u-boot/drivers/serial/ns16550.c
Manfred Huber fd2aeac560 omap3_beagle: Flush UART3 xmit on enable if TEMT is broken
Flush UART3 xmit on enable if TEMT is broken

On some OMAP3 devices when UART3 is configured for boot mode before SPL starts
only THRE bit is set. We have to empty the transmitter before initialization
starts. This patch avoids the use of CONFIG_SYS_NS16550_BROKEN_TEMT.

Signed-off-by: Manfred Huber <man.huber@arcor.de>
Tested-by: Javier Martinez Canillas <javier@dowhile0.org>
Tested-by: Andreas Bießmann <andreas.devel@googlemail.com>
2013-04-08 11:29:05 -04:00

138 lines
4.3 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)
#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
#define serial_out(x, y) out_be32(y, x)
#define serial_in(y) in_be32(y)
#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
#define serial_out(x, y) out_le32(y, x)
#define serial_in(y) in_le32(y)
#else
#define serial_out(x, y) writeb(x, y)
#define serial_in(y) readb(y)
#endif
#ifndef CONFIG_SYS_NS16550_IER
#define CONFIG_SYS_NS16550_IER 0x00
#endif /* CONFIG_SYS_NS16550_IER */
void NS16550_init(NS16550_t com_port, int baud_divisor)
{
#if (defined(CONFIG_SPL_BUILD) && defined(CONFIG_OMAP34XX))
/*
* On some OMAP3 devices when UART3 is configured for boot mode before
* SPL starts only THRE bit is set. We have to empty the transmitter
* before initialization starts.
*/
if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
== UART_LSR_THRE) {
serial_out(UART_LCR_DLAB, &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);
serial_out(0, &com_port->mdr1);
}
#endif
while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
;
serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
#if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \
defined(CONFIG_AM33XX) || defined(CONFIG_TI814X)
serial_out(0x7, &com_port->mdr1); /* mode select reset TL16C750*/
#endif
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 | 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)) || \
defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
defined(CONFIG_TI814X)
#if defined(CONFIG_APTIX)
/* /13 mode so Aptix 6MHz can hit 115200 */
serial_out(3, &com_port->mdr1);
#else
/* /16 is proper to hit 115200 with 48MHz */
serial_out(0, &com_port->mdr1);
#endif
#endif /* CONFIG_OMAP */
}
#ifndef CONFIG_NS16550_MIN_FUNCTIONS
void NS16550_reinit(NS16550_t com_port, int baud_divisor)
{
serial_out(CONFIG_SYS_NS16550_IER, &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) {
#if !defined(CONFIG_SPL_BUILD) && defined(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 */