7.6. Absent and vestigial hardware (reference-base leftovers)

The SM6350 is a smartphone SoC; the shipped device tree and overlays are derived from the Qualcomm lagoon reference design and instantiate whole subsystems this e-reader does not populate. This page catalogues those blocks with the static evidence that they are unwired: a block being in the tree does not mean it exists on the board. This is the same pattern as the XBL AMOLED panel string (Boot image: kernel, DTB, ramdisk, config) and the mmWave/5G RF thermal zones (ADSP and CDSP firmware); this page collects the SoC-fabric cases.

7.6.1. Camera / Titan ISP — present, unpopulated

The full Titan camera pipeline is instantiated in the base tree:

  • ISP / compute blocks: qcom,cam-cpas (CPAS bus/QoS), qcom,cam-isp, qcom,cam-ipe, qcom,cam-bps, qcom,cam-icp, qcom,cam-jpeg, qcom,cam-lrme, qcom,cam-cdm-intf and qcom,cam-req-mgr.

  • Sensor interfaces: two CCI controllers (qcom,cci ×2) and four CSI PHYs (qcom,csiphy-v1.2.3, csiphy0–csiphy3).

  • Clock / power: CAMCC (qcom,lagoon-camcc at 0xAD00000, Clock tree — GCC, domain CCs, RPMh), the TITAN_SS / TITAN_CAM_CC windows in the XBL MMAP, and the PM8008 I²C camera PMIC (qcom,i2c-pmic at USID 8, Pin control — TLMM and the PMIC GPIOs).

  • Pins: four CCI_I2C groups (gpio2/3, 39/40, 41/42, 43/44) and five CAM_MCLK0–4 clocks (gpio29–33) in the TLMM (Pin control — TLMM and the PMIC GPIOs).

  • Overlay wiring: the dtbo overlays even declare four camera modules — qcom,cam-sensor@2/4/5/6 with matching qcom,eeprom@* and qcom,actuator@4/5/6 — a full rear+front reference camera set.

Despite all of that, the Note Air5 C ships no camera. The tree and overlay are the SM6350 reference camera design carried through unchanged; the CCI/MCLK pads and the PM8008 rail are declared but unused. (Verifying that the pads are truly unconnected is a board-inspection question, not a static one, but nothing in the boot chain or the product touches the camera path.)

7.6.2. PCIe — absent

There is no PCIe controller in the tree: zero qcom,pcie / pcie@ / device_type = "pci" nodes. The only trace is a single apps-SMMU translation unit stub, pcie_tbu@1519d000 (Base kernel device tree (the SoC boot contract)) — a leftover SMMU TBU with no root complex behind it. XBL confirms it: in uefiplat.cfg the ## PCIE ## section has #PCIeRPNumber=0x0101 commented out, so no root ports are enabled. PCIe is not present on this device.

7.6.3. HDMI — vestigial audio/bridge stubs

No HDMI connector exists, but the reference tree leaves HDMI stubs:

  • three qcom,msm-dai-q6-hdmi audio DAIs (the Q6 AFE HDMI-audio front ends, ADSP and CDSP firmware), and

  • qcom,msm-hdmi-dba-codec-rx — an HDMI “display-bridge-adapter” codec node.

These are audio/bridge plumbing for an HDMI output the device does not have.

7.6.4. DisplayPort — present SoC block, not the display path

qcom,dp_display@ae90000 (sde_dp) is a real MDSS DisplayPort controller — part of the SoC, capable of DP-alt-mode over USB-C. It is not the device’s display path: the panel is e-ink driven through the DPU and the EPD FPGA (Display pipeline — DSI transport to the color e-ink TCON, Pin control — TLMM and the PMIC GPIOs). Whether DP-alt-mode is exposed on the Type-C port is a board-populate question; the primary and boot-time display is e-ink, and nothing below userspace drives DP.

7.6.5. Where the other leftovers live

For completeness, the vestigial items documented elsewhere:

7.6.6. Provenance

Source:

artifacts/boot_a/board.dts (camera qcom,cam-* / qcom,cci / qcom,csiphy nodes, absence of PCIe controller nodes, pcie_tbu stub, HDMI DAIs / DBA codec, dp_display@ae90000), artifacts/dtbo_a/overlay_0.dts (declared cam-sensor / eeprom / actuator modules), _READONLY/lun1/xbl_a.bin (uefiplat.cfg ## PCIE ## commented PCIeRPNumber, TITAN_* MMAP windows).

Method:

DTB node census + presence/absence check + XBL config carve. No code executed.

Cross-refs:

Pin control — TLMM and the PMIC GPIOs (CCI/MCLK pins, PM8008), Clock tree — GCC, domain CCs, RPMh (CAMCC), Base kernel device tree (the SoC boot contract) (pcie_tbu SMMU stub), Display pipeline — DSI transport to the color e-ink TCON (the real display path), ADSP and CDSP firmware (RF/HDMI-audio leftovers), Boot image: kernel, DTB, ramdisk, config (AMOLED reference leftover).