1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * 16550 serial console support.
 4 *
 5 * Original copied from <file:arch/ppc/boot/common/ns16550.c>
 6 * (which had no copyright)
 7 * Modifications: 2006 (c) MontaVista Software, Inc.
 8 *
 9 * Modified by: Mark A. Greer <mgreer@mvista.com>
10 */
11#include <stdarg.h>
12#include <stddef.h>
13#include "types.h"
14#include "string.h"
15#include "stdio.h"
16#include "io.h"
17#include "ops.h"
18
19#define UART_DLL	0	/* Out: Divisor Latch Low */
20#define UART_DLM	1	/* Out: Divisor Latch High */
21#define UART_FCR	2	/* Out: FIFO Control Register */
22#define UART_LCR	3	/* Out: Line Control Register */
23#define UART_MCR	4	/* Out: Modem Control Register */
24#define UART_LSR	5	/* In:  Line Status Register */
25#define UART_LSR_THRE	0x20	/* Transmit-hold-register empty */
26#define UART_LSR_DR	0x01	/* Receiver data ready */
27#define UART_MSR	6	/* In:  Modem Status Register */
28#define UART_SCR	7	/* I/O: Scratch Register */
29
30static unsigned char *reg_base;
31static u32 reg_shift;
32
33static int ns16550_open(void)
34{
35	out_8(reg_base + (UART_FCR << reg_shift), 0x06);
36	return 0;
37}
38
39static void ns16550_putc(unsigned char c)
40{
41	while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_THRE) == 0);
42	out_8(reg_base, c);
43}
44
45static unsigned char ns16550_getc(void)
46{
47	while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) == 0);
48	return in_8(reg_base);
49}
50
51static u8 ns16550_tstc(void)
52{
53	return ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) != 0);
54}
55
56int ns16550_console_init(void *devp, struct serial_console_data *scdp)
57{
58	int n;
59	u32 reg_offset;
60
61	if (dt_get_virtual_reg(devp, (void **)&reg_base, 1) < 1)
62		return -1;
63
64	n = getprop(devp, "reg-offset", &reg_offset, sizeof(reg_offset));
65	if (n == sizeof(reg_offset))
66		reg_base += reg_offset;
67
68	n = getprop(devp, "reg-shift", &reg_shift, sizeof(reg_shift));
69	if (n != sizeof(reg_shift))
70		reg_shift = 0;
71
72	scdp->open = ns16550_open;
73	scdp->putc = ns16550_putc;
74	scdp->getc = ns16550_getc;
75	scdp->tstc = ns16550_tstc;
76	scdp->close = NULL;
77
78	return 0;
79}

 
 1/*
 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;
58	u32 reg_offset;
59
60	if (dt_get_virtual_reg(devp, (void **)&reg_base, 1) < 1)
61		return -1;
62
63	n = getprop(devp, "reg-offset", &reg_offset, sizeof(reg_offset));
64	if (n == sizeof(reg_offset))
65		reg_base += reg_offset;
66
67	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}