1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Generic serial console support
4 *
5 * Author: Mark A. Greer <mgreer@mvista.com>
6 *
7 * Code in serial_edit_cmdline() copied from <file:arch/ppc/boot/simple/misc.c>
8 * and was written by Matt Porter <mporter@kernel.crashing.org>.
9 *
10 * 2001,2006 (c) MontaVista Software, Inc.
11 */
12#include <stdarg.h>
13#include <stddef.h>
14#include "types.h"
15#include "string.h"
16#include "stdio.h"
17#include "io.h"
18#include "ops.h"
19
20static int serial_open(void)
21{
22	struct serial_console_data *scdp = console_ops.data;
23	return scdp->open();
24}
25
26static void serial_write(const char *buf, int len)
27{
28	struct serial_console_data *scdp = console_ops.data;
29
30	while (*buf != '\0')
31		scdp->putc(*buf++);
32}
33
34static void serial_edit_cmdline(char *buf, int len, unsigned int timeout)
35{
36	int timer = 0, count;
37	char ch, *cp;
38	struct serial_console_data *scdp = console_ops.data;
39
40	cp = buf;
41	count = strlen(buf);
42	cp = &buf[count];
43	count++;
44
45	do {
46		if (scdp->tstc()) {
47			while (((ch = scdp->getc()) != '\n') && (ch != '\r')) {
48				/* Test for backspace/delete */
49				if ((ch == '\b') || (ch == '\177')) {
50					if (cp != buf) {
51						cp--;
52						count--;
53						printf("\b \b");
54					}
55				/* Test for ^x/^u (and wipe the line) */
56				} else if ((ch == '\030') || (ch == '\025')) {
57					while (cp != buf) {
58						cp--;
59						count--;
60						printf("\b \b");
61					}
62				} else if (count < len) {
63						*cp++ = ch;
64						count++;
65						scdp->putc(ch);
66				}
67			}
68			break;  /* Exit 'timer' loop */
69		}
70		udelay(1000);  /* 1 msec */
71	} while (timer++ < timeout);
72	*cp = 0;
73}
74
75static void serial_close(void)
76{
77	struct serial_console_data *scdp = console_ops.data;
78
79	if (scdp->close)
80		scdp->close();
81}
82
83static void *serial_get_stdout_devp(void)
84{
85	void *devp;
86	char devtype[MAX_PROP_LEN];
87	char path[MAX_PATH_LEN];
88
89	devp = finddevice("/chosen");
90	if (devp == NULL)
91		goto err_out;
92
93	if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0 ||
94		getprop(devp, "stdout-path", path, MAX_PATH_LEN) > 0) {
95		devp = finddevice(path);
96		if (devp == NULL)
97			goto err_out;
98
99		if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
100				&& !strcmp(devtype, "serial"))
101			return devp;
102	}
103err_out:
104	return NULL;
105}
106
107static struct serial_console_data serial_cd;
108
109/* Node's "compatible" property determines which serial driver to use */
110int serial_console_init(void)
111{
112	void *devp;
113	int rc = -1;
114
115	devp = serial_get_stdout_devp();
116	if (devp == NULL)
117		goto err_out;
118
119	if (dt_is_compatible(devp, "ns16550") ||
120	    dt_is_compatible(devp, "pnpPNP,501"))
121		rc = ns16550_console_init(devp, &serial_cd);
122#ifdef CONFIG_CPM
123	else if (dt_is_compatible(devp, "fsl,cpm1-scc-uart") ||
124	         dt_is_compatible(devp, "fsl,cpm1-smc-uart") ||
125	         dt_is_compatible(devp, "fsl,cpm2-scc-uart") ||
126	         dt_is_compatible(devp, "fsl,cpm2-smc-uart"))
127		rc = cpm_console_init(devp, &serial_cd);
128#endif
129#ifdef CONFIG_PPC_MPC52xx
130	else if (dt_is_compatible(devp, "fsl,mpc5200-psc-uart"))
131		rc = mpc5200_psc_console_init(devp, &serial_cd);
132#endif
133#ifdef CONFIG_PPC_POWERNV
134	else if (dt_is_compatible(devp, "ibm,opal-console-raw"))
135		rc = opal_console_init(devp, &serial_cd);
136#endif
137
138	/* Add other serial console driver calls here */
139
140	if (!rc) {
141		console_ops.open = serial_open;
142		console_ops.write = serial_write;
143		console_ops.close = serial_close;
144		console_ops.data = &serial_cd;
145
146		if (serial_cd.getc)
147			console_ops.edit_cmdline = serial_edit_cmdline;
148
149		return 0;
150	}
151err_out:
152	return -1;
153}
154