Difference between revisions of "RNG device tree configuration"

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Applicable for STM32MP13x lines, STM32MP15x lines


1 Article purpose[edit]

The purpose of this article is to explain This article explains how to configure the RNG using the device tree mechanism (DT), relying on the bindings documentation, that which is the description of the required and optional device - tree properties.

The peripheral can be assigned to different contexts /and software components, depending on the final product needs. Refer to How to assign an internal peripheral to a runtime context article for guidelines on this such configuration.

2 DT bindings documentation[edit]

The device tree binding bindings documents are stored either in the given applicable components listed below, or in the Linux® kernel repository:

3 DT configuration[edit]

This hardware description is a combination of the STM32 microprocessor device tree files (.dtsi extension) and board device tree files (.dts extension). See the Device tree for an explanation of the device - tree file organization.

STM32CubeMX can be used to generate the board device tree. Refer to How to configure the DT using STM32CubeMX for more details.

3.1 DT configuration (STM32/SoC level)[edit]

The RNG node is located in the device tree file for the software components, supporting the peripheral and listed in the above DT bindings documentation paragraph.

It is only included on SoC in SoCs supporting secure boot.

Warning white.png Warning
This device tree part is related to STM32 microprocessors. It must be kept as is, without being modified by the end-user.

3.2 DT configuration (board level)[edit]

The objective of this chapter is to explain This chapter explains how to enable and configure the RNG DT nodes for a board.

Peripheral The peripheral configuration should must be done in the specific board device tree files (board dts file).

RNG runs on two different clocks:

  • The AHB bus clock to access registers
  • a A dedicated RNG clock connected to internal random blocks.

Depending on the clock source selected for the RNG clocks, the RNG dedicated clock must be higher than AHB clock / 32 if clock error detection is enabled.

3.3 DT configuration examples[edit]

   &rng {
        status = "okay";
        clock-error-detect;      // Enable the clock error management
   };

4 How to configure the DT using STM32CubeMX[edit]

The STM32CubeMX tool can be used to configure the STM32MPU device and get the corresponding platform configuration device tree files.
STM32CubeMX may might not support all the properties described in the DT binding bindings files listed in the above DT bindings documentation paragraph. If soIn such cases, the tool inserts user sections in the generated device tree. These sections can then be edited to add some properties, and they ; They are preserved from one generation to another. Refer to STM32CubeMX user manual for further information.

5 References[edit]

Refer to the following links for additional information:



{{ApplicableFor
|MPUs list=STM32MP13x, STM32MP15x
|MPUs checklist=STM32MP13x, STM32MP15x
}}<noinclude></noinclude>


== Article purpose ==The purpose of this article is to explain This article explains how to configure the [[RNG_internal_peripheral|'''RNG''']] using the [[Device tree|device tree]] mechanism (DT), relying on the bindings documentation, thatwhich is the description of the required and optional device- tree properties.

The peripheral can be assigned to different contexts/ and software components, depending on the final product needs. Refer to [[How to assign an internal peripheral to a runtime context]] article for guidelines on thissuch configuration .

== DT bindings documentation ==

The device tree bindingbindings documents are stored either in the given applicable components listed below, or in the Linux<sup>®</sup> kernel repository: <br>


* TF-A BL2, OP-TEE, Linux<sup>&reg;</sup> Kernel:
** RNG device tree bindings : {{CodeSource | Linux kernel | Documentation/devicetree/bindings/rng/st,stm32-rng.yaml}}

== DT configuration ==
This hardware description is a combination of the '''STM32 microprocessor''' device tree files (''.dtsi'' extension) and '''board''' device tree files (''.dts'' extension). See the [[Device tree]] for an explanation of the device- tree file organization.

'''STM32CubeMX''' can be used to generate the board device tree. Refer to [[#How_to_configure_the_DT_using_STM32CubeMX|How to configure the DT using STM32CubeMX]] for more details.

===DT configuration (STM32/SoC level) ===

The [[RNG_internal_peripheral|'''RNG''']] node is located in the [[STM32 MPU device_tree#Device tree structure|device tree file]] for the software components, supporting the peripheral and listed in the above [[#DT bindings documentation|DT bindings documentation]] paragraph. 

It is only included on SoCin SoCs supporting secure boot.

{{Warning|This device tree part is related to STM32 microprocessors. It must be kept as is, without being modified by the end-user.}}

=== DT configuration (board level) ===
The objective of this chapter is to explain This chapter explains how to enable and configure the [[RNG_internal_peripheral|'''RNG''']] DT nodes for a board.<br>

Peripheral The peripheral configuration shouldmust be done in the specific board device tree files (board dts file).<br>


RNG runs on two different clocks: 
* The AHB bus clock to access registers
* aA dedicated RNG clock connected to internal random blocks.


Depending on the clock source selected for the RNG clocks, the RNG dedicated clock '''must''' be higher than AHB clock / 32 if clock error detection is enabled.

=== DT configuration examples ===

    &rng {
         status = "okay";
         clock-error-detect;     {{Highlight | // Enable the clock error management}}
    };

==How to configure the DT using STM32CubeMX==
The [[STM32CubeMX]] tool can be used to configure the STM32MPU device and get the corresponding [[Device_tree#STM32_MPU|platform configuration device tree]] files.<br />

STM32CubeMX maymight not support all the properties described in the DT bindingbindings files listed in the above [[#DT bindings documentation|DT bindings documentation]] paragraph. If soIn such cases, the tool inserts '''user sections''' in the generated device tree. These sections can then be edited to add some properties, and they ; They are preserved from one generation to another. Refer to [[STM32CubeMX]] user manual for further information.
==References==
Refer to the following links for additional information:<references />

<noinclude>

{{ArticleBasedOnModel | Peripheral or framework device tree configuration model}}

[[Category:Device tree configuration]]
[[Category:OP-TEE Crypto]]{{PublicationRequestId | 24656| 2022-09-26}}</noinclude>
(7 intermediate revisions by 3 users not shown)
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== Article purpose ==
 
== Article purpose ==
The purpose of this article is to explain how to configure the [[RNG_internal_peripheral|'''RNG''']] using the [[Device tree|device tree]] mechanism, relying on the bindings documentation, that is the description of the required and optional device-tree properties.
+
This article explains how to configure the [[RNG_internal_peripheral|'''RNG''']] using the [[Device tree|device tree]] mechanism (DT), relying on the bindings documentation, which is the description of the required and optional device tree properties.
   
The peripheral can be assigned to different contexts/software components, depending on the final product needs. Refer to [[How to assign an internal peripheral to a runtime context]] article for guidelines on this configuration .
+
The peripheral can be assigned to different contexts and software components, depending on the final product needs. Refer to [[How to assign an internal peripheral to a runtime context]] article for guidelines on such configuration.
   
 
== DT bindings documentation ==
 
== DT bindings documentation ==
   
The device tree binding documents are stored either in the given applicable components listed below, or in the Linux kernel repository: <br>
+
The device tree bindings documents are stored either in the given applicable components listed below, or in the Linux<sup>®</sup> kernel repository: <br>
   
 
* TF-A BL2, OP-TEE, Linux<sup>&reg;</sup> Kernel:
 
* TF-A BL2, OP-TEE, Linux<sup>&reg;</sup> Kernel:
** RNG device tree bindings : {{CodeSource | Linux kernel | Documentation/devicetree/bindings/rng/st,stm32-rng.yaml}}
+
** RNG device tree bindings: {{CodeSource | Linux kernel | Documentation/devicetree/bindings/rng/st,stm32-rng.yaml}}
   
 
== DT configuration ==
 
== DT configuration ==
This hardware description is a combination of the '''STM32 microprocessor''' device tree files (''.dtsi'' extension) and '''board''' device tree files (''.dts'' extension). See the [[Device tree]] for an explanation of the device-tree file organization.
+
This hardware description is a combination of the '''STM32 microprocessor''' device tree files (''.dtsi'' extension) and '''board''' device tree files (''.dts'' extension). See the [[Device tree]] for an explanation of the device tree file organization.
   
 
'''STM32CubeMX''' can be used to generate the board device tree. Refer to [[#How_to_configure_the_DT_using_STM32CubeMX|How to configure the DT using STM32CubeMX]] for more details.
 
'''STM32CubeMX''' can be used to generate the board device tree. Refer to [[#How_to_configure_the_DT_using_STM32CubeMX|How to configure the DT using STM32CubeMX]] for more details.
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The [[RNG_internal_peripheral|'''RNG''']] node is located in the [[STM32 MPU device_tree#Device tree structure|device tree file]] for the software components, supporting the peripheral and listed in the above [[#DT bindings documentation|DT bindings documentation]] paragraph.  
 
The [[RNG_internal_peripheral|'''RNG''']] node is located in the [[STM32 MPU device_tree#Device tree structure|device tree file]] for the software components, supporting the peripheral and listed in the above [[#DT bindings documentation|DT bindings documentation]] paragraph.  
   
It is only included on SoC supporting secure boot.
+
It is only included in SoCs supporting secure boot.
   
 
{{Warning|This device tree part is related to STM32 microprocessors. It must be kept as is, without being modified by the end-user.}}
 
{{Warning|This device tree part is related to STM32 microprocessors. It must be kept as is, without being modified by the end-user.}}
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=== DT configuration (board level) ===
 
=== DT configuration (board level) ===
   
The objective of this chapter is to explain how to enable and configure the [[RNG_internal_peripheral|'''RNG''']] DT nodes for a board.<br>
+
This chapter explains how to enable and configure the [[RNG_internal_peripheral|'''RNG''']] DT nodes for a board.<br>
   
Peripheral configuration should be done in specific board device tree files (board dts file).<br>
+
The peripheral configuration must be done in the specific board device tree files (board dts file).<br>
   
 
RNG runs on two different clocks:  
 
RNG runs on two different clocks:  
* AHB bus clock to access registers
+
* The AHB bus clock to access registers
* a dedicated RNG clock connected to internal random blocks.
+
* A dedicated RNG clock connected to internal random blocks
   
Depending the clock source selected for the RNG clocks, the RNG dedicated clock '''must''' be higher than AHB clock / 32 if clock error detection is enabled.
+
Depending on the clock source selected for the RNG clocks, the RNG dedicated clock '''must''' be higher than AHB clock / 32 if clock error detection is enabled.
   
 
=== DT configuration examples ===
 
=== DT configuration examples ===
Line 50: Line 50:
   
 
==How to configure the DT using STM32CubeMX==
 
==How to configure the DT using STM32CubeMX==
The [[STM32CubeMX]] tool can be used to configure the STM32MPU device and get the corresponding [[Device_tree#STM32|platform configuration device tree]] files.<br />
+
The [[STM32CubeMX]] tool can be used to configure the STM32MPU device and get the corresponding [[Device_tree#STM32_MPU|platform configuration device tree]] files.<br />
STM32CubeMX may not support all the properties described in DT binding files listed in the above [[#DT bindings documentation|DT bindings documentation]] paragraph. If so, the tool inserts '''user sections''' in the generated device tree. These sections can then be edited to add some properties, and they are preserved from one generation to another. Refer to [[STM32CubeMX]] user manual for further information.
+
STM32CubeMX might not support all the properties described in the DT bindings files listed in the above [[#DT bindings documentation|DT bindings documentation]] paragraph. In such cases, the tool inserts '''user sections''' in the generated device tree. These sections can then be edited to add some properties; They are preserved from one generation to another. Refer to [[STM32CubeMX]] user manual for further information.
 
 
==References==
 
Refer to the following links for additional information:
 
<references />
 
   
 
<noinclude>
 
<noinclude>
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[[Category:Device tree configuration]]
 
[[Category:Device tree configuration]]
 
[[Category:OP-TEE Crypto]]
 
[[Category:OP-TEE Crypto]]
  +
{{PublicationRequestId | 24656| 2022-09-26}}
 
</noinclude>
 
</noinclude>