xref: /openbmc/linux/arch/powerpc/boot/serial.c (revision c21b37f6)
1 /*
2  * Generic serial console support
3  *
4  * Author: Mark A. Greer <mgreer@mvista.com>
5  *
6  * Code in serial_edit_cmdline() copied from <file:arch/ppc/boot/simple/misc.c>
7  * and was written by Matt Porter <mporter@kernel.crashing.org>.
8  *
9  * 2001,2006 (c) MontaVista Software, Inc.  This file is licensed under
10  * the terms of the GNU General Public License version 2.  This program
11  * is licensed "as is" without any warranty of any kind, whether express
12  * or implied.
13  */
14 #include <stdarg.h>
15 #include <stddef.h>
16 #include "types.h"
17 #include "string.h"
18 #include "stdio.h"
19 #include "io.h"
20 #include "ops.h"
21 
22 extern void udelay(long delay);
23 
24 static int serial_open(void)
25 {
26 	struct serial_console_data *scdp = console_ops.data;
27 	return scdp->open();
28 }
29 
30 static void serial_write(const char *buf, int len)
31 {
32 	struct serial_console_data *scdp = console_ops.data;
33 
34 	while (*buf != '\0')
35 		scdp->putc(*buf++);
36 }
37 
38 static void serial_edit_cmdline(char *buf, int len)
39 {
40 	int timer = 0, count;
41 	char ch, *cp;
42 	struct serial_console_data *scdp = console_ops.data;
43 
44 	cp = buf;
45 	count = strlen(buf);
46 	cp = &buf[count];
47 	count++;
48 
49 	while (timer++ < 5*1000) {
50 		if (scdp->tstc()) {
51 			while (((ch = scdp->getc()) != '\n') && (ch != '\r')) {
52 				/* Test for backspace/delete */
53 				if ((ch == '\b') || (ch == '\177')) {
54 					if (cp != buf) {
55 						cp--;
56 						count--;
57 						printf("\b \b");
58 					}
59 				/* Test for ^x/^u (and wipe the line) */
60 				} else if ((ch == '\030') || (ch == '\025')) {
61 					while (cp != buf) {
62 						cp--;
63 						count--;
64 						printf("\b \b");
65 					}
66 				} else if (count < len) {
67 						*cp++ = ch;
68 						count++;
69 						scdp->putc(ch);
70 				}
71 			}
72 			break;  /* Exit 'timer' loop */
73 		}
74 		udelay(1000);  /* 1 msec */
75 	}
76 	*cp = 0;
77 }
78 
79 static void serial_close(void)
80 {
81 	struct serial_console_data *scdp = console_ops.data;
82 
83 	if (scdp->close)
84 		scdp->close();
85 }
86 
87 static void *serial_get_stdout_devp(void)
88 {
89 	void *devp;
90 	char devtype[MAX_PROP_LEN];
91 	char path[MAX_PATH_LEN];
92 
93 	devp = finddevice("/chosen");
94 	if (devp == NULL)
95 		goto err_out;
96 
97 	if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0) {
98 		devp = finddevice(path);
99 		if (devp == NULL)
100 			goto err_out;
101 
102 		if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
103 				&& !strcmp(devtype, "serial"))
104 			return devp;
105 	}
106 err_out:
107 	return NULL;
108 }
109 
110 static struct serial_console_data serial_cd;
111 
112 /* Node's "compatible" property determines which serial driver to use */
113 int serial_console_init(void)
114 {
115 	void *devp;
116 	int rc = -1;
117 	char compat[MAX_PROP_LEN];
118 
119 	devp = serial_get_stdout_devp();
120 	if (devp == NULL)
121 		goto err_out;
122 
123 	if (getprop(devp, "compatible", compat, sizeof(compat)) < 0)
124 		goto err_out;
125 
126 	if (!strcmp(compat, "ns16550"))
127 		rc = ns16550_console_init(devp, &serial_cd);
128 	else if (!strcmp(compat, "marvell,mpsc"))
129 		rc = mpsc_console_init(devp, &serial_cd);
130 
131 	/* Add other serial console driver calls here */
132 
133 	if (!rc) {
134 		console_ops.open = serial_open;
135 		console_ops.write = serial_write;
136 		console_ops.edit_cmdline = serial_edit_cmdline;
137 		console_ops.close = serial_close;
138 		console_ops.data = &serial_cd;
139 
140 		return 0;
141 	}
142 err_out:
143 	return -1;
144 }
145