usb.h File Reference

STM32G4 USB full-speed device API. More...

#include <stdint.h>

Include dependency graph for usb.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	PHAL_USB_TransferEvent_t
struct	PHAL_USB_Event_t

Enumerations
enum	PHAL_USB_EndpointDirection_t : uint8_t { PHAL_USB_ENDPOINT_DIRECTION_OUT = 0U , PHAL_USB_ENDPOINT_DIRECTION_IN = 1U }

Functions
void	PHAL_USB_callback (const PHAL_USB_Event_t *event)
	Handle USB events.
bool	PHAL_USB_init (void)
	Initialize the USB device hardware and endpoints.
bool	PHAL_USB_deinit (void)
	Detach and disable the USB peripheral.
bool	PHAL_USB_connect (void)
	Attach the initialized USB device to the host.
bool	PHAL_USB_setAddress (uint8_t address)
	Apply the address assigned by a SET_ADDRESS request.
bool	PHAL_USB_stall (uint8_t endpoint, PHAL_USB_EndpointDirection_t direction)
	Stall one endpoint direction.
bool	PHAL_USB_write (uint8_t endpoint, const void *source, uint16_t length_bytes)
	Queue one device-to-host packet.
bool	PHAL_USB_read (uint8_t endpoint, void *destination, uint16_t destination_capacity, uint16_t *received_length)
	Consume one host-to-device packet.
uint16_t	PHAL_USB_getFrameNumber (void)
	Read the USB peripheral's current 11-bit frame number.

Variables
static constexpr uint8_t	PHAL_USB_CONTROL_ENDPOINT = 0U
static constexpr uint8_t	PHAL_USB_DATA_ENDPOINT = 1U
static constexpr uint16_t	PHAL_USB_PACKET_SIZE_BYTES = 64U

Detailed Description

STM32G4 USB full-speed device API.

Author

Ronak Jain (jain7.nosp@m.17@p.nosp@m.urdue.nosp@m..edu)

The HAL provides one control endpoint and one bulk data endpoint. Applications supply USB descriptors, control-request handling, and data queues through the callback and packet-transfer functions below.

Enumeration Type Documentation

PHAL_USB_EndpointDirection_t

enum PHAL_USB_EndpointDirection_t : uint8_t

USB-standard transfer direction, named from the host perspective.

Enumerator
PHAL_USB_ENDPOINT_DIRECTION_OUT	Host to device.
PHAL_USB_ENDPOINT_DIRECTION_IN	Device to host.

Function Documentation

PHAL_USB_callback()

void PHAL_USB_callback

(

const PHAL_USB_Event_t *

event

)

Handle USB events.

Applications define this callback to process bus resets, SETUP packets, OUT packets, and IN completions. Check event->transfer before accessing transfer_data. The HAL provides a weak empty implementation. OUT data remains available through PHAL_USB_read(). An IN completion marks the endpoint ready for PHAL_USB_write().

Parameters

event

USB event for the current interrupt.

Here is the caller graph for this function:

PHAL_USB_connect()

bool PHAL_USB_connect

(

void

)

Attach the initialized USB device to the host.

Returns

true when the D+ pull-up is enabled; false when USB is inactive.

Here is the call graph for this function:

PHAL_USB_deinit()

bool PHAL_USB_deinit

(

void

)

Detach and disable the USB peripheral.

Returns

true when deinitialization completes; false when USB is inactive.

Here is the call graph for this function:

PHAL_USB_getFrameNumber()

uint16_t PHAL_USB_getFrameNumber

(

void

)

Read the USB peripheral's current 11-bit frame number.

The value is maintained by the peripheral from Start-of-Frame packets and wraps after 2047.

Returns

The current frame number.

Here is the call graph for this function:

PHAL_USB_init()

bool PHAL_USB_init

(

void

)

Initialize the USB device hardware and endpoints.

Initialization enables HSI48, USB, UCPD1, PA8/PA9 USB-C sink signaling, PA11/PA12 USB data signaling, USB packet memory, endpoint zero as control, endpoint one as bulk, and USB interrupts. The device remains detached until PHAL_USB_connect() enables the D+ pull-up.

Returns

true when initialization completes; false when USB is active or the 48 MHz clock startup times out.

Here is the call graph for this function:

PHAL_USB_read()

bool PHAL_USB_read	(	uint8_t	endpoint,
		void *	destination,
		uint16_t	destination_capacity,
		uint16_t *	received_length )

Consume one host-to-device packet.

A successful read copies the packet and rearms reception. An undersized destination leaves the packet pending and reports its length through received_length. A zero-length packet accepts a null destination.

Parameters

endpoint	PHAL_USB_CONTROL_ENDPOINT or PHAL_USB_DATA_ENDPOINT.
destination	Packet destination, or null for zero capacity.
destination_capacity	Destination capacity in bytes.
received_length	Receives the packet length.

Returns

true when the packet is consumed; false when a precondition fails, reception is pending, or the destination capacity is insufficient.

Here is the call graph for this function:

PHAL_USB_setAddress()

bool PHAL_USB_setAddress

(

uint8_t

address

)

Apply the address assigned by a SET_ADDRESS request.

Apply the address after the control endpoint reports completion of the IN status packet.

Parameters

address

Device address from 0 through 127.

Returns

true when the address is applied; false for an inactive peripheral or an address above 127.

Here is the call graph for this function:

PHAL_USB_stall()

bool PHAL_USB_stall	(	uint8_t	endpoint,
		PHAL_USB_EndpointDirection_t	direction )

Stall one endpoint direction.

Parameters

endpoint	PHAL_USB_CONTROL_ENDPOINT or PHAL_USB_DATA_ENDPOINT.
direction	Endpoint direction.

Returns

true when the endpoint is stalled; false when a precondition fails.

Here is the call graph for this function:

PHAL_USB_write()

bool PHAL_USB_write	(	uint8_t	endpoint,
		const void *	source,
		uint16_t	length_bytes )

Queue one device-to-host packet.

The HAL copies exactly length_bytes into USB packet memory, where length_bytes may be zero through PHAL_USB_PACKET_SIZE_BYTES. A zero-length packet accepts a null source. The endpoint is ready for its next packet when the IN completion callback runs.

Parameters

endpoint	PHAL_USB_CONTROL_ENDPOINT or PHAL_USB_DATA_ENDPOINT.
source	Packet bytes, or null for a zero-length packet.
length_bytes	Packet length from 0 through 64.

Returns

true when the packet is queued; false when a precondition fails or the endpoint is busy.

Here is the call graph for this function:

Variable Documentation

PHAL_USB_CONTROL_ENDPOINT

uint8_t PHAL_USB_CONTROL_ENDPOINT = 0U

staticconstexpr

Endpoint zero for enumeration and control transfers.

PHAL_USB_DATA_ENDPOINT

uint8_t PHAL_USB_DATA_ENDPOINT = 1U

staticconstexpr

Endpoint one for aggregate bulk application data.

PHAL_USB_PACKET_SIZE_BYTES

uint16_t PHAL_USB_PACKET_SIZE_BYTES = 64U

staticconstexpr

Maximum packet size for both endpoints.