Re: [PATCH v4] dt-bindings: arm: keystone: add boot_* mboxes to ti,sci

[Nishanth Menon <nm@ti.com>]

On 11:45-20251205, Anshul Dalal wrote:
> The bootloader on K3 devices makes use of mailboxes as per the ROM spec
> which might be different than one's available to the kernel (firmware
> spec).
> 
> Therefore, this patch adds the missing mailbox entries to the DT binding
> if the matching compatible is ti,am654-sci to represent the mailboxes
> exposed by the hardware during boot for the purpose of loading the
> firmware.
> 
> Signed-off-by: Anshul Dalal <anshuld@ti.com>
> ---
> Changes in v4:
> - Make new boot_* mboxes conditional on ti,am654-sci compatible
> - Link to v3: https://lore.kernel.org/r/20251112-k3_syscon_add_boot_mailboxes-v3-1-66155a4236dc@ti.com
> 
> Changes in v3:
> - Drop [1/2] of the last patch series
> - Update existing example with boot_* mailboxes instead of adding a new one
> - Link to v2: https://lore.kernel.org/r/20251112-k3_syscon_add_boot_mailboxes-v2-0-aebc1e47b391@ti.com
> 
> Changes in v2:
> - Remove maxItems entry
> - Remove RFC tag from patch (added by mistake in v1)
> - Document the new mailboxes in mboxes instead of mbox-names
> - Provide example with all the mailboxes set
> - Update commit title to have "ti,sci"
> - Split into two patches
> - Link to v1: https://lore.kernel.org/r/20251111-k3_syscon_add_boot_mailboxes-v1-1-529a27f21076@ti.com
> ---
>  .../devicetree/bindings/arm/keystone/ti,sci.yaml   | 50 +++++++++++++++++++---
>  1 file changed, 43 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml b/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
> index 25a2b42105e5..d9eb2a81e539 100644
> --- a/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
> +++ b/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
> @@ -51,15 +51,15 @@ properties:
>      minItems: 1
>  
>    mbox-names:
> +    minItems: 2
> +    maxItems: 6
>      description: |
>        Specifies the mailboxes used to communicate with TI-SCI Controller
>        made available from TI-SCI controller.
> -    items:
> -      - const: rx
> -      - const: tx
>  
>    mboxes:
>      minItems: 2
> +    maxItems: 6
>  
>    ti,host-id:
>      $ref: /schemas/types.yaml#/definitions/uint32
> @@ -79,6 +79,42 @@ properties:
>      type: object
>      $ref: /schemas/reset/ti,sci-reset.yaml#
>  
> +if:
> +  properties:
> +    compatible:
> +      contains:
> +        const: ti,am654-sci
> +then:
> +  properties:
> +    mbox-names:
> +      minItems: 2
> +      items:
> +        - const: rx
> +        - const: tx
> +        - const: notify
> +        - const: boot_rx
> +        - const: boot_tx
> +        - const: boot_notify
> +    mboxes:
> +      minItems: 2
> +      items:
> +        - description: RX thread
> +        - description: TX thread
> +        - description: Notify thread
> +        - description: boot stage RX thread
> +        - description: boot stage TX thread
> +        - description: boot stage Notify thread
> +else:
> +  properties:
> +    mbox-names:
> +      items:
> +        - const: rx
> +        - const: tx
> +    mboxes:
> +      items:
> +        - description: RX thread
> +        - description: TX thread
> +
>  required:
>    - compatible
>    - mbox-names
> @@ -99,11 +135,11 @@ examples:
>  
>    - |
>      dmsc: system-controller@44083000 {
> -      compatible = "ti,k2g-sci";
> +      compatible = "ti,am654-sci";
>        ti,host-id = <12>;
> -      mbox-names = "rx", "tx";
> -      mboxes = <&secure_proxy_main 11>,
> -               <&secure_proxy_main 13>;
> +      mbox-names = "rx", "tx", "notify", "boot_rx", "boot_tx";
> +      mboxes= <&secure_proxy_mcu 6>, <&secure_proxy_mcu 8>,
> +        <&secure_proxy_mcu 5>, <&secure_proxy_mcu 5>, <&secure_proxy_mcu 4>;
>        reg-names = "debug_messages";
>        reg = <0x44083000 0x1000>;

Create another example. why are we dropping k2g-sci - that is still
valid and the schema must continue to support - so functions as a
validation.

However, i'd like to make sure this can handle two different patterns -
example: AM62x and j784s4.

>  
> 
> ---
> base-commit: 4427259cc7f7571a157fbc9b5011e1ef6fe0a4a8
> change-id: 20251105-k3_syscon_add_boot_mailboxes-8452bdd98962
> 
> Best regards,
> -- 
> Anshul Dalal <anshuld@ti.com>
> 

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D
https://ti.com/opensource