Injected I2C-bus seam consumed by Ring-3 I2C device drivers. More...

#include <stdint.h>
#include "ra8_err.h"

Include dependency graph for ra8_i2c_bus_ops.h:

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Data Structures
struct	ra8_i2c_bus_ops_t
	Caller-filled I2C controller-transfer seam (write / read / write-then-read). More...

Detailed Description

Injected I2C-bus seam consumed by Ring-3 I2C device drivers.

Tag: [Ring 3 / HAL] {World: NS}

The RA8D2 implements I2C twice: the classic RIIC block (ra8_i2c.h, three channels) and the I3C block's I2C-compatibility mode (ra8_i3c.h, one channel). Device drivers at [Ring 3 / HAL] (the GT911 touch driver in ra8_touch.h, the SMBus 3.2 layer in ra8_smbus.h) must not care which of the two electrically-equivalent peripherals a board revision wires their device to, so they take this small function-pointer seam in their config instead of naming ra8_i2c_* or ra8_i3c_* directly.

The seam deliberately lives at Ring 3, NOT in the ra8_io fabric: the peripheral-agnostic bus facade ra8_io_i2c_bus.h sits at [Ring 4 / PAL], and a Ring-3 driver depending on it would invert ring ordering (see docs/RING_AND_WORLD.md and the identical ra8_vsource / ra8_io_blockdev split). The sanctioned bridge is the Ring-4 adapter ra8_io_i2c_bus_as_ops(), which fills this struct with trampolines into a bound ra8_io_i2c_bus_t; the app owns the bus, binds a backend, and hands the filled seam to the device driver's _init()/_open() cfg.

The seam is transfer-only by design: bus bring-up (peripheral init, bit-rate) and teardown are the app's responsibility, because only the app knows which peripheral the board wires to the device and which other devices share that bus.

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: 0.1.0

Definition in file ra8_i2c_bus_ops.h.

Data Structures

Detailed Description