Device bindings

Table of Contents

• homecore,console-led
• homecore,gpio-led
• homecore,ramdisk
• st,stm32-usart
• st,stm32f1-gpio
• st,stm32f4-gpio
• ti,stellaris-uart

Every compatible a device description can use, generated from the bindings.

Generated by scripts/bindings_doc.py from src/drivers/<class>/<compatible>.yaml and the board descriptions when the documentation is built. How bindings, properties, and capabilities work is described in Drivers.

Compatible	Driver	Summary
homecore,console-led	console_led	LED stand-in for emulators without LEDs; prints "[ledN] on" or "[ledN] off" on each change request.
homecore,gpio-led	gpio_led	LED driven by a GPIO output pin, with a readable and writable /dev file.
homecore,ramdisk	ramdisk	Block device backed by a RAM buffer allocated at build time; contents are lost at reset.
st,stm32-usart	stm32_usart	STM32 USART, 8N1, interrupt-driven receive, polled transmit. Board code enables its clock and pins.
st,stm32f1-gpio	stm32f1_gpio	STM32F1 GPIO port with 16 pins; the driver enables the port clock.
st,stm32f4-gpio	stm32f4_gpio	STM32F4 GPIO port with 16 pins; the driver enables the port clock.
ti,stellaris-uart	stellaris_uart	Stellaris UART, interrupt-driven receive, polled transmit, reset line configuration (QEMU).

homecore,console-led

LED stand-in for emulators without LEDs; prints "[ledN] on" or "[ledN] off" on each change request.

Driver prefix	console_led
Sources	src/drivers/led/console_led.c
Binding	src/drivers/led/homecore,console-led.yaml
Guide	LEDs
Provides	LED: exports <driver>_led_ops; numbered in dt_led_table

Property	Type	Required	Default	Constraints	C field	Description
devname	devpath	no	the node name	unique /dev name	path	Device file name under /dev; defaults to the node name.

Enabled by: lm3s6965evb (led0); stm32vldiscovery + qemu.yaml (qemu_led0, qemu_led1)

homecore,gpio-led

LED driven by a GPIO output pin, with a readable and writable /dev file.

Driver prefix	gpio_led
Sources	src/drivers/led/gpio_led.c
Binding	src/drivers/led/homecore,gpio-led.yaml
Guide	LEDs
Provides	LED: exports <driver>_led_ops; numbered in dt_led_table

Property	Type	Required	Default	Constraints	C field	Description
gpio	gpio	yes	—	—	port	Enabled GPIO port device driving the LED, such as gpiod.
pin	int	yes	—	at most 15, unique per gpio	pin	Pin number within the port; one LED per pin.
active-low	bool	no	false	—	active_low	The LED lights when the pin is low.
devname	devpath	no	the node name	unique /dev name	path	Device file name under /dev; defaults to the node name.

Enabled by: stm32f4discovery (led0, led1, led2, led3); stm32vldiscovery (led0, led1)

homecore,ramdisk

Block device backed by a RAM buffer allocated at build time; contents are lost at reset.

Driver prefix	ramdisk
Sources	src/drivers/block/ramdisk.c
Binding	src/drivers/block/homecore,ramdisk.yaml
Guide	Block devices
Provides	Block device: exports <driver>_block_ops; mounts can name it

Property	Type	Required	Default	Constraints	C field	Description
size	size	yes	—	at least 512, multiple of 512, allocates a .bss buffer (field data)	size	Disk size in bytes, such as 64K; a multiple of 512. The buffer is placed in .bss.

Enabled by: lm3s6965evb (ram0); stm32f4discovery (ram0, ram1)

st,stm32-usart

STM32 USART, 8N1, interrupt-driven receive, polled transmit. Board code enables its clock and pins.

Driver prefix	stm32_usart
Sources	src/drivers/serial/stm32_usart.c
Binding	src/drivers/serial/st,stm32-usart.yaml
Guide	Serial ports
Provides	Can be chosen.console: exports <driver>_console_ops Handles its interrupt: <driver>_isr() is called by dt_irq_dispatch()

Property	Type	Required	Default	Constraints	C field	Description
reg	int	yes	—	unique	base	Register block address.
irq	int	yes	—	unique	irq	NVIC interrupt number of the receive interrupt.
bus	clock	yes	—	—	clock_hz	Bus clock name, resolved through the board's clocks map.
baud	int	no	115200	at least 1	baud	Line rate in bits per second.
devname	devpath	no	the node name	unique /dev name	path	VFS name under /dev; defaults to the node name.

Enabled by: stm32f4discovery (usart2); stm32vldiscovery (usart1); stm32vldiscovery + qemu.yaml (usart1)

st,stm32f1-gpio

STM32F1 GPIO port with 16 pins; the driver enables the port clock.

Driver prefix	stm32f1_gpio
Sources	src/drivers/gpio/stm32f1_gpio.c
Binding	src/drivers/gpio/st,stm32f1-gpio.yaml
Guide	GPIO ports
Provides	GPIO port: exports <driver>_gpio_ops; gpio properties can name it

Property	Type	Required	Default	Constraints	C field	Description
reg	int	yes	—	unique	base	Register block address.
clock-bit	int	yes	—	at most 31	clock_bit	The port's enable bit in RCC_APB2ENR (IOPAEN, GPIOA, is 2).

Enabled by: stm32vldiscovery (gpioc)

st,stm32f4-gpio

STM32F4 GPIO port with 16 pins; the driver enables the port clock.

Driver prefix	stm32f4_gpio
Sources	src/drivers/gpio/stm32f4_gpio.c
Binding	src/drivers/gpio/st,stm32f4-gpio.yaml
Guide	GPIO ports
Provides	GPIO port: exports <driver>_gpio_ops; gpio properties can name it

Property	Type	Required	Default	Constraints	C field	Description
reg	int	yes	—	unique	base	Register block address.
clock-bit	int	yes	—	at most 31	clock_bit	The port's enable bit in RCC_AHB1ENR (GPIOA is 0).

Enabled by: stm32f4discovery (gpiod)

ti,stellaris-uart

Stellaris UART, interrupt-driven receive, polled transmit, reset line configuration (QEMU).

Driver prefix	stellaris_uart
Sources	src/drivers/serial/stellaris_uart.c
Binding	src/drivers/serial/ti,stellaris-uart.yaml
Guide	Serial ports
Provides	Can be chosen.console: exports <driver>_console_ops Handles its interrupt: <driver>_isr() is called by dt_irq_dispatch()

Property	Type	Required	Default	Constraints	C field	Description
reg	int	yes	—	unique	base	Register block address.
irq	int	yes	—	unique	irq	NVIC interrupt number of the receive interrupt.
devname	devpath	no	the node name	unique /dev name	path	VFS name under /dev; defaults to the node name.

Enabled by: lm3s6965evb (uart0, uart1, uart2)