doc/driver-model/pci-info.txt

5 ----------------------
9 Bus number 0 will need to be requested first, and the alias in the device
10 tree file will point to the correct device:
17 	pci: pci-controller {
23 If there is no alias the devices will be numbered sequentially in the device
24 tree.
31 After probing a bus, the available devices will appear in the device tree
37 PCI devices can appear in the flattened device tree. If they do this serves to
38 specify the driver to use for the device. In this case they will be bound at
39 first. Each PCI device node must have a compatible string list as well as a
40 <reg> property, as defined by the IEEE Std 1275-1994 PCI bus binding document
47 		#address-cells = <3>;
48 		#size-cells = <2>;
49 		compatible = "pci-x86";
50 		u-boot,dm-pre-reloc;
56 			#address-cells = <3>;
57 			#size-cells = <2>;
58 			compatible = "pci-bridge";
59 			u-boot,dm-pre-reloc;
63 				#address-cells = <3>;
64 				#size-cells = <2>;
65 				compatible = "pci-bridge";
66 				u-boot,dm-pre-reloc;
74 							"x86-uart";
75 					u-boot,dm-pre-reloc;
88 In this example, the root PCI bus node is the "/pci" which matches "pci-x86"
89 driver. It has a subnode "pcie@17,0" with driver "pci-bridge". "pcie@17,0"
90 also has subnode "topcliff@0,0" which is a "pci-bridge" too. Under that bridge,
91 a PCI UART device "uart@a,1" is described. This exactly reflects the hardware
93 to a downstream device Topcliff chipset. Inside Topcliff chipset, it has a
94 PCIe-to-PCI bridge and all the chipset integrated devices like the PCI UART
95 device are on the PCI bus. Like other devices in the device tree, if we want
96 to bind PCI devices before relocation, "u-boot,dm-pre-reloc" must be declared
99 If PCI devices are not listed in the device tree, U_BOOT_PCI_DEVICE can be used
100 to specify the driver to use for the device. The device tree takes precedence
102 DM_FLAG_PRE_RELOC will be bound before relocation. If neither device tree nor
103 U_BOOT_PCI_DEVICE is provided, the built-in driver (either pci_bridge_drv or
108 -------
110 With sandbox we need a device emulator for each device on the bus since there
111 is no real PCI bus. This works by looking in the device tree node for a
116 		compatible = "pci-generic";
119 			compatible = "sandbox,swap-case";
123 This means that there is a 'sandbox,swap-case' driver at that bus position.
124 Note that the first cell in the 'reg' value is the bus/device/function. See
125 PCI_BDF() for the encoding (it is also specified in the IEEE Std 1275-1994
130 `- * pci-controller @ 05c660c8, 0
131  `-   pci@1f,0 @ 05c661c8, 63488
132   `-   emul@1f,0 @ 05c662c8
134 When accesses go to the pci@1f,0 device they are forwarded to its child, the