int gps_autonegotiate_baud(gps_t *g, int guessbaud)
{
int bauds[] = { 4800, 9600, 19200, 38400, 600, 1200, 2400, -1 };
int baudidx = -1;
uint8_t rpy[GPS_MESSAGE_MAXLEN + 1];
rpy[GPS_MESSAGE_MAXLEN] = 0;
while (1) {
int baud;
if (baudidx < 0)
baud = guessbaud;
else {
if (bauds[baudidx] < 0)
baudidx = 0;
baud = bauds[baudidx];
}
printf("Trying %6d baud...", baud);
fflush(NULL);
// enable all output sentences
gps_write_command(g, "$PGRMO,,3*");
serial_setbaud(g->fd, baud);
read_flush(g->fd);
for (int i = 0; i < 4; i++) {
int res = gps_readline(g, rpy, GPS_MESSAGE_MAXLEN);
if (!res) {
printf("GPS found!\n");
return 0;
}
printf(".");
fflush(NULL);
}
printf("\n");
baudidx++;
}
// no luck
return -1;
}
/* initialize the serial ports */
int
serial_init(struct Device_Conf *dev){
int i = dev->unit;
USART_TypeDef *addr;
int irq;
int b;
int altpins = dev->flags & CFFLAGS_ALTPINS;
finit( & com[i].file );
com[i].file.fs = &serial_port_fs;
com[i].file.codepage = CODEPAGE_UTF8;
com[i].head = com[i].tail = com[i].len = 0;
com[i].status = 0;
com[i].portno = i;
com[i].file.d = (void*)&com[i];
// enable gpio clock, usart clock, configure pins
serial_pins_init( i, altpins );
switch(i){
case 0:
addr = USART1;
com[i].baudclock = apb2_clock_freq();
irq = (int) IRQ_USART1;
break;
case 1:
addr = USART2;
com[i].baudclock = apb1_clock_freq();
irq = (int) IRQ_USART2;
break;
case 2:
addr = USART3;
com[i].baudclock = apb1_clock_freq();
irq = (int) IRQ_USART3_4;
break;
default:
PANIC("invalid serial");
break;
}
com[i].addr = addr;
if( dev->baud )
serial_setbaud(i, b=dev->baud);
else
serial_setbaud(i, b=9600);
addr->CR1 = 0x0C // enable rx/tx, no parity, 8 bit, ...
| 0x20 // enable RX irq
| 1; // enable
// enable ints
nvic_enable( irq, IPL_TTY );
if( !serial0_port ){
serial0_port = &com[i].file;
}
bootmsg("%s at io 0x%x irq %d %d baud\n", dev->name, addr, irq, b);
return (int) &com[i].file;
}
