blob: 8c9ead94be06f70b891a6bd90b39f98a0d4bbbd4 [file] [log] [blame]
Mark A. Greer0c176fa2006-10-16 13:52:09 -07001/*
2 * 16550 serial console support.
3 *
4 * Original copied from <file:arch/ppc/boot/common/ns16550.c>
5 * (which had no copyright)
6 * Modifications: 2006 (c) MontaVista Software, Inc.
7 *
8 * Modified by: Mark A. Greer <mgreer@mvista.com>
9 */
10#include <stdarg.h>
11#include <stddef.h>
12#include "types.h"
13#include "string.h"
14#include "stdio.h"
15#include "io.h"
16#include "ops.h"
17
18#define UART_DLL 0 /* Out: Divisor Latch Low */
19#define UART_DLM 1 /* Out: Divisor Latch High */
20#define UART_FCR 2 /* Out: FIFO Control Register */
21#define UART_LCR 3 /* Out: Line Control Register */
22#define UART_MCR 4 /* Out: Modem Control Register */
23#define UART_LSR 5 /* In: Line Status Register */
24#define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
25#define UART_LSR_DR 0x01 /* Receiver data ready */
26#define UART_MSR 6 /* In: Modem Status Register */
27#define UART_SCR 7 /* I/O: Scratch Register */
28
29static unsigned char *reg_base;
30static u32 reg_shift;
31
32static int ns16550_open(void)
33{
34 out_8(reg_base + (UART_FCR << reg_shift), 0x06);
35 return 0;
36}
37
38static void ns16550_putc(unsigned char c)
39{
40 while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_THRE) == 0);
41 out_8(reg_base, c);
42}
43
44static unsigned char ns16550_getc(void)
45{
46 while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) == 0);
47 return in_8(reg_base);
48}
49
50static u8 ns16550_tstc(void)
51{
52 return ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) != 0);
53}
54
55int ns16550_console_init(void *devp, struct serial_console_data *scdp)
56{
57 int n;
John Linn2f0b45f2008-04-03 03:52:14 +110058 u32 reg_offset;
Mark A. Greer0c176fa2006-10-16 13:52:09 -070059
Laurent Pinchartda0a5f02008-04-10 17:03:04 +020060 if (dt_get_virtual_reg(devp, (void **)&reg_base, 1) < 1)
61 return -1;
Mark A. Greer0c176fa2006-10-16 13:52:09 -070062
John Linn2f0b45f2008-04-03 03:52:14 +110063 n = getprop(devp, "reg-offset", &reg_offset, sizeof(reg_offset));
64 if (n == sizeof(reg_offset))
65 reg_base += reg_offset;
66
Mark A. Greer0c176fa2006-10-16 13:52:09 -070067 n = getprop(devp, "reg-shift", &reg_shift, sizeof(reg_shift));
68 if (n != sizeof(reg_shift))
69 reg_shift = 0;
70
71 scdp->open = ns16550_open;
72 scdp->putc = ns16550_putc;
73 scdp->getc = ns16550_getc;
74 scdp->tstc = ns16550_tstc;
75 scdp->close = NULL;
76
77 return 0;
78}