xref: /openbmc/linux/arch/powerpc/boot/serial.c (revision fb574682)
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 static int serial_open(void)
23 {
24 	struct serial_console_data *scdp = console_ops.data;
25 	return scdp->open();
26 }
27 
28 static void serial_write(const char *buf, int len)
29 {
30 	struct serial_console_data *scdp = console_ops.data;
31 
32 	while (*buf != '\0')
33 		scdp->putc(*buf++);
34 }
35 
36 static void serial_edit_cmdline(char *buf, int len, unsigned int timeout)
37 {
38 	int timer = 0, count;
39 	char ch, *cp;
40 	struct serial_console_data *scdp = console_ops.data;
41 
42 	cp = buf;
43 	count = strlen(buf);
44 	cp = &buf[count];
45 	count++;
46 
47 	do {
48 		if (scdp->tstc()) {
49 			while (((ch = scdp->getc()) != '\n') && (ch != '\r')) {
50 				/* Test for backspace/delete */
51 				if ((ch == '\b') || (ch == '\177')) {
52 					if (cp != buf) {
53 						cp--;
54 						count--;
55 						printf("\b \b");
56 					}
57 				/* Test for ^x/^u (and wipe the line) */
58 				} else if ((ch == '\030') || (ch == '\025')) {
59 					while (cp != buf) {
60 						cp--;
61 						count--;
62 						printf("\b \b");
63 					}
64 				} else if (count < len) {
65 						*cp++ = ch;
66 						count++;
67 						scdp->putc(ch);
68 				}
69 			}
70 			break;  /* Exit 'timer' loop */
71 		}
72 		udelay(1000);  /* 1 msec */
73 	} while (timer++ < timeout);
74 	*cp = 0;
75 }
76 
77 static void serial_close(void)
78 {
79 	struct serial_console_data *scdp = console_ops.data;
80 
81 	if (scdp->close)
82 		scdp->close();
83 }
84 
85 static void *serial_get_stdout_devp(void)
86 {
87 	void *devp;
88 	char devtype[MAX_PROP_LEN];
89 	char path[MAX_PATH_LEN];
90 
91 	devp = finddevice("/chosen");
92 	if (devp == NULL)
93 		goto err_out;
94 
95 	if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0 ||
96 		getprop(devp, "stdout-path", path, MAX_PATH_LEN) > 0) {
97 		devp = finddevice(path);
98 		if (devp == NULL)
99 			goto err_out;
100 
101 		if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
102 				&& !strcmp(devtype, "serial"))
103 			return devp;
104 	}
105 err_out:
106 	return NULL;
107 }
108 
109 static struct serial_console_data serial_cd;
110 
111 /* Node's "compatible" property determines which serial driver to use */
112 int serial_console_init(void)
113 {
114 	void *devp;
115 	int rc = -1;
116 
117 	devp = serial_get_stdout_devp();
118 	if (devp == NULL)
119 		goto err_out;
120 
121 	if (dt_is_compatible(devp, "ns16550") ||
122 	    dt_is_compatible(devp, "pnpPNP,501"))
123 		rc = ns16550_console_init(devp, &serial_cd);
124 #ifdef CONFIG_CPM
125 	else if (dt_is_compatible(devp, "fsl,cpm1-scc-uart") ||
126 	         dt_is_compatible(devp, "fsl,cpm1-smc-uart") ||
127 	         dt_is_compatible(devp, "fsl,cpm2-scc-uart") ||
128 	         dt_is_compatible(devp, "fsl,cpm2-smc-uart"))
129 		rc = cpm_console_init(devp, &serial_cd);
130 #endif
131 #ifdef CONFIG_PPC_MPC52XX
132 	else if (dt_is_compatible(devp, "fsl,mpc5200-psc-uart"))
133 		rc = mpc5200_psc_console_init(devp, &serial_cd);
134 #endif
135 #ifdef CONFIG_PPC64_BOOT_WRAPPER
136 	else if (dt_is_compatible(devp, "ibm,opal-console-raw"))
137 		rc = opal_console_init(devp, &serial_cd);
138 #endif
139 
140 	/* Add other serial console driver calls here */
141 
142 	if (!rc) {
143 		console_ops.open = serial_open;
144 		console_ops.write = serial_write;
145 		console_ops.close = serial_close;
146 		console_ops.data = &serial_cd;
147 
148 		if (serial_cd.getc)
149 			console_ops.edit_cmdline = serial_edit_cmdline;
150 
151 		return 0;
152 	}
153 err_out:
154 	return -1;
155 }
156