[PATCH v12 3/8] dt-bindings: arm: Document reboot mode magic

Shivendra Pratap
2025-07-21T18:29:32Z

From: Elliot Berman <elliot.berman@oss.qualcomm.com>

Add bindings to describe vendor-specific reboot modes. Values here
correspond to valid parameters to vendor-specific reset types in PSCI
SYSTEM_RESET2 call.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Elliot Berman <elliot.berman@oss.qualcomm.com>
Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
Documentation/devicetree/bindings/arm/psci.yaml | 43 +++++++++++++++++++++++++
1 file changed, 43 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/psci.yaml b/Documentation/devicetree/bindings/arm/psci.yaml
index 7360a2849b5bd1e4cbadac533c1a7228573288d4..da3a584c76b48e313a5d4cb7c8e0c3a3628fd1bb 100644
--- a/Documentation/devicetree/bindings/arm/psci.yaml
+++ b/Documentation/devicetree/bindings/arm/psci.yaml
@@ -98,6 +98,27 @@ properties:
[1] Kernel documentation - ARM idle states bindings
Documentation/devicetree/bindings/cpu/idle-states.yaml

+ reboot-mode:
+ type: object
+ $ref: /schemas/power/reset/reboot-mode.yaml#
+ unevaluatedProperties: false
+ properties:
+ # "mode-normal" is just SYSTEM_RESET
+ mode-normal: false
+ patternProperties:
+ "^mode-.*$":
+ minItems: 1
+ maxItems: 2
+ description: |
+ Describes a vendor-specific reset type. The string after "mode-"
+ maps a reboot mode to the parameters in the PSCI SYSTEM_RESET2 call.
+
+ Parameters are named mode-xxx = <type[, cookie]>, where xxx
+ is the name of the magic reboot mode, type is the lower 31 bits
+ of the reset_type, and, optionally, the cookie value. If the cookie
+ is not provided, it is defaulted to zero.
+ The 31st bit (vendor-resets) will be implicitly set by the driver.
+
patternProperties:
"^power-domain-":
$ref: /schemas/power/power-domain.yaml#
@@ -137,6 +158,15 @@ allOf:
required:
- cpu_off
- cpu_on
+ - if:
+ not:
+ properties:
+ compatible:
+ contains:
+ const: arm,psci-1.0
+ then:
+ properties:
+ reset-types: false

additionalProperties: false

@@ -261,4 +291,17 @@ examples:
domain-idle-states = <&cluster_ret>, <&cluster_pwrdn>;
};
};
+
+ - |+
+
+ // Case 5: SYSTEM_RESET2 vendor resets
+ psci {
+ compatible = "arm,psci-1.0";
+ method = "smc";
+
+ reboot-mode {
+ mode-edl = <0>;
+ mode-bootloader = <1 2>;
+ };
+ };
...

--
2.34.1