arch/powerpc/boot/serial.c

   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
  20 static int serial_open(void)
  21 {
  22         struct serial_console_data *scdp = console_ops.data;
  23         return scdp->open();
  24 }
  25
  26 static 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
  34 static 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
  75 static void serial_close(void)
  76 {
  77         struct serial_console_data *scdp = console_ops.data;
  78
  79         if (scdp->close)
  80                 scdp->close();
  81 }
  82
  83 static 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         }
 103 err_out:
 104         return NULL;
 105 }
 106
 107 static struct serial_console_data serial_cd;
 108
 109 /* Node's "compatible" property determines which serial driver to use */
 110 int 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         }
 151 err_out:
 152         return -1;
 153 }