ra8_io_stream_usbcdc.c File Reference

USB-CDC byte-stream sink – bulk-IN writes through ra8_usb_pal. More...

#include "ra8_io_stream_usbcdc.h"
#include <stdint.h>
#include "ra8_attributes.h"
#include "ra8_check.h"
#include "ra8_err.h"
#include "ra8_io_stream_backend.h"
#include "ra8_usb_pal.h"

Include dependency graph for ra8_io_stream_usbcdc.c:

Go to the source code of this file.

Enumerations
enum	ra8_io_usbcdc_const_t : uint32_t { k_usbcdc_max_chunk = 65535 }
	USB-CDC sink constants. More...

Functions
static ra8_err_t	internal_usbcdc_write (void *ctx, const uint8_t *buf, uint32_t len, uint32_t *out_written)
	USB-CDC sink: send all bytes through the bulk-IN endpoint.
ra8_err_t	ra8_io_stream_usbcdc_init (ra8_io_stream_t *s, ra8_io_stream_usbcdc_state_t *state, uint8_t ep_addr)
	Bind a USB-CDC stream sink into a caller-owned stream handle.

Variables
static const char *const	s_tag = "ra8_io_stream_usbcdc"
	Module log tag.
static const ra8_io_stream_iface_t	s_usbcdc_iface
	USB-CDC stream sink vtable.

Detailed Description

USB-CDC byte-stream sink – bulk-IN writes through ra8_usb_pal.

Tag

[Ring 4 / PAL] {World: NS}

Binds ra8_io_stream_iface to ra8_usb_pal_ep_send. The PAL takes a 16-bit length, so a larger write is split into 65535-byte chunks. Touches no raw MMIO – the PAL owns the USB controller access.

Copyright

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

Definition in file ra8_io_stream_usbcdc.c.

Enumeration Type Documentation

ra8_io_usbcdc_const_t

enum ra8_io_usbcdc_const_t : uint32_t

USB-CDC sink constants.

Since

0.1.0

Enumerator
k_usbcdc_max_chunk	Largest single ra8_usb_pal_ep_send length.

Definition at line 36 of file ra8_io_stream_usbcdc.c.

Function Documentation

internal_usbcdc_write()

ra8_err_t internal_usbcdc_write ( void * ctx, const uint8_t * buf, uint32_t len, uint32_t * out_written )

static

USB-CDC sink: send all bytes through the bulk-IN endpoint.

Splits the request into at most 65535-byte PAL transfers and stops at the first non-ok status, reporting how many bytes were sent.

Parameters

[in]	ctx	USB-CDC sink state (as a void cookie).
[in]	buf	Source bytes.
[in]	len	Number of bytes to send.
[out]	out_written	Sent byte count, or NULL.

Returns

ra8_err_t Error code.

Return values

k_ra8_ok	All bytes sent.
k_ra8_err_null_ptr	ctx or buf was NULL.
k_ra8_err_*	Propagated from ra8_usb_pal_ep_send.

Precondition

ctx is a populated USB-CDC sink state.

The USB device + CDC class are up.

Postcondition

On success all len bytes were queued to the endpoint.

*out_written (when provided) holds the sent count.

Note

Not thread-safe with respect to the same endpoint.

Since

0.1.0

Definition at line 67 of file ra8_io_stream_usbcdc.c.

References ra8_io_stream_usbcdc_state_t::ep_addr, k_ra8_ok, k_usbcdc_max_chunk, RA8_CHECK_NULL_PTR, ra8_usb_pal_ep_send(), and s_tag.

ra8_io_stream_usbcdc_init()

ra8_err_t ra8_io_stream_usbcdc_init ( ra8_io_stream_t * s, ra8_io_stream_usbcdc_state_t * state, uint8_t ep_addr )

nodiscard

Bind a USB-CDC stream sink into a caller-owned stream handle.

Parameters

[out]	s	Stream handle to bind (zero-initialised by the caller).
[out]	state	Caller-owned sink state to populate.
[in]	ep_addr	USB bulk-IN endpoint address to write to.

Returns

ra8_err_t Error code.

Return values

k_ra8_ok	Sink bound; s is usable.
k_ra8_err_null_ptr	s or state was NULL.

Precondition

The USB device stack + CDC class are up and ep_addr is configured.

s and state out-live every call made through the stream.

Postcondition

On success s sends bytes through ep_addr.

On any non-ok return s and state are left unbound/untouched.

Note

Not thread-safe with respect to the same stream.

Since

0.1.0

Definition at line 100 of file ra8_io_stream_usbcdc.c.

References ra8_io_stream_usbcdc_state_t::ep_addr, RA8_CHECK_NULL_PTR, ra8_io_stream_bind(), s_tag, and s_usbcdc_iface.

Variable Documentation

s_tag

const char* const s_tag = "ra8_io_stream_usbcdc"

static

Module log tag.

Definition at line 28 of file ra8_io_stream_usbcdc.c.

s_usbcdc_iface

const ra8_io_stream_iface_t s_usbcdc_iface

static

Initial value:

                                                  = {
  .write = internal_usbcdc_write,
  .flush = nullptr,
}

USB-CDC stream sink vtable.

flush is NULL: the PAL queues directly.

Definition at line 94 of file ra8_io_stream_usbcdc.c.

Referenced by ra8_io_stream_usbcdc_init().