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#include "uart.h" #include "types.h" #include "interrupt.h" #include "event.h" #include "led.h" #include "panic.h" #define UARTBASE 0xE000C000 #define RBR 0x00 #define THR 0x00 #define DLL 0x00 #define DLM 0x04 #define IER 0x04 #define IIR 0x08 #define FCR 0x08 #define LCR 0x0c #define LSR 0x14 #define SCR 0x1c #define ACR 0x20 #define FDR 0x28 #define TER 0x30 #define UREG(x) (((volatile unsigned char *)UARTBASE)[x]) #define U0THRE ((UREG(LSR) & (1<<5))) /* UART0 transmitter holding register is empty */ #define U0DR ((UREG(LSR) & (1<<0))) /* UART0 data ready */ #define UART_TXBUFSIZE 128 #define UART_RXBUFSIZE 128 char uart_txbuf[UART_TXBUFSIZE]; char uart_rxbuf[UART_RXBUFSIZE]; volatile unsigned int uart_txread; volatile unsigned int uart_txwrite; volatile unsigned int uart_rxread; volatile unsigned int uart_rxwrite; volatile bool tx_running; void __attribute__((interrupt("IRQ"))) uart_interrupt_handler(void); #ifdef USE_UART void init_uart(void) { UREG(FDR) = 0x10; /* DivAddVal = 0, MulVal = 1 */ UREG(LCR) = 0x80; UREG(DLM) = 0x00; UREG(DLL) = 0x20; /* 58982400 / (16*115200) */ UREG(LCR) = 0x13; UREG(FCR) = 0x07; uart_txread = 0; uart_txwrite = 0; uart_rxread = 0; uart_rxwrite = 0; tx_running = FALSE; interrupt_register(UART0, uart_interrupt_handler); UREG(IER) = 0x03; /* RBR and THRE interrupt enable */ } void putch(char c) { CHECKPOINT(4); /* Wait for space in the buffer */ while (uart_txread == ((uart_txwrite+1) % UART_TXBUFSIZE)) ; interrupt_block(); if (uart_txread == uart_txwrite) { if (U0THRE) { tx_running = TRUE; UREG(THR) = c; interrupt_unblock(); CHECKPOINT(5); return; } } uart_txbuf[uart_txwrite] = c; uart_txwrite = (uart_txwrite + 1) % UART_TXBUFSIZE; if (!tx_running) { if (uart_txread != uart_txwrite) { tx_running = TRUE; uart_txread = (uart_txread + 1) % UART_TXBUFSIZE; UREG(THR) = c; } } interrupt_unblock(); CHECKPOINT(5); } void putch_irq(char c) { /* Hope for space in the buffer */ // if (uart_txread == ((uart_txwrite+1) % UART_TXBUFSIZE)) // return; #if 1 if (uart_txread == uart_txwrite) { if (U0THRE) { tx_running = TRUE; UREG(THR) = c; return; } } uart_txbuf[uart_txwrite] = c; uart_txwrite = (uart_txwrite + 1) % UART_TXBUFSIZE; if (!tx_running) { if (uart_txread != uart_txwrite) { tx_running = TRUE; uart_txread = (uart_txread + 1) % UART_TXBUFSIZE; UREG(THR) = c; } } #else UREG(THR) = c; #endif } void __attribute__((interrupt("IRQ"))) uart_interrupt_handler(void) { bool active = FALSE; int source; int i; /* uart_txread and uart_txwrite are volatile. We don't need * to treat them as such in this handler, so let the compiler * have an easier time. */ unsigned int local_txwrite; unsigned int local_txread; unsigned int local_rxwrite; unsigned int local_rxread; CHECKPOINT(((checkpoint & 0x00ff) | 0x0100)); source = UREG(IIR); switch (source & 0x0e) { case 0x4: /* Receive Data Available */ case 0xc: /* Character Time-out Indicator */ local_rxwrite = uart_rxwrite; local_rxread = uart_rxread; while (U0DR) { unsigned char c = UREG(RBR); if (local_rxread != ((local_rxwrite+1) % UART_RXBUFSIZE)) { uart_rxbuf[local_rxwrite] = c; local_rxwrite = (local_rxwrite + 1) % UART_RXBUFSIZE; } } uart_rxwrite = local_rxwrite; event_set(EVENT_UART_INPUT); break; case 0x2: /* THRE interrupt */ local_txwrite = uart_txwrite; local_txread = uart_txread; for (i = 0; (i < 16) && (local_txwrite != local_txread); i++) { UREG(THR) = uart_txbuf[local_txread]; local_txread = (local_txread + 1) % UART_TXBUFSIZE; active = TRUE; } uart_txread = local_txread; if (!active) tx_running = FALSE; break; case 0x6: /* Receive Line Status */ default: /* Anything else */ break; } CHECKPOINT((checkpoint & 0x00ff) | 0x0200); interrupt_clear(); } void putstr(char *s) { while (*s) putch(*s++); } void putint(unsigned int n) { char s[11]; int i; i = 10; s[i] = '\0'; do { s[--i] = n % 10 + '0'; } while ((n /= 10) > 0); putstr(s+i); } void putint_s(int n) { char s[12]; int i; int neg; /* OK, technically, this might not work properly for the most * negative possible number. Oh well. */ neg = (n < 0); if (neg) n = -n; i = 11; s[i] = '\0'; do { s[--i] = n % 10 + '0'; } while ((n /= 10) > 0); if (neg) s[--i] = '-'; putstr(s+i); } void puthex(unsigned int n) { char s[9]; int i; i = 8; s[i] = '\0'; do { int x = n % 16; if (x > 9) x += 'A' - '0' - 10; s[--i] = x + '0'; } while ((n /= 16) > 0); putstr(s+i); } bool getch(char *c) { if (uart_rxread == uart_rxwrite) return FALSE; *c = uart_rxbuf[uart_rxread]; uart_rxread = (uart_rxread + 1) % UART_RXBUFSIZE; return TRUE; } #endif