[U-Boot] [RFC][PATCH 12/21] [ns16550] Enable port-mapped access

Graeme Russ
2010-03-25T11:22:54Z

The x86 architecture exclusively uses Port-Mapped I/O (inb/outb) to access
the 16550 UARTs. This patch mimics how Linux selects between Memory-Mapped
and Port-Mapped I/O. This allows x86 boards to use CONFIG_SERIAL_MUTLI and
drop the custom serial port driver
---
drivers/serial/ns16550.c | 69 ++++++++++++++++++++++++++--------------------
1 files changed, 39 insertions(+), 30 deletions(-)

diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index b3bf10b..0e9beb7 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -7,6 +7,8 @@
#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 | \
@@ -14,28 +16,35 @@
#define UART_FCRVAL (UART_FCR_FIFO_EN | \
UART_FCR_RXSR | \
UART_FCR_TXSR) /* Clear & enable FIFOs */
+#ifdef CONFIG_X86
+#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)
{
- com_port->ier = 0x00;
+ serial_out(0x00, &com_port->ier);
#if defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)
- com_port->mdr1 = 0x7; /* mode select reset TL16C750*/
+ serial_out(0x7, &com_port->mdr1); /* 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;
+ 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)
- com_port->mdr1 = 3; /* /13 mode so Aptix 6MHz can hit 115200 */
+ serial_out(3, &com_port->mdr1); /* /13 mode so Aptix 6MHz can hit 115200 */
#else
- com_port->mdr1 = 0; /* /16 is proper to hit 115200 with 48MHz */
+ serial_out(0, &com_port->mdr1); /* /16 is proper to hit 115200 with 48MHz */
#endif
#endif /* CONFIG_OMAP */
}
@@ -43,42 +52,42 @@ void NS16550_init (NS16550_t com_port, int baud_divisor)
#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;
+ 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 ((com_port->lsr & UART_LSR_THRE) == 0);
- com_port->thr = c;
+ while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0);
+ serial_out(c, &com_port->thr);
}

#ifndef CONFIG_NS16550_MIN_FUNCTIONS
char NS16550_getc (NS16550_t com_port)
{
- while ((com_port->lsr & UART_LSR_DR) == 0) {
+ 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 (com_port->rbr);
+ return serial_in(&com_port->rbr);
}

int NS16550_tstc (NS16550_t com_port)
{
- return ((com_port->lsr & UART_LSR_DR) != 0);
+ return ((serial_in(&com_port->lsr) & UART_LSR_DR) != 0);
}

#endif /* CONFIG_NS16550_MIN_FUNCTIONS */
--
1.7.0.2.182.ge007