capi

The Common API (CAPI): a portable hardware abstraction layer for ADI software projects, and the SDK that builds applications against it.

An interface is one header, inc/capi_<name>.h, describing what a driver must provide. src/capi_<name>.c is the thin dispatch layer over it. A platform package implements the interfaces for one vendor's silicon; an application names the platform it wants and is built by the SDK.

Interfaces

Interface
adc	analog-to-digital converter
alloc	allocation hooks a platform overrides
can	CAN bus
clk	clock tree and rates
coprocessor	coprocessor lifecycle
dac	digital-to-analog converter
dma	DMA controller
eth_mac	Ethernet MAC
eth_phy	Ethernet PHY
gpio	general-purpose I/O
i2c	I2C controller and target
i2s	I2S audio
i3c	I3C controller
io	memory-mapped register access (macros, no dispatch layer)
irq	interrupt controller
log	log output a platform supplies
mailbox	inter-core mailbox
mdio	MDIO bus
mutex	mutual exclusion
pinctrl	pin multiplexing
platform	init, clocks and the tick hooks a platform supplies
regulator	voltage regulator
rtc	real-time clock
sem	semaphores
spi	SPI controller
time	delays and monotonic time
timer	hardware timers
uart	UART, and the stdio backend behind printf()
wdt	watchdog timer

capi/module.yml is the catalog: its interfaces: list is what a module.yml may name, and the SDK's schemas are generated from it.

Platform packages

Package
capi-maxim	Maxim platform backend
capi-alif	Alif platform backend
capi-stm32	STM32 platform backend

Each package's own README lists the parts and boards it covers, and its PLATFORM key is the one an application names under depends.platform.

Using it

An application's own module.yml names the capi it was written against and the platforms it can target:

name: hello_capi
type: application
version: "0.9.0"
capi_version_requirement: ">=0.9.0"

depends:
  platform:
    maxim: {git: "https://github.com/analogdevicesinc/capi-maxim.git", checkout: main}
    alif:  {git: "https://github.com/analogdevicesinc/capi-alif.git", checkout: main}

Its CMakeLists.txt hands the rest to the SDK:

include("${CAPI_DIR}/sdk/cmake/capi_create_application.cmake")
capi_resolve_platform()            # must precede project()
project(hello_capi LANGUAGES C ASM)
capi_create_application(hello_capi SOURCES src/main.c)

PLATFORM and BOARD come from the active CMakePresets.json preset, and only the selected platform is resolved. See capi-hello-world for a complete application, and docs/module-yml.md for the manifest format.

Versioning

Every module states which capi it is written against, as a version constraint, and the build refuses to configure if the capi it resolves does not satisfy it:

capi_version_requirement: ">=0.9.0"

A constraint is one comparison (>=, <=, =, >, <) against X.Y.Z, or a comma-joined range such as ">=0.9.0,<1.0.0". The same grammar applies to a depends entry's version:; see docs/module-yml.md.

License

BSD-3-Clause. See LICENSE.