“Is it necessary that the nodes shown in "lspci" output, have to be defined in device tree ?

[avinashh]

Hi,

“Is it necessary that the nodes shown in "lspci" output, have to be defined in device tree ? I have device tree file for P2041RDB. In that only one node is created for pci i.e. bus 0. Now I have customized the reference board and connected one pcie-pci bridge to bus 0 and four pci devices are connected to that bridge. So in my lspci output, six node is showing. So is it necessary that I have to declare it all in device tree.”

regards,

Avinash

[yipingwang]

Hello Avinash,

No need to define PCIe devices in the device tree. In fact, only PCIe controllers are defined in the dts file.

Have a great day,
TIC

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[avinashh]

Thanks for your response Yiping.

One thing I also want to clear is that if it is necessary to declare the pcie/pci devices, if so, how is the interrupt number assigned to them. I have a dts for pci controllrer bellow,

pci1: pcie@ffe201000 {
reg = <0xf 0xfe201000 0 0x1000>;
ranges = <0x2000000 0x0 0xe0000000 0xc 0x20000000 0x0 0x20000000
0x1000000 0x0 0x0 0xf 0xf8010000 0x0 0x10000>;
compatible = "fsl,p2041-pcie", "fsl,qoriq-pcie-v2.2", "fsl,qoriq-pcie";
device_type = "pci";
#size-cells = <2>;
#address-cells = <3>;
bus-range = <0 0xff>;
clock-frequency = <33333333>;
interrupts = <16 2 1 14>;
fsl,iommu-parent = <&pamu0>;
fsl,liodn-reg = <&guts 0x504>;

pcie@0{
ranges = <0x2000000 0 0xe0000000 0x2000000
0 0xe0000000 0 0x20000000
0x1000000 0 0x0 0x1000000
0 0x0 0 0x10000>;
reg = <0 0 0 0 0>;
#interrupt-cells = <1>;
#size-cells = <2>;
#address-cells = <3>;
device_type = "pci";
interrupts = <16 2 1 14>;
interrupt-map-mask = <0xf800 0 0 7>;
interrupt-map = <

0 0 0 1 &mpic 41 1 0 0

0 0 0 2 &mpic 5 1 0 0

0 0 0 3 &mpic 6 1 0 0

0 0 0 4 &mpic 7 1 0 0 >;

};
};

The output of lspci -t is

-[0000:00]---00.0-[01-07]----00.0-[02-07]--+-01.0-[03]----00.0
                                                                  +-02.0-[04-05]----00.0-[05]--+-00.0
                                                                  |                                            +-01.0
                                                                  |                                            +-02.0
                                                                  |                                             \-03.0
                                                                  +-03.0-[06]----00.0
                                                                  \-04.0-[07]----00.0

When I execute the "lspci -vvv" command all my device are assigned with an interrupt number, how is this interrupt number assigned, how should I modify the interrupt number, cause i'm experiencing an interrupt failure when I run the device tester program. How should I do the interrupt mapping for this assembly?

[yipingwang]

Interrupt specifiers consists of 4 cells encoded as follows:

   <1st-cell>   interrupt-number
                Identifies the interrupt source.  The meaning
                depends on the type of interrupt.

                Note: If the interrupt-type cell is undefined
                (i.e. #interrupt-cells = 2), this cell
                should be interpreted the same as for
                interrupt-type 0-- i.e. an external or
                normal SoC device interrupt.

   <2nd-cell>   level-sense information, encoded as follows:
                    0 = low-to-high edge triggered
                    1 = active low level-sensitive
                    2 = active high level-sensitive
                    3 = high-to-low edge triggered

   <3rd-cell>   interrupt-type

                The following types are supported:

                  0 = external or normal SoC device interrupt
                      The interrupt-number cell contains
                      the SoC device interrupt number.  The
                      type-specific cell is undefined.  The
                      interrupt-number is derived from the
                      MPIC a block of registers referred to as
                      the "Interrupt Source Configuration Registers".
                      Each source has 32-bytes of registers
                      (vector/priority and destination) in this
                      region.   So interrupt 0 is at offset 0x0,
                      interrupt 1 is at offset 0x20, and so on.

                  1 = error interrupt
                      The interrupt-number cell contains
                      the SoC device interrupt number for
                      the error interrupt.  The type-specific
                      cell identifies the specific error
                      interrupt number.

                  2 = MPIC inter-processor interrupt (IPI)

                      The interrupt-number cell identifies
                      the MPIC IPI number.  The type-specific
                      cell is undefined.

                  3 = MPIC timer interrupt
                      The interrupt-number cell identifies
                      the MPIC timer number.  The type-specific
                      cell is undefined.

   <4th-cell>   type-specific information

                The type-specific cell is encoded as follows:

                 - For interrupt-type 1 (error interrupt),
                   the type-specific cell contains the
                   bit number of the error interrupt in the

                   Error Interrupt Summary Register.

Please also refer to "Advanced Interrupt Mapping" in  Device Tree Usage - eLinux.org .

Have a great day,
TIC

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