ra8_i2c_bus_ops_t Struct Reference

Caller-filled I2C controller-transfer seam (write / read / write-then-read). More...

#include <ra8_i2c_bus_ops.h>

Data Fields
ra8_err_t(*	write )(void *ctx, uint8_t addr, const uint8_t *data, uint32_t len, bool send_stop)
	Controller write of len bytes to 7-bit address addr.
ra8_err_t(*	read )(void *ctx, uint8_t addr, uint8_t *data, uint32_t len)
	Controller read of len bytes from 7-bit address addr.
ra8_err_t(*	transfer )(void *ctx, uint8_t addr, const uint8_t *wr, uint32_t wr_len, uint8_t *rd, uint32_t rd_len)
	Combined write-then-RESTART-then-read in one transaction.
void *	ctx
	Opaque cookie handed to every callback (binder-owned).

Detailed Description

Caller-filled I2C controller-transfer seam (write / read / write-then-read).

A device driver stores this struct by value from its config and routes every bus transaction through the three callbacks. The ctx cookie is opaque to the driver; the binder that filled the seam decides what it points at (the Ring-4 ra8_io_i2c_bus_as_ops() points it at the bound ra8_io_i2c_bus_t handle, which must therefore out-live the driver). Tests may fill the seam directly with local trampolines.

Invariant

write, read, and transfer are non-NULL once filled.

Whatever ctx references out-lives every callback call.

Example:

ra8_io_i2c_bus_t bus = {};
(void)ra8_io_i2c_bus_bind_i3c_compat(&bus, 0U);
ra8_i2c_bus_ops_t ops = {};
(void)ra8_io_i2c_bus_as_ops(&bus, &ops);
ra8_touch_cfg_t cfg = { .bus = ops, ... };

See also

ra8_io_i2c_bus_as_ops Ring-4 binder over the ra8_io I2C facade.

ra8_touch_cfg_t Ring-3 consumer (GT911 touch driver).

ra8_smbus_cfg_t Ring-3 consumer (SMBus 3.2 layer).

Since

0.1.0

Definition at line 78 of file ra8_i2c_bus_ops.h.

Field Documentation

ctx

void* ra8_i2c_bus_ops_t::ctx

Opaque cookie handed to every callback (binder-owned).

Definition at line 138 of file ra8_i2c_bus_ops.h.

Referenced by ra8_io_i2c_bus_as_ops().

read

ra8_err_t(* ra8_i2c_bus_ops_t::read) (void *ctx, uint8_t addr, uint8_t *data, uint32_t len)

Controller read of len bytes from 7-bit address addr.

Issues START, the address byte with R/W# = 1, drains len bytes, then issues STOP and releases the bus.

Parameters

[in]	ctx	Binder-owned cookie (the ctx member below).
[in]	addr	7-bit peripheral address.
[out]	data	Destination buffer (non-NULL).
[in]	len	Byte count (non-zero).

Returns

ra8_err_t forwarded from the bound transport.

Definition at line 112 of file ra8_i2c_bus_ops.h.

Referenced by ra8_io_i2c_bus_as_ops(), and ra8_smbus_init().

transfer

ra8_err_t(* ra8_i2c_bus_ops_t::transfer) (void *ctx, uint8_t addr, const uint8_t *wr, uint32_t wr_len, uint8_t *rd, uint32_t rd_len)

Combined write-then-RESTART-then-read in one transaction.

The classic "address a register, read its contents" shape: writes wr_len bytes, injects a repeated START, reads rd_len bytes, then issues STOP. Matches ra8_i2c_transfer / ra8_i3c_transfer.

Parameters

[in]	ctx	Binder-owned cookie (the ctx member below).
[in]	addr	7-bit peripheral address.
[in]	wr	Bytes to send first (NULL only when wr_len 0).
[in]	wr_len	Number of bytes to send.
[out]	rd	Destination buffer (NULL only when rd_len 0).
[in]	rd_len	Number of bytes to read.

Returns

ra8_err_t forwarded from the bound transport.

Definition at line 131 of file ra8_i2c_bus_ops.h.

Referenced by internal_validate_cfg(), ra8_io_i2c_bus_as_ops(), and ra8_smbus_init().

write

ra8_err_t(* ra8_i2c_bus_ops_t::write) (void *ctx, uint8_t addr, const uint8_t *data, uint32_t len, bool send_stop)

Controller write of len bytes to 7-bit address addr.

When send_stop is true the transaction ends with STOP and the bus is released; when false the bus is held so the next call on the same bus injects a repeated-START. Matches the ra8_i2c_write contract (ra8_i3c_write uses the inverted restart flag; binders adapt).

Parameters

[in]	ctx	Binder-owned cookie (the ctx member below).
[in]	addr	7-bit peripheral address.
[in]	data	Bytes to send (non-NULL when len > 0).
[in]	len	Byte count.
[in]	send_stop	true = STOP after the payload; false = hold.

Returns

ra8_err_t forwarded from the bound transport.

Definition at line 96 of file ra8_i2c_bus_ops.h.

Referenced by internal_validate_cfg(), ra8_io_i2c_bus_as_ops(), and ra8_smbus_init().

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The documentation for this struct was generated from the following file:

• libs/ra8_hal/inc/ra8_i2c_bus_ops.h