Re: [PATCH net-next v2 10/14] dt-bindings: net: toshiba,tc9654-dwmac: add TC9564 Ethernet bridge

[Alex Elder <elder@riscstar.com>]

On 6/5/26 9:40 AM, Rob Herring wrote:
> On Thu, Jun 04, 2026 at 08:00:17PM -0500, Alex Elder wrote:
>> From: Daniel Thompson <daniel@riscstar.com>
>>
>> Add devicetree bindings for the Toshiba TC956x family of Ethernet-AVB/TSN
>> bridges.
>>
>> The TC9564 contains a PCIe switch with one upstream and three downstream
>> PCIe ports.  The third PCIe downstream port has an attached embedded PCIe
>> endpoint, and that endpoint implements two PCIe functions.  Each internal
>> PCIe function has a Synopsys XGMAC Ethernet interface capable of 10 Gbps
>> operation.
>>
>> The TC9564 also implements an embedded GPIO controller, which exposes
>> 10 lines externally.  Some platforms use these GPIO lines, so this
>> GPIO controller is managed by a separate driver.  Other embedded
>> peripherals (like a microcontroller, SRAM, and UART) are currently
>> unused.
>>
>> The GPIO controller is managed by registers accessed via MMIO on an
>> internal PCIe function's registers.
>>
>> Signed-off-by: Daniel Thompson <daniel@riscstar.com>
>> Signed-off-by: Alex Elder <elder@riscstar.com>
>> ---
>>   .../bindings/net/toshiba,tc9564-dwmac.yaml    | 120 ++++++++++++++++++
>>   MAINTAINERS                                   |   6 +
>>   2 files changed, 126 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/net/toshiba,tc9564-dwmac.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/net/toshiba,tc9564-dwmac.yaml b/Documentation/devicetree/bindings/net/toshiba,tc9564-dwmac.yaml
>> new file mode 100644
>> index 0000000000000..6e7a63dfcf86a
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/net/toshiba,tc9564-dwmac.yaml
>> @@ -0,0 +1,120 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/net/toshiba,tc9564-dwmac.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Toshiba TC956x Ethernet-AVB/TSN Controller
>> +
>> +maintainers:
>> +  - Alex Elder <elder@riscstar.com>
>> +  - Daniel Thompson <daniel@riscstar.com>
>> +
>> +description: |
>> +  The Toshiba TC9564 (and more generally, TC956x) incorporates a PCIe
>> +  gen 3 switch with one upstream and three downstream ports.  The first
>> +  two downstream ports are exposed externally, while the third is used
>> +  by an internal PCIe endpoint.  The PCIe endpoint implements two PCIe
>> +  functions, and attached to each of these is a 10 Gbps capable Synopsys
>> +  Ethernet controller.
>> +
>> +  The TC956x additionally implements other internal IP blocks, and in
>> +  particular it implements a GPIO controller.  Ten of the 35 GPIO lines
>> +  implemented are exposed externally and are usable by the platform.
>> +  It is platform-dependent whether the GPIO function must be exposed,
>> +  and if it is, PCIe function 0 supplies it.
>> +
>> +              ----------------------------------
>> +              |              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 |  ------ |
> 
> I don't see nodes for these PCI functions. Boot this platform with
> CONFIG_PCI_DYNAMIC_OF_NODES enabled and use the resulting DT node
> structure. Anything else is wrong. This will give you the DTS:
> 
> dtc -O dts /proc/device-tree
> 
> The ethernet nodes should be just these PCI function nodes. You need to
> make the DWMAC PCI driver (stmmac_pci.c) bind to those 2 PCI devices.
> And really, a DT node for them should be completely optional (unless
> there's some power on ctrl needed).
> 
> Everything else like SPI, GPIO, UART, etc. should be under the PCIe
> switch upstream node in a pci-ep-bus.

I unfortunately hadn't looked closely enough at pci-ep-bus
before.  It really looks like what we should use.  It's a
simple bus, and we'll use platform drivers and compatible
strings to match the devices on the bus.

I'll work toward converting things over to use this model.

> 
> 
>> +    |  | E |----++----|  |----++----| E |         |
>> +    |  | N |  eMAC 0  |  |  eMAC 1  | N |         |
>> +    --------+.......+------+.....+-----------------
>> +            |USXGMII|      |SGMII|
>> +          --+.......+--  --+.....+--
>> +          |  ARQ113C  |  | QEP8121 |
>> +          |    PHY    |  |   PHY   |
>> +          -------------  -----------
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - pci1179,0220 # Toshiba TC9564 (a.k.a. Qualcomm QPS615)
>> +
>> +  gpio:
>> +    type: object
>> +    description: Embedded GPIO controller
>> +    $ref: /schemas/gpio/gpio.yaml#
> 
> gpio.yaml alone does not define a GPIO controller. How many #gpio-cells
> needs to be defined.
> 
> Is there no address associated with the controller?
> 
>> +
>> +  ethernet:
>> +    type: object
>> +    description: XGMAC Ethernet controller
>> +    $ref: /schemas/net/ethernet-controller.yaml#
>> +    properties:
>> +      mdio:
>> +        $ref: snps,dwmac.yaml#/properties/mdio
> 
> Either all of snps,dwmac.yaml should apply or none of it. Generally, we
> only reference whole schema files (OF graph being a notable exception).

OK.

> 
>> +    required:
>> +      - mdio
>> +
>> +required:
>> +  - compatible
>> +
>> +allOf:
>> +  - $ref: /schemas/pci/pci-device.yaml#
>> +  - $ref: /schemas/pci/pci-bus-common.yaml#
> 
> These 2 are just pci-pci-bridge.yaml.

OK.

					-Alex

> 
> Rob