[PATCH v2 0/5] Add PCIe support to Sophgo SG2042 SoC

Chen Wang
2024-12-09T07:19:35Z

From: Chen Wang <unicorn_wang@outlook.com>

Sophgo's SG2042 SoC uses Cadence PCIe core to implement RC mode.

SG2042 PCIe controller supports two ways to report MSI:

Method A, the PICe controller implements an MSI interrupt controller
inside, and connect to PLIC upward through one interrupt line. Provides
memory-mapped msi address, and by programming the upper 32 bits of the
address to zero, it can be compatible with old pcie devices that only
support 32-bit msi address.

Method B, the PICe controller connects to PLIC upward through an
independent MSI controller "sophgo,sg2042-msi" on the SOC. The MSI
controller provides multiple(up to 32) interrupt sources to PLIC.
Compared with the first method, the advantage is that the interrupt
source is expanded, but because for SG2042, the msi address provided
by the MSI controller is fixed and only supports 64-bit address(> 2^32),
it is not compatible with old pcie devices that only support 32-bit
msi address.

This patchset depends on another patchset for the SG2042 MSI controller[msi].
If you need to test the DTS part, you need to apply the corresponding
patchset.

Link: https://lore.kernel.org/linux-riscv/cover.1733726057.git.unicorn_wang@outlook.com/ [msi]

Thanks,
Chen

---

Changes in v2:
The patch series is based on v6.13-rc2.

Fixed following issues as per comments from Rob Herring, Bjorn Helgaas, thanks.

- Improve driver binding description
- Define a new embeded object property msi to replace the "sophgo,internal-msi".
- Rename "sophgo,link-id" to "sophgo,pcie-port" as per suggestion from Bjorn,
and add more explanaion for this property.
- Use msi-parent.
- Improve driver code:
- Improve coding style.
- Fix a bug and make sure num_applied_vecs updated with the max value.
- Use the MSI parent model.
- Remove .cpu_addr_fixup.
- Reorder Kconfig menu item to keep them in alphabetical order by vendor.

Changes in v1:
The patch series is based on v6.12-rc7. You can simply review or test the
patches at the link [1].

Link: https://lore.kernel.org/linux-riscv/cover.1731303328.git.unicorn_wang@outlook.com/ [1]
---

Chen Wang (5):
dt-bindings: pci: Add Sophgo SG2042 PCIe host
PCI: sg2042: Add Sophgo SG2042 PCIe driver
dt-bindings: mfd: syscon: Add sg2042 pcie ctrl compatible
riscv: sophgo: dts: add pcie controllers for SG2042
riscv: sophgo: dts: enable pcie for PioneerBox

.../devicetree/bindings/mfd/syscon.yaml | 2 +
.../bindings/pci/sophgo,sg2042-pcie-host.yaml | 141 +++++
.../boot/dts/sophgo/sg2042-milkv-pioneer.dts | 12 +
arch/riscv/boot/dts/sophgo/sg2042.dtsi | 89 +++
drivers/pci/controller/cadence/Kconfig | 11 +
drivers/pci/controller/cadence/Makefile | 1 +
drivers/pci/controller/cadence/pcie-sg2042.c | 534 ++++++++++++++++++
7 files changed, 790 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pci/sophgo,sg2042-pcie-host.yaml
create mode 100644 drivers/pci/controller/cadence/pcie-sg2042.c

base-commit: fac04efc5c793dccbd07e2d59af9f90b7fc0dca4
--
2.34.1