keychron_qmk_firmware/usb_extra.c

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#include <avr/interrupt.h>
#include "usb_extra.h"
int8_t usb_extra_send(uint8_t report_id, uint8_t bits)
{
uint8_t intr_state, timeout;
if (!usb_configured()) return -1;
intr_state = SREG;
cli();
UENUM = EXTRA_ENDPOINT;
timeout = UDFNUML + 50;
while (1) {
// are we ready to transmit?
if (UEINTX & (1<<RWAL)) break;
SREG = intr_state;
// has the USB gone offline?
if (!usb_configured()) return -1;
// have we waited too long?
if (UDFNUML == timeout) return -1;
// get ready to try checking again
intr_state = SREG;
cli();
UENUM = EXTRA_ENDPOINT;
}
UEDATX = report_id;
UEDATX = bits;
UEINTX = 0x3A;
SREG = intr_state;
return 0;
}
int8_t usb_extra_audio_send(uint8_t bits)
{
return usb_extra_send(1, bits);
}
int8_t usb_extra_system_send(uint8_t bits)
{
return usb_extra_send(2, bits);
}