serial.c

Intel PXA270的bootloader程序,在linux环境下运行的.

#include <hardware.h>
#include <stdarg.h>
#include <io.h>
#include <serial.h>

#if defined(USE_FFUART)
static const unsigned long base = 0x40100000;
#elif defined(USE_BTUART)
static const unsigned long base = 0x40200000;
#elif defined(USE_STUART)
static const unsigned long base = 0x40700000;
#endif

#define uart_put(v, p)		writeb(v, base + (p))
#define uart_get(p)			readb(base + (p))

extern bool uart_init(void){
	int i;

	if (uart_get(UART_IER) & IER_UUE)
		while (!(uart_get(UART_LSR) & LSR_TEMT));
#if defined(USE_FFUART)
	pxa_gpio_mode(GPIO34_FFRXD_MD);
	pxa_gpio_mode(GPIO39_FFTXD_MD);
#elif defined(USE_BTUART)
	pxa_gpio_mode(GPIO42_BTRXD_MD);
	pxa_gpio_mode(GPIO43_BTTXD_MD);
#elif defined(USE_STUART)
	pxa_gpio_mode(GPIO46_STRXD_MD);
	pxa_gpio_mode(GPIO47_STTXD_MD);
#endif

	uart_put(~IER_UUE, UART_IER);
	uart_put(0x03, UART_LCR);		// 8bit data, 1 stop bit, no parity
	uart_put(0x07, UART_FCR);
	uart_put(0x03 | LCR_DLAB, UART_LCR);
	uart_put(BaudToDLV(UART_BAUDRATE) >> 8, UART_DLH);
	uart_put(BaudToDLV(UART_BAUDRATE) & 0xFF, UART_DLL);
	uart_put(0x03, UART_LCR);
	uart_put(IER_UUE, UART_IER);	// uart enable

	i=20; do {
		uart_put('\r', UART_THR);
	} while (--i);
	return true;
}

extern int uart_putc(int ch){
	if (ch == '\n') uart_putc('\r');
	while (!(uart_get(UART_LSR) & LSR_TDRQ));
	uart_put(ch, UART_THR);
	return ch;
}

extern int uart_getc(void){
	int ch = -1;
	if (uart_get(UART_LSR) & LSR_DR)
		ch = uart_get(UART_RBR);
	if (ch == '\r') ch = '\n';
	return ch;
}

extern int uart_puts(const char *s){
	const char *t = s;
	while (*t) uart_putc(*t++);
	return t - s;
}

extern int uart_putb(int ch){
	while (!(uart_get(UART_LSR) & LSR_TDRQ));
	uart_put(ch, UART_THR);
	return ch;
}

extern int uart_getb(void){
	int ch = -1;
	if (uart_get(UART_LSR) & LSR_DR)
		ch = uart_get(UART_RBR);
	return ch;
}


extern int uart_write(const void *buff, int count){
	const char *s = buff;
	while (count-- > 0){
		while (!(uart_get(UART_LSR) & LSR_TDRQ));
		uart_put(*s++, UART_THR);
	}
	return count;
}