[PATCH net-next 00/12] net: enable TC956x support

Alex Elder
2026-05-01T15:54:28Z

This series introduces stmmac driver support for the Toshiba TC9564
(also known as Qualcomm QPS615). This is an Ethernet-AVB/TSN bridge IC
that provides a high-speed connection between a host SoC and Ethernet
devices on a network. It incorporates a PCIe switch, and implements
two 10 Gbps capable Ethernet MACs (along with other IP blocks), and
is essentially a small and highly-specialized SoC. The TC9564 is a
member of a family of similar chips, and the driver code uses "tc956x"
to reflect this.

TC956x chips incorporate a PCIe gen 3 switch, with one upstream and
three downstream ports. Its PCIe functionality is already supported
upstream, including a power control driver that performs some early
configuration of the PCI ports ("pci-pwrctrl-tc9563.c").

One of the PCIe switch's downstream ports has an internal PCIe endpoint,
which implements two PCIe functions, each of which has an Ethernet MAC
(eMAC) subsystem. The eMAC is composed of a Synopsis Designware XGMAC
combined with an XPCS and PMA. Each MAC is capable of operating at
10M/100M/1G/2.5G/5Gps and 10Gps. The initial target platform is the
Qualcomm RB3gen2, which supports a 10Gbps Marvell PHY on port A, and
a 2.5Gbps Qualcomm PHY on port B. (The Marvell PHY is not populated on
all RB3gen2 boards, and only 2.5 Gbps support is included initially.)

TC956x chips also implement several other blocks of functionality,
including a GPIO controller, interrupt controllers (MSIGEN), I2C
and SPI, a UART, and an Arm Cortex M3 CPU with 128KB SRAM. The GPIO
interface exposes several lines to manage external resets. The
interrupt controllers are used internally by the MAC functions. The
UART, SPI, microcontroller, and SRAM are currently unused.

----------------------------------
| Host |
------+...+----------+........+---
|i2c| | PCIe |
----------------+...+----------+........+------
| TC956x |I2C| |upstream| |
| ----- --+--------+--- |
| ----- ------ ------- | PCIe switch | |
| |SPI| |GPIO| |reset| | | |
| ----- ------ |clock| | DS3 DS2 DS1 | |
| ------- ---++--++--++-- |
| ----- ------ downstream// \\ \\ | downstream
| |MCU| |SRAM| /==========/ \\ \===== PCIe port 1
| ----- ------ //PCIe port 3 \\ |
| || \======= downstream
| ----+-----------++-----------+---- | PCIe port 2
| | M | internal PCIe endpoint | M | |
| | S |------------------------| S | ------ |
| | I | PCIe | | PCIe | I | |UART| |
| | G |function 0| |function 1| G | ------ |
| | E |----++----| |----++----| E | |
| | N | eMAC 0 | | eMAC 1 | N | |
--------+.......+------+.....+-----------------
|USXGMII| |SGMII|
--+.......+-- --+.....+--
| ARQ113C | | QEP8121 |
| PHY | | PHY |
------------- -----------

The primary objective for this series is to support the Ethernet
functionality provided by the TC956x. The code providing this
support has been structured into three distinct modules.
- A driver for the GPIO controller
- Code enabling the TC956x-specific eMAC/MSIGEN hardware
- A "chip" driver, associated with the PCIe functions

The GPIO driver is implemented separately because in some hardware
configurations, these GPIO lines are used to manage resets for
external Ethernet PHYs. We describe these PHYs via devicetree,
where the GPIO-based reset signals are defined using phandles.

The code for the eMAC/MSIGEN consists of a new source file that
populates hardware-specific details about the two MACs, and integrates
with the existing stmmac driver. This also required implementing some
enhancements to the core stmmac driver, described further below.

To manage the common functionality (including configuring address
translation and controlling internal reset and clock signals), a
"chip" driver is implemented. This chip driver is associated with
the PCIe function *itself*, not the eMAC associated with the function.

The driver binds to the internal PCI functions 0 and 1, and creates
a shared data structure describing the common chip elements the two
driver instances share. Three auxiliary bus devices are created to
represent the GPIO controller and the two Synopsys MAC controllers.

The driver instance for PCIe function 0 has responsibility for
controlling the common chip functionality--creating the GPIO
controller auxiliary device, configuring address translation
between PCIe address space and internal addresses, and controlling
clocks and resets. It creates a data structure--shared via its
platform data pointer with PCIe function 1--to represent shared
"chip" information. In addition, PCIe function 0 creates an
auxiliary device to represent its attached eMAC. It allocates
IRQs and maps BAR address ranges for use by the stmmac driver,
passing them in a structure via the auxiliary device's platform
data.

PCIe function 1 defers probing until after PCIe function 0 has
created the shared data structure. After that its only job is
to set up IRQs and mapped memory and create the eMAC1 auxiliary
device.

The version of the Synopsys MAC IP is 3.01, which is largely compatible
with version 2.20. The core stmmac driver required several changes to
enable support for the TC956x.
- A change to dwxgmac2 support changes the interrupt mode when
multi_msi_en is enabled.
- While most support for version 3.01 simply uses the 2.20 code,
an erratum related to the RX ring length is implemented for
3.01 DMA operations.
- Having the PCIe device be separate from an auxiliarly device
implementing the eMAC required allowing a distinct DMA device
to be maintained for an stmmac interface.

In addition:
- A new source file provides memory-mapped access to XPCS using
regmap. The alignment of the TC956x MDIO registers aren't
suitable for using simple MMIO.
- Two additional XPCS changes are implemented that provides
support for the XPCS as implemented in the TC956x.

This series is available here:
https://github.com/riscstar/linux/tree/tc956x/stmmac-v1

-Alex (and Daniel)

Alex Elder (3):
net: stmmac: dma: create a separate dma_device pointer
gpio: tc956x: add TC956x/QPS615 support
misc: tc956x_pci: add TC956x/QPS615 support

Daniel Thompson (9):
net: pcs: pcs-xpcs-regmap: support XPCS memory-mapped MDIO bus via
regmap
net: pcs: pcs-xpcs: select operating mode for 10G-baseR capable PCS
net: pcs: pcs-xpcs: Preserve BMCR_ANENBLE during link up
net: stmmac: dwxgmac2: Add multi MSI interrupt mode
net: stmmac: dwxgmac2: Add XGMAC 3.01a support
net: stmmac: dwxgmac2: export symbols for XGMAC 3.01a DMA
dt-bindings: net: toshiba,tc965x-dwmac: add TC956x Ethernet bridge
net: stmmac: tc956x: add TC956x/QPS615 support
arm64: dts: qcom: qcs6490-rb3gen2: enable TC9564 with a single QCS8081
phy

.../bindings/net/toshiba,tc956x-dwmac.yaml | 111 +++
arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 45 +-
drivers/gpio/Kconfig | 11 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-tc956x.c | 209 +++++
drivers/misc/Kconfig | 10 +
drivers/misc/Makefile | 1 +
drivers/misc/tc956x_pci.c | 667 +++++++++++++++
drivers/net/ethernet/stmicro/stmmac/Kconfig | 13 +
drivers/net/ethernet/stmicro/stmmac/Makefile | 2 +
.../net/ethernet/stmicro/stmmac/chain_mode.c | 12 +-
.../ethernet/stmicro/stmmac/dwmac-tc956x.c | 791 ++++++++++++++++++
.../net/ethernet/stmicro/stmmac/dwxgmac2.h | 12 +
.../ethernet/stmicro/stmmac/dwxgmac2_core.c | 1 +
.../ethernet/stmicro/stmmac/dwxgmac2_descs.c | 1 +
.../ethernet/stmicro/stmmac/dwxgmac2_dma.c | 78 +-
.../net/ethernet/stmicro/stmmac/ring_mode.c | 12 +-
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 +
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 59 +-
.../net/ethernet/stmicro/stmmac/stmmac_xdp.c | 2 +-
drivers/net/pcs/Makefile | 4 +-
drivers/net/pcs/pcs-xpcs-regmap.c | 203 +++++
drivers/net/pcs/pcs-xpcs.c | 43 +-
include/linux/pcs/pcs-xpcs-regmap.h | 20 +
include/linux/stmmac.h | 1 +
include/soc/toshiba/tc956x-dwmac.h | 84 ++
26 files changed, 2341 insertions(+), 53 deletions(-)
create mode 100644 Documentation/devicetree/bindings/net/toshiba,tc956x-dwmac.yaml
create mode 100644 drivers/gpio/gpio-tc956x.c
create mode 100644 drivers/misc/tc956x_pci.c
create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-tc956x.c
create mode 100644 drivers/net/pcs/pcs-xpcs-regmap.c
create mode 100644 include/linux/pcs/pcs-xpcs-regmap.h
create mode 100644 include/soc/toshiba/tc956x-dwmac.h

base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
--
2.51.0