mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-17 01:04:19 +08:00
6e1af384f1
dt_xlate_reg() uses the ranges properties of a node's parentage to find the absolute physical address of the node's registers. The ns16550 driver uses this when no virtual-reg property is found. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
80 lines
1.9 KiB
C
80 lines
1.9 KiB
C
/*
|
|
* 16550 serial console support.
|
|
*
|
|
* Original copied from <file:arch/ppc/boot/common/ns16550.c>
|
|
* (which had no copyright)
|
|
* Modifications: 2006 (c) MontaVista Software, Inc.
|
|
*
|
|
* Modified by: Mark A. Greer <mgreer@mvista.com>
|
|
*/
|
|
#include <stdarg.h>
|
|
#include <stddef.h>
|
|
#include "types.h"
|
|
#include "string.h"
|
|
#include "stdio.h"
|
|
#include "io.h"
|
|
#include "ops.h"
|
|
|
|
#define UART_DLL 0 /* Out: Divisor Latch Low */
|
|
#define UART_DLM 1 /* Out: Divisor Latch High */
|
|
#define UART_FCR 2 /* Out: FIFO Control Register */
|
|
#define UART_LCR 3 /* Out: Line Control Register */
|
|
#define UART_MCR 4 /* Out: Modem Control Register */
|
|
#define UART_LSR 5 /* In: Line Status Register */
|
|
#define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
|
|
#define UART_LSR_DR 0x01 /* Receiver data ready */
|
|
#define UART_MSR 6 /* In: Modem Status Register */
|
|
#define UART_SCR 7 /* I/O: Scratch Register */
|
|
|
|
static unsigned char *reg_base;
|
|
static u32 reg_shift;
|
|
|
|
static int ns16550_open(void)
|
|
{
|
|
out_8(reg_base + (UART_FCR << reg_shift), 0x06);
|
|
return 0;
|
|
}
|
|
|
|
static void ns16550_putc(unsigned char c)
|
|
{
|
|
while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_THRE) == 0);
|
|
out_8(reg_base, c);
|
|
}
|
|
|
|
static unsigned char ns16550_getc(void)
|
|
{
|
|
while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) == 0);
|
|
return in_8(reg_base);
|
|
}
|
|
|
|
static u8 ns16550_tstc(void)
|
|
{
|
|
return ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) != 0);
|
|
}
|
|
|
|
int ns16550_console_init(void *devp, struct serial_console_data *scdp)
|
|
{
|
|
int n;
|
|
unsigned long reg_phys;
|
|
|
|
n = getprop(devp, "virtual-reg", ®_base, sizeof(reg_base));
|
|
if (n != sizeof(reg_base)) {
|
|
if (!dt_xlate_reg(devp, 0, ®_phys, NULL))
|
|
return -1;
|
|
|
|
reg_base = (void *)reg_phys;
|
|
}
|
|
|
|
n = getprop(devp, "reg-shift", ®_shift, sizeof(reg_shift));
|
|
if (n != sizeof(reg_shift))
|
|
reg_shift = 0;
|
|
|
|
scdp->open = ns16550_open;
|
|
scdp->putc = ns16550_putc;
|
|
scdp->getc = ns16550_getc;
|
|
scdp->tstc = ns16550_tstc;
|
|
scdp->close = NULL;
|
|
|
|
return 0;
|
|
}
|