bindings/mailbox/arm%2Cmhuv2.yaml

1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
3 ---
4 $id: http://devicetree.org/schemas/mailbox/arm,mhuv2.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
7 title: ARM MHUv2 Mailbox Controller
10   - Tushar Khandelwal <tushar.khandelwal@arm.com>
11   - Viresh Kumar <viresh.kumar@linaro.org>
15   between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
19   Given the unidirectional nature of the controller, an MHUv2 mailbox may only
28   protocols. The transport protocols determine the method of data transmission
31   Following are the possible transport protocols.
33   - Data-transfer: Each transfer is made of one or more words, using one or more
36   - Doorbell: Each transfer is made up of single bit flag, using any one of the
49           - arm,mhuv2-tx
50           - arm,mhuv2-rx
52     - compatible
57       - description: Sender mode
59           - const: arm,mhuv2-tx
60           - const: arm,primecell
62       - description: Receiver-mode
64           - const: arm,mhuv2-rx
65           - const: arm,primecell
72       The MHUv2 controller always implements an interrupt in the "receiver"
74       version MHUv2.0, but the later versions do have it.
80   clock-names:
83   arm,mhuv2-protocols:
84     $ref: /schemas/types.yaml#/definitions/uint32-matrix
86       The MHUv2 controller may contain up to 124 channel windows (each 32-bit
88       be used for various transport protocols.
91       used in various transport protocols. The entries in this property shall be
97       for doorbell protocol, and 1 is reserved for data-transfer protocol.
102       doorbell protocol this field signifies the number of 32-bit channel
103       windows that implement the doorbell protocol. For data-transfer protocol,
104       this field signifies the number of 32-bit channel windows that implement
105       the data-transfer protocol.
114           arm,mhuv2-protocols = <0 2>, <1 1>, <1 5>, <1 7>;
117       The above example defines the protocols of an ARM MHUv2 mailbox
120       7 windows (separately) used in data-transfer protocol.
126         - enum: [ 0, 1 ]
127         - minimum: 0
131   '#mbox-cells':
135       doorbell, or data-transfer protocol, and the second argument (only
139       From the example given above for arm,mhuv2-protocols, here is how a client
155         const: arm,mhuv2-rx
158     - interrupts
161   - compatible
162   - reg
163   - '#mbox-cells'
164   - arm,mhuv2-protocols
169   # Multiple transport protocols implemented by the mailbox controllers
170   - |
172         #address-cells = <2>;
173         #size-cells = <2>;
176             #mbox-cells = <2>;
177             compatible = "arm,mhuv2-tx", "arm,primecell";
180             clock-names = "apb_pclk";
182             arm,mhuv2-protocols = <1 5>, <1 2>, <1 5>, <1 7>, <0 2>;
186             #mbox-cells = <2>;
187             compatible = "arm,mhuv2-rx", "arm,primecell";
190             clock-names = "apb_pclk";
192             arm,mhuv2-protocols = <1 1>, <1 7>, <0 2>;
196             compatible = "fsl,imx8qxp-dsp";
199             clock-names = "ipg", "ocram", "core";
200             power-domains = <&pd 0>, <&pd 1>, <&pd 2>, <&pd 3>;
201             mbox-names = "txdb0", "txdb1", "rxdb0", "rxdb1";
202             mboxes = <&mhu_tx 2 0>, //data-transfer protocol with 5 windows, mhu-tx
203                      <&mhu_tx 3 0>, //data-transfer protocol with 7 windows, mhu-tx
204                      <&mhu_rx 2 27>, //doorbell protocol channel 2, doorbell 27, mhu-rx
205                      <&mhu_rx 0 0>;  //data-transfer protocol with 1 window, mhu-rx
206             memory-region = <&dsp_reserved>;