18c2ecf20Sopenharmony_ci# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
28c2ecf20Sopenharmony_ci# Copyright 2019 BayLibre, SAS
38c2ecf20Sopenharmony_ci%YAML 1.2
48c2ecf20Sopenharmony_ci---
58c2ecf20Sopenharmony_ci$id: "http://devicetree.org/schemas/mailbox/amlogic,meson-gxbb-mhu.yaml#"
68c2ecf20Sopenharmony_ci$schema: "http://devicetree.org/meta-schemas/core.yaml#"
78c2ecf20Sopenharmony_ci
88c2ecf20Sopenharmony_cititle: Amlogic Meson Message-Handling-Unit Controller
98c2ecf20Sopenharmony_ci
108c2ecf20Sopenharmony_cimaintainers:
118c2ecf20Sopenharmony_ci  - Neil Armstrong <narmstrong@baylibre.com>
128c2ecf20Sopenharmony_ci
138c2ecf20Sopenharmony_cidescription: |
148c2ecf20Sopenharmony_ci  The Amlogic's Meson SoCs Message-Handling-Unit (MHU) is a mailbox controller
158c2ecf20Sopenharmony_ci  that has 3 independent channels/links to communicate with remote processor(s).
168c2ecf20Sopenharmony_ci  MHU links are hardwired on a platform. A link raises interrupt for any
178c2ecf20Sopenharmony_ci  received data. However, there is no specified way of knowing if the sent
188c2ecf20Sopenharmony_ci  data has been read by the remote. This driver assumes the sender polls
198c2ecf20Sopenharmony_ci  STAT register and the remote clears it after having read the data.
208c2ecf20Sopenharmony_ci
218c2ecf20Sopenharmony_ciproperties:
228c2ecf20Sopenharmony_ci  compatible:
238c2ecf20Sopenharmony_ci    enum:
248c2ecf20Sopenharmony_ci      - amlogic,meson-gxbb-mhu
258c2ecf20Sopenharmony_ci
268c2ecf20Sopenharmony_ci  reg:
278c2ecf20Sopenharmony_ci    maxItems: 1
288c2ecf20Sopenharmony_ci
298c2ecf20Sopenharmony_ci  interrupts:
308c2ecf20Sopenharmony_ci    minItems: 3
318c2ecf20Sopenharmony_ci    description:
328c2ecf20Sopenharmony_ci      Contains the interrupt information corresponding to each of the 3 links
338c2ecf20Sopenharmony_ci      of MHU.
348c2ecf20Sopenharmony_ci
358c2ecf20Sopenharmony_ci  "#mbox-cells":
368c2ecf20Sopenharmony_ci    const: 1
378c2ecf20Sopenharmony_ci
388c2ecf20Sopenharmony_cirequired:
398c2ecf20Sopenharmony_ci  - compatible
408c2ecf20Sopenharmony_ci  - reg
418c2ecf20Sopenharmony_ci  - interrupts
428c2ecf20Sopenharmony_ci  - "#mbox-cells"
438c2ecf20Sopenharmony_ci
448c2ecf20Sopenharmony_ciadditionalProperties: false
458c2ecf20Sopenharmony_ci
468c2ecf20Sopenharmony_ciexamples:
478c2ecf20Sopenharmony_ci  - |
488c2ecf20Sopenharmony_ci    mailbox@c883c404 {
498c2ecf20Sopenharmony_ci          compatible = "amlogic,meson-gxbb-mhu";
508c2ecf20Sopenharmony_ci          reg = <0xc883c404 0x4c>;
518c2ecf20Sopenharmony_ci          interrupts = <208>, <209>, <210>;
528c2ecf20Sopenharmony_ci          #mbox-cells = <1>;
538c2ecf20Sopenharmony_ci    };
548c2ecf20Sopenharmony_ci
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