0001 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
0002 %YAML 1.2
0003 ---
0004 $id: "http://devicetree.org/schemas/arm/stm32/st,mlahb.yaml#"
0005 $schema: "http://devicetree.org/meta-schemas/core.yaml#"
0006
0007 title: STMicroelectronics STM32 ML-AHB interconnect bindings
0008
0009 maintainers:
0010 - Fabien Dessenne <fabien.dessenne@foss.st.com>
0011 - Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
0012
0013 description: |
0014 These bindings describe the STM32 SoCs ML-AHB interconnect bus which connects
0015 a Cortex-M subsystem with dedicated memories. The MCU SRAM and RETRAM memory
0016 parts can be accessed through different addresses (see "RAM aliases" in [1])
0017 using different buses (see [2]): balancing the Cortex-M firmware accesses
0018 among those ports allows to tune the system performance.
0019 [1]: https://www.st.com/resource/en/reference_manual/dm00327659.pdf
0020 [2]: https://wiki.st.com/stm32mpu/wiki/STM32MP15_RAM_mapping
0021
0022 allOf:
0023 - $ref: /schemas/simple-bus.yaml#
0024
0025 properties:
0026 compatible:
0027 contains:
0028 enum:
0029 - st,mlahb
0030
0031 dma-ranges:
0032 description: |
0033 Describe memory addresses translation between the local CPU and the
0034 remote Cortex-M processor. Each memory region, is declared with
0035 3 parameters:
0036 - param 1: device base address (Cortex-M processor address)
0037 - param 2: physical base address (local CPU address)
0038 - param 3: size of the memory region.
0039 maxItems: 3
0040
0041 '#address-cells':
0042 const: 1
0043
0044 '#size-cells':
0045 const: 1
0046
0047 required:
0048 - compatible
0049 - '#address-cells'
0050 - '#size-cells'
0051 - dma-ranges
0052
0053 unevaluatedProperties: false
0054
0055 examples:
0056 - |
0057 mlahb: ahb@38000000 {
0058 compatible = "st,mlahb", "simple-bus";
0059 #address-cells = <1>;
0060 #size-cells = <1>;
0061 reg = <0x10000000 0x40000>;
0062 ranges;
0063 dma-ranges = <0x00000000 0x38000000 0x10000>,
0064 <0x10000000 0x10000000 0x60000>,
0065 <0x30000000 0x30000000 0x60000>;
0066
0067 m4_rproc: m4@10000000 {
0068 reg = <0x10000000 0x40000>;
0069 };
0070 };
0071
0072 ...
