我们得PCIe C3接口接了一个2lane的ASM1806的switch芯片，但是在系统中lspci无法发现设备，下列是相关的日志信息，
同时，我们还有另外一块适配AGX ORIN的载板，也已经适配了Thor模组，Thor 的PCIe C3对应的信号引到了M.2 Key M上， 也识别不到PCIe设备，这个载板使用AGX ORIN的时候，对应的PCIe功能是正常的。所以硬件电路是没有问题的。
[ 7.428573] tegra264-pcie a808440000.pcie: host bridge /bus@0/pcie@a808440000 ranges:
[ 7.436242] tegra264-pcie a808440000.pcie: MEM 0x0038000000..0x003fffffff -> 0x0038000000
[ 7.444971] tegra264-pcie a808440000.pcie: MEM 0xb8c0000000..0xc07fffffff -> 0xb8c0000000
[ 7.462097] tegra264-pcie a808440000.pcie: ECAM at [mem 0xb8b0000000-0xb8bfffffff] for [bus 00-ff]
[ 8.471640] tegra264-pcie a808440000.pcie: PCIe Controller-3 Link is DOWN
[ 8.471716] tegra264-pcie a808440000.pcie: PCI host bridge to bus 0003:00
[ 8.476635] pci_bus 0003:00: root bus resource [mem 0x38000000-0x3fffffff]
[ 8.483615] pci_bus 0003:00: root bus resource [mem 0xb8c0000000-0xc07fffffff pref]
[ 8.491298] pci_bus 0003:00: root bus resource [io 0x600000-0x7fffff] (bus address [0x84000000-0x841fffff])
[ 8.501107] pci 0003:00:00.0: [10de:22da] type 01 class 0x060400 PCIe Root Port
[ 8.508450] pci 0003:00:00.0: PCI bridge to [bus 01-ff]
[ 8.513880] pci 0003:00:00.0: PME# supported from D0 D3hot
[ 8.520659] pci 0003:00:00.0: bridge window [io 0x1000-0x0fff] to [bus 01-ff] add_size 1000
[ 8.527622] pci 0003:00:00.0: bridge window [mem 0x00100000-0x000fffff 64bit pref] to [bus 01-ff] add_size 200000 add_align 100000
[ 8.539491] pci 0003:00:00.0: bridge window [mem 0x00100000-0x000fffff] to [bus 01-ff] add_size 200000 add_align 100000
[ 8.566382] pci 0003:00:00.0: bridge window [io 0x600000-0x600fff]: assignedbit pref]: assigned
[ 8.573718] pci 0003:00:00.0: PCI bridge to [bus 01-ff]
[ 8.578957] pci 0003:00:00.0: bridge window [io 0x600000-0x600fff]
[ 8.585244] pci 0003:00:00.0: bridge window [mem 0x38000000-0x381fffff]
[ 8.592226] pci 0003:00:00.0: bridge window [mem 0xb8c0000000-0xb8c01fffff 64bit pref]
[ 8.600262] pci_bus 0003:00: resource 4 [mem 0x38000000-0x3fffffff]
[ 8.606543] pci_bus 0003:00: resource 5 [mem 0xb8c0000000-0xc07fffffff pref]
[ 8.613528] pci_bus 0003:00: resource 6 [io 0x600000-0x7fffff]
[ 8.619466] pci_bus 0003:01: resource 0 [io 0x600000-0x600fff]
[ 8.625402] pci_bus 0003:01: resource 1 [mem 0x38000000-0x381fffff]
[ 8.631688] pci_bus 0003:01: resource 2 [mem 0xb8c0000000-0xb8c01fffff 64bit pref]
[ 8.641612] pcieport 0003:00:00.0: Adding to iommu group 10
[ 8.645547] pcieport 0003:00:00.0: PME: Signaling with IRQ 195
[ 8.651744] pcieport 0003:00:00.0: AER: enabled with IRQ 182
[ 8.656514] pcieport 0003:00:00.0: pciehp: Slot #0 AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+ Interlock- NoCompl+ IbPresDis- LLActRep+
[ 8.671043] pcieport 0003:00:00.0: pciehp: Slot(0): Card present
[ 8.671433] pcieport 0003:00:00.0: DPC: enabled with IRQ 181
[ 8.681642] pcieport 0003:00:00.0: DPC: error containment capabilities: Int Msg #1, RPExt+ PoisonedTLP+ SwTrigger+ RP PIO Log 4, DL_ActiveErr+
跟PCIE C3控制器相关的内容修改如下：
#y-c28-agx-thor-382.conf文件
#UPHY_CONFIG="tegra264-mb1-bct-uphy-lanes-p4071-0000.dts";
UPHY_CONFIG="";
#BPFDTB_FILE="tegra264-bpmp-3834-0008-4071-xxxx.dtb";
BPFDTB_FILE="tegra264-bpmp-3834-0008-4071-xxxx-c28.dtb";
#PINMUX_CONFIG="tegra264-mb1-bct-pinmux-p3834-xxxx-p4071-0000.dts";
PINMUX_CONFIG="tegra264-mb1-bct-pinmux-p3834-xxxx-p4071-0000-c28.dts";
#DTB_FILE="tegra264-p4071-0000+p3834-0008-nv.dtb";
DTB_FILE="y-c28-agx-thor-382.dtb";
#tegra264-bpmp-3834-0008-4071-xxxx-c28.dts文件
pcie@3 {
//status = "disabled"; /* Modify by chenxi to support y-c28's PCIE */
status = "okay";
pcie-id = <0x03>;
pcie-mode = <0x01>;
max-link-speed = <0x05>;
hot-plug-capable = <1>; /* Add by chenxi */
};
uphy {
status = "okay";
//uphy0-config = <0x07>;
uphy0-config = <0x06>; /* Modify by chenxi to support y-c28 pcie C3 */
#tegra264-mb1-bct-pinmux-p3834-xxxx-p4071-0000-c28.dts文件
pex_l3_clkreq_n_pb4 {
nvidia,pins = "pex_l3_clkreq_n_pb4";
nvidia,function = "pe3_clkreq_l";
nvidia,pull = <TEGRA_PIN_PULL_NONE>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
nvidia,drv-type = <TEGRA_PIN_1X_DRIVER>;
nvidia,e-io-od = <TEGRA_PIN_ENABLE>;
nvidia,e-lpbk = <TEGRA_PIN_DISABLE>;
};
pex_l3_rst_n_pb5 {
nvidia,pins = "pex_l3_rst_n_pb5";
nvidia,function = "pe3_rst_l";
nvidia,pull = <TEGRA_PIN_PULL_NONE>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_DISABLE>;
nvidia,drv-type = <TEGRA_PIN_1X_DRIVER>;
nvidia,e-io-od = <TEGRA_PIN_ENABLE>;
nvidia,e-lpbk = <TEGRA_PIN_DISABLE>;
};
# dtb文件
/* PCIe C3 */
pcie@a808440000 {
status = "okay";
};
