/*!
* \brief Perform TWI control functions.
*
* This function is only available on ATmega128 systems.
*
* \param req Requested control function. May be set to one of the
* following constants:
* - TWI_SETSPEED, if conf points to an u_long value containing the bitrate.
* - TWI_GETSPEED, if conf points to an u_long value receiving the current bitrate.
* \param conf Points to a buffer that contains any data required for
* the given control function or receives data from that
* function.
* \return 0 on success, -1 otherwise.
*
* \note Timeout is limited to the granularity of the system timer.
*
*/
int TwIOCtl(int req, void *conf)
{
#ifndef __AVR_ENHANCED__
return -1;
#else
int rc = 0;
u_long lval;
switch (req) {
case TWI_SETSLAVEADDRESS:
TWAR = (*((u_char *) conf) << 1) | 1;
break;
case TWI_GETSLAVEADDRESS:
*((u_char *) conf) = TWAR;
break;
case TWI_SETSPEED:
lval = ((2UL * NutGetCpuClock() / (*((u_long *) conf)) + 1UL) / 2UL - 16UL) / 2UL;
if (lval > 1020UL) {
lval /= 16UL;
sbi(TWSR, TWPS1);
} else {
cbi(TWSR, TWPS1);
}
if (lval > 255UL) {
lval /= 4UL;
sbi(TWSR, TWPS0);
} else {
cbi(TWSR, TWPS0);
}
if (lval > 9UL && lval < 256UL) {
outb(TWBR, (u_char) lval);
} else {
rc = -1;
}
break;
case TWI_GETSPEED:
lval = 2UL;
if (bit_is_set(TWSR, TWPS0)) {
lval *= 4UL;
}
if (bit_is_set(TWSR, TWPS1)) {
lval *= 16UL;
}
*((u_long *) conf) = NutGetCpuClock() / (16UL + lval * (u_long) inb(TWBR));
break;
case TWI_GETSTATUS:
break;
case TWI_SETSTATUS:
break;
default:
rc = -1;
break;
}
return rc;
#endif /* __AVR_ENHANCED__ */
}
/*
* Main application routine.
*/
int main(void)
{
uint32_t baud = 115200;
/*
* Register the UART device, open it, assign stdout to it and set
* the baudrate.
*/
NutRegisterDevice(&DEV_CONSOLE, 0, 0);
freopen(DEV_CONSOLE.dev_name, "w", stdout);
_ioctl(_fileno(stdout), UART_SETSPEED, &baud);
puts("\n\nNut/OS timer sample");
/*
* Display some general info.
*/
printf("CPU running at %lu Hz\n", NutGetCpuClock());
printf("%lu system ticks per second\n", NutTimerMillisToTicks(1000));
/*
* Run the demos.
*/
OneShotDemo(10);
PeriodicDemo(2);
DelayDemo();
SleepDemo(); /* Never returns. */
return 0;
}
/*!
* \brief Set transfer rate for a given device at SPI0.
*
* \param ix The device index, starting at 0.
* \param rate Transfer rate in bits per second.
*
*/
void Sppi0SetSpeed(u_char ix, u_long rate)
{
u_long fosc;
u_char i;
fosc = NutGetCpuClock();
sppi0_spcr[ix] &= ~(_BV(SPR1) | _BV(SPR0));
/* Find the frequency that is below or equal the requested
one, using the double speed bit if available. */
#if defined(SPI2X)
for (i = 0; i < 7; i++) {
fosc >>= 1;
if (fosc <= rate) {
break;
}
}
sppi0_spcr[ix] |= (i >> 1);
if (i < 6) {
sppi0_spsr[ix] = ~i & 1;
}
#else
for (i = 0; i < 3; i++) {
fosc >>= 2;
if (fosc <= rate) {
break;
}
}
sppi0_spcr[ix] |= i;
#endif
}
/*!
* \brief Handle I/O controls for debug device 0.
*
* The debug device doesn't support any.
*
* \return Always -1.
*/
static int DebugIOCtl(NUTDEVICE * dev, int req, void *conf)
{
if(req == UART_SETSPEED) {
#if defined(__AVR_ENHANCED__) && ((NUT_CPU_FREQ == 12000000) || (NUT_CPU_FREQ == 16000000))
/* On enhanced MCUs with 12.0 or 16.0 MHz we use double rate mode,
* so we can use 115200 bps with 12.0 MHz crystals
* and 57600 with 16.0 MHz crystals.
*/
sbi(UCSR0A, U2X0);
outb(UBRR, (uint8_t) ((((2UL * NutGetCpuClock()) / (*((uint32_t *)conf) * 8UL)) + 1UL) / 2UL) - 1UL);
#else
outb(UBRR, (uint8_t) ((((2UL * NutGetCpuClock()) / (*((uint32_t *)conf) * 16UL)) + 1UL) / 2UL) - 1UL);
#endif
return 0;
}
return -1;
}
