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 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(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 }