bindings/mailbox/arm%2Cmhuv2.yaml

1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
3 ---
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
10   - Tushar Khandelwal <tushar.khandelwal@arm.com>
11   - Viresh Kumar <viresh.kumar@linaro.org>
14   The Arm Message Handling Unit (MHU) Version 2 is a mailbox controller that has
15   between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
20   be written to or read from. If a pair of MHU controllers is implemented
27   An MHU controller must be specified along with the supported transport
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
39     may be transmitted through a shared memory region, wherein the MHU is used
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
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
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.
111       mhu: mailbox@2b1f0000 {
114           arm,mhuv2-protocols = <0 2>, <1 1>, <1 5>, <1 7>;
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
142       mboxes = <&mhu 0 5>; // Channel Window Group 0, doorbell 5.
143       mboxes = <&mhu 1 7>; // Channel Window Group 1, doorbell 7.
144       mboxes = <&mhu 2 0>; // Channel Window Group 2, data transfer protocol with 1 window.
145       mboxes = <&mhu 3 0>; // Channel Window Group 3, data transfer protocol with 5 windows.
146       mboxes = <&mhu 4 0>; // Channel Window Group 4, data transfer protocol with 7 windows.
155         const: arm,mhuv2-rx
158     - interrupts
161   - compatible
162   - reg
163   - '#mbox-cells'
164   - arm,mhuv2-protocols
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>;