xref: /linux/Documentation/devicetree/bindings/mailbox/cix,sky1-mbox.yaml (revision 4df9c0a2465a523e399e46a8d3b5866c769b381b)
1*621d7d08SGuomin Chen# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2*621d7d08SGuomin Chen%YAML 1.2
3*621d7d08SGuomin Chen---
4*621d7d08SGuomin Chen$id: http://devicetree.org/schemas/mailbox/cix,sky1-mbox.yaml#
5*621d7d08SGuomin Chen$schema: http://devicetree.org/meta-schemas/core.yaml#
6*621d7d08SGuomin Chen
7*621d7d08SGuomin Chentitle: Cixtech mailbox controller
8*621d7d08SGuomin Chen
9*621d7d08SGuomin Chenmaintainers:
10*621d7d08SGuomin Chen  - Guomin Chen <Guomin.Chen@cixtech.com>
11*621d7d08SGuomin Chen
12*621d7d08SGuomin Chendescription:
13*621d7d08SGuomin Chen  The Cixtech mailbox controller, used in the Cixtech Sky1 SoC,
14*621d7d08SGuomin Chen  is used for message transmission between multiple processors
15*621d7d08SGuomin Chen  within the SoC, such as the AP, PM, audio DSP, SensorHub MCU,
16*621d7d08SGuomin Chen  and others
17*621d7d08SGuomin Chen
18*621d7d08SGuomin Chen  Each Cixtech mailbox controller is unidirectional, so they are
19*621d7d08SGuomin Chen  typically used in pairs-one for receiving and one for transmitting.
20*621d7d08SGuomin Chen
21*621d7d08SGuomin Chen  Each Cixtech mailbox supports 11 channels with different transmission modes
22*621d7d08SGuomin Chen    channel 0-7 - Fast channel with 32bit transmit register and IRQ support
23*621d7d08SGuomin Chen    channel 8   - Doorbell mode,using the mailbox as an interrupt-generating
24*621d7d08SGuomin Chen                   mechanism.
25*621d7d08SGuomin Chen    channel 9   - Fifo based channel with 32*32bit depth fifo and IRQ support
26*621d7d08SGuomin Chen    channel 10  - Reg based channel with 32*32bit transmit register and
27*621d7d08SGuomin Chen                   Doorbell+transmit acknowledgment IRQ support
28*621d7d08SGuomin Chen
29*621d7d08SGuomin Chen  In the CIX Sky1 SoC use case, there are 4 pairs of mailbox controllers
30*621d7d08SGuomin Chen    AP <--> PM - using Doorbell transfer mode
31*621d7d08SGuomin Chen    AP <--> SE - using REG transfer mode
32*621d7d08SGuomin Chen    AP <--> DSP - using FIFO transfer mode
33*621d7d08SGuomin Chen    AP <--> SensorHub - using FIFO transfer mode
34*621d7d08SGuomin Chen
35*621d7d08SGuomin Chenproperties:
36*621d7d08SGuomin Chen  compatible:
37*621d7d08SGuomin Chen    const: cix,sky1-mbox
38*621d7d08SGuomin Chen
39*621d7d08SGuomin Chen  reg:
40*621d7d08SGuomin Chen    maxItems: 1
41*621d7d08SGuomin Chen
42*621d7d08SGuomin Chen  interrupts:
43*621d7d08SGuomin Chen    maxItems: 1
44*621d7d08SGuomin Chen
45*621d7d08SGuomin Chen  "#mbox-cells":
46*621d7d08SGuomin Chen    const: 1
47*621d7d08SGuomin Chen
48*621d7d08SGuomin Chen  cix,mbox-dir:
49*621d7d08SGuomin Chen    $ref: /schemas/types.yaml#/definitions/string
50*621d7d08SGuomin Chen    description: Direction of the mailbox relative to the AP
51*621d7d08SGuomin Chen    enum: [tx, rx]
52*621d7d08SGuomin Chen
53*621d7d08SGuomin Chenrequired:
54*621d7d08SGuomin Chen  - compatible
55*621d7d08SGuomin Chen  - reg
56*621d7d08SGuomin Chen  - interrupts
57*621d7d08SGuomin Chen  - "#mbox-cells"
58*621d7d08SGuomin Chen  - cix,mbox-dir
59*621d7d08SGuomin Chen
60*621d7d08SGuomin ChenadditionalProperties: false
61*621d7d08SGuomin Chen
62*621d7d08SGuomin Chenexamples:
63*621d7d08SGuomin Chen  - |
64*621d7d08SGuomin Chen    #include <dt-bindings/interrupt-controller/arm-gic.h>
65*621d7d08SGuomin Chen
66*621d7d08SGuomin Chen    soc {
67*621d7d08SGuomin Chen        #address-cells = <2>;
68*621d7d08SGuomin Chen        #size-cells = <2>;
69*621d7d08SGuomin Chen
70*621d7d08SGuomin Chen        mbox_ap2pm: mailbox@30000000 {
71*621d7d08SGuomin Chen            compatible = "cix,sky1-mbox";
72*621d7d08SGuomin Chen            reg = <0 0x30000000 0 0x10000>;
73*621d7d08SGuomin Chen            interrupts = <GIC_SPI 136 IRQ_TYPE_LEVEL_HIGH 0>;
74*621d7d08SGuomin Chen            #mbox-cells = <1>;
75*621d7d08SGuomin Chen            cix,mbox-dir = "tx";
76*621d7d08SGuomin Chen        };
77*621d7d08SGuomin Chen    };
78