[POWERPC] Fix early btext debug on PowerMac
[linux-2.6] / arch / powerpc / boot / serial.c
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)
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         while (timer++ < 5*1000) {
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         }
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                 devp = finddevice(path);
97                 if (devp == NULL)
98                         goto err_out;
99
100                 if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
101                                 && !strcmp(devtype, "serial"))
102                         return devp;
103         }
104 err_out:
105         return NULL;
106 }
107
108 static struct serial_console_data serial_cd;
109
110 /* Node's "compatible" property determines which serial driver to use */
111 int serial_console_init(void)
112 {
113         void *devp;
114         int rc = -1;
115
116         devp = serial_get_stdout_devp();
117         if (devp == NULL)
118                 goto err_out;
119
120         if (dt_is_compatible(devp, "ns16550"))
121                 rc = ns16550_console_init(devp, &serial_cd);
122         else if (dt_is_compatible(devp, "marvell,mpsc"))
123                 rc = mpsc_console_init(devp, &serial_cd);
124         else if (dt_is_compatible(devp, "fsl,cpm1-scc-uart") ||
125                  dt_is_compatible(devp, "fsl,cpm1-smc-uart") ||
126                  dt_is_compatible(devp, "fsl,cpm2-scc-uart") ||
127                  dt_is_compatible(devp, "fsl,cpm2-smc-uart"))
128                 rc = cpm_console_init(devp, &serial_cd);
129         else if (dt_is_compatible(devp, "mpc5200-psc-uart"))
130                 rc = mpc5200_psc_console_init(devp, &serial_cd);
131         else if (dt_is_compatible(devp, "xilinx,uartlite"))
132                 rc = uartlite_console_init(devp, &serial_cd);
133
134         /* Add other serial console driver calls here */
135
136         if (!rc) {
137                 console_ops.open = serial_open;
138                 console_ops.write = serial_write;
139                 console_ops.close = serial_close;
140                 console_ops.data = &serial_cd;
141
142                 if (serial_cd.getc)
143                         console_ops.edit_cmdline = serial_edit_cmdline;
144
145                 return 0;
146         }
147 err_out:
148         return -1;
149 }