Re: [PATCH v3 1/2] dt-bindings: firmware: google,gs101-acpm-ipc: document Exynos850 compatible

[Sam Protsenko]

On Mon, Sep 28, 2026 at 9:11 PM Alexey Klimov <alexey.klimov@xxxxxxxxxx> wrote:
>
> The Exynos850 SoC incorporates an APM co-processor. Communication with this
> hardware block is done using the ACPM protocol, which handles IPC messages
> for clocks, power, thermal management and PMIC control. In this
> architecture, the ACPM firmware running on the APM acts as the central
> supervisor or arbiter for shared system resources, handling requests from
> clients or agents such as an OSPM. In this design, the OSPM is one of
> several clients or agents communicating with APM.
>
> Dedicated compatible string is required for the Exynos850 because
> its firmware utilizes a different initialisation data base offset
> (0x7000) compared to the existing GS101 implementation (0xa000).
>
> Additionally, the ACPM firmware implementation on Exynos850 does not cover
> all clock management operations (such as clock rate reads over ACPM IPC).
> To allow the OSPM to resolve rates for these ACPM clock IDs or sometimes
> called domains, add 'clocks' and 'clock-names' properties to reference the
> underlying physical clocks.
>
> Add the "samsung,exynos850-acpm-ipc" compatible string, binding defines for
> Exynos850 ACPM clock IDs, clock property constraints, and disallow GS101-
> specific PMIC child nodes for Exynos850.
>
> Signed-off-by: Alexey Klimov <alexey.klimov@xxxxxxxxxx>
> ---

Reviewed-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>

>  .../bindings/firmware/google,gs101-acpm-ipc.yaml   | 56 +++++++++++++++++++++-
>  include/dt-bindings/clock/samsung,exynos850-acpm.h | 21 ++++++++
>  2 files changed, 76 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/firmware/google,gs101-acpm-ipc.yaml b/Documentation/devicetree/bindings/firmware/google,gs101-acpm-ipc.yaml
> index e68f9c3ca5e2..0eaa9c881f6f 100644
> --- a/Documentation/devicetree/bindings/firmware/google,gs101-acpm-ipc.yaml
> +++ b/Documentation/devicetree/bindings/firmware/google,gs101-acpm-ipc.yaml
> @@ -22,7 +22,9 @@ description: |
>
>  properties:
>    compatible:
> -    const: google,gs101-acpm-ipc
> +    enum:
> +      - google,gs101-acpm-ipc
> +      - samsung,exynos850-acpm-ipc
>
>    "#clock-cells":
>      const: 1
> @@ -33,6 +35,20 @@ properties:
>        appropriately with the clock scaling. The argument is the ID of the
>        clock contained by the firmware messages.
>
> +  clocks:
> +    minItems: 1
> +    maxItems: 9
> +    description:
> +      List of the underlying clocks associated with each ACPM clock domain.
> +      This property relates to ACPM firmware variants where not all clock
> +      operations are implemented.
> +
> +  clock-names:
> +    minItems: 1
> +    maxItems: 9
> +    description:
> +      Names of the ACPM clock domains corresponding to entries in 'clocks'.
> +
>    mboxes:
>      maxItems: 1
>
> @@ -77,6 +93,44 @@ required:
>    - mboxes
>    - shmem
>
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: google,gs101-acpm-ipc
> +    then:
> +      properties:
> +        clocks: false
> +        clock-names: false
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: samsung,exynos850-acpm-ipc
> +    then:
> +      properties:
> +        clock-names:
> +          items:
> +            enum:
> +              - mif
> +              - int
> +              - cpucl0
> +              - cpucl1
> +              - g3d
> +              - aud
> +              - cam
> +              - disp
> +              - cp
> +          uniqueItems: true
> +        pmic: false
> +        pmic-1: false
> +        pmic-2: false
> +      required:
> +        - clocks
> +        - clock-names
> +
>  additionalProperties: false
>
>  examples:
> diff --git a/include/dt-bindings/clock/samsung,exynos850-acpm.h b/include/dt-bindings/clock/samsung,exynos850-acpm.h
> new file mode 100644
> index 000000000000..87fc6ccc1d99
> --- /dev/null
> +++ b/include/dt-bindings/clock/samsung,exynos850-acpm.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
> +/*
> + * Copyright 2026 Linaro Ltd.
> + *
> + * Device Tree binding constants for Exynos850 ACPM clock controller.
> + */
> +
> +#ifndef _DT_BINDINGS_CLOCK_SAMSUNG_EXYNOS850_ACPM_H
> +#define _DT_BINDINGS_CLOCK_SAMSUNG_EXYNOS850_ACPM_H
> +
> +#define EXYNOS850_CLK_ACPM_DVFS_MIF                    0
> +#define EXYNOS850_CLK_ACPM_DVFS_INT                    1
> +#define EXYNOS850_CLK_ACPM_DVFS_CPUCL0                 2
> +#define EXYNOS850_CLK_ACPM_DVFS_CPUCL1                 3
> +#define EXYNOS850_CLK_ACPM_DVFS_G3D                    4
> +#define EXYNOS850_CLK_ACPM_DVFS_AUD                    5
> +#define EXYNOS850_CLK_ACPM_DVFS_CAM                    6
> +#define EXYNOS850_CLK_ACPM_DVFS_DISP                   7
> +#define EXYNOS850_CLK_ACPM_DVFS_CP                     8
> +
> +#endif /* _DT_BINDINGS_CLOCK_SAMSUNG_EXYNOS850_ACPM_H */
>
> --
> 2.51.0
>