* [PATCH V3] dt-bindings: mailbox: arm,mhuv2: Add bindings
@ 2020-10-09 11:42 ` Viresh Kumar
0 siblings, 0 replies; 8+ messages in thread
From: Viresh Kumar @ 2020-10-09 11:42 UTC (permalink / raw)
To: Rob Herring, Jassi Brar, morten_bp, Tushar Khandelwal, Viresh Kumar
Cc: linux-arm-kernel, Vincent Guittot, devicetree, Sudeep.Holla,
Frank Rowand, Tushar Khandelwal, linux-kernel
This patch adds device tree binding for ARM Message Handling Unit (MHU)
controller version 2.
Based on earlier work by Morten Borup Petersen.
Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
V2->V3:
- compatible is changed to arm-mhuv2-tx/rx. Later version of MHUv2
have an interrupt in the sender mode as well and we can't find if a
mailbox is sender or receiver just based on an interrupt anymore. We
needed a better way.
- arm-mhuv2-mode is renamed to arm,mhuv2-protocols to fit the purpose
better.
- Minor formatting otherwise.
- No longer an RFC.
Morten: Please let me know if you want me to add your sign-off here from
some other email id as you no longer work with ARM.
---
.../bindings/mailbox/arm,mhuv2.yaml | 194 ++++++++++++++++++
1 file changed, 194 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
new file mode 100644
index 000000000000..a2b8ecd639c7
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
@@ -0,0 +1,194 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/arm,mhuv2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM MHUv2 Mailbox Controller
+
+maintainers:
+ - Tushar Khandelwal <tushar.khandelwal@arm.com>
+ - Viresh Kumar <viresh.kumar@linaro.org>
+
+description: |
+ The Arm Message Handling Unit (MHU) Version 2 is a mailbox controller that has
+ between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
+ communication with remote processor(s), where the number of channel windows
+ are implementation dependent.
+
+ Given the unidirectional nature of the controller, an MHUv2 mailbox may only
+ be written to or read from. If a pair of MHU controllers is implemented
+ between two processing elements to provide bidirectional communication, these
+ must be specified as two separate mailboxes.
+
+ If the interrupts property is present in device tree node, then its treated as
+ a "receiver" mailbox, otherwise a "sender".
+
+ An MHU controller must be specified along with the supported transport
+ protocols. The transport protocols determine the method of data transmission
+ as well as the number of provided mailbox channels.
+
+ Following are the possible transport protocols.
+
+ - Doorbell: Each transfer is made up of single bit flag, using any one of the
+ bits in a channel window. A channel window can support up to 32 doorbells
+ and the entire window shall be used in doorbell protocol. Optionally, data
+ may be transmitted through a shared memory region, wherein the MHU is used
+ strictly as an interrupt generation mechanism but that is out of the scope
+ of these bindings.
+
+ - Single-word: Each transfer is single word, using a single Channel window.
+
+ - Multi-word: Each transfer is made of two or more words, using two or more
+ channel windows.
+
+# We need a select here so we don't match all nodes with 'arm,primecell'
+select:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - arm,mhuv2-tx
+ - arm,mhuv2-rx
+ required:
+ - compatible
+
+properties:
+ compatible:
+ oneOf:
+ - description: Sender mode
+ items:
+ - const: arm,mhuv2-tx
+ - const: arm,primecell
+
+ - description: Receiver-mode
+ items:
+ - const: arm,mhuv2-rx
+ - const: arm,primecell
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ description: |
+ The MHUv2 controller always implements an interrupt in the "receiver"
+ mode, while the interrupt in the "sender" mode was not available in the
+ version MHUv2.0, but the later versions do have it.
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ maxItems: 1
+
+ arm,mhuv2-protocols:
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+ description: |
+ The MHUv2 controller may contain up to 124 channel windows (each 32-bit
+ wide). The hardware and the DT bindings allows any combination of those to
+ be used for various transport protocols.
+
+ This property allows a platform to describe how these channel windows are
+ used in various transport protocols. The entries in this property shall be
+ present as an array of tuples, where each tuple describes details about
+ one of the transport protocol being implemented over some channel
+ window(s).
+
+ The first field of a tuple signifies the transfer protocol, 0 is reserved
+ for doorbell protocol, 1 is reserved for single-word protocol and 2 is
+ reserved for multi-word protocol. Using any other value in the first field
+ of a tuple makes it invalid.
+
+ The second field of a tuple signifies the number of channel windows where
+ the protocol would be used. For doorbell protocol this field signifies the
+ number of 32-bit channel windows that implement the doorbell protocol. For
+ single-word protocol this field signifies the number of 32-bit channel
+ windows that implement separate single-word protocol mailbox channels. For
+ multi-word protocol this field signifies the number of channel windows
+ used for a multi-word protocol, it should be 2 or more.
+
+ The total number of channel windows specified here shouldn't be more than
+ the ones implemented by the platform, though one can specify lesser number
+ of windows here than what the platform implements.
+
+ mhu: mailbox@2b1f0000 {
+ ...
+
+ arm,mhuv2-protocols = <0 2>, <1 3>, <2 5>, <2 7>;
+ }
+
+ The above example defines the protocols of an ARM MHUv2 mailbox
+ controller, where a total of 17 channel windows are used. The first two
+ windows are used in doorbell protocol (64 doorbells), the next 3 windows
+ are (separately) used in single-word protocol, and the last two mailbox
+ channels are used in multi-word protocol of length 5 and 7 channel
+ windows.
+
+ '#mbox-cells':
+ description: |
+ It contains two fields, the first field represents the channel number,
+ which may be used in doorbell, single-word, or multi-word protocol, and
+ the second field (only relevant in doorbell protocol, should be 0
+ otherwise) represents the doorbell number within the 32 bit wide channel
+ window.
+
+ From the example given above for the arm,mhuv2-protocols, here is how a
+ client node can reference them.
+
+ mboxes = <&mhu 0 5>; // Mailbox channel 0, doorbell 5.
+ mboxes = <&mhu 1 7>; // Mailbox channel 1, doorbell 7.
+ mboxes = <&mhu 2 0>; // Mailbox channel 2, single-word protocol.
+ mboxes = <&mhu 4 0>; // Mailbox channel 4, single-word protocol.
+ mboxes = <&mhu 6 0>; // Mailbox channel 6, multi-word protocol with 7 windows.
+
+ const: 2
+
+required:
+ - compatible
+ - reg
+ - '#mbox-cells'
+ - arm,mhuv2-protocols
+
+additionalProperties: false
+
+examples:
+ # Multiple transport protocols implemented by the mailbox controllers
+ - |
+ soc {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ mhu_tx: mailbox-tx@2b1f0000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhuv2-tx", "arm,primecell";
+ reg = <0 0x2b1f0000 0 0x1000>;
+ clocks = <&clock 0>;
+ clock-names = "apb_pclk";
+ arm,mhuv2-protocols = <1 5>, <2 2>, <2 5>, <2 7>, <0 2>;
+ };
+
+ mhu_rx: mailbox-rx@2b1f1000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhuv2-rx", "arm,primecell";
+ reg = <0 0x2b1f1000 0 0x1000>;
+ clocks = <&clock 0>;
+ clock-names = "apb_pclk";
+ arm,mhuv2-protocols = <1 5>, <2 7>, <0 2>;
+ };
+
+ mhu_client: scb@2e000000 {
+ compatible = "fujitsu,mb86s70-scb-1.0";
+ reg = <0 0x2e000000 0 0x4000>;
+
+ mboxes =
+ //single-word protocol channel 0, mhu-rx
+ <&mhu_rx 0 0>,
+ //single-word protocol channel 4, mhu-tx
+ <&mhu_tx 4 0>,
+ //multi-word protocol channel 6 with 5 windows, mhu-tx
+ <&mhu_tx 6 0>,
+ //doorbell protocol channel 9, doorbell 27, mhu-tx
+ <&mhu_tx 9 27>;
+ };
+ };
--
2.25.0.rc1.19.g042ed3e048af
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH V3] dt-bindings: mailbox: arm,mhuv2: Add bindings
@ 2020-10-09 11:42 ` Viresh Kumar
0 siblings, 0 replies; 8+ messages in thread
From: Viresh Kumar @ 2020-10-09 11:42 UTC (permalink / raw)
To: Rob Herring, Jassi Brar, morten_bp, Tushar Khandelwal, Viresh Kumar
Cc: devicetree, Vincent Guittot, linux-kernel, Tushar Khandelwal,
Sudeep.Holla, Frank Rowand, linux-arm-kernel
This patch adds device tree binding for ARM Message Handling Unit (MHU)
controller version 2.
Based on earlier work by Morten Borup Petersen.
Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
V2->V3:
- compatible is changed to arm-mhuv2-tx/rx. Later version of MHUv2
have an interrupt in the sender mode as well and we can't find if a
mailbox is sender or receiver just based on an interrupt anymore. We
needed a better way.
- arm-mhuv2-mode is renamed to arm,mhuv2-protocols to fit the purpose
better.
- Minor formatting otherwise.
- No longer an RFC.
Morten: Please let me know if you want me to add your sign-off here from
some other email id as you no longer work with ARM.
---
.../bindings/mailbox/arm,mhuv2.yaml | 194 ++++++++++++++++++
1 file changed, 194 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
new file mode 100644
index 000000000000..a2b8ecd639c7
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
@@ -0,0 +1,194 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/arm,mhuv2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM MHUv2 Mailbox Controller
+
+maintainers:
+ - Tushar Khandelwal <tushar.khandelwal@arm.com>
+ - Viresh Kumar <viresh.kumar@linaro.org>
+
+description: |
+ The Arm Message Handling Unit (MHU) Version 2 is a mailbox controller that has
+ between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
+ communication with remote processor(s), where the number of channel windows
+ are implementation dependent.
+
+ Given the unidirectional nature of the controller, an MHUv2 mailbox may only
+ be written to or read from. If a pair of MHU controllers is implemented
+ between two processing elements to provide bidirectional communication, these
+ must be specified as two separate mailboxes.
+
+ If the interrupts property is present in device tree node, then its treated as
+ a "receiver" mailbox, otherwise a "sender".
+
+ An MHU controller must be specified along with the supported transport
+ protocols. The transport protocols determine the method of data transmission
+ as well as the number of provided mailbox channels.
+
+ Following are the possible transport protocols.
+
+ - Doorbell: Each transfer is made up of single bit flag, using any one of the
+ bits in a channel window. A channel window can support up to 32 doorbells
+ and the entire window shall be used in doorbell protocol. Optionally, data
+ may be transmitted through a shared memory region, wherein the MHU is used
+ strictly as an interrupt generation mechanism but that is out of the scope
+ of these bindings.
+
+ - Single-word: Each transfer is single word, using a single Channel window.
+
+ - Multi-word: Each transfer is made of two or more words, using two or more
+ channel windows.
+
+# We need a select here so we don't match all nodes with 'arm,primecell'
+select:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - arm,mhuv2-tx
+ - arm,mhuv2-rx
+ required:
+ - compatible
+
+properties:
+ compatible:
+ oneOf:
+ - description: Sender mode
+ items:
+ - const: arm,mhuv2-tx
+ - const: arm,primecell
+
+ - description: Receiver-mode
+ items:
+ - const: arm,mhuv2-rx
+ - const: arm,primecell
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ description: |
+ The MHUv2 controller always implements an interrupt in the "receiver"
+ mode, while the interrupt in the "sender" mode was not available in the
+ version MHUv2.0, but the later versions do have it.
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ maxItems: 1
+
+ arm,mhuv2-protocols:
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+ description: |
+ The MHUv2 controller may contain up to 124 channel windows (each 32-bit
+ wide). The hardware and the DT bindings allows any combination of those to
+ be used for various transport protocols.
+
+ This property allows a platform to describe how these channel windows are
+ used in various transport protocols. The entries in this property shall be
+ present as an array of tuples, where each tuple describes details about
+ one of the transport protocol being implemented over some channel
+ window(s).
+
+ The first field of a tuple signifies the transfer protocol, 0 is reserved
+ for doorbell protocol, 1 is reserved for single-word protocol and 2 is
+ reserved for multi-word protocol. Using any other value in the first field
+ of a tuple makes it invalid.
+
+ The second field of a tuple signifies the number of channel windows where
+ the protocol would be used. For doorbell protocol this field signifies the
+ number of 32-bit channel windows that implement the doorbell protocol. For
+ single-word protocol this field signifies the number of 32-bit channel
+ windows that implement separate single-word protocol mailbox channels. For
+ multi-word protocol this field signifies the number of channel windows
+ used for a multi-word protocol, it should be 2 or more.
+
+ The total number of channel windows specified here shouldn't be more than
+ the ones implemented by the platform, though one can specify lesser number
+ of windows here than what the platform implements.
+
+ mhu: mailbox@2b1f0000 {
+ ...
+
+ arm,mhuv2-protocols = <0 2>, <1 3>, <2 5>, <2 7>;
+ }
+
+ The above example defines the protocols of an ARM MHUv2 mailbox
+ controller, where a total of 17 channel windows are used. The first two
+ windows are used in doorbell protocol (64 doorbells), the next 3 windows
+ are (separately) used in single-word protocol, and the last two mailbox
+ channels are used in multi-word protocol of length 5 and 7 channel
+ windows.
+
+ '#mbox-cells':
+ description: |
+ It contains two fields, the first field represents the channel number,
+ which may be used in doorbell, single-word, or multi-word protocol, and
+ the second field (only relevant in doorbell protocol, should be 0
+ otherwise) represents the doorbell number within the 32 bit wide channel
+ window.
+
+ From the example given above for the arm,mhuv2-protocols, here is how a
+ client node can reference them.
+
+ mboxes = <&mhu 0 5>; // Mailbox channel 0, doorbell 5.
+ mboxes = <&mhu 1 7>; // Mailbox channel 1, doorbell 7.
+ mboxes = <&mhu 2 0>; // Mailbox channel 2, single-word protocol.
+ mboxes = <&mhu 4 0>; // Mailbox channel 4, single-word protocol.
+ mboxes = <&mhu 6 0>; // Mailbox channel 6, multi-word protocol with 7 windows.
+
+ const: 2
+
+required:
+ - compatible
+ - reg
+ - '#mbox-cells'
+ - arm,mhuv2-protocols
+
+additionalProperties: false
+
+examples:
+ # Multiple transport protocols implemented by the mailbox controllers
+ - |
+ soc {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ mhu_tx: mailbox-tx@2b1f0000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhuv2-tx", "arm,primecell";
+ reg = <0 0x2b1f0000 0 0x1000>;
+ clocks = <&clock 0>;
+ clock-names = "apb_pclk";
+ arm,mhuv2-protocols = <1 5>, <2 2>, <2 5>, <2 7>, <0 2>;
+ };
+
+ mhu_rx: mailbox-rx@2b1f1000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhuv2-rx", "arm,primecell";
+ reg = <0 0x2b1f1000 0 0x1000>;
+ clocks = <&clock 0>;
+ clock-names = "apb_pclk";
+ arm,mhuv2-protocols = <1 5>, <2 7>, <0 2>;
+ };
+
+ mhu_client: scb@2e000000 {
+ compatible = "fujitsu,mb86s70-scb-1.0";
+ reg = <0 0x2e000000 0 0x4000>;
+
+ mboxes =
+ //single-word protocol channel 0, mhu-rx
+ <&mhu_rx 0 0>,
+ //single-word protocol channel 4, mhu-tx
+ <&mhu_tx 4 0>,
+ //multi-word protocol channel 6 with 5 windows, mhu-tx
+ <&mhu_tx 6 0>,
+ //doorbell protocol channel 9, doorbell 27, mhu-tx
+ <&mhu_tx 9 27>;
+ };
+ };
--
2.25.0.rc1.19.g042ed3e048af
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^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH V3] dt-bindings: mailbox: arm,mhuv2: Add bindings
2020-10-09 11:42 ` Viresh Kumar
@ 2020-10-12 19:16 ` Rob Herring
-1 siblings, 0 replies; 8+ messages in thread
From: Rob Herring @ 2020-10-12 19:16 UTC (permalink / raw)
To: Viresh Kumar
Cc: Jassi Brar, morten_bp, Tushar Khandelwal, linux-arm-kernel,
Vincent Guittot, devicetree, Sudeep.Holla, Frank Rowand,
linux-kernel
On Fri, Oct 09, 2020 at 05:12:38PM +0530, Viresh Kumar wrote:
> This patch adds device tree binding for ARM Message Handling Unit (MHU)
> controller version 2.
>
> Based on earlier work by Morten Borup Petersen.
>
> Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
> Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>
> ---
> V2->V3:
>
> - compatible is changed to arm-mhuv2-tx/rx. Later version of MHUv2
> have an interrupt in the sender mode as well and we can't find if a
> mailbox is sender or receiver just based on an interrupt anymore. We
> needed a better way.
>
> - arm-mhuv2-mode is renamed to arm,mhuv2-protocols to fit the purpose
> better.
>
> - Minor formatting otherwise.
>
> - No longer an RFC.
>
> Morten: Please let me know if you want me to add your sign-off here from
> some other email id as you no longer work with ARM.
> ---
> .../bindings/mailbox/arm,mhuv2.yaml | 194 ++++++++++++++++++
> 1 file changed, 194 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
>
> diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
> new file mode 100644
> index 000000000000..a2b8ecd639c7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
> @@ -0,0 +1,194 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mailbox/arm,mhuv2.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ARM MHUv2 Mailbox Controller
> +
> +maintainers:
> + - Tushar Khandelwal <tushar.khandelwal@arm.com>
> + - Viresh Kumar <viresh.kumar@linaro.org>
> +
> +description: |
> + The Arm Message Handling Unit (MHU) Version 2 is a mailbox controller that has
> + between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
> + communication with remote processor(s), where the number of channel windows
> + are implementation dependent.
> +
> + Given the unidirectional nature of the controller, an MHUv2 mailbox may only
> + be written to or read from. If a pair of MHU controllers is implemented
> + between two processing elements to provide bidirectional communication, these
> + must be specified as two separate mailboxes.
> +
> + If the interrupts property is present in device tree node, then its treated as
> + a "receiver" mailbox, otherwise a "sender".
> +
> + An MHU controller must be specified along with the supported transport
> + protocols. The transport protocols determine the method of data transmission
> + as well as the number of provided mailbox channels.
> +
> + Following are the possible transport protocols.
> +
> + - Doorbell: Each transfer is made up of single bit flag, using any one of the
> + bits in a channel window. A channel window can support up to 32 doorbells
> + and the entire window shall be used in doorbell protocol. Optionally, data
> + may be transmitted through a shared memory region, wherein the MHU is used
> + strictly as an interrupt generation mechanism but that is out of the scope
> + of these bindings.
> +
> + - Single-word: Each transfer is single word, using a single Channel window.
> +
> + - Multi-word: Each transfer is made of two or more words, using two or more
> + channel windows.
> +
> +# We need a select here so we don't match all nodes with 'arm,primecell'
> +select:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - arm,mhuv2-tx
> + - arm,mhuv2-rx
> + required:
> + - compatible
> +
> +properties:
> + compatible:
> + oneOf:
> + - description: Sender mode
> + items:
> + - const: arm,mhuv2-tx
> + - const: arm,primecell
> +
> + - description: Receiver-mode
> + items:
> + - const: arm,mhuv2-rx
> + - const: arm,primecell
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + description: |
> + The MHUv2 controller always implements an interrupt in the "receiver"
> + mode, while the interrupt in the "sender" mode was not available in the
> + version MHUv2.0, but the later versions do have it.
> + maxItems: 1
> +
> + clocks:
> + maxItems: 1
> +
> + clock-names:
> + maxItems: 1
> +
> + arm,mhuv2-protocols:
> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
> + description: |
> + The MHUv2 controller may contain up to 124 channel windows (each 32-bit
> + wide). The hardware and the DT bindings allows any combination of those to
> + be used for various transport protocols.
> +
> + This property allows a platform to describe how these channel windows are
> + used in various transport protocols. The entries in this property shall be
> + present as an array of tuples, where each tuple describes details about
> + one of the transport protocol being implemented over some channel
> + window(s).
> +
> + The first field of a tuple signifies the transfer protocol, 0 is reserved
> + for doorbell protocol, 1 is reserved for single-word protocol and 2 is
> + reserved for multi-word protocol. Using any other value in the first field
> + of a tuple makes it invalid.
> +
> + The second field of a tuple signifies the number of channel windows where
> + the protocol would be used. For doorbell protocol this field signifies the
> + number of 32-bit channel windows that implement the doorbell protocol. For
> + single-word protocol this field signifies the number of 32-bit channel
> + windows that implement separate single-word protocol mailbox channels. For
> + multi-word protocol this field signifies the number of channel windows
> + used for a multi-word protocol, it should be 2 or more.
> +
> + The total number of channel windows specified here shouldn't be more than
> + the ones implemented by the platform, though one can specify lesser number
> + of windows here than what the platform implements.
> +
> + mhu: mailbox@2b1f0000 {
> + ...
> +
> + arm,mhuv2-protocols = <0 2>, <1 3>, <2 5>, <2 7>;
> + }
> +
> + The above example defines the protocols of an ARM MHUv2 mailbox
> + controller, where a total of 17 channel windows are used. The first two
> + windows are used in doorbell protocol (64 doorbells), the next 3 windows
> + are (separately) used in single-word protocol, and the last two mailbox
> + channels are used in multi-word protocol of length 5 and 7 channel
> + windows.
I think in terms of constraints, this would be:
minItems: 1
maxItems: 124
items:
items:
- enum: [ 0, 1, 2 ]
- minimum: 0
maximum: 124
> +
> + '#mbox-cells':
> + description: |
> + It contains two fields, the first field represents the channel number,
> + which may be used in doorbell, single-word, or multi-word protocol, and
> + the second field (only relevant in doorbell protocol, should be 0
> + otherwise) represents the doorbell number within the 32 bit wide channel
> + window.
> +
> + From the example given above for the arm,mhuv2-protocols, here is how a
> + client node can reference them.
> +
> + mboxes = <&mhu 0 5>; // Mailbox channel 0, doorbell 5.
> + mboxes = <&mhu 1 7>; // Mailbox channel 1, doorbell 7.
> + mboxes = <&mhu 2 0>; // Mailbox channel 2, single-word protocol.
> + mboxes = <&mhu 4 0>; // Mailbox channel 4, single-word protocol.
> + mboxes = <&mhu 6 0>; // Mailbox channel 6, multi-word protocol with 7 windows.
> +
> + const: 2
> +
> +required:
> + - compatible
> + - reg
> + - '#mbox-cells'
> + - arm,mhuv2-protocols
> +
> +additionalProperties: false
> +
> +examples:
> + # Multiple transport protocols implemented by the mailbox controllers
> + - |
> + soc {
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + mhu_tx: mailbox-tx@2b1f0000 {
mailbox@...
Direction is not relevant for node name.
> + #mbox-cells = <2>;
> + compatible = "arm,mhuv2-tx", "arm,primecell";
> + reg = <0 0x2b1f0000 0 0x1000>;
> + clocks = <&clock 0>;
> + clock-names = "apb_pclk";
> + arm,mhuv2-protocols = <1 5>, <2 2>, <2 5>, <2 7>, <0 2>;
> + };
> +
> + mhu_rx: mailbox-rx@2b1f1000 {
> + #mbox-cells = <2>;
> + compatible = "arm,mhuv2-rx", "arm,primecell";
> + reg = <0 0x2b1f1000 0 0x1000>;
> + clocks = <&clock 0>;
> + clock-names = "apb_pclk";
> + arm,mhuv2-protocols = <1 5>, <2 7>, <0 2>;
A receiver with no interrupt? Should be conditionally required?
> + };
> +
> + mhu_client: scb@2e000000 {
> + compatible = "fujitsu,mb86s70-scb-1.0";
> + reg = <0 0x2e000000 0 0x4000>;
> +
> + mboxes =
> + //single-word protocol channel 0, mhu-rx
> + <&mhu_rx 0 0>,
> + //single-word protocol channel 4, mhu-tx
> + <&mhu_tx 4 0>,
> + //multi-word protocol channel 6 with 5 windows, mhu-tx
> + <&mhu_tx 6 0>,
> + //doorbell protocol channel 9, doorbell 27, mhu-tx
> + <&mhu_tx 9 27>;
> + };
> + };
> --
> 2.25.0.rc1.19.g042ed3e048af
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH V3] dt-bindings: mailbox: arm,mhuv2: Add bindings
@ 2020-10-12 19:16 ` Rob Herring
0 siblings, 0 replies; 8+ messages in thread
From: Rob Herring @ 2020-10-12 19:16 UTC (permalink / raw)
To: Viresh Kumar
Cc: devicetree, Vincent Guittot, linux-kernel, Jassi Brar, morten_bp,
Tushar Khandelwal, Sudeep.Holla, Frank Rowand, linux-arm-kernel
On Fri, Oct 09, 2020 at 05:12:38PM +0530, Viresh Kumar wrote:
> This patch adds device tree binding for ARM Message Handling Unit (MHU)
> controller version 2.
>
> Based on earlier work by Morten Borup Petersen.
>
> Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
> Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>
> ---
> V2->V3:
>
> - compatible is changed to arm-mhuv2-tx/rx. Later version of MHUv2
> have an interrupt in the sender mode as well and we can't find if a
> mailbox is sender or receiver just based on an interrupt anymore. We
> needed a better way.
>
> - arm-mhuv2-mode is renamed to arm,mhuv2-protocols to fit the purpose
> better.
>
> - Minor formatting otherwise.
>
> - No longer an RFC.
>
> Morten: Please let me know if you want me to add your sign-off here from
> some other email id as you no longer work with ARM.
> ---
> .../bindings/mailbox/arm,mhuv2.yaml | 194 ++++++++++++++++++
> 1 file changed, 194 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
>
> diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
> new file mode 100644
> index 000000000000..a2b8ecd639c7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
> @@ -0,0 +1,194 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mailbox/arm,mhuv2.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ARM MHUv2 Mailbox Controller
> +
> +maintainers:
> + - Tushar Khandelwal <tushar.khandelwal@arm.com>
> + - Viresh Kumar <viresh.kumar@linaro.org>
> +
> +description: |
> + The Arm Message Handling Unit (MHU) Version 2 is a mailbox controller that has
> + between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
> + communication with remote processor(s), where the number of channel windows
> + are implementation dependent.
> +
> + Given the unidirectional nature of the controller, an MHUv2 mailbox may only
> + be written to or read from. If a pair of MHU controllers is implemented
> + between two processing elements to provide bidirectional communication, these
> + must be specified as two separate mailboxes.
> +
> + If the interrupts property is present in device tree node, then its treated as
> + a "receiver" mailbox, otherwise a "sender".
> +
> + An MHU controller must be specified along with the supported transport
> + protocols. The transport protocols determine the method of data transmission
> + as well as the number of provided mailbox channels.
> +
> + Following are the possible transport protocols.
> +
> + - Doorbell: Each transfer is made up of single bit flag, using any one of the
> + bits in a channel window. A channel window can support up to 32 doorbells
> + and the entire window shall be used in doorbell protocol. Optionally, data
> + may be transmitted through a shared memory region, wherein the MHU is used
> + strictly as an interrupt generation mechanism but that is out of the scope
> + of these bindings.
> +
> + - Single-word: Each transfer is single word, using a single Channel window.
> +
> + - Multi-word: Each transfer is made of two or more words, using two or more
> + channel windows.
> +
> +# We need a select here so we don't match all nodes with 'arm,primecell'
> +select:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - arm,mhuv2-tx
> + - arm,mhuv2-rx
> + required:
> + - compatible
> +
> +properties:
> + compatible:
> + oneOf:
> + - description: Sender mode
> + items:
> + - const: arm,mhuv2-tx
> + - const: arm,primecell
> +
> + - description: Receiver-mode
> + items:
> + - const: arm,mhuv2-rx
> + - const: arm,primecell
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + description: |
> + The MHUv2 controller always implements an interrupt in the "receiver"
> + mode, while the interrupt in the "sender" mode was not available in the
> + version MHUv2.0, but the later versions do have it.
> + maxItems: 1
> +
> + clocks:
> + maxItems: 1
> +
> + clock-names:
> + maxItems: 1
> +
> + arm,mhuv2-protocols:
> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
> + description: |
> + The MHUv2 controller may contain up to 124 channel windows (each 32-bit
> + wide). The hardware and the DT bindings allows any combination of those to
> + be used for various transport protocols.
> +
> + This property allows a platform to describe how these channel windows are
> + used in various transport protocols. The entries in this property shall be
> + present as an array of tuples, where each tuple describes details about
> + one of the transport protocol being implemented over some channel
> + window(s).
> +
> + The first field of a tuple signifies the transfer protocol, 0 is reserved
> + for doorbell protocol, 1 is reserved for single-word protocol and 2 is
> + reserved for multi-word protocol. Using any other value in the first field
> + of a tuple makes it invalid.
> +
> + The second field of a tuple signifies the number of channel windows where
> + the protocol would be used. For doorbell protocol this field signifies the
> + number of 32-bit channel windows that implement the doorbell protocol. For
> + single-word protocol this field signifies the number of 32-bit channel
> + windows that implement separate single-word protocol mailbox channels. For
> + multi-word protocol this field signifies the number of channel windows
> + used for a multi-word protocol, it should be 2 or more.
> +
> + The total number of channel windows specified here shouldn't be more than
> + the ones implemented by the platform, though one can specify lesser number
> + of windows here than what the platform implements.
> +
> + mhu: mailbox@2b1f0000 {
> + ...
> +
> + arm,mhuv2-protocols = <0 2>, <1 3>, <2 5>, <2 7>;
> + }
> +
> + The above example defines the protocols of an ARM MHUv2 mailbox
> + controller, where a total of 17 channel windows are used. The first two
> + windows are used in doorbell protocol (64 doorbells), the next 3 windows
> + are (separately) used in single-word protocol, and the last two mailbox
> + channels are used in multi-word protocol of length 5 and 7 channel
> + windows.
I think in terms of constraints, this would be:
minItems: 1
maxItems: 124
items:
items:
- enum: [ 0, 1, 2 ]
- minimum: 0
maximum: 124
> +
> + '#mbox-cells':
> + description: |
> + It contains two fields, the first field represents the channel number,
> + which may be used in doorbell, single-word, or multi-word protocol, and
> + the second field (only relevant in doorbell protocol, should be 0
> + otherwise) represents the doorbell number within the 32 bit wide channel
> + window.
> +
> + From the example given above for the arm,mhuv2-protocols, here is how a
> + client node can reference them.
> +
> + mboxes = <&mhu 0 5>; // Mailbox channel 0, doorbell 5.
> + mboxes = <&mhu 1 7>; // Mailbox channel 1, doorbell 7.
> + mboxes = <&mhu 2 0>; // Mailbox channel 2, single-word protocol.
> + mboxes = <&mhu 4 0>; // Mailbox channel 4, single-word protocol.
> + mboxes = <&mhu 6 0>; // Mailbox channel 6, multi-word protocol with 7 windows.
> +
> + const: 2
> +
> +required:
> + - compatible
> + - reg
> + - '#mbox-cells'
> + - arm,mhuv2-protocols
> +
> +additionalProperties: false
> +
> +examples:
> + # Multiple transport protocols implemented by the mailbox controllers
> + - |
> + soc {
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + mhu_tx: mailbox-tx@2b1f0000 {
mailbox@...
Direction is not relevant for node name.
> + #mbox-cells = <2>;
> + compatible = "arm,mhuv2-tx", "arm,primecell";
> + reg = <0 0x2b1f0000 0 0x1000>;
> + clocks = <&clock 0>;
> + clock-names = "apb_pclk";
> + arm,mhuv2-protocols = <1 5>, <2 2>, <2 5>, <2 7>, <0 2>;
> + };
> +
> + mhu_rx: mailbox-rx@2b1f1000 {
> + #mbox-cells = <2>;
> + compatible = "arm,mhuv2-rx", "arm,primecell";
> + reg = <0 0x2b1f1000 0 0x1000>;
> + clocks = <&clock 0>;
> + clock-names = "apb_pclk";
> + arm,mhuv2-protocols = <1 5>, <2 7>, <0 2>;
A receiver with no interrupt? Should be conditionally required?
> + };
> +
> + mhu_client: scb@2e000000 {
> + compatible = "fujitsu,mb86s70-scb-1.0";
> + reg = <0 0x2e000000 0 0x4000>;
> +
> + mboxes =
> + //single-word protocol channel 0, mhu-rx
> + <&mhu_rx 0 0>,
> + //single-word protocol channel 4, mhu-tx
> + <&mhu_tx 4 0>,
> + //multi-word protocol channel 6 with 5 windows, mhu-tx
> + <&mhu_tx 6 0>,
> + //doorbell protocol channel 9, doorbell 27, mhu-tx
> + <&mhu_tx 9 27>;
> + };
> + };
> --
> 2.25.0.rc1.19.g042ed3e048af
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH V4] dt-bindings: mailbox : arm,mhuv2: Add bindings
2020-10-12 19:16 ` Rob Herring
@ 2020-10-13 4:32 ` Viresh Kumar
-1 siblings, 0 replies; 8+ messages in thread
From: Viresh Kumar @ 2020-10-13 4:32 UTC (permalink / raw)
To: Rob Herring, Jassi Brar, morten_bp, Tushar Khandelwal, Viresh Kumar
Cc: linux-arm-kernel, Vincent Guittot, devicetree, Sudeep.Holla,
Frank Rowand, Tushar Khandelwal, linux-kernel
This patch adds device tree binding for ARM Message Handling Unit (MHU)
controller version 2.
Based on earlier work by Morten Borup Petersen.
Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
V3->V4:
- Made interrupts property compulsory for receiver
- Added interrupts for both nodes in example
- Fixed min/max items for protocols property
- Don't add -tx/rx to node's name.
V2->V3:
- compatible is changed to arm-mhuv2-tx/rx. Later version of MHUv2
have an interrupt in the sender mode as well and we can't find if a
mailbox is sender or receiver just based on an interrupt anymore. We
needed a better way.
- arm-mhuv2-mode is renamed to arm,mhuv2-protocols to fit the purpose
better.
- Minor formatting otherwise.
Morten: Please let me know if you want me to add your signoff here from
some other email id as you no longer work with ARM.
---
.../bindings/mailbox/arm,mhuv2.yaml | 215 ++++++++++++++++++
1 file changed, 215 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
new file mode 100644
index 000000000000..013b7aeda713
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
@@ -0,0 +1,215 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/arm,mhuv2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM MHUv2 Mailbox Controller
+
+maintainers:
+ - Tushar Khandelwal <tushar.khandelwal@arm.com>
+ - Viresh Kumar <viresh.kumar@linaro.org>
+
+description: |
+ The Arm Message Handling Unit (MHU) Version 2 is a mailbox controller that has
+ between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
+ communication with remote processor(s), where the number of channel windows
+ are implementation dependent.
+
+ Given the unidirectional nature of the controller, an MHUv2 mailbox may only
+ be written to or read from. If a pair of MHU controllers is implemented
+ between two processing elements to provide bidirectional communication, these
+ must be specified as two separate mailboxes.
+
+ If the interrupts property is present in device tree node, then its treated as
+ a "receiver" mailbox, otherwise a "sender".
+
+ An MHU controller must be specified along with the supported transport
+ protocols. The transport protocols determine the method of data transmission
+ as well as the number of provided mailbox channels.
+
+ Following are the possible transport protocols.
+
+ - Doorbell: Each transfer is made up of single bit flag, using any one of the
+ bits in a channel window. A channel window can support up to 32 doorbells
+ and the entire window shall be used in doorbell protocol. Optionally, data
+ may be transmitted through a shared memory region, wherein the MHU is used
+ strictly as an interrupt generation mechanism but that is out of the scope
+ of these bindings.
+
+ - Single-word: Each transfer is single word, using a single Channel window.
+
+ - Multi-word: Each transfer is made of two or more words, using two or more
+ channel windows.
+
+# We need a select here so we don't match all nodes with 'arm,primecell'
+select:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - arm,mhuv2-tx
+ - arm,mhuv2-rx
+ required:
+ - compatible
+
+properties:
+ compatible:
+ oneOf:
+ - description: Sender mode
+ items:
+ - const: arm,mhuv2-tx
+ - const: arm,primecell
+
+ - description: Receiver-mode
+ items:
+ - const: arm,mhuv2-rx
+ - const: arm,primecell
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ description: |
+ The MHUv2 controller always implements an interrupt in the "receiver"
+ mode, while the interrupt in the "sender" mode was not available in the
+ version MHUv2.0, but the later versions do have it.
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ maxItems: 1
+
+ arm,mhuv2-protocols:
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+ description: |
+ The MHUv2 controller may contain up to 124 channel windows (each 32-bit
+ wide). The hardware and the DT bindings allows any combination of those to
+ be used for various transport protocols.
+
+ This property allows a platform to describe how these channel windows are
+ used in various transport protocols. The entries in this property shall be
+ present as an array of tuples, where each tuple describes details about
+ one of the transport protocol being implemented over some channel
+ window(s).
+
+ The first field of a tuple signifies the transfer protocol, 0 is reserved
+ for doorbell protocol, 1 is reserved for single-word protocol and 2 is
+ reserved for multi-word protocol. Using any other value in the first field
+ of a tuple makes it invalid.
+
+ The second field of a tuple signifies the number of channel windows where
+ the protocol would be used. For doorbell protocol this field signifies the
+ number of 32-bit channel windows that implement the doorbell protocol. For
+ single-word protocol this field signifies the number of 32-bit channel
+ windows that implement separate single-word protocol mailbox channels. For
+ multi-word protocol this field signifies the number of channel windows
+ used for a multi-word protocol, it should be 2 or more.
+
+ The total number of channel windows specified here shouldn't be more than
+ the ones implemented by the platform, though one can specify lesser number
+ of windows here than what the platform implements.
+
+ mhu: mailbox@2b1f0000 {
+ ...
+
+ arm,mhuv2-protocols = <0 2>, <1 3>, <2 5>, <2 7>;
+ }
+
+ The above example defines the protocols of an ARM MHUv2 mailbox
+ controller, where a total of 17 channel windows are used. The first two
+ windows are used in doorbell protocol (64 doorbells), the next 3 windows
+ are (separately) used in single-word protocol, and the last two mailbox
+ channels are used in multi-word protocol of length 5 and 7 channel
+ windows.
+
+ minItems: 1
+ maxItems: 124
+ items:
+ items:
+ - enum: [ 0, 1, 2 ]
+ - minimum: 0
+ maximum: 124
+
+
+ '#mbox-cells':
+ description: |
+ It contains two fields, the first field represents the channel number,
+ which may be used in doorbell, single-word, or multi-word protocol, and
+ the second field (only relevant in doorbell protocol, should be 0
+ otherwise) represents the doorbell number within the 32 bit wide channel
+ window.
+
+ From the example given above for the arm,mhuv2-protocols, here is how a
+ client node can reference them.
+
+ mboxes = <&mhu 0 5>; // Mailbox channel 0, doorbell 5.
+ mboxes = <&mhu 1 7>; // Mailbox channel 1, doorbell 7.
+ mboxes = <&mhu 2 0>; // Mailbox channel 2, single-word protocol.
+ mboxes = <&mhu 4 0>; // Mailbox channel 4, single-word protocol.
+ mboxes = <&mhu 6 0>; // Mailbox channel 6, multi-word protocol with 7 windows.
+
+ const: 2
+
+if:
+ # Interrupt is compulsory for receiver
+ properties:
+ compatible:
+ contains:
+ const: arm,mhuv2-rx
+then:
+ required:
+ - interrupts
+
+required:
+ - compatible
+ - reg
+ - '#mbox-cells'
+ - arm,mhuv2-protocols
+
+additionalProperties: false
+
+examples:
+ # Multiple transport protocols implemented by the mailbox controllers
+ - |
+ soc {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ mhu_tx: mailbox@2b1f0000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhuv2-tx", "arm,primecell";
+ reg = <0 0x2b1f0000 0 0x1000>;
+ clocks = <&clock 0>;
+ clock-names = "apb_pclk";
+ interrupts = <0 45 4>;
+ arm,mhuv2-protocols = <1 5>, <2 2>, <2 5>, <2 7>, <0 2>;
+ };
+
+ mhu_rx: mailbox@2b1f1000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhuv2-rx", "arm,primecell";
+ reg = <0 0x2b1f1000 0 0x1000>;
+ clocks = <&clock 0>;
+ clock-names = "apb_pclk";
+ interrupts = <0 46 4>;
+ arm,mhuv2-protocols = <1 5>, <2 7>, <0 2>;
+ };
+
+ mhu_client: scb@2e000000 {
+ compatible = "fujitsu,mb86s70-scb-1.0";
+ reg = <0 0x2e000000 0 0x4000>;
+
+ mboxes =
+ //single-word protocol channel 0, mhu-rx
+ <&mhu_rx 0 0>,
+ //single-word protocol channel 4, mhu-tx
+ <&mhu_tx 4 0>,
+ //multi-word protocol channel 6 with 5 windows, mhu-tx
+ <&mhu_tx 6 0>,
+ //doorbell protocol channel 9, doorbell 27, mhu-tx
+ <&mhu_tx 9 27>;
+ };
+ };
--
2.25.0.rc1.19.g042ed3e048af
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH V4] dt-bindings: mailbox : arm,mhuv2: Add bindings
@ 2020-10-13 4:32 ` Viresh Kumar
0 siblings, 0 replies; 8+ messages in thread
From: Viresh Kumar @ 2020-10-13 4:32 UTC (permalink / raw)
To: Rob Herring, Jassi Brar, morten_bp, Tushar Khandelwal, Viresh Kumar
Cc: devicetree, Vincent Guittot, linux-kernel, Tushar Khandelwal,
Sudeep.Holla, Frank Rowand, linux-arm-kernel
This patch adds device tree binding for ARM Message Handling Unit (MHU)
controller version 2.
Based on earlier work by Morten Borup Petersen.
Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
V3->V4:
- Made interrupts property compulsory for receiver
- Added interrupts for both nodes in example
- Fixed min/max items for protocols property
- Don't add -tx/rx to node's name.
V2->V3:
- compatible is changed to arm-mhuv2-tx/rx. Later version of MHUv2
have an interrupt in the sender mode as well and we can't find if a
mailbox is sender or receiver just based on an interrupt anymore. We
needed a better way.
- arm-mhuv2-mode is renamed to arm,mhuv2-protocols to fit the purpose
better.
- Minor formatting otherwise.
Morten: Please let me know if you want me to add your signoff here from
some other email id as you no longer work with ARM.
---
.../bindings/mailbox/arm,mhuv2.yaml | 215 ++++++++++++++++++
1 file changed, 215 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
new file mode 100644
index 000000000000..013b7aeda713
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
@@ -0,0 +1,215 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/arm,mhuv2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM MHUv2 Mailbox Controller
+
+maintainers:
+ - Tushar Khandelwal <tushar.khandelwal@arm.com>
+ - Viresh Kumar <viresh.kumar@linaro.org>
+
+description: |
+ The Arm Message Handling Unit (MHU) Version 2 is a mailbox controller that has
+ between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
+ communication with remote processor(s), where the number of channel windows
+ are implementation dependent.
+
+ Given the unidirectional nature of the controller, an MHUv2 mailbox may only
+ be written to or read from. If a pair of MHU controllers is implemented
+ between two processing elements to provide bidirectional communication, these
+ must be specified as two separate mailboxes.
+
+ If the interrupts property is present in device tree node, then its treated as
+ a "receiver" mailbox, otherwise a "sender".
+
+ An MHU controller must be specified along with the supported transport
+ protocols. The transport protocols determine the method of data transmission
+ as well as the number of provided mailbox channels.
+
+ Following are the possible transport protocols.
+
+ - Doorbell: Each transfer is made up of single bit flag, using any one of the
+ bits in a channel window. A channel window can support up to 32 doorbells
+ and the entire window shall be used in doorbell protocol. Optionally, data
+ may be transmitted through a shared memory region, wherein the MHU is used
+ strictly as an interrupt generation mechanism but that is out of the scope
+ of these bindings.
+
+ - Single-word: Each transfer is single word, using a single Channel window.
+
+ - Multi-word: Each transfer is made of two or more words, using two or more
+ channel windows.
+
+# We need a select here so we don't match all nodes with 'arm,primecell'
+select:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - arm,mhuv2-tx
+ - arm,mhuv2-rx
+ required:
+ - compatible
+
+properties:
+ compatible:
+ oneOf:
+ - description: Sender mode
+ items:
+ - const: arm,mhuv2-tx
+ - const: arm,primecell
+
+ - description: Receiver-mode
+ items:
+ - const: arm,mhuv2-rx
+ - const: arm,primecell
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ description: |
+ The MHUv2 controller always implements an interrupt in the "receiver"
+ mode, while the interrupt in the "sender" mode was not available in the
+ version MHUv2.0, but the later versions do have it.
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ maxItems: 1
+
+ arm,mhuv2-protocols:
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+ description: |
+ The MHUv2 controller may contain up to 124 channel windows (each 32-bit
+ wide). The hardware and the DT bindings allows any combination of those to
+ be used for various transport protocols.
+
+ This property allows a platform to describe how these channel windows are
+ used in various transport protocols. The entries in this property shall be
+ present as an array of tuples, where each tuple describes details about
+ one of the transport protocol being implemented over some channel
+ window(s).
+
+ The first field of a tuple signifies the transfer protocol, 0 is reserved
+ for doorbell protocol, 1 is reserved for single-word protocol and 2 is
+ reserved for multi-word protocol. Using any other value in the first field
+ of a tuple makes it invalid.
+
+ The second field of a tuple signifies the number of channel windows where
+ the protocol would be used. For doorbell protocol this field signifies the
+ number of 32-bit channel windows that implement the doorbell protocol. For
+ single-word protocol this field signifies the number of 32-bit channel
+ windows that implement separate single-word protocol mailbox channels. For
+ multi-word protocol this field signifies the number of channel windows
+ used for a multi-word protocol, it should be 2 or more.
+
+ The total number of channel windows specified here shouldn't be more than
+ the ones implemented by the platform, though one can specify lesser number
+ of windows here than what the platform implements.
+
+ mhu: mailbox@2b1f0000 {
+ ...
+
+ arm,mhuv2-protocols = <0 2>, <1 3>, <2 5>, <2 7>;
+ }
+
+ The above example defines the protocols of an ARM MHUv2 mailbox
+ controller, where a total of 17 channel windows are used. The first two
+ windows are used in doorbell protocol (64 doorbells), the next 3 windows
+ are (separately) used in single-word protocol, and the last two mailbox
+ channels are used in multi-word protocol of length 5 and 7 channel
+ windows.
+
+ minItems: 1
+ maxItems: 124
+ items:
+ items:
+ - enum: [ 0, 1, 2 ]
+ - minimum: 0
+ maximum: 124
+
+
+ '#mbox-cells':
+ description: |
+ It contains two fields, the first field represents the channel number,
+ which may be used in doorbell, single-word, or multi-word protocol, and
+ the second field (only relevant in doorbell protocol, should be 0
+ otherwise) represents the doorbell number within the 32 bit wide channel
+ window.
+
+ From the example given above for the arm,mhuv2-protocols, here is how a
+ client node can reference them.
+
+ mboxes = <&mhu 0 5>; // Mailbox channel 0, doorbell 5.
+ mboxes = <&mhu 1 7>; // Mailbox channel 1, doorbell 7.
+ mboxes = <&mhu 2 0>; // Mailbox channel 2, single-word protocol.
+ mboxes = <&mhu 4 0>; // Mailbox channel 4, single-word protocol.
+ mboxes = <&mhu 6 0>; // Mailbox channel 6, multi-word protocol with 7 windows.
+
+ const: 2
+
+if:
+ # Interrupt is compulsory for receiver
+ properties:
+ compatible:
+ contains:
+ const: arm,mhuv2-rx
+then:
+ required:
+ - interrupts
+
+required:
+ - compatible
+ - reg
+ - '#mbox-cells'
+ - arm,mhuv2-protocols
+
+additionalProperties: false
+
+examples:
+ # Multiple transport protocols implemented by the mailbox controllers
+ - |
+ soc {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ mhu_tx: mailbox@2b1f0000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhuv2-tx", "arm,primecell";
+ reg = <0 0x2b1f0000 0 0x1000>;
+ clocks = <&clock 0>;
+ clock-names = "apb_pclk";
+ interrupts = <0 45 4>;
+ arm,mhuv2-protocols = <1 5>, <2 2>, <2 5>, <2 7>, <0 2>;
+ };
+
+ mhu_rx: mailbox@2b1f1000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhuv2-rx", "arm,primecell";
+ reg = <0 0x2b1f1000 0 0x1000>;
+ clocks = <&clock 0>;
+ clock-names = "apb_pclk";
+ interrupts = <0 46 4>;
+ arm,mhuv2-protocols = <1 5>, <2 7>, <0 2>;
+ };
+
+ mhu_client: scb@2e000000 {
+ compatible = "fujitsu,mb86s70-scb-1.0";
+ reg = <0 0x2e000000 0 0x4000>;
+
+ mboxes =
+ //single-word protocol channel 0, mhu-rx
+ <&mhu_rx 0 0>,
+ //single-word protocol channel 4, mhu-tx
+ <&mhu_tx 4 0>,
+ //multi-word protocol channel 6 with 5 windows, mhu-tx
+ <&mhu_tx 6 0>,
+ //doorbell protocol channel 9, doorbell 27, mhu-tx
+ <&mhu_tx 9 27>;
+ };
+ };
--
2.25.0.rc1.19.g042ed3e048af
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH V4] dt-bindings: mailbox : arm,mhuv2: Add bindings
2020-10-13 4:32 ` Viresh Kumar
@ 2020-10-13 11:55 ` Rob Herring
-1 siblings, 0 replies; 8+ messages in thread
From: Rob Herring @ 2020-10-13 11:55 UTC (permalink / raw)
To: Viresh Kumar
Cc: Jassi Brar, morten_bp, Tushar Khandelwal, linux-arm-kernel,
Vincent Guittot, devicetree, Sudeep Holla, Frank Rowand,
linux-kernel
On Mon, Oct 12, 2020 at 11:32 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> This patch adds device tree binding for ARM Message Handling Unit (MHU)
> controller version 2.
>
> Based on earlier work by Morten Borup Petersen.
>
> Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
> Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>
> ---
> V3->V4:
> - Made interrupts property compulsory for receiver
> - Added interrupts for both nodes in example
> - Fixed min/max items for protocols property
> - Don't add -tx/rx to node's name.
>
> V2->V3:
> - compatible is changed to arm-mhuv2-tx/rx. Later version of MHUv2
> have an interrupt in the sender mode as well and we can't find if a
> mailbox is sender or receiver just based on an interrupt anymore. We
> needed a better way.
>
> - arm-mhuv2-mode is renamed to arm,mhuv2-protocols to fit the purpose
> better.
>
> - Minor formatting otherwise.
>
> Morten: Please let me know if you want me to add your signoff here from
> some other email id as you no longer work with ARM.
> ---
> .../bindings/mailbox/arm,mhuv2.yaml | 215 ++++++++++++++++++
> 1 file changed, 215 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
Reviewed-by: Rob Herring <robh@kernel.org>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH V4] dt-bindings: mailbox : arm,mhuv2: Add bindings
@ 2020-10-13 11:55 ` Rob Herring
0 siblings, 0 replies; 8+ messages in thread
From: Rob Herring @ 2020-10-13 11:55 UTC (permalink / raw)
To: Viresh Kumar
Cc: devicetree, Vincent Guittot, linux-kernel, Jassi Brar, morten_bp,
Tushar Khandelwal, Sudeep Holla, Frank Rowand, linux-arm-kernel
On Mon, Oct 12, 2020 at 11:32 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> This patch adds device tree binding for ARM Message Handling Unit (MHU)
> controller version 2.
>
> Based on earlier work by Morten Borup Petersen.
>
> Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
> Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>
> ---
> V3->V4:
> - Made interrupts property compulsory for receiver
> - Added interrupts for both nodes in example
> - Fixed min/max items for protocols property
> - Don't add -tx/rx to node's name.
>
> V2->V3:
> - compatible is changed to arm-mhuv2-tx/rx. Later version of MHUv2
> have an interrupt in the sender mode as well and we can't find if a
> mailbox is sender or receiver just based on an interrupt anymore. We
> needed a better way.
>
> - arm-mhuv2-mode is renamed to arm,mhuv2-protocols to fit the purpose
> better.
>
> - Minor formatting otherwise.
>
> Morten: Please let me know if you want me to add your signoff here from
> some other email id as you no longer work with ARM.
> ---
> .../bindings/mailbox/arm,mhuv2.yaml | 215 ++++++++++++++++++
> 1 file changed, 215 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
Reviewed-by: Rob Herring <robh@kernel.org>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-10-13 11:56 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-09 11:42 [PATCH V3] dt-bindings: mailbox: arm,mhuv2: Add bindings Viresh Kumar
2020-10-09 11:42 ` Viresh Kumar
2020-10-12 19:16 ` Rob Herring
2020-10-12 19:16 ` Rob Herring
2020-10-13 4:32 ` [PATCH V4] dt-bindings: mailbox : " Viresh Kumar
2020-10-13 4:32 ` Viresh Kumar
2020-10-13 11:55 ` Rob Herring
2020-10-13 11:55 ` Rob Herring
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