diff options
| -rw-r--r-- | Documentation/devicetree/bindings/mailbox/arm,mhu.yaml | 60 |
1 files changed, 54 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhu.yaml b/Documentation/devicetree/bindings/mailbox/arm,mhu.yaml index 2c8df7979c22..d43791a2dde7 100644 --- a/Documentation/devicetree/bindings/mailbox/arm,mhu.yaml +++ b/Documentation/devicetree/bindings/mailbox/arm,mhu.yaml @@ -18,20 +18,40 @@ description: | remote clears it after having read the data. The last channel is specified to be a 'Secure' resource, hence can't be used by Linux running NS. + The MHU hardware also allows operations in doorbell mode. The MHU drives the + interrupt signal using a 32-bit register, with all 32-bits logically ORed + together. It provides a set of registers to enable software to set, clear and + check the status of each of the bits of this register independently. The use + of 32 bits per interrupt line enables software to provide more information + about the source of the interrupt. For example, each bit of the register can + be associated with a type of event that can contribute to raising the + interrupt. Each of the 32-bits can be used as "doorbell" to alert the remote + processor. + # We need a select here so we don't match all nodes with 'arm,primecell' select: properties: compatible: contains: - const: arm,mhu + enum: + - arm,mhu + - arm,mhu-doorbell required: - compatible properties: compatible: - items: - - const: arm,mhu - - const: arm,primecell + oneOf: + - description: Data transfer mode + items: + - const: arm,mhu + - const: arm,primecell + + - description: Doorbell mode + items: + - const: arm,mhu-doorbell + - const: arm,primecell + reg: maxItems: 1 @@ -51,8 +71,11 @@ properties: - const: apb_pclk '#mbox-cells': - description: Index of the channel. - const: 1 + description: | + Set to 1 in data transfer mode and represents index of the channel. + Set to 2 in doorbell mode and represents index of the channel and doorbell + number. + enum: [ 1, 2 ] required: - compatible @@ -63,6 +86,7 @@ required: additionalProperties: false examples: + # Data transfer mode. - | soc { #address-cells = <2>; @@ -85,3 +109,27 @@ examples: mboxes = <&mhuA 1>; /* HP-NonSecure */ }; }; + + # Doorbell mode. + - | + soc { + #address-cells = <2>; + #size-cells = <2>; + + mhuB: mailbox@2b2f0000 { + #mbox-cells = <2>; + compatible = "arm,mhu-doorbell", "arm,primecell"; + reg = <0 0x2b2f0000 0 0x1000>; + interrupts = <0 36 4>, /* LP-NonSecure */ + <0 35 4>, /* HP-NonSecure */ + <0 37 4>; /* Secure */ + clocks = <&clock 0 2 1>; + clock-names = "apb_pclk"; + }; + + mhu_client_scpi: scpi@2f000000 { + compatible = "arm,scpi"; + reg = <0 0x2f000000 0 0x200>; + mboxes = <&mhuB 1 4>; /* HP-NonSecure, 5th doorbell */ + }; + }; |