u-boot/drivers/serial/ns16550.c
Stefan Roese 1a2d9b30e3 ns16550: Add WATCHDOG_RESET to putc for short watchdog timeout boards
Call watchdog_reset() upon newline. This is done here in putc
since the environment code uses a single puts() to print the complete
envrironment upon "printenv". So we can't put this watchdog call
in puts().

This is needed for boards with a very short watchdog timeout, like the
lwmon5 with a 100ms timeout. Without this patch this board resets in the
commands with long outputs, like "printenv" or "fdt print".

Note that the image size is not increased with this patch when
CONFIG_HW_WATCHDOG or CONFIG_WATCHDOG are not defined since the compiler
optimizes this additional code away.

Signed-off-by: Stefan Roese <sr@denx.de>

Fix typo in comment.
Signed-off-by: Wolfgang Denk <wd@denx.de>
2010-10-13 21:59:31 +02:00

102 lines
3.1 KiB
C

/*
* COM1 NS16550 support
* originally from linux source (arch/powerpc/boot/ns16550.c)
* modified to use CONFIG_SYS_ISA_MEM and new defines
*/
#include <config.h>
#include <ns16550.h>
#include <watchdog.h>
#include <linux/types.h>
#include <asm/io.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 */
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
#define serial_out(x,y) outb(x,(ulong)y)
#define serial_in(y) inb((ulong)y)
#else
#define serial_out(x,y) writeb(x,y)
#define serial_in(y) readb(y)
#endif
void NS16550_init (NS16550_t com_port, int baud_divisor)
{
serial_out(0x00, &com_port->ier);
#if defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)
serial_out(0x7, &com_port->mdr1); /* mode select reset TL16C750*/
#endif
serial_out(UART_LCR_BKSE | UART_LCRVAL, (ulong)&com_port->lcr);
serial_out(0, &com_port->dll);
serial_out(0, &com_port->dlm);
serial_out(UART_LCRVAL, &com_port->lcr);
serial_out(UART_MCRVAL, &com_port->mcr);
serial_out(UART_FCRVAL, &com_port->fcr);
serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
serial_out(baud_divisor & 0xff, &com_port->dll);
serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
serial_out(UART_LCRVAL, &com_port->lcr);
#if defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)
#if defined(CONFIG_APTIX)
serial_out(3, &com_port->mdr1); /* /13 mode so Aptix 6MHz can hit 115200 */
#else
serial_out(0, &com_port->mdr1); /* /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)
{
serial_out(0x00, &com_port->ier);
serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
serial_out(0, &com_port->dll);
serial_out(0, &com_port->dlm);
serial_out(UART_LCRVAL, &com_port->lcr);
serial_out(UART_MCRVAL, &com_port->mcr);
serial_out(UART_FCRVAL, &com_port->fcr);
serial_out(UART_LCR_BKSE, &com_port->lcr);
serial_out(baud_divisor & 0xff, &com_port->dll);
serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
serial_out(UART_LCRVAL, &com_port->lcr);
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */
void NS16550_putc (NS16550_t com_port, char c)
{
while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0);
serial_out(c, &com_port->thr);
/*
* Call watchdog_reset() upon newline. This is done here in putc
* since the environment code uses a single puts() to print the complete
* environment upon "printenv". So we can't put this watchdog call
* in puts().
*/
if (c == '\n')
WATCHDOG_RESET();
}
#ifndef CONFIG_NS16550_MIN_FUNCTIONS
char NS16550_getc (NS16550_t com_port)
{
while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
#ifdef CONFIG_USB_TTY
extern void usbtty_poll(void);
usbtty_poll();
#endif
WATCHDOG_RESET();
}
return serial_in(&com_port->rbr);
}
int NS16550_tstc (NS16550_t com_port)
{
return ((serial_in(&com_port->lsr) & UART_LSR_DR) != 0);
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */