Re: [PATCH 1/4] dt-bindings: soc: introduce toshiba,tc9564-config-syscon.yaml

[Krzysztof Kozlowski <krzk@kernel.org>]

On 04/11/2026 01:43, Alex Elder wrote:
> Define the binding for the system controller that implements the clock
> and reset controller functionality present in the Toshiba TC9564 SoC.
> 
> Co-developed-by: Daniel Thompson <daniel@riscstar.com>
> Signed-off-by: Daniel Thompson <daniel@riscstar.com>
> Signed-off-by: Alex Elder <elder@riscstar.com>
> ---
>  .../toshiba/toshiba,tc9564-config-syscon.yaml | 68 +++++++++++++++++++
>  MAINTAINERS                                   |  8 +++
>  include/dt-bindings/soc/toshiba,tc9564.h      | 46 +++++++++++++
>  3 files changed, 122 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/toshiba/toshiba,tc9564-config-syscon.yaml
>  create mode 100644 include/dt-bindings/soc/toshiba,tc9564.h
> 
> diff --git a/Documentation/devicetree/bindings/soc/toshiba/toshiba,tc9564-config-syscon.yaml b/Documentation/devicetree/bindings/soc/toshiba/toshiba,tc9564-config-syscon.yaml
> new file mode 100644
> index 0000000000000..5a241a9c915d1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/toshiba/toshiba,tc9564-config-syscon.yaml
> @@ -0,0 +1,68 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/toshiba/toshiba,tc9564-config-syscon.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Toshiba TC9564 Multifunction System Controller
> +
> +maintainers:
> +  - Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>
> +  - Alex Elder <elder@riscstar.com>
> +  - Daniel Thompson <daniel@riscstar.com>
> +
> +description:
> +  The Toshiba TC9564 is an SoC accessed by a host system through the
> +  upstream PCIe port on the PCIe switch it implements.  The switch
> +  includes an embedded PCIe endpoint that provides access to various
> +  SoC peripherals via its BARs.  These peripherals include a simple
> +  controller to gate internal clocks, as well as a reset controller.
> +
> +  The clock controller uses registers within the same page as a reset
> +  controller, so this system controller controls access to both.
> +
> +  A total of 21 simple gated clocks are implemented within the SoC.
> +  At this time, support for enabling and disabling only a subset of
> +  them is provided at this time.  Similarly, the SoC implements 13
> +  resets, but currently not all of them can be controlled.
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: toshiba,tc9564-config-syscon
> +      - const: syscon
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  "#clock-cells":
> +    const: 1
> +    description:
> +      Clock ids are defined in <include/dt-bindings/soc/toshiba,tc9564.h>
> +
> +  "#reset-cells":
> +    const: 1
> +    description:
> +      Reset ids are defined in <include/dt-bindings/soc/toshiba,tc9564.h>
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - "#clock-cells"
> +  - "#reset-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    syscon@0 {
> +        compatible = "toshiba,tc9564-config-syscon", "syscon";

I disagree this to be syscon.

This is internal to the PCI device. I read Daniel Thompson answer:
https://lore.kernel.org/all/auOI8LbZNWbNGJuN@aspen.lan/
And I accept arguments that you want to re-use a lot of existing
bindings like DWMAC and so on. Syscon does not count there.

I remember you posted somewhere full DTS, but now I could not find it
again and I do not see it in the cover letter here.

So again, why does it have to be a syscon, which is pure
internal-register-access thingy?

Best regards,
Krzysztof