -0,0 +1,161 @@ +NVIDIA Tegra PCIe controller + +Required properties: +- compatible: "nvidia,tegra20-pcie" +- device_type: Must be "pci" +- reg: A list of physical base address and length for each set of controller + registers. Must contain an entry for each entry in the reg-names property. +- reg-names: Must include the following entries: + "pads": PADS registers + "afi": AFI registers + "cs": configuration space region +- interrupts: A list of interrupt outputs of the controller. Must contain an + entry for each entry in the interrupt-names property. +- interrupt-names: Must include the following entries: + "intr": The Tegra interrupt that is asserted for controller interrupts + "msi": The Tegra interrupt that is asserted when an MSI is received +- pex-clk-supply: Supply voltage for internal reference clock +- vdd-supply: Power supply for controller (1.05V) +- bus-range: Range of bus numbers associated with this controller +- #address-cells: Address representation for root ports (must be 3) + - cell 0 specifies the bus and device numbers of the root port: + [23:16]: bus number + [15:11]: device number + - cell 1 denotes the upper 32 address bits and should be 0 + - cell 2 contains the lower 32 address bits and is used to translate to the + CPU address space +- #size-cells: Size representation for root ports (must be 2) +- ranges: Describes the translation of addresses for root ports and standard + PCI regions. The entries must be 6 cells each, where the first three cells + correspond to the address as described for the #address-cells property + above, the fourth cell is the physical CPU address to translate to and the + fifth and six cells are as described for the #size-cells property above. + - The first two entries are expected to translate the addresses for the root + port registers, which are referenced by the assigned-addresses property of + the root port nodes (see below). + - The remaining entries setup the mapping for the standard I/O, memory and + prefetchable PCI regions. The first cell determines the type of region + that is setup: + - 0x81000000: I/O memory region + - 0x82000000: non-prefetchable memory region + - 0xc2000000: prefetchable memory region + Please refer to the standard PCI bus binding document for a more detailed + explanation. +- clocks: List of clock inputs of the controller. Must contain an entry for + each entry in the clock-names property. +- clock-names: Must include the following entries: + "pex": The Tegra clock of that name + "afi": The Tegra clock of that name + "pcie_xclk": The Tegra clock of that name + "pll_e": The Tegra clock of that name + +Root ports are defined as subnodes of the PCIe controller node. + +Required properties: +- device_type: Must be "pci" +- assigned-addresses: Address and size of the port configuration registers +- reg: PCI bus address of the root port +- #address-cells: Must be 3 +- #size-cells: Must be 2 +- ranges: Sub-ranges distributed from the PCIe controller node. An empty + property is sufficient. +- nvidia,num-lanes: Number of lanes to use for this port. Valid combinations + are: + - Root port 0 uses 4 lanes, root port 1 is unused. + - Both root ports use 2 lanes. + +Example: + +SoC DTSI: + + pcie-controller { + compatible = "nvidia,tegra20-pcie"; + device_type = "pci"; + reg = <0x80003000 0x00000800 /* PADS registers */ + 0x80003800 0x00000200 /* AFI registers */ + 0x90000000 0x10000000>; /* configuration space */ + reg-names = "pads", "afi", "cs"; + interrupts = <0 98 0x04 /* controller interrupt */ + 0 99 0x04>; /* MSI interrupt */ + interrupt-names = "intr", "msi"; + + bus-range = <0x00 0xff>; + #address-cells = <3>; + #size-cells = <2>; + + ranges = <0x82000000 0 0x80000000 0x80000000 0 0x00001000 /* port 0 registers */ + 0x82000000 0 0x80001000 0x80001000 0 0x00001000 /* port 1 registers */ + 0x81000000 0 0 0x82000000 0 0x00010000 /* downstream I/O */ + 0x82000000 0 0xa0000000 0xa0000000 0 0x10000000 /* non-prefetchable memory */ + 0xc2000000 0 0xb0000000 0xb0000000 0 0x10000000>; /* prefetchable memory */ + + clocks = <&tegra_car 70>, <&tegra_car 72>, <&tegra_car 74>, + <&tegra_car 118>; + clock-names = "pex", "afi", "pcie_xclk", "pll_e"; + status = "disabled"; + + pci@1,0 { + device_type = "pci"; + assigned-addresses = <0x82000800 0 0x80000000 0 0x1000>; + reg = <0x000800 0 0 0 0>; + status = "disabled"; + + #address-cells = <3>; + #size-cells = <2>; + + ranges; + + nvidia,num-lanes = <2>; + }; + + pci@2,0 { + device_type = "pci"; + assigned-addresses = <0x82001000 0 0x80001000 0 0x1000>; + reg = <0x001000 0 0 0 0>; + status = "disabled"; + + #address-cells = <3>; + #size-cells = <2>; + + ranges; + + nvidia,num-lanes = <2>; + }; + }; + + +Board DTS: + + pcie-controller { + status = "okay"; + + vdd-supply = <&pci_vdd_reg>; + pex-clk-supply = <&pci_clk_reg>; + + /* root port 00:01.0 */ + pci@1,0 { + status = "okay"; + + /* bridge 01:00.0 (optional) */ + pci@0,0 { + reg = <0x010000 0 0 0 0>; + + #address-cells = <3>; + #size-cells = <2>; + + device_type = "pci"; + + /* endpoint 02:00.0 */ + pci@0,0 { + reg = <0x020000 0 0 0 0>; + }; + }; + }; + }; + +Note that devices on the PCI bus are dynamically discovered using PCI's bus +enumeration and therefore don't need corresponding device nodes in DT. However +if a device on the PCI bus provides a non-probeable bus such as I2C or SPI, +device nodes need to be added in order to allow the bus' children to be +instantiated at the proper location in the operating system's device tree (as +illustrated by the optional nodes in the example above). |