1# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) 2%YAML 1.2 3--- 4$id: "http://devicetree.org/schemas/arm/stm32/st,mlahb.yaml#" 5$schema: "http://devicetree.org/meta-schemas/core.yaml#" 6 7title: STMicroelectronics STM32 ML-AHB interconnect 8 9maintainers: 10 - Fabien Dessenne <fabien.dessenne@foss.st.com> 11 - Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> 12 13description: | 14 These bindings describe the STM32 SoCs ML-AHB interconnect bus which connects 15 a Cortex-M subsystem with dedicated memories. The MCU SRAM and RETRAM memory 16 parts can be accessed through different addresses (see "RAM aliases" in [1]) 17 using different buses (see [2]): balancing the Cortex-M firmware accesses 18 among those ports allows to tune the system performance. 19 [1]: https://www.st.com/resource/en/reference_manual/dm00327659.pdf 20 [2]: https://wiki.st.com/stm32mpu/wiki/STM32MP15_RAM_mapping 21 22allOf: 23 - $ref: /schemas/simple-bus.yaml# 24 25properties: 26 compatible: 27 contains: 28 enum: 29 - st,mlahb 30 31 dma-ranges: 32 description: | 33 Describe memory addresses translation between the local CPU and the 34 remote Cortex-M processor. Each memory region, is declared with 35 3 parameters: 36 - param 1: device base address (Cortex-M processor address) 37 - param 2: physical base address (local CPU address) 38 - param 3: size of the memory region. 39 maxItems: 3 40 41 '#address-cells': 42 const: 1 43 44 '#size-cells': 45 const: 1 46 47required: 48 - compatible 49 - '#address-cells' 50 - '#size-cells' 51 - dma-ranges 52 53unevaluatedProperties: false 54 55examples: 56 - | 57 mlahb: ahb@38000000 { 58 compatible = "st,mlahb", "simple-bus"; 59 #address-cells = <1>; 60 #size-cells = <1>; 61 reg = <0x10000000 0x40000>; 62 ranges; 63 dma-ranges = <0x00000000 0x38000000 0x10000>, 64 <0x10000000 0x10000000 0x60000>, 65 <0x30000000 0x30000000 0x60000>; 66 67 m4_rproc: m4@10000000 { 68 reg = <0x10000000 0x40000>; 69 }; 70 }; 71 72... 73