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#include "project.h"
#define RXR ((0))
#define TXR ((0))
#define DLLR ((0))
#define IER ((1))
#define DLHR ((1))
#define IIR ((2))
#define FCR ((2))
#define LCR ((3))
#define LCR_WS0 (1<<0)
#define LCR_WS1 (1<<1)
#define LCR_NSTOP (1<<2)
#define LCR_PARITY_ENABLE (1<<3)
#define LCR_EVEN_PARITY (1<<4)
#define LCR_STUCK_PARITY (1<<5)
#define LCR_BREAK (1<<6)
#define LCR_DLAB (1<<7)
#define MCR ((4))
#define MCR_DTR (1<<0)
#define MCR_RTS (1<<1)
#define MCR_AUX1 (1<<2)
#define MCR_AUX2 (1<<3)
#define MCR_LOOP (1<<4)
#define MCR_AUTOFLOW (1<<5)
#define LSR ((5))
#define LSR_DA (1<<0)
#define LSR_OR (1<<1)
#define LSR_PE (1<<2)
#define LSR_FE (1<<3)
#define LSR_BRK (1<<4)
#define LSR_THRE (1<<5)
#define LSR_THREI (1<<6)
#define LSR_FIFOE (1<<7)
#define MSR ((6))
#define MSR_DCTS (1<<0)
#define MSR_DDSR (1<<1)
#define MSR_TERI (1<<2)
#define MSR_DDCD (1<<3)
#define MSR_CTS (1<<4)
#define MSR_DSR (1<<5)
#define MSR_RI (1<<6)
#define MSR_DCD (1<<7)
#define SR ((7))
/* 0 */
static uint8_t dllr = 1; /* 115200 baud */
/* 1 */
static uint8_t dlhr = 0;
static uint8_t ier = 0;
/* 2 */
static uint8_t iir = 0;
/* 3 */
static uint8_t lcr = LCR_WS0 | LCR_WS1; /* 8 bits, 1 stop, no parity */
/* 4 */
static uint8_t mcr = MCR_RTS | MCR_DTR; /* RTS and DTR on */
/* 5 */
static uint8_t lsr = LSR_THRE | LSR_THREI;
/* 6 */
static uint8_t msr = MSR_CTS | MSR_DSR | MSR_DCD;
/* 7 */
static uint8_t sr = 0;
static void vuart_xmit (uint8_t c)
{
led1 = 100;
ring_write_byte (&usart_tx_ring, c);
usart_kick();
ring_write_byte (&cdcacm_tx_ring, c);
}
static int vuart_recv_empty (void)
{
if (!ring_empty (&usart_rx_ring))
return 0;
if (!ring_empty (&cdcacm_rx_ring))
return 0;
return 1;
}
static int vuart_recv (uint8_t *c)
{
*c = 0;
if (!ring_read_byte (&usart_rx_ring, c)) {
led2 = 100;
return 0;
}
if (!ring_read_byte (&cdcacm_rx_ring, c)) {
led2 = 100;
return 0;
}
return -1;
}
static void update_lsr (void)
{
if (vuart_recv_empty())
lsr &= ~LSR_DA;
else
lsr |= LSR_DA;
}
uint8_t vuart_read (unsigned reg)
{
uint8_t val;
switch (reg) {
case RXR:
//case DLLR:
if (! (lcr & LCR_DLAB)) {
vuart_recv (&val);
update_lsr();
return val;
} else
return dllr;
case IER:
//case DLLH:
return (lcr & LCR_DLAB) ? dlhr : ier;
case IIR:
return iir;
case LCR:
return lcr;
case MCR:
return mcr;
case LSR:
update_lsr();
val = lsr;
lsr &= 0xe1;
return val;
case MSR:
val = msr;
msr &= 0xf0;
return val;
case SR:
return sr;
}
return 0;
}
void vuart_write (unsigned reg, uint8_t val)
{
switch (reg) {
case RXR:
//case DLLR:
if (! (lcr & LCR_DLAB))
vuart_xmit (val);
else
dllr = val;
break;
case IER:
//case DLHR:
if (! (lcr & LCR_DLAB))
ier = val & 0xf;
else
dlhr = val;
break;
case LCR:
lcr = val;
break;
case MCR:
mcr = val & 0x1f;
break;
case SR:
sr = val;
break;
}
}
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