ns16550.c
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/*
* COM1 NS16550 support
* originally from linux source (arch/ppc/boot/ns16550.c)
* modified to use CONFIG_SYS_ISA_MEM and new defines
*/
#include <config.h>
#include <ns16550.h>
#define UART_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */
#define UART_MCRVAL (UART_MCR_DTR | \
UART_MCR_RTS) /* RTS/DTR */
#define UART_FCRVAL (UART_FCR_FIFO_EN | \
UART_FCR_RXSR | \
UART_FCR_TXSR) /* Clear & enable FIFOs */
void NS16550_init (NS16550_t com_port, int baud_divisor)
{
com_port->ier = 0x00;
#ifdef CONFIG_OMAP
com_port->mdr1 = 0x7; /* mode select reset TL16C750*/
#endif
com_port->lcr = UART_LCR_BKSE | UART_LCRVAL;
com_port->dll = 0;
com_port->dlm = 0;
com_port->lcr = UART_LCRVAL;
com_port->mcr = UART_MCRVAL;
com_port->fcr = UART_FCRVAL;
com_port->lcr = UART_LCR_BKSE | UART_LCRVAL;
com_port->dll = baud_divisor & 0xff;
com_port->dlm = (baud_divisor >> 8) & 0xff;
com_port->lcr = UART_LCRVAL;
#if defined(CONFIG_OMAP)
#if defined(CONFIG_APTIX)
com_port->mdr1 = 3; /* /13 mode so Aptix 6MHz can hit 115200 */
#else
com_port->mdr1 = 0; /* /16 is proper to hit 115200 with 48MHz */
#endif
#endif /* CONFIG_OMAP */
}
#ifndef CONFIG_NS16550_MIN_FUNCTIONS
void NS16550_reinit (NS16550_t com_port, int baud_divisor)
{
com_port->ier = 0x00;
com_port->lcr = UART_LCR_BKSE | UART_LCRVAL;
com_port->dll = 0;
com_port->dlm = 0;
com_port->lcr = UART_LCRVAL;
com_port->mcr = UART_MCRVAL;
com_port->fcr = UART_FCRVAL;
com_port->lcr = UART_LCR_BKSE;
com_port->dll = baud_divisor & 0xff;
com_port->dlm = (baud_divisor >> 8) & 0xff;
com_port->lcr = UART_LCRVAL;
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */
void NS16550_putc (NS16550_t com_port, char c)
{
while ((com_port->lsr & UART_LSR_THRE) == 0);
com_port->thr = c;
}
#ifndef CONFIG_NS16550_MIN_FUNCTIONS
char NS16550_getc (NS16550_t com_port)
{
while ((com_port->lsr & UART_LSR_DR) == 0) {
#ifdef CONFIG_USB_TTY
extern void usbtty_poll(void);
usbtty_poll();
#endif
}
return (com_port->rbr);
}
int NS16550_tstc (NS16550_t com_port)
{
return ((com_port->lsr & UART_LSR_DR) != 0);
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */