1. Article purpose[edit source]
This article explains how to configure the GPU internal peripheral when it is assigned to the Linux® OS.
The configuration is performed using the device tree mechanism that provides a hardware description of the GPU internal peripheral, used by the STM32 GPU Linux driver.
2. DT bindings documentation[edit source]
The GPU is represented by the STM32 GPU device tree bindings [1].
3. DT configuration[edit source]
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 split.
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 level)[edit source]
The GPU device tree node is declared in stm32mp157c.dtsi [2]. The declaration (shown below) defines the hardware registers base address, the interrupt, the clocks and the reset.
gpu: gpu@59000000 {
compatible = "vivante,gc";
reg = <0x59000000 0x800>;
interrupts = <GIC_SPI 109 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&rcc GPU>, <&rcc GPU_K>;
clock-names = "bus" ,"core";
resets = <&rcc GPU_R>;
status = "disabled";
};
4. How to configure the DT using STM32CubeMX[edit source]
The STM32CubeMX tool can be used to configure the STM32MPU device and get the corresponding platform configuration device tree files.
The STM32CubeMX may not support all the properties described in the above 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.
5. References[edit source]