[PATCH v3 0/7] Add PCIe support to Sophgo SG2042 SoC

[Chen Wang]

Hello, Bjorn,

Is it ok for you to pick this patchset, so we can see this in next 6.18.

You can pick [1/7]~[3/7], I can handle the left dts part.

Thanks,

Chen

On 9/12/2025 10:35 AM, Chen Wang wrote:
> From: Chen Wang <unicorn_wang at outlook.com>
>
> Sophgo's SG2042 SoC uses Cadence PCIe core to implement RC mode.
>
> This is a completely rewritten PCIe driver for SG2042. It inherits
> some previously submitted patch codes (not merged into the upstream
> mainline), but the biggest difference is that the support for
> compatibility with old 32-bit PCIe devices has been removed in this
> new version. This is because after discussing with community users,
> we felt that there was not much demand for support for old devices,
> so we made a new design based on the simplified design and practical
> needs. If someone really needs to play with old devices, we can provide
> them with some necessary hack patches in the downstream repository.
>
> Since the new design is quite different from the old code, I will
> release it as a new patch series. The old patch series can be found in
> here [old-series].
>
> Note, regarding [2/7] of this patchset, this fix is introduced because
> the pcie->ops pointer is not filled in SG2042 PCIe driver. This is not
> a must-have parameter, if we use it w/o checking will cause a null
> pointer access error during runtime.
>
> Link: https://lore.kernel.org/linux-riscv/cover.1736923025.git.unicorn_wang@outlook.com/ [old-series]
>
> Thanks,
> Chen
>
> ---
>
> Changes in v3:
>
>    This patchset is based on v6.17-rc1.
>
>    Fixed following issues for driver code based on feedbacks from Bjorn Helgaas,
>    Mingcong Bai, thanks.
>
>    - Fixed the issue when building the driver as a module. Define own pm_ops
>      inside driver, don't use the ops defined in other built-in drivers.
>    - Improve .remove() function to properly disable the host.
>
> Changes in v2:
>
>    This patchset is based on v6.17-rc1. You can simply review or test the
>    patches at the link [2].
>
>    Fixed following issues based on feedbacks from Rob Herring, Manivannan Sadhasivam,
>    Bjorn Helgaas, ALOK TIWARI, thanks.
>
>    - Driver binding:
>      - Removed vendor-id/device-id from "required" property.
>    - Improve drivers code:
>      - Have separated pci_ops for the root bus and child buses.
>      - Make the driver tristate and as a module.
>      - Change the configuration name from PCIE_SG2042 to PCIE_SG2042_HOST.
>      - Removed "Fixes" tag from commit [2/7], since this is not for an existing bug fix.
>      - Other code cleanups and optimizations
>    - DT:
>      - Add PCIe support for SG2042 EVB boards.
>
> Changes in v1:
>
>    The patch series is based on v6.17-rc1. You can simply review or test the
>    patches at the link [1].
>
> Link: https://lore.kernel.org/linux-riscv/cover.1756344464.git.unicorn_wang@outlook.com/ [1]
> Link: https://lore.kernel.org/linux-riscv/cover.1757467895.git.unicorn_wang@outlook.com/ [2]
>
> ---
>
> Chen Wang (7):
>    dt-bindings: pci: Add Sophgo SG2042 PCIe host
>    PCI: cadence: Check pcie-ops before using it
>    PCI: sg2042: Add Sophgo SG2042 PCIe driver
>    riscv: sophgo: dts: add PCIe controllers for SG2042
>    riscv: sophgo: dts: enable PCIe for PioneerBox
>    riscv: sophgo: dts: enable PCIe for SG2042_EVB_V1.X
>    riscv: sophgo: dts: enable PCIe for SG2042_EVB_V2.0
>
>   .../bindings/pci/sophgo,sg2042-pcie-host.yaml |  64 ++++++++
>   arch/riscv/boot/dts/sophgo/sg2042-evb-v1.dts  |  12 ++
>   arch/riscv/boot/dts/sophgo/sg2042-evb-v2.dts  |  12 ++
>   .../boot/dts/sophgo/sg2042-milkv-pioneer.dts  |  12 ++
>   arch/riscv/boot/dts/sophgo/sg2042.dtsi        |  88 +++++++++++
>   drivers/pci/controller/cadence/Kconfig        |  10 ++
>   drivers/pci/controller/cadence/Makefile       |   1 +
>   .../controller/cadence/pcie-cadence-host.c    |   2 +-
>   drivers/pci/controller/cadence/pcie-cadence.c |   4 +-
>   drivers/pci/controller/cadence/pcie-cadence.h |   6 +-
>   drivers/pci/controller/cadence/pcie-sg2042.c  | 138 ++++++++++++++++++
>   11 files changed, 343 insertions(+), 6 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/pci/sophgo,sg2042-pcie-host.yaml
>   create mode 100644 drivers/pci/controller/cadence/pcie-sg2042.c
>
>
> base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585