rz_device_tree_templates

A collection of Device Tree templates to be used as starting points

Overview

This document describes the device tree source ('.dts') file for a custom board based on the Renesas RZ/G2L SoC. The device tree defines the hardware configuration of the board, including memory, peripherals, Ethernet, USB and pin assignments.

Hardware Features

Core Components

• SOC: Renesas R9A07G044 (RZ/G2L)
• Memory: Defines the system memory region. 'reg' must accurately reflect your DRAM configuration (address and size)
• reserved memory: Contiguous Memory Allocator reserved at 0x58000000
• Clock: 24MHz external clock (EXTAL)

Communication Interfaces

• Serial Console: SCIFO configured at 115200 baud (8N1)
• Ethernet: Gigabit Ethernet (RGMII)
• I2C: I2C1 interface enabled
• Display: MIPI-DSI (4 lanes) with ADV7535 HDMI bridge
• HDMI Output: Type-D connector
• USB:
  • USB0: OTG mode (host/device capable)
  • USB1: Host-only mode
  • Both controllers support USB2.0 (EHCI) and USB 1.1 (OHCI)
• Storage:
  • eMMC: eMMC interface. Sets power supplies, bus width and other properties.
  • SD Card: SD card interface. Sets power supplies, bus width and card detect.
• Power Supplies: The board includes several fixed voltage regulators:
  • reg_1p1v: core voltage (1.1V)
  • reg_1p8v: 1.8V rail
  • reg_3p3V: 3.3V rail
  • vccq_sdhi1: Adjustable VccQ voltage for SD card (1.8V/3.3V)
  • usb0_vbud_otg: Regulator for USB OTG
• Timers:
  • Watchdog Timer: Enables the watchdog timer with a timeout of 60 Seconds
  • Operating System Timers: Enables operating system timers

Pin Configurations

The device tree configures pins for the following interfaces:

• SCIF0: TxD (38,0), RxD (38,1)
• eMMC: 8-bit data, clock, command, reset (all at 1.8V)
• SD Card: 4-bit data, clock, command (switchable 1.8V/3.3V), card detect (19,0)
• I2C1: SDA, SCL with input enabled
• Ethernet: RGMII interface with MDC, MDIO, TX/RX pins (1.8V)
• USB0: VBUS (4,0), OVC (5,0), OTG_ID (5,1)
• USB1: VBUS (42,0), OVC (42,1)

Device Aliases

The following device aliases are configured:

• serial0 : SCIF0 (/dev/ttySC0)
• i2c1 : I2C1 controller
• mmc0 : SDHI0 (eMMC, /dev/mmcblk0)
• mmc1 : SDHI1 (SD card, /dev/mmcblk1)
• ethernet0 : eth0 (Ethernet controller)

Important Considearions:

Board Identification:

• Update the "compatible" property with your company and board name
• Keep "renesas,r9a07g044" in the compatible string for driver compatibility

Memory Configuration:

• Verify and adjust the memory size according to your board's RAM configuration
• The CMA size (256MB) can be adjusted based on your application needs

Storage Configuration:

• Uncomment mmc-hs200-1_8v in the eMMC node if your board supports HS200 mode
• Uncomment sd-uhs-sdr50 and sd-uhs-sdr104 in the SD card node if UHS modes are supported

Display Configuration:

• The MIPI-DSI to HDMI bridge (ADV7535) is configured for 4-lane operation
• HDMI connector is configured as type D (micro HDMI)

Building the Device Tree:

• Add your sample device tree file into the Device Tree source directory arch/arm64/boot/dts/renesas
• Add your sample device file in Makefile located in arch/arm64/boot/dts/renesas/Makefile to build the Device Tree Blub (DTB)
• follow instruction here https://confluence.renesas.com/display/REN/Yocto+Information#YoctoInformation-BuildDTBonlywithYocto to build DTB
• Copy the built DTB yo your boot medium or the appropriate location where your bootloader expects to find it