USB-I2C/firmware/usb.h

/* Minimal polled USB CDC-ACM device stack for ATmega8U2 (no LUFA, no interrupts) */
#ifndef USB_H
#define USB_H

#include <stdint.h>
#include <stdbool.h>

#define USB_PACKET 64

void    usb_init(void);
void    usb_task(void);              /* call often: reset + EP0 handling   */
bool    usb_ready(void);             /* true once host configured device   */
uint8_t usb_rx(uint8_t *buf);        /* copy one OUT packet (<=64B), 0=none */
void    usb_tx(const uint8_t *buf, uint8_t n);  /* send one IN packet (<=64B), drops on timeout */

/* EP0 helpers for vendor requests (data stage may span several 32 B packets) */
#define EP0_SIZE 32
bool    ep0_wait(uint8_t mask);
void    ep0_stall(void);
void    ep0_status_in(void);         /* finish an OUT/no-data request */
void    ep0_status_out(void);        /* finish an IN request */
void    ep0_send(const void *p, uint16_t len, uint16_t wlen, bool pgm);  /* whole IN request */
uint8_t ep0_rx(uint8_t *buf);        /* next OUT data packet, 0xFF on abort/timeout */
bool    ep0_tx(const uint8_t *buf, uint8_t n);  /* next IN data packet, false on abort */

/* implemented by the application */
void    usb_vendor_request(uint8_t bmRT, uint8_t bReq, uint16_t wValue, uint16_t wIndex, uint16_t wLength);
void    usb_reset_hook(void);        /* USB bus reset seen */

#endif